Temperature-Dependent Pathways in Carbon Dioxide Electroreduction

Temperature-Dependent Pathways in Carbon Dioxide Electroreduction | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Temperature-Dependent Pathways in Carbon Dioxide Electroreduction Buxing Han, Shiqiang Liu, Yaoyu Yin, Jiahao Yang, Wenling Zhao, and 11 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4925085/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Temperature affects both the thermodynamics of intermediate adsorption and the kinetics of elementary reactions. Despite its extensive study in thermocatalysis, temperature effect is typically overlooked in electrocatalysis. This study investigates how electrolyte temperature influences CO 2 electroreduction over Cu catalysts. Theoretical calculations reveal the significant impact of temperature on *CO and *H intermediate adsorption thermodynamics, water microenvironment at the electrode surface, and the electron density and covalent property of the C–O bond in the *CH–COH intermediate, crucial for the reaction pathways. The theoretical calculations are strongly verified by experimental results over different Cu catalysts. Faradaic efficiency (FE) toward multicarbon (C 2+ ) products is favored at low temperatures. Cu nanorod electrode could achieve a FE C2+ value of 90.1% with a current density of ~ 400 mA cm − 2 at − 3°C. FE C2H4 and FE C2H5OH show opposite trends with decreasing temperature. The FE C2H4 /FE C2H5OH ratio can decrease from 1.86 at 40°C to 0.98 at − 3°C. Introduction Electrochemical CO 2 reduction reaction (CO 2 RR) into high-value products stands as one of the most promising strategies for mitigating CO 2 emissions through the utilization of renewable electricity 1 – 2 . CO 2 RR is a complex process involving multiple reaction pathways that harvest a diverse array of chemical products 3 – 4 . However, the simultaneous occurrence of various CO 2 RR routes alongside the hydrogen evolution reaction (HER) can diminish the selectivity toward desired products 5 – 8 . The adsorption behavior of carbonous intermediates and the intricate water microenvironment at the electrode surface are pivotal factors for influencing these reaction pathways, thereby dictating the distribution of products 9 – 12 . By far, researchers have developed a wide range of electrode materials and electrolytes tailored to finely control intermediate adsorption and the water microenvironment on the electrode surface 13 – 16 . These advancements hold significant promise for steering the CO 2 RR pathway toward desired product with enhanced efficiency and selectivity. The adsorption or dispersion of intermediates, as well as the water microenvironment, are significantly influenced by temperature since they are thermodynamically controlled 17 – 19 . For instance, both C 2 H 4 and C 2 H 5 OH share the same precursor *CH–COH, leading to their simultaneous production 20 – 23 . The kinetics of their distinct reduction pathways can be influenced by temperature, offering a feasible means to control the ratio of C 2 H 4 to C 2 H 5 OH. Hence, adjusting the temperature of the electrolyte to regulate both thermodynamic and kinetics processes emerges as a potent method for steering the CO 2 RR pathway. Consequently, a comprehensive investigation into the relationship between performance and temperature is crucial, providing invaluable insights and guiding significance for optimizing CO 2 RR performance 4 , 24 . CO 2 RR experiments are typically conducted at room temperature, which can vary, for example from − 3°C to 40°C, depending on seasons and regions. The environmental temperature, typically indicated by the electrolyte temperature, can significantly influence the performance of CO 2 RR, yet it is often ignored in CO 2 RR studies 25 – 28 . In this study, we systematically investigated the impact of temperature on CO 2 RR performance. We initiated our study with theoretical calculations, including density functional theory (DFT) and molecular dynamics (MD) simulations, to explore the impact of temperature on intermediate adsorption and kinetics of elementary reactions in CO 2 RR. Subsequently, Cu catalysts were synthesized and employed for CO 2 RR at various temperatures. The theoretical findings aligned well with experimental observations, indicating that lower temperatures favor C 2+ production and promote the formation of C 2 H 5 OH over C 2 H 4 . For instance, a Faradaic efficiency toward multicarbon products (FE C2+ ) of 90.1% was achieved with a current density of ~ 400 mA cm − 2 at − 1.3 V vs RHE over a Cu nanorod (Cu-NR) electrode at − 3°C. Moreover, the FE C2H4 /FE C2H5OH ratio decreases gradually from 1.86 to 0.98 in 1 M KOH as the temperature decreases from 40°C to − 3°C. Further characterizations, including in situ surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), in situ Raman spectroscopy and electrochemical analysis, provide a comprehensive understanding of the temperature effect on CO 2 RR performance. Physical sciences/Chemistry/Catalysis/Electrocatalysis Physical sciences/Chemistry/Electrochemistry/Electrocatalysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction ectrochemical CO 2 reduction reaction (CO 2 RR) into high-value products stands as one of the most promising strategies for mitigating CO 2 emissions through the utilization of renewable electricity 1-2 . CO 2 RR is a complex process involving multiple reaction pathways that harvest a diverse array of chemical products 3-4 . However, the simultaneous occurrence of various CO 2 RR routes alongside the hydrogen evolution reaction (HER) can diminish the selectivity toward desired products 5-8 . The adsorption behavior of carbonous intermediates and the intricate water microenvironment at the electrode surface are pivotal factors for influencing these reaction pathways, thereby dictating the distribution of products 9-12 . By far, researchers have developed a wide range of electrode materials and electrolytes tailored to finely control intermediate adsorption and the water microenvironment on the electrode surface 13-16 . These advancements hold significant promise for steering the CO 2 RR pathway toward desired product with enhanced efficiency and selectivity. The adsorption or dispersion of intermediates, as well as the water microenvironment, are significantly influenced by temperature since they are thermodynamically controlled 17-19 . For instance, both C 2 H 4 and C 2 H 5 OH share the same precursor *CH–COH, leading to their simultaneous production 20-23 . The kinetics of their distinct reduction pathways can be influenced by temperature, offering a feasible means to control the ratio of C 2 H 4 to C 2 H 5 OH. Hence, adjusting the temperature of the electrolyte to regulate both thermodynamic and kinetics processes emerges as a potent method for steering the CO 2 RR pathway. Consequently, a comprehensive investigation into the relationship between performance and temperature is crucial, providing invaluable insights and guiding significance for optimizing CO 2 RR performance 4, 24 . CO 2 RR experiments are typically conducted at room temperature, which can vary, for example from −3 °C to 40 °C, depending on seasons and regions. The environmental temperature, typically indicated by the electrolyte temperature, can significantly influence the performance of CO 2 RR, yet it is often ignored in CO 2 RR studies 25-28 . In this study, we systematically investigated the impact of temperature on CO 2 RR performance. We initiated our study with theoretical calculations, including density functional theory (DFT) and molecular dynamics (MD) simulations, to explore the impact of temperature on intermediate adsorption and kinetics of elementary reactions in CO 2 RR. Subsequently, Cu catalysts were synthesized and employed for CO 2 RR at various temperatures. The theoretical findings aligned well with experimental observations, indicating that lower temperatures favor C 2+ production and promote the formation of C 2 H 5 OH over C 2 H 4 . For instance, a Faradaic efficiency toward multicarbon products (FE C2+ ) of 90.1% was achieved with a current density of ~ 400 mA cm −2 at −1.3 V vs RHE over a Cu nanorod (Cu-NR) electrode at −3 °C. Moreover, the FE C2H4 /FE C2H5OH ratio decreases gradually from 1.86 to 0.98 in 1 M KOH as the temperature decreases from 40 °C to −3 °C. Further characterizations, including in situ surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), in situ Raman spectroscopy and electrochemical analysis, provide a comprehensive understanding of the temperature effect on CO 2 RR performance. Results DFT calculations. DFT calculations can elucidate the adsorption thermodynamics of intermediates and predict reaction mechanisms of CO 2 RR 29 – 30 . This study initiated with DFT calculations to explore the temperature effect on the adsorption Gibbs free energy of intermediates and reaction pathways, modeling the Gibbs free energy for the adsorption of intermediates and potential reaction steps based on a Cu (111) surface. *CO and *H are key intermediates in CO 2 RR and HER, respectively 31 – 32 . The competitive adsorption of *H against *CO frequently results in significant HER, consequently diminishing the selectivity of CO 2 RR. The adsorption configurations and Gibbs free energy profiles of *CO and *H [ΔG ad (CO) and ΔG ad (H)] on Cu(111) are depicted in Supplementary Fig. 2. As the temperature decreases, ΔG ad (CO) becomes increasingly negative, favoring C–C coupling, while ΔG ad (H) gradually approaches zero, inhibiting HER. AIMD simulations. Further AIMD studies were conducted to investigate the impact of temperature on the spontaneous diffusion path of *CO and *H intermediates on the Cu(111) surface. *CO and *H intermediates are predominantly localized at the threefold site as the temperature drops (Fig. 1 a–b). Notably, at higher temperatures, the diffusion of *CO and *H intermediates intensifies on the Cu(111) surface, with spontaneous diffusion observed between two threefold sites. The radial distribution functions (RDFs) between intermediates and the Cu(111) surface reveal a sharp peak centered at 0.3 ~ 0.4 Å at 0 o C and − 40 o C (Fig. 1 c), indicating the average diffusion radius of *CO and *H intermediates around the initial position. When the temperature increases to 40 o C, a broad peak is observed at 0.8 ~ 2.0 Å, signifying spontaneous diffusion at high temperatures. The statistical AIMD results corroborates the static results obtained from ΔG ad values. Since water is the key proton donor, decreasing the supply of water is an effective method for suppressing HER and enhancing the reduction of CO 2 to C 2+ products 35 . Solutions containing K + ions are typically used as electrolytes. An AIMD model incorporating explicit water molecules was further employed to investigate the influence of temperature on the coordination water number of K + . The coordination water numbers of K + are found to be 5.52, 4.64, and 4.12 at − 40°C, 0°C, and 40°C, respectively, indicating a continuous increase in water activity with rising temperature. The peak intensity of RDFs between coordination water and K + becomes more pronounced with increasing temperature, suggesting that water thermal motion intensifies and drifts away from K + at higher temperatures (Fig. 1 e). MD simulations. The concentration of ions can influence water microenvironment, thereby impacting the kinetics of C–C coupling 33 – 34 . Surface OH − concentration is closely linked to the selectivity of C 2+ products during CO 2 RR. MD simulations were conducted to explore the influence of temperature on the distribution of interfacial OH − and CO on the Cu(111) surface. As the temperature decreases, OH − ions migrate closer to the Cu surface (Fig. 1 f), resulting in an increased local concentration of OH − . This promotes C–C coupling and suppresses HER. Additionally, as temperature increases, CO also exhibits a tendency to migrate to the Cu(111) surface, thereby enhancing the probability of C–C coupling. From the discussion above, it is evident that temperature influences the adsorption of *CO and *H intermediates, as well as the interfacial microenvironment, which in turn regulates C–C coupling and HER. However, C–C coupling generating different C 2+ products follows distinct pathways, resulting in diverse selectivity toward a single product. Specifically, C 2 H 4 and C 2 H 5 OH are usually generated simultaneously due to the presence of the same *CH–COH intermediate, which can either undergo hydrogenation via the Eley-Rideal mechanism and dehydration to form *C–CH (C 2 H 4 pathway), or hydrogenation via the Langmuir-Hinshelwood mechanism to produce *CH–CHOH (C 2 H 5 OH pathway) (Fig. 2 a and Supplementary Fig. 6). The energy barriers calculated for these two elementary reactions on the Cu(111) surface are 1.54 and 0.75 eV, respectively (Fig. 2 b). Thereby, starting from crucial branching intermediate *CH–COH, the energy barrier difference between *CH–C formation and *CH–CHOH formation is positive, with a value of 0.79 eV. According to Arrhenius equation \(\:\raisebox{1ex}{${k}_{CH-C}$}\!\left/\:\!\raisebox{-1ex}{${k}_{CH-CHOH}$}\right.=a{e}^{-\frac{\varDelta\:{E}_{TS}}{RT}}\) , \(\:\raisebox{1ex}{${k}_{CH-C}$}\!\left/\:\!\raisebox{-1ex}{${k}_{CH-CHOH}$}\right.\) is negatively correlated with temperature change. Consequently, the formation of C 2 H 4 and C 2 H 5 OH exhibits a reverse trend: high temperatures favor C 2 H 4 formation, whereas low temperatures are conducive to producing C 2 H 5 OH. An AIMD model was utilized to examine the impact of temperature on the bond vibration of the *CH–COH intermediate. The C–O bond on the Cu(111) surface shows a more pronounced response to temperature compared to the C–C and O–H bonds, as indicated by the lowest σ value of the normal distribution fitting (Supplementary Fig. 7). The electronic properties, including projected crystal orbital Hamilton population (pCOHP), electron localization function (ELF) and charge density difference (CDF), were employed to analyze the vibration of the C–O bond in *CH–COH. When changing the C–O bond length to 0.94, 0.97, 1.00, 1.03, and 1.06 times longer than its original length, the corresponding integrated pCOHP (IpCOHP) values are − 9.49, − 8.88, − 8.31, − 7.79, and − 7.33 eV, respectively. The value of IpCOHP becomes less negative as the C–O bond elongates, indicating an increase in the antibonding state of the C–O bond, resulting in the significant activation C–O bond of the *CH–COH intermediate (Fig. 2 c–e). As the C–O bond stretches, the electron density and covalent property of C–O gradually decrease, as revealed by the ELF patterns (Supplementary Figs. 8–9). AIMD results indicate that higher temperatures cause the more obvious stretching of the C–O bond in *CH–COH, resulting in decreased electron density and covalent property of the C–O bond. This, in turn, favors the activation of the C–O bond in *CH–COH for hydrogenation to *C–CH and subsequently to C 2 H 4 . In summary, high temperatures promote the production of C 2 H 4 over C 2 H 5 OH. CO 2 RR at various temperatures. CO 2 RR experiments were carried out using a flow-cell reactor in 1 M KOH, with the temperature of the electrolyte being regulated by a temperature controller. The catalyst employed in the study was Cu-NR catalyst, predominantly oriented along the (111) crystal plane and existed in the Cu(0) state, consistent with the Cu(111) model used for thermotical calculations. Relevant characterizations, such as the X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) image, transmission electron microscope (TEM) image, X-ray Photoelectron Spectroscopy (XPS) spectra and X-ray absorption near edge structure (XANES) spectrum of the Cu electrode are presented in (Supplementary Figs. 10–13). When temperatures are varied, significant variations in product distributions are observed, yet there is relatively small variation in total current density (Fig. 3 a–c and Supplementary Fig. 14). For example, at − 1.3 V vs RHE, FE C2+ increases from 73.6–85.3% as the temperature drops from 40°C to − 3°C (Fig. 3 d). Notably, the increased FE C2+ originates from the inhibited HER and enhanced C–C coupling when decreasing temperature (Fig. 3 e–f). Moreover, as the temperature decreases, the concentration of FE C2H4 gradually diminishes, while that of FE C2H5OH evidently rises. Consequently, the FE C2H4 /FE C2H5OH ratio exhibits a change from 1.86 to 0.98 when transitioning catholyte temperature from 40°C to − 3°C (Fig. 3 d), and the primary product of CO 2 RR shifts from C 2 H 4 to C 2 H 5 OH. To further investigate the relationship between temperature and CO 2 RR selectivity, we conducted experiments using different electrolytes and catalysts. Cu-NR electrode was employed for CO 2 RR in 3 M KOH across various temperatures. When decreasing the electrolyte temperature from 20°C to − 3°C, FE C2+ value increases from 83.1–90.1% over the Cu catalyst electrode at − 0.95 V vs RHE, with the FE C2H4 /FE C2H5OH ratio varying from 1.44 to 0.96 (Supplementary Fig. 15a–b). Additionally, commercial Cu nanoparticles (Cu-NP) with the dominant (111) crystal plane (Supplementary Figs. 10–12) were used as catalysts for CO 2 RR across a temperature range of − 3°C to 20°C using 1 M KOH (Supplementary Fig. 15c–d). A similar trend that lower temperatures favor C–C coupling and C 2 H 5 OH formation is observed over Cu-NP electrode. Variations of CO 2 RR intermediates at various temperatures. In situ ATR-SEIRAS spectra during CO 2 RR over Cu-NR electrode at varying temperatures and potentials were performed to investigate the influence of temperature on water structure and adsorbed intermediates. The OH stretching of water within the range of 3000 ~ 3800 cm − 1 can be divided into isolated water (~ 3600 cm − 1 ), weakly hydrogen-bonded water (~ 3450 cm − 1 ) and strongly hydrogen-bonded water (~ 3250 cm − 1 ) after Gaussian fitting (Fig. 4 a–c) 35 . The proportion of isolated water decreases as the potential becomes increasingly negative, and this variation is more pronounced at lower temperatures (Fig. 4 d). The band center shift is negligible with potential at 40°C and 20°C (Fig. 4 a–b). However, at − 3°C, the band center of OH stretching notably shifts to lower wavenumbers at more negative potentials (Fig. 4 c), indicating the formation of a robust hydrogen bond network. This strong hydrogen bond network at low temperature leads to reduced water activity, effectively suppressing HER. The peaks around 1210 and 1340 cm − 1 are identified as *OCCOH and *OCCHO, respectively (Fig. 4 f–g), representing typical C–C coupling intermediates 33 . Additionally, the presence of the *OC 2 H 5 intermediate at 1330 cm − 1 suggests the formation of C 2 H 5 OH 36 – 37 . Comparatively, at − 3°C, the characteristic peaks corresponding to *OCCOH, *OCCHO, and *OC 2 H 5 shift to lower wavenumbers compared to those at 40°C, indicating increased adsorption of these intermediates. This suggests an enhancement in C–C coupling and the C 2 H 5 OH pathway at lower temperatures 38 . In situ Raman peaks at approximately 360 and 1890/2060 cm − 1 are attributed to the frustrated rotation of Cu–CO and C ≡ O stretching, respectively (Fig. 5 a–b) 39 – 41 . The peak at ~ 700 cm − 1 is assigned to adsorbed *OH species, originating from H 2 O dissociation 42 . Due to the Stark effect, these peaks exhibit blue shifts as the potential becomes more negative over the Cu-NR electrode, indicating a stronger Cu–CO interaction 43 . The Stark tuning slope of Cu–CO increases as temperature varies from 40°C to − 3°C, suggesting that lower electrolyte temperature enhances CO adsorption on the electrode surface (Fig. 5 c). The CO stripping potential shifts to a higher value as the temperature decreases (Fig. 5 f), providing further confirmation of the strengthened interaction between CO and the electrode surface, in accordance the DFT calculations (Supplementary Fig. 2) 44 . The dependence of j C2H4 and j C2H5OH on temperature is illustrated in Fig. 5 d. Both j C2H4 and j C2H5OH exhibit positive correlations with temperature, with C 2 H 4 production showing greater sensitivity to temperature changes (Supplementary Fig. 17). Since both C 2 H 4 and C 2 H 5 OH share the same *CH–COH intermediate, decreasing the temperature evidently suppresses the formation of C 2 H 4 , leading to an increase in FE C2H5OH . The Tafel slopes for the production of C 2+ at 40°C, 20°C, and − 3°C are measured to be 114, 117, and 142 mV·dec − 1 (Fig. 5 e), respectively. These values closely align with the theoretical value of 119 mV·dec − 1 , indicating that the rate-determining step is C–C coupling at all investigated temperatures 45 . The electrochemical double-layer capacitance (C dl ) values are 74.6, 44.7 and 25.9 mF·cm − 2 at 40°C, 20°C, and − 3°C, respectively (Supplementary Fig. 18). The cations exhibit a tendency to migrate from electrolyte to the electrode surface at low temperature (Fig. 1 f), leading to the formation of a closely packed electrochemical double layer, consequently resulting in a decrease in the C dl value at lower temperatures. The partial current density for C 2+ products ( j C2+ ) was normalized on the basis of the electrochemically active surface area (ECSA), (Supplementary Fig. 19). A significantly higher j C2+ is observed at − 3°C, confirming that low temperature is indeed effective in promoting C–C coupling. Conclusion In summary, we have initiated an investigation for the influence of environmental temperature on CO 2 RR performance through theoretical calculations. As temperature decreases, *CO adsorption is favored while HER is inhibited, indicating a preference for C–C coupling. The increased hydration of K + cations at low temperatures results in the reduced water activity, thereby inhibiting HER. The higher energy barrier for the hydrogenation of *CH–COH to *CH–C compared to *CH–CHOH favors the C 2 H 5 OH pathway at lower temperatures. In situ ATR-SEIRAS and Raman spectra, along with electrochemical characterizations, further confirm that *CO adsorption, water activity and the hydrogenation pathway of *CH–COH intermediate are highly temperature-dependent, with C–C coupling and C 2 H 5 OH formation being enhanced at lower temperature. Consequently, FE C2+ achieves a high value of 90.1% at − 3°C over the Cu-NR electrode, with the main C 2+ product transitioning from C 2 H 4 to C 2 H 5 OH solely by decreasing the temperature. We believe this study will bring attention to the temperature effect on CO 2 RR as well as other electrocatalytic reactions, thereby paving the way for optimizing their efficiency. Methods DFT simulations. Density functional theory (DFT) method was used to perform all the spin-polarized calculations of these structures, as implemented in the Vienna ab initio simulation package code (VASP) 46 . Exchange and correlation energies were described in the methods of generalized gradient approximation (GGA) in the form proposed by Perdew–Burke–Ernzerhof (PBE) functional 47 – 48 . The projector-augmented wave (PAW) method was used to describe interaction between valance and core electrons 49 . The plane wave energy cutoff was set to be 500 eV. The structure optimization was relaxed until convergence criteria were met with the energy and force of 1×10 − 5 eV and 0.02 eV/Å, respectively. For structure optimizations, the first Brillouin-zone of such a slab sampled with the Monkhorst − Pack mesh with 3×3×1 grids, were used. To obtain more accurate electronic properties, a denser 7×7×1 k-point grids were further employed 50 . The weak dispersion interaction was described by the DFT-D3 method with the standard parameters proposed by Grimme and his coworkers 51 . To avoid interactions between two neighboring catalyst monolayers under periodic boundary conditions, a minimum vacuum space of 15 Å was set. Solvent effects were included by using implicit solvent model implemented by VASPsol with a dielectric constant of 80 52 . To confirm the bonding nature of the investigated systems by characterizing covalent bond, the electron localization function (ELF) and Critic2 were further employed 53 – 54 . The Crystal Occupation Hamiltonian Population (COHP) method was also employed to investigate the nature of bonding and anti-bonding states, as implemented by LOBSTER code 55 – 56 . Searching transition states (TS) were performed by employing improved dimer method implemented in Henkelman’s scripts, where the convergence force was set to be smaller than 0.02 eV/Å 57–58 . Ab initio molecular dynamics (AIMD) simulations were performed with the Nose-Hoover thermostat approach, at the average temperature of − 40, 0 and 40°C, respectively 59 – 60 . The time step in AIMD was set to be 1 fs. For AIMD simulations, a gamma-centered 1×1×1 k-point grid was used. We carried out 10 ps of AIMD simulation to obtain a well-equilibrated system. To simulate the copper electrode surface, a three-layer and 4×4 periodic cell Cu(111) slab was built, in which two bottom layers were fixed and the top layer was allowed to relax. To simulate the real solution environment, aqueous interface models for kinetic calculations contain 33 explicit water molecules, which could maintain the average water density in the bulk regions being around 1.0 g·cm − 3 . One K atom was located in bulk water as a solvated K + in the solution, and a OH group was also located in bulk water to maintain the electrical neutrality of the periodic system. MD simulations. MD simulations were performed using xTB package 61 . The calculated density of this simulated system was about 1.0 g·cm − 3 , closed to realistic solution circumstances. The MD simulation duration was 20 ps, ensuring that the solution system could reach a stable state, as shown in energy variation diagram (Supplementary Figs. 4–5). The simulations were carried out in the constant particle number, volume and temperature (NVT) ensemble with the thermostat set to a constant temperature of − 40, 0 and 40°C, respectively. After the equilibration period of 10 ps, the snapshots were taken at every 50 fs intervals from the simulation trajectories to analyze distribution of free CO/OH − and CO/OH − adsorbed on catalyst surface. Thermochemistry. The Gibbs free energy difference (∆G) between two neighboring intermediates, named 1 and 2, can be calculated by: $$\:{\varDelta\:\text{G}}_{21}={\text{G}}_{2}-{\text{G}}_{1}$$ 1 For example, in the reaction *CO 2 →*HOCO, where ‘*’ indicates an adsorption site on the catalyst, ΔG was calculated based on the following equation: $$\:\varDelta\:\text{G}=\text{G}\left(\text{*}\text{H}\text{O}\text{C}\text{O}\right)-\text{G}\left(\text{*}{\text{C}\text{O}}_{2}\right)-\text{G}\left({\text{H}}^{+}/{\text{e}}^{-}\right)\:\left(2\right)$$ For this equation, the chemical potential of the H + /e − pair equals to the half value of the chemical potential of the dihydrogen molecule. Given the standard hydrogen electrode conditions, the G(H + /e − ) equals to 1/2G(H 2 ). The Gibbs free energy of intermediates can be calculated by employing the computational hydrogen electrode (CHE) model proposed by Nørskov et al . According to the CHE model, the Gibbs free energy of intermediates can be obtained as following Equation: $$\:G=E+ZPE-TS\:\left(3\right)$$ Adsorbed intermediates were only taken vibrational entropy (S) into account, and the corresponding function is showed in the (4) formula. $$\:\text{S}=-\text{R}\sum\:_{\text{i}}\text{ln}\left(1-{\text{e}}^{\raisebox{1ex}{${-\text{h}\text{v}}_{\text{i}}$}\!\left/\:\!\raisebox{-1ex}{$\text{k}\text{T}$}\right.}\right)+\text{R}\sum\:_{\text{i}}\frac{{\text{h}\text{v}}_{\text{i}}}{\text{k}\text{T}}\frac{{\text{e}}^{\raisebox{1ex}{${-\text{h}\text{v}}_{\text{i}}$}\!\left/\:\!\raisebox{-1ex}{$\text{k}\text{T}$}\right.}}{\left(1-{\text{e}}^{\raisebox{1ex}{${-\text{h}\text{v}}_{\text{i}}$}\!\left/\:\!\raisebox{-1ex}{$\text{k}\text{T}$}\right.}\right)}\:\:\left(4\right)$$ In the equation, R = 8.314 J·mol − 1 K − 1 , k B =1.38·10 − 23 J·K − 1 , h = 6.63·10 − 34 J·s, T = 298.15 K; i is the frequency number; ν i is the vibrational frequency. Under normal conditions, the values of entropy of free gas molecules in the system should be obtained from NIST database. However, values of entropy of free gas molecules of NIST database is only appropriate for above 0 ℃. Therefore, for our systems, all the values of entropy of free gas molecules and adsorbed gas molecules were obtained from vibration frequency calculation. The adsorption free energies of *CO 2 and *H on the pure copper surfaces are defined as $$\:\varDelta\:{\text{G}}_{\text{a}\text{d}}\left({\text{C}\text{O}}_{2}\right)=\text{G}\left(\text{*}{\text{C}\text{O}}_{2}\right)-\text{G}\left(\text{*}\right)-\text{G}\left({\text{C}\text{O}}_{2}\right)\:\left(5\right)$$ $$\:\varDelta\:{\text{G}}_{\text{a}\text{d}}\left(\text{H}\right)=\text{G}\left(*\text{H}\right)-\text{G}\left(\text{*}\right)-\raisebox{1ex}{$1$}\!\left/\:\!\raisebox{-1ex}{$2$}\right.\text{G}\left({\text{H}}_{2}\right)\:\left(6\right)$$ Chemicals. CuSO 4 ·5H 2 O (99.99% metals basis) and C 6 H 5 O 7 Na 3 ·2H 2 O (A. R. grade) were purchased from Aladdin. KOH (A. R. grade), NaOH (A. R. grade), acetone (A. R. grade) and ethanol (A. R. grade) were provided by Sinopharm Chemical Reagent Co., Ltd, China. Cu-NP was purchased from Simga-Aldrich. D 2 O (99.9%), gas diffusion electrode (YLS-30) with 10% PTFE and microporous layer, anion exchange membrane (FAA-3-PK-130) and Nickel foil (purity > 99.8%, thickness 0.5 mm) were obtained from Alfa Aesar China Co., Ltd. Both CO 2 and Ar (Beijing Beiwen Gas Chemical Industry Co., Ltd., research grade) has purities of 99.999% and used as received. Aqueous solutions were prepared with deionized water (Millipore 18.2 MΩ cm). Preparation of the Cu-NR electrode . Initially, 1.3 mmol of CuSO 4 ·5H 2 O and 0.91 mmol of C 6 H 5 O 7 Na 3 ·2H 2 O were dissolved into the 40 mL of deionized water with stirring for 15 min at room temperature. 5.3 mmol of NaOH was then added into the mixture and further stirred for 2.5 h. The resultant solution was transferred to autoclave and kept at 160°C for 12 h. When the hydrothermal procedure was finished, the obtained product was washed with deionized water and absolute ethanol for three times, alternately. The obtained product was dried at 60°C for 8 h and then annealed at 400°C for 4 h in air 62 . Subsequently, 10 mg of the as-prepared material and 10 µL of Nafion solution (5 wt %) were added into 1 mL of isopropanol and sonicated for 30 min. The as-prepared ink was then drop-coated on the polytetrafluoroethylene (PTFE)-hydrophobized carbon fiber paper (Toray, YLS-30T GDL) and dried. Finally, the as-prepared electrodes underwent electroreduction in 1 M KOH at -0.5 V vs RHE for 10 minutes, resulting in the formation of Cu-NR electrode. Material characterizations . The morphology was characterized by SEM TESCAN MIRA LMS and TEM Thermo Fisher Talos F200S G2. XRD was conducted using an X-ray diffractometer (PANalytical Empyrean) with a scan speed of 5 o ·min − 1 . XPS analysis was conducted on the Thermo Scientific ESCALab 250Xi (USA) using 200 W monochromatic Al Kα radiation. XANES data were collected at 1W2B station in Beijing Synchrotron Radiation Facility (BSRF) operated at 2.5 GeV with a maximum current of 250 mA. CO 2 RR experiments. CO 2 RR experiments were conducted using a CHI-660e electrochemical workstation equipped with a high current amplifier CHI-680c in an electrochemical flow-cell consisted of a gas chamber, a cathodic chamber and an anodic chamber. The anion exchange membrane (FumasepFAA-3-PK-130) was used to separate the anodic and cathodic chambers, and a Hg/HgO electrode (1 M KOH electrolyte used as the filling solution) and Nickel foil were used as the reference and counter electrodes, respectively. All potentials were converted to the RHE reference scale using the relation: E RHE =E Hg/HgO +0.098 + 0.059×pH. In the electrochemical CO 2 RR performance tests, KOH was used as the electrolyte, and the electrolyte was circulated through the cathodic and anodic chambers using peristaltic pumps at a rate of 30 mL·min − 1 . The flow rate of CO 2 gas through the gas chamber was controlled to be 30 sccm using a digital gas flow controller. To control the temperature of electrolyte, the electrolyte was placed in refrigerant at different temperatures. The gaseous product in the electrochemical experiment was collected into a gas bag and analyzed by gas chromatography (GC, HP 4890D). The liquid products were quantified using nuclear magnetic resonance spectroscopy ( 1 H NMR). 1 H NMR spectra of freshly acquired samples were collected on a Bruker Avance III 400 HD spectrometer. Dimethyl sulfoxide (DMSO) was used as internal standard. The Faradaic efficiency (FE) of a product can be calculated by: $$\:\text{F}\text{E}=\frac{\text{n}}{\raisebox{1ex}{$\text{Q}$}\!\left/\:\!\raisebox{-1ex}{$\text{N}\text{F}$}\right.}\times\:100\text{%}（1）$$ where Q is charge (C), F is Faradaic constant (96485 C·mol − 1 ), N is the number of transferred electrons to generate desired products, n is the moles of products. For the H 2 , CO, CH 4 , C 2 H 4 , HCOOH, CH 3 OH, CH 3 COOH, CH 3 CH 2 OH and n-C 3 H 7 OH, the N is 2, 2, 8, 12, 2, 6, 8, 12 and 18, respectively. Electrochemical tests. The variation in the partial current density vs applied potential was obtained via stepped potential electrolysis, and Tafel plots were generated from these data. C dl was measured by the capacitive current associated with double-layer charging from the scan-rate dependence of cyclic voltammogram (CV). The CV tests were performed in a flow-cell with three electrodes, ranging from 0.25 V to 0.15 V vs RHE. 1 M KOH solution was used as the electrolyte. The scan rates were 10, 20, 30, 40, 60, 80, 100 and 120 mV·s − 1 . CO stripping experiments were carried out using 0.1 M KHCO 3 as the electrolyte in an H-type cell. Prior to the experiment, all catalyst was electrolyzed at − 0.6 V vs RHE for 5 min to fully remove the oxidation species in 0.1 M Ar-saturated KHCO 3 . CO was then introduced into the cell and electrolyzed at − 0.8 V vs RHE for 10 min to obtain CO adsorption at the cathode. Ar was then flowed into the electrolyte to remove residual CO. CV curves were then conducted at a scan rate of 50 mV·s − 1 . In situ characterizations. In situ ATR-SEIRAS experiments were conducted in a modified electrochemical cell that integrated into a BRUKER VERTEX 70v spectrometer cooled by liquid nitrogen. The catalyst was spread on gold-plated silicon prism. A Pt electrode and an Ag/AgCl electrode were used as counter and reference electrodes, respectively. The 1 M KHCO 3 aqueous solution was used as electrolyte at various temperatures. In situ Raman experiments were conducted in a flow-cell equipped with a quartz window provided by GaossUnion (Tianjin) Photoelectric Technology Company, utilizing a Horiba LabRAM HR Evolution Raman microscope. A 533 nm excitation laser was used and signals were recorded using a 30 s integration and by averaging two scans. The Cu-NR electrode was used as working electrode. A graphite electrode and a Hg/HgO electrode were used as counter and reference electrodes, respectively. The anion exchange membrane was used to separate counter electrode and working electrode. The circulated 1 M KOH aqueous solution was used as electrolyte at various temperatures. Declarations Competing interests The authors declare no competing interests. Author Information Correspondence and requests for materials should be addressed to X.K. ( [email protected] ) or B.H. ( [email protected] ). Author Contributions S.L.: DFT calculations and MD simulation. S.L., Y.Y., J.Y.: syntheses and characterizations of catalysts. S.L., W.Z., M.Z. and H.Q.: CO 2 RR experiments and electrochemical characterizations. Y.W., H.W. and X.T.: In situ ATR-SEIRAS and Raman experiments. J.J.: analysis of XAS data. Y.X., X.S., Q.Z. and M. F.: mechanism analysis. X.K. and B.H.: overall design and direction of the project. S.L., X.K. and B.H.: preparation of the manuscript with help from all authors. Acknowledgments The work was supported by the National Natural Science Foundation of China (22273108, 22293015, 22121002), Beijing Natural Science Foundation (2222043), CAS Project for Young Scientists in Basic Research (YSBR-050) and Innovation Program of the IHEP (2023000034), Photon Science Center for Carbon Neutrality. The X-ray absorption spectroscopy measurements were performed at Beijing Synchrotron Radiation Facility (BSRF). References Fan M et al (2023) Cationic-group-functionalized electrocatalysts enable stable acidic CO 2 electrolysis. Nat Catal 6:763–772 Ding J et al (2023) A tin-based tandem electrocatalyst for CO 2 reduction to ethanol with 80% selectivity. Nat Energy 8:1386–1394 Yang P, Gao M (2023) Enrichment of reactants and intermediates for electrocatalytic CO 2 reduction. Chem Soc Rev 52:4343–4380 Wang G et al (2021) Electrocatalysis for CO 2 conversion: From fundamentals to value-added products. Chem Soc Rev 50:4993–5061 Ma W et al (2021) Electrocatalytic reduction of CO 2 and CO to multi-carbon compounds over Cu-based catalysts. Chem Soc Rev 50:12897–12914 Ma Z et al (2022) CO 2 electroreduction to multicarbon products in strongly acidic electrolyte via synergistically modulating the local microenvironment. Nat Commun 13:7596 Jiao J et al (2024) Steering the reaction pathway of CO 2 electroreduction by tuning the coordination number of copper catalysts. J Am Chem Soc 146:15917–15925 Yu X et al (2024) Coverage enhancement accelerates acidic CO 2 electrolysis at ampere-level current with high energy and carbon efficiencies. Nat Commun 15:1711 Zeng M et al (2024) Reaction environment regulation for electrocatalytic CO 2 reduction in acids. Angew Chem Int Ed 63:e202404574 He M et al (2022) Selective enhancement of methane formation in electrochemical CO 2 reduction enabled by a Raman-inactive oxygen-containing species on Cu. ACS Catal 12:6036–6046 Timoshenko J et al (2022) Steering the structure and selectivity of CO 2 electroreduction catalysts by potential pulses. Nat Catal 5:259–267 Shi C, Hansen HA, Lausche AC, Nørskov JK (2014) Trends in electrochemical CO 2 reduction activity for open and close-packed metal surfaces. Phys Chem Chem Phys 16:4720–4727 Wang Y et al (2024) Strong hydrogen-bonded interfacial water inhibiting hydrogen evolution kinetics to promote electrochemical CO 2 reduction to C 2+ . ACS Catal 14:3457–3465 Feng J et al (2023) Improving CO 2 -to-C 2+ product electroreduction efficiency via atomic Lanthanide dopant-induced tensile-strained CuO x catalysts. J Am Chem Soc 145:9857–9866 Ge W et al (2022) Dynamically formed surfactant assembly at the electrified electrode–electrolyte interface boosting CO 2 electroreduction. J Am Chem Soc 144:6613–6622 Deng T et al (2024) Polymer modification strategy to modulate reaction microenvironment for enhanced CO 2 electroreduction to ethylene. Angew Chem Int Ed 63:e202313796 Kaneco S, Iiba K, Ohta K, Mizuno T, Saji A (1998) Electrochemical reduction of CO 2 on Au in KOH + methanol at low temperature. J Electroanal Chem 441:215–220 Kaneco S, Iiba K, Ohta K, Mizuno T, Saji A (1998) Electrochemical reduction of CO 2 at an Ag electrode in KOH-methanol at low temperature. Electrochim Acta 44:573–578 Li K et al (2023) Superhydrophobicity-enabled efficient Electrocatalytic CO 2 reduction at a high temperature. ACS Catal 13:9346–9351 Ouyang Y et al (2023) Selectivity of electrochemical CO 2 reduction toward ethanol and ethylene: the key role of surface-active hydrogen. ACS Catal 13:15448–15456 Cheng T, Xiao H, Goddard WA (2017) Full atomistic reaction mechanism with kinetics for CO reduction on Cu(100) from ab initio molecular dynamics free-energy calculations at 298 K. Proc. Natl. Acad. Sci. U.S.A. 114, 1795–1800 Calle-Vallejo F, Koper MTM (2013) Theoretical considerations on the electroreduction of CO to C 2 species on Cu(100) electrodes. Angew Chem Int Ed 52:7282–7285 Wan M et al (2023) Enhanced CO 2 reactive capture and conversion using aminothiolate ligand-metal interface. J Am Chem Soc 145:26038–26051 Lin L et al (2021) Temperature-dependent CO 2 electroreduction over Fe-N-C and Ni-N-C single-atom catalysts. Angew Chem Int Ed 60:26582–26586 Vos RE et al (2023) How temperature affects the selectivity of the electrochemical CO 2 reduction on copper. ACS Catal 13:8080–8091 Jo SW, Kim JY, Lee MW, Kim Y, Ahn HS (2023) Highly selective reduction of CO 2 to methane induced by subzero depression of the electrode surface temperature. ACS Catal 13:5122–5126 Vos RE, Koper MTM (2022) The effect of temperature on the cation-promoted electrochemical CO 2 reduction on gold. ChemElectroChem 9, e202200239 Ahn ST, Abu-Baker I, Palmore GTR (2017) Electroreduction of CO 2 on polycrystalline copper: Effect of temperature on product selectivity. Catal Today 288:24–29 Vavra J et al (2024) Solution-based Cu + transient species mediate the reconstruction of copper electrocatalysts for CO 2 reduction. Nat Catal 7:89–97 Zhao Q, Martirez JMP, Carter EA (2021) Revisiting understanding of electrochemical CO 2 reduction on Cu(111): Competing proton-coupled electron transfer reaction mechanisms revealed by embedded correlated wavefunction theory. J Am Chem Soc 143:6152–6164 Zheng M et al (2022) Electrocatalytic CO 2 -to-C 2+ with ampere-level current on heteroatom-engineered copper via tuning *CO intermediate coverage. J Am Chem Soc 144:14936–14944 Xie Y et al (2022) High carbon utilization in CO 2 reduction to multi-carbon products in acidic media. Nat Catal 5:564–570 Yang X et al (2024) Cation-induced interfacial hydrophobic microenvironment promotes the C–C coupling in electrochemical CO 2 reduction. J Am Chem Soc 146:5532–5542 Gorthy S et al (2023) Theoretical insights into the effects of KOH concentration and the role of OH – in the electrocatalytic reduction of CO 2 on Au. ACS Catal 13:12924–12940 Schaefer J, Backus EHG, Nagata Y, Bonn M (2016) Both inter- and intramolecular coupling of O–H groups determine the vibrational response of the water/air interface. J Phys Chem Lett 7:4591–4595 Wang P et al (2022) Boosting electrocatalytic CO 2 -to-ethanol production via asymmetric C-C coupling. Nat Commun 13:3754 Sun W et al (2022) V-Doped Cu 2 Se hierarchical nanotubes enabling flow-cell CO 2 electroreduction to ethanol with high efficiency and selectivity. Angew Chem Int Ed 34:2207691 Wu Z et al (2022) Identification of Cu(100)/Cu(111) interfaces as superior active sites for CO dimerization during CO 2 electroreduction. J Am Chem Soc 144:259–269 Nguyen TN et al (2022) Catalyst regeneration via chemical oxidation enables long-term electrochemical carbon dioxide reduction. J Am Chem Soc 144:13254–13265 Cao Y et al (2023) Surface hydroxide promotes CO 2 electrolysis to ethylene in acidic conditions. Nat Commun 14:2387 Amirbeigiarab R et al (2023) Atomic-scale surface restructuring of copper electrodes under CO 2 electroreduction conditions. Nat Catal 6:837–846 Li H, Wei P, Gao D, Wang G (2022) In situ Raman spectroscopy studies for electrochemical CO 2 reduction over Cu catalysts. Curr Opin Green Sustain Chem 34:100589 Cui Y et al (2023) N x C-induced switching of methane and ethylene products’ selectivity from CO 2 electroreduction over Cu catalyst. ACS Catal 13:11625–11633 Wei Z et al (2019) Optimizing alkyne hydrogenation performance of Pd on carbon in situ decorated with oxygen-deficient TiO 2 by integrating the reaction and diffusion. ACS Catal 9:10656–10667 Li J et al (2021) Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper. Nat Commun 12:3264 Kresse G, Furthmüller J (1996) Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput Mater Sci 6:15–50 Perdew JP et al (1992) Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation. Phys Rev B 46:6671–6687 Perdew JP, Wang Y (1992) Accurate and simple analytic representation of the electron-gas correlation energy. Phys Rev B 45:13244–13249 Blöchl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953–17979 Monkhorst HJ, Pack JD (1976) Special points for Brillouin-zone integrations. Phys Rev B 13:5188–5192 Grimme S, Antony J, Ehrlich S, Krieg H (2010) A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J Chem Phys 132:154104 Mathew K, Sundararaman R, Letchworth-Weaver K, Arias TA, Hennig RG (2014) Implicit solvation model for density-functional study of nanocrystal surfaces and reaction pathways. J Chem Phys 140:084106 Savin A, Nesper R, Wengert S, Fässler TF (1997) ELF: The electron localization function. Angew Chem Int Ed 36:1808–1832 Otero-de-la-Roza A, Johnson ER, Luaña V (2014) Critic2: A program for real-space analysis of quantum chemical interactions in solids. Comput Phys Commun 185:1007–1018 Dronskowski R, Bloechl PE (1993) Crystal orbital Hamilton populations (COHP): Energy-resolved visualization of chemical bonding in solids based on density-functional calculations. J Phys Chem 97:8617–8624 Nelson R et al (2020) Local orbital projections, atomic charges, and chemical-bonding analysis from projector-augmented-wave-based density-functional theory. J Comput Chem 41:1931–1940 Henkelman GA, Uberuaga BP, Jónsson H (2000) A climbing image nudged elastic band method for finding saddle points and minimum energy paths. J Chem Phys 113:9901–9904 Henkelman G, Jónsson H (1999) A dimer method for finding saddle points on high dimensional potential surfaces using only first derivatives. J Chem Phys 111:7010–7022 Bussi G, Donadio D, Parrinello M (2007) Canonical sampling through velocity rescaling. J Chem Phys 126:014101 Nosé S (1984) A unified formulation of the constant temperature molecular dynamics methods. J Chem Phys 81:511–519 Bannwarth C et al (2021) Extended tight-binding quantum chemistry methods. WIREs Comput Mol Sci 11:e1493 Chen X et al (2021) Room-temperature NO 2 sensing properties and mechanism of CuO nanorods with Au functionalization. Sens Actuat B-Chem 328:129070 Additional Declarations There is NO Competing Interest. 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12:41:31","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4925085/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4925085/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":63590881,"identity":"ec74f287-cef5-43fd-b25e-6c193c2c586c","added_by":"auto","created_at":"2024-08-30 03:00:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":137701,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTemperature-dependent adsorption on the Cu(111) surface. \u003c/strong\u003e(a–b) Diffusion trajectories of the adsorbed *CO (a) and *H (b) intermediate. Arrows in \u003cstrong\u003ea\u003c/strong\u003e and \u003cstrong\u003eb\u003c/strong\u003e indicate the approximate direction of diffusion. (c) RDFs between different intermediates and electrode surface. (d) Schematic diagram for the coordination water of K\u003csup\u003e+\u003c/sup\u003e. The bronze, red, gray and white balls represent Cu atom, O atom, C atom and H atoms, respectively. (e) RDFs between coordination water and K\u003csup\u003e+\u003c/sup\u003e. (f) Allocations of free CO/OH\u003csup\u003e−\u003c/sup\u003e (bule) and adsorbed on the electrode surface (brown).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/856ba853c792d0d991b18360.png"},{"id":63591243,"identity":"461b70c9-4feb-4666-8b9b-7d309df354c9","added_by":"auto","created_at":"2024-08-30 03:08:50","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":186444,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTheoretical calculations for the activation of *CH–COH intermediate at various temperatures.\u003c/strong\u003e (a–b) Schematic diagram (a) and energy barriers (b) for the hydrogenation of *CH–COH. The bronze, red, gray and white balls represent Cu, O, C and H atoms, respectively. (c–e) The pCOHP curves (left) and ELF patterns (right) for the C–O bonds in *CH–COH when the C–O bond length is changed to 0.94 (c), 1 (d) and 1.06 (e) times to the original length.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/38148d5da767607673090aea.png"},{"id":63591242,"identity":"b1cb604b-d590-40ce-8a7c-ce2fdeec3e2c","added_by":"auto","created_at":"2024-08-30 03:08:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":116647,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003eRR performance in 1 M KOH over Cu-NR electrode at various temperatures.\u003c/strong\u003e (a–c) Plot of FE of various products vs potential at 40 °C (a), 20 °C (b) and −3 °C (c). (d) Plot of FE\u003csub\u003eC2+\u003c/sub\u003e vs temperature at −1.3 V vs RHE. (e) Plot of FE\u003csub\u003eC2H4\u003c/sub\u003e and FE\u003csub\u003eC2H5OH\u003c/sub\u003e vs temperature at −1.3 V vs RHE. (f) Plot of FE\u003csub\u003eCO\u003c/sub\u003e and FE\u003csub\u003eH2\u003c/sub\u003e vs temperature at −1.3 V vs RHE.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/322e62d505540cf331d4c645.png"},{"id":63590883,"identity":"5dd488b9-6bc5-41ff-a989-a0c5315b8748","added_by":"auto","created_at":"2024-08-30 03:00:50","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":190773,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIn situ ATR-SEIRAS spectra over Cu-NR electrode at various temperatures during CO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003eRR. \u003c/strong\u003e(a–c) In situ ATR-SEIRAS spectra of interfacial water at 40 °C (a), 20 °C (b), −3 °C (c). (d) Normalized peak area of isolated water at ∼3600 cm\u003csup\u003e–1\u003c/sup\u003e. (e) Schematic illustration of the hydrogen bonding structure of interfacial water. The bronze, red, gray and white balls represent Cu, O, C and H atoms, respectively. (f–g) In situ ATR-SEIRAS spectra at 40 °C (f) and −3 °C (g).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/7089ed2ce6847381d71c8ff6.png"},{"id":63590884,"identity":"6e67e25b-b439-4a6a-be54-2b0a9faee8ae","added_by":"auto","created_at":"2024-08-30 03:00:50","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":82975,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eIn situ Raman spectra and electrochemical tests of CO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003eRR over Cu-NR electrode at various temperatures. \u003c/strong\u003e(a–b) In situ Raman spectra at 40 °C (a) and −3 °C (b). (c) Plot of Raman peak shift of *CO stretching vs potential. The slope of the fitting line represents the Stark tuning slope. (d) Relationship between partial current density of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e/C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH and electrolyte temperature. (e) Tafel Plots. (f) CO stripping curves.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/37f627e069d287fce759af39.png"},{"id":66366509,"identity":"cc7aaaaa-1921-44c7-926a-228974229d75","added_by":"auto","created_at":"2024-10-11 03:13:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1458898,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/9989ff32-77e0-4e7f-a1a2-4ecef9a1b05d.pdf"},{"id":63590885,"identity":"2a00affa-0f9e-45c7-8d40-10175d1d334f","added_by":"auto","created_at":"2024-08-30 03:00:51","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":7211267,"visible":true,"origin":"","legend":"","description":"","filename":"SUPPLEMENTARYINFORMATION.docx","url":"https://assets-eu.researchsquare.com/files/rs-4925085/v1/b0a8b75738a5cf9389491102.docx"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Temperature-Dependent Pathways in Carbon Dioxide Electroreduction","fulltext":[{"header":"Introduction","content":"\u003cp\u003eectrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction reaction (CO\u003csub\u003e2\u003c/sub\u003eRR) into high-value products stands as one of the most promising strategies for mitigating CO\u003csub\u003e2\u003c/sub\u003e emissions through the utilization of renewable electricity\u003csup\u003e1-2\u003c/sup\u003e. CO\u003csub\u003e2\u003c/sub\u003eRR is a complex process involving multiple reaction pathways that harvest a diverse array of chemical products\u003csup\u003e3-4\u003c/sup\u003e. However, the simultaneous occurrence of various CO\u003csub\u003e2\u003c/sub\u003eRR routes alongside the hydrogen evolution reaction (HER) can diminish the selectivity toward desired products\u003csup\u003e5-8\u003c/sup\u003e. The adsorption behavior of carbonous intermediates and the intricate water microenvironment at the electrode surface are pivotal factors for influencing these reaction pathways, thereby dictating the distribution of products\u003csup\u003e9-12\u003c/sup\u003e. By far, researchers have developed a wide range of electrode materials and electrolytes tailored to finely control intermediate adsorption and the water microenvironment on the electrode surface\u003csup\u003e13-16\u003c/sup\u003e. These advancements hold significant promise for steering the CO\u003csub\u003e2\u003c/sub\u003eRR pathway toward desired product with enhanced efficiency and selectivity.\u003c/p\u003e\n\u003cp\u003eThe adsorption or dispersion of intermediates, as well as the water microenvironment, are significantly influenced by temperature since they are thermodynamically controlled\u003csup\u003e17-19\u003c/sup\u003e. For instance, both C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH share the\u0026nbsp;same precursor *CH\u0026ndash;COH, leading to their simultaneous production\u003csup\u003e20-23\u003c/sup\u003e. The kinetics of their distinct reduction pathways can be influenced by temperature, offering a feasible means to control the ratio of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e to C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH. Hence, adjusting the temperature of the electrolyte to regulate both thermodynamic and kinetics processes emerges as a potent\u0026nbsp;method for steering the CO\u003csub\u003e2\u003c/sub\u003eRR pathway.\u0026nbsp;Consequently, a comprehensive investigation into the relationship between performance and temperature is crucial, providing invaluable insights and guiding significance for optimizing CO\u003csub\u003e2\u003c/sub\u003eRR performance\u003csup\u003e4, 24\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003eRR experiments are typically conducted at room temperature, which can vary, for example from \u0026minus;3 \u0026deg;C to 40 \u0026deg;C, depending on seasons and regions. The environmental temperature, typically indicated by the electrolyte temperature, can significantly influence the performance of CO\u003csub\u003e2\u003c/sub\u003eRR, yet it is often ignored in CO\u003csub\u003e2\u003c/sub\u003eRR studies\u003csup\u003e25-28\u003c/sup\u003e. In this study, we systematically investigated the impact of temperature on CO\u003csub\u003e2\u003c/sub\u003eRR performance. We initiated our study with theoretical calculations, including density functional theory (DFT) and molecular dynamics (MD) simulations, to explore the impact of temperature on intermediate adsorption and kinetics of elementary reactions in CO\u003csub\u003e2\u003c/sub\u003eRR. Subsequently, Cu catalysts were synthesized and employed for CO\u003csub\u003e2\u003c/sub\u003eRR at various temperatures. The theoretical findings aligned well with experimental observations, indicating that lower temperatures favor C\u003csub\u003e2+\u003c/sub\u003e production and promote the formation of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH over C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e. For instance, a Faradaic efficiency toward multicarbon products (FE\u003csub\u003eC2+\u003c/sub\u003e) of 90.1% was achieved with a current density of ~ 400 mA cm\u003csup\u003e\u0026minus;2\u003c/sup\u003e at \u0026minus;1.3 V vs RHE over a Cu nanorod (Cu-NR) electrode at \u0026minus;3 \u0026deg;C. Moreover, the FE\u003csub\u003eC2H4\u003c/sub\u003e/FE\u003csub\u003eC2H5OH\u003c/sub\u003e ratio decreases gradually from 1.86 to 0.98 in 1 M KOH as the temperature decreases from 40 \u0026deg;C to \u0026minus;3 \u0026deg;C. Further characterizations, including in situ surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), in situ Raman spectroscopy and electrochemical analysis, provide a comprehensive understanding of the temperature effect on CO\u003csub\u003e2\u003c/sub\u003eRR performance.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cb\u003eDFT calculations.\u003c/b\u003e DFT calculations can elucidate the adsorption thermodynamics of intermediates and predict reaction mechanisms of CO\u003csub\u003e2\u003c/sub\u003eRR\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. This study initiated with DFT calculations to explore the temperature effect on the adsorption Gibbs free energy of intermediates and reaction pathways, modeling the Gibbs free energy for the adsorption of intermediates and potential reaction steps based on a Cu (111) surface. *CO and *H are key intermediates in CO\u003csub\u003e2\u003c/sub\u003eRR and HER, respectively\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e. The competitive adsorption of *H against *CO frequently results in significant HER, consequently diminishing the selectivity of CO\u003csub\u003e2\u003c/sub\u003eRR. The adsorption configurations and Gibbs free energy profiles of *CO and *H [ΔG\u003csub\u003ead\u003c/sub\u003e(CO) and ΔG\u003csub\u003ead\u003c/sub\u003e(H)] on Cu(111) are depicted in Supplementary Fig.\u0026nbsp;2. As the temperature decreases, ΔG\u003csub\u003ead\u003c/sub\u003e(CO) becomes increasingly negative, favoring C\u0026ndash;C coupling, while ΔG\u003csub\u003ead\u003c/sub\u003e(H) gradually approaches zero, inhibiting HER.\u003c/p\u003e \u003cp\u003e \u003cb\u003eAIMD simulations.\u003c/b\u003e Further AIMD studies were conducted to investigate the impact of temperature on the spontaneous diffusion path of *CO and *H intermediates on the Cu(111) surface. *CO and *H intermediates are predominantly localized at the threefold site as the temperature drops (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea\u0026ndash;b). Notably, at higher temperatures, the diffusion of *CO and *H intermediates intensifies on the Cu(111) surface, with spontaneous diffusion observed between two threefold sites. The radial distribution functions (RDFs) between intermediates and the Cu(111) surface reveal a sharp peak centered at 0.3\u0026thinsp;~\u0026thinsp;0.4 \u0026Aring; at 0 \u003csup\u003eo\u003c/sup\u003eC and \u0026minus;\u0026thinsp;40 \u003csup\u003eo\u003c/sup\u003eC (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec), indicating the average diffusion radius of *CO and *H intermediates around the initial position. When the temperature increases to 40 \u003csup\u003eo\u003c/sup\u003eC, a broad peak is observed at 0.8\u0026thinsp;~\u0026thinsp;2.0 \u0026Aring;, signifying spontaneous diffusion at high temperatures. The statistical AIMD results corroborates the static results obtained from ΔG\u003csub\u003ead\u003c/sub\u003e values.\u003c/p\u003e \u003cp\u003eSince water is the key proton donor, decreasing the supply of water is an effective method for suppressing HER and enhancing the reduction of CO\u003csub\u003e2\u003c/sub\u003e to C\u003csub\u003e2+\u003c/sub\u003e products\u003csup\u003e35\u003c/sup\u003e. Solutions containing K\u003csup\u003e+\u003c/sup\u003e ions are typically used as electrolytes. An AIMD model incorporating explicit water molecules was further employed to investigate the influence of temperature on the coordination water number of K\u003csup\u003e+\u003c/sup\u003e. The coordination water numbers of K\u003csup\u003e+\u003c/sup\u003e are found to be 5.52, 4.64, and 4.12 at \u0026minus;\u0026thinsp;40\u0026deg;C, 0\u0026deg;C, and 40\u0026deg;C, respectively, indicating a continuous increase in water activity with rising temperature. The peak intensity of RDFs between coordination water and K\u003csup\u003e+\u003c/sup\u003e becomes more pronounced with increasing temperature, suggesting that water thermal motion intensifies and drifts away from K\u003csup\u003e+\u003c/sup\u003e at higher temperatures (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee).\u003c/p\u003e \u003cp\u003e \u003cb\u003eMD simulations.\u003c/b\u003e The concentration of ions can influence water microenvironment, thereby impacting the kinetics of C\u0026ndash;C coupling\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. Surface OH\u003csup\u003e\u0026minus;\u003c/sup\u003e concentration is closely linked to the selectivity of C\u003csub\u003e2+\u003c/sub\u003e products during CO\u003csub\u003e2\u003c/sub\u003eRR. MD simulations were conducted to explore the influence of temperature on the distribution of interfacial OH\u003csup\u003e\u0026minus;\u003c/sup\u003e and CO on the Cu(111) surface. As the temperature decreases, OH\u003csup\u003e\u0026minus;\u003c/sup\u003e ions migrate closer to the Cu surface (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef), resulting in an increased local concentration of OH\u003csup\u003e\u0026minus;\u003c/sup\u003e. This promotes C\u0026ndash;C coupling and suppresses HER. Additionally, as temperature increases, CO also exhibits a tendency to migrate to the Cu(111) surface, thereby enhancing the probability of C\u0026ndash;C coupling.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFrom the discussion above, it is evident that temperature influences the adsorption of *CO and *H intermediates, as well as the interfacial microenvironment, which in turn regulates C\u0026ndash;C coupling and HER. However, C\u0026ndash;C coupling generating different C\u003csub\u003e2+\u003c/sub\u003e products follows distinct pathways, resulting in diverse selectivity toward a single product. Specifically, C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH are usually generated simultaneously due to the presence of the same *CH\u0026ndash;COH intermediate, which can either undergo hydrogenation via the Eley-Rideal mechanism and dehydration to form *C\u0026ndash;CH (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e pathway), or hydrogenation via the Langmuir-Hinshelwood mechanism to produce *CH\u0026ndash;CHOH (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH pathway) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea and Supplementary Fig.\u0026nbsp;6). The energy barriers calculated for these two elementary reactions on the Cu(111) surface are 1.54 and 0.75 eV, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). Thereby, starting from crucial branching intermediate *CH\u0026ndash;COH, the energy barrier difference between *CH\u0026ndash;C formation and *CH\u0026ndash;CHOH formation is positive, with a value of 0.79 eV. According to Arrhenius equation \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\raisebox{1ex}{${k}_{CH-C}$}\\!\\left/\\:\\!\\raisebox{-1ex}{${k}_{CH-CHOH}$}\\right.=a{e}^{-\\frac{\\varDelta\\:{E}_{TS}}{RT}}\\)\u003c/span\u003e\u003c/span\u003e, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\raisebox{1ex}{${k}_{CH-C}$}\\!\\left/\\:\\!\\raisebox{-1ex}{${k}_{CH-CHOH}$}\\right.\\)\u003c/span\u003e\u003c/span\u003eis negatively correlated with temperature change. Consequently, the formation of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH exhibits a reverse trend: high temperatures favor C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e formation, whereas low temperatures are conducive to producing C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH. An AIMD model was utilized to examine the impact of temperature on the bond vibration of the *CH\u0026ndash;COH intermediate. The C\u0026ndash;O bond on the Cu(111) surface shows a more pronounced response to temperature compared to the C\u0026ndash;C and O\u0026ndash;H bonds, as indicated by the lowest σ value of the normal distribution fitting (Supplementary Fig.\u0026nbsp;7). The electronic properties, including projected crystal orbital Hamilton population (pCOHP), electron localization function (ELF) and charge density difference (CDF), were employed to analyze the vibration of the C\u0026ndash;O bond in *CH\u0026ndash;COH. When changing the C\u0026ndash;O bond length to 0.94, 0.97, 1.00, 1.03, and 1.06 times longer than its original length, the corresponding integrated pCOHP (IpCOHP) values are \u0026minus;\u0026thinsp;9.49, \u0026minus;\u0026thinsp;8.88, \u0026minus;\u0026thinsp;8.31, \u0026minus;\u0026thinsp;7.79, and \u0026minus;\u0026thinsp;7.33 eV, respectively. The value of IpCOHP becomes less negative as the C\u0026ndash;O bond elongates, indicating an increase in the antibonding state of the C\u0026ndash;O bond, resulting in the significant activation C\u0026ndash;O bond of the *CH\u0026ndash;COH intermediate (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec\u0026ndash;e). As the C\u0026ndash;O bond stretches, the electron density and covalent property of C\u0026ndash;O gradually decrease, as revealed by the ELF patterns (Supplementary Figs.\u0026nbsp;8\u0026ndash;9). AIMD results indicate that higher temperatures cause the more obvious stretching of the C\u0026ndash;O bond in *CH\u0026ndash;COH, resulting in decreased electron density and covalent property of the C\u0026ndash;O bond. This, in turn, favors the activation of the C\u0026ndash;O bond in *CH\u0026ndash;COH for hydrogenation to *C\u0026ndash;CH and subsequently to C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e. In summary, high temperatures promote the production of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e over C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eCO\u003c/b\u003e \u003csub\u003e \u003cb\u003e2\u003c/b\u003e \u003c/sub\u003e \u003cb\u003eRR at various temperatures.\u003c/b\u003e CO\u003csub\u003e2\u003c/sub\u003eRR experiments were carried out using a flow-cell reactor in 1 M KOH, with the temperature of the electrolyte being regulated by a temperature controller. The catalyst employed in the study was Cu-NR catalyst, predominantly oriented along the (111) crystal plane and existed in the Cu(0) state, consistent with the Cu(111) model used for thermotical calculations. Relevant characterizations, such as the X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) image, transmission electron microscope (TEM) image, X-ray Photoelectron Spectroscopy (XPS) spectra and X-ray absorption near edge structure (XANES) spectrum of the Cu electrode are presented in (Supplementary Figs.\u0026nbsp;10\u0026ndash;13). When temperatures are varied, significant variations in product distributions are observed, yet there is relatively small variation in total current density (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea\u0026ndash;c and Supplementary Fig.\u0026nbsp;14). For example, at \u0026minus;\u0026thinsp;1.3 V vs RHE, FE\u003csub\u003eC2+\u003c/sub\u003e increases from 73.6\u0026ndash;85.3% as the temperature drops from 40\u0026deg;C to \u0026minus;\u0026thinsp;3\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed). Notably, the increased FE\u003csub\u003eC2+\u003c/sub\u003e originates from the inhibited HER and enhanced C\u0026ndash;C coupling when decreasing temperature (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee\u0026ndash;f). Moreover, as the temperature decreases, the concentration of FE\u003csub\u003eC2H4\u003c/sub\u003e gradually diminishes, while that of FE\u003csub\u003eC2H5OH\u003c/sub\u003e evidently rises. Consequently, the FE\u003csub\u003eC2H4\u003c/sub\u003e/FE\u003csub\u003eC2H5OH\u003c/sub\u003e ratio exhibits a change from 1.86 to 0.98 when transitioning catholyte temperature from 40\u0026deg;C to \u0026minus;\u0026thinsp;3\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed), and the primary product of CO\u003csub\u003e2\u003c/sub\u003eRR shifts from C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e to C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH.\u003c/p\u003e \u003cp\u003eTo further investigate the relationship between temperature and CO\u003csub\u003e2\u003c/sub\u003eRR selectivity, we conducted experiments using different electrolytes and catalysts. Cu-NR electrode was employed for CO\u003csub\u003e2\u003c/sub\u003eRR in 3 M KOH across various temperatures. When decreasing the electrolyte temperature from 20\u0026deg;C to \u0026minus;\u0026thinsp;3\u0026deg;C, FE\u003csub\u003eC2+\u003c/sub\u003e value increases from 83.1\u0026ndash;90.1% over the Cu catalyst electrode at \u0026minus;\u0026thinsp;0.95 V vs RHE, with the FE\u003csub\u003eC2H4\u003c/sub\u003e/FE\u003csub\u003eC2H5OH\u003c/sub\u003e ratio varying from 1.44 to 0.96 (Supplementary Fig.\u0026nbsp;15a\u0026ndash;b). Additionally, commercial Cu nanoparticles (Cu-NP) with the dominant (111) crystal plane (Supplementary Figs.\u0026nbsp;10\u0026ndash;12) were used as catalysts for CO\u003csub\u003e2\u003c/sub\u003eRR across a temperature range of \u0026minus;\u0026thinsp;3\u0026deg;C to 20\u0026deg;C using 1 M KOH (Supplementary Fig.\u0026nbsp;15c\u0026ndash;d). A similar trend that lower temperatures favor C\u0026ndash;C coupling and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH formation is observed over Cu-NP electrode.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cb\u003eVariations of CO\u003c/b\u003e \u003csub\u003e \u003cb\u003e2\u003c/b\u003e \u003c/sub\u003e \u003cb\u003eRR intermediates at various temperatures.\u003c/b\u003e In situ ATR-SEIRAS spectra during CO\u003csub\u003e2\u003c/sub\u003eRR over Cu-NR electrode at varying temperatures and potentials were performed to investigate the influence of temperature on water structure and adsorbed intermediates. The OH stretching of water within the range of 3000\u0026thinsp;~\u0026thinsp;3800 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e can be divided into isolated water (~\u0026thinsp;3600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), weakly hydrogen-bonded water (~\u0026thinsp;3450 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and strongly hydrogen-bonded water (~\u0026thinsp;3250 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) after Gaussian fitting (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea\u0026ndash;c)\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. The proportion of isolated water decreases as the potential becomes increasingly negative, and this variation is more pronounced at lower temperatures (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed). The band center shift is negligible with potential at 40\u0026deg;C and 20\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea\u0026ndash;b). However, at \u0026minus;\u0026thinsp;3\u0026deg;C, the band center of OH stretching notably shifts to lower wavenumbers at more negative potentials (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec), indicating the formation of a robust hydrogen bond network. This strong hydrogen bond network at low temperature leads to reduced water activity, effectively suppressing HER. The peaks around 1210 and 1340 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e are identified as *OCCOH and *OCCHO, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef\u0026ndash;g), representing typical C\u0026ndash;C coupling intermediates\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. Additionally, the presence of the *OC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003e intermediate at 1330 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e suggests the formation of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. Comparatively, at \u0026minus;\u0026thinsp;3\u0026deg;C, the characteristic peaks corresponding to *OCCOH, *OCCHO, and *OC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003e shift to lower wavenumbers compared to those at 40\u0026deg;C, indicating increased adsorption of these intermediates. This suggests an enhancement in C\u0026ndash;C coupling and the C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH pathway at lower temperatures\u003csup\u003e\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn situ Raman peaks at approximately 360 and 1890/2060 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e are attributed to the frustrated rotation of Cu\u0026ndash;CO and C\u0026thinsp;\u0026equiv;\u0026thinsp;O stretching, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea\u0026ndash;b) \u003csup\u003e\u003cspan additionalcitationids=\"CR40\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. The peak at ~\u0026thinsp;700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is assigned to adsorbed *OH species, originating from H\u003csub\u003e2\u003c/sub\u003eO dissociation\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. Due to the Stark effect, these peaks exhibit blue shifts as the potential becomes more negative over the Cu-NR electrode, indicating a stronger Cu\u0026ndash;CO interaction\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. The Stark tuning slope of Cu\u0026ndash;CO increases as temperature varies from 40\u0026deg;C to \u0026minus;\u0026thinsp;3\u0026deg;C, suggesting that lower electrolyte temperature enhances CO adsorption on the electrode surface (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec). The CO stripping potential shifts to a higher value as the temperature decreases (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ef), providing further confirmation of the strengthened interaction between CO and the electrode surface, in accordance the DFT calculations (Supplementary Fig.\u0026nbsp;2) \u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe dependence of \u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2H4\u003c/sub\u003e and \u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2H5OH\u003c/sub\u003e on temperature is illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed. Both \u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2H4\u003c/sub\u003e and \u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2H5OH\u003c/sub\u003e exhibit positive correlations with temperature, with C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e production showing greater sensitivity to temperature changes (Supplementary Fig.\u0026nbsp;17). Since both C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH share the same *CH\u0026ndash;COH intermediate, decreasing the temperature evidently suppresses the formation of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e, leading to an increase in FE\u003csub\u003eC2H5OH\u003c/sub\u003e. The Tafel slopes for the production of C\u003csub\u003e2+\u003c/sub\u003e at 40\u0026deg;C, 20\u0026deg;C, and \u0026minus;\u0026thinsp;3\u0026deg;C are measured to be 114, 117, and 142 mV\u0026middot;dec\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ee), respectively. These values closely align with the theoretical value of 119 mV\u0026middot;dec\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, indicating that the rate-determining step is C\u0026ndash;C coupling at all investigated temperatures\u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e. The electrochemical double-layer capacitance (C\u003csub\u003edl\u003c/sub\u003e) values are 74.6, 44.7 and 25.9 mF\u0026middot;cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e at 40\u0026deg;C, 20\u0026deg;C, and \u0026minus;\u0026thinsp;3\u0026deg;C, respectively (Supplementary Fig.\u0026nbsp;18). The cations exhibit a tendency to migrate from electrolyte to the electrode surface at low temperature (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef), leading to the formation of a closely packed electrochemical double layer, consequently resulting in a decrease in the C\u003csub\u003edl\u003c/sub\u003e value at lower temperatures. The partial current density for C\u003csub\u003e2+\u003c/sub\u003e products (\u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2+\u003c/sub\u003e) was normalized on the basis of the electrochemically active surface area (ECSA), (Supplementary Fig.\u0026nbsp;19). A significantly higher \u003cem\u003ej\u003c/em\u003e\u003csub\u003eC2+\u003c/sub\u003e is observed at \u0026minus;\u0026thinsp;3\u0026deg;C, confirming that low temperature is indeed effective in promoting C\u0026ndash;C coupling.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, we have initiated an investigation for the influence of environmental temperature on CO\u003csub\u003e2\u003c/sub\u003eRR performance through theoretical calculations. As temperature decreases, *CO adsorption is favored while HER is inhibited, indicating a preference for C\u0026ndash;C coupling. The increased hydration of K\u003csup\u003e+\u003c/sup\u003e cations at low temperatures results in the reduced water activity, thereby inhibiting HER. The higher energy barrier for the hydrogenation of *CH\u0026ndash;COH to *CH\u0026ndash;C compared to *CH\u0026ndash;CHOH favors the C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH pathway at lower temperatures. In situ ATR-SEIRAS and Raman spectra, along with electrochemical characterizations, further confirm that *CO adsorption, water activity and the hydrogenation pathway of *CH\u0026ndash;COH intermediate are highly temperature-dependent, with C\u0026ndash;C coupling and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH formation being enhanced at lower temperature. Consequently, FE\u003csub\u003eC2+\u003c/sub\u003e achieves a high value of 90.1% at \u0026minus;\u0026thinsp;3\u0026deg;C over the Cu-NR electrode, with the main C\u003csub\u003e2+\u003c/sub\u003e product transitioning from C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e to C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH solely by decreasing the temperature. We believe this study will bring attention to the temperature effect on CO\u003csub\u003e2\u003c/sub\u003eRR as well as other electrocatalytic reactions, thereby paving the way for optimizing their efficiency.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e \u003cb\u003eDFT simulations.\u003c/b\u003e Density functional theory (DFT) method was used to perform all the spin-polarized calculations of these structures, as implemented in the Vienna ab initio simulation package code (VASP)\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. Exchange and correlation energies were described in the methods of generalized gradient approximation (GGA) in the form proposed by Perdew\u0026ndash;Burke\u0026ndash;Ernzerhof (PBE) functional\u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e. The projector-augmented wave (PAW) method was used to describe interaction between valance and core electrons\u003csup\u003e\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. The plane wave energy cutoff was set to be 500 eV. The structure optimization was relaxed until convergence criteria were met with the energy and force of 1\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e eV and 0.02 eV/\u0026Aring;, respectively. For structure optimizations, the first Brillouin-zone of such a slab sampled with the Monkhorst\u0026thinsp;\u0026minus;\u0026thinsp;Pack mesh with 3\u0026times;3\u0026times;1 grids, were used. To obtain more accurate electronic properties, a denser 7\u0026times;7\u0026times;1 k-point grids were further employed\u003csup\u003e\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e. The weak dispersion interaction was described by the DFT-D3 method with the standard parameters proposed by Grimme and his coworkers\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. To avoid interactions between two neighboring catalyst monolayers under periodic boundary conditions, a minimum vacuum space of 15 \u0026Aring; was set. Solvent effects were included by using implicit solvent model implemented by VASPsol with a dielectric constant of 80\u003csup\u003e52\u003c/sup\u003e. To confirm the bonding nature of the investigated systems by characterizing covalent bond, the electron localization function (ELF) and Critic2 were further employed\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e. The Crystal Occupation Hamiltonian Population (COHP) method was also employed to investigate the nature of bonding and anti-bonding states, as implemented by LOBSTER code\u003csup\u003e\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eSearching transition states (TS) were performed by employing improved dimer method implemented in Henkelman\u0026rsquo;s scripts, where the convergence force was set to be smaller than 0.02 eV/\u0026Aring;\u003csup\u003e57\u0026ndash;58\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eAb initio molecular dynamics (AIMD) simulations were performed with the Nose-Hoover thermostat approach, at the average temperature of \u0026minus;\u0026thinsp;40, 0 and 40\u0026deg;C, respectively\u003csup\u003e\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e. The time step in AIMD was set to be 1 fs. For AIMD simulations, a gamma-centered 1\u0026times;1\u0026times;1 k-point grid was used. We carried out 10 ps of AIMD simulation to obtain a well-equilibrated system.\u003c/p\u003e \u003cp\u003eTo simulate the copper electrode surface, a three-layer and 4\u0026times;4 periodic cell Cu(111) slab was built, in which two bottom layers were fixed and the top layer was allowed to relax. To simulate the real solution environment, aqueous interface models for kinetic calculations contain 33 explicit water molecules, which could maintain the average water density in the bulk regions being around 1.0 g\u0026middot;cm\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e. One K atom was located in bulk water as a solvated K\u003csup\u003e+\u003c/sup\u003e in the solution, and a OH group was also located in bulk water to maintain the electrical neutrality of the periodic system.\u003c/p\u003e \u003cp\u003e \u003cb\u003eMD simulations.\u003c/b\u003e MD simulations were performed using xTB package\u003csup\u003e\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e\u003c/sup\u003e. The calculated density of this simulated system was about 1.0 g\u0026middot;cm\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e, closed to realistic solution circumstances. The MD simulation duration was 20 ps, ensuring that the solution system could reach a stable state, as shown in energy variation diagram (Supplementary Figs.\u0026nbsp;4\u0026ndash;5). The simulations were carried out in the constant particle number, volume and temperature (NVT) ensemble with the thermostat set to a constant temperature of \u0026minus;\u0026thinsp;40, 0 and 40\u0026deg;C, respectively. After the equilibration period of 10 ps, the snapshots were taken at every 50 fs intervals from the simulation trajectories to analyze distribution of free CO/OH\u003csup\u003e\u0026minus;\u003c/sup\u003e and CO/OH\u003csup\u003e\u0026minus;\u003c/sup\u003e adsorbed on catalyst surface.\u003c/p\u003e \u003cp\u003e \u003cb\u003eThermochemistry.\u003c/b\u003e The Gibbs free energy difference (∆G) between two neighboring intermediates, named 1 and 2, can be calculated by:\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:{\\varDelta\\:\\text{G}}_{21}={\\text{G}}_{2}-{\\text{G}}_{1}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eFor example, in the reaction *CO\u003csub\u003e2\u003c/sub\u003e\u0026rarr;*HOCO, where \u0026lsquo;*\u0026rsquo; indicates an adsorption site on the catalyst, ΔG was calculated based on the following equation:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\varDelta\\:\\text{G}=\\text{G}\\left(\\text{*}\\text{H}\\text{O}\\text{C}\\text{O}\\right)-\\text{G}\\left(\\text{*}{\\text{C}\\text{O}}_{2}\\right)-\\text{G}\\left({\\text{H}}^{+}/{\\text{e}}^{-}\\right)\\:\\left(2\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eFor this equation, the chemical potential of the H\u003csup\u003e+\u003c/sup\u003e/e\u003csup\u003e\u0026minus;\u003c/sup\u003e pair equals to the half value of the chemical potential of the dihydrogen molecule. Given the standard hydrogen electrode conditions, the G(H\u003csup\u003e+\u003c/sup\u003e/e\u003csup\u003e\u0026minus;\u003c/sup\u003e) equals to 1/2G(H\u003csub\u003e2\u003c/sub\u003e).\u003c/p\u003e \u003cp\u003eThe Gibbs free energy of intermediates can be calculated by employing the computational hydrogen electrode (CHE) model proposed by N\u0026oslash;rskov \u003cem\u003eet al\u003c/em\u003e. According to the CHE model, the Gibbs free energy of intermediates can be obtained as following Equation:\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$\\:G=E+ZPE-TS\\:\\left(3\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eAdsorbed intermediates were only taken vibrational entropy (S) into account, and the corresponding function is showed in the (4) formula.\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e\n$$\\:\\text{S}=-\\text{R}\\sum\\:_{\\text{i}}\\text{ln}\\left(1-{\\text{e}}^{\\raisebox{1ex}{${-\\text{h}\\text{v}}_{\\text{i}}$}\\!\\left/\\:\\!\\raisebox{-1ex}{$\\text{k}\\text{T}$}\\right.}\\right)+\\text{R}\\sum\\:_{\\text{i}}\\frac{{\\text{h}\\text{v}}_{\\text{i}}}{\\text{k}\\text{T}}\\frac{{\\text{e}}^{\\raisebox{1ex}{${-\\text{h}\\text{v}}_{\\text{i}}$}\\!\\left/\\:\\!\\raisebox{-1ex}{$\\text{k}\\text{T}$}\\right.}}{\\left(1-{\\text{e}}^{\\raisebox{1ex}{${-\\text{h}\\text{v}}_{\\text{i}}$}\\!\\left/\\:\\!\\raisebox{-1ex}{$\\text{k}\\text{T}$}\\right.}\\right)}\\:\\:\\left(4\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eIn the equation, R\u0026thinsp;=\u0026thinsp;8.314 J\u0026middot;mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003eK\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, k\u003csub\u003eB\u003c/sub\u003e=1.38\u0026middot;10\u003csup\u003e\u0026minus;\u0026thinsp;23\u003c/sup\u003e J\u0026middot;K\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, h\u0026thinsp;=\u0026thinsp;6.63\u0026middot;10\u003csup\u003e\u0026minus;\u0026thinsp;34\u003c/sup\u003e J\u0026middot;s, T\u0026thinsp;=\u0026thinsp;298.15 K; i is the frequency number; ν\u003csub\u003ei\u003c/sub\u003e is the vibrational frequency.\u003c/p\u003e \u003cp\u003eUnder normal conditions, the values of entropy of free gas molecules in the system should be obtained from NIST database. However, values of entropy of free gas molecules of NIST database is only appropriate for above 0 ℃. Therefore, for our systems, all the values of entropy of free gas molecules and adsorbed gas molecules were obtained from vibration frequency calculation.\u003c/p\u003e \u003cp\u003eThe adsorption free energies of *CO\u003csub\u003e2\u003c/sub\u003e and *H on the pure copper surfaces are defined as\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e\n$$\\:\\varDelta\\:{\\text{G}}_{\\text{a}\\text{d}}\\left({\\text{C}\\text{O}}_{2}\\right)=\\text{G}\\left(\\text{*}{\\text{C}\\text{O}}_{2}\\right)-\\text{G}\\left(\\text{*}\\right)-\\text{G}\\left({\\text{C}\\text{O}}_{2}\\right)\\:\\left(5\\right)$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Eque\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Eque\" name=\"EquationSource\"\u003e\n$$\\:\\varDelta\\:{\\text{G}}_{\\text{a}\\text{d}}\\left(\\text{H}\\right)=\\text{G}\\left(*\\text{H}\\right)-\\text{G}\\left(\\text{*}\\right)-\\raisebox{1ex}{$1$}\\!\\left/\\:\\!\\raisebox{-1ex}{$2$}\\right.\\text{G}\\left({\\text{H}}_{2}\\right)\\:\\left(6\\right)$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003e \u003cb\u003eChemicals.\u003c/b\u003e CuSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;5H\u003csub\u003e2\u003c/sub\u003eO (99.99% metals basis) and C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003eNa\u003csub\u003e3\u003c/sub\u003e\u0026middot;2H\u003csub\u003e2\u003c/sub\u003eO (A. R. grade) were purchased from Aladdin. KOH (A. R. grade), NaOH (A. R. grade), acetone (A. R. grade) and ethanol (A. R. grade) were provided by Sinopharm Chemical Reagent Co., Ltd, China. Cu-NP was purchased from Simga-Aldrich. D\u003csub\u003e2\u003c/sub\u003eO (99.9%), gas diffusion electrode (YLS-30) with 10% PTFE and microporous layer, anion exchange membrane (FAA-3-PK-130) and Nickel foil (purity\u0026thinsp;\u0026gt;\u0026thinsp;99.8%, thickness 0.5 mm) were obtained from Alfa Aesar China Co., Ltd. Both CO\u003csub\u003e2\u003c/sub\u003e and Ar (Beijing Beiwen Gas Chemical Industry Co., Ltd., research grade) has purities of 99.999% and used as received. Aqueous solutions were prepared with deionized water (Millipore 18.2 MΩ cm).\u003c/p\u003e \u003cp\u003e \u003cb\u003ePreparation of the Cu-NR electrode\u003c/b\u003e. Initially, 1.3 mmol of CuSO\u003csub\u003e4\u003c/sub\u003e\u0026middot;5H\u003csub\u003e2\u003c/sub\u003eO and 0.91 mmol of C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003eNa\u003csub\u003e3\u003c/sub\u003e\u0026middot;2H\u003csub\u003e2\u003c/sub\u003eO were dissolved into the 40 mL of deionized water with stirring for 15 min at room temperature. 5.3 mmol of NaOH was then added into the mixture and further stirred for 2.5 h. The resultant solution was transferred to autoclave and kept at 160\u0026deg;C for 12 h. When the hydrothermal procedure was finished, the obtained product was washed with deionized water and absolute ethanol for three times, alternately. The obtained product was dried at 60\u0026deg;C for 8 h and then annealed at 400\u0026deg;C for 4 h in air\u003csup\u003e\u003cspan citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e\u003c/sup\u003e. Subsequently, 10 mg of the as-prepared material and 10 \u0026micro;L of Nafion solution (5 wt %) were added into 1 mL of isopropanol and sonicated for 30 min. The as-prepared ink was then drop-coated on the polytetrafluoroethylene (PTFE)-hydrophobized carbon fiber paper (Toray, YLS-30T GDL) and dried. Finally, the as-prepared electrodes underwent electroreduction in 1 M KOH at -0.5 V vs RHE for 10 minutes, resulting in the formation of Cu-NR electrode.\u003c/p\u003e \u003cp\u003e \u003cb\u003eMaterial characterizations\u003c/b\u003e. The morphology was characterized by SEM TESCAN MIRA LMS and TEM Thermo Fisher Talos F200S G2. XRD was conducted using an X-ray diffractometer (PANalytical Empyrean) with a scan speed of 5\u003csup\u003eo\u003c/sup\u003e\u0026middot;min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. XPS analysis was conducted on the Thermo Scientific ESCALab 250Xi (USA) using 200 W monochromatic Al Kα radiation. XANES data were collected at 1W2B station in Beijing Synchrotron Radiation Facility (BSRF) operated at 2.5 GeV with a maximum current of 250 mA.\u003c/p\u003e \u003cp\u003e \u003cb\u003eCO\u003c/b\u003e \u003csub\u003e \u003cb\u003e2\u003c/b\u003e \u003c/sub\u003e \u003cb\u003eRR experiments.\u003c/b\u003e CO\u003csub\u003e2\u003c/sub\u003eRR experiments were conducted using a CHI-660e electrochemical workstation equipped with a high current amplifier CHI-680c in an electrochemical flow-cell consisted of a gas chamber, a cathodic chamber and an anodic chamber. The anion exchange membrane (FumasepFAA-3-PK-130) was used to separate the anodic and cathodic chambers, and a Hg/HgO electrode (1 M KOH electrolyte used as the filling solution) and Nickel foil were used as the reference and counter electrodes, respectively. All potentials were converted to the RHE reference scale using the relation: E\u003csub\u003eRHE\u003c/sub\u003e=E\u003csub\u003eHg/HgO\u003c/sub\u003e+0.098\u0026thinsp;+\u0026thinsp;0.059\u0026times;pH. In the electrochemical CO\u003csub\u003e2\u003c/sub\u003eRR performance tests, KOH was used as the electrolyte, and the electrolyte was circulated through the cathodic and anodic chambers using peristaltic pumps at a rate of 30 mL\u0026middot;min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The flow rate of CO\u003csub\u003e2\u003c/sub\u003e gas through the gas chamber was controlled to be 30 sccm using a digital gas flow controller. To control the temperature of electrolyte, the electrolyte was placed in refrigerant at different temperatures.\u003c/p\u003e \u003cp\u003eThe gaseous product in the electrochemical experiment was collected into a gas bag and analyzed by gas chromatography (GC, HP 4890D). The liquid products were quantified using nuclear magnetic resonance spectroscopy (\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003eH NMR). \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003eH NMR spectra of freshly acquired samples were collected on a Bruker Avance III 400 HD spectrometer. Dimethyl sulfoxide (DMSO) was used as internal standard.\u003c/p\u003e \u003cp\u003eThe Faradaic efficiency (FE) of a product can be calculated by:\u003cdiv id=\"Equf\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equf\" name=\"EquationSource\"\u003e\n$$\\:\\text{F}\\text{E}=\\frac{\\text{n}}{\\raisebox{1ex}{$\\text{Q}$}\\!\\left/\\:\\!\\raisebox{-1ex}{$\\text{N}\\text{F}$}\\right.}\\times\\:100\\text{%}（1）$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere Q is charge (C), F is Faradaic constant (96485 C\u0026middot;mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), N is the number of transferred electrons to generate desired products, n is the moles of products. For the H\u003csub\u003e2\u003c/sub\u003e, CO, CH\u003csub\u003e4\u003c/sub\u003e, C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e, HCOOH, CH\u003csub\u003e3\u003c/sub\u003eOH, CH\u003csub\u003e3\u003c/sub\u003eCOOH, CH\u003csub\u003e3\u003c/sub\u003eCH\u003csub\u003e2\u003c/sub\u003eOH and n-C\u003csub\u003e3\u003c/sub\u003eH\u003csub\u003e7\u003c/sub\u003eOH, the N is 2, 2, 8, 12, 2, 6, 8, 12 and 18, respectively.\u003c/p\u003e \u003cp\u003e \u003cb\u003eElectrochemical tests.\u003c/b\u003e The variation in the partial current density vs applied potential was obtained via stepped potential electrolysis, and Tafel plots were generated from these data. C\u003csub\u003edl\u003c/sub\u003e was measured by the capacitive current associated with double-layer charging from the scan-rate dependence of cyclic voltammogram (CV). The CV tests were performed in a flow-cell with three electrodes, ranging from 0.25 V to 0.15 V vs RHE. 1 M KOH solution was used as the electrolyte. The scan rates were 10, 20, 30, 40, 60, 80, 100 and 120 mV\u0026middot;s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eCO stripping experiments were carried out using 0.1 M KHCO\u003csub\u003e3\u003c/sub\u003e as the electrolyte in an H-type cell. Prior to the experiment, all catalyst was electrolyzed at \u0026minus;\u0026thinsp;0.6 V vs RHE for 5 min to fully remove the oxidation species in 0.1 M Ar-saturated KHCO\u003csub\u003e3\u003c/sub\u003e. CO was then introduced into the cell and electrolyzed at \u0026minus;\u0026thinsp;0.8 V vs RHE for 10 min to obtain CO adsorption at the cathode. Ar was then flowed into the electrolyte to remove residual CO. CV curves were then conducted at a scan rate of 50 mV\u0026middot;s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003e \u003cb\u003eIn situ characterizations.\u003c/b\u003e In situ ATR-SEIRAS experiments were conducted in a modified electrochemical cell that integrated into a BRUKER VERTEX 70v spectrometer cooled by liquid nitrogen. The catalyst was spread on gold-plated silicon prism. A Pt electrode and an Ag/AgCl electrode were used as counter and reference electrodes, respectively. The 1 M KHCO\u003csub\u003e3\u003c/sub\u003e aqueous solution was used as electrolyte at various temperatures.\u003c/p\u003e \u003cp\u003eIn situ Raman experiments were conducted in a flow-cell equipped with a quartz window provided by GaossUnion (Tianjin) Photoelectric Technology Company, utilizing a Horiba LabRAM HR Evolution Raman microscope. A 533 nm excitation laser was used and signals were recorded using a 30 s integration and by averaging two scans. The Cu-NR electrode was used as working electrode. A graphite electrode and a Hg/HgO electrode were used as counter and reference electrodes, respectively. The anion exchange membrane was used to separate counter electrode and working electrode. The circulated 1 M KOH aqueous solution was used as electrolyte at various temperatures.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eAuthor Information\u003c/h2\u003e \u003cp\u003eCorrespondence and requests for materials should be addressed to X.K. ([email protected]) or B.H. ([email protected]).\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contributions\u003c/h2\u003e \u003cp\u003eS.L.: DFT calculations and MD simulation. S.L., Y.Y., J.Y.: syntheses and characterizations of catalysts. S.L., W.Z., M.Z. and H.Q.: CO\u003csub\u003e2\u003c/sub\u003eRR experiments and electrochemical characterizations. Y.W., H.W. and X.T.: In situ ATR-SEIRAS and Raman experiments. J.J.: analysis of XAS data. Y.X., X.S., Q.Z. and M. F.: mechanism analysis. X.K. and B.H.: overall design and direction of the project. S.L., X.K. and B.H.: preparation of the manuscript with help from all authors.\u003c/p\u003e\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eThe work was supported by the National Natural Science Foundation of China (22273108, 22293015, 22121002), Beijing Natural Science Foundation (2222043), CAS Project for Young Scientists in Basic Research (YSBR-050) and Innovation Program of the IHEP (2023000034), Photon Science Center for Carbon Neutrality. The X-ray absorption spectroscopy measurements were performed at Beijing Synchrotron Radiation Facility (BSRF).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFan M et al (2023) Cationic-group-functionalized electrocatalysts enable stable acidic CO\u003csub\u003e2\u003c/sub\u003e electrolysis. Nat Catal 6:763\u0026ndash;772\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDing J et al (2023) A tin-based tandem electrocatalyst for CO\u003csub\u003e2\u003c/sub\u003e reduction to ethanol with 80% selectivity. Nat Energy 8:1386\u0026ndash;1394\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang P, Gao M (2023) Enrichment of reactants and intermediates for electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction. Chem Soc Rev 52:4343\u0026ndash;4380\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang G et al (2021) Electrocatalysis for CO\u003csub\u003e2\u003c/sub\u003e conversion: From fundamentals to value-added products. Chem Soc Rev 50:4993\u0026ndash;5061\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa W et al (2021) Electrocatalytic reduction of CO\u003csub\u003e2\u003c/sub\u003e and CO to multi-carbon compounds over Cu-based catalysts. Chem Soc Rev 50:12897\u0026ndash;12914\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMa Z et al (2022) CO\u003csub\u003e2\u003c/sub\u003e electroreduction to multicarbon products in strongly acidic electrolyte via synergistically modulating the local microenvironment. Nat Commun 13:7596\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiao J et al (2024) Steering the reaction pathway of CO\u003csub\u003e2\u003c/sub\u003e electroreduction by tuning the coordination number of copper catalysts. J Am Chem Soc 146:15917\u0026ndash;15925\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu X et al (2024) Coverage enhancement accelerates acidic CO\u003csub\u003e2\u003c/sub\u003e electrolysis at ampere-level current with high energy and carbon efficiencies. Nat Commun 15:1711\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZeng M et al (2024) Reaction environment regulation for electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction in acids. Angew Chem Int Ed 63:e202404574\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHe M et al (2022) Selective enhancement of methane formation in electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction enabled by a Raman-inactive oxygen-containing species on Cu. ACS Catal 12:6036\u0026ndash;6046\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTimoshenko J et al (2022) Steering the structure and selectivity of CO\u003csub\u003e2\u003c/sub\u003e electroreduction catalysts by potential pulses. Nat Catal 5:259\u0026ndash;267\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi C, Hansen HA, Lausche AC, N\u0026oslash;rskov JK (2014) Trends in electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction activity for open and close-packed metal surfaces. Phys Chem Chem Phys 16:4720\u0026ndash;4727\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y et al (2024) Strong hydrogen-bonded interfacial water inhibiting hydrogen evolution kinetics to promote electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction to C\u003csub\u003e2+\u003c/sub\u003e. ACS Catal 14:3457\u0026ndash;3465\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng J et al (2023) Improving CO\u003csub\u003e2\u003c/sub\u003e-to-C\u003csub\u003e2+\u003c/sub\u003e product electroreduction efficiency via atomic Lanthanide dopant-induced tensile-strained CuO\u003csub\u003ex\u003c/sub\u003e catalysts. J Am Chem Soc 145:9857\u0026ndash;9866\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGe W et al (2022) Dynamically formed surfactant assembly at the electrified electrode\u0026ndash;electrolyte interface boosting CO\u003csub\u003e2\u003c/sub\u003e electroreduction. J Am Chem Soc 144:6613\u0026ndash;6622\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeng T et al (2024) Polymer modification strategy to modulate reaction microenvironment for enhanced CO\u003csub\u003e2\u003c/sub\u003e electroreduction to ethylene. Angew Chem Int Ed 63:e202313796\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaneco S, Iiba K, Ohta K, Mizuno T, Saji A (1998) Electrochemical reduction of CO\u003csub\u003e2\u003c/sub\u003e on Au in KOH\u0026thinsp;+\u0026thinsp;methanol at low temperature. J Electroanal Chem 441:215\u0026ndash;220\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaneco S, Iiba K, Ohta K, Mizuno T, Saji A (1998) Electrochemical reduction of CO\u003csub\u003e2\u003c/sub\u003e at an Ag electrode in KOH-methanol at low temperature. Electrochim Acta 44:573\u0026ndash;578\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi K et al (2023) Superhydrophobicity-enabled efficient Electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e reduction at a high temperature. ACS Catal 13:9346\u0026ndash;9351\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOuyang Y et al (2023) Selectivity of electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction toward ethanol and ethylene: the key role of surface-active hydrogen. ACS Catal 13:15448\u0026ndash;15456\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng T, Xiao H, Goddard WA (2017) Full atomistic reaction mechanism with kinetics for CO reduction on Cu(100) from ab initio molecular dynamics free-energy calculations at 298 K. \u003cem\u003eProc. Natl. Acad. Sci. U.S.A.\u003c/em\u003e 114, 1795\u0026ndash;1800\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalle-Vallejo F, Koper MTM (2013) Theoretical considerations on the electroreduction of CO to C\u003csub\u003e2\u003c/sub\u003e species on Cu(100) electrodes. Angew Chem Int Ed 52:7282\u0026ndash;7285\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWan M et al (2023) Enhanced CO\u003csub\u003e2\u003c/sub\u003e reactive capture and conversion using aminothiolate ligand-metal interface. J Am Chem Soc 145:26038\u0026ndash;26051\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLin L et al (2021) Temperature-dependent CO\u003csub\u003e2\u003c/sub\u003e electroreduction over Fe-N-C and Ni-N-C single-atom catalysts. Angew Chem Int Ed 60:26582\u0026ndash;26586\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVos RE et al (2023) How temperature affects the selectivity of the electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction on copper. ACS Catal 13:8080\u0026ndash;8091\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJo SW, Kim JY, Lee MW, Kim Y, Ahn HS (2023) Highly selective reduction of CO\u003csub\u003e2\u003c/sub\u003e to methane induced by subzero depression of the electrode surface temperature. ACS Catal 13:5122\u0026ndash;5126\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVos RE, Koper MTM (2022) The effect of temperature on the cation-promoted electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction on gold. ChemElectroChem 9, e202200239\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhn ST, Abu-Baker I, Palmore GTR (2017) Electroreduction of CO\u003csub\u003e2\u003c/sub\u003e on polycrystalline copper: Effect of temperature on product selectivity. Catal Today 288:24\u0026ndash;29\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVavra J et al (2024) Solution-based Cu\u003csup\u003e+\u003c/sup\u003e transient species mediate the reconstruction of copper electrocatalysts for CO\u003csub\u003e2\u003c/sub\u003e reduction. Nat Catal 7:89\u0026ndash;97\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao Q, Martirez JMP, Carter EA (2021) Revisiting understanding of electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction on Cu(111): Competing proton-coupled electron transfer reaction mechanisms revealed by embedded correlated wavefunction theory. J Am Chem Soc 143:6152\u0026ndash;6164\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZheng M et al (2022) Electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e-to-C\u003csub\u003e2+\u003c/sub\u003e with ampere-level current on heteroatom-engineered copper via tuning *CO intermediate coverage. J Am Chem Soc 144:14936\u0026ndash;14944\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXie Y et al (2022) High carbon utilization in CO\u003csub\u003e2\u003c/sub\u003e reduction to multi-carbon products in acidic media. Nat Catal 5:564\u0026ndash;570\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang X et al (2024) Cation-induced interfacial hydrophobic microenvironment promotes the C\u0026ndash;C coupling in electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction. J Am Chem Soc 146:5532\u0026ndash;5542\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGorthy S et al (2023) Theoretical insights into the effects of KOH concentration and the role of OH\u003csup\u003e\u0026ndash;\u003c/sup\u003e in the electrocatalytic reduction of CO\u003csub\u003e2\u003c/sub\u003e on Au. ACS Catal 13:12924\u0026ndash;12940\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchaefer J, Backus EHG, Nagata Y, Bonn M (2016) Both inter- and intramolecular coupling of O\u0026ndash;H groups determine the vibrational response of the water/air interface. J Phys Chem Lett 7:4591\u0026ndash;4595\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang P et al (2022) Boosting electrocatalytic CO\u003csub\u003e2\u003c/sub\u003e-to-ethanol production via asymmetric C-C coupling. Nat Commun 13:3754\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun W et al (2022) V-Doped Cu\u003csub\u003e2\u003c/sub\u003eSe hierarchical nanotubes enabling flow-cell CO\u003csub\u003e2\u003c/sub\u003e electroreduction to ethanol with high efficiency and selectivity. Angew Chem Int Ed 34:2207691\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu Z et al (2022) Identification of Cu(100)/Cu(111) interfaces as superior active sites for CO dimerization during CO\u003csub\u003e2\u003c/sub\u003e electroreduction. J Am Chem Soc 144:259\u0026ndash;269\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNguyen TN et al (2022) Catalyst regeneration via chemical oxidation enables long-term electrochemical carbon dioxide reduction. J Am Chem Soc 144:13254\u0026ndash;13265\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCao Y et al (2023) Surface hydroxide promotes CO\u003csub\u003e2\u003c/sub\u003e electrolysis to ethylene in acidic conditions. Nat Commun 14:2387\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmirbeigiarab R et al (2023) Atomic-scale surface restructuring of copper electrodes under CO\u003csub\u003e2\u003c/sub\u003e electroreduction conditions. Nat Catal 6:837\u0026ndash;846\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi H, Wei P, Gao D, Wang G (2022) In situ Raman spectroscopy studies for electrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction over Cu catalysts. Curr Opin Green Sustain Chem 34:100589\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCui Y et al (2023) N\u003csub\u003ex\u003c/sub\u003eC-induced switching of methane and ethylene products\u0026rsquo; selectivity from CO\u003csub\u003e2\u003c/sub\u003e electroreduction over Cu catalyst. ACS Catal 13:11625\u0026ndash;11633\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWei Z et al (2019) Optimizing alkyne hydrogenation performance of Pd on carbon in situ decorated with oxygen-deficient TiO\u003csub\u003e2\u003c/sub\u003e by integrating the reaction and diffusion. ACS Catal 9:10656\u0026ndash;10667\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi J et al (2021) Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper. Nat Commun 12:3264\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKresse G, Furthm\u0026uuml;ller J (1996) Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput Mater Sci 6:15\u0026ndash;50\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerdew JP et al (1992) Atoms, molecules, solids, and surfaces: Applications of the generalized gradient approximation for exchange and correlation. Phys Rev B 46:6671\u0026ndash;6687\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePerdew JP, Wang Y (1992) Accurate and simple analytic representation of the electron-gas correlation energy. Phys Rev B 45:13244\u0026ndash;13249\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBl\u0026ouml;chl PE (1994) Projector augmented-wave method. Phys Rev B 50:17953\u0026ndash;17979\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMonkhorst HJ, Pack JD (1976) Special points for Brillouin-zone integrations. Phys Rev B 13:5188\u0026ndash;5192\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrimme S, Antony J, Ehrlich S, Krieg H (2010) A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J Chem Phys 132:154104\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMathew K, Sundararaman R, Letchworth-Weaver K, Arias TA, Hennig RG (2014) Implicit solvation model for density-functional study of nanocrystal surfaces and reaction pathways. J Chem Phys 140:084106\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSavin A, Nesper R, Wengert S, F\u0026auml;ssler TF (1997) ELF: The electron localization function. Angew Chem Int Ed 36:1808\u0026ndash;1832\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOtero-de-la-Roza A, Johnson ER, Lua\u0026ntilde;a V (2014) Critic2: A program for real-space analysis of quantum chemical interactions in solids. Comput Phys Commun 185:1007\u0026ndash;1018\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDronskowski R, Bloechl PE (1993) Crystal orbital Hamilton populations (COHP): Energy-resolved visualization of chemical bonding in solids based on density-functional calculations. J Phys Chem 97:8617\u0026ndash;8624\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNelson R et al (2020) Local orbital projections, atomic charges, and chemical-bonding analysis from projector-augmented-wave-based density-functional theory. J Comput Chem 41:1931\u0026ndash;1940\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHenkelman GA, Uberuaga BP, J\u0026oacute;nsson H (2000) A climbing image nudged elastic band method for finding saddle points and minimum energy paths. J Chem Phys 113:9901\u0026ndash;9904\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHenkelman G, J\u0026oacute;nsson H (1999) A dimer method for finding saddle points on high dimensional potential surfaces using only first derivatives. J Chem Phys 111:7010\u0026ndash;7022\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBussi G, Donadio D, Parrinello M (2007) Canonical sampling through velocity rescaling. J Chem Phys 126:014101\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNos\u0026eacute; S (1984) A unified formulation of the constant temperature molecular dynamics methods. J Chem Phys 81:511\u0026ndash;519\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBannwarth C et al (2021) Extended tight-binding quantum chemistry methods. WIREs Comput Mol Sci 11:e1493\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen X et al (2021) Room-temperature NO\u003csub\u003e2\u003c/sub\u003e sensing properties and mechanism of CuO nanorods with Au functionalization. Sens Actuat B-Chem 328:129070\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-4925085/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4925085/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eTemperature affects both the thermodynamics of intermediate adsorption and the kinetics of elementary reactions. Despite its extensive study in thermocatalysis, temperature effect is typically overlooked in electrocatalysis. This study investigates how electrolyte temperature influences CO\u003csub\u003e2\u003c/sub\u003e electroreduction over Cu catalysts. Theoretical calculations reveal the significant impact of temperature on *CO and *H intermediate adsorption thermodynamics, water microenvironment at the electrode surface, and the electron density and covalent property of the C\u0026ndash;O bond in the *CH\u0026ndash;COH intermediate, crucial for the reaction pathways. The theoretical calculations are strongly verified by experimental results over different Cu catalysts. Faradaic efficiency (FE) toward multicarbon (C\u003csub\u003e2+\u003c/sub\u003e) products is favored at low temperatures. Cu nanorod electrode could achieve a FE\u003csub\u003eC2+\u003c/sub\u003e value of 90.1% with a current density of ~\u0026thinsp;400 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e at \u0026minus;\u0026thinsp;3\u0026deg;C. FE\u003csub\u003eC2H4\u003c/sub\u003e and FE\u003csub\u003eC2H5OH\u003c/sub\u003e show opposite trends with decreasing temperature. The FE\u003csub\u003eC2H4\u003c/sub\u003e/FE\u003csub\u003eC2H5OH\u003c/sub\u003e ratio can decrease from 1.86 at 40\u0026deg;C to 0.98 at \u0026minus;\u0026thinsp;3\u0026deg;C.\u003c/p\u003e \u003cp\u003eIntroduction\u003c/p\u003e \u003cp\u003eElectrochemical CO\u003csub\u003e2\u003c/sub\u003e reduction reaction (CO\u003csub\u003e2\u003c/sub\u003eRR) into high-value products stands as one of the most promising strategies for mitigating CO\u003csub\u003e2\u003c/sub\u003e emissions through the utilization of renewable electricity\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. CO\u003csub\u003e2\u003c/sub\u003eRR is a complex process involving multiple reaction pathways that harvest a diverse array of chemical products\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. However, the simultaneous occurrence of various CO\u003csub\u003e2\u003c/sub\u003eRR routes alongside the hydrogen evolution reaction (HER) can diminish the selectivity toward desired products\u003csup\u003e\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. The adsorption behavior of carbonous intermediates and the intricate water microenvironment at the electrode surface are pivotal factors for influencing these reaction pathways, thereby dictating the distribution of products\u003csup\u003e\u003cspan additionalcitationids=\"CR10 CR11\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. By far, researchers have developed a wide range of electrode materials and electrolytes tailored to finely control intermediate adsorption and the water microenvironment on the electrode surface\u003csup\u003e\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. These advancements hold significant promise for steering the CO\u003csub\u003e2\u003c/sub\u003eRR pathway toward desired product with enhanced efficiency and selectivity.\u003c/p\u003e \u003cp\u003eThe adsorption or dispersion of intermediates, as well as the water microenvironment, are significantly influenced by temperature since they are thermodynamically controlled\u003csup\u003e\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. For instance, both C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e and C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH share the same precursor *CH\u0026ndash;COH, leading to their simultaneous production\u003csup\u003e\u003cspan additionalcitationids=\"CR21 CR22\" citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. The kinetics of their distinct reduction pathways can be influenced by temperature, offering a feasible means to control the ratio of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e to C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH. Hence, adjusting the temperature of the electrolyte to regulate both thermodynamic and kinetics processes emerges as a potent method for steering the CO\u003csub\u003e2\u003c/sub\u003eRR pathway. Consequently, a comprehensive investigation into the relationship between performance and temperature is crucial, providing invaluable insights and guiding significance for optimizing CO\u003csub\u003e2\u003c/sub\u003eRR performance\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eCO\u003csub\u003e2\u003c/sub\u003eRR experiments are typically conducted at room temperature, which can vary, for example from \u0026minus;\u0026thinsp;3\u0026deg;C to 40\u0026deg;C, depending on seasons and regions. The environmental temperature, typically indicated by the electrolyte temperature, can significantly influence the performance of CO\u003csub\u003e2\u003c/sub\u003eRR, yet it is often ignored in CO\u003csub\u003e2\u003c/sub\u003eRR studies\u003csup\u003e\u003cspan additionalcitationids=\"CR26 CR27\" citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. In this study, we systematically investigated the impact of temperature on CO\u003csub\u003e2\u003c/sub\u003eRR performance. We initiated our study with theoretical calculations, including density functional theory (DFT) and molecular dynamics (MD) simulations, to explore the impact of temperature on intermediate adsorption and kinetics of elementary reactions in CO\u003csub\u003e2\u003c/sub\u003eRR. Subsequently, Cu catalysts were synthesized and employed for CO\u003csub\u003e2\u003c/sub\u003eRR at various temperatures. The theoretical findings aligned well with experimental observations, indicating that lower temperatures favor C\u003csub\u003e2+\u003c/sub\u003e production and promote the formation of C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH over C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e4\u003c/sub\u003e. For instance, a Faradaic efficiency toward multicarbon products (FE\u003csub\u003eC2+\u003c/sub\u003e) of 90.1% was achieved with a current density of ~\u0026thinsp;400 mA cm\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e at \u0026minus;\u0026thinsp;1.3 V vs RHE over a Cu nanorod (Cu-NR) electrode at \u0026minus;\u0026thinsp;3\u0026deg;C. Moreover, the FE\u003csub\u003eC2H4\u003c/sub\u003e/FE\u003csub\u003eC2H5OH\u003c/sub\u003e ratio decreases gradually from 1.86 to 0.98 in 1 M KOH as the temperature decreases from 40\u0026deg;C to \u0026minus;\u0026thinsp;3\u0026deg;C. Further characterizations, including in situ surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), in situ Raman spectroscopy and electrochemical analysis, provide a comprehensive understanding of the temperature effect on CO\u003csub\u003e2\u003c/sub\u003eRR performance.\u003c/p\u003e","manuscriptTitle":"Temperature-Dependent Pathways in Carbon Dioxide Electroreduction","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-08-30 03:00:45","doi":"10.21203/rs.3.rs-4925085/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c2bfcadc-5d62-4518-a957-1767258b7e6b","owner":[],"postedDate":"August 30th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":36764760,"name":"Physical sciences/Chemistry/Catalysis/Electrocatalysis"},{"id":36764761,"name":"Physical sciences/Chemistry/Electrochemistry/Electrocatalysis"}],"tags":[],"updatedAt":"2024-10-11T03:05:20+00:00","versionOfRecord":[],"versionCreatedAt":"2024-08-30 03:00:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4925085","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4925085","identity":"rs-4925085","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}