{"paper_id":"0a7f34ec-12c2-4e5b-a0d9-572f248e48d3","body_text":"Enhancement of the catalytic activity of Pt nanoparticles toward methanol electro- oxidation using La-doped-Ta 2 O 5 /MWCNTs supporting materials | 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 Research Article Enhancement of the catalytic activity of Pt nanoparticles toward methanol electro- oxidation using La-doped-Ta 2 O 5 /MWCNTs supporting materials Bohua Wu, Xicheng Lu, Fengxiao Du, Yifan Liu, Xiaoqin Wang, Shanxin Xiong This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5052774/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract In this work, La-doped Ta 2 O 5 was synthesized as support for Pt nanoparticles by hydrothermal method. The prepared Pt/Ta 2 O 5 -La/MWCNTs catalysts were characterized by TEM, XRD and XPS. These characterization methods confirm that Pt nanoparticles were successfully supported on La-doped Ta 2 O 5 /MWCNTs. The TEM reveals that the catalyst particle size on the surface of multi-walled carbon nanotubes is mainly between 2 nm and 10 nm, with an average particle size of 4.8 nm. The further electrochemical characterizations including CV, show that Pt/Ta 2 O 5 -La/MWCNTs catalysts have larger electrochemical surface area, better electrocatalytic activity and higher stability towards the methanol oxidation reaction compared to the carbon supported Pt catalysts. The excellent electrocatalytic performance is mainly contributed to the smaller particle size and more uniform dispersion of Pt nanoparticles. This work demonstrated that Ta 2 O 5 -La/MWCNTs is a promising anode catalyst support for direct methanol fuel cells. Anodes Ta2O5 Lanthanum Pt Nanoparticles Composite materials Electrocatalysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 1. Introduction Currently, platinum-based catalysts remain the optimal choice for direct methanol fuel cell (DMFC) anode catalysts [ 1 ] . However, these catalysts are susceptible to poisoning and aging caused by intermediate carbon compounds such as CO ads during methanol oxidation [ 2 ] . The adsorption of CO ads onto the active site of the catalyst can easily occur, leading to the occupation of the catalytic unit and a significant reduction in catalytic activity. Additionally, the high cost associated with Pt-based catalysts is primarily attributed to their extensive use of platinum. So far, many researchers have studied enhanced Pt catalysts to improve the electrocatalytic activity and durability of electrodes in the alcohol oxidation process [ 3 – 6 ] . The results showed that the Pt catalyst modified with a metal oxide support significantly improved the methanol oxidation. For example, Song et al. [ 7 ] introduced ZrO 2 into Pt-based catalysts using the sol-gel method to create Pt/ZrO 2 /CNT catalysts. The promotional effect can be attributed to the bifunctional mechanism between Pt and zirconium dioxide. Zhang et al. [ 8 ] prepared a PANI-modified MoO 3 nanorod-supported Pt catalyst. The results showed that the Pt/PANI-MoO 3 catalyst, supported by PANI-modified molybdenum trioxide nanorods, exhibited higher catalytic activity than the Pt/PANI catalyst supported by PANI nanotubes. Tantalum pentoxide in metal oxides is famous for its excellent mechanical, thermal, optical, and electrical properties [ 9 ] . It has been widely used in the manufacture of structural ceramic devices, gas sensors, catalysts, and optoelectronic devices [ 10 – 13 ] . Its acid and alkali resistance and chemical stability are also excellent [ 14 ], [ 15 ] . Therefore, it is essential to introduce Ta 2 O 5 into the development and research of fuel cells. This introduction can enhance the catalyst's activity and improve its acid and alkali corrosion resistance and electrochemical performance. However, the application of pure tantalum pentoxide is hindered by its weak electronic conductivity [ 16 ],[ 17 ] and tendency to agglomerate [ 18 ] . In order to make tantalum pentoxide a better carrier for platinum based catalysts, many scientists have attempted to increase current density and increase active sites. The Ishihara team [ 19 ] has prepared C and N doped Ta 2 O 5 electrocatalyst and demonstrated the good ORR capability of the catalyst. Wu et al. [ 20 ] doped Ru into Ta 2 O 5 to support Pt catalyst to prepare Pt/Ru-Ta 2 O 5 catalyst, and its catalyst has good dispersion, improving the catalytic activity and stability. It is proved that element doping is a very effective method to improve the conductivity of tantalum pentoxide. In this work, Ta 2 O 5 doped with the rare metal lanthanum is deposited onto multi-walled carbon nanotubes to enhance the conductivity and electrochemical performance of Ta 2 O 5 . The preparation process is shown in Fig. 1 . Lanthanum doping may enhance the electronic conductivity of Ta 2 O 5 and increase the electrochemically active surface area, thereby improving the electrocatalytic activity associated with the charge transfer process. Lanthanum doping can also boost the dissociation of water and regulate the poisoning effect of intermediate CO. Lanthanum was loaded onto Ta 2 O 5 /MWCNTs using the hydrothermal method, and then Pt was loaded onto Ta 2 O 5 -La/MWCNTs using the sodium borohydride-ethylene glycol double reduction method. Finally, Pt/Ta 2 O 5 -La/MWCNTs catalysts with high catalytic activity and stability were synthesized, and the influence of different doping amounts of La on the catalytic activity of the catalyst was discussed. The physical structure is characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, field emission scanning electron microscopy, and X-ray diffraction. The electrochemically active surface area, electrocatalytic activity, rate-determining steps, and stability of the catalyst are determined by cyclic voltammetry and timing currents. 2. Experimental 2.1.Materials MWCNTs was were purchased from Nanjing Xianfeng Nanomaterial Science and Technology Co., Ltd. with a pore size of 20–60 nm. 98% analytical pure concentrated sulfuric acid and concentrated nitric acid purchased from Beijing Chemical plant. 5 wt% Nafion was purchased from Alfa Esha (Tianjin) Chemical Co., Ltd. Other chemicals were of analytical grade and used as received. 2.2. Preparation of Pt/Ta 2 O 5 -La/MWCNTs catalysts The acid functionalization of MWCNTs was conducted using a mixed acid solution comprising H 2 SO 4 and HNO 3 . Specifically, 5g carbon nanotubes were combined with 120 mL of a concentrated mixed acid solution, which consisted of 98 wt% H 2 SO 4 and 40 mL of concentrated nitric acid. This mixture was subsequently transferred to a 250 mL three-port flask, where it was subjected to condensation and reflux at a temperature of 60°C for a duration of 5 hours. Following the reaction, the mixture was allowed to cool naturally to room temperature, diluted tenfold with water, and allowed to precipitate for 12 hours. The supernatant was then decanted, and the precipitate was filtered using a membrane filter. The resulting precipitate was washed with distilled water until a pH of 7 was achieved, yielding the acid-functionalized MWCNTs.After drying at 60°C for 12 hours in a vacuum drying oven, the acid-functionalized MWCNTs were obtained and designated as MWCNTs-AO. A total of 100 mg of MWCNTs-AO was dispersed in 50 mL of anhydrous ethanol through ultrasonic agitation for 30 minutes. Following this, 169 µL of a TaCl 5 solution in n-butanol, with a concentration of 200 mg/mL, was added to the dispersion. The mixture underwent an additional 30 minutes of ultrasonic treatment and stirring until the complete evaporation of ethanol was achieved, resulting in the formation of Ta(OH) m (OC 2 H 5 ) n /MWCNTs. The resultant mixture was subsequently ground and transferred to a vacuum drying oven, where it was dried at 60°C for 8 hours. Finally, the material was subjected to calcination at 800°C for 180 minutes in a nitrogen atmosphere, with a heating rate of 10°C per minute, culminating in the preparation of the Ta 2 O 5 /MWCNTs. Pt nanoparticles were immobilized onto a Ta 2 O 5 /MWCNTs support utilizing a dual reduction methodology. A chloroplatinic acid solution was initially prepared, achieving a concentration of 7.532 mg Pt/mL. Subsequently, 80 mg of the Ta 2 O 5 /MWCNTs support was measured and introduced into 50 mL of ethylene glycol, followed by ultrasonic dispersion for a duration of 30 minutes. After this, 2.65 mL of H 2 PtCl 6 solution was incorporated and the mixture was stirred. During the stirring phase, the pH was adjusted to approximately 11 using a 1M NaOH solution. A rapid addition of 10 mL of a 24 mg/mL NaBH 4 solution was made to the mixture, which was then subjected to ultrasonic treatment for an additional 30 minutes. The reaction proceeded under reflux conditions at 120°C for 3 hours. Upon completion of the reaction, the solution was allowed to cool to room temperature and was subsequently centrifuged. The resultant precipitate was washed three times with both deionized water and anhydrous ethanol, followed by vacuum drying at 60°C for 12 hours to yield the desired Pt/Ta 2 O 5 /MWCNTs catalyst. The platinum loading was determined to be 20 wt%, while the Ta 2 O 5 loading was 17 wt%. La particles were deposited onto the Ta 2 O 5 /MWCNTs support via a hydrothermal method. A total of 100 mg of Ta 2 O 5 /MWCNTs was utilized as the carrier, to which a specified volume of 20 mL of La(NO 3 ) 3 solution was added and mixed using ultrasonic agitation for 30 minutes. The mixture was then transferred to a 45 mL PTFE-lined reactor and subjected to a temperature of 200°C for 240 minutes. Following centrifugation, the product was washed with water and ethanol multiple times, and subsequently dried in a vacuum oven at 60°C for 12 hours to produce La-doped Ta 2 O 5 /MWCNTs, designated as Ta 2 O 5 -La/MWCNTs. The mass fractions of lanthanum incorporated were 15%, 20%, 25%, and 30%. Furthermore, Pt nanoparticles were loaded onto the Ta 2 O 5 -La/MWCNTs support using a double reduction technique. The chloroplatinic acid solution was prepared in advance, maintaining a concentration of 7.532 mg Pt/mL. An amount of 80 mg of Ta 2 O 5 -La/MWCNTs was weighed and combined with 50 mL of ethylene glycol, followed by ultrasonic dispersion for 30 minutes. Subsequently, 2.65 mL of H 2 PtCl 6 solution was added, and the mixture was stirred while adjusting the pH to approximately 11 with 1M NaOH. A rapid addition of 10 mL of a 24 mg/mL NaBH 4 solution was made, and ultrasonic treatment continued for an additional 30 minutes. The condensation reflux reaction was then conducted at 120°C for 3 hours. After the reaction concluded, the solution was cooled to room temperature, centrifuged, and the final precipitate was washed three times with deionized water and anhydrous ethanol. The target catalyst, Pt/Ta 2 O 5 -La/MWCNTs, was obtained through vacuum drying at 60°C for 12 hours, with platinum loading at 20 wt% and Ta 2 O 5 loading at 17 wt%. 2.3. Preparation of working electrodes The electrocatalytic performance of Pt/Ta 2 O 5 -La/MWCNTs-15%, Pt/Ta 2 O 5 -La/MWCNTs-20%, Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 -La/MWCNTs-30%, catalysts was measured in a typical three electrode system performed on a CHI660D electrochemical workstation (Chenhua Instrument Company of Shanghai, China). Glassy carbon electrodes (GC, 5 mm in diameter) coated with the catalyst served as the working electrodes, with a platinum counter electrode and a saturated calomel electrode (SCE). The GC electrode was first polished in a slurry of 0.03 µm alumina on a polishing cloth and then cleaned by ultrasonication in an ethanol/water mixture (1:1, v/v). At the same time, 3 mg catalyst was dispersed in 3 mL deionized water by ultrasonic wave to prepare a catalyst ink. The surface of the GC electrode was covered with 30 µL of the catalyst ink and wait until the solvent has evaporated completely. Then 10 µL of 0.05 wt% Nafion ethanol solution was added drop by drop and wait until the solvent has evaporated completely. Electrochemical measurements, including the cyclic voltammetry (CV) and chronoamperometry (CA) were done with were performed on a CHI660E electrochemical workstation, utilizing a conventional three-electrode cell at room temperature. 0.5 M H 2 SO 4 and 1.0 M CH 3 OH were employed as electrolytes. The CO adsorption and oxidation experiments were carried out using cyclic voltammetry at 0.5 M H 2 SO 4 , and then the CO stripping peak was obtained at a scanning rate of 50 mV s − 1 . The CO oxidation peak is then integrated to calculate the electrochemically active surface area (ECSA) of the sample. 2.4. Material characterization The bonding structure of the catalyst was studied using XRD analysis, model Diffractomete-6000, produced by Shimadzu Corporation in Japan. The defects of the material were studied using Raman spectroscopy, using equipment from Renishaw, UK, model inVia Reflex. The microstructure, particle size, and dispersion of the Pt/Ta 2 O 5 -La/MWCNTs catalyst were characterized using a TEM. The transmission electron microscope model JEM-3010 produced by Japan Electronics Corporation was used. XPS test was employed to analyze the surface composition and oxidation state of the catalysts. XPS analysis was carried out by using the Brooke Company model AXIS Supra. Using a field emission scanning electron microscope produced by Japan Electronics Corporation, model JSM-7610F, the elemental composition and content on the surface of the material was analyzed. CO-stripping were used to determine ESA and MA of catalysts. 3. Results and Discussion 3. 1 Characterization of the morphology and structure of catalyst The crystal structures of MWCNTs, Ta 2 O 5 /MWCNTs, Ta 2 O 5 -La/MWCNTs, and Pt/Ta 2 O 5 -La/MWCNTs catalysts were characterized by XRD, as shown in Fig. 2 (a). According to the Debye-Scherrer formula (1), the particle size of the crystal can be calculated accordingly [ 21 ] : d = 0. 9λ/(βcosθ 111 ) (1) The scanning range was 10° to 80°, and the scanning speed is 2°/min. 2θ = 26.2° corresponds to the (0 0 2) crystal plane of C. 2θ = 22.9°, 28.29°, and 36.66° correspond to (0 0 1), (1 10 0), and (1 11 1) crystal planes (JCPDS No. 25–0922) of Ta 2 O 5 . 2θ = 46.1°, 52.1°, and 56.0° correspond to the crystal planes (1 1 0), (1 0 3), and (2 0 1) of La 2 O 3 (JCPDS No.05-0602). 2θ = 39.76° corresponds to the (1 1 1) crystal plane of Pt (JCPDS No.04-0802). It can be confirmed that Pt, La 2 O 3 , and Ta 2 O 5 have been successfully loaded onto multi-walled carbon nanotubes. According to the Debye-Scherrer formula, it can be calculated that the particle sizes of Pt, La 2 O 3 , and Ta 2 O 5 are 2.8 nm, 3.8 nm, and 4.9 nm, respectively [ 22 ] . By adding Ta 2 O 5 /MWCNTs, the lattice constants of Ta 2 O 5 (1 1 1) were calculated by fitting the Ta 2 O 5 (1 1 1) planes of Ta 2 O 5 -La/MWCNTs. The calculation results are shown in Table 1 . After La doping, the lattice parameters of Ta 2 O 5 have changed from 0.2406 nm to 0.2483 nm. The lattice parameters have increased in the direction of La 2 O 3 , indicating successful doping of La 2 O 3 into Ta 2 O 5 . Moreover, the half-peak width of Ta 2 O 5 increases, and the particle size decreases, demonstrating that doping effectively hinders the gradual agglomeration of Ta 2 O 5 caused by Ostwald ripening. Figure 2 (b) shows the XRD patterns of Pt/Ta 2 O 5 -La/MWCNTs catalysts with varying La doping levels. 2θ = 39.76° corresponds to the (1 1 1) crystal plane of each Pt catalyst. It can be seen from the figure that when the La doping amount of the catalyst reaches 25%, the peak intensity at Pt (1 1 1) becomes higher and sharper, indicating an improvement in the crystal form of platinum. Table 2 presents the particle size analysis of Pt supported on different La contents in Pt/Ta 2 O 5 -La/MWCNTs catalyst. According to the analysis, it was found that Pt/Ta 2 O 5 -La/MWCNTs-25% has the smallest particle size. Better catalyst crystal form and smaller particle size are conducive to improving the activity of methanol electrocatalytic oxidation. Table 1 Lattice parameter of Ta 2 O 5 /MWCNTs and Ta 2 O 5 -La/MWCNTs Ta 2 O 5 /MWCNTs Ta 2 O 5 -La/MWCNTs Lattice constant (nm) 0.2406 0.2483 2θ (1 11 1) 37.10 36.25 FWHM(degree) 1.170 1.898 Particle size (nm) 5.48 4.91 Table 2 The size of Pt with different La content Doping 2θ (°) FWHM (°) D (nm) 15% 39.76 2.5151 3.6 20% 39.76 2.6724 3.2 25% 39.76 2.8099 2.8 30% 39.76 2.5652 3.3 Raman spectroscopy was used to study the surface structure and defect degree of catalysts. Raman spectroscopy was used to characterize MWCNTs catalysts, Ta 2 O 5 /MWCNTs catalysts, Ta 2 O 5 -La/MWCNTs catalysts, and Pt/Ta 2 O 5 -La/MWCNTs catalysts, as shown in Fig. 3 . The peak at 1377 cm − 1 is the D´ peak, which is due to the double resonance effect in the disordered carbon system. The peak at 1573 cm − 1 is called the G peak, corresponding to the E 2g modulus of the ordered structure of graphite. The peak near 1605 cm − 1 is called the D' peak, and its presence corresponds to defects in the hexagonal graphite structure. Therefore, the relative strength ratio of I D /I G can be used to explore the structural purity of graphite materials [ 23 ] . The I D /I G values of MWCNTs, Ta 2 O 5 /MWCNTs, Ta 2 O 5 -La/MWCNTs, and Pt/Ta 2 O 5 -La/MWCNTs are 1.37, 1.19, 1.22, and 1.01, respectively. Among them, the I D /I G value of MWCNTs is the highest, which is caused by a large number of defects on the surface of functionalized multi-wall carbon nanotubes. With the formation of Ta 2 O 5 , La, and Pt nanoparticles, they are dispersed on the functionalized multi-wall carbon nanotubes, covering more defect sites on the surface of MWCNTs. As a result, the I D /I G value decreases, and the relative strength of the Pt/Ta 2 O 5 -La/MWCNTs catalyst is the lowest. The microstructure, particle size, and dispersion of the Pt/Ta 2 O 5 -La/MWCNTs catalyst were characterized using a TEM. Figure 4 illustrates the dispersion of catalyst nanoparticles on multi-walled carbon nanotubes. As depicted in the figure, the nanoparticles exhibit good dispersibility with minimal agglomeration and well-defined crystal boundaries, suggesting that the catalyst particles maintain a stable crystal structure without dissolution. Figure 4 (c) and Fig. 4 (d) are HRTEM images of the catalyst. Clear lattice stripes can be observed in Fig. 4 (c) and d, indicating the catalyst particles' good crystallinity. The distance between lattice stripes measures approximately 0.19 nm and 0.23 nm, corresponding to the lattice spacing of Pt (2 0 0) and (1 1 1) [ 24 ] planes, respectively. Figure 5 displays the histogram of the particle size distribution of 50 nanoparticles randomly selected on the catalyst surface. Through measurement and calculation, the catalyst particle size on the surface of multi-walled carbon nanotubes is mainly between 2 nm and 10 nm, with an average particle size of 4.8 nm. This average particle size aligns with the calculation derived from XRD. Generally, a smaller catalyst particle size will have a larger specific surface area, providing more active site. This can enhance the catalytic activity of the catalyst. XPS was used to study the elemental composition and the valence state of each element in the catalyst. Figure 5 shows the XPS spectrum of Pt/Ta 2 O 5 -La/MWCNT catalyst. Figure 5 (a) shows that Pt, Ta 2 O 5 , and La have been successfully loaded onto multi-walled carbon nanotubes in each La-doped catalyst. Figure 5 (b) shows the XPS spectrum of a Pt/Ta 2 O 5 -La/MWCNT catalyst with 25% La doping. After correction, it shows the presence of Pt, Ta 2 O 5 , La, and C. Figure 5 (c) displays the high-resolution C 1s XPS spectrum. The peaks centered at 284.8 eV and 286.3 eV in the figure can be attributed to the sp 2 hybrid C-C bond and C-O bond, respectively. The peak with a binding energy of 290. 0 eV can be attributed to O-C = O.As shown in Fig. 5 (d), the high-resolution Ta 4f XPS spectrum displays a pair of peaks at the binding energies of 28.4 eV and 26.4 eV, corresponding to the binding energy of Ta 5+ , which confirms the formation of Ta 2 O 5 . As shown in Fig. 5 (e), the high-resolution La 3d XPS spectrum displays a pair of peaks at binding energies of 852.6 eV and 834.8 eV, respectively, corresponding to the La 3+ binding energy, confirming the presence of La 2 O 3 [ 25 ] . As shown in Fig. 5 (f), the two peaks in the high-resolution Pt 4f XPS spectrum at the binding energies of 74.0 eV and 70.6 eV can correspond to the formation of Pt 0 , while the peaks at the binding energies of 75.4 eV, 72.0 eV and 77.9 eV, 74.5 eV correspond to PtO and the peaks at 77.9 eV and 74.5 eV correspond to PtO 2 , respectively. Compared with the standard binding energy of Ta 2 O 5 [ 26 ][ 27 ] , the binding energy of Pt/Ta 2 O 5 -La/MWCNTs catalyst Ta 4f shifted 0.3 eV in the positive direction. The binding energy of the electron at La 3d [ 28 ] shifted forward by 0.2 eV compared with the standard La 3+ binding energy. The electron binding energy at Pt 4f experienced a negative shift of 0.4 eV compared with the standard Pt 0 binding energy. It shows that there is a strong electron coupling effect between Pt, La, and Ta 2 O 5 . The electron transfer from Ta 2 O 5 [ 29 ] and La 2 O 3 to Pt promotes the formation of Pt 0 , thereby enhancing the utilization of platinum atoms in the catalyst. Table 3 Content of catalyst Pt/Ta 2 O 5 -La/MWCNTs Moore's share Quality as a percentage C 62.75 40.02 O 9.75 8.28 La 11.38 16.84 Ta 14.05 13.44 Pt 2.06 21.42 Table 3 shows the content of each element obtained by fitting the XPS peak value of Pt/Ta 2 O 5 -La/MWCNTs catalyst. The molar ratios of C, O, La, Ta and Pt are 62.75%, 9.75%, 11.38%, 14.05% and 2.06% respectively, and the mass ratios are 40.02%, 8.28%,16.84%, 13.44% and 21.42% respectively. Figure 6 displays the field emission scanning electron microscope and mapping scanning diagram of the Pt/Ta 2 O 5 -La/MWCNTs catalyst. Although the presence of catalyst nanoparticles is not obvious in the FESEM image, the smaller agglomeration can be used as an indicator of a well-distributed nanoparticles. Since the distribution of catalyst particles in FESEM images is not clear, we also conducted mapping analysis on Pt/Ta 2 O 5 -La/MWCNTs. The images related to different elements are shown in Fig. 6 . The elemental mapping confirmed the uniform distribution of Pt, La, and Ta 2 O 5 nanoparticles on the surface of MWCNTs through spectrum analysis. The element map in Fig. 6 (a) shows that the doping effect is ideal. As shown in Fig. 7 , the elemental composition of the Pt/Ta 2 O 5 -La/MWCNTs surface was studied through EDS analysis. It can be seen from the figure that the presence of peaks corresponding to Pt, La, and Ta 2 O 5 confirms the successful synthesis of Pt, La, and Ta 2 O 5 at the conclusion of the reaction. The mass ratio of catalysts C, Pt, O, La, and Ta is 48.4% : 15.0% : 8.7% : 11.7% : 16.2%, respectively. 3. 2 Characterization of electrocatalytic properties of catalysts Figure 8 displays the CV curve of the Pt/Ta 2 O 5 -La/MWCNTs catalyst with 15%, 20%, 25%, and 30% La doping in a 0.5 M H 2 SO 4 solution. The scanning rate is 50 mV s − 1 , and the scanning window ranges from − 0.25 V to 1 V. Typically, the hydrogen adsorption-desorption peak can be utilized to calculate the ESA value of the catalyst [ 30 ] . Through calculation, the ESA values of 15%, 20%, 25%, and 30% Pt/Ta 2 O 5 -La/MWCNTs catalysts are 34.2 m 2 g − 1 Pt , 51.3 m 2 g − 1 Pt , 65.0 m 2 g − 1 Pt and 48.5 m 2 g − 1 Pt , respectively. Pt/Ta 2 O 5 -La/MWCNTs 25% catalyst has the highest ESA value, indicating that when the La doping amount is 25%, it exhibits the highest catalytic potential and reaction activity. Therefore, it can be inferred that the catalytic activity of Pt/Ta 2 O 5 -La/MWCNTs 25% will be higher than that of other catalysts. Although the hydrogen adsorption-desorption peak of the Pt/Ta 2 O 5 -La/MWCNTs 30% catalyst is similar to that of the La-25% catalyst, the EAS value is low. This is attributed to the large nanoparticle size of the Pt/Ta 2 O 5 -La/MWCNTs-30% catalyst, as indicated by the XRD calculation results, resulting in a small electrochemical active surface area. In order to ensure the accuracy of the experimental results, we also conducted CO-stripping experiments to calculate ESA. The tolerance of a catalyst to CO is an essential parameter for evaluating its efficacy. This tolerance is generally quantified using a method known as dissolved CO-stripping. This procedure entails the continuous introduction of carbon monoxide gas into a 0.5 M H 2 SO 4 solution while maintaining a constant voltage to promote the adsorption of CO. It can be observed from the voltammograms that for the four catalysts in the first scan, the hydrogen desorption peaks are suppressed in the lower potential region due to the saturation of Pt surface with CO ad species. The CO absorption peaks of the four catalysts all appeared near 0.5V. No CO oxidation was monitored in the second scan for the four catalysts, which conforms the complete removal of CO ad species. Additionally, the ESA of the catalysts were calculated by integrating the peaks associated with CO oxidation, as outlined in Figure S4. Through calculation, the ESA values of 15%, 20%, 25%, and 30% Pt/Ta 2 O 5 -La/MWCNTs catalysts are 28.3 m 2 g − 1 Pt , 43.7 m 2 g − 1 Pt , 61.5 m 2 g − 1 Pt and 47.3 m 2 g − 1 Pt , the area current is 7.78A m − 2 , 9.78 A m − 2 , 9.99 A m − 2 , 8.04 A m − 2 , which are similar to the previous calculated values. The results show that 25% lanthanum doped catalyst has the best catalytic activity, followed by 20% and 30%, and finally 15%. The lower activity of Pt/Ta 2 O 5 -La/MWCNT-30% catalyst is due to the poor crystal structure of platinum, which prevents the enhancement of catalytic surface area and catalytic activity of the catalyst. In order to further explore the electrocatalytic methanol oxidation activity of Pt/Ta 2 O 5 -La/MWCNTs with 15%, 20%, 25%, and 30% La doping, CV tests were conducted in a mixed solution of 0.5 M H 2 SO 4 and 1.0 M CH 3 OH mixed solution with a sweep rate of 50 mV s − 1 and a potential window of 0 V to 1 V. Figure 9 illustrates that the Pt/Ta 2 O 5 -La/MWCNTs catalysts with varying La doping levels and Pt/MWCNTs can be utilized in the reaction of 0.5 M H 2 SO 4 + 1.0 M CH 3 OH CV curve in a mixed solution. As previously documented, these are all typical cyclic voltammetric curves of MOR. Moreover, the activity of the Pt/Ta 2 O 5 -La/MWCNTs 25% catalyst is up to 614.63 mA·mg − 1 Pt , which is higher than that of the La-15% (219.95 mA·mg − 1 Pt ), La-20% (426.92 mA·mg − 1 Pt ), La-30% (364.42 mA·mg − 1 Pt ) catalysts and Pt/MWCNTs (297.7 mA·mg − 1 Pt ). As depicted in the figure, the peak observed during forward scanning corresponds to the methanol oxidation activity, while the peak in reverse scanning represents the oxidation of methanol on the surface, which is associated with the removal of adsorbed CO and HCO species. It can be seen from the figure that the initial potentials of Pt/Ta 2 O 5 -La/MWCNTs catalysts with concentrations of 15%, 20%, 25%, and 30% are 0.49V, 0.48V, 0.42V, and 0.42V, respectively. The initial potential of the Pt/Ta 2 O 5 -La/MWCNTs 25% catalyst is lower than that of the other four catalysts including Pt/MWCNTs. This indicates that methanol is more likely to catalyze the reaction on the Pt/Ta 2 O 5 -La/MWCNTS-25% catalyst. Figure S3 shows the SA of the four prepared catalysts. According to Figure S3, the mass activity of Pt/Ta 2 O 5 -La/ MWCNT-25% catalyst was the highest, followed by 20%, 30% and 15%. Moreover, the electrocatalytic activities for all the catalysts were also evaluated using mass specific activity (MA) with respect to the peak potential for MOR.According to formula (2) [ 31 ] : $$\\:{M}_{A}\\:=\\:\\frac{{Q}_{H}}{{L}_{Pt}}$$ 2 Q H is the charge density for the methanol oxidation peak (mC cm − 2 ) and L is the loading of Pt in the electrode (mg cm − 2 ). Table 4 Methanol oxidation behavior of various electrocatalysts Catalyst Peak current potential (V vs. SCE) Peak current (mA mg Pt -1 ) References Pt/Ta 2 O 5 -La/MWCNTs 0.66 614.63 This work PtCu/MWCNTs 0.65 504.19 Reference [ 32 ] Pt 1 Gd 1 /Gd 2 O 3 0.65 425.67 Reference [ 33 ] PtNi/CNSs 0.75 393.02 Reference [ 34 ] After calculation, The MA of Pt/Ta 2 O 5 -La/MWCNTs-15%, Pt/Ta 2 O 5 -La/MWCNTs-20%, Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 -La/MWCNT-30% catalyst was 118.7 mC mg − 1 ,192.6 mC mg − 1 ,258.3 mC mg − 1 ,185.2 mC mg − 1 .The catalytic activity of Pt/MWCNTs catalysts was higher than that of 15% doped catalysts but lower than that of 20%, 25%, 30% doped catalysts. Similar to the ESA calculation results, the catalytic activity of the Pt/Ta 2 O 5 -La/MWCNTs 30% catalyst is also lower than that of the Pt/Ta 2 O 5 -La/MWCNTs 25% catalyst. As revealed by XRD analysis, the size of Pt/Ta 2 O 5 -La/MWCNTs-30% catalyst nanoparticles is larger, and the peak intensity and sharpness at Pt (1 1 1) are low. This indicates that the crystal structure of platinum is poor, which hinders the enhancement of the catalytic surface area and catalytic activity of the catalyst. Therefore, the catalytic activity of Pt/Ta 2 O 5 -La/MWCNTs 30% is lower than that of Pt/Ta 2 O 5 -La/MWCNTs 25%. The electrocatalysts were compared with those reported recently. As shown in Table 4 , the electrocatalytic activity of the Pt/Ta 2 O 5 -La/MWCNTs catalyst for methanol oxidation is higher than that of other catalysts. The research results above demonstrate that the addition of La enhances the conductivity of Ta 2 O 5 , amplifies the role of Ta 2 O 5 , and boosts the catalytic activity of the catalyst. The chronoamperometric curve was used to investigate the long-term catalytic stability of catalysts with different La doping levels, as shown in Fig. 10 . The test conditions included a fixed potential of 0.60 V, nitrogen-saturated 0.5 M H 2 SO 4 + 1.0 M CH 3 OH mixed solution, and scanning for 3600 seconds. It can be seen from the figure that the current density of these catalysts significantly decreases at the initial stage of the chronoamperometric test. This reduction is attributed to the formation of intermediate species (such as CO ads , CHO ads , etc. ) that occupy the catalytic sites of the catalyst [ 35 ] , leading to catalyst poisoning. When scanning to the endpoint, the catalytic current density of the three catalysts was maintained at a certain value. The final current densities of 15%, 20%, 25%, and 30% Pt/Ta 2 O 5 -La/MWCNTs catalysts were 88. 50 mA·mg − 1 Pt , 144.96 mA·mg − 1 Pt , 248.9 mA·mg − 1 Pt , and 103.79 mA·mg − 1 Pt , respectively. These values were 29.5%, 32.2%, 44.1%, and 37.8% higher than those of Pt/Ta 2 O 5 /MWCNTs catalysts. The durability of the Pt/Ta 2 O 5 -La/MWCNTs 025% catalyst is superior to other catalysts. Figure 11 illustrates the comparison curve of the electrochemical active surface area and methanol catalytic activity of Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 /MWCNTs, and commercial Pt/C catalysts. From Fig. 11 (a), it can be seen intuitively that the peak shape of the hydrogen adsorption-desorption peak of the Pt/Ta 2 O 5 -La/MWCNTs-25% catalyst is sharper, and the ESA value is higher than that of Pt/Ta 2 O 5 /MWCNTs and commercial Pt/C catalysts. This indicates that the catalytic potential of La-doped Pt/Ta 2 O 5 /MWCNTs catalysts is greater than that of Pt/Ta 2 O 5 /MWCNTs and commercial Pt/C catalysts. The ESA values of Pt/Ta 2 O 5 -La/MWCNTs-25% are 1.5 times higher than those of Pt/Ta 2 O 5 /MWCNTs and 1.9 times higher than commercial Pt/C catalysts, respectively 1.5 times and 1.9 times. Figure 11 (b) illustrates Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 /MWCNTs, and commercial Pt/C catalysts, comparing their MOR activity with that of the Pt/C catalyst. Pt/Ta 2 O 5 -La/MWCNTs-25% exhibits 1.9 times and 3.2 times the MOR activity of Pt/Ta 2 O 5 /MWCNTs and commercial Pt/C catalysts, respectively. The starting potentials of Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 /MWCNTs, and commercial Pt/C catalysts are 0.42 V, 0.43 V, and 0.46 V, respectively. This indicates that the catalytic reaction of La-doped Pt/Ta 2 O 5 /MWCNTs catalyst is more favorable. Figure 11 (c) shows the I-t comparison chart of the three catalysts. It can be seen from the figure that after 3600 seconds, the termination activities of Pt/Ta 2 O 5 -La/MWCNTs-25%, Pt/Ta 2 O 5 /MWCNTs, and commercial Pt/C catalysts are 248.9 mA·mg − 1 Pt , 110.73 mA·mg − 1 Pt , and 49.79 mA·mg − 1 Pt , respectively, with 44. 1%, 34.2%, and 25.8% of the initial activity ratios remaining. Therefore, La doping is more conducive to improving the activity and stability of Pt/Ta 2 O 5 /MWCNTs catalysts. 4. Conclusion In summary, XRD and Raman characterization of the catalyst, it can be confirmed that Pt, Ta 2 O 5 , and La have been successfully loaded onto the multi-wall carbon nanotubes. They have occupied the defect sites on the surface of the multi-wall carbon nanotubes. The calculation of lattice parameters proves that La has been successfully doped into the lattice of Ta 2 O 5 . TEM characterization confirmed that the catalyst nanoparticles had been well dispersed on the multi-wall carbon nanotubes. Clear lattice stripes were obtained, proving that the catalyst particles had good crystallinity. It shows that there is a strong electron coupling effect between Pt, La, and Ta 2 O 5 . The electron transfer from Ta 2 O 5 and La to Pt promotes the formation of Pt 0 , thereby enhancing the utilization of platinum atoms in the catalyst. The analysis of hydrogen adsorption and desorption peaks and CO-stripping indicates that the catalyst Pt/Ta 2 O 5 -La/MWCNTs-25% exhibits the highest electrochemically active surface area. Furthermore, the results from the MOR test demonstrate that the catalyst Pt/Ta 2 O 5 -La/MWCNTs achieves optimal electrocatalytic activity when the lanthanum doping concentration is 25%. The stability of the catalyst is assessed through chronoamperometry, revealing that the Pt/Ta 2 O 5 -La/MWCNTs-25% catalyst maintains 44.1% of its activity after 3600 seconds, thereby confirming that this catalyst configuration possesses superior stability at a lanthanum doping level of 25%. Declarations Author Contribution Bohua Wu: Writing - Review & Editing, Supervision, Funding acquisition Xicheng Lu: Writing - Original Draft, Investigation, Formal analysisFengxiao Du: Resources, Investigation, Data CurationYifan Liu: Visualization, ConceptualizationXiaoqin Wang: Project administration, MethodologyShanxin Xiong: Funding acquisition, Validation Acknowledgments This work was financially supported by NSFC (21303134) and Outstanding Youth Science Fund of Xi’an University of Science and Technology (2018YQ2-13). References Alias M S, Kamarudin S K, Zainoodin A M, et al. Active direct methanol fuel cell: An overview[J]. International Journal of Hydrogen Energy, 2020, 45(38): 19620–19641. Boni M, Velisala V, Kattela S, et al. Comparison of the Anode Side Catalyst Supports with and without Incorporation of Liquid Electrolyte Layer on the Performance of a Passive Direct Methanol Fuel Cell[J]. International Journal of Energy Research, 2023, 2023(1): 1224995. Chen R, Wang Z, Chen S, et al. Optimizing Intermediate Adsorption on Pt Sites via Triple-Phase Interface Electronic Exchange for Methanol Oxidation[J]. Inorganic Chemistry, 2024, 63(9): 4364–4372. Shen B, Yao H, He H, et al. Anchoring Ultrasmall Pt Nanocrystals onto Carbon Nanohorn-Decorated 3D Graphene Networks to Boost Methanol Oxidation Reaction[J]. International Journal of Energy Research, 2023, 2023(1): 7030594. Martinez Mora O, Leon-Fernandez L F, Fransaer J, et al. Enhancing Direct Methanol Oxidation with Pt-Pd Alloy Nanoparticles Synthesized By Gas Diffusion Electrocrystallization (GDE x )[C]//Electrochemical Society Meeting Abstracts 244. The Electrochemical Society, Inc., 2023 (41): 2045–2045. Liu C, Zhang L, Sun L, et al. Enhanced electrocatalytic activity of PtCu bimetallic nanoparticles on CeO 2 /carbon nanotubes for methanol electro-oxidation [J]. International Journal of Hydrogen Energy, 2020, 45(15): 8558–8567. Song H, Qiu X, Li F. 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Complementary ab initio and X-ray nanodiffraction studies of Ta 2 O 5 [J]. Acta materialia, 2015, 83: 276–284. Pan L, Beck D R. La – binding energies by analysis of its photodetachment spectra[J]. Physical Review A, 2016, 93(6): 062501. Gao W, Zhang Z, Dou M, et al. Highly dispersed and crystalline Ta 2 O 5 anchored Pt electrocatalyst with improved activity and durability toward oxygen reduction: promotion by atomic-scale Pt–Ta 2 O 5 interactions[J]. ACS Catalysis, 2019, 9(4): 3278–3288. Rivera M A, Sebastian P J, Gamboa S A, et al. Electrochemical hydrogen absorption in Ni foam[J]. International journal of hydrogen energy, 2000, 25(3): 197–202. Selvan R K, Lee Y S. Pt decorated Artocarpus heterophyllus seed derived carbon as an anode catalyst for DMFC application[J]. RSC advances, 2016, 6(67): 62680–62694. Wu B, Du F, Wang H, et al. Effects of annealing temperature of PtCu/MWCNTS catalysts on their electrocatalytic performance of electrooxidation of methanol [J]. Ionics, 2022, 28(1):369–382. Wu B, Zhu J, Yin S, et al. 4-aminobenzensulphonate‐assisted enhanced hydrophily of carbon nanotubes and simultaneous uniform dispersion of PtRu nanoparticles [J]. Micro &NanoLetters, 2018, 13(5): 728–731. Yan X, Tay B, Yang Y, et al. Fabrication of Three-Dimensional ZnO-Carbon Nanotube (CNT) Hybrids Using Self-Assembled CNT Micropatterns as Framework [J]. J. Phys. Chem. C, 2007, 111(46): 17254–17259. Vecchio C L, Serov A, Dicome M, et al. Investigating the durability of a direct methanol fuel cell equipped with commercial Platinum Group Metal-free cathodic electro-catalysts[J]. Electrochimica Acta, 2021, 394: 139108. Additional Declarations No competing interests reported. Supplementary Files supportimformation.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 20 Nov, 2024 Reviews received at journal 19 Nov, 2024 Reviews received at journal 19 Nov, 2024 Reviewers agreed at journal 19 Nov, 2024 Reviewers agreed at journal 19 Nov, 2024 Reviewers invited by journal 19 Nov, 2024 Submission checks completed at journal 18 Nov, 2024 First submitted to journal 17 Nov, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-5052774\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":false,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":380270013,\"identity\":\"e29af55b-598f-43fd-b613-fbe3633e3e4e\",\"order_by\":0,\"name\":\"Bohua 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(b) C mapping, (c) Pt mapping, (d) O mapping, (e) Ta mapping, (f) La maping.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure6.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/cf047a60db70e6b8949db3c5.jpg\"},{\"id\":69468795,\"identity\":\"1795ddf3-f9bc-4ec5-80d4-e889dad4e846\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:30:46\",\"extension\":\"jpg\",\"order_by\":7,\"title\":\"Figure 7\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":20635,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEDS spectra of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure7.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/7478bb0c2484235918371641.jpg\"},{\"id\":69468787,\"identity\":\"a8cd13e7-9476-483b-8be4-f529f2b88ba5\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:30:44\",\"extension\":\"jpg\",\"order_by\":8,\"title\":\"Figure 8\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":104361,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCV curves of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with 15%, 20%, 25%, and 30% La content in 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e solution under potential of -0.25~1 V with the sweep rate of 50 mv s\\u003csup\\u003e-1\\u003c/sup\\u003e\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure8.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/302f6c3612076486a1395793.jpg\"},{\"id\":69469543,\"identity\":\"532b17e4-8375-4057-962f-836ac65e6318\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:38:45\",\"extension\":\"jpg\",\"order_by\":9,\"title\":\"Figure 9\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1703800,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCV curves of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with 15%, 20%, 25%, and 30% La content and Pt/MWCNTs in 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e + 1 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH solution under potential of 0~1 V with the sweep rate of 50 mv s\\u003csup\\u003e-1\\u003c/sup\\u003e\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure9.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/88227f070ca576b6ad77d88b.jpg\"},{\"id\":69468794,\"identity\":\"e6b4c985-0cb0-46fb-9072-ce5c79e9e84a\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:30:45\",\"extension\":\"jpg\",\"order_by\":10,\"title\":\"Figure 10\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":35909,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eChronoamperometry curves of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with 15%, 20%, 25%, and 30% La content in 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e + 1 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH solution with a measured potential of 0.6 V.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure10.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/3ab6981e1e8a327927392f52.jpg\"},{\"id\":69468808,\"identity\":\"2cf8bd70-36dd-4008-b5fd-662a9f2b591d\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:30:48\",\"extension\":\"jpg\",\"order_by\":11,\"title\":\"Figure 11\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":317232,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCV curves (a) under potential of -0.25~1V with the sweep speed of 50mv s\\u003csup\\u003e-1\\u003c/sup\\u003e, MOR activity (b) under potential of 0~1V with the sweep speed of 50mv s\\u003csup\\u003e-1\\u003c/sup\\u003e, and Chronoamperometry curves(c) of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% , Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, and commercial Pt/C catalysts under potential of 0.6V.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"figure11.tif.jpg\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/38db764c47220bad672ab50e.jpg\"},{\"id\":69470549,\"identity\":\"e35f09a2-6178-485b-9517-d3871c45cb0a\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:54:46\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":3665205,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/8b23970f-6bc0-41f4-99be-7f3146341270.pdf\"},{\"id\":69469545,\"identity\":\"eb33fc1c-a807-4552-8500-8dcdcf5e6778\",\"added_by\":\"auto\",\"created_at\":\"2024-11-20 16:38:46\",\"extension\":\"docx\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":2686686,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"supportimformation.docx\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-5052774/v1/a83d7c23de9a6951c307f2c7.docx\"}],\"financialInterests\":\"No competing interests reported.\",\"formattedTitle\":\"Enhancement of the catalytic activity of Pt nanoparticles toward methanol electro- oxidation using La-doped-Ta 2 O 5 /MWCNTs supporting materials\",\"fulltext\":[{\"header\":\"1. Introduction\",\"content\":\"\\u003cp\\u003eCurrently, platinum-based catalysts remain the optimal choice for direct methanol fuel cell (DMFC) anode catalysts\\u003csup\\u003e[\\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e1\\u003c/span\\u003e]\\u003c/sup\\u003e. However, these catalysts are susceptible to poisoning and aging caused by intermediate carbon compounds such as CO\\u003csub\\u003eads\\u003c/sub\\u003e during methanol oxidation\\u003csup\\u003e[\\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2\\u003c/span\\u003e]\\u003c/sup\\u003e. The adsorption of CO\\u003csub\\u003eads\\u003c/sub\\u003e onto the active site of the catalyst can easily occur, leading to the occupation of the catalytic unit and a significant reduction in catalytic activity. Additionally, the high cost associated with Pt-based catalysts is primarily attributed to their extensive use of platinum.\\u003c/p\\u003e \\u003cp\\u003eSo far, many researchers have studied enhanced Pt catalysts to improve the electrocatalytic activity and durability of electrodes in the alcohol oxidation process\\u003csup\\u003e[\\u003cspan additionalcitationids=\\\"CR4 CR5\\\" citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e3\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e6\\u003c/span\\u003e]\\u003c/sup\\u003e. The results showed that the Pt catalyst modified with a metal oxide support significantly improved the methanol oxidation. For example, Song et al. \\u003csup\\u003e[\\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e7\\u003c/span\\u003e]\\u003c/sup\\u003e introduced ZrO\\u003csub\\u003e2\\u003c/sub\\u003e into Pt-based catalysts using the sol-gel method to create Pt/ZrO\\u003csub\\u003e2\\u003c/sub\\u003e/CNT catalysts. The promotional effect can be attributed to the bifunctional mechanism between Pt and zirconium dioxide. Zhang et al. \\u003csup\\u003e[\\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e8\\u003c/span\\u003e]\\u003c/sup\\u003e prepared a PANI-modified MoO\\u003csub\\u003e3\\u003c/sub\\u003e nanorod-supported Pt catalyst. The results showed that the Pt/PANI-MoO\\u003csub\\u003e3\\u003c/sub\\u003e catalyst, supported by PANI-modified molybdenum trioxide nanorods, exhibited higher catalytic activity than the Pt/PANI catalyst supported by PANI nanotubes. Tantalum pentoxide in metal oxides is famous for its excellent mechanical, thermal, optical, and electrical properties\\u003csup\\u003e[\\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e9\\u003c/span\\u003e]\\u003c/sup\\u003e. It has been widely used in the manufacture of structural ceramic devices, gas sensors, catalysts, and optoelectronic devices\\u003csup\\u003e[\\u003cspan additionalcitationids=\\\"CR11 CR12\\\" citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e10\\u003c/span\\u003e\\u0026ndash;\\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e13\\u003c/span\\u003e]\\u003c/sup\\u003e. Its acid and alkali resistance and chemical stability are also excellent\\u003csup\\u003e[\\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e14\\u003c/span\\u003e], [\\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e15\\u003c/span\\u003e]\\u003c/sup\\u003e. Therefore, it is essential to introduce Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e into the development and research of fuel cells. This introduction can enhance the catalyst's activity and improve its acid and alkali corrosion resistance and electrochemical performance. However, the application of pure tantalum pentoxide is hindered by its weak electronic conductivity\\u003csup\\u003e[\\u003cspan citationid=\\\"CR16\\\" class=\\\"CitationRef\\\"\\u003e16\\u003c/span\\u003e],[\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e17\\u003c/span\\u003e]\\u003c/sup\\u003e and tendency to agglomerate\\u003csup\\u003e[\\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e18\\u003c/span\\u003e]\\u003c/sup\\u003e.\\u003c/p\\u003e \\u003cp\\u003eIn order to make tantalum pentoxide a better carrier for platinum based catalysts, many scientists have attempted to increase current density and increase active sites. The Ishihara team\\u003csup\\u003e[\\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e19\\u003c/span\\u003e]\\u003c/sup\\u003e has prepared C and N doped Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e electrocatalyst and demonstrated the good ORR capability of the catalyst. Wu et al. \\u003csup\\u003e[\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e20\\u003c/span\\u003e]\\u003c/sup\\u003e doped Ru into Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e to support Pt catalyst to prepare Pt/Ru-Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e catalyst, and its catalyst has good dispersion, improving the catalytic activity and stability. It is proved that element doping is a very effective method to improve the conductivity of tantalum pentoxide.\\u003c/p\\u003e \\u003cp\\u003eIn this work, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e doped with the rare metal lanthanum is deposited onto multi-walled carbon nanotubes to enhance the conductivity and electrochemical performance of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. The preparation process is shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. Lanthanum doping may enhance the electronic conductivity of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e and increase the electrochemically active surface area, thereby improving the electrocatalytic activity associated with the charge transfer process. Lanthanum doping can also boost the dissociation of water and regulate the poisoning effect of intermediate CO. Lanthanum was loaded onto Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs using the hydrothermal method, and then Pt was loaded onto Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs using the sodium borohydride-ethylene glycol double reduction method. Finally, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with high catalytic activity and stability were synthesized, and the influence of different doping amounts of La on the catalytic activity of the catalyst was discussed. The physical structure is characterized by X-ray photoelectron spectroscopy, transmission electron microscopy, Raman spectroscopy, field emission scanning electron microscopy, and X-ray diffraction. The electrochemically active surface area, electrocatalytic activity, rate-determining steps, and stability of the catalyst are determined by cyclic voltammetry and timing currents.\\u003c/p\\u003e\"},{\"header\":\"2. Experimental\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.1.Materials\\u003c/h2\\u003e \\u003cp\\u003eMWCNTs was were purchased from Nanjing Xianfeng Nanomaterial Science and Technology Co., Ltd. with a pore size of 20\\u0026ndash;60 nm. 98% analytical pure concentrated sulfuric acid and concentrated nitric acid purchased from Beijing Chemical plant. 5 wt% Nafion was purchased from Alfa Esha (Tianjin) Chemical Co., Ltd. Other chemicals were of analytical grade and used as received.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.2. Preparation of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts\\u003c/h2\\u003e \\u003cp\\u003eThe acid functionalization of MWCNTs was conducted using a mixed acid solution comprising H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e and HNO\\u003csub\\u003e3\\u003c/sub\\u003e. Specifically, 5g carbon nanotubes were combined with 120 mL of a concentrated mixed acid solution, which consisted of 98 wt% H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e and 40 mL of concentrated nitric acid. This mixture was subsequently transferred to a 250 mL three-port flask, where it was subjected to condensation and reflux at a temperature of 60\\u0026deg;C for a duration of 5 hours. Following the reaction, the mixture was allowed to cool naturally to room temperature, diluted tenfold with water, and allowed to precipitate for 12 hours. The supernatant was then decanted, and the precipitate was filtered using a membrane filter. The resulting precipitate was washed with distilled water until a pH of 7 was achieved, yielding the acid-functionalized MWCNTs.After drying at 60\\u0026deg;C for 12 hours in a vacuum drying oven, the acid-functionalized MWCNTs were obtained and designated as MWCNTs-AO.\\u003c/p\\u003e \\u003cp\\u003eA total of 100 mg of MWCNTs-AO was dispersed in 50 mL of anhydrous ethanol through ultrasonic agitation for 30 minutes. Following this, 169 \\u0026micro;L of a TaCl\\u003csub\\u003e5\\u003c/sub\\u003e solution in n-butanol, with a concentration of 200 mg/mL, was added to the dispersion. The mixture underwent an additional 30 minutes of ultrasonic treatment and stirring until the complete evaporation of ethanol was achieved, resulting in the formation of Ta(OH)\\u003csub\\u003em\\u003c/sub\\u003e(OC\\u003csub\\u003e2\\u003c/sub\\u003eH\\u003csub\\u003e5\\u003c/sub\\u003e)\\u003csub\\u003en\\u003c/sub\\u003e/MWCNTs. The resultant mixture was subsequently ground and transferred to a vacuum drying oven, where it was dried at 60\\u0026deg;C for 8 hours. Finally, the material was subjected to calcination at 800\\u0026deg;C for 180 minutes in a nitrogen atmosphere, with a heating rate of 10\\u0026deg;C per minute, culminating in the preparation of the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs.\\u003c/p\\u003e \\u003cp\\u003ePt nanoparticles were immobilized onto a Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs support utilizing a dual reduction methodology. A chloroplatinic acid solution was initially prepared, achieving a concentration of 7.532 mg Pt/mL. Subsequently, 80 mg of the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs support was measured and introduced into 50 mL of ethylene glycol, followed by ultrasonic dispersion for a duration of 30 minutes. After this, 2.65 mL of H\\u003csub\\u003e2\\u003c/sub\\u003ePtCl\\u003csub\\u003e6\\u003c/sub\\u003e solution was incorporated and the mixture was stirred. During the stirring phase, the pH was adjusted to approximately 11 using a 1M NaOH solution. A rapid addition of 10 mL of a 24 mg/mL NaBH\\u003csub\\u003e4\\u003c/sub\\u003e solution was made to the mixture, which was then subjected to ultrasonic treatment for an additional 30 minutes. The reaction proceeded under reflux conditions at 120\\u0026deg;C for 3 hours. Upon completion of the reaction, the solution was allowed to cool to room temperature and was subsequently centrifuged. The resultant precipitate was washed three times with both deionized water and anhydrous ethanol, followed by vacuum drying at 60\\u0026deg;C for 12 hours to yield the desired Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalyst. The platinum loading was determined to be 20 wt%, while the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e loading was 17 wt%.\\u003c/p\\u003e \\u003cp\\u003eLa particles were deposited onto the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs support via a hydrothermal method. A total of 100 mg of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs was utilized as the carrier, to which a specified volume of 20 mL of La(NO\\u003csub\\u003e3\\u003c/sub\\u003e)\\u003csub\\u003e3\\u003c/sub\\u003e solution was added and mixed using ultrasonic agitation for 30 minutes. The mixture was then transferred to a 45 mL PTFE-lined reactor and subjected to a temperature of 200\\u0026deg;C for 240 minutes. Following centrifugation, the product was washed with water and ethanol multiple times, and subsequently dried in a vacuum oven at 60\\u0026deg;C for 12 hours to produce La-doped Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, designated as Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs. The mass fractions of lanthanum incorporated were 15%, 20%, 25%, and 30%.\\u003c/p\\u003e \\u003cp\\u003eFurthermore, Pt nanoparticles were loaded onto the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs support using a double reduction technique. The chloroplatinic acid solution was prepared in advance, maintaining a concentration of 7.532 mg Pt/mL. An amount of 80 mg of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs was weighed and combined with 50 mL of ethylene glycol, followed by ultrasonic dispersion for 30 minutes. Subsequently, 2.65 mL of H\\u003csub\\u003e2\\u003c/sub\\u003ePtCl\\u003csub\\u003e6\\u003c/sub\\u003e solution was added, and the mixture was stirred while adjusting the pH to approximately 11 with 1M NaOH. A rapid addition of 10 mL of a 24 mg/mL NaBH\\u003csub\\u003e4\\u003c/sub\\u003e solution was made, and ultrasonic treatment continued for an additional 30 minutes. The condensation reflux reaction was then conducted at 120\\u0026deg;C for 3 hours. After the reaction concluded, the solution was cooled to room temperature, centrifuged, and the final precipitate was washed three times with deionized water and anhydrous ethanol. The target catalyst, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs, was obtained through vacuum drying at 60\\u0026deg;C for 12 hours, with platinum loading at 20 wt% and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e loading at 17 wt%.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.3. Preparation of working electrodes\\u003c/h2\\u003e \\u003cp\\u003eThe electrocatalytic performance of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-15%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-20%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-30%, catalysts was measured in a typical three electrode system performed on a CHI660D electrochemical workstation (Chenhua Instrument Company of Shanghai, China). Glassy carbon electrodes (GC, 5 mm in diameter) coated with the catalyst served as the working electrodes, with a platinum counter electrode and a saturated calomel electrode (SCE). The GC electrode was first polished in a slurry of 0.03 \\u0026micro;m alumina on a polishing cloth and then cleaned by ultrasonication in an ethanol/water mixture (1:1, v/v). At the same time, 3 mg catalyst was dispersed in 3 mL deionized water by ultrasonic wave to prepare a catalyst ink. The surface of the GC electrode was covered with 30 \\u0026micro;L of the catalyst ink and wait until the solvent has evaporated completely. Then 10 \\u0026micro;L of 0.05 wt% Nafion ethanol solution was added drop by drop and wait until the solvent has evaporated completely. Electrochemical measurements, including the cyclic voltammetry (CV) and chronoamperometry (CA) were done with were performed on a CHI660E electrochemical workstation, utilizing a conventional three-electrode cell at room temperature. 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e and 1.0 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH were employed as electrolytes. The CO adsorption and oxidation experiments were carried out using cyclic voltammetry at 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e, and then the CO stripping peak was obtained at a scanning rate of 50 mV s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e. The CO oxidation peak is then integrated to calculate the electrochemically active surface area (ECSA) of the sample.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec6\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.4. Material characterization\\u003c/h2\\u003e \\u003cp\\u003eThe bonding structure of the catalyst was studied using XRD analysis, model Diffractomete-6000, produced by Shimadzu Corporation in Japan. The defects of the material were studied using Raman spectroscopy, using equipment from Renishaw, UK, model inVia Reflex. The microstructure, particle size, and dispersion of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst were characterized using a TEM. The transmission electron microscope model JEM-3010 produced by Japan Electronics Corporation was used. XPS test was employed to analyze the surface composition and oxidation state of the catalysts. XPS analysis was carried out by using the Brooke Company model AXIS Supra. Using a field emission scanning electron microscope produced by Japan Electronics Corporation, model JSM-7610F, the elemental composition and content on the surface of the material was analyzed. CO-stripping were used to determine ESA and MA of catalysts.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"3. Results and Discussion\",\"content\":\"\\n\\u003ch3\\u003e3. 1 Characterization of the morphology and structure of catalyst\\u003c/h3\\u003e\\n\\u003cp\\u003eThe crystal structures of MWCNTs, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs, and Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts were characterized by XRD, as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e(a). According to the Debye-Scherrer formula (1), the particle size of the crystal can be calculated accordingly\\u003csup\\u003e[\\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e21\\u003c/span\\u003e]\\u003c/sup\\u003e:\\u003cdiv class=\\\"BlockQuote\\\"\\u003e\\u003cp\\u003ed\\u0026thinsp;=\\u0026thinsp;0. 9λ/(βcosθ\\u003csub\\u003e111\\u003c/sub\\u003e) (1)\\u003c/p\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003eThe scanning range was 10\\u0026deg; to 80\\u0026deg;, and the scanning speed is 2\\u0026deg;/min. 2θ\\u0026thinsp;=\\u0026thinsp;26.2\\u0026deg; corresponds to the (0 0 2) crystal plane of C. 2θ\\u0026thinsp;=\\u0026thinsp;22.9\\u0026deg;, 28.29\\u0026deg;, and 36.66\\u0026deg; correspond to (0 0 1), (1 10 0), and (1 11 1) crystal planes (JCPDS No. 25\\u0026ndash;0922) of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. 2θ\\u0026thinsp;=\\u0026thinsp;46.1\\u0026deg;, 52.1\\u0026deg;, and 56.0\\u0026deg; correspond to the crystal planes (1 1 0), (1 0 3), and (2 0 1) of La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e (JCPDS No.05-0602). 2θ\\u0026thinsp;=\\u0026thinsp;39.76\\u0026deg; corresponds to the (1 1 1) crystal plane of Pt (JCPDS No.04-0802). It can be confirmed that Pt, La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e have been successfully loaded onto multi-walled carbon nanotubes. According to the Debye-Scherrer formula, it can be calculated that the particle sizes of Pt, La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e are 2.8 nm, 3.8 nm, and 4.9 nm, respectively\\u003csup\\u003e[\\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e22\\u003c/span\\u003e]\\u003c/sup\\u003e. By adding Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, the lattice constants of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e (1 1 1) were calculated by fitting the Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e (1 1 1) planes of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs. The calculation results are shown in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. After La doping, the lattice parameters of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e have changed from 0.2406 nm to 0.2483 nm. The lattice parameters have increased in the direction of La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e, indicating successful doping of La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e into Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. Moreover, the half-peak width of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e increases, and the particle size decreases, demonstrating that doping effectively hinders the gradual agglomeration of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e caused by Ostwald ripening.\\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e(b) shows the XRD patterns of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with varying La doping levels. 2θ\\u0026thinsp;=\\u0026thinsp;39.76\\u0026deg; corresponds to the (1 1 1) crystal plane of each Pt catalyst. It can be seen from the figure that when the La doping amount of the catalyst reaches 25%, the peak intensity at Pt (1 1 1) becomes higher and sharper, indicating an improvement in the crystal form of platinum. Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e presents the particle size analysis of Pt supported on different La contents in Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst. According to the analysis, it was found that Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% has the smallest particle size. Better catalyst crystal form and smaller particle size are conducive to improving the activity of methanol electrocatalytic oxidation.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eLattice parameter of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"3\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eTa\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eTa\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eLattice constant (nm)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.2406\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.2483\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e2θ\\u003csub\\u003e(1 11 1)\\u003c/sub\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e37.10\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e36.25\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eFWHM(degree)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1.170\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.898\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eParticle size (nm)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5.48\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e4.91\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eThe size of Pt with different La content\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eDoping\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2θ (\\u0026deg;)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eFWHM (\\u0026deg;)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eD (nm)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e15%\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e39.76\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.5151\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e3.6\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e20%\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e39.76\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.6724\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e3.2\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e25%\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e39.76\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.8099\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e2.8\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e30%\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e39.76\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e2.5652\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e3.3\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eRaman spectroscopy was used to study the surface structure and defect degree of catalysts. Raman spectroscopy was used to characterize\\u003c/p\\u003e \\u003cp\\u003eMWCNTs catalysts, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalysts, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts, and Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts, as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e. The peak at 1377 cm\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e is the D\\u0026acute; peak, which is due to the double resonance effect in the disordered carbon system. The peak at 1573 cm\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e is called the G peak, corresponding to the E\\u003csub\\u003e2g\\u003c/sub\\u003e modulus of the ordered structure of graphite. The peak near 1605 cm\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e is called the D' peak, and its presence corresponds to defects in the hexagonal graphite structure. Therefore, the relative strength ratio of I\\u003csub\\u003eD\\u003c/sub\\u003e/I\\u003csub\\u003eG\\u003c/sub\\u003e can be used to explore the structural purity of graphite materials \\u003csup\\u003e[\\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e23\\u003c/span\\u003e]\\u003c/sup\\u003e. The I\\u003csub\\u003eD\\u003c/sub\\u003e/I\\u003csub\\u003eG\\u003c/sub\\u003e values of MWCNTs, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs, and Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs are 1.37, 1.19, 1.22, and 1.01, respectively. Among them, the I\\u003csub\\u003eD\\u003c/sub\\u003e/I\\u003csub\\u003eG\\u003c/sub\\u003e value of MWCNTs is the highest, which is caused by a large number of defects on the surface of functionalized multi-wall carbon nanotubes. With the formation of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, La, and Pt nanoparticles, they are dispersed on the functionalized multi-wall carbon nanotubes, covering more defect sites on the surface of MWCNTs. As a result, the I\\u003csub\\u003eD\\u003c/sub\\u003e/I\\u003csub\\u003eG\\u003c/sub\\u003e value decreases, and the relative strength of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst is the lowest.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe microstructure, particle size, and dispersion of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst were characterized using a TEM. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e illustrates the dispersion of catalyst nanoparticles on multi-walled carbon nanotubes. As depicted in the figure, the nanoparticles exhibit good dispersibility with minimal agglomeration and well-defined crystal boundaries, suggesting that the catalyst particles maintain a stable crystal structure without dissolution. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e(c) and Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e(d) are HRTEM images of the catalyst. Clear lattice stripes can be observed in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e(c) and d, indicating the catalyst particles' good crystallinity. The distance between lattice stripes measures approximately 0.19 nm and 0.23 nm, corresponding to the lattice spacing of Pt (2 0 0) and (1 1 1)\\u003csup\\u003e[\\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e24\\u003c/span\\u003e]\\u003c/sup\\u003e planes, respectively. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e displays the histogram of the particle size distribution of 50 nanoparticles randomly selected on the catalyst surface. Through measurement and calculation, the catalyst particle size on the surface of multi-walled carbon nanotubes is mainly between 2 nm and 10 nm, with an average particle size of 4.8 nm. This average particle size aligns with the calculation derived from XRD. Generally, a smaller catalyst particle size will have a larger specific surface area, providing more active site. This can enhance the catalytic activity of the catalyst.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eXPS was used to study the elemental composition and the valence state of each element in the catalyst. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e shows the XPS spectrum of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNT catalyst. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(a) shows that Pt, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, and La have been successfully loaded onto multi-walled carbon nanotubes in each La-doped catalyst. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(b) shows the XPS spectrum of a Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNT catalyst with 25% La doping. After correction, it shows the presence of Pt, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, La, and C. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(c) displays the high-resolution C\\u003csub\\u003e1s\\u003c/sub\\u003e XPS spectrum. The peaks centered at 284.8 eV and 286.3 eV in the figure can be attributed to the sp\\u003csup\\u003e2\\u003c/sup\\u003e hybrid C-C bond and C-O bond, respectively. The peak with a binding energy of 290. 0 eV can be attributed to O-C\\u0026thinsp;=\\u0026thinsp;O.As shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(d), the high-resolution Ta 4f XPS spectrum displays a pair of peaks at the binding energies of 28.4 eV and 26.4 eV, corresponding to the binding energy of Ta\\u003csup\\u003e5+\\u003c/sup\\u003e, which confirms the formation of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. As shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(e), the high-resolution La 3d XPS spectrum displays a pair of peaks at binding energies of 852.6 eV and 834.8 eV, respectively, corresponding to the La\\u003csup\\u003e3+\\u003c/sup\\u003e binding energy, confirming the presence of La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e\\u003csup\\u003e[\\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e25\\u003c/span\\u003e]\\u003c/sup\\u003e. As shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e(f), the two peaks in the high-resolution Pt 4f XPS spectrum at the binding energies of 74.0 eV and 70.6 eV can correspond to the formation of Pt\\u003csup\\u003e0\\u003c/sup\\u003e, while the peaks at the binding energies of 75.4 eV, 72.0 eV and 77.9 eV, 74.5 eV correspond to PtO and the peaks at 77.9 eV and 74.5 eV correspond to PtO\\u003csub\\u003e2\\u003c/sub\\u003e, respectively. Compared with the standard binding energy of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e\\u003csup\\u003e[\\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e26\\u003c/span\\u003e][\\u003cspan citationid=\\\"CR27\\\" class=\\\"CitationRef\\\"\\u003e27\\u003c/span\\u003e]\\u003c/sup\\u003e, the binding energy of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst Ta 4f shifted 0.3 eV in the positive direction. The binding energy of the electron at La 3d\\u003csup\\u003e[\\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e28\\u003c/span\\u003e]\\u003c/sup\\u003e shifted forward by 0.2 eV compared with the standard La\\u003csup\\u003e3+\\u003c/sup\\u003e binding energy. The electron binding energy at Pt 4f experienced a negative shift of 0.4 eV compared with the standard Pt\\u003csup\\u003e0\\u003c/sup\\u003e binding energy. It shows that there is a strong electron coupling effect between Pt, La, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. The electron transfer from Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e\\u003csup\\u003e[\\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e29\\u003c/span\\u003e]\\u003c/sup\\u003e and La\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e to Pt promotes the formation of Pt\\u003csup\\u003e0\\u003c/sup\\u003e, thereby enhancing the utilization of platinum atoms in the catalyst.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab3\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 3\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eContent of catalyst Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"3\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e\\u0026nbsp;\\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eMoore's share\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eQuality as a percentage\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eC\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e62.75\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e40.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eO\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e9.75\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e8.28\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eLa\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e11.38\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e16.84\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTa\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e14.05\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e13.44\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePt\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e2.06\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e21.42\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eTable\\u0026nbsp;\\u003cspan refid=\\\"Tab3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e shows the content of each element obtained by fitting the XPS peak value of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst. The molar ratios of C, O, La, Ta and Pt are 62.75%, 9.75%, 11.38%, 14.05% and 2.06% respectively, and the mass ratios are 40.02%, 8.28%,16.84%, 13.44% and 21.42% respectively.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e displays the field emission scanning electron microscope and mapping scanning diagram of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst. Although the presence of catalyst nanoparticles is not obvious in the FESEM image, the smaller agglomeration can be used as an indicator of a well-distributed nanoparticles. Since the distribution of catalyst particles in FESEM images is not clear, we also conducted mapping analysis on Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs. The images related to different elements are shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e. The elemental mapping confirmed the uniform distribution of Pt, La, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e nanoparticles on the surface of MWCNTs through spectrum analysis. The element map in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e(a) shows that the doping effect is ideal. As shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig7\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003e, the elemental composition of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs surface was studied through EDS analysis. It can be seen from the figure that the presence of peaks corresponding to Pt, La, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e confirms the successful synthesis of Pt, La, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e at the conclusion of the reaction. The mass ratio of catalysts C, Pt, O, La, and Ta is 48.4% : 15.0% : 8.7% : 11.7% : 16.2%, respectively.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e\\n\\u003ch3\\u003e3. 2 Characterization of electrocatalytic properties of catalysts\\u003c/h3\\u003e\\n\\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig8\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003e displays the CV curve of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst with 15%, 20%, 25%, and 30% La doping in a 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e solution. The scanning rate is 50 mV s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e, and the scanning window ranges from \\u0026minus;\\u0026thinsp;0.25 V to 1 V. Typically, the hydrogen adsorption-desorption peak can be utilized to calculate the ESA value of the catalyst\\u003csup\\u003e[\\u003cspan citationid=\\\"CR30\\\" class=\\\"CitationRef\\\"\\u003e30\\u003c/span\\u003e]\\u003c/sup\\u003e. Through calculation, the ESA values of 15%, 20%, 25%, and 30% Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts are 34.2 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 51.3 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 65.0 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e and 48.5 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, respectively. Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25% catalyst has the highest ESA value, indicating that when the La doping amount is 25%, it exhibits the highest catalytic potential and reaction activity. Therefore, it can be inferred that the catalytic activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25% will be higher than that of other catalysts. Although the hydrogen adsorption-desorption peak of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 30% catalyst is similar to that of the La-25% catalyst, the EAS value is low. This is attributed to the large nanoparticle size of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-30% catalyst, as indicated by the XRD calculation results, resulting in a small electrochemical active surface area.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eIn order to ensure the accuracy of the experimental results, we also conducted CO-stripping experiments to calculate ESA. The tolerance of a catalyst to CO is an essential parameter for evaluating its efficacy. This tolerance is generally quantified using a method known as dissolved CO-stripping. This procedure entails the continuous introduction of carbon monoxide gas into a 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e solution while maintaining a constant voltage to promote the adsorption of CO. It can be observed from the voltammograms that for the four catalysts in the first scan, the hydrogen desorption peaks are suppressed in the lower potential region due to the saturation of Pt surface with CO\\u003csub\\u003ead\\u003c/sub\\u003e species. The CO absorption peaks of the four catalysts all appeared near 0.5V. No CO oxidation was monitored in the second scan for the four catalysts, which conforms the complete removal of CO\\u003csub\\u003ead\\u003c/sub\\u003e species.\\u003c/p\\u003e \\u003cp\\u003eAdditionally, the ESA of the catalysts were calculated by integrating the peaks associated with CO oxidation, as outlined in Figure S4. Through calculation, the ESA values of 15%, 20%, 25%, and 30% Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts are 28.3 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 43.7 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 61.5 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e and 47.3 m\\u003csup\\u003e2\\u003c/sup\\u003eg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, the area current is 7.78A m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e, 9.78 A m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e, 9.99 A m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e, 8.04 A m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e, which are similar to the previous calculated values. The results show that 25% lanthanum doped catalyst has the best catalytic activity, followed by 20% and 30%, and finally 15%. The lower activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNT-30% catalyst is due to the poor crystal structure of platinum, which prevents the enhancement of catalytic surface area and catalytic activity of the catalyst.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eIn order to further explore the electrocatalytic methanol oxidation activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs with 15%, 20%, 25%, and 30% La doping, CV tests were conducted in a mixed solution of 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e and 1.0 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH mixed solution with a sweep rate of 50 mV s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e and a potential window of 0 V to 1 V. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig9\\\" class=\\\"InternalRef\\\"\\u003e9\\u003c/span\\u003e illustrates that the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with varying La doping levels and Pt/MWCNTs can be utilized in the reaction of 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e\\u0026thinsp;+\\u0026thinsp;1.0 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH CV curve in a mixed solution. As previously documented, these are all typical cyclic voltammetric curves of MOR. Moreover, the activity of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25% catalyst is up to 614.63 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, which is higher than that of the La-15% (219.95 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e), La-20% (426.92 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e), La-30% (364.42 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e) catalysts and Pt/MWCNTs (297.7 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e). As depicted in the figure, the peak observed during forward scanning corresponds to the methanol oxidation activity, while the peak in reverse scanning represents the oxidation of methanol on the surface, which is associated with the removal of adsorbed CO and HCO species. It can be seen from the figure that the initial potentials of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts with concentrations of 15%, 20%, 25%, and 30% are 0.49V, 0.48V, 0.42V, and 0.42V, respectively. The initial potential of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25% catalyst is lower than that of the other four catalysts including Pt/MWCNTs. This indicates that methanol is more likely to catalyze the reaction on the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTS-25% catalyst. Figure S3 shows the SA of the four prepared catalysts. According to Figure S3, the mass activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/ MWCNT-25% catalyst was the highest, followed by 20%, 30% and 15%. Moreover, the electrocatalytic activities for all the catalysts were also evaluated using mass specific activity (MA) with respect to the peak potential for MOR.According to formula (2)\\u003csup\\u003e[\\u003cspan citationid=\\\"CR31\\\" class=\\\"CitationRef\\\"\\u003e31\\u003c/span\\u003e]\\u003c/sup\\u003e:\\u003cdiv id=\\\"Equ1\\\" class=\\\"Equation\\\"\\u003e\\u003cdiv format=\\\"TEX\\\" class=\\\"mathdisplay\\\" id=\\\"FileID_Equ1\\\" name=\\\"EquationSource\\\"\\u003e\\n$$\\\\:{M}_{A}\\\\:=\\\\:\\\\frac{{Q}_{H}}{{L}_{Pt}}$$\\u003c/div\\u003e\\u003cdiv class=\\\"EquationNumber\\\"\\u003e2\\u003c/div\\u003e\\u003c/div\\u003e\\u003c/p\\u003e \\u003cp\\u003eQ\\u003csub\\u003eH\\u003c/sub\\u003e is the charge density for the methanol oxidation peak (mC cm\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e) and L is the loading of Pt in the electrode (mg cm\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab4\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 4\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eMethanol oxidation behavior of various electrocatalysts\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"4\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"char\\\" char=\\\".\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eCatalyst\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003ePeak current potential\\u003c/p\\u003e \\u003cp\\u003e(V vs. SCE)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003ePeak current\\u003c/p\\u003e \\u003cp\\u003e(mA mg \\u003csub\\u003ePt\\u003c/sub\\u003e-1 )\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eReferences\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.66\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e614.63\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eThis work\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePtCu/MWCNTs\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.65\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e504.19\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eReference \\u003csup\\u003e[\\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e32\\u003c/span\\u003e]\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePt\\u003csub\\u003e1\\u003c/sub\\u003eGd\\u003csub\\u003e1\\u003c/sub\\u003e/Gd\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e3\\u003c/sub\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.65\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e425.67\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eReference \\u003csup\\u003e[\\u003cspan citationid=\\\"CR33\\\" class=\\\"CitationRef\\\"\\u003e33\\u003c/span\\u003e]\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePtNi/CNSs\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e0.75\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"char\\\" char=\\\".\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e393.02\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eReference \\u003csup\\u003e[\\u003cspan citationid=\\\"CR34\\\" class=\\\"CitationRef\\\"\\u003e34\\u003c/span\\u003e]\\u003c/sup\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003eAfter calculation, The MA of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-15%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-20%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNT-30% catalyst was 118.7 mC mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e,192.6 mC mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e,258.3 mC mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e,185.2 mC mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e.The catalytic activity of Pt/MWCNTs catalysts was higher than that of 15% doped catalysts but lower than that of 20%, 25%, 30% doped catalysts. Similar to the ESA calculation results, the catalytic activity of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 30% catalyst is also lower than that of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25% catalyst. As revealed by XRD analysis, the size of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-30% catalyst nanoparticles is larger, and the peak intensity and sharpness at Pt (1 1 1) are low. This indicates that the crystal structure of platinum is poor, which hinders the enhancement of the catalytic surface area and catalytic activity of the catalyst. Therefore, the catalytic activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 30% is lower than that of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 25%. The electrocatalysts were compared with those reported recently. As shown in Table\\u0026nbsp;\\u003cspan refid=\\\"Tab4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e, the electrocatalytic activity of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalyst for methanol oxidation is higher than that of other catalysts. The research results above demonstrate that the addition of La enhances the conductivity of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, amplifies the role of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, and boosts the catalytic activity of the catalyst.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eThe chronoamperometric curve was used to investigate the long-term catalytic stability of catalysts with different La doping levels, as shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig10\\\" class=\\\"InternalRef\\\"\\u003e10\\u003c/span\\u003e. The test conditions included a fixed potential of 0.60 V, nitrogen-saturated 0.5 M H\\u003csub\\u003e2\\u003c/sub\\u003eSO\\u003csub\\u003e4\\u003c/sub\\u003e\\u0026thinsp;+\\u0026thinsp;1.0 M CH\\u003csub\\u003e3\\u003c/sub\\u003eOH mixed solution, and scanning for 3600 seconds. It can be seen from the figure that the current density of these catalysts significantly decreases at the initial stage of the chronoamperometric test. This reduction is attributed to the formation of intermediate species (such as CO\\u003csub\\u003eads\\u003c/sub\\u003e, CHO\\u003csub\\u003eads\\u003c/sub\\u003e, etc. ) that occupy the catalytic sites of the catalyst\\u003csup\\u003e[\\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e35\\u003c/span\\u003e]\\u003c/sup\\u003e, leading to catalyst poisoning. When scanning to the endpoint, the catalytic current density of the three catalysts was maintained at a certain value. The final current densities of 15%, 20%, 25%, and 30% Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts were 88. 50 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 144.96 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 248.9 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, and 103.79 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, respectively. These values were 29.5%, 32.2%, 44.1%, and 37.8% higher than those of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalysts. The durability of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs 025% catalyst is superior to other catalysts.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003eFigure \\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e11\\u003c/span\\u003e illustrates the comparison curve of the electrochemical active surface area and methanol catalytic activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, and commercial Pt/C catalysts. From Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e11\\u003c/span\\u003e(a), it can be seen intuitively that the peak shape of the hydrogen adsorption-desorption peak of the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% catalyst is sharper, and the ESA value is higher than that of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs and commercial Pt/C catalysts. This indicates that the catalytic potential of La-doped Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalysts is greater than that of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs and commercial Pt/C catalysts. The ESA values of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% are 1.5 times higher than those of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs and 1.9 times higher than commercial Pt/C catalysts, respectively 1.5 times and 1.9 times. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e11\\u003c/span\\u003e(b) illustrates Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, and commercial Pt/C catalysts, comparing their MOR activity with that of the Pt/C catalyst. Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% exhibits 1.9 times and 3.2 times the MOR activity of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs and commercial Pt/C catalysts, respectively. The starting potentials of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, and commercial Pt/C catalysts are 0.42 V, 0.43 V, and 0.46 V, respectively. This indicates that the catalytic reaction of La-doped Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalyst is more favorable. Figure\\u0026nbsp;\\u003cspan refid=\\\"Fig11\\\" class=\\\"InternalRef\\\"\\u003e11\\u003c/span\\u003e(c) shows the I-t comparison chart of the three catalysts. It can be seen from the figure that after 3600 seconds, the termination activities of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25%, Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs, and commercial Pt/C catalysts are 248.9 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, 110.73 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, and 49.79 mA\\u0026middot;mg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e\\u003csub\\u003ePt\\u003c/sub\\u003e, respectively, with 44. 1%, 34.2%, and 25.8% of the initial activity ratios remaining. Therefore, La doping is more conducive to improving the activity and stability of Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs catalysts.\\u003c/p\\u003e\"},{\"header\":\"4. Conclusion\",\"content\":\"\\u003cp\\u003eIn summary, XRD and Raman characterization of the catalyst, it can be confirmed that Pt, Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e, and La have been successfully loaded onto the multi-wall carbon nanotubes. They have occupied the defect sites on the surface of the multi-wall carbon nanotubes. The calculation of lattice parameters proves that La has been successfully doped into the lattice of Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. TEM characterization confirmed that the catalyst nanoparticles had been well dispersed on the multi-wall carbon nanotubes. Clear lattice stripes were obtained, proving that the catalyst particles had good crystallinity. It shows that there is a strong electron coupling effect between Pt, La, and Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e. The electron transfer from Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e and La to Pt promotes the formation of Pt\\u003csup\\u003e0\\u003c/sup\\u003e, thereby enhancing the utilization of platinum atoms in the catalyst.\\u003c/p\\u003e \\u003cp\\u003eThe analysis of hydrogen adsorption and desorption peaks and CO-stripping indicates that the catalyst Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% exhibits the highest electrochemically active surface area. Furthermore, the results from the MOR test demonstrate that the catalyst Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs achieves optimal electrocatalytic activity when the lanthanum doping concentration is 25%. The stability of the catalyst is assessed through chronoamperometry, revealing that the Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs-25% catalyst maintains 44.1% of its activity after 3600 seconds, thereby confirming that this catalyst configuration possesses superior stability at a lanthanum doping level of 25%.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003ch2\\u003eAuthor Contribution\\u003c/h2\\u003e\\u003cp\\u003eBohua Wu: Writing - Review \\u0026amp; Editing, Supervision, Funding acquisition Xicheng Lu: Writing - Original Draft, Investigation, Formal analysisFengxiao Du: Resources, Investigation, Data CurationYifan Liu: Visualization, ConceptualizationXiaoqin Wang: Project administration, MethodologyShanxin Xiong: Funding acquisition, Validation\\u003c/p\\u003e\\u003ch2\\u003eAcknowledgments\\u003c/h2\\u003e \\u003cp\\u003eThis work was financially supported by NSFC (21303134) and Outstanding Youth Science Fund of Xi\\u0026rsquo;an University of Science and Technology (2018YQ2-13).\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\u003cli\\u003e\\u003cspan\\u003eAlias M S, Kamarudin S K, Zainoodin A M, et al. Active direct methanol fuel cell: An overview[J]. International Journal of Hydrogen Energy, 2020, 45(38): 19620\\u0026ndash;19641.\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eBoni M, Velisala V, Kattela S, et al. Comparison of the Anode Side Catalyst Supports with and without Incorporation of Liquid Electrolyte Layer on the Performance of a Passive Direct Methanol Fuel Cell[J]. International Journal of Energy Research, 2023, 2023(1): 1224995.\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eChen R, Wang Z, Chen S, et al. Optimizing Intermediate Adsorption on Pt Sites via Triple-Phase Interface Electronic Exchange for Methanol Oxidation[J]. Inorganic Chemistry, 2024, 63(9): 4364\\u0026ndash;4372.\\u003c/span\\u003e\\u003c/li\\u003e \\u003cli\\u003e\\u003cspan\\u003eShen B, Yao H, He H, et al. Anchoring Ultrasmall Pt Nanocrystals onto Carbon Nanohorn-Decorated 3D Graphene Networks to Boost Methanol Oxidation Reaction[J]. 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Electrochimica Acta, 2021, 394: 139108.\\u003c/span\\u003e\\u003c/li\\u003e\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":false,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":true,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"ionics\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"\",\"sideBox\":\" Learn more about [Ionics](https://www.springer.com/journal/11581) \",\"snPcode\":\"11581\",\"submissionUrl\":\"https://mc.manuscriptcentral.com/ionics\",\"title\":\"Ionics\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false},\"keywords\":\"Anodes, Ta2O5, Lanthanum, Pt, Nanoparticles, Composite materials, Electrocatalysis\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-5052774/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-5052774/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eIn this work, La-doped Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e was synthesized as support for Pt nanoparticles by hydrothermal method. The prepared Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts were characterized by TEM, XRD and XPS. These characterization methods confirm that Pt nanoparticles were successfully supported on La-doped Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e/MWCNTs. The TEM reveals that the catalyst particle size on the surface of multi-walled carbon nanotubes is mainly between 2 nm and 10 nm, with an average particle size of 4.8 nm. The further electrochemical characterizations including CV, show that Pt/Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs catalysts have larger electrochemical surface area, better electrocatalytic activity and higher stability towards the methanol oxidation reaction compared to the carbon supported Pt catalysts. The excellent electrocatalytic performance is mainly contributed to the smaller particle size and more uniform dispersion of Pt nanoparticles. This work demonstrated that Ta\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e5\\u003c/sub\\u003e-La/MWCNTs is a promising anode catalyst support for direct methanol fuel cells.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Enhancement of the catalytic activity of Pt nanoparticles toward methanol electro- oxidation using La-doped-Ta 2 O 5 /MWCNTs supporting materials\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-11-20 16:30:39\",\"doi\":\"10.21203/rs.3.rs-5052774/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0},{\"type\":\"decision\",\"content\":\"Revision requested\",\"date\":\"2024-11-20T16:36:15+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2024-11-20T04:08:05+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"editorInvitedReview\",\"content\":\"\",\"date\":\"2024-11-19T18:22:57+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"41980650901762228681004600700940101017\",\"date\":\"2024-11-19T17:14:54+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewerAgreed\",\"content\":\"116601158263573841063093233124265218790\",\"date\":\"2024-11-19T15:51:06+00:00\",\"index\":\"hide\",\"fulltext\":\"\"},{\"type\":\"reviewersInvited\",\"content\":\"\",\"date\":\"2024-11-19T14:16:36+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"checksComplete\",\"content\":\"\",\"date\":\"2024-11-19T03:30:42+00:00\",\"index\":\"\",\"fulltext\":\"\"},{\"type\":\"submitted\",\"content\":\"Ionics\",\"date\":\"2024-11-17T13:48:01+00:00\",\"index\":\"\",\"fulltext\":\"\"}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"ionics\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":false,\"externalIdentity\":\"\",\"sideBox\":\" Learn more about [Ionics](https://www.springer.com/journal/11581) \",\"snPcode\":\"11581\",\"submissionUrl\":\"https://mc.manuscriptcentral.com/ionics\",\"title\":\"Ionics\",\"twitterHandle\":\"\",\"acdcEnabled\":true,\"dfaEnabled\":true,\"editorialSystem\":\"stoa\",\"reportingPortfolio\":\"Springer Hybrid\",\"inReviewEnabled\":true,\"inReviewRevisionsEnabled\":false}}],\"origin\":\"\",\"ownerIdentity\":\"83854e91-c4f7-47ae-9803-9bf898c0e21c\",\"owner\":[],\"postedDate\":\"November 20th, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"under-review\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2025-02-24T12:08:54+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2024-11-20 16:30:39\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-5052774\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-5052774\",\"identity\":\"rs-5052774\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}