Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst

Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst | 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 Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst Daniel Gallego-García, Mark E. Martínez-Klimov, Päivi Mäki-Arvela, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6922102/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Jan, 2026 Read the published version in Environmental Chemistry Letters → Version 1 posted 4 You are reading this latest preprint version Abstract The efficient production of sustainable aviation fuels (SAFs) from lignin-derived biomass remains a major challenge due to the difficulty of simultaneously generating both aromatics and cycloalkanes in the specific ratios required by fuel specifications. In particular, hydrodeoxygenation (HDO) of isoeugenol involves competing pathways: full hydrogenation to produce cycloalkanes, and selective deoxygenation that preserves the aromatic ring. To date, no catalytic system has successfully combined high selectivity for both hydrocarbon classes under mild conditions. Here, we demonstrate that a nickel aluminate spinel-derived catalyst, synthesized via a simple one-pot sol-gel method, overcomes this limitation by enabling, for the first time, the direct production of SAF-compatible blends with 16 wt% aromatics and 30 wt% cycloalkanes at 275°C and 20 bar H 2 . The superior selectivity arises from the tailored structural and surface properties of the spinel support, which balance hydrogenation and deoxygenation pathways. The catalyst exhibits excellent reproducibility, facile product separation, and scalability, offering a practical route for one-pot, large-scale SAF production from lignocellulosic feedstocks. This work addresses a key bottleneck in biomass valorization, representing a significant advance in catalyst design for renewable aviation fuels. Hydrodeoxygenation Biomass valorization: Isoeugenol Nickel aluminate catalyst Aromatic-cycloalkane fuel blend optimization SAF Figures Figure 1 Figure 2 Figure 3 1. Introduction Environmental regulations have boosted global renewable demand across sectors, including aviation. Sustainable aviation fuels (SAFs), derived from renewable biomass, offer a pathway to cut global carbon emissions by up to 80% when fully replacing conventional jet fuel [ 1 ]. SAF requires a complex blend of hydrocarbons, typically comprising n-alkanes (15–25%), iso-alkanes (20–55%), cyclo-alkanes (20–45%) and aromatics (4–25%) (in wt%) [ 2 ]. Despite several ASTM-certified production pathways for SAFs [ 3 , 4 ], most of them lack the sufficient aromatic content. Developing a biomass pathway that directly yields SAFs with suitable aromatics would be a major advance. Isoeugenol, a representative lignin-derived bio-oil model [ 5 ], is central to catalytic HDO for upgrading bio-oils to aviation-grade hydrocarbons [ 6 ]. Preserving isoeugenol’s aromatic structure is key to meeting SAF specifications. In the global reaction network for isoeugenol HDO (Fig. 1 a), propylbenzene (PB) is the key product for the SAFs application. Effective HDO catalysts are bifunctional: metal sites activate H 2 for hydrogenation/dehydrogenation [ 7 – 9 ], while acid sites or oxygen vacancies promote dehydration and C–O cleavage [ 12 – 12 ]. Balancing these sites is crucial to minimize over-hydrogenation and cracking, preserving fuel-range hydrocarbon yield. Early HDO of lignin-derived compounds used sulfided Mo-based catalysts, but their reliance on sulfiding agents limits practical application [ 13 ]. Noble metal catalysts have been studied for isoeugenol HDO (Fig. 1 b) [ 11 , 14 ], but over-hydrogenation lowers fuel-range yields, making transition metals (e.g. Ni, Co) a promising alternative. Isoeugenol HDO selectivity can be tuned via metal choice and support, as support acidity and metal–support interactions influence dispersion, adsorption, and hydrogen activation [ 15 – 17 ]. Despite extensive studies on metals, supports, and feedstocks (Fig. 1 b), SAF-like product distributions with high selectivity for both aromatics and cycloalkanes remain unattainable [ 8 , 18 ]. Here, we report a nickel aluminate spinel-derived catalyst (NiAl) with exceptional HDO performance, producing aromatics and cycloalkanes at SAF-specification yields, readily separable (Fig. 1 c), surpassing previous benchmarks. 2. Experimental Experimental details –including catalyst synthesis, characterization, reaction procedures, product analysis, and metrics − are provided in the Supplementary Information. 3. Results and discussion 3.1. Catalyst characterization Results for a commercial catalyst (HTC-600) with a Ni/Al composition similar to NiAl (Supplementary Table S1 ) are also presented and discussed. The NiAl 2 O 4 spinel structure of the NiAl precursor was confirmed by XRD, UV-Vis DRS and Raman spectroscopy (Supplementary Fig. S1 -S3). The Ni 2p3/2 XPS spectrum (Fig. 2 a) of calcined NiAl exhibited two main bands at ∼855.9 eV and ∼862.2 eV, characteristics of a NiAl 2 O 4 -type spinel [ 27 ], corroborated by Al2pNi3p XPS spectrum (Supplementary Fig. S4). Upon reduction at 700 ºC, an additional peak at 852.1 eV could be observed, ascribed to Ni 0 [ 28 ]. The Ni 2p3/2 peak has three contributions assigned to \(\:{\text{N}\text{i}}_{\text{O}\text{h}}^{2+}\) that strongly interacts with nearby Al 3+ ; \(\:{\text{N}\text{i}}_{\text{T}\text{h}}^{2+}\) that weakly interact with nearby Al 3+ ; and Ni 0 [ 29 ]. Reduction disrupts cationic nickel distribution, with \(\:{\text{N}\text{i}}_{\text{T}\text{h}}^{2+}\) / \(\:{\text{N}\text{i}}_{\text{O}\text{h}}^{2+}\) dropping from 0.7 to 0.1, indicating Ni migration from tetrahedral sites to metallic nanoparticles [ 29 ]. Three nickel species were detected based on their reduction temperature, namely NiO weakly interacting with Al, Ni 2+ in a nickel-deficient Ni 1−x Al 2 O 4−x spinel, and Ni 2+ in stoichiometric NiAl 2 O 4 [ 30 ]. The H 2 -TPR profile (Fig. 2 d) indicates incomplete nickel reduction. H 2 -TPD (Fig. 2 e) shows stronger hydrogen binding on HTC-600 (desorption at 136°C vs. 103°C), linked to enhanced activation on smaller Ni 0 particles (Supplementary Table S1 ). The high-temperature peak (~ 500°C) in HTC-600, absent in NiAl, corresponds to spillover hydrogen species active in hydrogenation [ 31 ]. Pyridine-FTIR (Supplementary Fig. S5, Table S2 ) shows only Lewis acid sites in NiAl and HTC-600. NiAl’s total acidity per gram is fourfold lower, but both have similar acid-site density (~ 0.52–0.57 sites/nm 2 ) dominated by weak (∼60%) and medium (27–39%) strength sites. XANES of NiAl shows both N 0 and Ni 2+ , with a strong white line ~ 2.5 eV above Ni 0 edge (peak D) characteristic of NiAl 2 O 4 (Fig. 2 b). HTC-600 spectra more closely resemble Ni 0 . A slight decrease in NiAl peak A reflects weak p–d hybridization typical of octahedral NiAl 2 O 4 /NiO coordination [ 32 ]. HTC-600’s white line shape and position (peak D) indicate a mix of NiO, NiAl 2 O 4 , and Ni 0 phases. Fourier-transformed EXAFS (Fig. 2 c) shows a strong Ni–Ni peak at ~ 2.2 Å, indicating Ni clustering and substantial metallic Ni in reduced catalysts. The average Ni coordination number (7.1–7.2) supports coexistence of Ni 2+ and Ni 0 (Supplementary Table S3). Weak oxygen backscattering (1–2 Å) reflects oxidized structure, aligning NiAl with NiAl 2 O 4 and HTC-600 with Ni 0 (peak A’, Fig. 2 c). O coordination numbers in NiAl and HTC-600 correspond to 0.3 and 0.13 of octahedral geometry, reflecting HTC-600’s higher metal site density (1.79 vs. 0.49 sites/nm 2 , Supplementary Table S1 ). This indicates smaller Ni 0 nanoparticles on HTC-600 (4.1 nm) versus larger clusters on NiAl (11.8 nm). TEM (Supplementary Fig. S6a) shows lattice fringes of Ni 0 (111), (200), and Ni-defective Ni 1 − X Al 2 O 4 − X spinel (311), (220), (111) facets. HAADF-STEM (Fig. S6b) reveals Ni particles 7–15 nm, matching XRD average of 12 nm (Supplementary Table S1 ). SEM (Fig. S6c) shows ~ 40 µm irregular particles with smooth surfaces; elemental mapping (Fig. S6d) confirms uniform Ni distribution. HTC-600 HAADF-STEM (Supplementary Fig. S7) shows smaller, uniform Ni particles (~ 4.1 nm), undetected by XRD. The impact of Ni local structure on isoeugenol HDO is discussed below. 3.2. Influence of reaction conditions on HDO selectivity Isoeugenol (IE) HDO was conducted in a batch reactor with NiAl at 250–300°C and 20–40 bar H 2 . Repeatability at 275°C, 30 bar (Supplementary Fig. S8) showed highly consistent DH conversion profiles with < 0.1% standard error after 60 minutes. The proposed pathway (Fig. 1 a) is based on GC-MS–identified products, including cracking byproducts. Rapid IE hydrogenation to DH [ 24 ] directed focus to DH conversion profiles. As shown in Fig. 3 a,b, DH fully converts within 30–120 minutes, with temperature and H 2 pressure accelerating conversion and altering selectivity. DH undergoes acid-catalyzed demethoxylation [ 33 ] to 4-propylphenol [ 34 ] (Fig. 1 a), which was not detected, implying rapid conversion to propylcyclohexanol (PCHol) or propylbenzene (PB) [ 34 ]. At 250°C, no PB formed (Fig. 3 c–h), indicating benzene ring hydrogenation is favored by higher hydrogen solubility. The activation energy for PB formation is three-fold higher than for PCHol (207 vs. 77 kJ/mol), indicating dehydroxylation (step 3) requires more energy than ring hydrogenation (steps 4–5) [ 35 , 36 ]. PB formation rates were consistently lower. Increasing H 2 pressure (Fig. 3 f–h) favored PCHol via hydrogenation–dehydroxylation, with PB becoming nearly undetectable at 40 bar (Fig. 3 h). The formation of intermediates (Supplementary Fig. S9) indicates that temperature strongly promotes PCHol dehydroxylation, with full conversion to PCH achieved at ≥ 275°C, while negligible dehydroxylation occurs at 250°C. In contrast, pressure showed minimal effect on the reaction rate ratio. At 275°C and 20 bar H 2 , prolonged reaction (Table 1 ) maximized PB yield (15.7 wt% at 180 min) and PCH yield (29.8 wt%). This performance surpasses previous studies, which reported only trace PB under similar conditions (Fig. 1 b). 3.3. Characterization of the spent catalyst NiAl used at 275°C and 30 bar H 2 was characterized post-reaction. S BET decreased by 28% with smaller pores (Supplementary Table S1 , Fig. S10), while the spinel structure remained stable (Supplementary Fig. S1 ). Ni 0 crystallites shrank from 12.0 to 8.2 nm. Raman (Supplementary Fig. S3b) showed D and G bands (I D /I G = 1.22), indicating low-order carbon, consistent with XRD absence of graphitic peaks. Coke deposition was low (80 µmol C /g cat ; ~0.1 wt.%, Supplementary Fig. S1 1), confirming NiAl’s coke resistance in isoeugenol HDO. 3.4. HDO performance of NiAl against benchmark HTC-600 catalyst HDO performance vs. normalized time (time × g Ni ) for NiAl and HTC-600 is shown in Supplementary Fig. S12a,b and Table 1 . DH conversion was much faster over HTC-600, with a 56-fold higher initial rate, but no PB was formed, indicating superior hydrogenation activity (step 4, Fig. 1 a). Table 1. Isoeugenol hydrodeoxygenation results using NiAl catalyst at maximum yield of PB (entries 1-5) and the benchmark HTC-600 catalyst (entry 6). Entry Conditions Yields (wt%) DH conversion (%) Time (min) Carbon Balance (%) T (°C) P (bar) PCHol PB PCH 1 * 250 30 45.8 0.0 14.8 100 240 77.0 2 275 30 24.7 5.6 23.9 100 60 61.7 3 300 30 13.2 6.2 29.3 100 30 66.8 4 275 20 4.8 15.7 29.9 100 180 62.2 5 275 40 28.6 1.3 22.0 100 30 59.4 6 275 30 7.7 0.0 64.7 100 60 67.4 * Given at 240 min reaction since no PB was detected at any time. Reactions conditions: isoeugenol (0.1 g), catalyst (0.05 g), dodecane (50 mL), 275 °C, 30 bar H 2 ; reaction mixture stirred at 900 rpm Cracking products (decane to hexane) formed mainly at higher temperature and pressure. While acidity promotes HDO, it also enhances cracking, lowering carbon balance (CB) [ 24 ]. For NiAl, CB decreased with temperature (Table 1 , entries #2–5) due to light alkanes and CO/CO 2 formation, yielding overall CB values of 60–77%, comparable to HTC-600. 3.5. Structure-activity correlation NiAl’s bifunctional nature yielded 2–30% PB and 38–59% PCH, within SAF specifications (Table 1 , Fig. 3 ). HTC-600 showed no PB, likely due to rapid hydrogenation. While weak-to-intermediate acidity promotes demethoxylation [ 37 ], similar acid-site densities in both catalysts do not account for the selectivity differences. NiAl’s balanced combination of medium-sized Ni 0 crystallites (61 at.% Ni 0 , 39 at.% Ni 2+ ) and weak-to-medium Lewis acid sites delivered optimal hydrogenation performance. Small clusters enhance methoxylation of lignin [ 38 ] and guaiacol [ 37 ], as edge and corner sites may favor aromatic ring activation over terrace sites [ 11 , 14 ]. We hypothesize that high reduction temperatures strengthen metal–support interactions in NiAl, modifying metal electronic properties and hydrogen activation. Spinel reduction generates unique interfaces with diverse Ni coordination and electronic structures. This complexity (broader H 2 -TPD peaks, coexisting Ni⁰/Ni 2+ ) governs metal dispersion and acidity, steering selectivity toward SAF-range products. This study is the first to demonstrate that a nickel aluminate spinel-derived catalyst can directly achieve SAF-compliant blends of aromatics and cycloalkanes from isoeugenol under mild reaction conditions, overcoming the long-standing challenge of balancing hydrogenation and deoxygenation pathways in lignin-derived bio-oil upgrading. 4. Conclusions This study provides the first demonstration that fine-tuning metal-support interactions in nickel aluminate spinel catalysts enables the direct, one-pot conversion of lignin-derived isoeugenol into SAF-compliant mixtures of aromatics and cycloalkanes under mild reaction conditions. The superior hydrodeoxygenation performance stems from the synergistic combination of medium-sized nickel crystallites and a moderate density of Lewis acid sites, which together suppress overhydrogenation − commonly observed in commercial catalysts with smaller nickel crystallites − and promote balanced product selectivity. The resulting fuel-grade product mixture is readily separable, and directly compatible with aviation fuel standards without requiring further processing. These findings address a long-standing challenge in biomass valorization and offer a scalable, practical catalytic route for sustainable aviation fuel production from lignin-derived feedstocks. Declarations Acknowledgements The authors gratefully acknowledge the technical and human support provided by SGIker (UPV/EHU/ERDF, EU) and by the National Facility ELECMI ICTS, node “Advanced Microscopy Laboratory” at the University of Zaragoza. The authors also thank DESY (Hamburg, Germany), a member of the Helmholtz Association (HGF), for providing access to experimental facilities. Parts of this research were conducted at the PETRA III light source at DESY, and the authors especially acknowledge Dr. Edmund Welter for his valuable assistance at beamline P65. Beamtime was allocated under proposal II-20230692. Funding The authors express their gratitude to MICIU/AEI/10.13039/501100011033 for PID2022-137146OB-I00 and PRE2020-094391 grants. Competing Interests The authors report no declarations of interest. Ethics approval Not applicable. Data Availability Data that support the findings of this study are available within the article (and its Supplementary Information files) and from the corresponding authors on reasonable request. Author contributions DGG designed and carried out the synthesis, characterizations and catalytic reactions, analyzed the data and wrote the manuscript. MEMK helped carried out the catalytic reactions, analyzed the data and wrote the manuscript. PMA supervised the project, assisted in regulating the experiments, discussion and wrote the manuscript. UIV analyzed the data and wrote the manuscript. MAGO supervised the project, analyzed the data. JLA and DYM supervised the project, helped design the experiments, analyzed the data and wrote the manuscript. References Undavalli V, Olatunde OBG, Boylu R et al (2023) Recent advancements in sustainable aviation fuels. Prog Aerosp Sci 136:100876 Holladay J, Abdullah Z, Heyne J (2020) Sustainable Aviation Fuel: Review of Technical Pathways. U.S. Department of Energy, Bioenergy Technologies Office ASTM D7566-22 (2023) Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons. ASTM International, West Conshohocken, PA ASTM D1655-22a (2023) Standard Specification for Aviation Turbine Fuels. ASTM International, West Conshohocken, PA Zakzeski J, Bruijnincx PCA, Jongerius AL, Weckhuysen BM (2010) The Catalytic Valorization of Lignin for the Production of Renewable Chemicals. Chem Rev 110:3552–3599 Webber MS, Watson J, Zhu J et al (2024) Lignin deoxygenation for the production of sustainable aviation fuel blendstocks. Nat Mater 23:1622–1638 Mäki-Arvela P, Murzin DY (2017) Hydrodeoxygenation of Lignin-Derived Phenols: From Fundamental Studies towards Industrial Applications. Catalysts 7(9):265 Martinez-Klimov M, Mäki-Arvela P, Çiftçi A et al (2022) Bifunctional Pt–Re Catalysts in Hydrodeoxygenation of Isoeugenol as a Model Compound for Renewable Jet Fuel Production. ACS Eng Au 2:436–449 Shomal R, Zheng Y (2023) Development of Processes and Catalysts for Biomass to Hydrocarbons at Moderate Conditions: A Comprehensive Review. Nanomaterials 13:2845 Wang X, Arai M, Wu Q, Zhang C, Zhao F (2020) Hydrodeoxygenation of lignin-derived phenolics- a review on the active sites of supported metal catalysts. Green Chem 22:8140–8168 Martinez-Klimov M, Mäki-Arvela P, Vajglova Z et al (2021) Hydrodeoxygenation of Isoeugenol over Carbon-Supported Pt and Pt–Re Catalysts for Production of Renewable Jet Fuel. Energy Fuels 35:17755–17768 Martínez-Klimov M, Yevdokimova O, Mäki-Arvela P et al (2024) Hydrodeoxygenation of isoeugenol in continuous mode using bifunctional Pt-Beta 25-binder catalysts for renewable jet fuel production. Sust Energ Fuels 8:90–102 Ghampson IT, Sepúlveda C, García R, Fierro JL, Escalona N (2016) Carbon nanofiber-supported ReOx catalysts for the hydrodeoxygenation of lignin-derived compounds. Catal Sci Technol 6:4356–4369 Alda-Onggar M, Mäki-Arvela P, Eränen K et al (2018) Hydrodeoxygenation of Isoeugenol over Alumina-Supported Ir, Pt, and Re Catalysts. ACS Sustainable Chem Eng 6:16205–16218 Guo Y, Zhang YW (2018) Metal Clusters Dispersed on Oxide Supports: Preparation Methods and Metal-Support Interactions. Top Catal 61:855–874 Baker LR, Kennedy G, van Spronsen M et al (2012) Furfuraldehyde Hydrogenation on Titanium Oxide-Supported Platinum Nanoparticles Studied by Sum Frequency Generation Vibrational Spectroscopy: Acid–Base Catalysis Explains the Molecular Origin of Strong Metal–Support Interactions. J Am Chem Soc 134:14208–14216 Van Deelen TW, Hernández-Mejía C, de Jong KP (2019) Control of metal-support interactions in heterogeneous catalysts to enhance activity and selectivity. Nat Catal 2:955–970 Li X, Zhang J, Liu B et al (2019) Hydrodeoxygenation of lignin-derived phenols to produce hydrocarbons over Ni/Al-SBA-15 prepared with different impregnants. Fuel 243:314–321 Li Z, Li Z, Wu M et al (2024) Selective hydrodeoxygenation of lignin-derived eugenol to propylcyclohexane over triazine polymer derived Co/NC-T catalyst. Mol Catal 557:113987 Bjelíc A, Grilc M, Huš M, Likozar B Hydrogenation and hydrodeoxygenation of aromatic lignin monomers over Cu/C, Ni C, Pd C, Pt C (2019) Rh/C and Ru/C catalysts: Mechanisms, reaction micro-kinetic modelling and quantitative structure-activity relationships. Chem Eng J 359:305–320 Meng-Yuan C, Yao-Bing H, Pang H, Xin-Xin L, Fu Y (2015) Hydrodeoxygenation of lignin-derived phenols into alkanes over carbon nanotube supported Ru catalysts in biphasic systems. Green Chem 17:1710–1717 Li S, Liu B, Truong J et al (2020) One-pot hydrodeoxygenation (HDO) of lignin monomers to C9 hydrocarbons co-catalyzed by Ru/C and Nb 2 O 5 . Green Chem 22:7406–7416 Yohe SL, Choudhary HJ, Metha DD et al (2016) High-pressure vapor-phase hydrodeoxygenation of lignin-derived oxygenates to hydrocarbons by a PtMo bimetallic catalyst: Product selectivity, reaction pathway, and structural characterization. J Catal 344:535–552 Tieuli S, Mäki-Arvela P, Purla M et al (2019) Hydrodeoxygenation of isoeugenol over Ni-SBA-15: Kinetics and modelling. Appl Catal A-Gen 580:1–10 Vajglová Z, Gauli B, Mäki-Arvela P et al (2023) Co-processing of fossil feedstock with lignin-derived model compound isoeugenol over Fe-Ni/H-Y-5.1 catalysts. J Catal 421:101–116 Vajglová Z, Yevdokimova O, Medina A et al (2023) Solventless hydrodeoxygenation of isoeugenol and dihydroeugenol in batch and continuous modes over a zeolite-supported FeNi catalyst. Sustain Energ Fuels 7:4486–4504 Li Z, Xueguang W, Xingfu S et al (2017) Carbon dioxide reforming of methane over mesoporous nickel aluminate/γ-alumina composites. J Energy Chem 26:93–100 Yancheshmeh MS, Sahraei OA, Aissaoui M, Iliuta MC (2020) A novel synthesis of NiAl 2 O 4 spinel from a Ni-Al mixed-metal alkoxide as a highly efficient catalyst for hydrogen production by glycerol steam reforming. Appl Catal B-Environ 265:118535 Vance BC, Najmi S, Kots PA et al (2023) Structure-Property Relationships for Nickel Aluminate Catalysts in Polyethylene Hydrogenolysis with Low Methane Selectivity. JACS Au 3:2156–2165 Gallego-García D, Iriarte-Velasco U, Gutiérrez-Ortiz MA, Ayastuy JL (2024) Nickel aluminate spinel-derived catalysts for aqueous-phase hydrogenolysis of glycerol with in-situ hydrogen production: Effect of molybdenum doping. Appl Catal B-Environ 344:123671 Geng Y, Li H (2022) Hydrogen Spillover-Enhanced Heterogeneously Catalyzed Hydrodeoxygenation for Biomass Upgrading. Chemsuschem 15:e202102495 Kesavan JK, Luisetto I, Tuti S et al (2017) Ni supported on YSZ: XAS and XPS characterization and catalytic activity for CO 2 methanation. J Mater Sci 52:10331–10340 Yan P, Li MM, Kennedy E et al (2020) The role of acid and metal sites in hydrodeoxygenation of guaiacol over Ni/Beta catalysts. Catal Sci Technol 10:810–825 Lindfors C, Mäki-Arvela P, Paturi P et al (2019) Hydrogeoxygenation of Isoeugenol over Ni- and Co-Supported Catalysts. ACS Sustainable Chem Eng 7:14545–14560 Toppinen S, Rantakylä TK, Salmi T, Aittamaa J (1996) Kinetics of the Liquid-Phase Hydrogenation of Benzene and Some Monosubstituted Alkylbenzenes over a Nickel Catalyst. Ind Eng Chem Res 35:1824–1833 Murzin DY, Sokolova NA, Kul’kova NV, Temkin MI (1989) Kinetics of liquid-phase hydrogenation of benzene and toluene on a nickel catalyst. Kinet Catal 30:1352 Yang H, Ying W, Zhu X, Deuss PJ, Heeres HJ (2022) Selective Demethoxylation of Guaiacols to Phenols using Supported MoO3 Catalysts. ChemCatChem 14:e202200297 Luo B, Zhu Z, Liang X et al (2023) Effect of metal site influenced by metal particle size on the catalytic hydrogenolysis of cornstalk lignin. J Energy Inst 109:101255 Supplementary Files SupplementaryInformation.docx Cite Share Download PDF Status: Published Journal Publication published 28 Jan, 2026 Read the published version in Environmental Chemistry Letters → Version 1 posted Reviewers agreed at journal 13 Jul, 2025 Reviewers invited by journal 13 Jul, 2025 Editor assigned by journal 19 Jun, 2025 First submitted to journal 18 Jun, 2025 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-6922102","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":484625430,"identity":"07e86878-7660-46ea-84d0-59e7918cec85","order_by":0,"name":"Daniel Gallego-García","email":"","orcid":"","institution":"University of the Basque Country: Universidad del Pais Vasco","correspondingAuthor":false,"prefix":"","firstName":"Daniel","middleName":"","lastName":"Gallego-García","suffix":""},{"id":484625431,"identity":"1cb9c75f-1f68-461b-87ee-84aecbf54c72","order_by":1,"name":"Mark E. Martínez-Klimov","email":"","orcid":"","institution":"Abo Akademi University: Abo Akademi","correspondingAuthor":false,"prefix":"","firstName":"Mark","middleName":"E.","lastName":"Martínez-Klimov","suffix":""},{"id":484625432,"identity":"23394c6b-53ba-4f1b-8614-7082c96a4850","order_by":2,"name":"Päivi Mäki-Arvela","email":"","orcid":"","institution":"Abo Akademi University: Abo Akademi","correspondingAuthor":false,"prefix":"","firstName":"Päivi","middleName":"","lastName":"Mäki-Arvela","suffix":""},{"id":484625433,"identity":"27011856-87fe-4486-9ccf-b354bb2452e9","order_by":3,"name":"Johan Wärnå","email":"","orcid":"","institution":"Abo Akademi University: Abo Akademi","correspondingAuthor":false,"prefix":"","firstName":"Johan","middleName":"","lastName":"Wärnå","suffix":""},{"id":484625434,"identity":"34f31d73-8d45-4901-a510-88999c99c69b","order_by":4,"name":"Unai Iriarte-Velasco","email":"","orcid":"","institution":"University of the Basque Country: Universidad del Pais Vasco","correspondingAuthor":false,"prefix":"","firstName":"Unai","middleName":"","lastName":"Iriarte-Velasco","suffix":""},{"id":484625435,"identity":"683b59af-eb1d-4ce1-84ee-72ef320b7df5","order_by":5,"name":"Miguel Angel Gutiérrez-Ortiz","email":"","orcid":"","institution":"University of the Basque Country: Universidad del Pais Vasco","correspondingAuthor":false,"prefix":"","firstName":"Miguel","middleName":"Angel","lastName":"Gutiérrez-Ortiz","suffix":""},{"id":484625436,"identity":"9d76a443-b59e-4abf-8c4a-9f53c357ab76","order_by":6,"name":"Jose Luis Ayastuy","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABD0lEQVRIiWNgGAWjYBACxgYg8YBBAiHCz8BDhJYEuJYEBgbJBgJaYAoRLIMDBLQwt7c/fJDYZmHPwH7G8OPPH4cTNx/vPSbBUHHYHqfDes4YGyS2SSQ28OQYS/MkHE7cduZcmgTDmcOJDbi0zMhhkwBqAboox0CaAaTlRo6ZBGPb4QQcOoBa0p//AGqxZ+B/Y/zzB1DL5vlvgFr+4XHYjAQzBqAWxgYJoOEgh22Q4AFqaTjMiNNhQL9IJJwDue1ZmTVPWrrxjDM5xhYJx9Jx+sUQGGIfPpTV2fPzJ2+++cPGWra//YzhjQ811jgdZggzi42BwwBEO4IFcPodCOQRTPYHIBKn4aNgFIyCUTByAQD4Nlgz6s8K5wAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-2770-5233","institution":"University of the Basque Country: Universidad del Pais Vasco","correspondingAuthor":true,"prefix":"","firstName":"Jose","middleName":"Luis","lastName":"Ayastuy","suffix":""},{"id":484625437,"identity":"514f8e3a-9113-4125-b11b-aa320a98771e","order_by":7,"name":"Dmitry Yu. Murzin","email":"","orcid":"","institution":"Abo Akademi University: Abo Akademi","correspondingAuthor":false,"prefix":"","firstName":"Dmitry","middleName":"Yu.","lastName":"Murzin","suffix":""}],"badges":[],"createdAt":"2025-06-18 10:37:37","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6922102/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6922102/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10311-026-01896-1","type":"published","date":"2026-01-28T15:59:22+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":86776463,"identity":"dd3f9f5a-9822-46e3-bb01-fbfd4c4bb591","added_by":"auto","created_at":"2025-07-15 12:44:32","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":428374,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea\u003c/strong\u003e Overall reaction network for HDO of isoeugenol. \u003cstrong\u003eb \u003c/strong\u003eComparison of yields to main products\u003cstrong\u003e \u003c/strong\u003ein the catalytic HDO of isoeugenol and similar substrates eugenol and dihydroeugenol at 100% substrate conversion.\u003cstrong\u003e c\u003c/strong\u003e Boiling temperatures of the typical liquid products of isoeugenol HDO over NiAl catalyst.\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-6922102/v1/0d5d2488fad769702771f636.png"},{"id":86775689,"identity":"d5e48c5d-3424-43bc-8ca9-7f5cb1612749","added_by":"auto","created_at":"2025-07-15 12:36:32","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":160543,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea\u003c/strong\u003e XPS spectra of the Ni 2p3/2 from NiAl catalyst. \u003cstrong\u003eb\u003c/strong\u003e Normalized Ni K edge XANES spectra of the reduced NiAl and HTC-600. \u003cstrong\u003ec\u003c/strong\u003e Fourier transformed (FT) k\u003csup\u003e2\u003c/sup\u003e-weighted Ni K edge EXAFS spectra of the reduced NiAl and HTC-600 catalysts. \u003cstrong\u003ed\u003c/strong\u003e H\u003csub\u003e2\u003c/sub\u003e-TPR profile of the fresh NiAl catalyst. \u003cstrong\u003ee\u003c/strong\u003e Area-normalized H\u003csub\u003e2\u003c/sub\u003e-TPD of NiAl and HTC-600 catalysts. The NiAl catalyst contains both metallic Ni and Ni²⁺, unlike HTC-600, which has only metallic Ni and higher hydrogen adsorption and activation capacity.\u003c/p\u003e","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-6922102/v1/86b377c899fc7b0de4e34e64.png"},{"id":86778665,"identity":"b35a10e5-6098-40e0-a3c6-5a66602f9ade","added_by":"auto","created_at":"2025-07-15 13:00:32","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":394288,"visible":true,"origin":"","legend":"\u003cp\u003eDihydroeugenol conversion as a function of time. \u003cstrong\u003ea\u003c/strong\u003e At different temperatures and 30 bar H\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003eb\u003c/strong\u003e At different pressures and 275 °C. Yield to different products as a function of time\u003cstrong\u003e (c, d, e)\u003c/strong\u003e Temperature effect analysis at 30 bar H\u003csub\u003e2\u003c/sub\u003e. \u003cstrong\u003e(f, g, h)\u003c/strong\u003e Pressure effect analysis at 275 ºC.\u003c/p\u003e","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-6922102/v1/e8a8a0291711a3fdd97f5ff3.png"},{"id":101690768,"identity":"2bba179d-6ebe-4bc9-8974-13223088f106","added_by":"auto","created_at":"2026-02-02 16:08:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1897888,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6922102/v1/4b2e2103-b0be-4d50-8fb9-e34fbdad344c.pdf"},{"id":86777725,"identity":"e0766f8c-b374-4ab0-b30c-1436b70131fb","added_by":"auto","created_at":"2025-07-15 12:52:32","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":4954884,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-6922102/v1/696433144a9f9b728377642b.docx"}],"financialInterests":"","formattedTitle":"Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eEnvironmental regulations have boosted global renewable demand across sectors, including aviation. Sustainable aviation fuels (SAFs), derived from renewable biomass, offer a pathway to cut global carbon emissions by up to 80% when fully replacing conventional jet fuel [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. SAF requires a complex blend of hydrocarbons, typically comprising n-alkanes (15\u0026ndash;25%), iso-alkanes (20\u0026ndash;55%), cyclo-alkanes (20\u0026ndash;45%) and aromatics (4\u0026ndash;25%) (in wt%) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Despite several ASTM-certified production pathways for SAFs [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], most of them lack the sufficient aromatic content. Developing a biomass pathway that directly yields SAFs with suitable aromatics would be a major advance.\u003c/p\u003e\u003cp\u003eIsoeugenol, a representative lignin-derived bio-oil model [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], is central to catalytic HDO for upgrading bio-oils to aviation-grade hydrocarbons [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Preserving isoeugenol\u0026rsquo;s aromatic structure is key to meeting SAF specifications. In the global reaction network for isoeugenol HDO (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea), propylbenzene (PB) is the key product for the SAFs application. Effective HDO catalysts are bifunctional: metal sites activate H\u003csub\u003e2\u003c/sub\u003e for hydrogenation/dehydrogenation [\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], while acid sites or oxygen vacancies promote dehydration and C\u0026ndash;O cleavage [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Balancing these sites is crucial to minimize over-hydrogenation and cracking, preserving fuel-range hydrocarbon yield.\u003c/p\u003e\u003cp\u003eEarly HDO of lignin-derived compounds used sulfided Mo-based catalysts, but their reliance on sulfiding agents limits practical application [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Noble metal catalysts have been studied for isoeugenol HDO (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], but over-hydrogenation lowers fuel-range yields, making transition metals (e.g. Ni, Co) a promising alternative. Isoeugenol HDO selectivity can be tuned via metal choice and support, as support acidity and metal\u0026ndash;support interactions influence dispersion, adsorption, and hydrogen activation [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Despite extensive studies on metals, supports, and feedstocks (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb), SAF-like product distributions with high selectivity for both aromatics and cycloalkanes remain unattainable [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eHere, we report a nickel aluminate spinel-derived catalyst (NiAl) with exceptional HDO performance, producing aromatics and cycloalkanes at SAF-specification yields, readily separable (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec), surpassing previous benchmarks.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cp\u003eExperimental details \u0026ndash;including catalyst synthesis, characterization, reaction procedures, product analysis, and metrics\u0026thinsp;\u0026minus;\u0026thinsp;are provided in the Supplementary Information.\u003c/p\u003e"},{"header":"3. Results and discussion","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Catalyst characterization\u003c/h2\u003e\u003cp\u003eResults for a commercial catalyst (HTC-600) with a Ni/Al composition similar to NiAl (Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e) are also presented and discussed. The NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e spinel structure of the NiAl precursor was confirmed by XRD, UV-Vis DRS and Raman spectroscopy (Supplementary Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e-S3).\u003c/p\u003e\u003cp\u003eThe Ni 2p3/2 XPS spectrum (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea) of calcined NiAl exhibited two main bands at \u0026sim;855.9 eV and \u0026sim;862.2 eV, characteristics of a NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e-type spinel [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], corroborated by Al2pNi3p XPS spectrum (Supplementary Fig. S4). Upon reduction at 700 \u0026ordm;C, an additional peak at 852.1 eV could be observed, ascribed to Ni\u003csup\u003e0\u003c/sup\u003e [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. The Ni 2p3/2 peak has three contributions assigned to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\text{N}\\text{i}}_{\\text{O}\\text{h}}^{2+}\\)\u003c/span\u003e\u003c/span\u003e that strongly interacts with nearby Al\u003csup\u003e3+\u003c/sup\u003e; \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\text{N}\\text{i}}_{\\text{T}\\text{h}}^{2+}\\)\u003c/span\u003e\u003c/span\u003e that weakly interact with nearby Al\u003csup\u003e3+\u003c/sup\u003e; and Ni\u003csup\u003e0\u003c/sup\u003e [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Reduction disrupts cationic nickel distribution, with \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\text{N}\\text{i}}_{\\text{T}\\text{h}}^{2+}\\)\u003c/span\u003e\u003c/span\u003e/\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\text{N}\\text{i}}_{\\text{O}\\text{h}}^{2+}\\)\u003c/span\u003e\u003c/span\u003e dropping from 0.7 to 0.1, indicating Ni migration from tetrahedral sites to metallic nanoparticles [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Three nickel species were detected based on their reduction temperature, namely NiO weakly interacting with Al, Ni\u003csup\u003e2+\u003c/sup\u003e in a nickel-deficient Ni\u003csub\u003e1\u0026minus;x\u003c/sub\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u0026minus;x\u003c/sub\u003e spinel, and Ni\u003csup\u003e2+\u003c/sup\u003e in stoichiometric NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. The H\u003csub\u003e2\u003c/sub\u003e-TPR profile (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed) indicates incomplete nickel reduction.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eH\u003csub\u003e2\u003c/sub\u003e-TPD (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee) shows stronger hydrogen binding on HTC-600 (desorption at 136\u0026deg;C vs. 103\u0026deg;C), linked to enhanced activation on smaller Ni\u003csup\u003e0\u003c/sup\u003e particles (Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). The high-temperature peak (~\u0026thinsp;500\u0026deg;C) in HTC-600, absent in NiAl, corresponds to spillover hydrogen species active in hydrogenation [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e\u003cp\u003ePyridine-FTIR (Supplementary Fig. S5, Table \u003cspan refid=\"MOESM2\" class=\"InternalRef\"\u003eS2\u003c/span\u003e) shows only Lewis acid sites in NiAl and HTC-600. NiAl\u0026rsquo;s total acidity per gram is fourfold lower, but both have similar acid-site density (~\u0026thinsp;0.52\u0026ndash;0.57 sites/nm\u003csup\u003e2\u003c/sup\u003e) dominated by weak (\u0026sim;60%) and medium (27\u0026ndash;39%) strength sites.\u003c/p\u003e\u003cp\u003eXANES of NiAl shows both N\u003csup\u003e0\u003c/sup\u003e and Ni\u003csup\u003e2+\u003c/sup\u003e, with a strong white line\u0026thinsp;~\u0026thinsp;2.5 eV above Ni\u003csup\u003e0\u003c/sup\u003e edge (peak D) characteristic of NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). HTC-600 spectra more closely resemble Ni\u003csup\u003e0\u003c/sup\u003e. A slight decrease in NiAl peak A reflects weak p\u0026ndash;d hybridization typical of octahedral NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e/NiO coordination [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. HTC-600\u0026rsquo;s white line shape and position (peak D) indicate a mix of NiO, NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e, and Ni\u003csup\u003e0\u003c/sup\u003e phases.\u003c/p\u003e\u003cp\u003eFourier-transformed EXAFS (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec) shows a strong Ni\u0026ndash;Ni peak at ~\u0026thinsp;2.2 \u0026Aring;, indicating Ni clustering and substantial metallic Ni in reduced catalysts. The average Ni coordination number (7.1\u0026ndash;7.2) supports coexistence of Ni\u003csup\u003e2+\u003c/sup\u003e and Ni\u003csup\u003e0\u003c/sup\u003e (Supplementary Table S3). Weak oxygen backscattering (1\u0026ndash;2 \u0026Aring;) reflects oxidized structure, aligning NiAl with NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e and HTC-600 with Ni\u003csup\u003e0\u003c/sup\u003e (peak A\u0026rsquo;, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). O coordination numbers in NiAl and HTC-600 correspond to 0.3 and 0.13 of octahedral geometry, reflecting HTC-600\u0026rsquo;s higher metal site density (1.79 vs. 0.49 sites/nm\u003csup\u003e2\u003c/sup\u003e, Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). This indicates smaller Ni\u003csup\u003e0\u003c/sup\u003e nanoparticles on HTC-600 (4.1 nm) versus larger clusters on NiAl (11.8 nm).\u003c/p\u003e\u003cp\u003eTEM (Supplementary Fig. S6a) shows lattice fringes of Ni\u003csup\u003e0\u003c/sup\u003e (111), (200), and Ni-defective Ni\u003csub\u003e1\u0026thinsp;\u0026minus;\u0026thinsp;X\u003c/sub\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u0026thinsp;\u0026minus;\u0026thinsp;X\u003c/sub\u003e spinel (311), (220), (111) facets. HAADF-STEM (Fig. S6b) reveals Ni particles 7\u0026ndash;15 nm, matching XRD average of 12 nm (Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). SEM (Fig. S6c) shows\u0026thinsp;~\u0026thinsp;40 \u0026micro;m irregular particles with smooth surfaces; elemental mapping (Fig. S6d) confirms uniform Ni distribution. HTC-600 HAADF-STEM (Supplementary Fig. S7) shows smaller, uniform Ni particles (~\u0026thinsp;4.1 nm), undetected by XRD.\u003c/p\u003e\u003cp\u003eThe impact of Ni local structure on isoeugenol HDO is discussed below.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Influence of reaction conditions on HDO selectivity\u003c/h2\u003e\u003cp\u003eIsoeugenol (IE) HDO was conducted in a batch reactor with NiAl at 250\u0026ndash;300\u0026deg;C and 20\u0026ndash;40 bar H\u003csub\u003e2\u003c/sub\u003e. Repeatability at 275\u0026deg;C, 30 bar (Supplementary Fig. S8) showed highly consistent DH conversion profiles with \u0026lt;\u0026thinsp;0.1% standard error after 60 minutes.\u003c/p\u003e\u003cp\u003eThe proposed pathway (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea) is based on GC-MS\u0026ndash;identified products, including cracking byproducts. Rapid IE hydrogenation to DH [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] directed focus to DH conversion profiles. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea,b, DH fully converts within 30\u0026ndash;120 minutes, with temperature and H\u003csub\u003e2\u003c/sub\u003e pressure accelerating conversion and altering selectivity.\u003c/p\u003e\u003cp\u003eDH undergoes acid-catalyzed demethoxylation [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] to 4-propylphenol [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea), which was not detected, implying rapid conversion to propylcyclohexanol (PCHol) or propylbenzene (PB) [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. At 250\u0026deg;C, no PB formed (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec\u0026ndash;h), indicating benzene ring hydrogenation is favored by higher hydrogen solubility. The activation energy for PB formation is three-fold higher than for PCHol (207 vs. 77 kJ/mol), indicating dehydroxylation (step 3) requires more energy than ring hydrogenation (steps 4\u0026ndash;5) [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. PB formation rates were consistently lower. Increasing H\u003csub\u003e2\u003c/sub\u003e pressure (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef\u0026ndash;h) favored PCHol via hydrogenation\u0026ndash;dehydroxylation, with PB becoming nearly undetectable at 40 bar (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eh). The formation of intermediates (Supplementary Fig. S9) indicates that temperature strongly promotes PCHol dehydroxylation, with full conversion to PCH achieved at \u0026ge;\u0026thinsp;275\u0026deg;C, while negligible dehydroxylation occurs at 250\u0026deg;C. In contrast, pressure showed minimal effect on the reaction rate ratio. At 275\u0026deg;C and 20 bar H\u003csub\u003e2\u003c/sub\u003e, prolonged reaction (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) maximized PB yield (15.7 wt% at 180 min) and PCH yield (29.8 wt%). This performance surpasses previous studies, which reported only trace PB under similar conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Characterization of the spent catalyst\u003c/h2\u003e\u003cp\u003eNiAl used at 275\u0026deg;C and 30 bar H\u003csub\u003e2\u003c/sub\u003e was characterized post-reaction. S\u003csub\u003eBET\u003c/sub\u003e decreased by 28% with smaller pores (Supplementary Table \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e, Fig. S10), while the spinel structure remained stable (Supplementary Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e). Ni\u003csup\u003e0\u003c/sup\u003e crystallites shrank from 12.0 to 8.2 nm. Raman (Supplementary Fig. S3b) showed D and G bands (I\u003csub\u003eD\u003c/sub\u003e/I\u003csub\u003eG\u003c/sub\u003e = 1.22), indicating low-order carbon, consistent with XRD absence of graphitic peaks. Coke deposition was low (80 \u0026micro;mol\u003csub\u003eC\u003c/sub\u003e/g\u003csub\u003ecat\u003c/sub\u003e; ~0.1 wt.%, Supplementary Fig. \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003e1), confirming NiAl\u0026rsquo;s coke resistance in isoeugenol HDO.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e3.4. HDO performance of NiAl against benchmark HTC-600 catalyst\u003c/h2\u003e\u003cp\u003eHDO performance vs. normalized time (time \u0026times; g\u003csub\u003eNi\u003c/sub\u003e) for NiAl and HTC-600 is shown in Supplementary Fig. S12a,b and Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. DH conversion was much faster over HTC-600, with a 56-fold higher initial rate, but no PB was formed, indicating superior hydrogenation activity (step 4, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e Isoeugenol hydrodeoxygenation results using NiAl catalyst at maximum yield of PB (entries 1-5) and the benchmark HTC-600 catalyst (entry 6).\u003c/p\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"647\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 58px;\"\u003e\n \u003cp\u003eEntry\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 124px;\"\u003e\n \u003cp\u003eConditions\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" style=\"width: 174px;\"\u003e\n \u003cp\u003eYields (wt%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 81px;\"\u003e\n \u003cp\u003eDH\u003c/p\u003e\n \u003cp\u003econversion\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 47px;\"\u003e\n \u003cp\u003eTime\u003c/p\u003e\n \u003cp\u003e(min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 76px;\"\u003e\n \u003cp\u003eCarbon\u003c/p\u003e\n \u003cp\u003eBalance\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003eT\u003c/p\u003e\n \u003cp\u003e(\u0026deg;C)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003cp\u003e(bar)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 61px;\"\u003e\n \u003cp\u003ePCHol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003ePB\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003ePCH\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e1 \u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e250\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e45.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e14.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e240\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e77.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e275\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e24.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e5.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e23.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e61.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e13.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e6.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e29.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e66.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e275\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e4.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e15.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e29.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e180\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e62.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e275\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e28.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e1.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e22.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e59.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 58px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 55px;\"\u003e\n \u003cp\u003e275\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 19px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003e7.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 47px;\"\u003e\n \u003cp\u003e64.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e67.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 68px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"11\" valign=\"top\" style=\"width: 647px;\"\u003e\n \u003cp\u003e\u003csup\u003e*\u003c/sup\u003e Given at 240 min reaction since no PB was detected at any time.\u003c/p\u003e\n \u003cp\u003eReactions conditions: isoeugenol (0.1 g), catalyst (0.05 g), dodecane (50 mL), 275 \u0026deg;C, 30 bar H\u003csub\u003e2\u003c/sub\u003e; reaction mixture stirred at 900 rpm\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\u003cbr\u003e\u003cp\u003eCracking products (decane to hexane) formed mainly at higher temperature and pressure. While acidity promotes HDO, it also enhances cracking, lowering carbon balance (CB) [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. For NiAl, CB decreased with temperature (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, entries #2\u0026ndash;5) due to light alkanes and CO/CO\u003csub\u003e2\u003c/sub\u003e formation, yielding overall CB values of 60\u0026ndash;77%, comparable to HTC-600.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.5. Structure-activity correlation\u003c/h2\u003e\u003cp\u003eNiAl\u0026rsquo;s bifunctional nature yielded 2\u0026ndash;30% PB and 38\u0026ndash;59% PCH, within SAF specifications (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). HTC-600 showed no PB, likely due to rapid hydrogenation. While weak-to-intermediate acidity promotes demethoxylation [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e], similar acid-site densities in both catalysts do not account for the selectivity differences.\u003c/p\u003e\u003cp\u003eNiAl\u0026rsquo;s balanced combination of medium-sized Ni\u003csup\u003e0\u003c/sup\u003e crystallites (61 at.% Ni\u003csup\u003e0\u003c/sup\u003e, 39 at.% Ni\u003csup\u003e2+\u003c/sup\u003e) and weak-to-medium Lewis acid sites delivered optimal hydrogenation performance. Small clusters enhance methoxylation of lignin [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e] and guaiacol [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e], as edge and corner sites may favor aromatic ring activation over terrace sites [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. We hypothesize that high reduction temperatures strengthen metal\u0026ndash;support interactions in NiAl, modifying metal electronic properties and hydrogen activation. Spinel reduction generates unique interfaces with diverse Ni coordination and electronic structures. This complexity (broader H\u003csub\u003e2\u003c/sub\u003e-TPD peaks, coexisting Ni⁰/Ni\u003csup\u003e2+\u003c/sup\u003e) governs metal dispersion and acidity, steering selectivity toward SAF-range products.\u003c/p\u003e\u003cp\u003eThis study is the first to demonstrate that a nickel aluminate spinel-derived catalyst can directly achieve SAF-compliant blends of aromatics and cycloalkanes from isoeugenol under mild reaction conditions, overcoming the long-standing challenge of balancing hydrogenation and deoxygenation pathways in lignin-derived bio-oil upgrading.\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Conclusions","content":"\u003cp\u003eThis study provides the first demonstration that fine-tuning metal-support interactions in nickel aluminate spinel catalysts enables the direct, one-pot conversion of lignin-derived isoeugenol into SAF-compliant mixtures of aromatics and cycloalkanes under mild reaction conditions. The superior hydrodeoxygenation performance stems from the synergistic combination of medium-sized nickel crystallites and a moderate density of Lewis acid sites, which together suppress overhydrogenation\u0026thinsp;\u0026minus;\u0026thinsp;commonly observed in commercial catalysts with smaller nickel crystallites\u0026thinsp;\u0026minus;\u0026thinsp;and promote balanced product selectivity. The resulting fuel-grade product mixture is readily separable, and directly compatible with aviation fuel standards without requiring further processing. These findings address a long-standing challenge in biomass valorization and offer a scalable, practical catalytic route for sustainable aviation fuel production from lignin-derived feedstocks.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors gratefully acknowledge the technical and human support provided by SGIker (UPV/EHU/ERDF, EU) and by the National Facility ELECMI ICTS, node \u0026ldquo;Advanced Microscopy Laboratory\u0026rdquo; at the University of Zaragoza. The authors also thank DESY (Hamburg, Germany), a member of the Helmholtz Association (HGF), for providing access to experimental facilities. Parts of this research were conducted at the PETRA III light source at DESY, and the authors especially acknowledge Dr. Edmund Welter for his valuable assistance at beamline P65. Beamtime was allocated under proposal II-20230692.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors express their gratitude to MICIU/AEI/10.13039/501100011033 for PID2022-137146OB-I00 and PRE2020-094391 grants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors report no declarations of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData that support the findings of this study are available within the article (and its Supplementary Information files) and from the corresponding authors on reasonable request.\u003c/p\u003e\n\u003ch3\u003eAuthor contributions\u003c/h3\u003e\n\u003cp\u003eDGG designed and carried out the synthesis, characterizations and catalytic reactions, analyzed the data and wrote the manuscript. MEMK helped carried out the catalytic reactions, analyzed the data and wrote the manuscript. PMA supervised the project, assisted in regulating the experiments, discussion and wrote the manuscript. UIV analyzed the data and wrote the manuscript. MAGO supervised the project, analyzed the data. JLA and DYM supervised the project, helped design the experiments, analyzed the data and wrote the manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eUndavalli V, Olatunde OBG, Boylu R et al (2023) Recent advancements in sustainable aviation fuels. Prog Aerosp Sci 136:100876\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHolladay J, Abdullah Z, Heyne J (2020) Sustainable Aviation Fuel: Review of Technical Pathways. U.S. Department of Energy, Bioenergy Technologies Office\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eASTM D7566-22 (2023) Standard Specification for Aviation Turbine Fuel Containing Synthesized Hydrocarbons. ASTM International, West Conshohocken, PA\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eASTM D1655-22a (2023) Standard Specification for Aviation Turbine Fuels. ASTM International, West Conshohocken, PA\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZakzeski J, Bruijnincx PCA, Jongerius AL, Weckhuysen BM (2010) The Catalytic Valorization of Lignin for the Production of Renewable Chemicals. Chem Rev 110:3552\u0026ndash;3599\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWebber MS, Watson J, Zhu J et al (2024) Lignin deoxygenation for the production of sustainable aviation fuel blendstocks. Nat Mater 23:1622\u0026ndash;1638\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eM\u0026auml;ki-Arvela P, Murzin DY (2017) Hydrodeoxygenation of Lignin-Derived Phenols: From Fundamental Studies towards Industrial Applications. Catalysts 7(9):265\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartinez-Klimov M, M\u0026auml;ki-Arvela P, \u0026Ccedil;ift\u0026ccedil;i A et al (2022) Bifunctional Pt\u0026ndash;Re Catalysts in Hydrodeoxygenation of Isoeugenol as a Model Compound for Renewable Jet Fuel Production. ACS Eng Au 2:436\u0026ndash;449\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShomal R, Zheng Y (2023) Development of Processes and Catalysts for Biomass to Hydrocarbons at Moderate Conditions: A Comprehensive Review. Nanomaterials 13:2845\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang X, Arai M, Wu Q, Zhang C, Zhao F (2020) Hydrodeoxygenation of lignin-derived phenolics- a review on the active sites of supported metal catalysts. Green Chem 22:8140\u0026ndash;8168\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMartinez-Klimov M, M\u0026auml;ki-Arvela P, Vajglova Z et al (2021) Hydrodeoxygenation of Isoeugenol over Carbon-Supported Pt and Pt\u0026ndash;Re Catalysts for Production of Renewable Jet Fuel. Energy Fuels 35:17755\u0026ndash;17768\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMart\u0026iacute;nez-Klimov M, Yevdokimova O, M\u0026auml;ki-Arvela P et al (2024) Hydrodeoxygenation of isoeugenol in continuous mode using bifunctional Pt-Beta 25-binder catalysts for renewable jet fuel production. Sust Energ Fuels 8:90\u0026ndash;102\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGhampson IT, Sep\u0026uacute;lveda C, Garc\u0026iacute;a R, Fierro JL, Escalona N (2016) Carbon nanofiber-supported ReOx catalysts for the hydrodeoxygenation of lignin-derived compounds. Catal Sci Technol 6:4356\u0026ndash;4369\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAlda-Onggar M, M\u0026auml;ki-Arvela P, Er\u0026auml;nen K et al (2018) Hydrodeoxygenation of Isoeugenol over Alumina-Supported Ir, Pt, and Re Catalysts. ACS Sustainable Chem Eng 6:16205\u0026ndash;16218\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGuo Y, Zhang YW (2018) Metal Clusters Dispersed on Oxide Supports: Preparation Methods and Metal-Support Interactions. Top Catal 61:855\u0026ndash;874\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBaker LR, Kennedy G, van Spronsen M et al (2012) Furfuraldehyde Hydrogenation on Titanium Oxide-Supported Platinum Nanoparticles Studied by Sum Frequency Generation Vibrational Spectroscopy: Acid\u0026ndash;Base Catalysis Explains the Molecular Origin of Strong Metal\u0026ndash;Support Interactions. J Am Chem Soc 134:14208\u0026ndash;14216\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVan Deelen TW, Hern\u0026aacute;ndez-Mej\u0026iacute;a C, de Jong KP (2019) Control of metal-support interactions in heterogeneous catalysts to enhance activity and selectivity. Nat Catal 2:955\u0026ndash;970\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi X, Zhang J, Liu B et al (2019) Hydrodeoxygenation of lignin-derived phenols to produce hydrocarbons over Ni/Al-SBA-15 prepared with different impregnants. Fuel 243:314\u0026ndash;321\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Z, Li Z, Wu M et al (2024) Selective hydrodeoxygenation of lignin-derived eugenol to propylcyclohexane over triazine polymer derived Co/NC-T catalyst. Mol Catal 557:113987\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBjel\u0026iacute;c A, Grilc M, Huš M, Likozar B Hydrogenation and hydrodeoxygenation of aromatic lignin monomers over Cu/C, Ni C, Pd C, Pt C (2019) Rh/C and Ru/C catalysts: Mechanisms, reaction micro-kinetic modelling and quantitative structure-activity relationships. Chem Eng J 359:305\u0026ndash;320\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMeng-Yuan C, Yao-Bing H, Pang H, Xin-Xin L, Fu Y (2015) Hydrodeoxygenation of lignin-derived phenols into alkanes over carbon nanotube supported Ru catalysts in biphasic systems. Green Chem 17:1710\u0026ndash;1717\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi S, Liu B, Truong J et al (2020) One-pot hydrodeoxygenation (HDO) of lignin monomers to C9 hydrocarbons co-catalyzed by Ru/C and Nb\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e5\u003c/sub\u003e. Green Chem 22:7406\u0026ndash;7416\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYohe SL, Choudhary HJ, Metha DD et al (2016) High-pressure vapor-phase hydrodeoxygenation of lignin-derived oxygenates to hydrocarbons by a PtMo bimetallic catalyst: Product selectivity, reaction pathway, and structural characterization. J Catal 344:535\u0026ndash;552\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTieuli S, M\u0026auml;ki-Arvela P, Purla M et al (2019) Hydrodeoxygenation of isoeugenol over Ni-SBA-15: Kinetics and modelling. Appl Catal A-Gen 580:1\u0026ndash;10\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVajglov\u0026aacute; Z, Gauli B, M\u0026auml;ki-Arvela P et al (2023) Co-processing of fossil feedstock with lignin-derived model compound isoeugenol over Fe-Ni/H-Y-5.1 catalysts. J Catal 421:101\u0026ndash;116\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVajglov\u0026aacute; Z, Yevdokimova O, Medina A et al (2023) Solventless hydrodeoxygenation of isoeugenol and dihydroeugenol in batch and continuous modes over a zeolite-supported FeNi catalyst. Sustain Energ Fuels 7:4486\u0026ndash;4504\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi Z, Xueguang W, Xingfu S et al (2017) Carbon dioxide reforming of methane over mesoporous nickel aluminate/γ-alumina composites. J Energy Chem 26:93\u0026ndash;100\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYancheshmeh MS, Sahraei OA, Aissaoui M, Iliuta MC (2020) A novel synthesis of NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e spinel from a Ni-Al mixed-metal alkoxide as a highly efficient catalyst for hydrogen production by glycerol steam reforming. Appl Catal B-Environ 265:118535\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eVance BC, Najmi S, Kots PA et al (2023) Structure-Property Relationships for Nickel Aluminate Catalysts in Polyethylene Hydrogenolysis with Low Methane Selectivity. JACS Au 3:2156\u0026ndash;2165\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGallego-Garc\u0026iacute;a D, Iriarte-Velasco U, Guti\u0026eacute;rrez-Ortiz MA, Ayastuy JL (2024) Nickel aluminate spinel-derived catalysts for aqueous-phase hydrogenolysis of glycerol with in-situ hydrogen production: Effect of molybdenum doping. Appl Catal B-Environ 344:123671\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGeng Y, Li H (2022) Hydrogen Spillover-Enhanced Heterogeneously Catalyzed Hydrodeoxygenation for Biomass Upgrading. Chemsuschem 15:e202102495\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKesavan JK, Luisetto I, Tuti S et al (2017) Ni supported on YSZ: XAS and XPS characterization and catalytic activity for CO\u003csub\u003e2\u003c/sub\u003e methanation. J Mater Sci 52:10331\u0026ndash;10340\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYan P, Li MM, Kennedy E et al (2020) The role of acid and metal sites in hydrodeoxygenation of guaiacol over Ni/Beta catalysts. Catal Sci Technol 10:810\u0026ndash;825\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLindfors C, M\u0026auml;ki-Arvela P, Paturi P et al (2019) Hydrogeoxygenation of Isoeugenol over Ni- and Co-Supported Catalysts. ACS Sustainable Chem Eng 7:14545\u0026ndash;14560\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eToppinen S, Rantakyl\u0026auml; TK, Salmi T, Aittamaa J (1996) Kinetics of the Liquid-Phase Hydrogenation of Benzene and Some Monosubstituted Alkylbenzenes over a Nickel Catalyst. Ind Eng Chem Res 35:1824\u0026ndash;1833\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMurzin DY, Sokolova NA, Kul\u0026rsquo;kova NV, Temkin MI (1989) Kinetics of liquid-phase hydrogenation of benzene and toluene on a nickel catalyst. Kinet Catal 30:1352\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang H, Ying W, Zhu X, Deuss PJ, Heeres HJ (2022) Selective Demethoxylation of Guaiacols to Phenols using Supported MoO3 Catalysts. ChemCatChem 14:e202200297\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLuo B, Zhu Z, Liang X et al (2023) Effect of metal site influenced by metal particle size on the catalytic hydrogenolysis of cornstalk lignin. J Energy Inst 109:101255\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":"[email protected]","identity":"environmental-chemistry-letters","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ecle","sideBox":"Learn more about [Environmental Chemistry Letters](https://www.springer.com/journal/10311)","snPcode":"10311","submissionUrl":"https://submission.nature.com/new-submission/10311/3","title":"Environmental Chemistry Letters","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Hydrodeoxygenation, Biomass valorization: Isoeugenol, Nickel aluminate catalyst, Aromatic-cycloalkane fuel blend optimization, SAF","lastPublishedDoi":"10.21203/rs.3.rs-6922102/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6922102/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe efficient production of sustainable aviation fuels (SAFs) from lignin-derived biomass remains a major challenge due to the difficulty of simultaneously generating both aromatics and cycloalkanes in the specific ratios required by fuel specifications. In particular, hydrodeoxygenation (HDO) of isoeugenol involves competing pathways: full hydrogenation to produce cycloalkanes, and selective deoxygenation that preserves the aromatic ring. To date, no catalytic system has successfully combined high selectivity for both hydrocarbon classes under mild conditions.\u003c/p\u003e\u003cp\u003eHere, we demonstrate that a nickel aluminate spinel-derived catalyst, synthesized via a simple one-pot sol-gel method, overcomes this limitation by enabling, for the first time, the direct production of SAF-compatible blends with 16 wt% aromatics and 30 wt% cycloalkanes at 275\u0026deg;C and 20 bar H\u003csub\u003e2\u003c/sub\u003e. The superior selectivity arises from the tailored structural and surface properties of the spinel support, which balance hydrogenation and deoxygenation pathways. The catalyst exhibits excellent reproducibility, facile product separation, and scalability, offering a practical route for one-pot, large-scale SAF production from lignocellulosic feedstocks. This work addresses a key bottleneck in biomass valorization, representing a significant advance in catalyst design for renewable aviation fuels.\u003c/p\u003e","manuscriptTitle":"Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-15 12:36:27","doi":"10.21203/rs.3.rs-6922102/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2025-07-13T09:49:19+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-13T09:36:58+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-19T07:20:37+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Chemistry Letters","date":"2025-06-18T06:37:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-chemistry-letters","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ecle","sideBox":"Learn more about [Environmental Chemistry Letters](https://www.springer.com/journal/10311)","snPcode":"10311","submissionUrl":"https://submission.nature.com/new-submission/10311/3","title":"Environmental Chemistry Letters","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"41f9651b-8993-47f9-afc4-711931f9d341","owner":[],"postedDate":"July 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-02T16:05:23+00:00","versionOfRecord":{"articleIdentity":"rs-6922102","link":"https://doi.org/10.1007/s10311-026-01896-1","journal":{"identity":"environmental-chemistry-letters","isVorOnly":false,"title":"Environmental Chemistry Letters"},"publishedOn":"2026-01-28 15:59:22","publishedOnDateReadable":"January 28th, 2026"},"versionCreatedAt":"2025-07-15 12:36:27","video":"","vorDoi":"10.1007/s10311-026-01896-1","vorDoiUrl":"https://doi.org/10.1007/s10311-026-01896-1","workflowStages":[]},"version":"v1","identity":"rs-6922102","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6922102","identity":"rs-6922102","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}