Key Takeaways & Executive Findings
- •• • Air-calcined Cu/SiO2 (Cu/SiO2-A) achieved 92.37% DMS conversion and 64.15% BDO yield at 210 °C, 5.0 MPa, WHSV 0.6 h−1, H2/DMS molar ratio 100, demonstrating superior performance for industrial BDO production. • • Air calcination induced the strongest metal-support interaction, leading to highest copper dispersion and largest population of stabilized Cu+ species, which are critical for hydrogen activation and carbonyl adsorption. • • The catalyst exhibited abundant surface acidity, promoting C=O polarization and synergistic metal-acid cooperation, essential for selective hydrogenation to BDO. • • Calcination atmosphere engineering is a potent, cost-effective strategy to tune Cu/SiO2 catalysts, offering a scalable approach to optimize metal-support interactions for efficient hydrogenation processes.
Abstract
The catalytic hydrogenation of biomass-derived dimethyl succinate (DMS) to 1,4-butanediol (BDO) is a pivotal route for producing high-value C4 chemicals in green chemistry. Cu/SiO2 catalysts are known for high selectivity in hydrogenating ester groups, with performance correlated to copper species microstructure. Although calcination critically defines this active structure, systematic influence of calcination atmosphere remains underexplored. Here, Cu/SiO2 catalysts were prepared via urea-assisted hydrothermal method and calcined under different atmospheres to elucidate effects on physicochemical properties and hydrogenation performance. Comprehensive characterization (N2 physisorption, FT-IR, H2-TPR, XRD, TEM, N2O pulse chemisorption, XPS, NH3-TPD) revealed that calcination atmosphere profoundly alters metal-support interaction, regulating dispersion and chemical state of copper species. Specifically, air calcination promoted stronger metal-support interaction, enhancing copper dispersion and increasing proportion of key active Cu+ species. Consequently, air-calcined catalyst achieved 92.37% DMS conversion and 64.15% BDO yield under optimized conditions (210 °C, 5.0 MPa, WHSV 0.6 h−1, H2/DMS molar ratio 100). This work underscores calcination atmosphere engineering as potent strategy for optimizing metal-support interactions in heterogeneous catalysts for efficient hydrogenation.
1. Introduction
The catalytic hydrogenation of biomass-derived dimethyl succinate (DMS) to 1,4-butanediol (BDO) is a cornerstone of sustainable chemical production, yet commercial viability hinges on catalyst performance. Conventional Cu/SiO2 catalysts suffer from inadequate dispersion and unstable active species, leading to suboptimal conversion and selectivity. The bottleneck lies in precisely controlling the metal-support interaction during synthesis, particularly the calcination step, which remains underexplored.
This study addresses this gap by systematically engineering the calcination atmosphere—air, nitrogen, or hydrogen—during catalyst preparation. By employing a urea-assisted hydrothermal method followed by controlled calcination, the authors demonstrate that air calcination yields a catalyst with superior metal-support interaction, enhanced copper dispersion, and a higher proportion of Cu+ species. These microstructural improvements translate into exceptional catalytic performance, achieving 92.37% DMS conversion and 64.15% BDO yield under industrially relevant conditions. This work provides a pragmatic, scalable strategy to overcome the longstanding challenge of optimizing Cu/SiO2 catalysts for efficient hydrogenation.
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SHAO Xuhao, ZHANG Xuyan, CHEN Xiaorong, DU Jiaxin, AI Peipei, TAN Minghui, GAO Zhihua, HUANG Wei (2026). Calcination Atmosphere-Engineered Cu/SiO2 Catalysts for Efficient Hydrogenation of Dimethyl Succinate to 1,4-Butanediol. Journal of Fuel Chemistry and Technology. https://doi.org/10.1016/S1872-5813(26)60663-9
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Frequently Asked Questions
What is the optimal calcination atmosphere for Cu/SiO2 catalysts in DMS hydrogenation, and what performance metrics were achieved?
Air calcination (Cu/SiO2-A) yielded the best performance, achieving 92.37% DMS conversion and 64.15% BDO yield under 210 °C, 5.0 MPa, WHSV 0.6 h−1, and H2/DMS molar ratio 100.
How does calcination atmosphere affect copper dispersion and the proportion of Cu+ species?
Air calcination promotes stronger metal-support interactions, leading to higher copper dispersion and a larger fraction of stabilized Cu+ species compared to inert or reducing atmospheres, as evidenced by N2O chemisorption and XPS.
What is the role of surface acidity in the hydrogenation mechanism?
Surface acid sites, identified via NH3-TPD, facilitate C=O polarization, enhancing the adsorption and activation of the ester carbonyl group, which synergizes with Cu+ sites for selective hydrogenation to BDO.
Are the optimized conditions industrially viable?
Yes, the conditions (210 °C, 5.0 MPa, WHSV 0.6 h−1) are typical for industrial fixed-bed hydrogenation, and the achieved conversion and yield are competitive, suggesting potential for scale-up.
What are the key structural differences between air-calcined and other catalysts that explain performance?
Cu/SiO2-A exhibits the strongest metal-support interaction, highest copper dispersion, and largest Cu+ population, which collectively enhance hydrogen activation and carbonyl adsorption, leading to superior activity and selectivity.
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