生物质基5-羟甲基糠醛直接脱氢反应催化体系构建和机理研究

Biomass conversion is of great significance to the sustainable development of energy and chemical industry. A process for biomass conversion with high safety, mild reaction conditions, high atom utilization and high selectivity will be greener and more economy. In this project, a series of Mo-based carbides will be developed for direct dehydrogenation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF), which can effectively enhance the selectivity of DFF and simplify the separation and purification process. Firstly, a series of Mo-based carbides with specific sizes, crystal type, morphology and high catalytic dehydrogenation activity will be developed by adjusting the structure of precursor, calcination temperature and other synthesis parameters. The relationship between the structure of Mo-based carbides and dehydrogenation activity will be also explored. Then, other metals or nonmetals will be studied as additives to modify the electronic structure, geometrical configuration and dehydrogenation activity of Mo-based carbides. The effect of additives on the structure, physico-chemical properties and dehydrogenation activity of Mo-based carbides will be also studied. Finally, the compatibility of dehydration of biomass-based carbohydrates and dehydrogenation of HMF will be studied, aiming at production of DFF from biomass-based carbohydrates via dehydration and dehydrogenation in a one-pot style. The Mo-based carbides and the reaction pathway of HMF dehydrogenation developed in this project will provide experimental and theoretical basis for other biomass conversions.

生物质转化对能源和化学工业的可持续发展具有重要意义，发展安全、条件温和、高原子利用率和选择性的转化路径可以使生物质转化过程更加绿色经济。本项目将构建Mo基碳化物催化体系以实现生物质基5-羟甲基糠醛（HMF）直接脱氢制2,5-呋喃二甲醛(DFF)，有效解决当前DFF制备过程中副产物多、分离纯化难等问题。具体包括：（1）通过研究前体结构、煅烧温度等制备参数构筑一系列具有高脱氢活性的特定尺寸、晶型和形貌的Mo基碳化物，探索其结构与脱氢性能间的关系；（2）通过助剂改性调控Mo基碳化物的电子结构、几何构型及脱氢活性，探究助剂改性前后Mo基碳化物结构和性质的变化规律，揭示助剂对脱氢性能增强的作用机制；（3）通过生物质脱水反应和HMF脱氢反应兼容性研究，实现生物质基碳水化合物经脱水和脱氢一锅制备DFF。本项目构建的Mo基碳化物催化体系和发展的HMF直接脱氢反应路径可为其它生物质转化反应提供新的科学依据。

随着化石资源的日益枯竭和生态环境问题的日益严峻，开发利用清洁可再生的生物质资源至关重要。在本研究项目中，拟实现生物质基碳水化合物到高附加值化学品的转化。（1）采用简单的混合、干燥和煅烧的方法制备了β-Mo2C@C催化剂，采用水热法制备了α-MoO3催化剂，（2）采用SEM、TEM、EDS、XRD、XPS和NH3-TPD等多种表征方法分析了所制备的β-Mo2C@C和α-MoO3催化剂的形貌、组成和结构。（3）系统研究了多种反应参数如反应时间，温度，溶剂，氧气流速等对β-Mo2C@C （α-MoO3）催化HMF氧化制备DFF的影响。（4）结合实验结果和催化剂表征结果探讨了催化剂的构效关系和反应机理。（5）通过生物质脱水反应和HMF脱氢反应兼容性研究，实现生物质基碳水化合物经脱水和脱氢 一锅制备DFF。