非均相铁催化生物质基5-羟甲基糠醛选择性加氢脱氧制2,5-二甲基呋喃的研究

The chemical conversion of cellulosic biomass is of great significance to the energy and chemical industry, and the development of low-cost, highly selective iron-based catalytic system will make biomass conversion greener and more economic. In this project, a series of heterogeneous iron catalysts will be constructed aimed at selective hydrodeoxygenation of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran, and the doping of nonmetallic elements is essential to the enhanced hydrodeoxygenation activity. Through the investigation of preparation parameters such as the type of dopant element, precursor, support, and pyrolysis temperature, and reaction factors such as temperature, hydrogen pressure, and solvent, the control of electronic structure, Lewis acidity/basicity and hydrodeoxygenation activity/selectivity of iron catalysts will be achieved. Subsequently, the structure changes in iron catalysts upon doping of nonmetallic elements will be explored by using various characterization methods, and the mechanism of doping to enhance the hydrodeoxygenation activity of iron will be revealed. Finally, the coupling of acidic hydrolysis and iron-catalyzed hydrodeoxygenation will be studied to eliminate the 5-hydroxymethylfurfural purification step during the production of 2,5-dimethylfuran from hexoses. The heterogeneous iron catalysts developed in this project will also hold great potential to provide a series of new reaction pathways and methods for other biomass conversions due to its excellent hydrodeoxygenation activity.

纤维素类生物质选择转化对能源和化学工业的可持续发展具有重要意义，发展低成本、高选择性的铁催化体系可以使生物质转化过程更加绿色经济。本项目将构建一系列非均相铁催化剂以实现生物质基5-羟甲基糠醛选择性加氢脱氧制2,5-二甲基呋喃，非金属元素的掺杂对铁催化剂加氢脱氧活性的提高至关重要。通过研究掺杂元素类型、前体、催化剂载体和热解温度等制备参数及温度、氢压和溶剂等反应参数，调控铁催化剂的电子结构、lewis酸碱性和加氢脱氧活性及选择性；随后利用多种表征手段探究非金属元素掺杂前后催化剂结构变化规律，揭示掺杂对铁加氢脱氧活性增强的作用机制；最终通过酸水解与铁催化加氢脱氧反应的耦合消除六碳糖制2,5-二甲基呋喃过程中5-羟甲基糠醛的分离提纯步骤。本项目发展的非均相铁催化剂所具有的优良加氢脱氧活性还将非常有潜力为其它生物质转化反应提供一系列新反应路径及新方法。

Fe作为地壳中含量最丰富的过渡元素，价格低廉，可能是最有吸引力的用于生物质转化的非贵金属元素。本项目发展了一系列经济、环保的Fe-N-C催化剂。通过对铁负载量、载体酸性、掺杂（非）金属元素类型等关键制备因素的系统研究，成功的将铁催化5-羟甲基糠醛加氢脱氧到2，5-二甲基呋喃的选择性提高到95%左右，并发现FeN3位点极有可能是铁催化剂的关键活性位点。此外，该铁催化体系还拓展至多种生物质重要的化学反应，为生物质转化提供一系列新催化体系、新反应路径和新方法。完成了既定的研究目标，同时为后续研究奠定了基础。相关工作在ACS catalysis、Applied Catalysis A, General、有机化学等期刊上发表论文多篇，均标注致谢了本项目资助。