糠醛制γ-丁内酯可持续工艺路线的催化过程研究

In recent years, the production of fuels and chemicals from biomass has received much attention. Furfural, a renewable C5 platform compound from lignocellulose, is a promising alternative feedstock for producing fine chemicals because of its highly functional structure. In this project, we propose a novel two-step strategy for converting furfural to γ-butyrolactone (GBL), a high value-added fine chemical, consisting of furfural oxidation to 2(5H)-furanone and selective hydrogenation of 2(5H)-furanone to GBL. Based on our previous study, the proposed research will be carried out as follows: (1) Study the solvent effect for furfural oxidation reaction, establish simplified reaction networks to quantitatively correlate the solvent properties with the product distribution, and finally identify the suitable solvents; (2) Study the reaction mechanism of 2(5H)-furanone hydrogenation by surface science experiments and DFT calculations, investigate the relationship between the catalyst structure and catalytic performances, and design highly efficient supported bimetallic catalysts for selective hydrogenation of 2(5H)-furanone; (3) Use formic acid, a byproduct from furfural oxidation, as the hydrogen donor for the selective hydrogenation of 2(5H)-furanone, design metal catalysts for this catalytic transfer hydrogenation reaction and further improve the atom economy of the proposed new reaction route for producing GBL from furfural. The proposed research would make important contributions to develop new processes and highly efficient catalysts for producing high value-added chemicals from biomass platform compound.

近年来，生物质转化制燃料和化学品引起了研究者的重视。糠醛是一种绿色、可再生的C5生物质平台化合物，其高度官能化的分子结构使其成为化学品合成的理想原料。本课题提出以糠醛为原料、2(5H)-呋喃酮为中间体、经催化氧化和催化加氢两步合成高附加值精细化学品γ-丁内酯（GBL）的新工艺。拟在前期研究工作基础上，深入研究糠醛催化氧化制2(5H)-呋喃酮的溶剂效应，建立动力学网络以定量表征溶剂对产物分布的影响规律，指导溶剂筛选；借助表面实验和DFT计算等基础研究手段，揭示2(5H)-呋喃酮选择加氢反应机理以及催化剂结构-催化性能关系，设计高效双金属负载型催化剂；将糠醛氧化制2(5H)-呋喃酮副产的甲酸作为2(5H)-呋喃酮选择加氢的氢源，实现反应耦合并进一步提高糠醛制GBL新工艺的原子经济性。该项目将开发由生物质平台化合物制高附加值化学品的新工艺及高效催化剂，具有重要的学术和应用价值。

提出了以糠醛为原料、2(5H)-呋喃酮为中间体，经过催化氧化和催化加氢两步合成高附加值化学产品γ-丁内酯的新工艺路线。该工艺路线流程简洁，兼顾了反应物和目的产物的分子结构特点，具有很高的原子经济性。针对糠醛选择性氧化制2(5H)-呋喃酮反应，研究了不同酸催化剂的性能及其作用机理，发现甲酸在双相反应体系中具有最好的催化性能。在优化的反应条件下，以过氧化氢为氧化剂、1,2-二氯乙烷或乙酸乙酯为溶剂形成双相反应体系，甲酸为催化剂，可获得60~63%的2(5H)-呋喃酮收率并联产20~30%的高附加值二元酸（琥珀酸和马来酸）。针对2(5H)-呋喃酮选择加氢制γ-丁内酯反应，制备和表征负载型单金属催化剂M/SiO2（M = Pt、Pd、Rh、Ru、Ni、Co、Cu）并进行液相加氢反应评价。成功开发了镍基非贵金属催化剂Ni-M/SiO2（M = Fe、Co、Cu、Zn），其中Ni4.0-Fe1.0/SiO2加氢活性接近贵金属催化剂Pd0.5/SiO2，比Ni5.0/SiO2催化剂活性提高约1倍，γ-丁内酯收率约为90%。结合催化材料表征结果与超真空表面实验，进一步揭示了Ni-Fe双金属催化剂的结构与性能构效关系。