半纤维素原料定向转化合成二元醇高效催化剂构筑和反应调控机制的研究

半纤维素定向转化合成乙二醇和丙二醇大宗生物化学品，对于缓解当今日益严峻的能源和资源短缺问题具有重要的科学意义。本项目采用温和水解、催化氢解二步策略，实现林业剩余物半纤维素定向转化及产物选择调控。采用优化的制备方法，构筑尺寸和结构可控的纳米空心球“限域”的Ni基双金属催化剂，研究它们催化半纤维素水解液氢解制备二元醇的反应性能。应用X-射线光电子能谱、化学吸附、高分辨透射电镜等分析手段，研究催化剂活性组分结构，从原子/分子水平上阐明催化剂表-界面结构与氢解性能的关系。应用原位拉曼光谱技术，动态跟踪氢解反应过程关键中间产物产生及转化规律，揭示氢解反应机理。初步建立调控催化反应路径的有效方法，设计优化催化剂表-界面结构和活性中心，有望达到在温和条件下催化半纤维素原料定向转化为二元醇等目标产物，这些方面的研究将为催化剂分子设计和林业剩余物半纤维素的高值化利用提供理论基础和科学依据。

The catalytic synthesis of ethylene glycol and propylene glycol using hemicellulose as a starting material is of great scientific significance for alleviating the increasingly serious energy and resource shortage. In this project, the two-step strategy of mild hydrolysis and catalytic hydrogenolysis will be employed to realize the catalytic transformation of hemicellulose and product selectivity regulation. A novel Ni based bimetallic catalyst with controllable size and structure will be fabricated by optimizing preparation steps, and their catalytic performance for the synthesis of diols from hemicellulose hydrolysate will be investigated. X-ray photoelectron spectroscopy (XPS), chemisorption and high resolution transmission electron microscopy (HRTEM) will be employed to study the structure of the active sites of the catalyst and reveal the relationship between the structure of surface-interface and catalytic performances at the atomic/molecular level. In situ Raman spectroscopy will be used to dynamically track the formation and conversion of key intermediates in the hydrogenolysis process and reveal the mechanism of hydrogenolysis. An effective method for regulating the catalytic reaction path will be preliminarily established. It is expected to achieve the goal of efficient conversion of hemicellulose raw materials to diols under mild conditions, and these studies will provide theoretical understanding and scientific insights for the molecular design of catalysts and the high-value valorization of forestry residue hemicellulose.