木质素及其裂解产物中芳香甲氧基基团的高效定向转化研究

Lignin is renewable carbon resource which is abundant of aromatic structure, and its transformation to valuable compound is a very important subject. However, it is a great challenge for the selective transformation of lignin because the complexity of the structure. There are a large number of aromatic methyl ether groups in lignin and its pyrolytic products. High selectivity conversion and utilization of these groups is one of the important ways for the utilization of lignin. This project will study the carbonylation and hydrolysis of the aromatic methyl ethers to produce phenolic compounds and acetic acid, and the carbonylation and hydrolysis of lignin to produce lignin which is rich in phenolic hydroxyl groups and acetic acid. Nanometallic catalysts supported on acid support will be designed and prepared. Their catalytic properties for these reactions were studied in different reaction media. The synergetic mechanism between acid support and metal nanoparticles, the synergism between different metals, and the synergy between catalyst and reaction medium were investigated. The rules and mechanism of ether bond activation and the formation of various chemical bonds during the reaction were revealed. Various efficient catalytic systems were obtained, and the reaction conditions were optimized. This project provides a new method and approach for the transformation of aromatic methyl ether compounds and lignin. This project is about synthetic chemistry, catalytic chemistry and biomass conversion and utilization.

木质素是十分丰富的可再生芳香碳资源，其资源化利用是国内外普遍关注的重大课题。由于木质素结构复杂，实现其高效定向转化是一个挑战性难题。木质素及其裂解产物中存在大量的芳香甲氧基基团，高选择性转化利用这些基团是木质素高值化利用的重要途径之一。本项目针对芳香甲基醚类化合物与CO、水反应生成乙酸和酚类化合物，以及木质素与CO、水反应生成乙酸和富含酚羟基的木质素，设计制备纳米金属（包括多金属）/酸性载体多功能非均相催化剂，在不同反应介质中研究它们对这些反应的催化性能。探明酸性载体与金属纳米颗粒之间的协同作用机理、不同金属之间的协同作用、催化剂与反应介质之间的协同作用，揭示反应过程中醚键活化以及各种化学键的形成规律和机理。获得多种高效催化体系，优化的反应条件，为芳香甲基醚类化合物和木质素的高值化利用提供新的方法和途径。本项目是合成化学、催化化学、生物质转化利用等相互交叉渗透的前沿课题。

木质素中含有大量的芳香甲基醚结构，芳香甲基醚类化合物是木质素裂解中的一类重要产物并广泛存在于各种植物中。木质素中芳香甲氧基基团的利用以及芳香甲基醚类化合物的高效定向转化是木质素转化化学的重要研究内容之一。本项目按照预期计划，开展芳香甲基醚类化合物经羰基化、水解反应制备酚类化合物和乙酸的新型反应路线，发展了木质素与CO2和 H2反应制备乙酸反应制备乙酸和酚类化合物的新路线以及木质素中内部侧链和芳环综合利用新策略。阐明了相关催化反应机理，揭示催化剂结构与性能的关系。揭示催化剂性质、溶剂性质、底物性质、温度、压力等因素对反应转化率和选择性的影响规律和机理，为实现木质素的高值化利用奠定科学基础。发表文章20篇，申请专利2项，完成了研究目标。