生物质基1,3-丙二醇高效制备中纳米复合催化剂的界面增强效应及氢解机理

本项目为解决常规负载型催化剂上生物质多元醇选择性氢解为高附加值1,3-丙二醇中存在的活性和选择性低下问题，构建具有金属-酸（碱）界面结构的功能集成纳米复合催化剂体系应用于生物质基山梨醇/木糖醇选择性氢解为丙三醇（金属-碱）和丙三醇选择性氢解为高附加值的1,3-丙二醇（金属-酸）的两步转化路径。(1)通过溶液化学法设计合成尺寸和形貌（高活性晶面集中暴露）可控的金属-酸（碱）催化剂以调节其界面结构与性质。(2)借助催化剂界面电子转移引导的增强效应，阐明山梨醇氢解为丙三醇的选择性脱氢（金属中心）与C-C键断裂（碱中心），以及丙三醇伯羟基配位吸附（酸中心）和氢溢流条件下增强的仲羟基活化裂解（金属中心）的协同反应机理和关键中间产物生成与转化路径。通过项目研究，为生物质基1,3-丙二醇化学品的高效制备提供理论基础与技术支撑。

Considering the conventional supported catalysts showed low activities and selectivities in hydrogenolysis of biomass-derived polyols (sorbitol,xylitol and glycerol) to the value-added 1,3-propanediol,this project aims to fabricate functional assembly nano-composite catalysts with interfaces for two-step hydrogenolysis of sorbitol/xylitol to glycerol (metal-alkali), which is followed by hydrogenolysis to 1,3-propanediol(metal-acid) in terms of activity and selectivity.By using chemical synthesis in solution,this project will prepare the bifunctional nano-composite catalysts with metal-base and metal-acid interfaces with well-defined sizes and geometries due to that the interface sturcture and property could be tailored by the size and shape of metal and acid/base kinds.With the aid of enhanced effects by electron transfer at the metal-base and metal-acid interfaces,this project will investigate the synergistic dehydrogenation of C2 atom in sorbitol and/or C1 or C2 atom in xylitol and selective scission of C3-C4 bond in sorbitol and/or C2-C3 bond in xylitol at metal-base interface, and the cooperative activation of primary hydroxyl of glycerol to alkoxide species and cracking of its second hydroxyl by attack of over spilled hydrogen at metal-acid interface.Furthermore,this project will also study the synergistic hydrogenolysis mechanism during the biomass-derived polyols transformation,and elucidate the activation behavoirs of reactants and the transferring approaches of key intermediates over the functional assembly nano-cataysts.By these investigation,this project will provide scientific fundament and technical support for selective hydrogenolysis of biomass-derived polyols to value-added chemicals.