新型纳米碳化物及其催化甲醇脱氢行为研究

近年来甲醇行业快速扩张，高效绿色的甲醇下游技术日益受到重视。由甲醇脱氢合成重要的平台化合物甲酸甲酯(MF)是其中的代表，高效催化剂是目前技术发展瓶颈所在。本项目从甲醇脱氢反应机理出发，提出新颖的纳米碳化物合成路线- - 突破"原位"碳化中氮卤配位概念，利用有机硅前体自身配位与导向功能，在纳米尺度构建高分散有机-无机杂化前驱体，并以其自身烷基团为碳源实现碳化。这一技术路线可有效促进母体金属向碳化物相的转变，形成表面洁净、物相结构均布的纳米复合碳化物。由于所得碳化物电子轨道进一步收缩，d带态密度增高，表面合金效应得到增强，极大强化甲醇吸附活化与催化转化能力，有望成为一类高效甲醇脱氢催化剂。本项目以甲醇下游技术为背景，选取模型反应和催化体系均具有典型性，所涉及的配位组装、表面化学及反应机理等科学认识对于新型碳化物材料及甲醇活化转化具有较高学术价值，同时对于绿色高效甲醇下游技术的发展具有积极意义。

Recently, green efficient methanol downstream technologies have been increasingly got recognition with methanol industry rapid expansion. Production of methyl formate (MF) , green building block chemical, by methanol dehydrogenation is one of the representatives. The catalyst performance is the technical bottleneck. Rooting in the reaction mechanism and the behavioral characteristics of various types of catalysts, the project is proposed to prepare novel nano-carbides-silica catalysts controllably. By making the siloxane function as metal coordinating and structure-directing agent, we obtain high-dispersed organic-inorganic hybrid precursor at nano-scale, then achieve controllable carbonation with their own alkyl group as carbon source to promote the parent metal transformation into carbide phase efficiently to form clean and highly dispersed nano-composite carbides, thus, expand the conception of coordination, which is essential for in-situ carbonization. In that case, the obtained carbides electronic orbits contract further. In response, d band state density increase. Eventually, the surface alloying effect is enhanced and the carbides present great methanol dehydrogenation performance. The project selects a typical reaction process and catalyst system in the background of methanol downstream. The studies involving self-assembly, surface chemistry and reaction mechanism et al are academically valuable for the understanding of carbides catalysis and methanol activation. And the novel catalysts will be also meaningful for the grow of methanol downstream technologies.