金属基离子液体导向合成VPO催化剂及催化正丁烷氧化基础研究

N-butane selective oxidation to maleic anhydride based on vanadium phosphorus oxide (VPO) catalyst is one of significant application for the high-value utilization of lower hydrocarbon. To solve the problems of VPO catalyst prepared by traditional organic-phase method due to their poor conversion and selectivity, a new synthesis method by ionic liquids (ILs) strengthened was proposed in this work to prepare the VPO catalyst from the point of the view of structure and crystalline phases. Using the combination of quantum computation and experiment, a series of metal-based functionalized imidazole ILs were designed and synthesized. Afterwards, under the synergistic effect between the structure-directing of cationic and metal dopant of anionic, VPO catalysts with high specific surface area, highly active phase and homogeneous structure were controllably prepared, which realize highly selective oxidation of n-butane. The influence of ILs structure, functional groups and interaction on the catalyst influence rule and synergistic effect will be systematically investigated, the crystallization and regulation mechanism of catalyst microstructure were obtained. In addition, the diffusion, adsorption and selective oxidation of n-butane in VPO were also studied, and the structure-activity relationship between nanostructure, crystal phase and catalytic performance of the n-butane was further revealed. This project will provide theoretical and technical basis for the design of maleic anhydride catalyst with high selectivity and their industrial application.

钒磷氧（VPO）催化氧化正丁烷制顺酐是低碳烃高值化利用的重要途径。针对目前有机相法制备的VPO存在正丁烷转化率低、顺酐选择性差等难题，本项目基于离子液体良好的配位性能和结构可调等优势，提出金属基离子液体导向制备VPO催化剂的新思路。采用量子计算和实验相结合，设计合成新型金属基咪唑类离子液体，在离子液体高电荷密度阳离子的结构导向和金属阴离子电子助剂的协同作用下，从结构和晶相双层调控角度，可控合成具有高比表面积、高活性相、结构均一的VPO催化剂，从根本上突破正丁烷高活性和高选择性氧化瓶颈。重点研究离子液体阴阳离子结构、功能基团及相互作用等对VPO合成的影响规律和协同效应，获得催化剂微观结构的晶化机理和调控机制。探究正丁烷在VPO中的扩散、吸附及选择性氧化反应规律，揭示VPO的微观结构、晶相与正丁烷催化转化性能间的构效关系。本项目将为高效顺酐催化剂的开发及相关技术的应用提供理论基础与科学依据。

钒磷氧（VPO）催化氧化正丁烷制顺酐是低碳烃高值化利用的重要途径。针对目前有机相法制备的VPO存在正丁烷转化率低（~80%）、顺酐选择性差（~60%）等难题，本项目基于离子液体良好的配位性能和结构可调等优势，提出金属基离子液体导向制备VPO催化剂的新思路。采用COSMO量子计算和实验相结合，设计合成系列新型金属基咪唑类离子液体BMIMFeCl4，BMIMCoCl4，BMIMAlCl4，BMIMCuCl3等，在离子液体高电荷密度阳离子的结构导向和金属阴离子电子助剂的协同作用下，从结构和晶相双层调控角度，可控合成具有高比表面积、 高活性相、结构均一的VPO催化剂，从根本上突破正丁烷高活性和高选择性氧化瓶颈，最高实现正丁烷的转化率92.1%和顺酐选择性70.2%，顺酐收率为64.9%，顺酐收率相对于空白VPO催化剂提高了26.4%。重点研究离子液体阴阳离子结构、功能基团及相互作用等对VPO合成的影响规律和协同效应，离子液体丰富的氢键作为氢供体和底物分子间的表面电荷具有很强的互补性，极易发生作用，并且氢键起着主要作用，从而诱导了催化剂的结构和形貌的改变。多价态的金属电子层外较多的空轨道与和物分子V进行配位，起到电子传输的作用，进而起到电子助剂的作用。从而获得催化剂微观结构的晶化机理和调控机制。探究正丁烷在VPO中的扩散、吸附及选择性氧化反应规律，揭示VPO的微观结构、晶相与正丁烷催化转化性能间的构效关系。目前发表SCI论文7篇，中文期刊1篇，授权专利7项。本项目将为高效顺酐催化剂的开发及相关技术的应用提供理论基础与科学依据。