失活钛硅分子筛催化烯烃裂解选择性生成C2=/C3=的研究

烯烃裂解是将低值C4=/C5=等副产资源催化转化成高值C2=/C3=的过程，提高C2=/C3=选择性和C原子利用率是其技术发展的动力和目标，核心科学问题是氢转移反应的调控。基于前期研究基础，项目从碳正离子反应机理入手，构建C2=/C3=选择性和C原子利用率最大化导向的反应网络，揭示需关键调控的氢转移反应，定义针对性更强的氢转移指数；基于分子筛择形和酸中心调控反应路径基本原理，提出采用失活TS-1废催化剂为基础研发高效烯烃裂解催化剂的新思路、发展构筑与骨架Ti相邻硅羟基B酸中心的新方法，阐明失活TS-1中酸中心结构、酸强度和酸密度对C4=/C5=裂解反应的影响，尤其是与C2=/C3=选择性之间的关系，进而实现关键氢转移反应的有效调控。项目将实现C4=/C5=副产高值化和废催化剂固废资源化两者的有机结合，也将固体酸催化从传统硅铝分子筛酸功能研究发展至钛硅分子筛酸功能这一新方向的研究。

Olefin cracking is the process of catalytical converting low-value C4=/C5= into high-value C2=/C3=. Improving the selectivity of C2=/C3= and C-atom utilization efficiency is the driving force and goal of this technology. The heart of the scientific problem is the regulation of hydrogen transfer reactions. Based on our previous studies, the project starts with the carbenium ion reaction mechanism, constructs a reaction network oriented to maximize C2=/C3= selectivity and C-atom utilization efficiency, reveals the hydrogen transfer reactions requiring crucial control, and defines a more targeted hydrogen transfer index. In view of the shape-selectivity of zeolites and the basic principles of acid sites controlling reaction pathways, the project proposes a new idea for the development of a high-efficiency olefin cracking catalyst based on the deactivated TS-1 catalyst, presents a new approach for constructing Brønsted acid sites of Si–OH groups adjacent to the framework Ti in zeolite. And also it clarifies the effect of the structure of acid sites, acid strength and acid density in deactivated TS-1 on C4=/C5= cracking reactions, especially the relationship with C2=/C3= selectivity, then realizing the effective control of the key hydrogen transfer reactions. The project will realize the organic combination of high-valued utilization of by-products C4=/C5= and the recycling of solid waste catalysts, and develop a new direction of solid acid catalysis from the study on the acid function of traditional aluminosilicate zeolites to that of titanosilicate zeolites.