甲醇转化催化剂限阈空间内环状有机物种的生成、催化机制及复合体系的主客体化学作用

Methanol-To-Olefins process has gained the success in its industrilization. Further developments in new catalysts and catalytic processes call for the deep understanding of the reaction mechanism and the complete reaction prospect of this heterogeneous process. The formation and function of the confined cyclic organic species in the catalyst with cage structure is of great significance in heterogeneous catalysis of methanol conversion. In the present work, by employing the in-situ reaction techniques in combination with the structure identification of the confined organics, the reaction routes will be determined corresponding to the retained materials evolution in the catalyst phase. At the same time, the interaction between the confined organics and the cage structure, which behaves as the chemical environment for the confined organics formation, will be studied to establish the reaction mechanism involving intermediate-selectivity and catalyst deactivation. Furthermore, confinement effect and interaction occurring in inorganic-organic composites will be investigated and discussed. In an extended study,based on our new discovery of adamantane hydrocarbons formation and accommodation as the retained materials in the cage of CHA molecular sieves during methanol conversion, inorganic-organic composites, CHA cage-adamantane derivatives composites, will be proposed and explored. Their host-guest interaction, such as the structure recognition and structure directing, which have appeared in two distinct and correlated fields, the hydrothermal synthesis of molecular sieves and the catalysis of molecular sieves, will be investigated.

甲醇制烯烃已经成功实现工业化。催化剂和过程开发的进一步发展要求研究者对甲醇转化机理和多相催化的碳资源走向有更为深刻的理解。分子筛空间限阈条件下环状有机物种的生成和催化作用是多相催化甲醇转化反应机理研究的核心内容。本项申请中，将通过原位反应技术结合对分子筛限阈条件生成的有机物种的结构识别，研究反应催化剂相有机物种的生成和演变，由此建立由催化剂相的有机物种引导的甲醇转化的多相催化反应机制。同时从分子筛笼结构化学环境与限阈形成的有机物种这一复合体系的相互作用出发，建立分子筛催化的过渡态反应机理和失活模型。进一步拓展分子筛和限阈空间中有机物种这一无机-有机复合体系的研究，以最新发现的甲醇转化过程中金刚烷化合物在CHA结构分子筛中的形成和沉积为基础，以CHA分子筛笼-金刚烷衍生物的复合体系作为研究对象，联系分子筛合成和分子筛催化两个领域，探索其相互结构识别和相互引导生成的主客体化学作用。

甲醇制烯烃（Methanol-to-Olefin, MTO）过程是联系煤化工和石油化工的桥梁。催化剂和过程开发的进一步发展都要求研究者对甲醇转化机理和多相催化的碳资源走向有更为深刻的理解。分子筛空间限阈条件下环状有机物种的生成和催化作用是多相催化甲醇转化反应机理研究的核心内容。通过四年的工作努力，采用多种实验技术，逐步解决了多相催化甲醇转化反应过程中SAPO分子筛催化剂笼结构限阈空间内环状有机物种的形成和结构确认。深入系统研究了催化剂与限阈生成的环状有机物种构成的无机-有机复合催化体系，对这一体系的作用原理有了更为理性和深入的认识，提出了笼结构控制的反应调控原理。讨论了笼结构分子筛催化环境与限阈空间形成的环状有机物种相互作用的化学基础，提出酸性和结构影响反应活性中间体的生成进而影响MTO反应中烯烃生成途径。在这些工作基础上，拓展无机-有机复合体系研究，研究MTO反应中多种分子筛和有机物种的复合体系，并通过理论模拟建立了包括CHA结构、LEV结构、TON结构以及BEA结构的多种分子筛催化甲醇转化的催化反应循环。