铁基ABO3型氧化物微结构可控构建及其调控丙烷直接脱氢机制研究

丙烷直接脱氢是填补全球丙烯缺口的重要合成路线，与传统Pt基和Cr基催化剂相比，具有成本优势、绿色环保的Fe基氧化物催化剂具有重要开发前景。本项目致力于认识和解决Fe基氧化物在高温还原条件下活性中心配位环境和晶格氧活性不可控导致的催化剂活性低、稳定性差的瓶颈问题，其属于氧化物脱氢催化剂开发中的共性难点。基于ABO3型氧化物晶格氧活性灵活可调的特点，以LaFeO3为起点，利用A/B位部分替代离子种类、价态和半径差异等因素调控其晶格氧活性，并结合还原条件因素可控调变Fe-O活性中心配位环境和晶格氧活性等微结构特征；耦合原位表征、理论计算等手段，揭示活性位微结构随调控因素的演变规律和调控机制；结合丙烷脱氢反应性能、动力学分析和反应机理研究，明确Fe基氧化物微结构对丙烷脱氢反应历程的调变规律，阐明结构效应本质。本研究将为氧化物脱氢催化剂理性设计及丙烷脱氢高效催化剂开发提供理论和应用基础。

Propane direct dehydrogenation is an important synthetic route to fill the global propylene gap. Compared with traditional Pt and Cr based catalysts, Fe based oxide catalysts are promising candidates because of their cost and environmental advantages. This project is dedicated to understanding and solving the bottleneck problem of low activity and poor stability of Fe-based catalysts caused by the uncontrollable coordination environment of active site and lattice oxygen in Fe-O bond under high temperature reduction conditions, which belongs to the common difficulties in the development of metal oxides catalyst for dehydrogenation. As ABO3 type oxides are flexible in lattice oxygen activity manipulation, the LaFeO3 will be used as the starting material for controllable micro-structure manipulation of Fe-based oxides by adopting mainly A/B site partial substitution strategy. The coordination environment and lattice oxygen activity of Fe-O active site will be manipulated by combing factors of ion type, valence states, radius differences of the substitution ions and reduction conditions. In addition, the evolution law and formation mechanism of active site micro-structure will be established by coupling of In-situ characterization techniques and theoretical calculations. By analyzing the performances of propane dehydrogenation, kinetics and reaction mechanism based on theoretical calculation, the effects of active site micro-structure on the propane dehydrogenation reaction routines and the intrinsic nature of structure effect will be elucidated. This project lays solid theoretical and application foundation for the design of metal oxides catalysts for propane dehydrogenation.