MCM-22分子筛的酸性调控及其甲醇制丙烯催化性能研究

甲醇制丙烯技术是一条替代石油资源制备丙烯的重要途径，具有重要的应用价值。研发高丙烯选择性、高丙烯乙烯比和高稳定性的酸性微孔分子筛催化剂是该技术的核心问题，针对适宜的催化剂进行孔道和酸性调控、揭示反应机理是研究甲醇高效制丙烯的重要课题。本项目以MCM-22分子筛催化甲醇制丙烯为研究目标，通过在合成过程中添加不同的杂原子和适宜的后处理改性来选择性的调控不同孔道中的酸量、酸强度和酸位分布，结合同位素标记跟踪的脉冲反应、共进模拟“烃池”物种、原位红外光谱、紫外漫反射光谱、核磁共振和GC-MS等实验方法和表征技术，深入研究不同酸性调控方法对MCM-22分子筛不同孔道中酸性的影响，认识酸性中心的本质对“烃池”物种结构、组成和演变过程及产物分布和催化剂失活再生性能的影响。

Conversion of methanol to propene over acid zeolite is considered as a promising alternative route for the production of propene from petroleum. According to the well accepted hydrocarbon pool mechanism, the zeolite structure and pore size and catalyst acidity determine the product distribution. The key issue is to develop highly selective and stable catalyst. Thus, it is a challenge to improve the catalytic performance and further understanding the catalytic mechanism in the unique zeolite pore/channel with different acidity. In this project, attempts will be made to investigate the effect of incorporation of B, Fe or Ti atoms and several post treatments of MCM-22 on regulation the catalyst acidity. Pyridine adsorbed IR, 1H MAS NMR, trimethylphosphine adsorbed 31P MAS NMR and 27Al MQ MAS NMR spectra will be used to analysis the structure and acidity change. Combination with the isotopic experiments and co-feeding experiments, the formation mechanism of first C-C bond, composition and changes of the active “hydrocarbon pool” species and products distributions will be studied by using the GC-MS, in-situ FT-IR, UV-Vis, 1H and 13C MAS NMR techniques. Further give insight into the effect of acidity of MCM-22 on the catalytic performance and deactivation-regeneration behavior.