基于MTP催化剂的多相催化过程扩散-表面反应耦合特性研究

甲醇制丙烯是促进我国煤炭资源高效清洁利用和缓解石油对外依赖度的有效途径。甲醇制丙烯固定床工艺的催化剂主要为ZSM-5分子筛。针对甲醇制丙烯催化剂稳定性差和丙烯选择性较低的问题，着眼最根本的扩散和表面反应规律，协同调变催化剂孔道结构和酸性。通过碱处理、合成片状分子筛等手段调节孔结构；通过改变合成体系、改变助剂等方式调节Al状态以控制酸性，最终得到高性能催化剂。在此基础上，结合密度泛函理论和微动力学模型，研究甲醇制丙烯反应机理，阐明孔结构和酸性共同作用的扩散-表面反应耦合特性，产物分布调变的共性机制，及Al状态的调变机制，及其对表面反应和碱处理的作用规律等科学问题。掌握扩散-表面反应耦合和产物分布调变的强化方法。解决催化剂稳定性差和丙烯选择性低背后的科学问题，指导高性能催化剂设计合成，有助于推动甲醇催化转化利用的技术多样化和煤炭资源高效清洁利用，具有科学意义和应用前景。

Methanol conversion to propylene (MTP) is an efficient approach to promote the efficient and clean utilization of coal resources and to alleviate the high dependence on imported crude oil. ZSM-5 is the most popular catalyst for fixed-bed MTP process. In view of the poor stability and relatively low selectivity to propylene of MTP reaction over ZSM-5 catalyst, focusing on the fundamental laws of diffusion and surface reaction, we will investigate the effects of pore structure and acidity properties, and their coordinating modification. The pore structure will be adjusted by means of alkali treatment, synthesis of sheet molecular sieves, etc., and the Al state will be adjusted to control the acidity by changing the synthesis system, and finally a high performance catalyst will be obtained. On this basis, combining density functional theory method and microkinetic model, study the following scientific issues: the reaction mechanism of MTP, the diffusion-surface reaction coupling characteristics from pore structure and acid interaction, the modulation principles of product distribution and Al state, and the effects of Al state on surface reaction and alkali modification. Master the intensification method of diffusion-surface reaction coupling and product distribution modulation. Solving the scientific problems behind poor catalyst stability and low propylene selectivity, guiding the design and synthesis of high-performance catalysts, will contribute to the diversification of technologies for catalytic conversion of methanol and the efficient and clean utilization of coal resources, with scientific significance and application prospects.