微孔分子筛限域Pt基丙烷脱氢催化剂制备的研究进展

Synthesis research progress of microporous molecular zeolites confined Pt-based catalysts for direct dehydrogenation of propane

丙烯是化工生产中的重要中间体,利用廉价天然气中的丙烷无氧脱氢高选择性制丙烯是当前研究的热点。近年来,分子筛限域的Pt基丙烷脱氢催化剂因其高活性和高稳定性被广泛研究。如何利用高温稳定、高孔隙率、结构均一的分子筛限域高分散贵金属是设计和制备高效丙烷脱氢催化剂的关键。总结了非强酸性分子筛限域Pt金属颗粒的原位封装空间限域和特殊位点限域策略。其中,原位封装空间限域策略是在分子筛合成过程中加入金属前驱体及适宜的配体保护剂,使Pt金属离子均匀地分布在分子筛凝胶中,经高温焙烧后锚定在孔道中;特殊位点限域策略是通过强金属载体相互作用限域Pt金属颗粒。2种策略能有效抑制高温烧结,提高贵金属Pt原子的利用率和结构稳定性。

Propylene is an important intermediate in chemical production.Anaerobic dehydrogenation of propane from cheap natural gas to produce propylene with high selectivity is a research hotspot at present.In recent years,molecular sieves confined Pt based catalysts for propane dehydrogenation have been widely studied because of their high activity and stability.How to use the molecular sieves with high temperature stability,high porosity and uniform structure for confining highly dispersed noble metals is the key to design and prepare efficient catalysts for propane dehydrogenation.In this paper,we summarize the in-situ packaging space confinement and special site confinement strategies to confine Pt metal particles using non-strongly acidic molecular sieve.In situ packaging space confinementi through adding metal precursors and suitable ligand protectant in the process of molecular sieve synthesis,the Pt ions are distributed in the molecular sieve gel and then evenly confine in the channel after high temperature calcination.The special site confinement strategy is to confine Pt metal particles through strong interaction between metal and supports.The above two strategies effectively inhibit high-temperature sintering and improve the atomic utilization and structural stability of precious metal Pt.