Effect of Acid Type of Hierarchical ZSM-5 Zeolite on Cracking Reaction Performance
1. College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, Hangzhou 310027, China;
2. Institute of Zhejiang University-Quzhou, Quzhou 324000, China
Abstract：The hierarchical ZSM-5 zeolites prepared by using 3-propylaminotriethoxysilane (APTES) as soft template, were post treated with oxalic acid, hydrogen peroxide, or ammonium chloride as different modifying agents without introducing other elements. The effects of different treatment methods on the acid properties, pore structure and cracking reaction performance of n-heptane catalyzed over the zeolites were exhaustively investigated. The results of catalyst characterization showed that different post-treatment methods influenced greatly on the acid strength and acid type of zeolite. Oxalic acid treatment could significantly enhance the acid strength of zeolite, while hydrogen peroxide and ammonium chloride treatment increased the ratio of B acid to L acid. This might be because the free radicals and NH4+ produced by them could promote the conversion of L acid site to B acid site. The catalytic evaluation results indicated that the cracking activity of n-heptane over the zeolites could be improved by increasing the acid strength or the amount of B acid of zeolites, so as to improve the yield of light olefins.
HAO Jing1,YU Yueyang1,CHONG Mingben2 et al. Effect of Acid Type of Hierarchical ZSM-5 Zeolite on Cracking Reaction Performance [J]. 化学反应工程与工艺, 2021, 37(3): 226-234.
