High Stability Catalyst for Butene Cracking with Ultrathin ZSM-5 Nanoplates
Haitao Zhang, Zhixiang Xi, Haiyan Wang, Jiaxing Zhang, Ajuan Zhou, Renwei Xu, Anfeng Zhang, Xinwen Guo
Abstract
Catalytic cracking of light hydrocarbons is an attractive route for light olefin production. However, the poor stability of catalysts has impeded their practical application in industry, therefore more attention should be given to catalyst design to break the bottleneck of this technology. To solve this issue, ultrathin ZSM-5 nanoplates with high silicon content (Si/Al > 200) were synthesized and assessed for the catalytic cracking of C 4 olefins. The obtained ZSM-5 nanoplates presented high selectivity toward light olefins up to 64.4% with n-butene conversion of 71.4% at 550 °C and WHSV of 30 h –1 . Notably, no deactivation was observed during 120 h time-on-stream (TOS) operation. The effects of the Si/Al ratio and b -axis thickness of ZSM-5 zeolites were investigated to optimize their performance in C 4 catalytic cracking. The catalyst lifetime of silicon-rich ZSM-5 nanoplates with b -axis thickness of 20–30 nm is about 3 times longer that of the plate-like ZSM-5 reference because of the increased acid sites and intergranular mesopores. This work opens an attractive avenue for the development of stable and active catalysts for the catalytic cracking of C 4 olefins.