Synthesis of hierarchical ZSM‐5 microspheres with superior performance for catalytic methanol‐to‐olefin conversion

作者：Yali Zhang, Kai Zhang, Chao Shang, Xiaoning Wang, Lei Wu, Guoqing Huang, Hao Wang, Qiming Sun, Xiao Dong Chen, Zhangxiong Wu · 发表于：AIChE Journal · 年份：2022 · DOI：10.1002/aic.17913 · 被引用次数：16 · 研究领域：Zeolite Catalysis and Synthesis、Catalytic Processes in Materials Science、Catalysis and Hydrodesulfurization Studies

Abstract Methanol‐to‐olefin (MTO) conversion on zeolites has encountered severe coke deposition and rapid deactivation. Creating different levels of porosity is essential to mitigate such issues. Herein, we demonstrate a facile and green strategy to synthesize uniform and hierarchically macro/mesoporous ZSM‐5 microspheres by combining spray‐freeze drying and steaming‐assisted crystallization (SAC). The structure, crystallinity, and porosity of the zeolite microspheres are controlled by adjusting the water/gel mass ratio and time in the SAC process. The structure evolution during the SAC process is revealed. In the catalytic MTO reaction, the representative hierarchically porous ZSM‐5 catalyst exhibits superior catalytic performance. At a very high weight hourly space velocity of 18 h −1 , it shows a dramatically prolonged lifetime (47 h at >99% conversion) and much‐improved selectivity to ethylene and propylene compared with the conventional microporous ZSM‐5 and nano‐sized ZSM‐5. The enhanced performance is originated from the hierarchical structure and suitable acidity of the ZSM‐5 microspheres.