Wheel-like Mordenite Nanoassemblies with Shortened Channel Lengths for Improved Catalytic Performance in Dimethyl Ether Carbonylation
Wenrong Liu, Yaquan Wang, Lingzhen Bu, Yaqiong Zhi, Zhiqiang Wang, Mengyao Yang, Kailiang Chu, Yitong Huang, Niandong Guo, Liping Qu, Juncai Sang
Abstract
To achieve a better catalytic performance, it is of great interest to synthesize nanosized zeolites with reduced internal diffusion limitations. Herein, c -axis shortened wheel-like mordenite nanoassemblies were synthesized. The crystal growth along the [001] direction was successfully inhibited with K + cations as structure breaking agents. The wheel-like crystal is 1.5–2 μm in diameter and 200–300 nm in thickness. The growth of such a unique structure underwent a nonclassical crystallization process including the generation of amorphous worm-like particles and formation of wheel-like crystallites followed by a – b plane oriented growth of the crystals. The obtained MOR wheel-like assemblies possessed larger surface area and external surface area, displayed better mass transfer properties, and exhibited much better catalytic performance than MOR spheroid-like assemblies and conventional bulk MOR zeolite in dimethyl ether (DME) carbonylation reaction, with two and a half times higher the conversion of DME than the bulk MOR, although these samples had identical Si/Al ratios and acid properties. This work provides a simple route to control the zeolite morphology by alkali metal cations and brings forward an effective strategy to prepare zeolite materials with improved catalytic performance.