Synthesis of ZSM-22 Zeolite Nanosheets with Improved Stability in the Catalytic Conversion of Methanol to Hydrocarbons

The synthesis of zeolite nanosheets is an effective strategy to obtain advanced catalysts with enhanced catalytic performance due to the improved diffusion properties. ZSM-22 zeolite nanosheets (F-ZSM-22, U-ZSM-22) with a controllable orientation and a thickness of less than 20 nm were obtained through hydrothermal crystallization by introducing NaF or urea into the synthetic system of conventional ZSM-22 (C-ZSM-22). In the presence of both NaF and urea, a zeolite nanosheet (FU-ZSM-22) with a decreased width was synthesized. In comparison with C-ZSM-22, all ZSM-22 nanosheets displayed better diffusion properties. On testing catalysts in the methanol-to-hydrocarbon reaction, ZSM-22 nanosheets showed better stability than C-ZSM-22, and FU-ZSM-22 was the best catalyst.