γ-aminobutyric acid-assisted fabrication of plate-like ZSM-5 zeolite for efficient propylene production from methanol conversion

Plate-like ZSM-5 zeolites offering a short diffusion pathway along the b-axis are highly desirable catalyst for methanol to propylene (MTP) reaction. Herein, we successfully developed a simple synthetic strategy toward reducing the thickness along b-axis of ZSM-5 zeolite by combing a preliminary aging process and the addition of γ-aminobutyric acid. In particular, γ-aminobutyric acid adopted as a zeolite growth modifier was firstly proposed to prepare plate-like ZSM-5 zeolite with a short thickness of b-axis, and the minimum thickness can reach ∼50 nm. The shortened diffusion length in plate-like ZSM-5 zeolites could significantly improve the transport efficiency of molecules to and away from the active sites and finally leads to a better catalytic performance in the MTP reaction. Particularly, the plate-like ZSM-5 zeolite with an impressively shortened diffusion length (P-ZSM-5–0.3#0.3) displayed greatly improved catalytic performances (higher propylene selectivity and longer lifetime) than conventional ZSM-5 with a thicker dimension along the b-axis.