Low-cost preparation of plate-like ZSM-5 zeolite and its application in 1-butene cracking

A low-cost seed-assisted route was developed to synthesize plate-like ZSM-5 zeolite. • The key factors governing the synthesis were systematically investigated. • The minimum thickness of the b -axis could reach ∼50 nm. • Reducing b -axis thickness of ZSM-5 zeolite improves its catalytic performance in 1-butene cracking. Plate-like ZSM-5 zeolites, featuring a shortened b -axis that effectively alleviates micropore diffusion limitations, display significant advantages in many catalytic reactions. However, current syntheses rely heavily on expensive organic structure-directing agents (OSDAs) and sometimes toxic fluoride reagents, making a low-cost synthesis route highly desirable. To fulfill this goal, we propose a seed-assisted strategy combined with γ-aminobutyric acid as an additive, which effectively reduces the consumption of OSDA. By tuning key parameters, the b -axis thickness can be precisely controlled during synthesis, the minimum thickness could reach ∼50 nm. Plate-like ZSM-5 zeolites with similar physicochemical properties but different b -axis thicknesses were tested in 1-butene catalytic cracking. Reducing the b -axis thickness could effectively enhance the catalytic activity and stability, the sample (P-6%) with the thinnest b -axis thickness exhibiting the best performance. TGA analysis of spent catalysts confirmed the superior coke tolerance of P-6%, and in situ UV-Vis spectroscopy investigation of organic intermediates formed during the reaction further confirmed its excellent activity and stability. Download: Download high-res image (256KB) Download: Download full-size image