Controllable Direct Synthesis of FER Zeolite Nanosheets by a Dual-Template for an Efficient Performance in LDPE Cracking

Abstract

Nanoscale zeolites have been reported to solve the problems of reducing diffusion limitations and enhancing catalytic performance. Herein, pure silica and aluminosilicate ferrierite (FER) nanosheets were synthesized employing imidazolium with the assistance of CTAB. The indispensable role of CTAB in the zeolite synthesis and the impact on the sample properties, especially the external surface area, are highlighted. Compared with pure silica FER samples, aluminosilicate FER zeolites show a thinner morphology. By control of the amount of Al, the thickness of the samples can be adjusted. Samples with different Si/Al ratios exhibit different pore properties, thermal characteristics, and acidities. The catalytic performances of Al-FER zeolites were evaluated by low-density polyethylene cracking with the lowest temperature of 353 °C corresponding to the 50% conversion of a pure polymer, better than the previously reported hierarchical zeolite ferrierite nanosheets. This work verifies the synergistic effect of CTAB in the synthesis of a nanoscale zeolite, while the controllable synthesis strategy opens the way to constructing other nanoscale zeolites with excellent catalytic activity for bulk molecules.