Heteroatom-Induced Fractal Growth for Hierarchical Zeolites

Hierarchical zeolites have been demonstrated to be advantageous in catalysis and adsorption applications due to facilitated diffusion without degrading its molecule sieving function. However, the direct synthesis of hierarchical zeolites in one step is still challenging. Herein, we report a simple one-step synthesis of single-crystalline hierarchical zeolites by fractal growth induced by the strong adsorption of heteroatom metal species on the initially formed crystals. This method is feasible in the presence of a variety of metal species (M–OH), which can develop a stronger hydrogen bond with Si–OH in comparison to that among Si–OH themselves, such as Ti, Sn, Ga, Nb, and V. Furthermore, the method is versatile as substantiated with several common zeolites, including ZSM-5, TS-1, and ZSM-11. Such a hierarchical zeolite exhibits significantly enhanced activity in polyethylene pyrolysis and a remarkably prolonged lifetime in methanol conversion to hydrocarbons due to facilitated diffusion.