The preparation of core-shell-like zeolite by diffusion controlled chemical etching

Yanfeng Shen , Mingrui Xu , Jingyang Li (1) , Zhengxing Qin (2) , Chunzheng Wang (2) , Svetlana Mintova (3) , Xinmei Liu (2)

1 CATAS - Chinese Academy of Tropical Agricultural Sciences
2 China University of Petroleum
3 LCS - Laboratoire catalyse et spectrochimie

The present work reports on the preparation of core-shell-like zeolites with Si-rich mesoporous shell. This is achieved by diffusion controlled chemical etching of zeolite crystals with a mixture containing oxalic acid and ammonium fluoride (OA-NH 4 F). The OA-NH 4 F served as a bifunctional etchant extracting both surface Si and Al and further dealuminating the periphery of the zeolite crystals. The fast dissolution kinetics and the relatively slow intra-crystalline diffusion of the OA-NH 4 F etching solutions resulted in a distinct core-shell-like structure with porous and Si-rich shell keeping the unique advantages of single crystals with interconnected micro-and mesopores.

Domaines: Chimie

Yanfeng Shen, Mingrui Xu, Jingyang Li, Zhengxing Qin, Chunzheng Wang, et al.. The preparation of core-shell-like zeolite by diffusion controlled chemical etching. Inorganic Chemistry Frontiers, 2021, 8 (8), pp.2144-2152. ⟨10.1039/D0QI01417F⟩. ⟨hal-03416063⟩