Synthesis of 2D MFI zeolites in the form of self-interlocked nanosheet stacks with tuneable structural and chemical properties for catalysis
Tóm tắt
This study explores a facile synthesis method by simply changing the type of precursor cations or anions to regulate the nanosheet stack size of mesoporous 2D MFI zeolites while preserving the ‘self-interlocked ordered nanosheet stack’ (SI-ONS) microstructural characteristics. The important roles of precursor cations and anions in controlling the structure and hence chemical properties of the 2D MFI zeolites are demonstrated and the corresponding mechanisms are explained. The ability to facilitate microporous MFI framework development followed the order Na+ K+ >Rb+ >Cs+ and SO4 2− >NO3 − >Cl−. The cations and anions showed little effect on the number and strength of strong acid sites, but clearly influenced their hydrothermal stability. The hydrothermal stability of strong acid sites in the resulting 2D MFI zeolites followed the order Na+