Regulating acid properties of ZSM-5 nanosheets by Fe incorporation towards high-performance alkylation of benzene with methanol

A clear understanding of the acidity-activity relationship is an important prerequisite for designing functional materials in alkylation of benzene with methanol. Herein, a series of b -axis-oriented [Fe/Al]-MFI nanosheets with similar thickness but varied acidities were prepared by tuning Fe incorporation to systematically study the effect of acidity on their alkylation performance. Comprehensive physiochemical studies demonstrate that tetrahedral framework type Fe species are dominated. The incorporation of Fe significantly weakens the strong acid strength of zeolite thus endowing the samples with proper acidity, consequently showing a strong inhibition effect on the by-product ethylbenzene. Moreover, a long-term stable operation (>300 h) is further achieved over the [Fe]-S-1 nanosheets by optimizing the content of framework Fe. This work elucidates the important relationship between acidity and alkylation activity.