High utilization of methanol in toluene methylation using MFI zeolite nanosponge catalyst

Abstract

A highly mesoporous MFI zeolite nanosponge, which was composed of a disordered assembly of 2.5-nm thick zeolite frameworks, was synthesized using a meso- and micropore dual structure-directing surfactant. The zeolite nanosponge was investigated as a catalyst for toluene methylation by methanol. The results showed remarkably high toluene conversion and xylene yield, in comparison with the bulk zeolite counterparts. The high catalytic performance was attributed to the suppression of side reactions that could convert methanol to linear hydrocarbons. This suppression can be attributed to the fact that the dealkylation of polymethylbenzenes, which must take place before linear hydrocarbon formation, did not occur significantly in the zeolite nanosponge as compared to the case of bulk zeolites. In addition to the aforementioned high performance, the MFI zeolite nanosponge was also superior to the bulk MFI in terms of catalytic longevity.