One-pot synthesis of hierarchical mordenite and its performance in the benzylation of benzene with benzyl alcohol

Abstract

Hierarchical mordenite with micropores and mesopores was one-pot synthesized through a soft-templating method using a special diquaternary ammonium-type surfactant as a mesoporogen. The obtained samples were characterized by XRD, N2 physisorption, SEM, TEM, TG-DTG, 27Al and 29Si NMR spectroscopy, and NH3-TPD techniques. The catalytic performance of the hierarchical mordenite compared to that of conventional mordenite and mesoporous AlMCM-41 material was evaluated in the benzylation of benzene with benzyl alcohol. The results show that the hierarchical mordenite is highly crystalline and possesses large mesopore volume and strong acidity. Moreover, the prepared hierarchical mordenite catalyst is high-efficiency for the conversion of benzyl alcohol into diphenylmethane due to the superior mass transfer ability and largely accessible acid sites. The apparent reaction rate constant for HMOR is 23 times that for CMOR and 8 times that for AlMCM-41. These results suggest that hierarchical zeolites with mesoporosity and strong acidity may be the ideal catalysts in reactions involving large molecules.