Mesoporous MFI Zeolite Nanosponge as a High-Performance Catalyst in the Pechmann Condensation Reaction

A zeolite nanosponge possessing MFI framework type was hydrothermally prepared by a seed-assisted synthesis method using C22H45–N+(CH3)2–C6H12–N+(CH3)2–C6H13 as a structure-directing agent. The nanosponge morphology was composed of a three-dimensional disordered network of MFI nanolayers with 2.5 nm thickness supporting each other. Catalytic performance of the MFI nanosponge was investigated in the Pechmann condensation of bulky reactants (pyrogallol and resorcinol) with ethyl acetoacetate and compared with conventional zeolites MFI, BEA, and USY) and also layered MFI, pillared MFI, and self-pillared MFI. The investigation revealed outstanding catalytic performance of the MFI nanosponge, which can be attributed to the contribution of strong acid sites located on the external surfaces accessible for the reaction of bulky reactants.