Mesopore wall-catalyzed Friedel-Crafts acylation of bulky aromatic compounds in MFI zeolite nanosponge

Abstract

We investigated the effects of mesopore generation in a MFI zeolite when used as a catalyst in liquid-phase Friedel-Crafts acylation reactions of bulky aromatic compounds. For this investigation, we obtained an MFI zeolite with nanosponge morphology, following a seed-assisted hydrothermal synthesis route using C22H45-N+(CH3)(2)-C6H12-N+(CH3)(2)-C6H13. The zeolite nanosponge exhibited a narrow distribution of mesopore diameters centered at 4 nm, in which the mesopores were built with a disordered network of 2.5-nm thick MFI zeolite layers. This zeolite exhibited high catalytic performance in various acylation reactions, compared with bulk MFI zeolites, beta zeolite and mesoporous materials composed of amorphous aluminosilicates. The high catalytic performance corresponded to the strong Bronsted acid sites existing on the mesopore walls.