Catalytic activity of a zeolite disc synthesized through solid-state reactions

ZSM-5 zeolite in a disc-shaped form was synthesized by a new method in which reactions occurred in the solid state. The proton form of the zeolite was prepared by ion exchange of the sodium ions of the disc-shaped pellet in hydrochloric acid solution. The catalyst prepared was characterized by SEM, thermogravimetry, nitrogen adsorption and ammonia TPD. High p-xylene selectivity was observed for the new disc-shaped ZSM-5 zeolite catalyst in the alkylation of toluene with methanol. This catalytic feature was attributed to the inherent character of the zeolite, since its structure consisted of inter-grown individual HZSM-5 crystals forming secondary mesopores which promote the high gas permeability of the zeolite disc. (C) 1998 Elsevier Science B.V. All rights reserved.