ALKYLATION OF TOLUENE WITH METHANOL OVER ZEOLITE-DISC CATALYST SYNTHESIZED VIA SOLID-STATE REACTIONS

ZSM-5 zeolite disc was synthesized by a new method in which reactions occurred in the solid state. The hydrogen form of the zeolite was prep ared by ion-exchange of the sodium ions of the disc-shaped pellet for hydrogen ions in hydrochloric acid solution. The catalyst thus prepare d was characterized by SEM, thermogravimetry, nitrogen adsorption and ammonia TPD. High paraxylene selectivity was observed for the new, dis c-shaped ZSM-5 zeolite catalyst in the alkylation of toluene with meth anol. This feature was attributed to the inherent character of the cat alyst, since its structure consisted of intergrown individual HZSM-5 c rystals forming secondary mesopores. This structural arrangement led t o a substantial decrease in the outer surface between the adjacent cry stals, the probability of secondary reactions therefore being suppress ed.