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 prepared by ion-exchange of the sodium ions of the disc-shaped pellet for hydrogen ions in hydrochloric acid solution. The catalyst thus prepared was characterized by SEM, thermogravimetry, nitrogen adsorption and ammonia TPD. High paraxylene selectivity was observed for the new, disc-shaped ZSM-5 zeolite catalyst in the alkylation of toluene with methanol. This feature was attributed to the inherent character of the catalyst, since its structure consisted of intergrown individual HZSM-5 crystals forming secondary mesopores. This structural arrangement led to a substantial decrease in the outer surface between the adjacent crystals, the probability of secondary reactions therefore being suppressed.
- Shape selectivity
ASJC Scopus subject areas
- Process Chemistry and Technology