DISPROPORTIONATION OF TOLUENE OVER A HY-BETA-AIF3-CU CATALYST .1. PREPARATION AND CHARACTERIZATION

The preparation, characterization, and testing of a catalyst consisting of 72 wt% HY zeolite, 18 wt% β-AlF3, and 10 wt% Cu for the conversion of toluene into benzene and xylenes are described. The effect of β-AlF3, copper, and the activation temperature on the activity, selectivity, and stability of the catalyst were investigated. The results demonstrate that the catalyst shows satisfactory performance and reveal that 500°C is its optimum activation temperature. Texture determinations and activity measurements suggest that disproportionation activity is localized in the transitional pores of the catalyst and that the micropores only serve to collect heavy reaction products which would otherwise lead to deactivation. The results of ammonia adsorption combined with the effect of activation temperature on activity indicate that Brønsted acid sites formed during activation are responsible for the activity. It appears that only about 10% of the surface sites on freshly activated catalyst are acidic. © 1979 Academic Press, Inc. All rights reserved.