Effect of the Structural Properties of Hierarchical Al-BEA Zeolites on the Catalytic Activity in Benzene Alkylation with Propylene

Abstract Hierarchical Al-BEA zeolites were prepared by hydrothermal treatment of the reaction mixture containing highly dispersed Aerosil A-300 as a silicon source without alkali metal cations and additional templates for the mesopore formation. The material with the most developed mesoporosity is formed by concentrating the reaction mixture to the H 2 O/Si molar ratio of 5.5. The catalytic properties of the hierarchical materials prepared and commercial zeolite in benzene alkylation with propylene were studied. The samples tested exhibit 88–91 wt % cumene formation selectivity. The hierarchical zeolite prepared from the reaction mixture with the H 2 O/Si ratio of 5.5 ensures the highest propylene conversion and exhibits the highest stability in alkylation. This zeolite has the highest mesopore volume, the highest external specific surface area, high concentration of strong Brønsted acid sites, and relatively low content of Lewis acid sites.