Hierarchical Zeolites and their Catalytic Performance in Selective Oxidative Processes

Hierarchical ZSM-5 zeolites prepared using a simple alkali treatment and subsequent HCl washing are found to exhibit unprecedented catalytic activities in selective oxidation of benzyl alcohol under microwave irradiation. The metal-free zeolites promote the microwave-assisted oxidation of benzyl alcohol with hydrogen peroxide in yields ranging from 45-35% after 5min of reaction under mild reaction conditions as well as the epoxidation of cyclohexene to valuable products (40-60% conversion). The hierarchically porous systems also exhibited an interesting catalytic activity in the dehydration of N,N-dimethylformamide (25-30% conversion), representing the first example of transition-metal free catalysts in this reaction.