Enhanced Catalytic Performances by Desilication and Subsequent Steam Treatment of ZSM-5 Zeolite

Controlled desilication of ZSM-5 zeolite increases the acid site density of its acid form. A subsequent treatment with steam at 300 °C results in a material with single-sized and slightly larger micropores when compared to the parent zeolite. This is likely the cause of a second increase of the yields of MTBE (methyl terbutyl ether) and ethylene when the steamed desilicated zeolite is used as catalyst in the MTBE synthesis and ethanol dehydration, respectively. Steam appears to be capable of “healing” the zeolite framework at a temperature much lower than that normally required when the desilicated ZSM-5 zeolite is solely heated in air.