Direct and Highly Selective Conversion of Bioethanol to Propylene Over Y-CeO₂ and Zeolite Beta Composite

A series of Y-CeO2/Beta composites with different Beta contents were prepared by an incipient impregnation method, followed by calcination at 650 degrees C. The Y-CeO2/Beta composites display excellent catalytic performance in the conversion of ethanol to propylene. In particular, the Y-CeO2/10%Beta catalyst with 10% zeolite Beta affords the highest propylene yield of 64.1%. The probe reactions suggest that the role of zeolite Beta in the Y-CeO2/Beta composite catalyst is to promote conversion of the acetone intermediate generated on Y-CeO2 oxide to 2-propanol via the MPV reaction as well as the subsequent dehydration of resulting 2-propanol to propylene, thereby enhancing the selective conversion of ethanol to propylene dramatically.