Evidence of multi-component interaction in a V–Ce–HUSY catalyst: Is the cerium–EFAL interaction the key of vanadium trapping?

Abstract

Cerium was introduced into a USY-based catalyst using three methodologies: precipitation, impregnation and ionic-exchange. The CeUSY catalysts were poisoned with vanadium and deactivated with steam at 1073 K. The catalysts were characterized by HRTEM-EDX, FTIR, BET, EPR, XPS and by the test of catalytic dehydration of 2-propanol. The results indicate that the presence of a V–Ce–EFAL multi-component interaction strongly affects the vanadium reduction and its migration, also inhibiting the cerium oxide sintering. HRTEM measurements with analysis of energy dispersive X-rays on the impregnated catalyst revealed a preferential V–Ce interaction in the extra framework aluminum (EFAL) domains. The FTIR results strongly support that this V–Ce–EFAL interaction occurs via hydroxyl groups. The impregnated catalysts showed greater vanadium tolerance than catalysts prepared by other methodologies of cerium introduction.