MgO–Al2O3 Mixed Oxides-Supported Co–Mo-Based Catalysts for High-Temperature Water–Gas Shift Reaction

Abstract

MgO–Al2O3 mixed oxides were prepared and used as the support of Co–Mo-based water–gas shift reaction (WGSR) catalysts. X-ray diffraction (XRD) characterization showed that the MgO–Al2O3 mixed oxides support is composed of MgO, γ-Al2O3, and magnesia–alumina spinel. The MgO–Al2O3 mixed oxides-supported Co–Mo-based catalysts exhibited high shift activity at high temperature (360–450 °C) and high stability. The addition of potassium enhanced the activities but affected adversely the stabilities of Co–Mo-based catalysts. ESR characterization shows that the Mo5+ species are not connected with the WGSR activity. Magnesium in the support may be closely related with the formation of formate species intermediate for the WGSR.