Methanation of Carbon Monoxide with Water over Supported Rhodium Catalysts.

Abstract

The formation of methane in the reaction of CO and H₂O over Rh supported on ZrO₂, Al₂O₃, TiO₂, SiO₂ and MgO was examined. The high activity was achieved over Rh/ZrO₂ and Rh/TiO₂ at 300°C and CO dissociation ability of the catalyst was concluded to be an important factor to obtain high activity. At low temperature (c. 200°C), CO was not hydrogenated effectively but CO₂ formed by the water gas shift reaction was hydrogenated after the conversion of CO into CO₂ was completed. The formation of CH₄ appears to occur through the water gas shift reaction, followed by the hydrogenation of carbonaceous species formed by the dissociation of CO or CO₂.