Dry reforming of CH4 on Rh doped Co/Al2O3 catalysts

Abstract

The reforming of methane with carbon dioxide has been investigated at 773K on 10% Co/Al2O3 promoted with Rh and calcined at different temperatures. In addition, the dissociation of carbon dioxide and methane has also been examined. TPR and XPS results revealed that during the pre-treatment of the catalysts the Co reduced only partially but Rh promoted this process. The dissociation of carbon dioxide occurred most easily on Rh containing catalysts in the presence of methane. Rh promoted Co/Al2O3 was found to be more active in the CO2+CH4 reaction than the Co/Al2O3. The amount and the reactivity of surface carbon significantly depended on the calcination temperature of the catalysts. It influenced oppositely the amount of surface carbon on 0.1% Rh+10% Co/Al2O3 and on 10% Co/Al2O3. On 10% Co/Al2O3 (700) the amount of carbon residue is higher than on 10% Co/Al2O3 (500), but on the Rh containing samples the trend is the opposite. We may suppose that the different structures of the catalysts formed in the presence of Rh and at different calcination temperatures resulted in the different catalytic behaviours.