The CO Methanation Over The Rh and Ru Promoted NiO-CeO2-ZrO2 Catalysts

In this study, Rh and Ru promoted NiO-CeO2-ZrO2 catalysts were prepared with different Rh and Ru loadings (3, 4, 5 (wt.%)) by using two different methods. N-2 phsisorption, X-Ray diffraction, scanning electron microscope with energy-dispersive (SEM-EDX) techniques were used in order to characterize the catalysts. Catalytic activities of the catalysts were tested for CO methanation. The selective CO methanation catalytic activity tests were made over the most active catalysts. The effect of the Rh and Ru loading and preparation method on the CO methanation was discussed. The Ru and Rh have different effect on the surface areas of the catalysts and identifiable peaks for Rh and Ru not observed from the XRD analysis. Because of the low ratio of Rh and Ru in catalysts structures, both Ru and Rh containing catalysts gave similar CO methanation activity results. The 50% conversion temperatures of the 3% Ru/NiO-CeO2-ZrO2 catalysts which were prepared by the co-precipitation and surfactant assisted coprecipitation are 191 degrees C and 185 degrees C, respectively. Selective CO methanation was made over the 3% Ru/NiO-CeO2-ZrO2 catalysts. Catalysts gave good activity until 300 C. Because of the reversed water gas shift reaction activities of the catalysts were decreased after this temperature.