LAUSR

Abstract CO2 emitted from utilization of fossil fuels has a major contribution to greenhouse effect, turning it into a critical environment issue. Its use as raw material to methanation is gaining much attention, both as a renewable energy source and as a chemical precursor. Ni-Cu/SiO2 catalysts prepared by wet impregnation were tested for the CO2 methanation in a fixed bed reactor at 1 atm, GHSV of 60000 mL.(gcat.h)−1, H2/CO2 = 4, in the range of 200–400 °C. The physicochemical properties of the catalysts were characterized by XRD, N2 adsorption-desorption, TGA-DTA, TPO and TPR. It was found that higher Ni loadings improved catalyst activity and CH4 selectivity, while Cu promotion dramatically increased CO selectivity, which indicates favoring of the RWGS reaction. The best results were obtained by Ni15 catalyst, with 55% of CO2 conversion and 96% of CH4 selectivity at 350 °C. Cu-promoted samples highly favored CO selectivity in the order of 70–80%. Furthermore, the presence of Cu increased slightly the resistance of catalyst to sintering and decreased the CO2 conversion. All catalysts showed high stability during 300 min in the reaction at 400 °C.