Investigation of carbon dioxide methanation over ceria based catalysts

Abstract

The recycling technology by the catalytic conversion is one of the most promising techniques for the CO2 treatment of gas burning power plant flue gases. The methanation of CO2 to valuable product of CH4shows significant environmental and economic benefits since the methane gas production can be used as a fuel to run the turbine for electricity generation. In addition, a highly basic catalyst such as ceria which has excellent redox properties is an effective material which could enhance carbon dioxide adsorption on the catalyst surface but has not been widely explored. Therefore, this research is focused on the development of ceria based catalysts by impregnating Ce to Ru/Mn/Al2O3 catalyst. From the catalytic testing, the addition of Ce to Ru/Mn/Al2O3 as based catalyst was found to be appreciably more active for promoting the CO2methanation reaction. Further investigation of the Ru/Mn/Ce/Al2O3 catalysts on the ceria loading and calcination temperature can significantly affect the catalytic performance. The optimum conditions were achieved with 65 wt% of cerium loading and calcination temperature of 1000°C which gave 97.73% CO2 conversion with 91.31% of methane formation at reaction temperature of 200oC. Meanwhile, only 30.52% methane was formed from 30.72% CO2 conversion over Ru/Mn-65/Al2O3 catalyst. The high activity of Ru/Mn/Ce-65/Al2O3 catalyst can be ascribed to its high surface area caused by the production of new active sites on the catalyst surface since the morphology of the catalyst had transformed to look like staghorn coral morphology. Furthermore, incorporating the Ce towards Ru/Mn-65/Al2O3 catalyst had induced the formation of Al2O3 with different crystalline phase (from rhombohedral to orthorhombic phase) and formation of MnO2 and Mn2O3