Utilization of CO2, which is the main contributor to the global climate change is one of the means to produce useful chemicals and fuels while at the same time reduce CO2 concentration in the atmosphere. Ruthenium (Ru) was chosen as the probe catalyst in carbon dioxide hydrogenation based on its ability to selectively enhance methanation reaction. Ru supported on YSZ solid electrolyte (Ru/YSZ) was modified with alkaline earth metal promoters i.e. calcium (Ca) and magnesium (Mg) at low coverage (0.16%). It was found that Ca-modified system is more favorable to enhance the catalytic activity and selectivity of reaction towards methane production compared to Mg-modified system, perhaps due to the higher basicity of Ca.
