CO2/CO methanation over Ru and Ni supported γ-Al2O3: A study on the effect of the stoichiometry of reactant gases

CO<inf>2</inf> and CO conversion to methane serves as a dual process as it helps in the depletion of CO and CO<inf>2</inf> released in the atmosphere due to anthropogenic reasons and gives us by-products of high calorific value. Herein, we have studied the CO<inf>2</inf> and CO methanation reaction at different stoichiometry using two supported catalysts: Ru/γ-Al<inf>2</inf>O<inf>3</inf> and Ni/γ-Al<inf>2</inf>O<inf>3.</inf> The catalysts are prepared using hydrazine reduction, and the methanation reaction is tested using temperature-programmed reactions by varying the stoichiometric moles of hydrogen to study the effect on conversion and methane selectivity. Stoichiometry effect is important to study in cases where hydrogen is present in lesser quantities than the stoichiometry. In addition, the long-term stability is also studied for both catalysts for 40 hours and spent catalysts were characterized by the Thermogravimetric analysis (TGA), O<inf>2</inf>-Temperature programmed oxidation (O<inf>2</inf>-TPO) and X-ray photoelectron spectroscopy (XPS).