Effect of Ruthenium promotor ratio on Ni/Y2O3 Based Catalysts for CO2 Methanation Reaction

CO2 is one of the main contributors to the greenhouse effect and hence to climate change, there is a growing interest in its use as a feedstock in chemical processes.CO2 methanation has recently gained renewed interest.A series of nickel supported on yttrium oxide and promoted with different ratios of ruthenium was prepared by the wet impregnation method.The developed Ru-Ni/Y2O3 structure was then characterized using N2 adsorption-desorption isotherm, XRD, XPS, TPR, and HTEM techniques to evaluate the surface, crystal phase, and morphology.The catalytic test was conducted with the use of a fixed-bed tubular reactor under atmospheric pressure.Temperature of catalytic performance was 350 °C with a supply of CO2/H2/Ar with a ratio of 1/4/5 and a total flow rate of 200 ml/min.The main products of the reaction were CH4 and water.Traces of carbon monoxide was present among the product.The methane yield was reached 16.4%, 14%, 17.74%, and 14.24% over Ni/Y2O3, 1Ru-Ni/Y2O3, 5Ru-Ni/Y2O3, and 10Ru-Ni/Y2O3 catalysts respectively.The amount of promoter was stated to have affected the catalytic activity but huge numbers usually of promoters diminishing catalytic activity due to active site coverage.However; the increase in Ru loading in the 10Ru-Ni/Y2O3 sample decreased the catalytic activity towards methanation due to the Ru-precursor used (RuCl3.nH2O) in this study.The residual chloride ions form a barrier between the support and the metal, and thus both inhibit CO and hydrogen chemisorption on the catalyst surface.