Effect of Different Supports on Activity of Nickel Catalysts in Water-gas Shift Reaction

Water gas shift is an exothermic reaction used to enhance hydrogen content and reduce CO concentration in synthesis gas. In this study, the effect of nickel catalysts supported on CeO2, Al2O3, TiO2, ZrO2, and SiO2 on carbon monoxide conversion and producing carbon dioxide was investigated. Nickel was loaded taking the advantage of wet impregnation. In order to investigate the structure and morphology of the as prepared catalysts, BET, XRD, SEM, and TEM tests were employed. The test reactor was a tabular reactor made of quarts. Total flow rate was considered 300 ml/min and 150 mg mass of catalyst was loaded in the reactor. The performance of catalysts was investigated in the temperature range of 300-500 °C and at steam to carbon monoxide ratio of 1, 2, and 4. In addition, catalyst stability test was performed for 570 minutes. The results indicated that both catalysts had the maximum activity at 450 °C. The most conversion of CO and CO2 selectivity was observed for Ni/CeO2 due to high oxygen capacity of cerium oxide. The optimized loading of nickel was 13% of catalyst weight. Increasing steam to carbon monoxide ratio leaded to enhance activity.