The Effect of Si on CO2 Methanation over Ni-xSi/ZrO2 Catalysts at Low Temperature

A series of Ni-xSi/ZrO2 (x = 0, 0.1, 0.5, 1 wt%, the controlled contents Si) catalysts with a nickel content 10 wt% were prepared by co-impregnation method ZrO2 as support and Si promoter. The effect different amounts on catalytic performance was investigated for CO2 methanation stoichiometric H2/CO2 molar ratio (4/1). characterized BET, XRF, H2-TPR, H2-TPD, H2-chemisorption, CO2-TPD, XRD, TEM, XPS, TG-DSC. It found that adding appropriate amount could improve Ni/ZrO2 catalyst at low reaction temperature (250 °C). Among all studied, Ni-0.1Si/ZrO2 showed highest activity, H2 conversion 73.4% 72.5%, respectively yield CH4 72.2%. Meanwhile, high stability no deactivation within h test. Adding enhance interaction between Ni ZrO2, increase dispersion, active sites including surface Ni0, oxygen vacancies, strong basic surface. These might be reasons activity selectivity catalyst.