Catalytic conversion of methane and CO2 to synthesis gas over a La2O3-modified SiO2 supported Ni catalyst in fluidized-bed reactor

In this contribution, a commercial spherical SiO2 was modified with different amounts of La2O3, and used as the support of Ni catalysts for autothermal reforming of methane in a fluidized-bed reactor. Nitrogen adsorption, XRD and H2-TPR analysis indicated that La2O3-modified SiO2 had higher surface area, strengthened interaction between Ni and support, and improved dispersion of Ni. CO2-TPD found that La2O3 increased the alkalescence of SiO2 and improved the activation of CO2. Coking reaction (via both temperature-programmed surface reaction of CH4 (CH4-TPSR) and pulse decomposition of CH4) disclosed that La2O3 reduced the dehydrogenation ability of Ni. CO2-TPO, O2-TPO (followed after CH4-TPSR) confirmed that only part amount of carbon species derived from methane decomposition could be removed by CO2, and O2 in feed played a crucial role for the gasification of the inactive surface carbons. Ni/xLa2O3-SiO2 (x = 10, 15, 30) possessed high activity and excellent stability for autothermal reforming of methane in a fluidized-bed reactor.