Catalysts of Ni/SiO2 and Ni-La/SiO2 were prepared using the incipient-wetness impregnation method. The prepared catalysts were used to produce syngas from a combined reaction of CO2 reforming and partial oxidation of methane in a fluidized-bed reactor. Ni/SiO2 exhibited excellent resistance to carbon deposition and stable catalytic performance upon promotion with La2O3. The promoter (La2O3) increased the dispersion of nickel crystallites and prevented their sintenrig during the reaction. Consequently, the adsorption abilities of oxygen and CO2 were enhanced and the rate of carbon elimination was therefore increased. Temperature-programmed reduction and X-ray diffraction characterization revealed that the promotion effect of La2O3 originated from its strong interaction with nickel.