Enhancement of CO2 Methanation over La-Modified Ni/SBA-15 Catalysts Prepared by Different Doping Methods

A new, highly active Ni-La2O3/SBA-15(C) catalyst for CO2 methanation was prepared using a citrate complex method, where the formed LaNiO3 with perovskite structure was a key precursor. The physicochemical properties of the catalyst, as-prepared and spent, and its catalytic performance were analyzed in detail and compared with catalysts prepared through a typical wet impregnation method. 10 wt % nickel with lanthanum in the molar ratio of 1:1 was used to prepare the La-modified catalysts. It was found that the La2O3 doping methods had a noticeable effect on the structures of the catalysts and their catalytic performances. Ni-La2O3/SBA-15(C) showed a high dispersion of Ni with a small particle size less than 5 nm, which is one-third of the particle size of that prepared by impregnation. Decent catalytic performance was achieved with a CO2 conversion of 90.7% and CH4 selectivity of 99.5% at 320 °C. Due to the specific perovskite structure of LaNiO3, the interaction between La and Ni was intensified, thus enh...