Methanation of carbon dioxide over the LaNiO3 perovskite catalysts activated under the reactant stream

In this study, LaNiO3 perovskite catalysts were prepared by citrate method and used for carbon dioxide (CO2) methanation. The catalysts were activated at different temperatures (400–700°C) under the reactant stream. The activation led to the formation of small metallic nickel particles and hexagonal lanthanum oxocarbonate (La2O2CO3). Ni0 was highly dispersed and enveloped by La2O2CO3, which was responsible for the high catalytic activity and stability of the LaNiO3 perovskite catalysts even at high temperature (400–500°C). The X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and H2-temperature-programmed desorption measurements illustrated that La2O2CO3 generated from the activation might play an important role in the methanation of CO2.