Ni-CaZrO3 with perovskite phase loaded on ZrO2 for CO2 methanation

CO2 methanation has emerged as a promising strategy for the greenhouse gas CO2 utilization and storage of hydrogen. However, achieving low temperature activity and high temperature stability remains challenging due to the sintering of Ni-based catalysts. To address these limitations, this study introduces a Ni-CaZrO3 catalyst featuring a perovskite phase supported on ZrO2, prepared via citrate complexation and impregnation methods. In this approach, a perovskite-type oxide (PTO) of CaZrO3 forms through a solid reaction on the surface of ZrO2 with impregnated CaO. The formation of CaZrO3 on Ni/ZrO2 restrains the ZrO2 support aggregation and reduces the particle size of Ni nanoparticles (NPs), thereby enhancing the activity for CO2 methanation. The interaction between Ni-CaZrO3, and ZrO2 effectively confines the Ni NPs and CaZrO3, enhancing the sintering resistance of Ni-CaZrO3. This leads to excellent stability of the resulting catalyst for CO2 methanation. The Ni-CaZrO3/ZrO2 catalyst achieves 85% CO2 conversion and maintains 100% methane selectivity at 300 degrees C, demonstrating the prolonged stability over 100 h at 550 degrees C. Notably, the loading of CaZrO3 in a perovskite phase on ZrO2 via solid surface reaction represents an interesting and valuable route, which could be extended to loading other PTOs for industrial applications.