Improved stability of Y₂O₃ supported Ni catalysts for CO₂ methanation by precursor-determined metal-support interaction

Y₂O₃ supported Ni catalysts were prepared from different Y precursors. The catalysts synthesized via Y₄O(OH)₉(NO₃) and YO(NO₃) as precursors exhibit superior activity in CO₂ methanation reaction compared to the catalysts prepared by direct impregnation of Y₂O₃. YO(NO₃) acts as a unique matrix to afford anchoring sites to interact with Ni²⁺ ions, leading to a moderate interaction between Ni metal and Y₂O₃ support, which translates into excellent catalytic activity and stability towards CO poisoning. In situ DRIFTS spectra confirm the reaction mechanism of Ni/Y₂O₃ catalyzed CO₂ methanation with carbonates and formates as the key intermediates. The apparent difference in the rate of transformation of formates into methane determines catalytic activity of these Ni/Y₂O₃ catalysts. This work provides an effective strategy to achieve CO₂ activation and resistance to CO poisoning through careful selection of precursor for the support, which allows to control the strength of metal-support interaction.