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.