Hydrogenated TiO2 supported Ru for selective methanation of CO in practical conditions

Selective methanation of CO (SMET) is promising for deep removal of low-concentration CO in excess H2. However, the development of suitable catalysts applied in practical conditions remains a great challenge. Here we report a general strategy to develop highly efficient SMET catalysts by using hydrogenated TiO2 (H-TiO2) as support. The H-TiO2 supported Ru catalysts can remove CO to below 10 ppm with greater than 50 % selectivity in a wide temperature range of 200−265 °C, with a good long-term stability. Detailed characterizations including operando spectroscopy and in-situ XPS combined with DFT calculation revealed that the lowered Ru valance on H-TiO2 strengthens CO adsorption on both metal surface and metal-support interface which improved CO activation and inhibited CO2 hydrogenation, respectively, leading to enhancement of both activity and selectivity.