Strong metal-support interaction engineering in Ru/TiO2 mesostructures: Achieving ultra-deep CO removal below 1 ppm

Carbon monoxide selective methanation (CO-SMET) holds promise for removing low-concentration CO in the hydrocarbon reforming for hydrogen (H 2 ) production process and is a deep CO removal technology suitable for low-temperature fuel cells. However, developing highly efficient CO-SMET catalysts remains a significant challenge. Herein, we report a supported catalyst (Ru 1.0 (Cl)/TiO 2 ) with highly dispersed ruthenium (Ru) metal on a high-specific-surface-area mesoporous titanium dioxide (TiO 2 ) catalyst. This catalyst exhibits excellent performance in CO-SMET. It can reduce the CO concentration to below 10 ppm in a wide temperature range of 190–300 °C, and the outlet CO concentration can reach an ultra-low level of 0.2 ppm in the optimal temperature zone (210–220 °C). Through XPS and in situ DRIFTS characterizations, the crucial role of Ru–Cl species at the metal-support interface is revealed. The presence of chlorine atoms leads to electron enrichment in the Ru metal, enhancing its adsorption and activation of CO.