Unveiling the Promoting Mechanism of H Activation on CuFeO Catalyst for Low-Temperature CO Oxidation.

The effect of H activation on the performance of CuFeO catalyst for low-temperature CO oxidation was investigated. The characterizations of XRD, XPS, H-TPR, O-TPD, and in situ DRIFTS were employed to establish the relationship between physicochemical property and catalytic activity. The results showed that the CuFeO catalyst activated with H at 100 °C displayed higher performance, which achieved 99.6% CO conversion at 175 °C. In addition, the H activation promoted the generation of Fe species, and more oxygen vacancy could be formation with higher concentration of O species, which improved the migration rate of oxygen species in the reaction process. Furthermore, the reducibility of the catalyst was enhanced significantly, which increased the low-temperature activity. Moreover, the in situ DRIFTS experiments revealed that the reaction pathway of CO oxidation followed MvK mechanism at low temperature (<175 °C), and both MvK and L-H mechanism was involved at high temperature. The Cu-CO and carbonate species were the main reactive intermediates, and the H activation increased the concentration of Cu species and accelerated the decomposition carbonate species, thus improving the catalytic performance effectively.