Promotion effect of metal oxides on inverse CeO2/CuO catalysts for preferential oxidation of CO

• MOx–CeO2/CuO catalysts were synthesized by hydrothermal method.
• Addition of Mn is the most effective for improving low–temperature activity.
• MnO2 improves the dispersion of CeO2 and the textural property of CeO2/CuO catalyst.
• The presence of MnO2 is favorable for preventing the reduction of CuO.
• MnO2 enhances the interaction between CeO2 and CuO.

The MOx–CeO2/CuO (M = Co, Mn, Sn and Zn) catalysts were synthesized by the hydrothermal method and characterized by XRD, BET, SEM, H2-TPR and HRTEM techniques. It is found that the MnO2–CeO2/CuO catalyst exhibits the best activity from 75 °C to 115 °C, suggesting that the addition of Mn is the most effective for improving low-temperature activity. The reasons are that MnO2 improves the dispersion of CeO2 and the textural property of CeO2/CuO catalyst. Moreover, the presence of MnO2 is favorable for preventing the reduction of CuO, and MnO2 also enhances the interaction between CeO2 and CuO.

TEM and HRTEM images of the MnO2–CeO2/CuO catalystThe filamentous-like CeO2 is composed of about 5 nm CeO2 particles, and they are dispersed on the surface of bulk CuO. Moreover, a small amount of particle-like CeO2 is also located on the surface of bulk CuO. The CeO2 with two-kind morphologies has an interaction with the CuO particles on the contact interface.Figure optionsDownload as PowerPoint slide