Influence of preparation method on the catalytic activities of CuO/Ce0.67Zr0.33O2 catalysts in CO + O2 reaction

Ce0.67Zr0.33O2 solid solutions synthesized by traditional co-precipitation method (hereafter donated as CZ-CP) and hydrothermal method (hereafter donated as CZ-HT) were used as supports for preparing a series of CuO/Ce0.67Zr0.33O2 catalysts. High resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction (TPR), CO adsorption in situ Fourier transform infrared spectroscopy (CO in situ FT-IR) and the activity of CO oxidation model reaction at low temperature (<200 °C) were used to approach the properties of the catalysts. The results showed that the Ce0.67Zr0.33O2 prepared by hydrothermal method facilitate the formation and stabilization of Cu+ on the surface of support and thus the activity for CO + O2 reaction was improved. A tentative model was suggested that the difference in the preferentially exposed plane of CZ-CP and CZ-HT leads to the great difference in dispersion, reduction and reaction activity of the dispersed copper oxide species on these two supports.