The influence of CePO₄ nanorods on the CO oxidation activity of Au/GdPO₄-rods

In this work, Au/GdPO₄-rods were found to be good catalysts for CO oxidation with a low content of Au. The dopant of CePO₄ could influence the activity of Au/GdPO₄ due to the synergistic effect. GdPO₄ and CePO₄ nanorods were obtained by a hydrothermal process and the Au/GdPO₄-rod and Au/Ce-GdPO₄-rod catalysts were prepared by deposition-precipitation synthesis. The samples were extensively characterized by transmission electron microscopy (TEM), inductively coupled plasma (ICP), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), temperature programmed desorption (O₂-TPD, CO-TPD, and CO₂-TPD) and N₂ adsorption-desorption. The results showed that Au/GdPO₄ with a low Au content possessed good activity for CO oxidation. When the content of Ce is 25 at%, 0.5% Au/Ce-GdPO₄-rods can convert CO completely at 65 °C, and the catalyst showed better high-temperature resistance than 0.5% Au/GdPO₄-rods. 0.5% Au/Ce-GdPO₄-rods also showed good stability at reaction temperatures of 55 and 65 °C with CO conversions of 90% and 100% after continuous operation for 12 h. They also showed no deactivation after 50 h at a relative high reaction temperature of 200 °C.