Facile hydrothermal procedure to synthesize sheet-on-sheet reduced graphene oxide (RGO)/CuxOCeO2 nanocomposites for preferential oxidation of carbon monoxide

Abstract The sheet-on-sheet reduced graphene oxide (RGO)/Cu x O CeO 2 catalysts were synthesized by a facile hydrothermal procedure and systematically characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy and N 2 adsorption–desorption techniques. It is found that there is a large amount of reduced copper species in the RGO/Cu x O CeO 2 catalysts, and the addition of RGO was beneficial for the dispersion of particles and the improvement of textural properties. The spherical nanoparticles of copper species can be served as spacers to prevent the stacking of RGO. Copper and cerium species are homogenously distributed on the surface of RGO sheets. The introduction of RGO improves the formation of high Ce 3+ concentration and oxygen vacancies. Therefore, the RGO/Cu x O CeO 2 catalysts show higher catalytic activity than the CuO CeO 2 catalyst at low temperature (below 135 °C). Moreover, good resistance to H 2 O and CO 2 of the RGO/Cu x O CeO 2 may be from for the formation of hydroxyl groups by dissociative adsorption of H 2 O on the surface of RGO, which can improve the WGS reaction and the decomposition of carbonates.