CePO4 (in particular, monoclinic CePO4) has been rarely used to make supported catalysts. Herein, monoclinic CePO4 nanoparticles were prepared by calcining hexagonal CePO4 nanorods (prepared by precipitation) in air at 900 degrees C. Monoclinic CePO4 nanowires were prepared by calcining hexagonal CePO4 nanowires (prepared by hydrothermal synthesis at 150 degrees C) in air at 900 degrees C. Both monoclinic CePO4 materials were used to support Rh2O3 by impregnation using Rh(NO3)(3) as a precursor (followed by calcination). The catalytic performance of Rh2O3/monoclinic CePO4 composite materials in N2O decomposition and CO oxidation was investigated. It was found that Rh2O3 supported on monoclinic CePO4 nanowires was much more active than Rh2O3 supported on monoclinic CePO4 nanoparticles. The stability of catalysts as a function of reaction time on stream was studied in both reactions. The influence of co-fed CO2, O-2, and H2O on the catalytic activity in N2O decomposition was also studied. These catalysts were characterized by employing N-2 adsorption-desorption, ICP-OES, XRD, TEM, XPS, H-2-TPR, O-2-TPD, and CO2-TPD. The correlation between physicochemical properties and catalytic properties was discussed. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.