Deposition of Pd–Fe nanoparticles onto carbon spheres with controllable diameters and applied for CO catalytic oxidation
In this paper, a series of Pd–Fe/carbon sphere (CS) catalysts were prepared by a co-precipitation method and applied in low-temperature CO oxidation reactions. The effect of the particle sizes of carbon spheres, calcination temperatures of catalysts, Pd loadings and H2 reduction were investigated in detail. SEM and TEM characterizations of carbon spheres that were prepared by a hydrothermal method indicated non-porous structure, and the CSs surface was covered by Pd–Fe composites after the preparation of the catalyst. The XPS characterization of the catalysts showed that there were rich active oxygen species, more FeO(OH) species and more tetravalent Pd (PdO2) species on the surface of the Pd–Fe/CSs catalyst. These factors are expected be helpful for CO oxidation. When Pd loading was 1.0 wt%, the Pd–Fe/CSs (CSs were prepared by 1.0 mol L−1 glucose solution) catalyst, which was calcined at 200 °C without H2 reduction, had the highest activity.