Low Temperature Oxidation of Carbon Monoxide over Mesoporous Au-Fe2O3Catalysts

Abstract

Low temperature active and stable mesoporous Au (0.1, 0.2, 0.5, and 1.0 wt.%) supportedα-Fe2O3catalysts were prepared via deposition-precipitation method. The H2-pretreated catalyst with 0.5 wt.% Au loading offered CO conversion of 100% at 323 K and showed continual activity for at least 120 h. X-ray diffraction and transmission electron microscopy analysis indicate that Au species were highly dispersed as nanoparticles (20–40 nm) on the surface ofα-Fe2O3support even after thermal treatment at 773 K. The N2-physisorption measurements show that the synthesizedα-Fe2O3support and Au-Fe2O3nanocomposites possessed mesopores with high specific surface area of about 158 m2 g−1. X-ray photoelectron spectroscopy and H2-TPR results reveal that the Au species exist in metallic and partially oxidized state due to strong interaction with the support. Effective Au-Fe2O3interaction resulted in a high activity for Au nanoparticles, locally generated by the thermal treatment at 773 K in air.