Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (12): 2872-2880.doi: 10.3866/PKU.WHXB20112872

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Highly Active Au/α-MnO2 Catalysts for the Low-Temperature Oxidation of Carbon Monoxide and Benzene

YE Qing, HUO Fei-Fei, YAN Li-Na, WANG Juan, CHENG Shui-Yuan, KANG Tian-Fang   

  1. College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, P. P. China
  • Received:2011-06-13 Revised:2011-09-13 Published:2011-11-25
  • Contact: YE Qing
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20777005), Natural Science Foundation of Beijing, China (8082008) and Beijing Municipal Foundation for Excellent Person of Ability, China (20071D0501500210).

Abstract: α-MnO2-supported gold catalysts (xAu/α-MnO2, x=0-7 (corresponding to the Au loading (mass fraction) of 0-7%) were prepared by a deposition- precipitation method using urea as a precipitation agent and characterized by different techniques such as X-ray diffraction (XRD), N2 adsorption-desorption measurements, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and H2 temperature-programmed reduction (TPR). The catalytic activities of the materials were evaluated for the oxidation of CO and benzene. The Au particle size was found to be related to the Au loading of the xAu/ α-MnO2 samples and increased with Au loading. XPS results showed that the mole ratios of O2-/(O22- or O-), Mn4+/Mn3+ and Au3+/Au0 increased upon the addition of Au. The loading of gold over α-MnO2 significantly modified the catalytic activities. The catalytic performance of xAu/α-MnO2 strongly depended on the Au loading, and 3Au/α-MnO2 gained the best activity at T90=80 °C and T90=20 °C for the catalytic oxidation of CO and benzene, respectively. The excellent performance of 3Au/α-MnO2 is associated with highly dispersed Au, good low-temperature reducibility, and a synergism at the interface between theAu and MnO2 nanodomains.

Key words: &, alpha, -MnO2 supported gold catalyst, Low-temperature reducibility, Synergistic action, Carbon monoxide oxidation, Benzene combustion