Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (02): 437-444.doi: 10.3866/PKU.WHXB201112082

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Enhanced MnO2 Nanorods to CO and Volatile Organic Compounds Oxidative Activity by Platinum Nanoparticles

WU Xiao-Qin1,2, ZONG Rui-Long1, ZHU Yong-Fa1   

  1. 1. Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China;
    2. College of Environmental and Chemical Engineering, Nanchang Hang Kong University, Nanchang 330063, P. R .China
  • Received:2011-09-29 Revised:2011-12-01 Published:2012-01-11
  • Contact: WU Xiao-Qin, ZHU Yong-Fa;
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20925725), National Key Basic Research Program of China (973) (2007CB613303), and Jiangxi Provincial Department of Education Technology Project, China (GJJ11507).

Abstract: Pure-phase α-MnO2 and δ-MnO2 nanorods were synthesized through an easy solution-based hydrothermal method. Platinum nanoparticles supported by the obtained MnO2 nanorods were prepared by the colloid deposition process. The microstructure and adsorption activity of the obtained catalysts were researched by different techniques such as transmission electron microscopy (TEM), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption-desorption measurements, and H2 temperature-programmed reduction (H2-TPR). The cataluminescence (CTL) properties of CO and volatile organic compounds (VOCs), such as benzene and toluene, on the resultant catalysts were explored. The results showed that the platinum nanoparticles were well distributed in α-MnO2 and δ-MnO2. In addition, the Pt load process does not affect the crystal phase structure of the α-MnO2 nanorods, but can generate structural changes in the δ-MnO2 nanorods. The phase transformation did not the result of the reaction between the δ-MnO2 nanorods and Pt as shown in the XPS study. The α-MnO2 and δ-MnO2 nanorods showed a high catalytic oxidative activity toward CO, benzene, and toluene, and δ-MnO2 showed a higher activity than the α-MnO2 phase. Although, the Pt load led to a decrease in the surface area of the MnO2 nanorods which was confirmed by the N2 adsorption-desorption measurements, but the H2-TPR results showed that the interaction between Pt and MnO2 was intense, which significantly enhanced its catalytic activity. The Pt/δ-MnO2 nanorods exhibited a higher activity than Pt/α-MnO2. CTL research showed that the activities of the four catalysts increased in the order of α-MnO2≤ δ-MnO2 < Pt/α-MnO2 < Pt/δ-MnO2, and the H2-TPR results were consistent. Pt loading significantly enhanced the catalytic oxidative activity of α-MnO2 and δ-MnO2 nanorods to CO, benzene, and toluene.

Key words: Catalytic activity, MnO2 nanorod, Pt nanoparticle, Cataluminescence, CO, Benzene, Toluene


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