Pt or Pd-doped Au/SnO 2 Catalysts: High Activity for Low-temperature CO Oxidation
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Pt or Pd-doped Au/SnO2 Catalysts: High Activity for Low-temperature CO Oxidation Qing Ye • Juan Wang • Jiansheng Zhao • Lina Yan Shuiyuan Cheng • Tianfang Kang • Hongxing Dai
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Received: 31 January 2010 / Accepted: 22 April 2010 / Published online: 15 May 2010 Ó Springer Science+Business Media, LLC 2010
Abstract yAu/SnO2 (y = 1–5 wt%) and 1 wt% Pt- or Pd-doped 3Au/SnO2 catalysts were prepared by the co-precipitation method. It is observed that the 3Au/SnO2 catalyst showed the best performance (T100% = 166 °C). The pretreatment of 3Au/SnO2 in CO obviously decreased the catalytic activity due to the reduction of oxidized gold species to metallic Au0. Pd- or Pt-doping to 3Au/SnO2 brought about a significant enhancement in performance, with the T100% value being 74 and 93 °C, respectively. It is concluded that the oxidized gold species were more active than metallic Au0 and the remarkable improvement in catalytic activity due to Pd or Pt doping was associated with the presence of strong interaction of Pd or Pt with Au. Keywords CO low-temperature oxidation Tin oxide supported gold catalyst Co-precipitation method Binary noble metal catalyst
Electronic supplementary material The online version of this article (doi:10.1007/s10562-010-0360-x) contains supplementary material, which is available to authorized users. Q. Ye (&) J. Wang J. Zhao L. Yan S. Cheng T. Kang Department of Environmental Science, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, People’s Republic of China e-mail: [email protected] H. Dai (&) Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, People’s Republic of China e-mail: [email protected]
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1 Introduction CO is harmful to the environment. It is usually generated due to the incomplete combustion of carbon-containing substance. Catalytic oxidation of carbon monoxide at low temperatures has found applications in air purification, recombination of CO and O2 produced in closed cycle CO2 lasers [1], and CO sensors [2]. In recent years, CO oxidation has been intensively studied due to its potential applications in fuel cell systems to purify the feed hydrogen [3, 4]. Since Haruta et al. [5] reported an exceptionally high activity of gold-based catalysts for low-temperature CO oxidation in 1987, many researchers have investigated the catalysis of nanosized gold for CO oxidation. The catalytic performance of gold catalysts is sensitive to the particle size, support nature, and preparation procedure [6, 7]. When gold was highly dispersed on semiconductor metal oxides (e.g., TiO2, a-Fe2O3, and Co3O4), the obtained catalysts showed high activity for the oxidation of CO at low temperatures [8]. Tin dioxide is an n-type semiconductor with a wide bandgap. In the past decades, SnO2 has attracted much attention for its various applications in catalysis, gas sensing, rechargeable Li battery, and op
