Bimetallic nanoparticles of PtM (M = Au, Cu, Ni) supported on iron oxide: Radiolytic synthesis and CO oxidation catalysis

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• 作者：Takao A. Yamamoto ; Takashi Nakagawa ; Satoshi Seino ; Hiroaki Nitani
• 关键词：CO oxidation ; Bimetallic catalyst ; Radiolytic synthesis ; Platinum ; Copper
• 刊名：Applied Catalysis A: General
• 出版年：2010
• 出版时间：20 October 2010
• 年：2010
• 卷：387
• 期：1-2
• 页码：195-202
• 全文大小：1169 K

文摘

Bimetallic composite nanoparticles of PtM (M = Au, Cu or Ni) supported on γ-Fe₂O₃ were synthesized by a radiolytic method employing a 4.8-MeV electron beam to reduce aqueous ions. These composite particles were obtained at room temperature just by irradiating glass vials containing source materials in an aqueous system without using any surfactant, organic solvent and stabilizer. The irradiation, taking several seconds, formed metallic nanograins of 3 nm in diameter stabilized on the support of γ-Fe₂O₃ particle of 13 nm in diameter. XRD patterns of PtAu and PtCu samples showed clear peak shifts indicating occurrence of random alloy phase. X-ray absorption fine structure analysis for the PtCu and PtNi samples indicated significant Pt–M coordination. Catalytic activity of CO oxidation of the samples was evaluated by measuring residual CO contents in air in contact with the sample material with a gas-chromatograph. All the PtM systems exhibited activities higher than those of monolithic Pt on γ-Fe₂O₃. The correlation between the atomic structures and the catalytic activities indicated that the random alloy structure enhances the activity.