Size Effects of Platinum Colloid Particles on the Structure and CO Oxidation Properties of Supported Pt/Fe2O3 Catalysts

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• 作者：Nihong An ; Suying Li ; Paul N. Duchesne ; Ping Wu ; Wenlong Zhang ; Jyh-Fu Lee ; Soofin Cheng ; Peng Zhang ; Mingjun Jia ; Wenxiang Zhang
• 刊名：Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：October 17, 2013
• 年：2013
• 卷：117
• 期：41
• 页码：21254-21262
• 全文大小：509K
• 年卷期：v.117,no.41(October 17, 2013)
• ISSN：1932-7455

文摘

Three supported Pt/Fe₂O₃ catalysts were prepared by depositing platinum colloids with discrete particle sizes onto the surface of Fe(OH)₃ powders, which were then calcined at an elevated temperature. Pt nanoparticle colloids with mean diameters of 1.1, 1.9, or 2.7 nm were synthesized in order to investigate the effects of particle size on the structure and CO oxidation properties of these Pt/Fe₂O₃ catalysts. All Pt/Fe₂O₃ catalysts demonstrated activity in low-temperature CO oxidation, with the sample containing Pt nanoparticles with a mean diameter of 1.9 nm (designated Pt/Fe₂O₃-b) exhibiting relatively higher catalytic activity. Compared with the other two catalysts, Pt/Fe₂O₃-b exhibited an increased ability to activate oxygen and maintain the stability of Pt species, correlating with its higher catalytic activity. The results of various characterization techniques revealed that the mean particle size of the Pt nanoparticles could influence the chemical states of Pt species and the strength of metal鈥搒upport interactions of the Pt/Fe₂O₃ catalysts. It was observed that the metal鈥搒upport interactions in Pt/Fe₂O₃ catalysts were able to adjust the redox properties and the O₂-activation abilities of the catalysts. Finally, it is proposed that the interacting Pt and Fe species located at the Pt鈥揊eO_x interface are the primary active sites for the activation of CO and O₂, respectively.