Enhanced Electrocatalytic Performance of Processed, Ultrathin, Supported Pd鈥揚t Core鈥揝hell Nanowire Catalysts for the Oxygen Reduction Reaction

详细信息    查看全文

• 作者：Christopher Koenigsmann ; Alexander C. Santulli ; Kuanping Gong ; Miomir B. Vukmirovic ; Wei-ping Zhou ; Eli Sutter ; Stanislaus S. Wong ; Radoslav R. Adzic
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：June 29, 2011
• 年：2011
• 卷：133
• 期：25
• 页码：9783-9795
• 全文大小：1210K
• 年卷期：v.133,no.25(June 29, 2011)
• ISSN：1520-5126

文摘

We report on the synthesis, characterization, and electrochemical performance of novel, ultrathin Pt monolayer shell鈥揚d nanowire core catalysts. Initially, ultrathin Pd nanowires with diameters of 2.0 卤 0.5 nm were generated, and a method has been developed to achieve highly uniform distributions of these catalysts onto the Vulcan XC-72 carbon support. As-prepared wires are activated by the use of two distinctive treatment protocols followed by selective CO adsorption in order to selectively remove undesirable organic residues. Subsequently, the desired nanowire core鈥揚t monolayer shell motif was reliably achieved by Cu underpotential deposition followed by galvanic displacement of the Cu adatoms. The surface area and mass activity of the acid and ozone-treated nanowires were assessed, and the ozone-treated nanowires were found to maintain outstanding area and mass specific activities of 0.77 mA/cm² and 1.83 A/mg_Pt, respectively, which were significantly enhanced as compared with conventional commercial Pt nanoparticles, core鈥搒hell nanoparticles, and acid-treated nanowires. The ozone-treated nanowires also maintained excellent electrochemical durability under accelerated half-cell testing, and it was found that the area-specific activity increased by 1.5 fold after a simulated catalyst lifetime.