Specific features of the formation of Pt(Cu) catalysts by galvanic displacement with carbon nanowalls used as support

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• 作者：B.I. Podlovchenko ; V.A. Krivchenko ; Yu.M. Maksimov ; T.D. Gladysheva ; L.V. Yashina ; S.A. Evlashin ; A.A. Pilevsky
• 关键词：Carbon nanowalls (CNWs) ; Copper ; Platinum ; Galvanic displacement ; Core&ndash ; shell structure ; Electrocatalytic properties
• 刊名：Electrochimica Acta
• 出版年：2012
• 出版时间：1 August, 2012
• 年：2012
• 卷：76
• 期：Complete
• 页码：137-144
• 全文大小：1476 K

文摘

Microamounts of Cu are applied by the methods of electrodeposition (Cu_ed) and magnetron sputtering (Cu_spr) on a new carbon material, carbon nanowalls (CNW). The galvanic displacement (GD) of Cu_ed and Cu_spr in a PtCl₄^2? solution (with 0.5 M H₂SO₄ as the supporting electrolyte) produces Pt(Cu)/CNW catalysts. The possibility of using open-circuit potential transients recorded in the course of GD for monitoring the surface layer composition is considered. The stable Pt(Cu)_st samples are characterized by several methods (SEM, TEM, XPS, voltammetry, etc.). It is shown that Pt(Cu)_st has structure of the core(Pt, Cu)-shell(Pt) type with the average atomic ratio Pt:Cu ( % ) ¡« 57:43 for Cu_ed and ¡«80:20 for Cu_spr. The formation of the dense Pt shell is also confirmed by the data on the electrocatalytic activity of synthesized samples in the methanol oxidation reaction. The reasons for deviations in the properties of Pt(Cu)_st/CNW samples formed from Cu_ed and Cu_spr are discussed. The high specific surfaces of the Pt(Cu)_st/CNW catalyst obtained from Cu_ed (>40 m²/g Pt) with the simultaneous decrease in the Pt content makes this material promising for using in the platinum-catalyzed processes (particularly, in fuel cells).