Peculiarities of the Pt(Cu)/C catalyst formation by galvanic displacement of copper in H2PtCl4 solutions

Abstract

Specific features of the formation of a Pt(Cu) catalyst by the galvanic displacement of electroplated copper (carbon support) in a PtCl 4 2− solution are considered. The composition, the structure, and electrochemical properties of Pt(Cu) deposits in different stages of displacement are studied by a complex of methods (SEM, TEM, XPS, voltammetry, etc.). The gradual formation of a stable “core(Pt, Cu)-shell(Pt)” structure with the average atomic ratio Pt : Cu ≈ 3 : 1 is observed. The results for PtCl 4 2− are compared with the analogous results for PtCl 6 2− published earlier. Particularly, the reasons for the differences in the steady state potentials established on the Pt(Cu)st/C electrode in the presence of PtCl 4 2− and PtCl 6 2− are discussed.