Preparation of Pt electrocatalysts by galvanic displacement

Abstract

Pt-based electrocatalysts were prepared by spontaneous deposition (galvanic displacement) of Pt on carbon-supported Ni, Sn, and NiSn electrocatalysts. The spontaneous deposition of Pt was performed by stirring of an aqueous solution of H2PtCl6·6H2O in the presence of Ni/C, Sn/C, and NiSn/C for 1 h at room temperature and open atmosphere. The obtained materials were characterized Energy-dispersive X-ray Analysis (EDX), x-ray diffraction (XRD), transmission electron microscopy (TEM), and cyclic voltammetry, and were tested for ethanol electro-oxidation using chronoamperometry. X-ray diffractograms of Ni/C and Sn/C showed that a Ni(fcc) phase and metallic Sn were formed, respectively. For NiSn/C, the presence of metallic Sn and NiSn phases was observed. After the spontaneous deposition of Pt, the x-ray diffractograms of the obtained materials did not show the presence of the crystalline phases of Pt; however, EDX analysis showed the presence of Pt in these materials. The materials obtained after spontaneous deposition of Pt showed a superior activity for ethanol electro-oxidation compared with the starting materials.