Site-selectively Pt-decorated PdPt bimetallic nanosheets characterized by electrocatalytic property for methanol oxidation

Abstract

In this work, a facile synthetic method for site-selectively Pt-decorated PdPt bimetallic nanosheets (S-Pt-PdPtBN) has been described. The size, structure, and composition distribution of the synthesized S-Pt-PdPtBN were determined by transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The electrocatalytic activity of these bimetallic nanosheets was examined for the oxidation of methanol in an acidic solution. The electrochemically active surface area (ECSA) of S-Pt-PdPtBN was 0.842 cm(2). This value is slightly lower than the ECSA (1.012 cm(2)) of the commercial Pt/C (Alpha, Pt 10%) electrode. Interestingly, even though the ECSA of the S-Pt-PdPtBN/C was smaller than that of the commercial Pt/C, the forward peak current density of the former (2.95 mA cm(-2)) was ca. 1.5 times higher than that of the latter (2.05 mA cm(-2)). Moreover, the current density of the S-Pt-PdPtBN/C catalysts was high even after 800 s of continuous electrocatalysis at 0.5 V. This current density is six times that of commercial Pt/C catalysts. Thus, the synthesized S-Pt-PdPtBN exhibited significantly enhanced electrocatalytic activity and better stability than the commercial Pt/C catalyst for methanol oxidation. (C) 2018 Elsevier B.V. All rights reserved.