Uniform Pd–Pt alloy nanoparticles supported on graphite nanoplatelets with high electrocatalytic activity towards methanol oxidation

Abstract

In this paper, we present a simple and facile strategy to prepare highly uniform Pd–Pt alloy nanoparticles (NPs) with different Pt/Pd molar ratios on 1-pyrenecarboxylic acid (PCA) decorated graphite nanoplatelets (GNPs). The binary composition of these Pd–Pt/GNPs catalysts is controlled by simply adjusting the molar ratio of the Pd and Pt precursors. The obtained catalysts were characterized by ultraviolet-visible light (UV-vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometry (ICP-OES). The HRTEM measurements show that all of the metallic NPs exhibit well-defined crystalline structures. Both cyclic voltammetry (CV) and chronoamperometry (CA) demonstrate that the Pd₁Pt₃/GNPs catalyst has the highest catalytic activity towards methanol oxidation reaction (MOR) among the Pd–Pt/GNPs with different compositions studied. Moreover, the Pd₁Pt₃/GNPs catalyst markedly outperforms Pt/GNPs and the commercial Pt/C-JM catalyst in terms of both MOR activity and stability. The present method represents a simple and general approach to synthesizing bimetallic Pt-M electrocatalysts on an alternative carbon support, which is expected to find applications in fuel cells.