Hydrogen co-reduction synthesis of PdPtNi alloy nanoparticles on carbon nanotubes as enhanced catalyst for formic acid electrooxidation

Abstract

A novel electrocatalyst of PdPtNi ternary alloy nanoparticles supported on multi-walled carbon nanotubes (MWCNTs) for formic acid oxidation (FAO) reaction is synthesized by a simple hydrogen co-reduction process. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy and X-ray photoelectron spectroscopy (XPS). It is found that highly dispersed PdPtNi alloy nanoparticles of ca. 2.56 nm are homogeneously deposited on the MWCNT surface, and the alloying with Pt and Ni alters the electronic structure of Pd atoms with the downshift of Pd d-band center. Studies of cyclic voltammetry and chronoamperometry indicate that the electrocatalytic activity and durability of the PdPtNi/MWCNT for FAO are significantly enhanced as compared with the PdPt/MWCNT and commercial Pd/C catalysts. This study implies that the prepared PdPtNi/MWCNT composite is a promising anode electrocatalyst of direct formic acid fuel cells.