Au Doping PtNi Nanodendrites for Enhanced Electrocatalytic Methanol Oxidation Reaction

Abstract

To boost the electrocatalytic methanol oxidation reaction (MOR) of Platinum (Pt), making binary PtM (M = transition metals, for example, Fe, Cu, and Ni) with specific morphology is known as a promising method. Although great progress has been made in the synthesis of shaped PtM catalysts toward MOR, enhancing the catalytic performance of the PtM to enable it to be commercialized is still a hotspot. In this work, the Au-doped PtNi dendritic nanoparticles (Au-PtNi DNPs) were obtained by doping a small amount of gold (Au) into initially prepared PtNi DNPs, greatly improving their MOR catalytic activity and durability. The energy-dispersive X-ray spectroscopy mapping (EDXS) indicates that the surface of DNPs is mainly composed of Au dopant and PtNi, while the core is mainly Pt, indicating the formation of Au-doped PtNi/Pt core-shell-like DNP structures. The electrocatalytic performance of the prepared Au-PtNi DNPs with different compositions for the MOR was evaluated using cyclic voltammetry, chronoamperometry, and CO-stripping tests. The experimental findings indicate that the Au-PtNi DNPs showed better MOR performance in comparison with PtNi DNPs and commercial Pt catalysts. Among all the catalysts, 6% Au-PtNi DNPs showed 4.3 times improved mass catalytic activity for the MOR in comparison with commercial Pt catalysts. In addition, all the prepared Au-PtNi DNPs display a remarkable CO tolerance compared to that of PtNi DNPs and commercial Pt catalysts. The dendritic structure of Au-PtNi DNPs can effectively enhance catalytic performance, combined with the electronic effect of Au, Pt, and Ni.

Keywords

• Au dopant
• nanodendrite
• AuPtNi shell
• methanol oxidation reaction