Platinum–copper nanowire networks with enhanced CO tolerance toward methanol oxidation electrocatalysis†

Abstract

Developing platinum-based electrocatalysts with high CO tolerance for the methanol oxidation reaction (MOR) is crucial for the practical application of direct methanol fuel cells (DMFCs). Herein, we employed a straightforward one-step method to synthesize Pt_xCu_y network nanowires (NWNs), which exhibit the advantages of structural stability and bimetallic ensembles. The synergistic effect of compressive strain and the ligand effect, induced by Cu incorporation, can effectively lower the d-band center of Pt, thereby weakening the adsorption strength of CO on the catalyst surface. The optimized Pt₄₂Cu₅₈ NWNs deliver a peak mass activity of 1.33 A mg_Pt⁻¹ and a specific activity of 4.43 mA cm⁻² for the MOR, which are 3.03 and 4.03 times higher than those of commercial Pt/C, respectively. The CO stripping and in situ Fourier transform infrared spectroscopy results indicate their high anti-CO poisoning ability and methanol activation capacity. Moreover, the Pt₄₂Cu₅₈ NWNs also exhibit an excellent stability with high current densities observed after 3600 s of operation due to the enhanced CO tolerance and the stable three-dimensional (3D) network structure. This work provides a feasible strategy to suppress CO poisoning during the MOR and obtain highly efficient anode catalysts with enhanced durability in the DMFC field.