Sub-Monolayer YOx/MoOx on Ultrathin Pt Nanowires Boosts Alcohol Oxidation Electrocatalysis

A crucial issue restricting the application of direct alcohol fuel cells (DAFCs) is the low activity of Pt-based electrocatalysts for alcohol oxidation reaction caused by the reaction intermediate (CO*) poisoning. Herein, a new strategy is demonstrated for making a class of sub-monolayer YOx/MoOx-surface co-decorated ultrathin platinum nanowires (YOx/MoOx-Pt NWs) to effectively eliminate the CO poisoning for enhancing methanol oxidation electrocatalysis. By adjusting the amounts of YOx and MoOx decorated on the surface of ultrathin Pt NWs, the optimized 22% YOx/MoOx-Pt NWs achieve a high specific activity of 3.35 mA cm(-2) and a mass activity of 2.10 A mg(Pt)(-1), as well as the enhanced stability. In situ Fourier transform infrared (FTIR) spectroscopy and CO stripping studies confirm the contribution of YOx and MoOx to anti-CO poisoning ability of the NWs. Density functional theory (DFT) calculations further reveal that the surface Y and Mo atoms with oxidation states allow COOH* to bind the surface through both the carbon and oxygen atoms, which can lower the free energy barriers for the oxidation of CO* into COOH*. The optimal NWs also show the superior activities toward the electro-oxidation of ethanol, ethylene glycol, and glycerol.

Automated summary

This study demonstrates a new strategy to fabricate platinum nanowires that effectively eliminate CO poisoning, leading to enhanced methanol oxidation electrocatalysis. The optimized nanowires show high specific and mass activity, as well as improved stability, and also exhibit superior activities towards the electro-oxidation of other alcohols.