Amorphous MoO x with high oxophilicity interfaced with PtMo alloy nanoparticles boosts anti-CO hydrogen electrocatalysis.

Advancing electrocatalysts for alkaline hydrogen oxidation/evolution reaction (HOR/HER) is essential for anion exchange membrane-based devices. The state-of-the-art Pt-based electrocatalysts for alkaline HOR are suffering from low intrinsic activities and severe CO poisoning due to challenge of simultaneously optimizing surface adsorptions towards different adsorbates. Herein, we overcome this challenge by tuning atomic MoO x layer with high oxophilicity onto PtMo nanoparticles with the optimized H ad , OH ad and CO ad adsorptions for boosting anti-CO poisoning hydrogen cycle electrocatalysis in alkaline media. For alkaline HOR, this catalyst exhibits a high kinetic and an exchange current density of 3.19 mA μg Pt -1 at 50 mV versus RHE and 0.83 mA cm Pt -2 , 10.3 and 3.8-fold higher than those of commercial Pt/C, respectively. For alkaline HER, it achieves an unprecedented overpotential of 37 mV at 10 mA cm -2 . Experimental and theoretical studies show that the orchestrated electronic and oxophilic regulation of PtMo/MoO x interface nanoparticles simultaneously optimize H ad and OH ad adsorption for boosting alkaline hydrogen electrocatalysis, whereas reactive oxygen from amorphous MoO x atomic layer lowers the CO oxidation reaction barrier, leading to superior anti-poisoning ability even at 100 ppm CO. This article is protected by copyright. All rights reserved.