Charge Transfer at the Interface of Iridium and Atomically Dispersed Mn–O Clusters Induced Full-Potential Hydrogen Oxidation

Abstract

Hydrogen has long been an important energy source for sustainable development, and platinum group metals (PGMs) are the prominent anode catalysts for anion exchange membrane fuel cells (AEMFCs). However, among the PGM catalysts used in alkaline hydrogen oxidation reaction (HOR) for the AEMFC anode, the activity of iridium decreases sharply when the reaction potential exceeds 0.2 V vs reversible hydrogen electrode (RHE) due to the reduction of hydrogen adsorption (H_ad), which is caused by the overadsorption of OH. Herein, we prepared Ir nanoparticles with atomically dispersed Mn–O clusters on their surface (Ir/Mn_0.40OC), the difference in the work function drives the charge transfer from Mn–O clusters to Ir at full HOR potential (∼0–1.2 V vs RHE), which could upshift its d-band center to enhance H_ad. This strategy realized HOR at full potential and the 5 h durability test only lost about 10.9% current density at 0.71 V vs RHE. Moreover, this catalyst could be used in the AEMFC anode and the mass-normalized activity of the anode reaches 8.26 W mg_Ir^–1.