Amorphous mixed Ir–Mn oxide catalysts for the oxygen evolution reaction in PEM water electrolysis for H2 production

Abstract

Proton exchange membrane (PEM) water electrolysis is a kind of green and sustainable hydrogen production technology. However, it is limited by sluggish kinetics of anodic oxygen evolution reaction (OER), and it is necessary to develop efficient, stable and economical catalysts. In this manuscript, amorphous mixed Ir–Mn oxide catalysts (IrMnOx) with different Mn contents are synthesized by simple low-temperature calcination. IrMnOx catalysts have poor crystallinity and abundant surface hydroxyl defects, which helps improve catalytic activity and electrochemical stability for acidic OER. Compared with commercial rutile IrO2, they show lower overpotential and higher current density. Among the prepared catalysts, Ir0·6Mn0.4Ox and Ir0·7Mn0.3Ox perform best, and overpotentials are only 212 mV at the current density of 10 mA/cm2 and 263 mV at 100 mA/cm2, and there is no obvious activity decay after the 8-h stability experiment. IrMnOx catalysts reported provide hope for high-efficiency oxygen evolution reaction in PEM water electrolysis.