Tungsten single atoms incorporated in cobalt spinel oxide for highly efficient electrocatalytic oxygen evolution in acid

Abstract

Developing highly efficient and stable electrocatalysts with earth-abundant metals for oxygen evolution reaction (OER) in a proton exchange membrane water electrolyzer (PEMWE) is a crucial step toward lowering the cost of green hydrogen production. Here, we reveal that the incorporating of individual tungsten (W) atoms into the spinel lattice of Co₃O₄ (W–Co₃O₄) can present remarkable OER activity and stability as indicated by the small overpotential of 251 mV at 10 mA cm⁻² and the slow degradation during the long-term OER in acid electrolyte. Experiments coupled with theoretical calculations reveal significantly that the doped single W atoms possess higher OER activity than Co atoms in acid, as well as the vital role of W atoms in the stability enhancement of surface Co and O atoms during the OER process. Furthermore, the PEMWE with such a noble metal-free catalyst as an anode presents remarkable durability (240 hours) at an industrial-grade current density of 1 A cm⁻². The results obtained here represent an important step forward to the development of high-performance water electrolyzers with cheap metals.