Oxygen deficient yolk–shell structured Co3O4 microspheres as an oxygen evolution reaction electrocatalyst for anion exchange membrane water electrolyzers

Abstract

Anion exchange membrane water electrolyzers (AEMWEs) are a promising next-generation technology for producing clean hydrogen using cost-effective, non-platinum group metal (non-PGM) based electrocatalysts. Despite their potential advantages, their low energy conversion efficiency presents a significant obstacle to their commercialization. Herein, we developed an oxygen deficient yolk–shell structured Co₃O₄ as the oxygen evolution reaction electrocatalyst for AEMWEs. The yolk–shell structure provided a large surface area, and the introduction of oxygen vacancies to the yolk–shell structured Co₃O₄ modulated the electronic structure and enhanced the OER activity. The abundant voids in the yolk–shell structure facilitated mass transport and effectively reduced mass transport loss in the AEMWE, resulting in excellent performance at high current density. This work suggests that the yolk–shell structured electrocatalysts can effectively improve the performance of AEMWEs, thereby addressing the major obstacle that is currently delaying their commercialization.