Boosting oxygen evolution via lattice oxygen activation in high-entropy perovskite oxides

Abstract

The development of high-performance oxygen evolution reaction (OER) catalysts is essential for advancing various electrochemical energy technologies. In this work, we introduce a novel high-entropy perovskite oxide, (LaPrSr)(FeCoNi)O₃ (LPSFCNO), as an efficient OER electrocatalyst. Notably, we demonstrate that the OER pathway in this electrocatalyst can be strategically shifted from the conventional adsorbate evolution mechanism (AEM) to the more favorable lattice oxygen-mediated mechanism (LOM) by activating lattice oxygen, resulting in significantly enhanced intrinsic activity. This shift is achieved by adjusting the metal composition at the A and B sites of the perovskite structure. Experimental evidence confirms that the incorporation of different multivalent metals at each side effectively promotes the formation of oxygen ligand holes, facilitates charge transfer from oxygen sites, and enhances the generation and migration of oxygen vacancies. Consequently, lattice oxygen is more actively involved in surface reactions, leading to superior OER performance. Building on the exceptional qualities of these oxygen catalysts, high-performance zinc–air batteries were successfully assembled and tested, demonstrating outstanding efficiency and stability. These findings provide valuable insights into the role of oxygen activity in OER catalysis and suggest a promising strategy for designing highly active electrocatalysts.