Recent Advances in Non-Noble Bifunctional Oxygen Electrocatalysts toward Large-Scale Production

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial reactions in energy conversion and storage systems including fuel cells, metal-air batteries, and electrolyzers. Developing low-cost, high-efficiency, and durable non-noble bifunctional oxygen electrocatalysts is the key to the commercialization of these devices. Here, based on an in-depth understanding of ORR/OER reaction mechanisms, recent advances in the development of non-noble electrocatalysts for ORR/OER are reviewed. In particular, rational design for enhancing the activity and stability and scalable synthesis toward the large-scale production of bifunctional electrocatalysts are highlighted. Prospects and future challenges in the field of oxygen electrocatalysis are presented.