Oxygen reduction reaction has been widely studied by many researchers,especially in the fields of new energy batteries,chemicals production,and bioelectrochemistry. In fuel cells and metal-air batteries,oxygen reduction reaction sites are provided by cell cathodes to transfer oxygen ions. While its development is severely constrained by limitations as high overpotential and slow kinetics and thus the key to improve device performance and reduce manufacturing cost is to develop cost-effective cathode catalysts. Although platinum is considered to be the most effective electrocatalyst for oxygen reduction reaction,it is still severely restricted by production and cost. Transition metal oxides,doping carbon and other materials have aroused wide attentions owing to their good catalytic activity and electrochemical stability,and extensive research is also carried out on these non-noble metal catalysts. However,compared to traditional Pt/C catalysts,they still exhibit low catalytic activity and conductivity,which cannot meet the needs of industrial applications such as new energy battery. Therefore,researchers have used doping,composite modifying and other channels to improve their electrochemical activity characteristics. This review aims to summarize the advances on electrocatalysts for oxygen reduction reaction,with a detail about modification methods and related progress of the most popular materials on current catalyst in recent three years. The oxygen reduction reaction mechanism is briefly introduced to provide a better analysis on the electrocatalytic performance of catalysts,and catalysts as well as their main application fields are discussed. Additionally,the future trend emerging in electrocatalyst systems for oxygen reduction is presented,providing a reference for their feasibility to further promote practical applications in fuel cells and metal-air batteries. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.
