Synthesis of Non-Noble Nitrogen-Containing Catalysts for Cathodic Oxygen Reduction Reaction: A Critical Review

This paper provides an overview of the literature on the preparation aspect of nitrogen-containing electrocatalysts for oxygen reduction reaction at the cathode side of fuel cells and metal-air batteries, in particular focusing on the selection of nitrogen precursors and the exploration of synthesis methods. At present, some remarkable progress has been made in catalyst preparation techniques, but the practicalities of these catalysts have not reached the level of Pt-based catalysts. Thus, it is proposed that both new nitrogen precursors from nature and innovative preparation methods are needed for the discovery of new catalysts and for the optimization of catalyst performance.