Structural coordination of M-N-C catalysts toward efficient electrochemical hydrogen peroxide production

Hydrogen peroxide (H2O2), an environmentally friendly and efficient oxidant, is broadly applied in various industries. Electrocatalytic H2O2 production via two-electron oxygen reduction (2e- ORR) has attracted extensive research attention owing to its efficient, safe, and environmentally friendly features. However, the quest for highly active and selective electrocatalysts without precious metal elements persists. Metal-nitrogen-carbon (M-N-C) materials with non-precious transition metals have the advantages of low cost, abundant availability, and, more importantly, accessible control over electrocatalytic pathways via manipulating coordination environments, so they have been widely applied in the electrocatalytic synthesis of hydrogen peroxide. This review introduced the mechanisms and vital intermediate species of 2e- ORR and summarized how different metal sites and coordination environments of M-N-C affected the H2O2 selectivity.