Mn-N₃-O-Loaded Graphitic Carbon Aerogel for an Efficient Oxygen Reduction Reaction

Deleterious reactive oxygen species are frequently producedbysome single-atom electrocatalysts via the Fenton reaction when theycatalyze the oxygen reduction reaction (ORR). The single-atom electrocatalystsbased on Mn are generally considered to have low Fenton reactivity.Herein, an atomically dispersed Mn-N-3-O-loadedgraphitic carbon aerogel (Mn-N-C) is prepared simplyby heating a carbon aerogel and molten MnCl2 under ammoniagas. Mn-N-C exhibits approximately 0.900 V vs the reversiblehydrogen electrode half-wave potential, and only 8 mV is lost after5000 cycles, accelerating the durability test for the ORR in 0.10mol/L KOH. In a zinc-air battery, Mn-N-C exhibitscycling stability over 350 h without a significant drop and a peakpower density of 210 mW/cm(2). Based on density functionaltheory calculations, X-ray absorption spectroscopy, and high-resolutionTEM, the formation mechanism and high performance of the Mn-N-3-O sites in Mn-N-C are well demonstrated.The strategy of heating the carbon aerogel and molten salts underammonia gas might offer a universal method for metal-N-Csynthesis. Mn-N-3-O-loadedgraphitic carbonis prepared by simply heating an aerogel under ammonia gas and moltenMnCl(2) for a sustainable Zn-air battery.