Decorating Single‐Atomic Mn Sites with FeMn Clusters to Boost Oxygen Reduction Reaction

The regulation of electron distribution of single‐atomic metal sites by atomic clusters is an effective strategy to boost their intrinsic activity of oxygen reduction reaction (ORR). Herein we report the construction of single‐atomic Mn sites decorated with atomic clusters by an innovative combination of post‐adsorption and secondary pyrolysis. The X‐ray absorption spectroscopy confirms the formation of Mn sites via Mn‐N4 coordination bonding to FeMn atomic clusters (FeMnac/Mn‐N4C), which has been demonstrated theoretically to be conducive to the adsorption of molecular O2 and the break of O−O bond during the ORR process. Benefiting from the structural features above, the FeMnac/Mn‐N4C catalyst exhibits excellent ORR activity with half‐wave potential of 0.79 V in 0.5 M H2SO4 and 0.90 V in 0.1 M KOH as well as preeminent Zn‐air battery performance. Such synthetic strategy may open up a route to construct highly active catalysts with tunable atomic structures for diverse applications. Coexisting single‐atomic Mn and FeMn atomic clusters sites have been fabricated by the innovative combination of post‐adsorption and secondary pyrolysis approach. This material has been demonstrated theoretically to be conducive to the adsorption of molecular O2 and the cleavage of O−O bond during the oxygen reduction reaction (ORR) process, thus improving the intrinsic ORR activity and selectivity.