A Dual‐Atom La ₂ Catalyst for the Oxygen Reduction Reaction

Abstract

Abstract Rare earth lanthanum element has a large atomic radius, multi‐shell orbital electrons, and Fenton‐like reaction inertia, on which a localized high‐coordination structure can be easily formed for the favorable adsorption of reaction intermediates. However, for single‐atom lanthanum sites, due to the loss of all the outmost s and d electrons, the practically vacuous outmost orbitals are stable but sleepy for the oxygen reduction reaction (ORR). Here, we synthesize a novel dual‐atom La catalyst onto N‐doped graphene (La 2 ‐NG) by a Joule ultrafast heating method, which shows a half‐wave potential of 0.893 V for the ORR. The La 2 ‐NG‐assembled zinc–air battery demonstrates a great open circuit voltage of 1.52 V and a maximal power density of 192 mW cm −2 . Operando X‐ray absorption spectra reveal the change of valence states of La and the dynamic structural evolution of the La 2 ‐N 6 moiety embedded onto the graphene during the ORR, through which the adsorption/desorption of oxygen reduction intermediates can be reasonably regulated. Theoretical calculations further demonstrate that the La 2 ‐N 6 structure can decrease the reaction energy barrier and promote charge transfer.