Abstract
Strategic active site organization is imperative for the advancement of effective and long-lasting cata-lysts of oxygen reduction reactions.However,the controllable multi-active site design is a highly intricate topic for catalyst synthesis.Employing pre-trapping and post-activation strategy,Fe-N bonding structure and S,Se functionalized heteroatom are integrated into a conductive porous carbon.In this process,the nitrogen-abundant polymer 1,3,5-triformylbenzene-tris(4-aminophenyl)benzene(Tf-TAPA)adsorbs Fe3+under the intrinsically metal anchoring ability of N atoms and simultaneously in-situ assembles long-chain thiophene-S.Subsequently,the Fe3+is transformed into Fe-Nx moieties with the conversion of the organic chain to incompletely graphitized carbon.Furthermore,the alteration of the electronic configu-ration achieved through the introduction of dual-atom S and Se leads to a pronounced enhancement in catalytic efficiency.Benefitting from the Fe-Nx bonding structure,dense structural defects,and conductive carbon networks,the resultant Fe-S,Se/NCNs possesses a positive half-wave potential of 0.86 V and a 90％current retention rate,outstripping the Pt/C benchmark.Moreover,the liquid and flexible ZAB driven by Fe-S,Se/NCNs achieves large power densities of 259.7 and 164.7 mW/cm2,respectively.This study pro-vides a new comprehension in developing an efficient and stable M-N-C oxygen electrocatalyst.
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