Fe/Co dual metal catalysts modulated by S-ligands for efficient acidic oxygen reduction in PEMFC

Here, we report a conceptual strategy for introducing spatial sulfur (S)-bridge ligands to regulate the coordination environment of Fe-Co-N dual-metal centers (Spa-S-Fe,Co/NC). Benefiting from the electronic modulation, Spa-S-Fe,Co/NC catalyst showed remarkably enhanced oxygen reduction reaction (ORR) performance with a half-wave potential (E1/2) of 0.846 V and satisfactory long-term durability in acidic electrolyte. Combined experimental and theoretical studies revealed that the excellent acidic ORR activity with a remarkable stability observed for Spa-S-Fe,Co/NC is attributable to the optimal adsorption-desorption of ORR oxygenated intermediates achieved through charge-modulation of Fe-Co-N bimetallic centers by the spatial S-bridge ligands. These findings provide a unique perspective to regulate the local coordination environment of catalysts with dual-metal-centers to optimize their electrocatalytic performance.

Automated summary

Here, a conceptual strategy for introducing spatial sulfur (S)-bridge ligands to regulate the coordination environment of Fe-Co-N dual-metal centers (Spa-S-Fe,Co/NC) is reported. The Spa-S-Fe,Co/NC catalyst showed significantly enhanced oxygen reduction reaction (ORR) performance and satisfactory long-term durability in acidic electrolyte. Experimental and theoretical studies revealed that the excellent acidic ORR activity with remarkable stability observed for Spa-S-Fe,Co/NC is attributable to the charge-modulation of Fe-Co-N bimetallic centers by the spatial S-bridge ligands, achieving optimal adsorption-desorption of ORR oxygenated intermediates. These findings provide a unique perspective to optimize the electrocatalytic performance of catalysts with dual-metal centers by regulating their local coordination environment.