Fe/Co dual metal catalysts modulated by S-ligands for efficient acidic oxygen reduction in PEMFC
Feng Liu, Lei Shi, Xuanni Lin, Biao Zhang, Yongde Long, Fenghui Ye, Riqing Yan, Ruyi Cheng, Chuangang Hu, Dong Liu, Jieshan Qiu, Liming Dai
Abstract
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 ( E 1/2 ) 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.