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

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.

Atomically Dispersed Fe Sites Regulated by Adjacent Single Co Atoms Anchored on N‐P Co‐Doped Carbon Structures for Highly Efficient Oxygen Reduction Reaction

“…[ 6–9 ] Compared with traditional catalysts, SACs offer distinct advantages, including reduced cost with tunable electronic properties and enhanced atomic utilization efficiency, making them highly promising for various electrocatalytic applications, particularly for reversible oxygen electrocatalysis. [ 10 ‐ 15 ]…”

Synthetic Principles of Spiky Au Nanoparticles

“…One can clearly see that these K-L plots overlap with each other, all of which exhibit excellent linearity and nearly the same slope. These results mean that the ORR catalyzed by them follows the same first-order kinetics. − In addition, the electron transfer number ( n ) in the ORR catalyzed by the as-prepared spiky Au@Au 11.8 Pd 88.2 NPs is calculated to be about 4.00 in the entire diffusion current platform within the range from 0.4 to 0.7 V (vs RHE), which is nearly the same as that ( n = 4.00) catalyzed by commercial Pt/C catalysts (Figure S26). These results indicate that the reduction pathway of O 2 to H 2 O catalyzed by the as-prepared spiky Au@Au 11.8 Pd 88.2 NPs is via a four-electron pathway. , …”

Fe-based dual-atom catalysts for the oxygen reduction reaction

“…Similar to doping S, P and O in Fe-based SACs to achieve optimal modulation of the electronic structure, this strategy has also been researched and used for tailoring Fe-based DACs. 72,74,75 For instance, Zeng et al constructed highly active Fe 2 N 5 P sites on P-doped hollow carbon supports. Theoretical calculations suggest that the presence of P atoms on the Fe 2 N 5 P sites is favorable for the formation of OOH* and consequently enhances their activity.…”