Work

Engineering CoN 4 and FeN 4 Dual Sites with Adjacent Nanoclusters on Flexible Porous Carbon Fibers for Enhanced Electrocatalytic Oxygen Reduction and Evolution

Year: 2024

Type: article

Abstract: Dual‐atom catalysts (DACs) possess tunable electronic structures and efficient atom utilization, making them highly promising for catalyzing the oxygen reduction reaction/oxygen evolution reaction (ORR/OER). However, achieving high catalytic activity and stability for both ORR and OER in DACs remains a challenge. Herein, a flexible membrane of porous carbon fiber anchored with atomically scattered CoN 4 /FeN 4 dual sites and adjacent Co 2 Fe 2 /Fe 5 nanoclusters (Co, Fe‐DACs/NCs@PCF) is synthesized. The local geometry and electronic structure of the CoN 4 /FeN 4 sites, which act as reaction centers for ORR/OER, are finely regulated by the neighboring Co 2 Fe 2 /Fe 5 nanoclusters. This unique structure imparts Co, Fe‐DACs/NCs@PCF with exceptional activity and durability toward ORR/OER, outperforming the performance of single‐atom catalysts containing only CoN 4 or FeN 4 sites, as well as commercial Pt/C and RuO 2 catalysts. Zinc–air battery employing a Co, Fe‐DACs/NCs@PCF cathode exhibits outstanding stability, maintaining cyclability for over 1500 h, outperforming a Pt/C + RuO 2 air cathode. Theoretical calculations highlight distinct synergies between Fe 5 (Co 2 Fe 2 ) clusters and FeN 4 (CoN 4 ) sites, which optimize the coupling strength of Fe(Co)─OH at the potential‐determining steps and thus improve ORR (OER) catalytic kinetics. This study lays a theoretical and practical foundation for rational design of heterostructure catalysts featuring coexisting DACs and nanoclusters within porous carbon fibers.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202418489