biostudies-literatureUnknownZhong XSingle-atom catalysts (SACs) hold promise for addressing challenges of polysulfide shuttle and sluggish sulfur reduction reaction (SRR) in room-temperature (RT) Na-S batteries. However, their structural durability under harsh electrochemical conditions remains a critical concern. Herein, we propose an effective strategy to optimize and stabilize the active sites of Fe single atoms (Fe_SACS) by modulating the local geometries through axial fluorine (F) coordination, thus significantly alleviating the stability problems faced by conventional high-performance but deactivation-prone Fe-N-C catalysts. Density functional theory (DFT) calculations and experimental results confirm that the enhanced Fe-F interactions in the second shell layer play a key role in maintaining the structural Chemical sciencehttps://www.ebi.ac.uk/biostudies/studies/S-EPMC12442284biostudies-literatureAxial fluorine coordination boosts the activity and durability of Fe single-atom catalysts in room-temperature Na-S batteries.PMC12442284Cai DHuang YJi XHe ZCai JZhong XGeng ZHou HDeng WZou GfalseAxial fluorine coordination boosts the activity and durability of Fe single-atom catalysts in room-temperature Na-S batteries.Single-atom catalysts (SACs) hold promise for addressing challenges of polysulfide shuttle and sluggish sulfur reduction reaction (SRR) in room-temperature (RT) Na-S batteries. However, their structural durability under harsh electrochemical conditions remains a critical concern. Herein, we propose an effective strategy to optimize and stabilize the active sites of Fe single atoms (Fe_SACS) by modulating the local geometries through axial fluorine (F) coordination, thus significantly alleviating the stability problems faced by conventional high-performance but deactivation-prone Fe-N-C catalysts. Density functional theory (DFT) calculations and experimental results confirm that the enhanced Fe-F interactions in the second shell layer play a key role in maintaining the structural 2025-01-01T00:00:00Z2025 Sep2026-06-03T11:18:14.211Z2026-05-29T03:06:00.149ZS-EPMC124422844096916010.1039/d5sc05972k