Details

Autor(en) / Beteiligte

• Xu, Chao
• Guo, Peng‐Peng
• Yang, Kun‐Zu
• Lu, Chen
• Wei, Ping‐Jie
• Liu, Jin‐Gang

Titel

F‐Doped Co−N−C Catalysts for Enhancing the Oxygen Reduction Reaction in Zn‐Air Batteries

Ist Teil von

• ChemCatChem, 2023-06, Vol.15 (11), p.n/a

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Zn‐air battery is a promising next‐generation energy storage device. Its performance, however, is limited by a high overpotential resulted from the slow kinetics of the cathodic oxygen reduction reaction (ORR). This study reports a simple strategy for preparation of a fluorine‐doped Co−N−C composite as highly efficient electrocatalyst for ORR. The C@PVI‐(TPFC)Co‐800 catalyst was prepared by pyrolysis of F‐containing Co‐corrole that was assembled on PVI‐functionalized carbon black through the axial imidazole coordination (PVI=polyvinylimidazole, TPFC=5,10,15‐triperfluorophenyl‐21H, 22H‐corrole). The C@PVI‐(TPFC)Co‐800 catalyst exhibited much more positive ORR half‐wave potential (E1/2=0.88 V vs. RHE) than its counterpart C@PVI‐(TPC)Co‐800 (E1/2=0.82 V, TPC=5,10,15‐triphenyl‐21H, 22H‐corrole) without F‐doping in 0.1 M KOH electrolyte. C@PVI‐(TPFC)Co‐800 also achieved a greater kinetic current density and enhanced durability in alkaline media. In addition, a Zn‐air battery with C@PVI‐(TPFC)Co‐800 loaded at the cathode delivered much higher peak power density (Pmax=141 mW/cm2) and open‐circuit voltage (OCV=1.45 V) over the C@PVI‐(TPC)Co‐800 counterpart (Pmax=110 mW/cm2, OCV=1.39 V) and the commercial 20 % Pt/C (Pmax=119 mW/cm2, OCV=1.42 V) as well. The promoted catalyst performance for ORR was attributed to the increased specific surface area, more defects generated, and reduced electron density distribution around the Co metal center after F‐doping. The F‐doped Co−N−C catalyst exhibits impressively higher electrocatalytic activity and durability for oxygen reduction reaction in Zn‐air batteries than the counterpart without F‐doping and the commercial Pt/C catalyst as well.