TY - JOUR
T1 - Axial Chlorine Induced Electron Delocalization in Atomically Dispersed FeN4 Electrocatalyst for Oxygen Reduction Reaction with Improved Hydrogen Peroxide Tolerance
AU - Sabhapathy, Palani
AU - Raghunath, Puttikam
AU - Sabbah, Amr
AU - Shown, Indrajit
AU - Bayikadi, Khasim Saheb
AU - Xie, Rui Kun
AU - Krishnamoorthy, Vimal
AU - Lin, Ming Chang
AU - Chen, Kuei Hsien
AU - Chen, Li Chyong
N1 - Publisher Copyright:
© 2023 Wiley-VCH GmbH.
PY - 2023/11/8
Y1 - 2023/11/8
N2 - Atomically dispersed iron sites on nitrogen-doped carbon (Fe-NC) are the most active Pt-group-metal-free catalysts for oxygen reduction reaction (ORR). However, due to oxidative corrosion and the Fenton reaction, Fe-NC catalysts are insufficiently active and stable. Herein, w e demonstrated that the axial Cl-modified Fe-NC (Cl-Fe-NC) electrocatalyst is active and stable for the ORR in acidic conditions with high H2O2 tolerance. The Cl-Fe-NC exhibits excellent ORR activity, with a high half-wave potential (E1/2) of 0.82 V versus a reversible hydrogen electrode (RHE), comparable to Pt/C (E1/2 = 0.85 V versus RHE) and better than Fe-NC (E1/2 = 0.79 V versus RHE). X-ray absorption spectroscopy analysis confirms that chlorine is axially integrated into the FeN4. More interestingly, compared to Fe-NC, the Fenton reaction is markedly suppressed in Cl-Fe-NC. In situ electrochemical impedance spectroscopy reveals that Cl-Fe-NC provides efficient electron transfer and faster reaction kinetics than Fe-NC. Density functional theory calculations reveal that incorporating Cl into FeN4 can drive the electron density delocalization of the FeN4 site, leading to a moderate adsorption free energy of OH* (∆GOH*), d-band center, and a high onset potential, and promotes the direct four-electron-transfer ORR with weak H2O2 binding ability compared to Cl-free FeN4, indicating superior intrinsic ORR activity.
AB - Atomically dispersed iron sites on nitrogen-doped carbon (Fe-NC) are the most active Pt-group-metal-free catalysts for oxygen reduction reaction (ORR). However, due to oxidative corrosion and the Fenton reaction, Fe-NC catalysts are insufficiently active and stable. Herein, w e demonstrated that the axial Cl-modified Fe-NC (Cl-Fe-NC) electrocatalyst is active and stable for the ORR in acidic conditions with high H2O2 tolerance. The Cl-Fe-NC exhibits excellent ORR activity, with a high half-wave potential (E1/2) of 0.82 V versus a reversible hydrogen electrode (RHE), comparable to Pt/C (E1/2 = 0.85 V versus RHE) and better than Fe-NC (E1/2 = 0.79 V versus RHE). X-ray absorption spectroscopy analysis confirms that chlorine is axially integrated into the FeN4. More interestingly, compared to Fe-NC, the Fenton reaction is markedly suppressed in Cl-Fe-NC. In situ electrochemical impedance spectroscopy reveals that Cl-Fe-NC provides efficient electron transfer and faster reaction kinetics than Fe-NC. Density functional theory calculations reveal that incorporating Cl into FeN4 can drive the electron density delocalization of the FeN4 site, leading to a moderate adsorption free energy of OH* (∆GOH*), d-band center, and a high onset potential, and promotes the direct four-electron-transfer ORR with weak H2O2 binding ability compared to Cl-free FeN4, indicating superior intrinsic ORR activity.
KW - Cl coordination
KW - FeN4
KW - Fenton reaction
KW - d-band center
KW - electron density
KW - oxygen reduction reaction
UR - http://www.scopus.com/inward/record.url?scp=85164476408&partnerID=8YFLogxK
U2 - 10.1002/smll.202303598
DO - 10.1002/smll.202303598
M3 - Article
AN - SCOPUS:85164476408
SN - 1613-6810
VL - 19
JO - Small
JF - Small
IS - 45
M1 - 2303598
ER -