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<p>Efficient metal-free oxygen reduction reaction (ORR) electrocatalysts are vital for sustainable fuel cells. Density functional theory (DFT) is employed to investigate heteroatom doped carbon nanocones (CNCs) for 4e<sup>−</sup> and 2e<sup>−</sup> pathways. The nitrogen at the apex (N<sub>a</sub>), boron (B<sub>o</sub>) and phosphorus (P<sub>o</sub>) at ortho positions were investigated as potential active sites within the N<sub>a</sub>B<sub>o</sub>P<sub>o</sub>-CNC scaffold. Results indicate that the scaffold favors ORR, identifying the N<sub>a</sub> site as the optimal 4e<sup>−</sup> active center. The N<sub>a</sub> site exhibited a reaction free energy change with balanced thermodynamic profile, Gibbs free energy values ranging from −&#xa0;1.05 to −&#xa0;1.33&#xa0;eV and the *OOH → *O + H<sub>2</sub>O transition (0.22&#xa0;eV) identified as potential determining step (PDS) for 4e<sup>−</sup> pathway. The enhanced Fermi-level states increased the metallic character and dynamic charge fluctuations (6.08 e<sup>−</sup> to 6.22 e<sup>−</sup>) enabling rapid charge transfer, preventing surface poisoning observed at B<sub>o</sub> and P<sub>o</sub> sites. The 55 ° apical curvature of N<sub>a</sub>B<sub>o</sub>P<sub>o</sub>-CNC intensified N-2p/O-2p orbital overlap, promoting electron back-donation to O<sub>2</sub>-π* orbitals of the intermediates that lower the O–O bond cleavage barrier. Comparative CNT doping revealed a + 0.25&#xa0;eV barrier, demonstrating how N<sub>a</sub>B<sub>o</sub>P<sub>o</sub>-CNC curvature facilitates 4e<sup>−</sup> reduction to water. Intrinsic curvature and positional sensitivity are thus decisive for high-performance metal-free ORR electrocatalysts.</p> Graphical abstract <p></p>

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Doped nanocones as metal-free electrocatalysts for efficient oxygen reduction reaction: a DFT study

  • 期刊论文

  • 发表日期：

    2026年7月6日

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  • Muraledharan Shyama,
  • Ayesha Adel Alrustamani,
  • Mahreen Arooj

摘要

Efficient metal-free oxygen reduction reaction (ORR) electrocatalysts are vital for sustainable fuel cells. Density functional theory (DFT) is employed to investigate heteroatom doped carbon nanocones (CNCs) for 4e− and 2e− pathways. The nitrogen at the apex (Na), boron (Bo) and phosphorus (Po) at ortho positions were investigated as potential active sites within the NaBoPo-CNC scaffold. Results indicate that the scaffold favors ORR, identifying the Na site as the optimal 4e− active center. The Na site exhibited a reaction free energy change with balanced thermodynamic profile, Gibbs free energy values ranging from − 1.05 to − 1.33 eV and the *OOH → *O + H2O transition (0.22 eV) identified as potential determining step (PDS) for 4e− pathway. The enhanced Fermi-level states increased the metallic character and dynamic charge fluctuations (6.08 e− to 6.22 e−) enabling rapid charge transfer, preventing surface poisoning observed at Bo and Po sites. The 55 ° apical curvature of NaBoPo-CNC intensified N-2p/O-2p orbital overlap, promoting electron back-donation to O2-π* orbitals of the intermediates that lower the O–O bond cleavage barrier. Comparative CNT doping revealed a + 0.25 eV barrier, demonstrating how NaBoPo-CNC curvature facilitates 4e− reduction to water. Intrinsic curvature and positional sensitivity are thus decisive for high-performance metal-free ORR electrocatalysts.

Graphical abstract