Scholarlink

<p>Single-atom catalysts (SACs) are highly attractive for electrochemical energy conversion owing to their unique electronic structures, high intrinsic activity, and maximum atom utilization. Here, we report density functional theory (DFT) investigations of metal-doped porphyrins functionalized with electron-withdrawing (F) and electron-donating (NH₂) groups to elucidate their bifunctional catalytic activity toward the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Electronic structure analyses, including HOMO–LUMO distributions, molecular electrostatic potential (MESP), and X-ray absorption spectra (XAS), reveal that the NH₂-functionalized Rh-porphyrin system, (RhPp)N₈(NH₂)₈, exhibits a highly favorable electronic environment for catalytic activation. Free-energy calculations show that all ORR steps are exothermic with an overall ΔG of –4.79&#xa0;eV, while HER proceeds preferentially via the Volmer–Tafel pathway due to a lower Tafel barrier relative to the Heyrovsky step. Notably, the (RhPp)N₈(NH₂)₈ surface delivers exceptionally low overpotentials of 0.26&#xa0;V for ORR and –0.01&#xa0;V for HER, on par with benchmark Pt(111) (0.45&#xa0;V for ORR and –0.09&#xa0;V for HER). These results identify functionalized Rh-porphyrins as efficient bifunctional electrocatalysts, for next-generation fuel cells and water-splitting technologies.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Fluorine and Amine Functionalized Co, Rh, and Ir-Doped Porphyrins for Oxygen Reduction and Hydrogen Evolution Catalysis: A DFT Study

  • 期刊论文

  • 发表日期：

    2025年10月15日

查看全文
  • Angappan Kausalya,
  • Senthilkumar Lakshmipathi

摘要

Single-atom catalysts (SACs) are highly attractive for electrochemical energy conversion owing to their unique electronic structures, high intrinsic activity, and maximum atom utilization. Here, we report density functional theory (DFT) investigations of metal-doped porphyrins functionalized with electron-withdrawing (F) and electron-donating (NH₂) groups to elucidate their bifunctional catalytic activity toward the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). Electronic structure analyses, including HOMO–LUMO distributions, molecular electrostatic potential (MESP), and X-ray absorption spectra (XAS), reveal that the NH₂-functionalized Rh-porphyrin system, (RhPp)N₈(NH₂)₈, exhibits a highly favorable electronic environment for catalytic activation. Free-energy calculations show that all ORR steps are exothermic with an overall ΔG of –4.79 eV, while HER proceeds preferentially via the Volmer–Tafel pathway due to a lower Tafel barrier relative to the Heyrovsky step. Notably, the (RhPp)N₈(NH₂)₈ surface delivers exceptionally low overpotentials of 0.26 V for ORR and –0.01 V for HER, on par with benchmark Pt(111) (0.45 V for ORR and –0.09 V for HER). These results identify functionalized Rh-porphyrins as efficient bifunctional electrocatalysts, for next-generation fuel cells and water-splitting technologies.

Graphical Abstract