This work aims to obtain a fundamental understanding of active sites near stone-wales (SW) defects rich nitrogen-doped graphene (DG) with specific coordination of carbon atom rings. It reveals that the SW rich defects (e.g., pentagon (5), pentagon—octagon—pentagon (i.e. 585), or pentagon-heptagon-heptagon-pentagon (5775) rings, appears correspondingly with carbon rings that brought active sites during catalytic reactions. Moreover, we anchored dual isolated metallic atoms (Ni/Fe) on DG support via linkers (O/N) called NiFe-DG. X-ray absorption spectroscopy indicates Ni/Fe metal single atoms are embedded via Fe-N₄ and Ni-N₄ coordination on DG surfaces. It exhibits high catalytic activity for oxygen reduction reaction (ORR) with an onset potential of 0.97 V, a half-wave potential of 0.86 V, and diffusion current density of 5.7 mA cm^− 2, which is at par with commercial Pt/C. The catalyst shows superior stability, retained 82% of the initial current density even after 12 h under an applied potential of 0.86 V. Similarly, the oxygen evolution reaction (OER) overpotential of 358 mV was achieved at 10 mA cm^− 2 with a lower Tafel slope value (76 mV/dec) than commercial Pt/C. It maintains 85% stability for 12 h at a constant potential of 1.588 V, shows better stability than commercial Pt/C.

这项工作旨在获得对斯通威尔士 (SW) 缺陷附近的活性位点的基本了解，该缺陷富含氮掺杂石墨烯 (DG)，具有特定的碳原子环配位。它揭示了富含 SW 的缺陷（例如，五边形（5）、五边形-八边形-五边形（即585）或五边形-七边形-七边形-五边形（5775）环，相应地出现了碳环，这些碳环在催化过程中带来了活性位点此外，我们通过称为 NiFe-DG 的连接体 (O/N) 将双孤立金属原子 (Ni/Fe) 锚定在 DG 载体上。X 射线吸收光谱表明 Ni/Fe 金属单原子通过Fe-N ₄和镍-N ₄DG 表面上的协调。它表现出对氧还原反应（ORR）的高催化活性，起始电位为 0.97 V，半波电位为 0.86 V，扩散电流密度为 5.7 mA cm ^{- 2}，与商业 Pt/C 相当。该催化剂显示出优异的稳定性，即使在 0.86 V 的外加电位下 12 小时后仍保持初始电流密度的 82%。类似地，在 10 mA cm ⁻²下实现了 358 mV 的析氧反应 (OER) 过电位，而较低的Tafel 斜率值 (76 mV/dec) 比商业 Pt/C 高。它在 1.588 V 的恒定电位下保持 85% 的稳定性达 12 小时，显示出比商业 Pt/C 更好的稳定性。