The oxygen reduction reaction (ORR) has been studied for decades due to its importance in fuel cells or batteries. Carbon-based materials decorated with few metal active sites are one of the options to replace and reduce the use of Pt metals. Here, we demonstrate the ORR on various intrinsically functionalized Fe/C₃N₄ nanotubes by density functional theory (DFT) calculations in both acidic and alkaline media. Most of the alkaline overpotentials are similar regardless of functionalization and are generally lower than those in the acidic media. On the other hand, systems with the intrinsically functionalized O₂ can dramatically and significantly lower the overpotentials in acidic media. Our results are consistent with the experimental data reported at different pH values and may correlate with the better performance observed in a higher O₂ extent environment in solution. This study provides experimentalists with a microscopic understanding of the different operating conditions of the ORR.

中文翻译：

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本质功能化的 Fe/C3N4 纳米管表现出 pH 依赖性的氧还原过电势

由于氧还原反应 (ORR) 在燃料电池或电池组中的重要性，人们对其进行了数十年的研究。装饰有少量金属活性位点的碳基材料是替代和减少铂金属使用的选择之一。在这里，我们通过密度泛函理论 (DFT) 计算在酸性和碱性介质中证明了各种本质功能化的 Fe/C ₃ N ₄纳米管的 ORR 。无论官能化如何，大多数碱性过电势都是相似的，并且通常低于酸性介质中的过电势。另一方面，具有本质功能化 O _{2 的}系统可以显着降低酸性介质中的过电势。我们的结果与在不同pH值下报告的实验数据一致，并且可能与在溶液中较高O ₂程度环境中观察到的更好性能相关。这项研究为实验人员提供了对 ORR 不同操作条件的微观了解。