Abstract Carbon materials doped with sulfur (S) and nitrogen (N) are prospective alternatives to Pt-based catalysts as oxygen reduction reaction (ORR) catalyst since they are inexpensive and highly catalytic active. However, the further advancement of catalysts is greatly hindered for its unclear and equivocal catalytic sites. Here, using density functional theory studies, we find that those inactive carbon atoms next to graphitic N become ORR catalytic sites after S doping, which is distinctly different from N-doped carbon materials where catalytic sites are introduced by pyridinic N. The electrochemical results show that increasing the content of graphitic N can lead to higher catalytic activity for S and N dual-doped carbon materials, which exhibits higher turnover frequency towards ORR than that of N-doped carbon materials. This work provides insights for further advancement of electrocatalysts via heteroatom doping.

中文翻译：

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石墨氮位点的活化以促进氧还原

摘要 掺杂硫 (S) 和氮 (N) 的碳材料作为氧还原反应 (ORR) 催化剂是 Pt 基催化剂的潜在替代品，因为它们价格低廉且催化活性高。然而，催化剂的进一步发展因其不明确和模棱两可的催化位点而受到极大阻碍。在这里，利用密度泛函理论研究，我们发现石墨 N 旁边的那些非活性碳原子在 S 掺杂后成为 ORR 催化位点，这与由吡啶 N 引入催化位点的 N 掺杂碳材料明显不同。电化学结果表明增加石墨 N 的含量可以导致更高的 S 和 N 双掺杂碳材料的催化活性，与 N 掺杂的碳材料相比，其对 ORR 的转换频率更高。