Heteroatom‐doped Fe‐NC catalyst has emerged as one of the most promising candidates to replace noble metal‐based catalysts for highly efficient oxygen reduction reaction (ORR). However, delicate controls over their structure parameters to optimize the catalytic efficiency and molecular‐level understandings of the catalytic mechanism are still challenging. Herein, a novel pyrrole–thiophene copolymer pyrolysis strategy to synthesize Fe‐isolated single atoms on sulfur and nitrogen‐codoped carbon (Fe‐ISA/SNC) with controllable S, N doping is rationally designed. The catalytic efficiency of Fe‐ISA/SNC shows a volcano‐type curve with the increase of sulfur doping. The optimized Fe‐ISA/SNC exhibits a half‐wave potential of 0.896 V (vs reversible hydrogen electrode (RHE)), which is more positive than those of Fe‐isolated single atoms on nitrogen codoped carbon (Fe‐ISA/NC, 0.839 V), commercial Pt/C (0.841 V), and most reported nonprecious metal catalysts. Fe‐ISA/SNC is methanol tolerable and shows negligible activity decay in alkaline condition during 15 000 voltage cycles. X‐ray absorption fine structure analysis and density functional theory calculations reveal that the incorporated sulfur engineers the charges on N atoms surrounding the Fe reactive center. The enriched charge facilitates the rate‐limiting reductive release of OH* and therefore improved the overall ORR efficiency.

中文翻译：

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高效热氧还原反应的共聚热解策略在S，N共掺杂碳上形成Fe分离的单原子

杂原子掺杂的Fe-NC催化剂已成为最有希望的替代物之一，以取代基于贵金属的催化剂以实现高效的氧还原反应（ORR）。但是，对其结构参数进行精细控制以优化催化效率和对催化机理的分子水平的了解仍然具有挑战性。在此，合理设计了一种新颖的吡咯-噻吩共聚物热解策略，以可控的S，N掺杂合成硫和氮共掺杂碳（Fe-ISA / SNC）上的Fe分离的单原子。Fe‐ISA / SNC的催化效率随着硫掺杂的增加而呈现出火山型曲线。经过优化的Fe-ISA / SNC的半波电势为0.896 V（vs可逆氢电极（RHE）），与在氮共掺杂碳（Fe-ISA / NC，0.839 V），商用Pt / C（0.841 V）和大多数报道的非贵金属催化剂上的Fe隔离单原子相比，它们具有更强的正性。Fe‐ISA / SNC具有甲醇耐受性，并且在15 000个电压循环中，碱性条件下的活性衰减可忽略不计。X射线吸收精细结构分析和密度泛函理论计算表明，掺入的硫​​能使Fe反应中心周围的N原子上的电荷发生变化。富集的电荷促进了OH *的限速还原释放，因此提高了整体ORR效率。X射线吸收精细结构分析和密度泛函理论计算表明，掺入的硫​​能使Fe反应中心周围的N原子上的电荷发生变化。富集的电荷促进了OH *的限速还原释放，因此提高了整体ORR效率。X射线吸收精细结构分析和密度泛函理论计算表明，掺入的硫​​能使Fe反应中心周围的N原子上的电荷发生变化。富集的电荷促进了OH *的限速还原释放，因此提高了整体ORR效率。