Single‐site molecular electrocatalysts, especially those that perform catalytic conversion of N2 to NH3 under mild conditions, are highly desirable to derive fundamental structure‐activity relations and as potential alternatives to the current energy‐consuming Haber‐Bosch ammonia production process. Combining theoretical calculations with experimental evidence, it has been shown that easily reducible cobalt porphyrins catalyze the six‐electron, six‐proton reduction of dinitrogen to NH3 at neutral pH and under ambient conditions. Two easily reducible N‐fused cobalt porphyrins – CoNHF and CoNHF(Br)2 – reveal NRR activity with Faradic efficiencies between 6 ‐ 7.5% with ammonia yield rates of 300 ‐ 340 µmol g‐1 h‐1. Contrary to this, much harder‐to‐reduce N‐fused porphyrins – CoNHF(Ph)2 and CoNHF(PE)2 – reveal no NRR activity. The present study highlights the significance of tuning the redox and structural properties of single‐site NRR electrocatalysts for improved NRR activity under mild conditions.

中文翻译：

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使用易还原的氮稠合钴卟啉电催化二氮还原为氨


单中心分子电催化剂，特别是那些在温和条件下将 N2 催化转化为 NH3 的催化剂，非常适合导出基本的结构-活性关系，并作为当前耗能的 Haber-Bosch 氨生产过程的潜在替代品。理论计算与实验证据相结合，结果表明，在中性 pH 值和环境条件下，易还原的钴卟啉可催化六电子、六质子将二氮还原为 NH3。两种易还原的氮稠合钴卟啉——CoNHF 和 CoNHF(Br)2——揭示了 NRR 活性，法拉第效率在 6 ‐ 7.5% 之间，氨产率为 300 ‐ 340 µmol g‐1 h‐1。与此相反，更难还原的 N 融合卟啉——CoNHF(Ph)2 和 CoNHF(PE)2——没有显示出 NRR 活性。本研究强调了调节单中心NRR电催化剂的氧化还原和结构特性对于在温和条件下提高NRR活性的重要性。