Organometallic complexes with metal-nitrogen/carbon (M-N/C) coordination are the most important alternatives to precious metal catalysts for oxygen reduction and evolution reactions (ORR and OER) in energy conversion devices. Here, we designed and developed a range of molecule-level graphitic carbon nitride (g-C3N4) coordinated transition metals (M-C3N4) as a new generation of M-N/C catalysts for these oxygen electrode reactions. As a proof-of-concept example, we conducted theoretical evaluation and experimental validation on a cobalt-C3N4 catalyst with a desired molecular configuration, which possesses comparable electrocatalytic activity to that of precious metal benchmarks for the ORR and OER in alkaline media. The correlation of experimental and computational results confirms that this high activity originates from the precise M-N2 coordination in the g-C3N4 matrix. Moreover, the reversible ORR/OER activity trend for a wide variety of M-C3N4 complexes has been constructed to provide guidance for the molecular design of this promising class of catalysts.

中文翻译：

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分子级 g-C3N4 配位过渡金属作为新型氧电极反应电催化剂

具有金属-氮/碳 (MN/C) 配位的有机金属配合物是能量转换装置中用于氧还原和析出反应 (ORR 和 OER) 的贵金属催化剂的最重要替代品。在这里，我们设计并开发了一系列分子级石墨碳氮化物 (g-C3N4) 配位过渡金属 (M-C3N4) 作为用于这些氧电极反应的新一代 MN/C 催化剂。作为概念验证示例，我们对具有所需分子构型的钴-C3N4 催化剂进行了理论评估和实验验证，该催化剂具有与碱性介质中 ORR 和 OER 的贵金属基准相当的电催化活性。实验和计算结果的相关性证实，这种高活性源于 g-C3N4 矩阵中精确的 M-N2 协调。此外，已经构建了多种 M-C3N4 配合物的可逆 ORR/OER 活性趋势，为这类有前途的催化剂的分子设计提供指导。