Porphyry-type aromatic macrocycles such as metallo-phthalocyanines and metallo-porphyrins as single-atomic-site catalysts usually have good catalytic oxygen reduction reaction (ORR) performance. However, the construction of dual active sites using these molecules and the interaction between the active sites have not been much explored. Herein, we developed a facile approach to construct the dual-atom Fe by organizing the face-to-face self-assembly of molecular iron phthalocyanine (FePc) and transforming it into nanorod-like architectures under microwave irradiation. The (001)-oriented growth induced by strong intermolecular π–π-stacking to frame the stable-phase FePc was observed in the self-assembled FePc nanorods. The nanorods exhibited superior ORR performance than molecular FePc and state-of-the-art 20% Pt/C in alkaline media (260 and 60 mV positive shifting in half-wave potential compared with the molecular FePc/C and 20% Pt/C). Theoretical studies on crystal structures and reaction mechanisms revealed that the self-tailored space (4.92) between two neighboring Fe active sites facilitated mutual coordination with dioxygen by forming a dual-atom Fe species of a trans-bridged peroxo adduct (Fe–O–O–Fe), which favored the cleavage of the O–O bond and the release of OH* intermediates, resulting in an increase in ORR activity. This investigation revealed the possibility of enhancing the electrocatalysts’ performances by assembly and tailoring of the active sites’ interactions.

中文翻译：

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通过分子酞菁的面对面组装构建双原子 Fe 以实现卓越的氧还原反应

金属酞菁和金属卟啉等卟啉型芳香族大环化合物作为单原子位点催化剂通常具有良好的催化氧还原反应（ORR）性能。然而，使用这些分子构建双活性位点以及活性位点之间的相互作用尚未得到太多探索。在此，我们开发了一种简便的方法来构建双原子 Fe，通过组织分子铁酞菁 (FePc) 的面对面自组装并在微波照射下将其转化为纳米棒状结构。在自组装的 FePc 纳米棒中观察到由强分子间 π-π 堆叠诱导的 (001) 取向生长以构筑稳定相 FePc。纳米棒在碱性介质中表现出优于分子 FePc 和最先进的 20% Pt/C 的 ORR 性能（与分子 FePc/C 和 20% Pt/C 相比，半波电位正移 260 和 60 mV ）。对晶体结构和反应机制的理论研究表明，两个相邻的 Fe 活性位点之间的自定制空间 (4.92) 通过形成反式桥接过氧加合物 (Fe-O-O) 的双原子 Fe 物种，促进了与分子氧的相互配位。 -Fe)，这有利于 O-O 键的断裂和 OH* 中间体的释放，导致 ORR 活性增加。这项研究揭示了通过组装和调整活性位点的相互作用来提高电催化剂性能的可能性。