Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710119, China.
Ruhr-Universität Bochum, Fakultät für Chemie und Biochemie, Anorganische Chemie I, Universitätsstrasse 150, 44801, Bochum, Germany.
Angew Chem Int Ed Engl. 2021 Mar 29;60(14):7576-7581. doi: 10.1002/anie.202015478. Epub 2021 Feb 26.
Nature uses Fe porphyrin sites for the oxygen reduction reaction (ORR). Synthetic Fe porphyrins have been extensively studied as ORR catalysts, but activity improvement is required. On the other hand, Fe porphyrins have been rarely shown to be efficient for the oxygen evolution reaction (OER). We herein report an enzyme-inspired Fe porphyrin 1 as an efficient catalyst for both ORR and OER. Complex 1, which bears a tethered imidazole for Fe binding, beats imidazole-free analogue 2, with an anodic shift of ORR half-wave potential by 160 mV and a decrease of OER overpotential by 150 mV to get the benchmark current density at 10 mA cm . Theoretical studies suggested that hydroxide attack to a formal Fe =O form the O-O bond. The axial imidazole can prevent the formation of trans HO-Fe =O, which is less effective to form O-O bond with hydroxide. As a practical demonstration, we assembled rechargeable Zn-air battery with 1, which shows equal performance to that with Pt/Ir-based materials.
自然界利用铁卟啉作为氧还原反应（ORR）的活性位点。合成铁卟啉作为 ORR 催化剂已被广泛研究，但仍需要提高其活性。另一方面，铁卟啉很少被证明对氧气析出反应（OER）有效。在此，我们报道了一种受酶启发的铁卟啉 1，它是一种高效的 ORR 和 OER 催化剂。该配合物 1 带有一个连接的咪唑配体用于 Fe 配位，其性能优于无咪唑配体的类似物 2，其 ORR 半波电位正向移动了 160 mV，OER 过电位降低了 150 mV，在 10 mA cm 时达到了基准电流密度。理论研究表明，OH 攻击 O-O 键中的形式 Fe =O。轴向咪唑可以防止形成 trans HO-Fe =O，后者对于与 OH 形成 O-O 键的效率较低。作为实际应用的演示，我们组装了带有 1 的可再充电锌空气电池，其性能与基于 Pt/Ir 的材料相当。
