Advanced Bifunctional Oxygen Reduction and Evolution Electrocatalyst Derived from Surface‐Mounted Metal–Organic Frameworks

• Published in: Angewandte Chemie International Edition Vol. 59; no. 14; pp. 5837 - 5843
• Main Authors: Li, Weijin, Xue, Song, Watzele, Sebastian, Hou, Shujin, Fichtner, Johannes, Semrau, A. Lisa, Zhou, Liujiang, Welle, Alexander, Bandarenka, Aliaksandr S., Fischer, Roland A.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 27.03.2020; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Batteries; Catalysts; Chemical reduction; Current density; derivatives; Electrocatalysts; Electrolytic cells; Fuel cells; Fuel technology; Iron compounds; Metal-organic frameworks; Nickel compounds; Oxygen; oxygen evolution reaction; Oxygen evolution reactions; oxygen reduction reaction; Oxygen reduction reactions; thin films; derivatives; oxygen evolution reaction; oxygen reduction reaction; Metal-organic frameworks; thin films
• ISSN: 1433-7851; 1521-3773; 1521-3773
• DOI: 10.1002/anie.201916507

Metal–organic frameworks (MOFs) and their derivatives are considered as promising catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), which are important for many energy provision technologies, such as electrolyzers, fuel cells and some types of advanced batteries. In this work, a “strain modulation” approach has been applied through the use of surface‐mounted NiFe‐MOFs in order to design an advanced bifunctional ORR/OER electrocatalyst. The material exhibits an excellent OER activity in alkaline media, reaching an industrially relevant current density of 200 mA cm−2 at an overpotential of only ≈210 mV. It demonstrates operational long‐term stability even at a high current density of 500 mA cm−2 and exhibits the so far narrowest “overpotential window” ΔEORR‐OER of 0.69 V in 0.1 m KOH with a mass loading being two orders of magnitude lower than that of benchmark electrocatalysts. A simple strain approach was explored to prepare a NiFe‐based ORR/OER electrocatalyst derived from surface‐mounted metal–organic frameworks by rational introduction of functional groups into the organic linker. The catalyst exhibits an excellent OER activity, reaching industrially relevant current densities. As a bifunctional catalyst, it demonstrates a narrow overpotential window of ≈0.69 V in 0.1 m KOH, surpassing reported state‐of‐the‐art systems.