Doughty Thomas, Zingl Andrea, Wünschek Maximilian, Pichler Christian M, Watkins Matthew B, Roy Souvik
School of Chemistry, University of Lincoln, Green Lane, Lincoln LN6 7DL, U.K.
Institute of Applied Physics, TU Vienna, Wiedner Hauptstraße 8-10, Vienna 1040, Austria.
ACS Appl Mater Interfaces. 2024 Aug 7;16(31):40814-40824. doi: 10.1021/acsami.4c03262. Epub 2024 Jul 23.
Metal-organic frameworks (MOFs) are increasingly being investigated as electrocatalysts for the oxygen evolution reaction (OER) due to their unique modular structures that present a hybrid between molecular and heterogeneous catalysts, featuring well-defined active sites. However, many fundamental questions remain open regarding the electrochemical stability of MOFs, structural reconstruction of coordination sites, and the role of formed species. Here, we report the structural transformation of a surface-grown MOF containing cobalt nodes and 1,1'-ferrocenedicarboxylic acid linkers (denoted as CoFc-MOF) during the OER in alkaline electrolyte. and investigations of CoFc-MOF film suggest that the MOF acts as a precatalyst and undergoes a two-step restructuring process under operating conditions to generate a metal oxyhydroxide phase. The MOF-derived metal oxyhydroxide catalyst, supported on nickel foam electrodes, displays high activity toward the OER with an overpotential of 190 mV at a current density of 10 mA cm. While this study demonstrates the necessity of investigating structural evolution of MOFs during electrocatalysis, it also shows the potential of using MOFs as precursors in catalyst design.
金属有机框架材料（MOFs）因其独特的模块化结构而越来越多地被研究用作析氧反应（OER）的电催化剂，这种结构呈现出分子催化剂和多相催化剂之间的混合特性，具有明确的活性位点。然而，关于MOFs的电化学稳定性、配位点的结构重构以及生成物种的作用等许多基本问题仍未解决。在此，我们报道了一种在碱性电解质中进行OER过程中，含有钴节点和1,1'-二茂铁二甲酸连接体（记为CoFc-MOF）的表面生长MOF的结构转变。对CoFc-MOF薄膜的研究表明，该MOF作为一种预催化剂，在操作条件下经历两步重构过程以生成金属羟基氧化物相。负载在泡沫镍电极上的MOF衍生金属羟基氧化物催化剂对OER表现出高活性，在电流密度为10 mA cm时过电位为190 mV。虽然这项研究证明了研究MOFs在电催化过程中结构演变的必要性，但它也展示了将MOFs用作催化剂设计前体的潜力。
