Zhao Yonggui, Dongfang Nanchen, Huang Chong, Erni Rolf, Li Jingguo, Zhao Han, Pan Long, Iannuzzi Marcella, Patzke Greta R
Department of Chemistry, University of Zurich, Zurich, Switzerland.
Electron Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
Nat Commun. 2025 Jan 10;16(1):580. doi: 10.1038/s41467-025-55857-3.
The complexity of the intrinsic oxygen evolution reaction (OER) mechanism, particularly the precise relationships between the local coordination geometry of active metal centers and the resulting OER kinetics, remains to be fully understood. Herein, we construct a series of 3 d transition metal-incorporated cobalt hydroxide-based nanobox architectures for the OER which contain tetrahedrally coordinated Co(II) centers. Combination of bulk- and surface-sensitive operando spectroelectrochemical approaches reveals that tetrahedral Co(II) centers undergo a dynamic transformation into highly active Co(IV) intermediates acting as the true OER active species which activate lattice oxygen during the OER. Such a dynamic change in the local coordination geometry of Co centers can be further facilitated by partial Fe incorporation. In comparison, the formation of such active Co(IV) species is found to be hindered in CoOOH and Co-FeOOH, which are predominantly containing [CoO] and [Co/FeO] octahedra, respectively, but no mono-μ-oxo-bridged [CoO] moieties. This study offers a comprehensive view of the dynamic role of local coordination geometry of active metal centers in the OER kinetics.
本征析氧反应（OER）机理的复杂性，尤其是活性金属中心的局部配位几何结构与由此产生的OER动力学之间的精确关系，仍有待充分理解。在此，我们构建了一系列用于OER的含四面体配位Co（II）中心的3d过渡金属掺入氢氧化钴基纳米盒结构。体相和表面敏感的原位光谱电化学方法相结合表明，四面体Co（II）中心会动态转变为高活性Co（IV）中间体，这些中间体作为真正的OER活性物种，在OER过程中激活晶格氧。Co中心局部配位几何结构的这种动态变化可通过部分掺入Fe进一步促进。相比之下，发现在主要分别包含[CoO]和[Co/FeO]八面体但没有单μ-氧桥联[CoO]部分的CoOOH和Co-FeOOH中，这种活性Co（IV）物种的形成受到阻碍。这项研究全面展示了活性金属中心的局部配位几何结构在OER动力学中的动态作用。
