Operando monitoring of the functional role of tetrahedral cobalt centers for the oxygen evolution reaction

Yonggui Zhao; Nanchen Dongfang; Chong Huang; Rolf Erni; Jingguo Li; Han Zhao; Long Pan; Marcella Iannuzzi; Greta R Patzke

doi:10.1038/s41467-025-55857-3

Operando monitoring of the functional role of tetrahedral cobalt centers for the oxygen evolution reaction

Nat Commun. 2025 Jan 10;16(1):580. doi: 10.1038/s41467-025-55857-3.

Authors

Yonggui Zhao¹, Nanchen Dongfang², Chong Huang², Rolf Erni³, Jingguo Li^{4

5}, Han Zhao², Long Pan⁶, Marcella Iannuzzi², Greta R Patzke⁷

Affiliations

¹ Department of Chemistry, University of Zurich, Zurich, Switzerland. yonggui.zhao@chem.uzh.ch.
² Department of Chemistry, University of Zurich, Zurich, Switzerland.
³ Electron Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland.
⁴ Department of Environmental Science and Engineering, CAS Key Laboratory of Urban Pollutant Conversion, University of Science and Technology of China, Hefei, China.
⁵ Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden.
⁶ Key Laboratory of Advanced Metallic Materials of Jiangsu Province, School of Materials Science and Engineering, Southeast University, Nanjing, China.
⁷ Department of Chemistry, University of Zurich, Zurich, Switzerland. greta.patzke@chem.uzh.ch.

Abstract

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 [Co^IIIO₆] and [Co^II/Fe^IIIO₆] octahedra, respectively, but no mono-μ-oxo-bridged [Co^IIO₄] moieties. This study offers a comprehensive view of the dynamic role of local coordination geometry of active metal centers in the OER kinetics.