In-situ structure and catalytic mechanism of NiFe and CoFe layered double hydroxides during oxygen evolution
Open Access
- 20 May 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature Communications
- Vol. 11 (1), 2522
- https://doi.org/10.1038/s41467-020-16237-1
Abstract
NiFe and CoFe (MFe) layered double hydroxides (LDHs) are among the most active electrocatalysts for the alkaline oxygen evolution reaction (OER). Herein, we combine electrochemical measurements, operando X-ray scattering and absorption spectroscopy, and density functional theory (DFT) calculations to elucidate the catalytically active phase, reaction center and the OER mechanism. We provide the first direct atomic-scale evidence that, under applied anodic potentials, MFe LDHs oxidize from as-prepared α-phases to activated γ-phases. The OER-active γ-phases are characterized by about 8% contraction of the lattice spacing and switching of the intercalated ions. DFT calculations reveal that the OER proceeds via a Mars van Krevelen mechanism. The flexible electronic structure of the surface Fe sites, and their synergy with nearest-neighbor M sites through formation of O-bridged Fe-M reaction centers, stabilize OER intermediates that are unfavorable on pure M-M centers and single Fe sites, fundamentally accounting for the high catalytic activity of MFe LDHs.This publication has 76 references indexed in Scilit:
- Theoretical Investigation of the Activity of Cobalt Oxides for the Electrochemical Oxidation of WaterJournal of the American Chemical Society, 2013
- An Investigation of Thin-Film Ni–Fe Oxide Catalysts for the Electrochemical Evolution of OxygenJournal of the American Chemical Society, 2013
- Universality in Oxygen Evolution Electrocatalysis on Oxide SurfacesChemCatChem, 2011
- The role of non-covalent interactions in electrocatalytic fuel-cell reactions on platinumNature Chemistry, 2009
- Topochemical Synthesis of Monometallic (Co2+–Co3+) Layered Double Hydroxide and Its Exfoliation into Positively Charged Co(OH)2 NanosheetsAngewandte Chemie, 2007
- An Octahedral Coordination Complex of Iron(VI)Science, 2006
- Phase Stability of Nickel Hydroxides and OxyhydroxidesJournal of the Electrochemical Society, 2006
- The Steady State of Heterogeneous Catalysis, Studied by First-Principles Statistical MechanicsPhysical Review Letters, 2004
- The Catalysis of the Oxygen Evolution Reaction by Iron Impurities in Thin Film Nickel Oxide ElectrodesJournal of the Electrochemical Society, 1987
- Die Struktur höherer NickelhydroxydeZeitschrift für anorganische und allgemeine Chemie, 1950