Reaction Pathways for Oxygen Evolution Promoted by Cobalt Catalyst
- 17 September 2013
- journal article
- research article
- Published by American Chemical Society (ACS) in Journal of the American Chemical Society
- Vol. 135 (41), 15353-15363
- https://doi.org/10.1021/ja401797v
Abstract
The in-depth understanding of the molecular mechanisms regulating the water oxidation catalysis is of key relevance for the rationalization and the design of efficient oxygen evolution catalysts based on earth-abundant transition metals. Performing ab initio DFT+U molecular dynamics calculations of cluster models in explicit water solution, we provide insight into the pathways for oxygen evolution of a cobalt-based catalyst (CoCat). The fast motion of protons at the CoCat/water interface and the occurrence of cubane-like Co-oxo units at the catalyst boundaries are the keys to unlock the fast formation of O–O bonds. Along the resulting pathways, we identified the formation of Co(IV)-oxyl species as the driving ingredient for the activation of the catalytic mechanism, followed by their geminal coupling with O atoms coordinated by the same Co. Concurrent nucleophilic attack of water molecules coming directly from the water solution is discouraged by high activation barriers. The achieved results suggest also interesting similarities between the CoCat and the Mn4Ca-oxo oxygen evolving complex of photosystem II.Keywords
This publication has 49 references indexed in Scilit:
- A molecular ruthenium catalyst with water-oxidation activity comparable to that of photosystem IINature Chemistry, 2012
- Electrosynthesis, functional, and structural characterization of a water-oxidizing manganese oxideEnergy & Environmental Science, 2012
- Structure and Valency of a Cobalt−Phosphate Water Oxidation Catalyst Determined by in Situ X-ray SpectroscopyJournal of the American Chemical Society, 2010
- EPR Evidence for Co(IV) Species Produced During Water Oxidation at Neutral pHJournal of the American Chemical Society, 2010
- Cobalt−Oxo Core of a Water-Oxidizing Catalyst FilmJournal of the American Chemical Society, 2009
- First-principles study for low-spinwith a structurally consistent HubbardPhysical Review B, 2009
- Electrolyte-Dependent Electrosynthesis and Activity of Cobalt-Based Water Oxidation CatalystsJournal of the American Chemical Society, 2009
- Cobalt–phosphate oxygen-evolving compoundChemical Society Reviews, 2008
- In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co 2+Science, 2008
- Model supercell local-density calculations of theexcitation spectra in NiOPhysical Review B, 1986