Direct-Coupling O₂ Bond Forming Pathway in Cobalt Oxide Water Oxidation Catalysts

We report a catalytic mechanism for water oxidation in a cobalt oxide cubane model compound, in which the crucial O–O bond formation step takes place by direct coupling between two CoIV(O) metal oxo groups. Our results are based upon density functional theory (DFT) calculations and are consistent wi...

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Bibliographic Details
Main Authors: Wang, Lee-Ping, Van Voorhis, Troy
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: American Chemical Society 2012
Online Access:http://hdl.handle.net/1721.1/73954
https://orcid.org/0000-0001-7111-0176
Description
Summary:We report a catalytic mechanism for water oxidation in a cobalt oxide cubane model compound, in which the crucial O–O bond formation step takes place by direct coupling between two CoIV(O) metal oxo groups. Our results are based upon density functional theory (DFT) calculations and are consistent with experimental studies of the CoPi water oxidation catalyst. The computation of energetics and barriers for the steps leading up to and including the O–O bond formation uses an explicit solvent model within a hybrid quantum mechanics/molecular mechanics (QM/MM) framework, and captures the essential hydrogen-bonding effects and dynamical flexibility of this system.