Molecular cobalt corrole complex for the heterogeneous electrocatalytic reduction of carbon dioxide.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31455766.
- Also identified by DOI 10.1038/s41467-019-11868-5 and PMC identifier 6711975.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electrochemical conversion of CO<sub>2</sub> to alcohols is one of the most challenging methods of conversion and storage of electrical energy in the form of high-energy fuels. The challenge lies in the catalyst design to enable its real-life implementation. Herein, we demonstrate the synthesis and characterization of a cobalt(III) triphenylphosphine corrole complex, which contains three polyethylene glycol residues attached at the meso-phenyl groups. Electron-donation and therefore reduction of the cobalt from cobalt(III) to cobalt(I) is accompanied by removal of the axial ligand, thus resulting in a square-planar cobalt(I) complex. The cobalt(I) as an electron-rich supernucleophilic d<sup>8</sup>-configurated metal centre, where two electrons occupy and fill up the antibonding d<sub>z</sub><sup>2</sup> orbital. This orbital possesses high affinity towards electrophiles, allowing for such electronically configurated metals reactions with carbon dioxide. Herein, we report the potential dependent heterogeneous electroreduction of CO<sub>2</sub> to ethanol or methanol of an immobilized cobalt A<sub>3</sub>-corrole catalyst system. In moderately acidic aqueous medium (pH = 6.0), the cobalt corrole modified carbon paper electrode exhibits a Faradaic Efficiency (FE%) of 48 % towards ethanol production.