Electrochemical CO2 and Proton Reduction by a Co(dithiacyclam) Complex

While [Ni(cyclam)]2+ and [Ni(dithiacyclam)]2+ complexes were shown to be potent electrocatalysts for the CO2 conversion, their respective Co complexes hitherto received only little attention. Herein, we report on the CoII complexes of the cyclam and dithiacyclam platform, describe their synthesis an...

Full description

Saved in:
Bibliographic Details
Published in:Zeitschrift für anorganische und allgemeine Chemie (1950) 2020-07, Vol.646 (13), p.746-753
Main Authors: Iffland, Linda, Siegmund, Daniel, Apfel, Ulf‐Peter
Format: Article
Language:English
Subjects:
Acetic acid
Carbon dioxide
Chemical reduction
Cobalt
Dithiacyclam
Electrocatalysis
Electrocatalysts
Glassy carbon
Hydrogen
Protons
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:While [Ni(cyclam)]2+ and [Ni(dithiacyclam)]2+ complexes were shown to be potent electrocatalysts for the CO2 conversion, their respective Co complexes hitherto received only little attention. Herein, we report on the CoII complexes of the cyclam and dithiacyclam platform, describe their synthesis and reveal their rich solvent dependent coordination chemistry. We show that sulfur implementation into the cyclam moiety leads to a switch from a low spin CoII complex in [Co(cyclam)]2+ to a high spin form in [Co(dithiacyclam)]2+. Notably, while both complexes are capable to perform the reduction of CO2 to CO, H2 formation is generally preferred. Along this line, the complexes were shown to enable proton reduction from acetic acid. However, in comparison to [Co(cyclam)]2+, the altered electronics make [Co(dithiacyclam)]2+ complexes prone to deposit on the glassy carbon working electrode over time leading to an overall low faradaic efficiency for the reduction of protons or CO2.
ISSN:0044-2313
1521-3749
DOI:10.1002/zaac.201900356