Inverse potential scaling in co-electrocatalytic activity for CO reduction through redox mediator tuning and catalyst design
Electrocatalytic CO 2 reduction is an attractive strategy to mitigate the continuous rise in atmospheric CO 2 concentrations and generate value-added chemical products. A possible strategy to increase the activity of molecular systems for these reactions is the co-catalytic use of redox mediators (R...
Gespeichert in:
Veröffentlicht in: | Chemical science (Cambridge) 2022-08, Vol.13 (33), p.9595-966 |
---|---|
Hauptverfasser: | , , , , , , |
Format: | Artikel |
Sprache: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Electrocatalytic CO
2
reduction is an attractive strategy to mitigate the continuous rise in atmospheric CO
2
concentrations and generate value-added chemical products. A possible strategy to increase the activity of molecular systems for these reactions is the co-catalytic use of redox mediators (RMs), which direct reducing equivalents from the electrode surface to the active site. Recently, we demonstrated that a sulfone-based RM could trigger co-electrocatalytic CO
2
reduction
via
an inner-sphere mechanism under aprotic conditions. Here, we provide support for inner-sphere cooperativity under protic conditions by synthetically modulating the mediator to increase activity at lower overpotentials (inverse potential scaling). Furthermore, we show that both the intrinsic and co-catalytic performance of the Cr-centered catalyst can be enhanced by ligand design. By tuning both the Cr-centered catalyst and RM appropriately, an optimized co-electrocatalytic system with quantitative selectivity for CO at an overpotential (
η
) of 280 mV and turnover frequency (TOF) of 194 s
−1
is obtained, representing a three-fold increase in co-catalytic activity at 130 mV lower overpotential than our original report. Importantly, this work lays the foundation of a powerful tool for developing co-catalytic systems for homogeneous electrochemical reactions.
The use of sulfone-based redox mediators in electrocatalytic CO
2
reduction by Cr-centered complexes enhances the turnover frequencies at lower overpotentials
via
inner-sphere electron transfer and pancake bonding. |
---|---|
ISSN: | 2041-6520 2041-6539 |
DOI: | 10.1039/d2sc03258a |