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  • Inverse potential scaling in co-electrocatalytic activity for CO 2 reduction through redox mediator tuning and catalyst design
Title: Inverse potential scaling in co-electrocatalytic activity for CO 2 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 (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.  more » « less
Award ID(s):
2018870
PAR ID:
10459060
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Chemical Science
Volume:
13
Issue:
33
ISSN:
2041-6520
Page Range / eLocation ID:
9595 to 9606
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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