Probing the Local Reaction Environment During High Turnover Carbon Dioxide Reductionwith Ag-Based Gas DiffusionElectrodes
Creators
- 1. Analytical Chemistry—Center for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr.150, 44780 Bochum (Germany)
- 2. Institute of Chemical and Electrochemical Process Engineering, Clausthal University of Technology, Leibnizstr. 17, 38678 Clausthal-Zellerfeld (Germany)
Description
Discerning the influence of electrochemical reactions on the electrode microenvironment is an unavoidable topic for electrochemical reactions that involve the production of OH- and the consumption of water.That is particularly true for the carbondioxide reduction reaction (CO2RR), which together with the competing hydrogen evolution reaction (HER) exert changes in the local OH- and H2O activity that in turn can possibly affect activity, stability, and selectivity of the CO2RR. We determine the local OH- and H2O activity in close proximity to a CO2-converting Ag-based gas diffusion electrode (GDE) with product analysis using gas chromatography. A Pt nanosensor is positioned in the vicinity of the working GDE using shear-force-based scanning electrochemical microscopy (SECM) approach curves, which allows monitoring changes invoked by reactions proceeding within an otherwise inaccessible porous GDE by potentiodynamic measurements at the Pt-tip nanosensor. We show that high turnover HER/CO2RR at a GDE lead to modulations of the alkalinity of the local electrolyte, that resemble a 16M KOH solution, variations that are in turn linked to the reaction selectivity.
Notes
Files
DOI10.1002chem.202100387.pdf
Files
(1.3 MB)
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