| Autor: |
Chauhan, Piyush, Herranz, Juan, Winzely, Maximilian, Georgi, Maximilian, Khavlyuk, Pavel, Eychmüller, Alexander, Schmidt, Thomas J. |
| Zdroj: |
The Journal of Physical Chemistry - Part C; August 2023, Vol. 127 Issue: 33 p16453-16463, 11p |
| Abstrakt: |
Despite its increased relevance for the ongoing energy transition, the CO2-reduction reaction (CO2RR) continues to be poorly understood, particularly in the context of how its kinetics and product outcome are affected by surface-specific parameters such as the interfacial pH. The latter has received increased attention lately, with numerous studies reporting its impact on the product distribution of the CO2-electroreduction reaction but failing to quantify it reliably due to the poorly defined mass transport properties of the electrochemical cells in which most of those studies were performed. With this motivation, herein we investigate the CO2RR on polycrystalline Au and a Au aerogel in a rotating ring-disk electrode (RRDE) setup characterized by its well-defined hydrodynamic properties and quantify these surfaces’ CO2-to-CO conversion performance and interfacial pH using a Au or an IrOxring, respectively. The experimental ring pH was found to be in close agreement with the values computed from a mathematical model, from which we estimated disk surface pH maxima of ∼9.2 vs ∼9.0 for AuAGvs AuPC. The subsequent quantification of CO-specific kinetic currents made possible by the use of this RRDE approach unveiled that the polycrystalline surface features an ∼2-fold larger Au-surface-specific current than the aerogel, thus hinting at the existence of a roughness factor effect on this key performance metric. |
| Databáze: |
Supplemental Index |
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