| Autor: |
Shaughnessy, Charles I., Sconyers, David J., Kerr, Tyler A., Lee, Hyun‐Jin, Subramaniam, Bala, Leonard, Kevin C., Blakemore, James D. |
| Předmět: |
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| Zdroj: |
ChemSusChem; 8/22/2019, Vol. 12 Issue 16, p3761-3768, 8p |
| Abstrakt: |
Multimolar CO2 concentrations are achieved in acetonitrile solutions containing supporting electrolyte at relatively mild CO2 pressures (<5 MPa) and ambient temperature. Such CO2‐rich, electrolyte‐containing solutions are termed as CO2‐eXpanded Electrolytes (CXEs) because significant volumetric expansion of the liquid phase accompanies CO2 dissolution. Cathodic polarization of a model polycrystalline gold electrode‐catalyst in CXE media enhances CO2 to CO conversion rates by up to an order of magnitude compared with those attainable at near‐ambient pressures, without loss of selectivity. The observed catalytic process intensification stems primarily from markedly increased CO2 availability. However, a non‐monotonic correlation between the dissolved CO2 concentration and catalytic activity is observed, with an optimum occurring at approximately 5 m CO2 concentration. At the highest applied CO2 pressures, catalysis is significantly attenuated despite higher CO2 concentrations and improved mass‐transport characteristics, attributed in part to increased solution resistance. These results reveal that pressure‐tunable CXE media can significantly intensify CO2 reduction rates over known electrocatalysts by alleviating substrate starvation, with CO2 pressure as a crucial variable for optimizing the efficiency of electrocatalytic CO2 conversion. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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