Pressure dependence in aqueous-based electrochemical CO<sub>2</sub> reduction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 37221228.
- Also identified by DOI 10.1038/s41467-023-38775-0 and PMC identifier 10205702.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Electrochemical CO<sub>2</sub> reduction (CO<sub>2</sub>R) is an approach to closing the carbon cycle for chemical synthesis. To date, the field has focused on the electrolysis of ambient pressure CO<sub>2</sub>. However, industrial CO<sub>2</sub> is pressurized-in capture, transport and storage-and is often in dissolved form. Here, we find that pressurization to 50 bar steers CO<sub>2</sub>R pathways toward formate, something seen across widely-employed CO<sub>2</sub>R catalysts. By developing operando methods compatible with high pressures, including quantitative operando Raman spectroscopy, we link the high formate selectivity to increased CO<sub>2</sub> coverage on the cathode surface. The interplay of theory and experiments validates the mechanism, and guides us to functionalize the surface of a Cu cathode with a proton-resistant layer to further the pressure-mediated selectivity effect. This work illustrates the value of industrial CO<sub>2</sub> sources as the starting feedstock for sustainable chemical synthesis.