Cation effects on CO<sub>2</sub> reduction catalyzed by single-crystal and polycrystalline gold under well-defined mass transport conditions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39919184.
- Also identified by DOI 10.1126/sciadv.adr6465 and PMC identifier 11804923.
- 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
The presence of alkali metal cations in the electrolyte substantially affects the reactivity and selectivity of electrochemical carbon dioxide (CO<sub>2</sub>) reduction (CO<sub>2</sub>R). This study examines the role of cations in CO<sub>2</sub>R on single-crystal and polycrystalline Au under controlled mass-transport conditions. It establishes that CO<sub>2</sub> adsorption is the rate-determining step regardless of cation type or surface structure. Density functional theory calculations show that electron transfer occurs to a solvated CO<sub>2</sub>-cation complex. A more positive potential of zero charge enhances CO<sub>2</sub>R activity only on Au with similar surface coordination. The symmetry factor (β) of the rate-determining step varies with surface structure and cation identity, with density functional theory calculations indicating β's sensitivity to surface and double-layer structures. These findings emphasize the importance of both surface and double-layer structures in understanding cation effects on CO<sub>2</sub>R.