Steering CO<sub>2</sub> electroreduction pathway toward ethanol via surface-bounded hydroxyl species-induced noncovalent interaction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36877842.
- Also identified by DOI 10.1073/pnas.2218987120 and PMC identifier 10089218.
- Licence recorded as CC BY-NC-ND.
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Abstract
Selective electroreduction of carbon dioxide (CO<sub>2</sub>RR) into ethanol at an industrially relevant current density is highly desired. However, it is challenging because the competing ethylene production pathway is generally more thermodynamically favored. Herein, we achieve a selective and productive ethanol production over a porous CuO catalyst that presents a high ethanol Faradaic efficiency (FE) of 44.1 ± 1.0% and an ethanol-to-ethylene ratio of 1.2 at a large ethanol partial current density of 501.0 ± 15.0 mA cm<sup>-2</sup>, in addition to an extraordinary FE of 90.6 ± 3.4% for multicarbon products. Intriguingly, we found a volcano-shaped relationship between ethanol selectivity and nanocavity size of porous CuO catalyst in the range of 0 to 20 nm. Mechanistic studies indicate that the increased coverage of surface-bounded hydroxyl species (*OH) associated with the nanocavity size-dependent confinement effect contributes to the remarkable ethanol selectivity, which preferentially favors the *CHCOH hydrogenation to *CHCHOH (ethanol pathway) via yielding the noncovalent interaction. Our findings provide insights in favoring the ethanol formation pathway, which paves the path toward rational design of ethanol-oriented catalysts.