Electrocatalytic synthesis of adipic acid coupled with H<sub>2</sub> production enhanced by a ligand modification strategy.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36008416.
- Also identified by DOI 10.1038/s41467-022-32769-0 and PMC identifier 9411531.
- 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
Adipic acid is an important building block of polymers, and is commercially produced by thermo-catalytic oxidation of ketone-alcohol oil (a mixture of cyclohexanol and cyclohexanone). However, this process heavily relies on the use of corrosive nitric acid while releases nitrous oxide as a potent greenhouse gas. Herein, we report an electrocatalytic strategy for the oxidation of cyclohexanone to adipic acid coupled with H<sub>2</sub> production over a nickel hydroxide (Ni(OH)<sub>2</sub>) catalyst modified with sodium dodecyl sulfonate (SDS). The intercalated SDS facilitates the enrichment of immiscible cyclohexanone in aqueous medium, thus achieving 3.6-fold greater productivity of adipic acid and higher faradaic efficiency (FE) compared with pure Ni(OH)<sub>2</sub> (93% versus 56%). This strategy is demonstrated effective for a variety of immiscible aldehydes and ketones in aqueous solution. Furthermore, we design a realistic two-electrode flow electrolyzer for electrooxidation of cyclohexanone coupling with H<sub>2</sub> production, attaining adipic acid productivity of 4.7 mmol coupled with H<sub>2</sub> productivity of 8.0 L at 0.8 A (corresponding to 30 mA cm<sup>-2</sup>) in 24 h.