Surfactant-enhanced Cuδ+ and induced electrostatic forces promote the electrocatalytic deuteron-dechlorination of trichloroacetic acid

Electrocatalytic deuteron-dechlorination of trichloroacetic acid (TCAA) in D 2 O provides a green route to synthesize commercial acetic- d 3 acid- d (AA- d 4 ). Synthesizing AA- d 4 with a high Faradaic efficiency (FE) and reaction rate is highly challenging because of the difficult C−Cl bond deuteration of the 2-monochloroacetic-2,2- d 2 acid- d (MCAA- d 3 ) intermediate. Here, a quaternary ammonium salt surfactant-modified low-coordination copper electrocatalyst is designed, achieving TCAA-to-AA- d 4 with a 91% selectivity, 91% FE and 0.59 mmol h −1 reaction rate at −100 mA cm −2 . Mechanistic and kinetic studies reveal that the surfactant enhances the adsorption of MCAA- d 3 through electrostatic forces and increases the electron deficiency of Cu δ+ sites, which accelerates electron transfer and promotes C−Cl bond activation, increasing the AA- d 4 selectivity. Surfactant-induced low D 2 O coverage suppresses D 2 formation, improving the FE. AA- d 4 electrosynthesis (1.84 g) with a 30 mmol h −1 reaction rate and 65% FE at 600 mA cm −2 and deuterated drug applications demonstrate promising potential.