In situ redox growth of Pd/CuOx for enhanced electrocatalytic degradation of organic chlorides via indirect atomic H* reduction

Abstract

Efficient utilization of atomic hydrogen (H*) is crucial for electrocatalytic dechlorination. We synthesized a Pd/CuOx cathode by atomic reconstruction to boost H* utilization, creating additional active sites within a biphasic interface. This enhanced H* generation degraded 2,4-dichlorophenoxyacetic acid (2,4-D) with a 96 % removal efficiency at 4 mA cm2 and 1.96 kWh m3 energy consumption. Cyclic voltammetry (CV) showed a 0.009 μmol cm2 increase H* on the Pd/CuOx cathode compared to the pristine Cu cathode. The contribution of H* to the electrocatalytic dechlorination process was further corroborated by scavenging experiments and electron spin resonance investigation. We then evaluated the toxicity of products during the degradation process. Density functional theory calculations revealed that the coordination structure between CuOx and Pd optimized the dissociation of H2O and the free adsorption energy of hydrogen. This research introduces an effective alternative to enhance the H* production for the removal of organochlorine compounds from wastewater.