Electron-rich palladium regulated by cationic vacancies in CoFe layered double hydroxide boosts electrocatalytic hydrodechlorination.

Palladium (Pd) is regarded as a promising electrocatalytic hydrodechlorination (EHDC) catalyst for the detoxification of halogenated phenols. Nevertheless, its intrinsic EHDC activity is seriously restricted by the hydrogen evolution reaction (HER), consuming the active hydrogen (H*) for EHDC. Here, we report a defect regulation strategy using cationic vacancies rich CoFe-LDH with coupling ultrafine Pd nanoparticles that induces optimized electron distribution of Pd to promote EHDC. The experimental and theoretical results reveal that superior EHDC performance of Pd@CoFe-LDH is attributed to the electron-rich Pd regulated by cationic vacancies in CoFe-LDH support, driving facile adsorption of halogenated phenols, high water activation ability and H* selectivity for EHDC. Our findings provide a versatile defect-regulating strategy to overcome the challenge in efficiency and selectivity of EHDC process.