Pd-dispersed Cu2O/Cu Catalysts for Electrochemical Nitrate Reduction

Electrochemical nitrate reduction reaction (NITRR) is a promising approach to removing nitrogen pollutants in wastewater. Herein, Pd-Cu2O/CF was synthesized using a two-step method: in situ growth of cubic Cu2O nanoparticles on Cu foam (CF) and electrodeposited palladium (Pd) metal. The cubic Cu2O nanoparticles provide abundant hydrogen/oxygen-adsorbing sites, and Pd sites with outstanding hydrogen adsorption-desorption features generate more active hydrogen (H*), both of which effectively improve the activity for NITRR. It was demonstrated that Pd-Cu2O/CF had excellent performance with nitrate removal of 99.7% within 60 min. To remove total nitrogen (TN) from wastewater, NH4+ was completely oxidized to N-2 within 120 min by adding Cl-, and the TN removal was up to 99.9%. Moreover, Pd-Cu2O/CF displayed long-term stability after ten cycle tests.