Atom-dispersed copper and nano-palladium in the boron-carbon-nitrogen matric cooperate to realize the efficient purification of nitrate wastewater and the electrochemical synthesis of ammonia.

Electrochemical nitrate reduction reaction (NIRR) driven by sustainable energy is not only expected to realize the green production of ammonia under ambient conditions, but also a promising way to purify nitrate wastewater. The ammonia yield rate and Faradaic efficiency of NIRR catalyzed by Pd10Cu/BCN constructed with structural constraints and pre-embedded reducing agent strategies were as high as 102,153 μg h-1 mgcat.-1 and 91.47%, respectively. Pd10Cu/BCN can remove nearly 100% of 50 mg L-1 NO3- without NO2- residue within 10 h, and the realization of this effect does not require the participation of any chloride. Control experiments and DFT calculations explain the efficient operation mechanism of NIRR on Pd10Cu/BCN, where the Pd and CuN4 sites play the role of synergistic catalysis. Compared with the reported literature, Pd10Cu/BCN with good biocompatibility has become an outstanding representative of NIRR catalyst, which provides an alternative way for the green production of ammonia and the purification of nitrate wastewater.