Interfacial Engineering in Cu/Co 4 N Heterostructure toward Ammonia Production from Nitrate Reduction

Electrocatalytic nitrate reduction reaction (NO 3 RR) offers a bright pathway for ammonia (NH 3 ) production and protection of the environment. Most NO 3 RR catalysts still suffer from insufficient surface active hydrogen (H ads ). In the research, a Cu/Co 4 N heterostructure is constructed in which the Cu acts as the adsorption for NO 3 – while the Co 4 N enhances the water dissociation to supply H ads for the consecutive NO 2 – -to-NH 3 pathway. Due to the synergistic effect, the Cu/Co 4 N heterostructure exhibits excellent performance for NO 3 RR in neutral electrolyte. At a potential of −0.6 V vs RHE (reversible hydrogen electrode), the Cu/Co 4 N heterostructure attained a Faradaic efficiency (FE) of 93% with an NH 3 production of 27.64 mg h –1 cm –2 . Benefiting from its outstanding NO 3 RR activity, a Zn-NO 3 – battery employing the Cu/Co 4 N heterostructure as the cathode achieved a maximum power density of 10.1 mW cm –2 . The study supplies valuable opinions in the tandem catalysis of heterostructure catalysts and offers an aspect for devising high-performance NO 3 RR catalysts, aiming to achieve effectual selectivity, sustainable NH 3 yield, and environmental contamination control.