Electrocatalytic nitrate reduction to ammonia by a triethanolamine Cu(II) complex

Abstract Herein, a trinuclear coper(II) complex [Cu3 II(H2L1)2(HCOO)4], (1), stabilized by triethanolamine, H3L1, is isolated and characterized by various spectroscopic techniques and through single crystal X-ray structure. In the complex 1, cooper(II) ions are in distorted octahedral coordination environment where two H3L1 ligands and four formates are present to hold this tri-nuclear copper assembly. The complex 1 depicts as an efficient catalyst to produce ammonia (NH3) through electrocatalytic nitrate reduction (eNO3RR) in a 0.2 M acetate buffer of pH 3, following a pseudo-first-order reaction kinetics producing 83% Faradaic Efficiency (FE%) of NH3 at −0.3 V vs. RHE with a yield rate of 21.56 μmol h−1 cm−2 at −0.5 V vs. RHE by suppressing the competitive HER.