Reduction of nitric oxide at a platinum cathode in an acidic solution

• Published in: Electrochimica acta 1977, Vol.22 (1), p.27-30
• Main Authors: Janssen, L.J.J., Pieterse, M.M.J., Barendrecht, E.
• Format: Article
• Language: English
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/0013-4686(77)85048-2

The reduction of nitric oxide at a platinum electrode in 4 M H 2SO 4 was investigated by the measurement of potential/current relations and by the determination of the current efficiencies for the hydroxylamine, nitrous oxide, ammonia, hydrazine and hydrogen formation at fixed potentials in the potential range from 0 to −400 mV vs sce. The potential/current curve for the reduction of nitric oxide has two waves, of which the limiting currents depend strongly on the potential and the time of the pretreatment of the electrode and on the direction of the potential change during the measurements. In the potential range of the first wave ( viz ϵ > −30 mV) nitric oxide is reduced only to nitrous oxide. In the whole potential range of the second wave ( viz from −50 to −250 mV) nitric oxide is reduced to hydroxylamine, ammonia and nitrous oxide. Formation of hydrazine has not been detected. From the literature and from the relations of the current efficiencies a possible mechanism is proposed for the reduction of nitric oxide.