Nitrous oxide (dinitrogen oxide), N20, is used extensively in anesthesia and as an electron scavenger in laboratory processes. It also may be involved in the chemistry of air pollution.
In the first context there is evidence 1 that in an oxygen-monitoring cell containing 30~o KOH, the lead anodes are attacked and the cell distended after repeated passage of N20 +0 2 mixtures. Nitrogen gas is much less soluble in the cell electrolyte than nitrous oxide and has been detected above the liquid by mass spectrometry. Although N20 is a potentially powerful oxidizing agent, most of its oxidation reactions only occur at elevated temperatures. Recent work 2 substantiates this conclusion: films of metallic Fe and Ni are oxidized above 30Β°C, W and Pd are attacked only slowly and Pb is unaffected up to 250Β°C. Nitrogen and metal oxide are the reaction products.
The extent of previous electrochemical investigations of N20 is limited. Eletskii et al. 3 reported an increased current at a lead electrode when N20 replaced hydrogen in 0.1 M KF solution but no current change at a mercury electrode. Hydrazine was obtained from N2 O reduction in (NH4)2SO4; the yield varied from zero on platinum to 15~o on mercury electrodes 4. Dutta and Landolt 5 observed relatively little electroactivity of N20 on Pt in 4 M H2SO4 at -0.2 V vs. SCE. The oxidation and reduction of both NO and HNO2 at platinum s'6 and mercury 7 electrodes have been studied in some detail.
The present paper summarizes the results of a cyclic voltammetric study of N20 at a platinum electrode in alkaline media, as well as some observations for NO, NO2, Pb02, and 5202in tee same system. EXPERIMENTAL AR grade NaHCO 3, standard pH 10 buffer solution, AR grade KOH, and AR grade K2S20 8 were obtained from Mallinckrodt Chemical Works, reagent grade KNO2 from Allied Chemical, N20 from Matheson (98~o) or Union Carbide (99~) and NO (98.5~o) from Union Carbide. Buffer solutions of pH 8.3 and pH 14.0 were prepared from NaHCO3 (0.5 M) and KOH (1 M) with CO2-free water.