Reaction Conditions and Mechanism of Electrolytic Reduction of Nitrobenzene

[摘要] Electrochemical reduction of nitrobenzene (¥ÕNO2) and its derivatives on Pb electrode was studied by means of galvanostatic measurements and coulometric electrolysis in ethanol-water solvent. In acidic solutions phenylhydroxyl amine and aniline ethanol-water solvent. In acidic solutions phenylhydroxyl amine and aniline were produced while nitrosobenzene and coupled products such as azo-and hydrazobenzene were produced in basic solutions. Nitrosobenzene (¥ÕNO) was not found to be an intermediate in the reduction reactions of ¥ÕNO2 in acidic solutions. No direct coupling between ¥ÕNO and ¥ÕNHOH was observed to occur in the electrolyte solutions used. Mechanisms of the production of phenylhydroxylamine and nitrosobenzene are deduced from Tafel slope, pH dependence and reaction order with respect to nitrobenzene. Mechanism for the reduction of substituted nitrobenzenes seems to be identical to that of nitrobenzene.

[学科分类] 化学（综合）