Cathodic Reduction of Nitrobenzene on the Packed-bed Copper Electrode

Abstract

Abstract An application of a packed-bed copper electrode to the formation of aniline by the cathodic reduction of nitrobenzene was investigated. As the particles for the packed-bed, spherical particles of an anion exchange resin chemically plated with copper were successfully used. Though the current efficiency for the aniline formation on the packed-bed electrode in a batch cell decreased with continuing electrolysis, the efficiency was improved by the electrolysis under a flowing electrolyte and became very high, i.e., near 100%. This is due to the removal of the accumulated products on the electrode surface by the flowing electrolyte. The effective depth of the bed electrode on which the nitrobenzene reacted cathodically was also determined from the measurement of the potential profile in a packed-bed electrode: the result was about 3 mm. This low value of the effective depth is ascribed to the low conductivity of the electrolyte and to the high electronic conductivity of the packed-bed. This may be improved by using bed particles of lower electronic conductivity and a higher cell capacity may be expected.