The electrocatalytic behaviour of Pt and Cu nanoparticles supported on carbon nanotubes on the nitrobenzene reduction in ethanol

Journal article, 2013

In view of investigating the possibility of cogeneration of chemicals and electricity in a fuel cell typereactor, a suitable electrocatalyst and optimal reaction conditions have to be found. The nitrobenzenereduction was taken as the case study reaction for this investigation. In literature no suitable electro-catalyst has been found for this reaction. Pt and Cu nanoparticles, supported by multiple wall carbonnanotubes, were taken as electrocatalysts and ethanolic and acidic ethanolic environments were studiedas possible reaction media. The Cu nanoparticle catalyst displayed superior electrocatalytic behavioursince less overpotential is needed for the nitrobenzene reduction in both ethanolic and acidic ethanolicenvironment. The acidic ethanolic conditions were superior to the ethanolic conditions as less overpo-tential was required for the nitrobenzene reduction reaction and a higher conversion of nitrobenzene isobtained. In acidic ethanolic environment, a four-electron reduction is taking place, which was assigned tothe reduction of nitrobenzene into phenylhydroxylamine. This compound is re-oxidised into nitrosoben-zene when the solution comes into contact with oxygen, and the formed nitrosobenzene selectivelyreacts with another phenylhydroxylamine molecule, yielding azoxybenzene. The latter is an importantcompound in organic synthesis.