Pure and Alloyed Copper-Based Nanoparticles Supported on Activated Carbon: Synthesis and Electrocatalytic Application in the Reduction of Nitrobenzene

A series of Cu-CuxO, Pt-Cu alloy, and Pt nanoparticles supported on inexpensive activated carbon with large surface area were developed as electrocatalysts for the reduction of nitrobenzene. This reaction can produce useful chemicals with the potential to cogenerate electricity if applied in a fuel cell. Both the nature of the metal employed and of the carbon material used as support play an important role in determining the performance of the electrocatalysts. Cu-based materials display lower onset potentials for the reduction of nitrobenzene, whereas the features of the activated carbon influence the stability of the electrocatalysts. The most promising electrocatalyst consisted of highly dispersed and very small Cu-CuxO nanoparticles (similar to 4 nm) supported on Norit activated carbon, which were prepared using H-2 as reductant. A chronoamperometric test in acidic ethanolic medium gave good conversion of nitrobenzene over this electrocatalyst, with azoxybenzene as the major product.