Cobalt-based nanocatalysts for green oxidation and hydrogenation processes.

This protocol describes the preparation of cobalt-based nanocatalysts and their applications in environmentally benign redox processes for fine chemical synthesis. The catalytically active material consists of nanoscale Co3O4 particles surrounded by nitrogen-doped graphene layers (NGrs), which have been prepared by pyrolysis of phenanthroline-ligated cobalt acetate on carbon. The resulting materials have been found to be excellent catalysts for the activation of both molecular oxygen and hydrogen; in all tested reactions, water was the only by-product. By applying these catalysts, green oxidations of alcohols and hydrogenation of nitroarenes for the synthesis of nitriles, esters and amines are demonstrated. The overall time required for catalyst preparation and for redox reactions is 35 h and 10-30 h, respectively.