Facile and template-free synthesis of porous carbon modified with FeOx for transfer hydrogenation of nitroarenes

Abstract

It is necessary to develop cost-effective heterogeneous catalysts for the selective reduction of nitroarenes owing to the wide application of the product anilines. At present, porous carbon combined with transition metals is attracting increasing attention due to the inherent merits of the two components. Nevertheless, tedious and time-consuming procedures are generally needed to fabricate the catalysts, during which additional templates or activators are commonly required. In this contribution, a facile and convenient template-free method was developed for the synthesis of porous carbon modified with FeOx nanoparticles. The in situ formed sodium-containing species was responsible for activation of the carbon matrix. XRD and XPS measurements indicated that the FeOx was composed of Fe₃O₄ and metallic Fe, where the latter was deeply embedded in the material. The synthesis temperature had a notable effect on the porous structure and production at 700 °C generated the material with the highest specific surface area. The optimized catalyst not only showed good performance in the transfer hydrogenation of nitroarenes, but also exhibited a relatively high stability. Further study demonstrated that both Fe₃O₄ and the carbon matrix play important roles in the reaction, with the former being the more critical agent.