Facile fabrication of γ-Fe2O3-nanoparticle modified N-doped porous carbon materials for the efficient hydrogenation of nitroaromatic compounds

Abstract

Novel γ-Fe₂O₃-nanoparticle (NP) modified N-doped porous carbon materials (γ-Fe₂O₃/mCN) were prepared by one-pot pyrolysis of a mixture of melamine, polyacrylonitrile, and FeCl₃·6H₂O at different temperatures. At a pyrolysis temperature of 900 °C, γ-Fe₂O₃/mCN-900-20 exhibited a high surface area and a N content of 8.47%, caused by the complete pyrolysis of melamine and polyacrylonitrile at 900 °C. The obtained material γ-Fe₂O₃/mCN-900-20 was used as a cost-effective catalyst for the hydrogenation of nitrobenzene using N₂H₄·H₂O as the reductant under mild reaction conditions. As compared to other catalysts (e.g., noble metal catalysts), γ-Fe₂O₃/mCN-900-20 exhibited high catalytic performance (TOF of 311.83 h⁻¹, selectivity of 100%). During the catalytic hydrogenation of nitroaromatic compounds with reducible groups, e.g., alcoholic hydroxyl, halogen, and amino groups, an excellent selectivity close to 100% was achieved. Moreover, because the active sites of γ-Fe₂O₃ has magnetic performance, the catalyst can be easily recovered using a magnet, and reused at least four runs without an obvious activity decrease. Hence, the easily prepared, cost-effective and reusable γ-Fe₂O₃/mCN catalyst fabricated in this study demonstrates potential for applications in selective reduction of aromatic nitro compounds.