Construction Of Iron Oxide-Based Catalysts And Its Application In Reduction Of Nitroarenes To Aromatic Amines

Aromatic amines,as important amines,are the basic raw materials of the chemical industry and are used on a wide scale.Most businesses employ nitroaromatic reduction to produce aromatic amines.Although the catalysts employed in the linked processes all have strong reduction performance,they suffer from substantial pollution,expensive costs,and storage safety issues.Iron oxide-based catalysts are readily available,affordable in cost,and environmentally friendly.Iron oxide-based catalysts,on the other hand,are difficult to produce and have low catalytic efficiency,making industrialization problematic.To that end,we have significantly improved the catalytic activity of iron oxide-based catalysts by introducing synergistic catalytic components through doping（using hydrazine hydrate as a hydrogen source）and constructing a physical hybrid catalytic system（using hydrogen as a hydrogen source）,respectively,to achieve the reduction of aniline from nitrobenzene catalyzed by equal equivalents of hydrazine hydrate at room temperature and hydrogen at atmospheric pressure.Furthermore,the mechanism of catalytic activity was thoroughly studied by integrating physical and chemical parameter characterisation,mechanistic tests,and DFT simulations.The main contents are as follows:1.The co-precipitation method was used to successfully prepare single-atomic-level Zr-regulated α-Fe₂O₃,resulting in the formation of a special O-bridge structure capable of achieving complete transfer hydrogenation of nitroaromatics under mild reaction and iso-chemistry ratio hydration,and a special direct reduction route without nitroso-nitrobenzene was proposed by detailed mechanistic experiments and DFT calculations.2.Under moderate circumstances,a novel α-Fe₂O₃+Cu₂O physically mixed catalytic system was developed to catalyze the hydrogenation of nitroaromatics to arylamines.Under the same circumstances,the conversion of single α-Fe₂O₃ inactive and Cu₂O was 8%,while the conversion of co-precipitated Fe-Cu composite oxide was 30%.Characterization and mechanistic investigations revealed that the capacity of α-Fe₂O₃+Cu₂O to activate hydrogen was significantly greater than that of single α-Fe₂O₃ and Cu₂O,and α-Fe₂O₃ played a significant role in substrate adsorption activation.