Properties Of Iron/Nitrogen Doped Carbon Catalysts And Catalytic Reduction Of Nitroarenes

Aromatic amine is an industrially valuable raw material,which has been widely used as the intermediate for many synthetic drugs and surfactants.Therefore,selective catalytic reduction of nitroarenes to corresponding arylamine is considered as one of the most important and challenging tasks in the synthesis of organic chemistry.Transition metal-supported or nonmetallic atom-doped catalysts can be used to substitute noble metals for selective catalytic hydrogenation of nitroarenes,due to their abundant earth storage,low price,high specific surface area and thermochemical stability of active components.Therefore,it is particularly important to design and develop transition metal or nonmetallic atom-based multi-porous nanomaterials with high catalytic activity and stable recycling.This paper mainly utilize N₂H₄·H₂O as the hydrogen source to explore the chemical effect of selective hydrogenation of nitroarenes under different catalyst system.The optimum catalyst preparation conditions were selected and the best catalytic performance of the reaction conditions was inspected.The comprehensive factors affecting the catalytic activity and selectivity were analyzed through the characterization parameters of morphological structure of catalyst.In addition,the wide applicability of the optimal catalyst in nitroarenes was discussed,and repeated tests were carried out to investigate the stability of catalyst.The work is mainly divided into two parts:The first part:Using one-step pyrolysis of bean pulp to prepare the porous carbon materials with abundant nitrogen content（RNC,6.5 wt%）,by KOH activation can get the high specific surface area of 711.9 m²/g.And explains in detail the in situ synthesis of rich nitrogen species can lead to ortho carbon charge delocalization and generate more defect sites,forming metal-like properties so as to improve the rate of reduction of hydrogenation activity.The final reaction results show that chloronitrobenzene was completely transformed at 5 h without dechlorination.The advantage of RNC catalyst was that it had better chemical selectivity than noble metal catalyst and lower reaction temperature than similar nonmetallic catalyst.The second part:Porous organic polymers（POP）formed by ferrocene formaldehyde and p-phenylenediamine simple thermal polymerization,and then nitrogen-containing porous carbon materials supported by magneticγ-Fe₂O₃ NPs（γ-Fe₂O₃/NPC）was prepared by carbonization in an inert atmosphere.γ-Fe₂O₃/NPC catalyst achieves bifunctional catalytic hydrogenation through the synergistic action between nitrogen and iron atoms,the stable doping of high content（34.5 wt%）γ-Fe₂O₃ NPs can be realized.The results showed that the catalyst had a conversion rate of 99.8%and selectivity of nearly 100%when the reaction time reached 80 min,even reused many times,still can maintain the stability of catalytic activity and high selectivity.