Application of metal-free hydrogenation catalyst in catalyzing hydrogenation reaction of nitrobenzene and derivatives thereof

Abstract

The invention discloses application of a metal-free hydrogenation catalyst in catalyzing hydrogenation reaction of nitrobenzene and derivatives thereof. The metal-free hydrogenation catalyst is nitrogen-doped carbon nanotubes prepared by an impregnation process by using melamine as a nitrogen source, or nitrogen-doped carbon nanotubes prepared by an in-situ synthesis process by using ammonia gas as a nitrogen source; and the catalyst is applied to hydrogenation reaction of nitrobenzene and derivatives thereof. The nitrogen-doped carbon nanotubes used as the nitrobenzene hydrogenation catalyst do not support any metal active component, and can achieve the goal of hydrogenation catalysis only by using the nitrogen doping modification process. The whole reaction process avoids the use of noble metals, thereby saving the cost and avoiding environment pollution; and meanwhile, the catalyst can be recycled. The catalyst has the advantages of simple preparation method, low production cost, favorable hydrogenation effect, controllable reaction and environment friendliness, can not cause secondary pollution to the environment, and can be widely used in various hydrogenation reactions.

Description

technical field [0001] The invention relates to the fields of material preparation and chemical engineering, in particular to the application of a metal-free hydrogenation catalyst in catalyzing the hydrogenation reaction of nitrobenzene and its derivatives. Background technique [0002] Aniline is an important organic chemical intermediate and solvent, which is widely used and has a large market demand. At present, the production process of aniline mainly adopts nitrobenzene iron powder reduction method, phenol ammoniation method and nitrobenzene catalytic hydrogenation method. Among them, the catalytic hydrogenation method of nitrobenzene has the characteristics of low reaction temperature and few by-products, accounting for about 85% of the total production capacity of aniline. [0003] At present, most of the liquid-phase hydrogenation reactions of nitrobenzene use noble metal catalysts. Although the noble metal catalysts have high activity, the cost is also high and it...

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Problems solved by technology

Although this method can reduce the loss of the catalyst to a certain extent, its active components are still noble metals, and the cost of the catalyst is very high. The invention also uses base metal nickel as the catalytically active metal, but the loss of the active metal is unavoidable in the reaction. polluted the environment

[0006] In summary, the preparation cost of noble metal catalysts is high, and metal dissolution and loss are prone to occur during the reaction, which not only leads to a continuous decline in activity, but also causes environmental pollution.

Although non-precious metals greatly reduce the cost of catalyst preparation, the catalyst process and steps are complicated, which is not conducive to engineering operations, and the amount of metal used is large. At the same time, the phenomenon of metal loss is inevitable, causing environmental pollution.

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