Carbon material coated nickel nanoparticle catalyst as well as preparation method and application thereof

Abstract

The invention discloses a carbon material coated nickel nanoparticle catalyst as well as a preparation method and application thereof. The carbon material coated nickel nanoparticle catalyst is prepared according to the following steps of: (1) weighing and pouring nickel salt and an organic ligand into an alcohol solvent for dissolving, and stirring at 0-50 DEG C for 3-24 hours to obtain a mixed solution; (2) dropwise adding alkali liquor into the mixed solution in batches, and adjusting the pH value of the solution in three stages; (3) sealing the slurry obtained in the step (2), placing the sealed slurry on a vibration platform, crystallizing, precipitating, aging, filtering, washing, and carrying out vacuum drying to obtain a metal organic framework precursor; and (4) roasting the precursor to obtain the carbon material coated nickel nanoparticle catalyst. The invention provides an application of the catalyst in the catalytic hydrogenation synthesis of halogenated aniline from halogenated nitrobenzene. According to the preparation method disclosed by the invention, the morphology of the precursor is effectively controlled on the basis of improving the metal utilization rate, so that the catalyst with a specific micro-structure is obtained, and the product selectivity can be effectively improved.

Description

technical field [0001] The invention belongs to the field of catalyst preparation technology and application, and relates to a carbon material-coated nickel nanoparticle catalyst and a preparation method and application thereof. Background technique [0002] Nickel nanoparticles have great application value in catalysis, lithium batteries, sensors and other fields. As a catalyst, nanoscale nickel particles have better catalytic activity than bulk or flake, but due to the high surface energy, nanoscale nickel particles are easy to agglomerate and limit its advantages. When exposed to the air, the metal nanoparticles are easily oxidized into metal oxides, and a layer of carbon material wrapped around the metal nanoparticles can prevent the metal nanoparticles from being oxidized. In addition to the characteristics of non-toxicity, high thermal stability and low price, the carbon layer-coated metal structure also has the characteristics of graphene. Its rich internal pore stru...

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Problems solved by technology

Tang et al [RSC Advances, 2017, 7(3):1531-1539] take terephthalic acid as coordination, nickel nitrate as nickel source, N,N-dimethylformamide as solvent, and react in an autoclave Prepare Ni-MOF precursor, and further prepare carbon-coated nickel catalyst through high-temperature nickel carbide source. This material also shows good selectivity in the hydrogenation reaction of aromatic nitro compounds such as p-chloronitrobenzene, but The thicker carbon layer leads to poor activity, and there are obvious pores that can be entered by reactant molecules, and metal nickel can be completely leached in an acidic environment

Although the above materials have shown good activity and selectivity in the reaction of halonitrobenzene to haloaniline, they cannot be applied to acidic environment systems, and it is easy to dechlorinate p-chloroaniline during the reaction process, reducing the risk of product quality. The hydrogen chloride produced at the same time will seriously corrode the equipment

In addition, the metal utilization rate and carbon coating degree of metal nickel prepared into carbon-coated catalysts have not been reported.

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