Preparation method and application of oxidization modified carbon nanotube-loaded double-metal copper and magnesium co-doped nickel-based multi-metal catalyst

Abstract

The invention discloses a preparation method and application of an oxidization modified carbon nanotube-loaded double-metal copper and magnesium co-doped nickel-based multi-metal catalyst. A multi-wall carbon nanotube loaded multi-metal nickel-based catalyst subjected to hydrogen peroxide oxidization is utilized and Cu is introduced so that the reduction energy of a Ni precursor can be effectively reduced and the dispersion of Ni nanoparticles on the surface of the carbon nanotube is accelerated; meanwhile, more Ni<0+> can be formed under the synergistic effect of Cu and Ni. Mg is introduced so that a large quantity of alkaline sites are provided for the surface of the catalyst; meanwhile, a NiO-MgO co-solution is formed so that excessive hydrogenation of reactants is easy to inhibit and excessive byproducts are not formed. Oxidization treatment of the carbon nanotube can be used for further accelerating a strong mutual effect of the carbon tube and active components, so that the hydrogenation activity of the catalyst is greatly improved; the catalyst is used for adiponitrile hydrogenation reaction and relatively high conversion ratio and total selectivity of products can be obtained.

Description

technical field [0001] The invention relates to the field of material preparation, in particular to a preparation method and application of an oxidation-modified carbon nanotube-supported bimetallic copper-magnesium co-doped nickel-based multimetal catalyst. Background technique [0002] The hydrogenation of adiponitrile mainly produces 6-aminocapronitrile and hexamethylenediamine, wherein 6-aminocapronitrile is a very critical step in the new process of butadiene / adiponitrile synthesis of caprolactam. In the butadiene / adiponitrile process, the research on the hydrocyanation process of butadiene based on nickel phosphine homogeneous catalyst in the first step has been relatively mature. DuPont was the first to use this method to produce adiponitrile. Through the two-step reaction of butadiene hydrogenation and then cyanation, the yield of adiponitrile can reach 95.6%. For the research on the process of cyclization of 6-aminocapronitrile to caprolactam in the third step, com...

AI Technical Summary

Problems solved by technology

However, the recovery rate of the catalyst is low, and a large amount of alkali is required to suppress the formation of by-products

[0009] In summary, the above catalysts for the hydrogenation of adiponitrile all have problems to a certain extent, or are difficult to separate and lead to recycling difficulties; or use a large amount of precious metals As an active component, it causes resource waste and high cost; or the activity of the catalyst is not very high; or the reaction conditions are very demanding

For example, Raney type catalysts, metal rhodium-based catalysts and other precious metal catalysts have high cost, low recycling rate, and are easy to deactivate. At the same time, due to the large amount of alkaline water (ammonia) used, the equipment is severely corroded, the amount of wastewater treatment is large, and the reaction pressure is very high. High, further increasing the production cost, the economic benefit is not significant; another example is the amorphous alloy catalyst, the hydrogen consumption in the gas phase method is extremely high, and the reaction temperature is high, resulting in higher production costs and more complicated processes