Copper-doped nitrogen-modified carbon material as well as application thereof and reaction method for preparing symmetric/asymmetric azobenzenes by oxidative coupling of aromatic amines

Abstract

The invention belongs to the field of catalytic materials, and particularly relates to a copper-doped nitrogen-modified carbon material. The copper-doped nitrogen-modified carbon material is preparedby the following steps: (1) dissolving citric acid and magnesium nitrate into water, and performing drying at 80-150 DEG C to obtain a yellow solid, wherein the yellow solid is used as a precursor; and (2) uniformly grinding and mixing the precursor obtained in the step (1), melamine and a copper salt, performing a reaction for 0.5-3 h under the protection of nitrogen and a temperature of 700-1000DEG C, performing cooling to room temperature, and performing uniform grinding to obtain the Cu-N-C catalyst, that is, the copper-doped nitrogen-modified carbon material. The material provided by theinvention exhibits good catalytic ability and stronger substrate compatibility in the process of oxidizing aromatic amines by oxygen to synthesize symmetric and asymmetric azobenzenes; and the copper-doped nitrogen-modified carbon material as well as a method for synthesizing the material and a catalytic application of the material provided by the invention have important significance.

Description

technical field [0001] The invention belongs to the field of catalytic materials, in particular to a copper-doped nitrogen-modified carbon material, its application and a reaction method for oxidative coupling of aromatic amines into azobenzene. Background technique [0002] Oxidation of aromatic amines as an important method is an important way to synthesize aromatic nitro, azobenzene oxide, azobenzene, and nitrosobenzene compounds. After decades of development, a variety of methods for the selective synthesis of azobenzene by oxidation of aromatic amines have been proposed, and a variety of metal or metalloid reagents are used as catalysts and oxidants. For example: AgO, Ag 2 O, Pb(OAc) 4 、AgCO 3 , MnO 2 , BaMnO 4 、Ce(OH) 3 o 2 H, RuCl 3 , MnTPPCl-NaIO 4 、Mn(TPP)OAc-Bu 4 NHSO 5 , HgO-I 2 、NaBO 3 -Acetic acid; O 2 -KO-tBu, H 2 o 2 , O 2 -CuCl, Galvinoxyl-K 3 Fe(CN) 6 -KOH, ZrO 2 , Gd (ш) complex. Exist some problems in these methods: (1), heavy metal, p...

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Problems solved by technology

There are some problems in these methods: (1), heavy metal, precious metal are used in a large number, and environment is caused certain pollution and is unfavorable for expanding application

(2), the reaction conditions are complicated, and benzene is often used as a solvent, which is unhealthy for the environment and human body

(3), stoichiometric or large excess use of oxidizing agents, the reduction products of some oxidizing agents will cause environmental pollution

(4), selectivity is poor, and the yield of product is lower

(5) There are few reports on cross-coupling synthesis of unsymmetrical azobenzene

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