Catalyst for selective hydrogenation reaction of aromatic nitrocompound and preparation method of catalyst

Abstract

The invention relates to a catalyst for selective hydrogenation reaction of an aromatic nitrocompound and a preparation method of the catalyst. The catalyst consists of a catalyst carrier and active metal coated with carbon, wherein the catalyst carrier includes a carbon-base carrier, SiO2, TiO2 or Al2O3; the active metal is selected from Co, Fe, Ni or Cu and other poor and noble metals. The catalyst is prepared by adopting a Pechini type sol-gel process which comprises the steps of dispersing an active metal precursor to water containing a coordination compound, adding a polyhydric alcohol solution and a macromolecule auxiliary, then adding the carrier, stirring for dispersion, carrying out hydrothermal reaction, separating out solid on the lower layer, and calcining in the inert atmosphere to obtain the catalyst in which carbon coats the active metal. Compared with the prior art, the catalyst can realize the hydrogenation reaction of a substituted aromatic nitrocompound in the mild condition; substrate conversion rate and production selectivity are high; the catalyst has recyclable economy and good application prospect.

Description

technical field [0001] The invention relates to the field of catalyst preparation, in particular to a catalyst for selective hydrogenation of aromatic nitro compounds and a preparation method thereof. Background technique [0002] Functionalized aromatic amines are a class of important chemical raw materials transformed from substituted aromatic nitro compounds, which are widely used in the synthesis of pharmaceuticals, dyes, polymers, pesticides, spices and surfactants, biomass fuels, etc. Chemical Products. The hydrogenation of nitro compounds to prepare aromatic amines is a common catalytic hydrogenation reaction, which can be realized by many commercial catalysts, such as Pd / C, Pt / C or RaneyNi, etc., and these catalysts are relatively selective in the hydrogenation reaction of substituted nitro compounds. Low. Therefore, the key to successfully realize the selective hydrogenation of substituted aromatic nitro compounds to prepare functional aromatic amines lies in the ...

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Problems solved by technology

[0003] In recent years, there have been quite a few reports on the selective hydrogenation of substituted aromatic amines. The heterogeneous catalysts reported in the literature are mainly divided into two categories: 1) noble metal catalysts, such as supported gold (WO2007116111-A1; Journal of Catalysis, 265 (2009) , 19; GreenChem., 14(2012), 3164) and platinum catalysts (WO2009071727; CN201210468132.8; JournalofCatalysis, 321(2015), 7), etc. These noble metal catalysts are costly, need to add additives to regulate selectivity, and the product There are problems such as metal residues in the catalyst, which greatly limits the practical application of this type of catalyst.

2) Base metal catalysts, literature (Chem.Com., 48(2012), 7982) utilizes citric acid-stabilized iron nanoparticle catalysts to achieve selective hydrogenation of substituted nitro compounds in water. Since the iron catalyst does not use a carrier, Therefore, it is difficult to realize the reuse of catalyst

Although both catalysts have high selectivity, expensive organic nitrogen-containing ligands (1,10-phenanthroline) are used in the catalyst preparation process, which undoubtedly increases the cost of catalyst preparation.

In addition, this preparation method is only suitable for carbon-based supports, and other supports have low activity

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