Catalytic hydrogenation catalyst as well as preparation thereof and application thereof to selective hydrogenation reaction of aromatic nitro compound

Abstract

The invention discloses a catalytic hydrogenation catalyst as well as a preparation thereof and application thereof to the selective hydrogenation reaction of an aromatic nitro compound. The catalystcomprises an activated carbon carrier coated with a modified coating layer and metal quantum dots loaded on the carrier; metal is palladium, and the particle size range of each of the metal quantum dots is between 4 mm and 7 nm; activated carbon is irregular or molded granular activated carbon, and the size is not greater than 1 cm; a pore structure of the activated carbon coated with the modifiedcoating layer is dominated by a mesopore, the micro-pore ratio is reduced to below 10 percent, and the composition materials of the modified coating layer are titanium dioxide, silicon dioxide and titanium silicate. The invention discloses the application of the catalytic hydrogenation catalyst to the reaction of aromatic hydroxylamine shown as a selective catalytic hydrogenation synthesis formula II of the aromatic nitro compound shown as a formula I; the catalytic hydrogenation catalyst has the characteristics of no additive requirement, high conversion rate, good selectivity, high hydrogenation reaction rate, good stability, long catalyst service life and hydrogen recycling.

Description

(1) Technical field

[0001] The invention relates to a catalytic hydrogenation catalyst and its preparation and application, in particular to the application of the catalyst in catalytic selective hydrogenation of aromatic nitro compounds. (2) Technical background

[0002] Aromatic hydroxylamine (also known as aromatic hydroxylamine) is an important intermediate in organic synthesis, and is widely used in polymerization inhibitors, antioxidants, pesticides, medicines, cosmetics, etc. Synthesis, such as the use of Bamberger rearrangement to transform into p-aminophenol, an important intermediate of substituted aromatics such as medicines, dyes, and spices; BASF has also successfully developed pyraclostrobin (BAS 500F) fungicide products with aromatic hydroxylamine as the key intermediate. However, during the reduction process of aromatic nitro compounds, the intermediate aromatic hydroxylamine will be rapidly converted into the corresponding amine, which is not only difficult ...

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