Kinetics of hydrogenation of nitrobenzene, 4-nitrotuluene, 4-nitroaniline and 2-chloro-4-nitroaniline on supported palladium catalyst

Krasnov, A.I.; Latypova, A.R.; Lefedova, O.V.; Sharonov, N.Y.; Efremov, E.V.; Filippov, D.V.

doi:doi:10.6060/tcct.20165904.5332

Krasnov, A.I.; Latypova, A.R.; Lefedova, O.V.; Sharonov, N.Y.; Efremov, E.V.; Filippov, D.V. (2016)

Kinetics of hydrogenation of nitrobenzene, 4-nitrotuluene, 4-nitroaniline and 2-chloro-4-nitroaniline on supported palladium catalyst

A study of the kinetics of liquid phase hydrogenation of nitrobenzene, 4-nitrotoluene, 4-nitroaniline and 2-chloro-4-nitroaniline on supported palladium catalyst in aqueous solutions of 2-propanol of different composition was carried out. The influence of the substituent on the value of the total amount of hydrogen absorbed during the reaction and the kinetics of the hydrogenation of substituted nitrobenzenes was discussed. It was found out that the reaction selectivity to 2-chloro-1,4-phenylenediamine decreases due to by-reaction dehalogenation. The degree of dehalogenation depends on the composition of solvent and may be approximately estimated by the values of the absorbed hydrogen volume during the reaction. Also, the presence of the donor-acceptor substituents is capable of exerting influence on the reaction rate of hydrogenation of the nitro compound.

nitrobenzene

4-nitrotoluene (NT)

4-nitroaniline (NA)

2-chloro-4-nitroaniline (CNA)

2-chloro-4-phenylenediamine (CPhDA)

hydrogen

supported palladium catalyst

adsorption

aqueous solution of 2-propanol

acetic acid

sodium hydroxide

reaction rate