Liquid-phase hydrodechlorination of chlorobenzene by molecular hydrogen: The influence of reaction medium on process efficiency

Simagina, Valentina I.; Tayban, Elena S.; Grayfer, Ekaterina D.; Gentsler, Anna G.; Komova, Oksana V.; Netskina, Olga V.

doi:10.1351/PAC-CON-08-10-12

Pure Appl. Chem., 2009, Vol. 81, No. 11, pp. 2107-2114

http://dx.doi.org/10.1351/PAC-CON-08-10-12

Published online 2009-10-26

Liquid-phase hydrodechlorination of chlorobenzene by molecular hydrogen: The influence of reaction medium on process efficiency

Valentina I. Simagina*, Elena S. Tayban, Ekaterina D. Grayfer, Anna G. Gentsler, Oksana V. Komova and Olga V. Netskina

Boreskov Institute of Catalysis, Pr. Akademika Lavrentieva 5, Novosibirsk 630090, Russia

Abstract: Catalytic hydrodechlorination (HDCl) of chlorobenzene was carried out in a two-phase aqueous–organic solvent system and a single-phase solvent composed of saturated KOH solution in a secondary alcohol over Pd-based catalysts at 50 °C and atmospheric pressure of H₂. It was shown that an aqueous–organic solvent system containing propan-2-ol and aqueous KOH increases catalyst activity by promoting mass transfer of the formed chloride ions to water phase that prevents catalyst deactivation. It is inferred that propan-2-ol favors hydrogen activation during the HDCl process. Use of the Pd catalysts based on hydrophobic carbon support enables chlorobenzene HDCl to proceed in a two-phase solvent at a satisfactory rate, even in the absence of phase-transfer catalysts.