Liquid-phase hydrodechlorination of polychloroaromatic compounds in the presence of Pd-promoted nickel catalysts

Abstract

AbsWa~Liquid phase hydrodechlorination of chlorobenzene, 1,2,4-trichlorobe~ene, hexachlorobenzene, polychlorinated biphenyls in the ethanol-containing solution, on Me*/C (where Me* -Pd, Ni or bimetallic Ni-Pd; C -carbon material "Sibunit") with I-I2 have been studied at 20-700C and Pn2-1-50 attn. Pd and Pd-promoted Ni catalysts exhibit the highest activity. Kinetic studies show hydrodechlorination of these compounds to be a consecutive reaction, which under the conditions described may produce less chlorinated compounds.

Complete hydrodechlorination of chlorobenzene and its derivatives over supported nickel catalysts under liquid phase conditions

“…Transition metal catalysts, such as Ni, NiMo on g-alumina, silica or carbon composite [14][15][16][17][18][19][20][21] required high temperature (>473 K) or high hydrogen pressure (2 MPa) [14,15] to reach significant activity in the gas phase dechlorination process. For example, parasubstituted chlorobenzenes with amino-, hydroxyl-, chloro-, methyl-and trifluoromethyl were dechlorinated over Ni/g-Al 2 O 3 [19] in the gas phase at 523 K. Little literature is reported for liquid phase hydrodechlorination of chlorinated aromatics on Ni based catalysts so far, unless Pd is added into Ni catalysts [22,23].…”

Liquid-phase hydrodechlorination of chlorinated benzenes over active carbon supported nickel catalysts under mild conditions

“…Little literature is reported for liquid phase HDC of chlorinated aromatics on Ni based catalysts under mild conditions so far, unless Pd is added into Ni catalysts [20,21].…”

A Highly Active Pd on Ni–B Bimetallic Catalyst for Liquid-Phase Hydrodechlorination of 4-Chlorophenol Under Mild Conditions

“…Interpretation to this behavior is that Ni assembled high concentration of H 2 and reactants on the surface of the catalyst and Pd could frequently activate H 2 molecule to active hydrogen. The synergistic effect between Pd and Ni facilitated the catalyst with better activity and resistance to poisoning [37].…”