On the promoting effect by quaternary ammonium salts in the multiphase hydrodechlorination with hydrogen gas on Raney nickel catalyst

Hydrodechlorination of 1,3,5-trichlorobenzene with hydrogen gas on Raney nickel catalyst in the biphasic system composed of isooctane, aqueous KOH, and a quaternary ammonium compound as a promoter at 70 °C and atmospheric pressure was studied. The promoter increased the rate of reaction above two orders of magnitude. Several quaternary chloride salts were studied, such as Aliquat 336, trioctylmethylammonium, tridodecylmethylammonium, cetyltrimethylammonium, tetrabutylammonium and tetraethylammonium. The relationship of the reaction rate with adsorption, micelle formation, and the structural properties of the promoter are discussed.