The influence of ion effects on the Pd-catalyzed hydrodechlorination of 4-chlorophenol in aqueous solutions

The aim of this work was to study the influence of ions on the hydrodechlorination of 4-chlorophenol in water over 5% Pd/C catalyst. It was found that the presence of some ions such as Na(+), K(+), NH(4)(+), Ca(2)(+), Mg(2)(+), Cl , Br ,CO(3)(2-), HCO(3)(-), SO(4)(2-) and NO(3)(-) etc., did not show negative effects on catalyst activity in the hydrogenation process of 4-chlorophenol in aqueous solutions. But, when Fe(2+), Fe(3+), Cu(2+), Zn(2+), Ni(2+) and Pb(2+) etc., were present in water, they could reduce the activity of Pd/C and even led Pd/C to deactivate. (C) 2009 Elsevier B.V. All rights reserved.