Characterization and evaluation of catalytic dechlorination activity of Pd/Fe bimetallic nanoparticles

Two kinds of Pd/Fe nanoparticles (NPs) (k-Pd/Fe NPs and p-Pd/Fe NPs) were prepared by using an aqueous solution of potassium hexachloropalladate and an ethanol solution of palladium acetate as palladization solution, respectively, through the chemical precipitation method, followed by drying in an oven under vacuum, and characterized systematically in terms of morphology (SEM), Pd loading (EDS), surface composition (XRF), specific surface area (BET), particle size (TEM), and crystal structure (XRD). Batch experiments were conducted to evaluate the catalytic dechlorination activity of the prepared Pd/Fe NPs. Evidence observed suggests that the activities of various kinds of particles used for dechlorination of chlorinated methanes including carbon tetrachloride (CT), chloroform (CF), and dichloromethane (DCM) followed the order p-Pd/Fe NPs > Fe NPs > k-Pd/Fe NPs > Micro-Fe (commercial microscale iron powder). This order was found to be dependent on the size, surface area, degree of Pd dispersion, and purity extent of metal particles. These results may provide better understanding of the effects of preparing and drying methods on the catalytic dechlorination activity of Pd/Fe NPs.