Kinetics and Mechanism of Dechlorination of o-Chlorophenol by Nanoscale Pd／Fe

IntroductionTherehasbeenagrowinginterestintheuseofzero valentironforthetreatmentofchlorinatedor ganiccompounds(COCs)inwaterandgroundwater .Thestudieshavebeenfocusedonsuchcompoundsascarbontetrachloride ,trichloroethene ,pesticidesandtherelatedcompounds1— 7] .Whenironisincontactwithalessreductivemetalsuchaspalladiumwhosecomplexhasbeenusedtohydrogenatenitroben zene8] ,themetalcouplecanformgalvaniccells .ThisledtothediscoveryofaPd/Febimetalliccomplexofwhichpalladiumservesasacatalystandironasa…

Kinetics and Mechanism of Dechlorination of o-Chlorophenol by Nanoscale Pd/Fe

Nanoscale Pd/Fe bimetallic particles were synthesized with an efficient method to dechlorinate o-chlorophenol. The nanoscale Pd/Fe particles were determined by transmission electron microscopy and BET specific surface area analysis. Most of the particles are in the size range of 20-100 nm. The BET specific surface area of synthesized nanoscale Pd/Fe particles is 12.4 m2/g. In contrast, a commercially available fine iron powder(<100 mesh) has a specific surface area of 0.49 m2/g. Batch studies demonstrated that the nanoscale particles can effectively dechlorinate o-chlorophenol. The dechlorination reaction takes place on the surface of synthesized nanoscale Pd/Fe bimetallic particles in a pseudo-first order reaction. The surface-area-normalized rate coefficients(kSA) are comparable to those reported in the literature for chlorinated ethenes. The observed reaction rate constants(kobs) are dominated by the mass fraction of Pd and the mass concentration of the nanoscale Pd/Fe particles.