title: Kinetic study of hydrodechlorination of chlorobiphenyl with polymer-stabilized palladium nanoparticles in supercritical carbon dioxide.
abstract: Hydrodechlorination of 4-chlorobiphenyl in supercritical fluid carbon dioxide (SF-CO(2)) catalyzed by palladium nanoparticles stabilized in high-density polyethylene beads proceeds by consecutive reactions to the final product bicyclohexyl. Each step of the reaction sequence, that is, 4-chlorobiphenyl --> biphenyl --> cyclohexylbenzene --> bicyclohexyl, follows pseudo-first-order kinetics. Arrhenius parameters of each reaction step were determined separately in SF-CO(2) by in situ absorption spectroscopy using a high-pressure fiber-optic cell. A simulation of product distributions using the first-order consecutive reaction equations was performed and compared with the experimental results obtained by GC/MS analysis of the 4-chlorobiphenyl reaction system. The differences are explained in terms of adsorption/desorption behavior of the intermediates on the catalytic metal surface with respect to the stereostructures of the molecules generated by a molecular mechanics method.
authors.affiliation: Department of Chemistry, University of Idaho, Moscow, Idaho 83844, USA.
authors.forename: Weisheng
authors.initials: W
authors.lastname: Liao
authors.forename: Horng-Bin
authors.initials: HB
authors.lastname: Pan
authors.forename: Hsin-Wang
authors.initials: HW
authors.lastname: Liu
authors.forename: Hsing-Jung
authors.initials: HJ
authors.lastname: Chen
authors.forename: Chien M
authors.initials: CM
authors.lastname: Wai