Mechanism and Regioselectivity of the Electrochemical Reduction in Polychlorobiphenyls (PCBs): Kinetic Analysis for the Successive Reduction of Chlorines from Dichlorobiphenyls

Autor: Azhagumuthu Muthukrishnan, Vadim P. Boyarskiy, Irina A. Boyarskaya, M.V. Sangaranarayanan
Rok vydání: 2011
Předmět:
Transfer coefficient
Bulk electrolysis
Potential sweep voltammetry
Rate constants
Kinetics
Analytical chemistry
Electrochemical reductions
Experimental data
Theoretical calculations
Electrochemistry
Bond reductions
Polychlorobiphenyls
Electron transfer
Regioselectivity
Reaction rate constant
Polychlorinated biphenyls
Butler-Volmer kinetics
Marcus-Hush
Regio-selective
Quantum chemical calculations
Chemical analysis
Physical and Theoretical Chemistry
Voltammetry
Bond-breaking
Intrinsic barriers
Chemistry
Electrolytic reduction
Driving forces
Kinetic analysis
Bond length
Potential energy
Analysis of the product
Surfaces
Coatings and Films
Electronic
Optical and Magnetic Materials
Heterogeneous rate constant
General Energy
Dichlorobiphenyls
Physical chemistry
Electron-transfer step
Chlorine
Quantum chemistry
Zdroj: The Journal of Physical Chemistry C. 116:655-664
ISSN: 1932-7455
1932-7447
DOI: 10.1021/jp2066474
Popis: The regioselective electrochemical reduction of three different dichlorobiphenyls is analyzed using quantum chemical calculations and convolution potential sweep voltammetry. The heterogeneous rate constants of C-Cl bond reductions of each of the dichlorobiphenyls are estimated. The mechanism of the electrochemical reduction is confirmed by estimating the intrinsic barrier from the experimental data on transfer coefficients as well as theoretical calculations involving bond length and potential energy diagrams. The reductions follow the Marcus-Hush quadratic activation driving force relation barring the meta-Cl of the 3,4-dichlorobiphenyl which obeys Butler-Volmer kinetics. The first electron transfer step is rapid in comparison with the bond-breaking, implying the stepwise reduction for all the dichlorobiphenyls studied here. High performance liquid chromotagraphy analysis of the products of the bulk electrolysis confirms the order of the reduction in dichlorobiphenyls viz. the ease of reduction follows the order ortho-Cl > para-Cl > meta-Cl. � 2011 American Chemical Society.
Databáze: OpenAIRE
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