Understanding reductive dechlorination of trichloroethene on boron-doped diamond film electrodes

Dhananjay Mishra, Zhaohui Liao, James Farrell

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

This research investigated reduction of trichloroethylene (TCE) at boron-doped diamond (BDD) film cathodes using a rotating disk electrode reactor. Rates of TCE reduction were determined as functions of the electrode potential and TCE concentration over a temperature range between 2 and 32°C. Reduction of TCE resulted in production of acetate and chloride ions with no detectable intermediate products. At a current density of 15 mA/cm2 and concentrations below 0.75 mM, reaction rates were first order with respectto TCE concentration, with surface area normalized rate constants 2 orders of magnitude greater than those for iron electrodes. Density functional theory (DFT) simulations were used to evaluate activation barriers for reduction by direct electron transfer, and for reaction with four functional groups commonly found on BDD surfaces. The DFT calculated activation barrier for direct electron transfer was more than 4 times greater than the experimentally measured value of 22 kJ/mol. In contrast the DFT activation barrier for reaction at a deprotonated hydroxyl site on a tertiary carbon atom (≡C-0-) of 24 kJ/mol was in close agreement with the experimental value. Both experiments and quantum mechanical simulations support a TCE reduction mechanism that involves chemically adsorbed intermediates.

Original languageEnglish (US)
Pages (from-to)9344-9349
Number of pages6
JournalEnvironmental Science and Technology
Volume42
Issue number24
DOIs
StatePublished - Dec 15 2008

Fingerprint

Trichloroethylene
Dechlorination
Boron
Diamond films
dechlorination
trichloroethylene
boron
diamond
electrode
Electrodes
Density functional theory
Chemical activation
electron
Diamond
Electrons
Rotating disks
Hydroxyl Radical
reaction rate
Functional groups
functional group

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry

Cite this

Understanding reductive dechlorination of trichloroethene on boron-doped diamond film electrodes. / Mishra, Dhananjay; Liao, Zhaohui; Farrell, James.

In: Environmental Science and Technology, Vol. 42, No. 24, 15.12.2008, p. 9344-9349.

Research output: Contribution to journalArticle

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