Kinetics of Tetrachloroethylene-Reductive Dechlorination Catalyzed by Vitamin B sub(12)

Tetrachloroethylene reduction was examined in a vitamin B sub(12)/trivalent titanium-catalyzed system using a relatively simple kinetic model, which is outlined. Batch systems were prepared in duplicate in an anaerobic chamber. Results showed that vitamin B sub(12) quickly converted tetrachloroethylene to trichloroethylene, which was further reduced via hydrogenolysis and reductive beta elimination. The main 1,2-dichloroethylene isomer formed was cis-1,2-dichloroethylene, which was derived from chloroacetylene that was produced via reductive beta elimination of trichloroethylene. Ethene, the final end product, was produced primarily via reduction of acetylene. The kinetic model was able to reproduce the general features exhibited in the experimental data.