Tetrakis-(4-sulfonatophenyl)porphyrin cobalt was identified as a highly-active reductive dechlorination catalyst for chlorinated ethylenes. Through batch reactor kinetic studies, degradation of chlorinated ethylenes proceeded in a step-wise fashion with the sequential replacement of Cl by H. For perchloroethylene (PCE) and trichloroethylene (TCE), the dechlorination products were quantified and the C2 mass was accounted for. Degradation of the chlorinated ethylenes was found to be first-order in substrate. Dechlorination trials with increasing catalyst concentration showed a linearly increasing pseudo first-order rate constant which yielded rate laws for PCE and TCE degradation that are first-order in catalyst. The dechlorination activity of this catalyst was compared to that of another water-soluble cobalt porphyrin under the same reaction conditions and found to be comparable for PCE and TCE.
Bibliographical noteFunding Information:
This work was funded by the generous support of Tooma Undergraduate Research Fellowships and Undergraduate Research Programs at Pepperdine University. The authors would like to thank David Green for his technical support with respect to instrumentation and many helpful conversations. We would also like to thank Daphne Green, Paul Pestano, and Allison Zorn for their laboratory management support.
- Chlorinated ethylenes
- Cobalt porphyrin
- Kinetic studies
- Reductive dechlorination