Electrochemical Dechlorination of Trichloroethylene by Manganese Phthalocyanine: Performance and Mechanisms

Trichloroethylene (TCE) is one of the most abundant persistent organic pollutant in subsurface environment. TCE can be reduced electrochemically, but the extremely negative applied potential limits the application of this technology. Manganese phthalocyanine (MnPc) catalyst was used for the electrochemical reductive dechlorination of TCE. The results show that MnPc can be reduced by electrons attachment at −-0.21 V, −-1.22 V and −-1.77 V, respectively. With the decrease of applied potential from −-0.3 V to −-1.8 V, the transformation from TCE to dichloroethylene (DCE) efficiency increased from 19.9% to 41.8% after 5 hours of reaction. Although the electron transfer ability was enhanced with applied potential decreasing, the intensive HER caused the electron selectivity decreased when MnPc attached more electrons. MnPc catalyze the electrochemical reduction of TCE, which has potential application on the remediation of TCE-contaminated groundwater.