High-efficiency Electrochemical Dechlorination Using an Atomically Dispersed Co Catalyst in an Aqueous Phase

Electrochemical hydrodechlorination is a promising method for the degradation of disinfection by-products (DBPs) under mild conditions. In this study, we synthesized atomically dispersed Co on N-doped graphene (A-Co-NG) as an efficient electrocatalyst and studied its hydrodechlorination activity and reaction mechanism using trichloroacetic acid (TCAA) as a model DBP. The galvanostatic electrolysis experiments showed that the A-Co-NG catalyst had a higher dechlorination activity than that of commercial Pd/C. Using A-Co-NG, chloroacetic acids (CAAs) were completely dechlorinated to acetic acid at pH values of 3, 7, and 11. The dechlorination of CAAs by A-Co-NG follows a direct dechlorination mechanism. The first electron transfer (ET) and C-Cl bond breaking processes proceed sequentially, and the first ET step is the rate-determining step for the dechlorination of TCAA.