Enhanced electrocatalytic hydrodechlorination of 2,4-dichlorophenoxyacetic acid by a Pd-Co3O4/Ni foam electrode

A new Pd-Co3O4/Ni foam electrode was synthesized by a facile two-step method comprising co-electrodeposition and calcination. Compared with Ni foam-supported Pd electrodes obtained by electrodeposition or chemical deposition, the new Pd-Co3O4/Ni foam electrode exhibited greatly enhanced catalytic hydrodechlorination activity. The introduction of Co3O4 reduced the amount of Pd required. For the same degree of dechlorination of 2,4-D, only 25% of the Pd was required in the Pd-Co3O4/Ni foam electrode compared with the Ni foam electrode prepared by chemical deposition. Various characterizations indicated that Co3O4 on the surface of the Ni foam enhanced catalytic performance through accelerated generation of atomic H*. In addition, the good distribution of macropores, providing a larger specific surface area and lower electron transfer impedance, enabled more adsorption of atomic H-ads*.