Abstract

Electrocatalytic hydrodechlorination (ECH) based on Pd-modified Ni foam electrodes offers a sustainable approach for decontaminating halogenated chlorinated organics, but the synthesis of Pd/Ni foam is always poorly controlled. In this work, with clofibric acid (emerging as a typical pharmaceutical) as a probe contaminant, we show that the ECH performance of Pd/Ni foam is highly dependent on the impregnation time during its preparation. During preparation, the dissolved Ni²⁺ can combine with aqueous OH^– to form in situ Ni(OH)₂ coatings on Pd/Ni foam. By prolonging the impregnation time, continuous deposition of Ni(OH)₂ gradually increases the anti-corrosive property and the electrochemically active surface area of the electrode. However, such covered Ni(OH)₂ coatings promote the interfacial charge transfer resistance and hinder the atomic H* adsorption by Pd, which is detrimental to ECH. This work provides a novel strategy for the synthesis of Pd/Ni foam electrodes with an enhanced ECH property for electroreductive remediation of chlorinated pharmaceutical compounds.