Inhibition of In Situ Formed Ni(OH)₂ on a Pd/Ni Foam Cathode for Efficient Electrocatalytic Hydrodechlorination of Clofibric Acid

Electrocatalytic hydrodechlorination (ECH) based on Pd-modifiedNi foam electrodes offers a sustainable approach for decontaminatinghalogenated chlorinated organics, but the synthesis of Pd/Ni foamis always poorly controlled. In this work, with clofibric acid (emergingas a typical pharmaceutical) as a probe contaminant, we show thatthe ECH performance of Pd/Ni foam is highly dependent on the impregnationtime during its preparation. During preparation, the dissolved Ni2+ can combine with aqueous OH- to form insitu Ni(OH)(2) coatings on Pd/Ni foam. By prolonging theimpregnation time, continuous deposition of Ni(OH)(2) graduallyincreases the anti-corrosive property and the electrochemically activesurface area of the electrode. However, such covered Ni(OH)(2) coatings promote the interfacial charge transfer resistance andhinder the atomic H* adsorption by Pd, which is detrimental to ECH.This work provides a novel strategy for the synthesis of Pd/Ni foamelectrodes with an enhanced ECH property for electroreductive remediationof chlorinated pharmaceutical compounds.