In situ-synthesized amorphous Pd/N-C microspheres derived from shrimp shells as a three-dimensional electrocatalyst for hydrodechlorination of diclofenac

Abstract Developing electrocatalysts with low cost, high abundance and high activity is the greatest challenge facing electrocatalytic hydrodechlorination technology. The Nitrogen-carbon microsphere (N-CM) material was synthesized in situ through a simple hydrothermal carbonization method using shrimp shells as C and N sources. N-CM with a rough surface was obtained at a carbonization temperature of 650 ℃, which has a large surface area of 90.14 m2/g and rich N content. Subsequently, the Pd catalyst was successfully modified on the N-CM surface by chemical reduction for electrocatalytic hydrodechlorination of Diclofenac (DCF). The successful loading of Pd and amorphous Pd structures was confirmed by a series of systematic characterizations. The amorphous Pd/N-CM-650 catalyst exhibits a fast electron transfer rate and electrocatalytic activity. Notably, at a Pd loading of 1.27 wt%, a cathode potential of −1.2 V and 20 mg of Pd/N-CM-650 particle electrodes, 25 mg/L DCF reached a dechlorination efficiency of 95% within 150 min with a current efficiency of 34.4%. Combined with the qualitative analysis and toxicity evaluation of hydrodechlorination products, the toxicity of DCF can be effectively reduced. Additionally, the cycle experiments also displayed excellent stability of the Pd/N-CM-650 electrode.