(31a) Electrocatalytic Degradation of 4-Chlorophenol Using Combustion Synthesized Magnesium Ferrite Catalyst

Industrial wastewater, many times, contains phenol and phenol related compounds that are difficult to remove by traditional treatment methods. Many of these compounds are toxic in nature and are difficult to remove by traditional biological treatment methods. These compounds must be treated before being discharged. Herein, we explore the electrochemical route for treatment of 4-chlorphenol in presence of a active catalysts. Magnesium oxide, iron oxide and their mixed oxides were synthesized for this purpose using solution combustion technique. These catalysts were prepared from their precursors in nitrate form in presence of an oxidizing agent, causing ignition and subsequent combustion resulting in highly porous oxides with large surface area suitable for catalytic applications. Electrolytes with concentrations of 25, 50, and 75 mg/L of 4-CP were prepared to evaluate the catalytic performance under varying experimental conditions. The electrochemical performance of the catalysts was evaluated to assess their performance using cyclic voltammetry and linear sweep voltammetry. The results indicate a change in the behavior of the catalyst depending on the concentration of the 4-CP in the solution. FeO exhibited a higher current density at lower concentrations of 4-CP, while the MgFe₂O₄ composite catalyst demonstrated a superior performance at higher concentrations. FeO alone showed a preference for water splitting compared to 4-CP degradation, whereas MgFe₂O₄ showed better performance for 4-CP degradation. This study presents a convenient method to study electrochemical degradation of 4-CP based on observed current density in a rotating disc electrode (RDE) and shows a fast screening of the catalysts for 4-chlorophenol degradation using electrochemical testing.

Keywords: Magnesium ferrite; 4-chlorophenol (4-CP) degradation; Rotating disc electrode; Solution combustion synthesis

Acknowledgement: This publication was made possible by the NPRP grant (NPRP13S-0109-200029) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of author(s).