Synthesis and characterization of new electrocatalysts for the electrogeneration of hydrogen peroxide and their technological applications

• Grant number: 24/10972-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: August 01, 2024
• End date: July 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Marcos Roberto de Vasconcelos Lanza
• Grantee: Raira Souza de Santana Castro
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 22/12895-1 - Advanced processes for the degradation of emerging pollutants: catalytic materials, electroanalytical sensors and scientific dissemination, AP.TEM
• Associated scholarship(s): 25/08726-8 - Application of gas diffusion electrodes modified with manganese (III) oxide in flow reactors for the production of high value-added products from glycerol, BE.EP.PD

Abstract

Among advanced oxidation processes (AOP), Fenton chemistry-based methods stand out as widely employed techniques for removing persistent contaminants in wastewater. These processes leverage the hydroxyl radical (OH), derived from the Fenton reaction between hydrogen peroxide (H2O2) generated in situ or externally added and Fe2+ ions for compound degradation. To ensure efficiency and viability in the Fenton process, innovative, low-cost materials with good replicability must serve as efficient catalysts to electrogenerate H2O2.This project aims to synthesize carbon-based gas diffusion electrodes (EDG) modified with manganese and zinc dioxide nanostructures, using waste from discarded batteries, for the degradation of antidepressant drugs. The reuse of these batteries emerges as an efficient tactic to boost progress in sustainable chemistry The oxides will be prepared for the first time by the hydrothermal synthesis method assisted by the muffle furnace with metal oxides supported on carbon, aim to enhance catalytic activity and produce homogeneous, stable films for in-situ hydrogen peroxide production. Additionally, DSA® and BDD-type anodes will be applied and compared to ensure greater efficiency in hydrogen peroxide generation.Characterization of the synthesized electrocatalysts will employ energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques and electrochemical techniques using RRDE system. These materials will be utilized in oxidative processes based on Fenton chemistry for the degradation of fluoxetine and venlafaxine. Electrosynthesis of H2O2 will be monitored via UV/Vis spectroscopy, while the efficiency of compound degradation processes will be assessed using high-performance liquid chromatography (HPLC) and total organic carbon content (TOC) techniques. To evaluate the performance of materials on a large scale, a flow reactor equipped with new optimized cathode and anode materials will be employed.