Application of gas diffusion electrodes modified with manganese (III) oxide in flow reactors for the production of high value-added products from glycerol

• Grant number: 25/08726-8
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: September 01, 2025
• End date: August 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
• Supervisor: Manuel Andres Rodrigo Rodrigo
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Universidad de Castilla-La Mancha, Ciudad Real (UCLM), Spain
• Associated to the scholarship: 24/10972-4 - Synthesis and characterization of new electrocatalysts for the electrogeneration of hydrogen peroxide and their technological applications, BP.PD

Abstract

Glycerol, a byproduct generated by the biodiesel industry, is a multifunctional compound with the potential to be converted into more than 2,000 fine chemical products in its raw form. However, due to its low purity and the presence of several impurities (such as methanol, soaps, catalysts, salts and organic matter) a significant portion of the glycerol obtained during biodiesel synthesis is sold at low cost, which limits its industrial and economic value. In view of this scenario, several treatment alternatives have been proposed for the valorization of this byproduct, focusing on its conversion into higher value-added compounds. Among these, the in situ electrochemical generation of hydrogen peroxide (H2O2) has emerged as an effective and sustainable strategy within advanced electrochemical processes. Additionally, the synergistic combination of electrolysis and electrodialysis enables the efficient production of carboxylates, adding value to the generated by-products. Thus, the integration of different electrochemical technologies is of great relevance. Moreover, offers significant advantages over conventional treatments, including higher efficiency in contaminant removal, improved recovery of by-products, and greater operational reliability. This BEPE project proposes the application of gas diffusion electrodes (GDEs), made of carbon black and modified with metals recovered from alkaline battery wastes (manganese (III) oxide (Mn2O3)) and previously characterized electrochemically in Brazil, regarding the general postdoctoral project, for wastewater treatment envisaging the generation of value-added products. The electrogeneration of H2O2, degradation efficiency, volumetric flow rate, current density, pH, and energy consumption of the process will be evaluated. Additionally, electrodialysis will be integrated into the system, along with anionic membrane, to enhance ionic selectivity and improve the accumulation of generated carboxylic acids. The proposal aligns with the principles of the circular economy and the Sustainable Development Goals- SDG (7,12, 13). Therefore, we propose integrated electrochemical systems as an innovative, sustainable, and economically viable solution to contemporary environmental challenges.