Investigation of amino-anthraquinones for the Oxygen Reduction Reaction to generate H2O2 in situ in an electrochemical reactor

• Grant number: 24/10645-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2025
• End date: December 31, 2026
• Field of knowledge: Engineering - Sanitary Engineering - Water Supply and Wastewater Treatment
• Principal Investigator: Marcos Roberto de Vasconcelos Lanza
• Grantee: Beatriz Tavoloni Marin
• 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

Abstract

Electrochemical technology allows the in situ generation of H2O2 from the 2-electron oxygen reduction reaction (2e- RRO), using carbonaceous materials as catalysts. In order to reduce the overpotential required for the 2e- RRO, the use of organic modifiers on the carbon, such as the class of anthraquinone amines, can bring advantages to the system, since the amino group are electron donors for the ring. Therefore, the presence of the modifiers generates a synergistic effect with the carbon, shifting the potential to positive values and consequently reducing the energy expenditure of the system. Based on this, this work aims to study the influence of different anthraquinone amines (varying the position of the substituent group) as modifiers of the Printex L6 carbon for 2e- RRO. To this end, electrocatalytic studies will be carried out, such as cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy and chronoamperometry, and photo-electrocatalytic studies, mainly to evaluate possible photocurrent. The studies will be carried out on materials modified with different mass proportions of each organic modifier. Structural characterization analyses such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle, and surface area by N2 physisorption of the modified carbon will also be carried out. In addition, the work aims to exemplify a mechanism via 2e- in order to understand how the substituent group interferes in the oxidant's electrogeneration process. Finally, the best conditions will be used for the electrogeneration of H2O2 at the gas diffusion electrode (GDE) in a bench-top cell and in an electrochemical flow reactor, in order to show the applicability of the electrode in scales close to industrial.