Banca de QUALIFICAÇÃO: JOÃO PAULO CARVALHO MOURA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : JOÃO PAULO CARVALHO MOURA
DATA : 16/04/2025
HORA: 14:00
LOCAL: Sala 306 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TÍTULO:
PÁGINAS: 44
RESUMO:

The oxygen reduction reaction (ORR) plays a crucial role in clean energy generation and the sustainable production of hydrogen peroxide (H₂O₂), being also essential for applications in advanced electrochemical oxidation processes. In these studies, WO₃/Vulcan XC-72 electrocatalysts were synthesized and characterized for ORR applications and the degradation of environmental pollutants. The influence of the WO₃/Vulcan XC-72 ratio and the electrolyte pH (acidic and alkaline media) was investigated, demonstrating that WO₃ with a monoclinic crystalline phase and nanoflower-like morphology improved surface properties by increasing hydrophilicity and the presence of oxygenated species. Electrochemical studies revealed that WO₃/C exhibited high selectivity for H₂O₂ electrogeneration in both media, reaching up to 916 mg L⁻¹ at 100 mA cm⁻², with an efficiency above 70% and lower energy consumption compared to pure Vulcan carbon. The synergistic effect between WO₃ and Vulcan XC-72 was theoretically confirmed, highlighting the contribution of functional oxygen acid species on the catalyst surface and the improvement in the ORR mechanism. Furthermore, the application of gas diffusion electrodes based on WO₃/C in the electro-Fenton (EF) process demonstrated high efficiency in ciprofloxacin (CIP) degradation, achieving approximately 70% removal within the first 30 minutes of reaction. However, limitations in iron(II) recovery reduced the EF efficiency over time. This barrier was overcome by the UV-assisted photoelectro-Fenton (PEF) process, enabling complete CIP degradation within 90 minutes. The total organic carbon mineralization was optimized using boron-doped diamond anodes, reaching up to 66% mineralization. Based on the experimental analysis of degradation byproducts, combined with computational calculations, two main degradation pathways were proposed: hydroxyl radical attack on the piperazine ring, with or without defluorination, and oxidation of the quinolone ring. The theoretical simulation of byproducts revealed that the electrocatalytic treatment significantly reduced the environmental impact of the treated wastewater, validating the proposed degradation mechanisms. These findings highlight WO₃/C electrocatalysts as promising materials for both H₂O₂ electrosynthesis and the efficient degradation of persistent pollutants, offering a sustainable approach to environmental remediation.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1544381 - MAURO COELHO DOS SANTOS
Membro Titular - Examinador(a) Interno ao Programa - 1544341 - WENDEL ANDRADE ALVES
Membro Titular - Examinador(a) Externo à Instituição - CHRISTIANE DE ARRUDA RODRIGUES - UNIFESP
Membro Suplente - Examinador(a) Externo à Instituição - MAURO BERTOTTI - USP