2025/05/20 by Moura, João Paulo C, Lucchetti, Lanna EB, Fernandes, Caio M +5
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.2505.13800
The oxygen reduction reaction (ORR) plays a pivotal role in clean energy generation and sustainable chemical production, particularly in the synthesis of hydrogen peroxide (H\textsubscript2O\textsubscript2). In this study, WO\textsubscript3/Vulcan-XC72 electrocatalysts were synthesized and characterized for ORR applications, evaluating the WO\textsubscript3 to Vulcan-XC72 ratio and examining electrolyte pH effects across acidic and alkaline media. Structural characterization confirmed successful synthesis of monoclinic WO\textsubscript3 with nanoflower morphology, which enhanced surface hydrophilicity and oxygen functional groups. Electrochemical tests demonstrated WO\textsubscript3/C's superior H\textsubscript2O\textsubscript2 selectivity compared to pure Vulcan-XC72 in both media, revealing a pH-dependent ORR mechanism. Using WO\textsubscript3/C gas diffusion electrodes (GDEs), we achieved 862,mg,L\textsuperscript-1 H\textsubscript2O\textsubscript2 accumulation after 120,min at 100,mA,cm\textsuperscript-2. The enhanced performance stems from increased oxygen functional groups, improved hydrophilicity, and WO\textsubscript3 nanoflower synergistic effects, as supported by theoretical calculations, establishing WO\textsubscript3/Vulcan as a promising catalyst for electrochemical H\textsubscript2O\textsubscript2 production.