2025/05/22 by Trench, Aline B., Moura, João Paulo C., Antonin, Vanessa S. +3 · 1 citation
#Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2505.16871
The use of the oxygen reduction reaction (ORR) for in-situ production of H2O2 is an attractive alternative to replace the methods based on anthraquinone oxidation. This study investigates the modification of Vulcan XC72 carbon with Ce-doped Nb2O5 in different molar proportions and its application as electrocatalysts in the ORR. One performed the characterization of the electrocatalysts using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy. Subsequently, the electrocatalysts were analyzed for the ORR and the Nb2O5 doped with 0.5% Ce showing the highest electrocatalytic response. This electrocatalyst was also employed as a gas diffusion electrode and exhibited more significant H2O2 production at all potentials than the Vulcan XC72 carbon modified solely with Nb2O5. At the applied potentials of -1.3 V and -1.9 V, it produced 105% and 86% more H2O2, respectively, than the Vulcan XC72 carbon modified only with Nb2O5. These results can be attributed to the doping of Nb2O5 with 0.5% Ce, which induces local distortions in the crystal lattice of Nb2O5 due to the difference in ionic radius between Nb5+ and Ce3+, which combined with increased hydrophilicity and wetting properties, may have facilitated electron transfer and O2 transport, favoring the ORR.