Using ZrNb and ZrMo oxide nanoparticles as catalytic activity boosters supported on Printex L6 carbon for H2O2 production

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2023-09, Vol.34 (9), p.104108, Article 104108
• Main Authors: Trevelin, L.C., Valim, R.B., Lourenço, J.C., De Siervo, A., Rocha, R.S., Lanza, M.R.V.
• Format: Article
• Language: English
• Subjects: Hydrogen peroxide; Molybdenum oxide; Niobium oxide; Oxygen reduction reaction; Zirconium oxide
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2023.104108

[Display omitted] •The 5% ZrNb/PL6C material yielded a H2O2 selectivity of 84.3%.•The 5% ZrNb/PL6C had a 200 mV shift to less negative potential, compared to PL6C.•The 1% ZrMo/PL6C material yielded a H2O2 selectivity of 77%.•The 1% ZrMo/PL6C had a 400 mV shift to less negative potential, compared to PL6C. Oxygen reduction reaction (ORR) is an important reaction which is widely applied in advanced oxidative processes (AOP) through the in-situ electrogeneration of hydrogen peroxide. Oxygen gas can either be reduced to hydrogen peroxide via two-electron pathway or be converted to water in a competitive way via four-electron pathway. In this study, we report the effective enhancement of H2O2 generation in K2SO4 0.1 mol/L (pH 2) through the application of Printex L6 carbon (PL6C) modified with zirconium/niobium (ZrNb) and zirconium/molybdenum (ZrMo) oxides compared to unmodified PL6C. The proposed catalysts were prepared by the polymeric precursors synthesis method (on carbon). The catalysts were analyzed by X-ray fluorescence (FRX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), and were electrochemically characterised by cyclic voltammetry (CV) and hydrodynamic linear sweep voltammetry (LSV). The electroactivity of ZrNb/PL6C and ZrMo/PL6C oxides was analyzed in the ratio of 50/50 w/w. The results obtained from the electrochemical characterisations of the electrodes showed that the application of 5% ZrNb/PL6C and 1% ZrMo/PL6C yielded H2O2 selectivity of 84.3 and 77%, respectively, compared to 84.3% recorded for the unmodified PL6C. Also, based on the application of a determined current density, 5% ZrNb/PL6C and 1% ZrMo/PL6C recorded a potential shift of 200 and 400 mV to less negative potentials, respectively, compared to the unmodified PL6C, which implies in less energy consumption. The results obtained from the morphological and surface characterisations of the materials pointed to a practically homogeneous distribution of ZrO2, Nb2O5, and MoO3 with particle size of ca. 5 nm on the PL6C surface compared to the unmodified PL6C which exhibited particle size of ca. 30–50 nm.