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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 2 O 2). In this study, WO 3 /Vulcan-XC72 electrocatalysts have been synthesized and characterized for ORR applications. We assessed the ratio of WO 3 to Vulcan-XC72 and investigated the impact of electrolytes pH (covering acidic and alkaline media) on the ORR process. The results revealed that WO 3 with a monoclinic crystalline phase and nanoflower-like morphology was successfully synthesized, and confirmed an improvement in surface properties, with an increase in hydrophilicity and superficial oxygenated species. Electrochemical studies showed that WO 3 /C was the most selective for H 2 O 2 electrogeneration, compared to pure Vulcan-XC72, in both acidic and alkaline media. These results indicate that the ORR on the WO 3 /C electrocatalyst surface has a pH-dependent mechanism. Using WO 3 /C GDEs, an accumulation of 862 mg L-1 of H 2 O 2 was achieved after 120 min of electrolysis at 100 mA cm-2. The higher selectivity of WO 3 /C could be related to the presence of more oxygen functional acid species on the catalyst surface and increased hydrophilicity compared to pure Vulcan, as well as a synergistic effect of the WO 3 nanoflowers in ORR, confirmed by theoretical calculations. The results reveal that WO 3 /Vulcan is a promising catalyst for H 2 O 2 electrogeneration via the ORR. [Display omitted] • Proposal of selective catalysts for the 2-electron ORR. • WO 3 nanoflowers and Vulcan XC72 carbon were studied in different pHs for ORR. • There was an improvement in surface properties, hydrophilicity, and oxygenated species. • WO 3 /Vulcan is a very promising catalyst for H 2 O 2 electrogeneration via the ORR. [ABSTRACT FROM AUTHOR]

[Display omitted] • First-time study of magnetic field-enhanced 2-electron oxygen reduction reaction. • Investigation of different cerium oxide nanostructures on carbon Vulcan XC72. • The magnetic field shows significant improvements to conventional electrocatalysis. • Best performance with 5 % CeO 2 /C nanocubes, enhancing H 2 O 2 selectivity. • Magnetic field correlation with Zeeman effect, Lorentz and Kelvin forces, and BMP. We investigated cerium oxide nanoparticles of various morphologies (nanosheets, nanocubes, and nanoparticles) supported on carbon Vulcan XC-72 for the two-electron oxygen reduction reaction (ORR). A continuous magnetic field (2000 Oe) was used for the first time in the literature. The best results were for 5 % (w/w) CeO 2 for all three different morphologies, more than doubling the ring current, enhancing the hydrogen peroxide selectivity from 51 % (Vulcan XC-72) to 84–89 %, and modifying the onset potential to lesser negative values. The presence of the magnetic field led to even higher ring currents with 5 % (w/w) CeO 2 , H 2 O 2 selectivity from 54 % (Vulcan XC-72) to 88–96 % and changing even more the onset potential. Those results were correlated with the Zeeman effect, the Lorentz force, generating magnetohydrodynamic effects, the Kelvin force, and the formation of Bound Magnetic Polarons. This pioneering research introduces an innovative approach, highlighting the potential of an external continuous magnetic field. [ABSTRACT FROM AUTHOR]