Stable H2O2 electrosynthesis at industrially-relevant currents by a membrane-based electrode with high oxygen accessibility.

Electrosynthesis of hydrogen peroxide (H 2 O 2) presents a sustainable alternative to the anthraquinone process, while the transition to applying this process at industrial-relevant currents remains a significant challenge. Most studies tried to solve it by catalysts modulations, whereas we found that the accessibility to the gaseous O 2 , might be the crux of this matter. Herein, we developed a series of membrane-based gas diffusion electrodes (Mem-GDEs) with varied O 2 accessibility. Their endurable currents were found to be well correlated with the O 2 mass transferability. By constructing high O 2 -accessible triphasic interfaces, Mem-GDE achieved a recorded current density, 1.4 A cm−2, with the current efficiency higher than 80.6 %. It was also verified for the first time that the insufficient O 2 triggered a severe flooding problem and thus further deteriorate the O 2 mass transfer. This study highlights the importance of O 2 accessibility and provides new insights into triphasic interfaces construction for realizing industrial-used H 2 O 2 -generated electrodes. [Display omitted] • Mem-GDE with high O2 accessibility was fabricated by employing a PTFE membrane. • The Mem-GDE has great stability in producing H2O2 at industrial current densities. • Severe flooding can be triggered by the deficiency of O2 supply. • The Mem-GDE has great potential for long-term application for contaminant removal. [ABSTRACT FROM AUTHOR]