Non-Thermal Plasma (NTP) for continuous H2O2 production from water and oxygen

Conventional methods for hydrogen peroxide (H₂O₂) synthesis, such as heterogeneous catalytic processes, require hydrogen (H₂) and oxygen (O₂) as feedstocks, along with expensive noble metals and organic solvents. These methods are energy-intensive and hazardous. In contrast, non-thermal plasma (NTP) generated within a dielectric barrier discharge (DBD) coaxial reactor provides 1 to 10 eV energy, sufficient to even drive thermodynamically unfavorable reactions by breaking molecular bonds. This study investigates the direct synthesis of aqueous H₂O₂ by passing oxygen through varying flow rates in a non-thermal plasma reactor. The outlet gas from the plasma reactor is then bubbled into water, facilitating H₂O₂ production. This method relies solely on water, oxygen, gas, and electricity, offering an environmentally friendly alternative to traditional processes.

This study also explores the role of a water–ethanol solution in enhancing product yield by approximately 10 times in the continuous production of concentrated aqueous hydrogen peroxide (H₂O₂). Experiments were initially conducted without catalysts, and the impact of various gas flow rates, plasma power, and residence time on conversion efficiency was examined. Electron Spin Resonance (ESR) studies indicate that oxygen radicals play a crucial role in the selective production of H₂O₂. Our findings present a proof-of-concept for utilizing low-cost aluminum electrodes in a dielectric barrier discharge (DBD) reactor, relying solely on electricity, water, and dioxygen for the generation of H₂O₂. This ongoing process ensures continuous improvement and provides the scalability needed to achieve high technology readiness levels.