ScholarWorks@성균관대학교

초록

Plasma-based hydrogen peroxide (H2O2) synthesis uses only water and electricity, and has therefore gained attention for its environmentally benign nature compared to the existing anthraquinone process. However, such plasma-based routes face limitations in achieving high H2O2 concentrations. Here, we investigated dielectric barrier discharge (DBD) plasma with aerosolized water to produce high-concentration H2O2 in the aqueous phase (H2O2aq). The concentration of H2O2aq was quantified by peroxotitanic acid spectrophotometry, while the plasma dissipated power and the ozone concentration were measured using the Lissajous method and optical absorption spectroscopy (OAS), respectively. The concentration of H2O2aq increased linearly as the input power rose from 20 to 40 W, and reached a maximum of 4.42 mM. To elucidate the mechanism, a zero-dimensional (0-D) kinetic model was developed to trace fluid elements passing through the discharge region. The simulation calculated the mass transfer between the gas and aqueous phases based on diffusion, considering the geometric characteristics of the aerosols. The simulation results showed good agreement with the experimental H2O2aq concentrations. The main production pathways of H2O2aq were the dissolution of gas-phase H2O2 and the recombination reaction between liquid-phase hydroxyl (OHaq) and hydroperoxyl (HO2aq) radicals. As the power increased, the main production pathway shifted from OHaq recombination reaction to gas-phase H2O2 dissolution, which is consistent with the fact that increased OH promotes the production of gaseous H2O2. In addition, simulations with and without aerosols confirmed that aerosols effectively capture gaseous H2O2 and increase H2O2aq production by lowering gaseous OH and HO2 concentrations, thereby suppressing their destruction reactions.

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