Unlocking direct H2O2 production from Nanosecond Pulsed Microwave Plasma Activation of Water

Hydrogen peroxide is the preferred green oxidant reagent since it decomposes only into water and oxygen. It has been demonstrated that plasma-based synthesis of H2O2 is influenced by plasma-water interactions, but the factors involved in the reaction mechanisms and synthesis are still a matter of investigation1,2. In this work, we directly use water in combination with argon plasma to produce H2O2 by means of a microwave plasma reactor. The reactor (Figure 1) consists of a coaxial torch based on microwaves modulated with nanosecond pulsations, which would allow a better control of the temperature3. Among different system configuration tests, the direct quenching of the plasma zone allowed the highest H2O2 concentrations up to 14 mM. The differences of reactive species observed by OES gave a hint of reaction pathways for the H2O2 formation.