# Overcoming Thermal Degradation during Continuous Conversion of Water into Hydrogen Peroxide in a Flexible Plasma Reactor

## TL;DR

A flexible plasma reactor efficiently produces hydrogen peroxide from water while avoiding thermal degradation.

## Contribution

A continuous process using plasma and water to produce hydrogen peroxide with minimal thermal degradation is developed.

## Key findings

- Hydrogen peroxide concentrations up to 0.17 wt% were achieved with high energy efficiency.
- Thermal degradation was minimized through plasma zone quenching.
- Hydrogen peroxide formation is influenced by microwave pulse parameters and inversely related to water flow rate.

## Abstract

By control of the nanosecond pulsation, energy input,
and flow,
it is possible to achieve commercial-level hydrogen peroxide (H2O2) concentrations using only water and plasma
in a continuous process while minimizing thermal degradation. Time-resolved
ultrafast Optical Emission Spectroscopy was employed to observe the
formation of reactive species, shedding light on the underlying mechanisms.
This study also found that thermal degradation has a critical role,
which was effectively managed through quenching of the plasma zone.
A parametric scan of pulse duration and pulse repetition frequency
of the microwave power showed a significant influence on H2O2 formation, whereby the mean power also plays an important
role. Additionally, the H2O2 concentration was
found to be inversely proportional to the water flow rate. A maximum
concentration of 0.17 wt % was achieved with 1.2 g/kWh based on the
absorbed power at a flow rate of 0.2 mL/min. This plasma reactor technology
shows promise for further development as a decentralized solution
for the green chemical synthesis of H2O2.