CO

Area of Science:

• Plasma chemistry and physics
• Renewable energy conversion
• Carbon capture and utilization (CCU)

Background:

• Power-to-chemical technologies aim to recycle carbon dioxide (CO2) and store energy in valuable chemical compounds.
• Plasma discharges, powered by renewable electricity, offer a promising route for CO2 conversion.
• Efficient CO2 conversion in plasma requires precise control over dissociation mechanisms.

Purpose of the Study:

• To investigate the mechanisms and timing of CO2 dissociation in pulsed nanosecond plasma discharges.
• To identify factors influencing efficient energy transfer and CO2 conversion.
• To understand the role of excited states and metastable conditions in plasma-driven CO2 conversion.

Main Methods:

• Utilized pulsed nanosecond discharges for CO2 conversion experiments.
• Analyzed energy deposition patterns during plasma breakdown.
• Investigated the temporal evolution of CO2 dissociation with microsecond resolution.

Main Results:

• Observed a significant time delay (microseconds) between energy deposition during breakdown and actual CO2 dissociation.
• Identified a quasi-metastable state in the plasma system during this delay period.
• Demonstrated that CO2 dissociation is primarily mediated by excited CO2 states, not direct electron impact.

Conclusions:

• Delayed dissociation mechanisms, driven by CO2 excited states, are crucial for efficient plasma-based CO2 conversion.
• The metastable condition can be prolonged by increasing energy input via additional pulses.
• Shorter interpulse times are critical for maintaining the favorable metastable state and enhancing CO2 dissociation efficiency.