CO₂Reduction by Multiple Low-Energy Electric Discharges in a Microstructured Reactor: Experiments and Modeling

The simple, robust, and energy-efficient reduction of CO₂to useful products is a significant goal of modern chemistry and chemical engineering. In this study, a novel CO₂reduction process was introduced by employing multiple low energy non-thermal electric glow discharges at the microscale. The process is neither dependent on limited lifetime catalysts nor consumable chemicals, enabling continuous operation over long periods, and operates at atmospheric pressure and temperature, thus simplifying process implementation. The influence of three parameters on the conversion of CO₂within the active volume and energy efficiency was studied, namely, the relative operational regimes on the V-I curve, the residence time of the reactant gas mixture in the plasma region, and the CO₂to water vapor molar ratio. High energy efficiencies of 80-95% and a CO₂conversion of 70-80% can be achieved in the active volume. A mathematical model reflecting geometry and flow conditions inside the microreactor was developed to simulate the chemical reaction process. Through an optimization process, the mathematical model parameters were determined to fit the experimental data and predict primary reaction constants for CO₂reduction.