Effect of electrode materials on the CO₂ conversion performance of micro-gap cylindrical DBD plasma reactor

抄録

CO₂ decomposition is an exciting solution to the greenhouse gas problem by transforming CO₂ into a valuable energy resource. However, CO₂ splitting in traditional thermal processes requires a large amount of energy and suffers from high energy costs due to energy loss in heating the entire gas. Non-thermal plasma technology provides an alternative way to decompose CO₂ by accommodating CO₂ activation at a lower temperature while providing energetic electrons, which can activate the gas by electron impact excitation, ionization, and dissociation. In recent years, dielectric barrier discharge (DBD) reactors have become one of the most popular non-thermal plasma systems for CO₂ conversion into CO and O₂ because of their mild operating conditions, simple designs, and easy upscaling capabilities for industrial applications. However, CO₂ conversion and energy efficiency of DBD reactors are still limited and depend on plasma processing parameters and reactor design. This study investigated the effect of electrode materials on the CO₂ conversion performance of the CO₂ decomposition process in a micro-gap cylindrical DBD plasma reactor. Four materials (SUS, SS, copper, and carbon) were selected as inner electrodes of the DBD reactor. The CO₂ conversion, energy efficiency, and discharge characteristics were examined at various discharge power and gas flow rates for different electrode materials. The results show that the electrode materials determined the discharge characteristics of the DBD reactor and consequently affected the CO₂ conversion and energy efficiency of the CO₂ decomposition process.