Contribution of active species generated in plasma to CO₂ methanation

Abstract

CO2 methanation is an effective technology for CO2 reduction. Generally, methanation reactions are accelerated using thermal catalysts. However, the temperature control is difficult because CO2 methanation is an exothermic reaction, and the catalyst is deactivated by overheating. Plasma catalysis can solve this problem by driving this reaction at lower temperatures. Therefore, in this study, we investigated the contribution of the active species generated in the plasma to CO2 methanation. We found that the density of active species is linearly related to the power density, and in particular, the CH4 generation rate is determined by the CO-derived active species, not the H-derived active species. Furthermore, with an increase in the catalyst temperature, a new reaction pathway for CH4 production is added. The results of this study contribute to the understanding of the relationship between the active species produced in plasma and CO2 methanation.