Experimental Study on CO 2 Methanation by Dielectric Barrier Discharge Plasma over γ-Al 2 O 3 supported Co catalyst

Global climate change driven by greenhouse gas emissions, especially CO2, has become a serious challenge, and the issue of CO2emission reduction has attracted much attention. In this study, based on the dielectric barrier discharge (DBD) plasma experimental platform, the effect of self-made γ-Al2O3supported Co (γ-Al2O3@Co) catalyst on CO2methanation was investigated, and the variation of CO2conversion and product selectivity under different input power conditions was analyzed. The experimental results show that with the increase of input power, the CO2conversion and CH4selectivity of the three reaction systems—without filling, with γ-Al2O3filling and with γ-Al2O3@Co catalyst filling—progressively increase. At normal temperature and pressure, when the input power is 100W, the CO2conversion in the reaction system filled with γ-Al2O3@Co catalyst reaches 72.3%, with a CH4 selectivity as high as 98.5%. Catalyst characterization indicates that the Co species in the γ-Al2O3@Co catalyst mainly exist in the forms of Co0, CoO, and CoAl2O4, and exhibit good structural stability and catalytic activity before and after the reaction. The excited species generated in the DBD plasma, including CO*, CH*, and H*, synergistically interact with Co0active sites on the catalyst surface, thereby promoting efficient CO2conversion. This study provides a novel catalytic system and experimental evidence for CO2methanation.