Material testing and development for plasma-assisted capture and splitting of CO2

Combining dual-functional materials (DFMs) with plasma technologies represents a promising pathway for Integrated Carbon Capture and Utilization (ICCU), allowing CO₂ adsorption and conversion in a single unit. This study investigated various adsorbents—commercial zeolites (13X, 4A, 5A), Lewatit VP OC 1065, and lab-made γ-alumina functionalized with 3-aminopropyltrimethoxysilane—used as packing media in a Dielectric Barrier Discharge (DBD) reactor for plasma-assisted CO₂ capture and conversion. An experimental campaign was conducted to assess performance and stability under three consecutive plasma cycles. Distinct desorption mechanisms were observed: functionalized γ-alumina showed a double-peaked profile, indicating fast plasma-induced desorption followed by slower thermal desorption. Lewatit displayed similar behavior in the first cycle but degraded with further exposure. Zeolites exhibited a single sharp desorption peak. Nitrogen physisorption before and after plasma exposure indicated stable physical properties for most materials, except for Lewatit, which showed a slight decrease in surface area, likely due to carbon deposition. ATR-IR spectroscopy confirmed Lewatit defunctionalization after just one plasma cycle. Functionalized γ-alumina achieved the highest CO₂-to-CO conversion (~51%) with good stability. Lewatit showed the highest CO₂ adsorption (~0.50 mmol/g) but lower conversion (~30%). Zeolite 5A also performed well in adsorption (~0.39 mmol/g) but had lower conversion efficiency (~31%). Functionalized γ-alumina stands out as a promising candidate for plasma-assisted ICCU, offering a balance between performance and durability. However, further research is needed to assess long-term stability. This study highlights the potential of amine-functionalized chemisorbents and the need for tailored DFMs to resist plasma-induced degradation.