Probing the Interaction of Plasma with Nano-Catalysts for CO₂ Conversion Using In-Situ Diffuse Reflectance Infrared...

The effect of γ-Al₂O₃ and Ce/Al₂O₃ nano-catalysts under plasma on CO₂ conversion was investigated via In-Situ DRIFTS. The adsorption of CO₂ on the nanoparticle of γ-Al₂O₃ surface caused to produce the carbonate species, of which the amount was dependent on temperature. In addition, we confirmed that the formation of carbonate could be more activated by plasma. The Ce nano-catalyst played a role to inhibit the production of carbonate on the surface of Al₂O₃ under the plasma. Indeed, when the Ce/Al₂O₃ catalyst was exposed to plasma-excited CO₂, the carbonate was almost eliminated at over 300 °C, resulting in the improved CO₂ conversion. Notably, the Ce-promoted catalyst was able to enhance the formation of intermediate formate species by the plasma-excited CO₂. Consequently, the formed intermediate species facilitated the generation of CO by the reaction of formate and bicarbonate.