CO2/CH4 Glow Discharge Plasma. Part II: Study of Plasma Catalysis Interaction Mechanisms on CeO2.

In situ FTIR transmission experiments for CO 2 and CO 2 – CH 4 plasma were performed for a fundamental study of surface plasma interaction with cerium oxide ( CeO 2 ) as catalytic surface. Utilizing a DC glow discharge plasma reactor at low pressure, it was observed that CO 2 gas adsorbs in the surface forming tridentate carbonates and hydrogen carbonates. When CO 2 – CH 4 plasma is ignited, formate species were formed while carbonate species disappeared from the surface. The CeO 2 pellet has also been placed downstream the plasma in order to observe the role of the gas composition at the exit of CO 2 – CH 4 plasma on CeO 2 without any heating or strong electric field. In addition, the effect of water was investigated in several surface phenomena. OH groups play an important role in the reaction with tridentate carbonates to generate formates under plasma. The gas phase chemistry of the CO 2 – CH 4 plasma used here has been described in details in the part I of this work. The conclusions drawn on the gas phase contribute to the understanding of the observed phenomena on CeO 2 . These results enlighten the complex mechanisms occurring during CO 2 – CH 4 plasma reactions on surfaces that could help in the improvement of CO 2 recycling. [ABSTRACT FROM AUTHOR]