An In-Situ Transmission Fourier Transform Infrared Study on the Interaction Mechanism of Plasma with Nano-Catalyst for CO2 Methanation

The effects of discharge conditions and catalysts on CO₂ methanation under the plasma were investigated via In-Situ transmission FTIR and OES analysis. The bare Al₂O₃, Ni/Al₂O₃ and Ru/Al₂O₃ catalysts were coated on the ZnSe window using the modified sol-gel method for In-Situ transmission FTIR analysis. It was confirmed from the OES analysis that the intensity of excited hydrogen increased in all catalysts as the discharge frequency and voltage increased, and the increment of H+ peak intensity was the largest in the Ru/Al₂O₃ catalyst. In addition, it was found from the In-Situ transmission FTIR analysis that the O-H band was all disappeared as the frequency and voltage increased. In conclusion, the increased H+ with the decomposition of O-H led to the increase in the CH₄ conversion, resulting in the highest CH₄ conversion in the Ru/Al₂O₃ catalyst.