In situ FTIR study of 2D-carbon materials for CO2 splitting under non-thermal plasma environment – selective CO production

Abstract

Carbon dioxide conversion has been considered a promising solution to global warming and the storage of renewable energy as a source of CO. However, it is challenging to develop a process that combines complete conversion from one oxidant (CO₂) to another – O₂. In this study, CO₂ splitting has been investigated and monitored in situ, by using the plasma generated in a glow discharge reactor packed with carbonaceous materials. The results presented in the form of 2D-carbon surface FTIR spectra indicate that materials play here at least a double role as: (i) a solid adsorbent and (ii) an oxygen scavenger, shifting the overall reaction equilibrium to CO – the product side. It was proved that excited surface CO₂ species are present as active intermediates. Their origin is not only the transformation from physically adsorbed molecules but also from CO and C–O surface oxides formed through the Boudouard reaction. Microscopic and Raman spectroscopy investigations confirm this statement.