In-Situ Chemical Trapping of Oxygen in the Splitting of Carbon Dioxide by Plasma

A crucial step in the plasma splitting of carbon dioxide is the separation of the conversion products, and this is not straightforward, especially for separating O-2 from CO2 and CO. In this work the trapping of atomic oxygen by adding a hydrogen source, which enhances the chemical conversion into water, is demonstrated. The experimental and modelling results show that by adding 3% of H-2 and 2% of CH4 most of the oxygen can be trapped at a CO2 conversion of +/- 2.5%. The identified products formed by the addition of CH4 or H-2 are mainly H2O and in the case of CH4 also H-2. Adding a hydrogen source thus leads to the removal of O-2, leaving behind a gas mixture that can be more easily separated.