Auto-methanation using plasma catalysis at room temperature

Recently, it has been reported that combined oxygen supply promotes the auto-methanation of CO₂ at room temperature, which opens a new pathway for the conversion of CO₂. In our previous studies, it was confirmed that plasma catalyst systems contribute to enhanced methanation, but there is no precedent whether auto-methanation can be achieved using plasma catalysis. In this study, we developed automatic methanation using plasma catalysis at room temperature and compared the CO₂ conversion at different air pressures at the same GHSV. The results show that CO₂ conversion can be 100% when the H₂/CO₂ ratio is greater than 5 times, and when the H₂/CO₂ ratio is 5 times, the CO₂ conversion at low pressure reaches more than 90% compared to high pressure. Automated methanation is achieved at both pressures, with 91% CO₂ conversion at 30 kPa at a lower temperature (310°C), while it takes 380°C at 80 kPa to achieve the same conversion. This study confirms that auto-methanation can be achieved at room temperature using a packed-bed DBD reactor with a plasma catalytic system, opening up a new way of using plasma to convert CO₂ and providing the feasibility for further mechanistic analysis