Research on In-situ Oxygen Production Technology from Martian CO₂ Based on Microwave Plasma Discharge

Mars is the core target for humans to achieve long-term extraterrestrial residence, and in-situ oxygen production technology, as the lifeline of material-life support for Martian bases, is a key variable determining the success or failure of Mars exploration missions.

Existing mainstream solutions, such as the electrochemical method (MOXIE device), high-temperature electrolysis method (solid oxide electrolyzer), and biological method, are all confronted with the dilemmas of efficiency limitations and poor environmental adaptability. Taking the currently most mature MOXIE device as an example, its oxygen production process requires additional consumption of a large amount of energy to maintain a pressurized and heated environment, with the heating and pressurizing power exceeding 200 W. Therefore, the characteristics of current Martian in-situ oxygen production equipment, such as high energy consumption and low energy utilization efficiency, still pose a huge challenge for future large-scale deep space exploration applications.

At present, mainstream oxygen production technologies share common bottlenecks in extraterrestrial scenarios, including low efficiency, high energy consumption, large volume, and stringent requirements for environmental conditions. These technical bottlenecks have severely restricted the scale and sustainability of deep space exploration.

To address the demand for efficient in-situ oxygen production from Martian CO₂, this study proposes a novel conversion technical route of "ECR low-temperature plasma + synergistic catalysis". We utilized a microwave source to generate 2.45 GHz microwaves, which were transmitted to a vacuum reaction chamber through a BJ-26 waveguide and a ceramic window, forming ECR plasma under the confinement of an 875 G magnetic field. Multi-component gas injection was adopted to synergize with CO₂ for atomic oxygen dissociation, and a high-efficiency microwave excitation system was applied to realize and maintain ultra-low-power CO₂ dissociation. A spectrometer was used to monitor characteristic spectral lines in real time, including atomic oxygen (777.2 nm) and carbon monoxide molecules (483.5 nm), and clear characteristic spectral lines of atomic oxygen were detected. In particular, we estimated the total energy consumed for oxygen generation via CO₂ dissociation and found that it accounted for more than half of the total microwave energy injected into the vacuum chamber, which verified the efficient conversion of carbon dioxide into oxygen. In addition, to improve the dissociation efficiency, Martian trace gases (Ar and N₂) were added. The results showed that trace amounts of Ar and N₂ were conducive to the dissociation and conversion of carbon dioxide.