Producing Oxygen and Fertilizer with the Martian Atmosphere by Using Microwave Plasma

We explore the potential of microwave (MW)-plasma-based in situ utilization of the Martian atmosphere with a focus on the novel pos-sibility of fixing N2 for fertilizer production. Conversion in a simulant plasma (i.e., -96% CO2, -2% N2, and -2% Ar), performed under en-ergy conditions similar to those of the Mars Oxygen In Situ Resource Utilization Experiment (MOXIE), currently on board NASA's Perse-verance rover, demonstrates that O/O2 formed through CO2 disso-ciation facilitates the fixation of the N2 fraction via oxidation to NOx. Promising production rates for O2, CO, and NOx of 47.0, 76.1, and 1.25 g/h, respectively, are recorded with corresponding energy costs of 0.021, 0.013, and 0.79 kWh/g, respectively. Notably, O2 production rates are -30 times higher than those demonstrated by MOXIE, while the NOx production rate represents an -7% fixa-tion of the N2 fraction present in the Martian atmosphere. MW -plasma-based conversion therefore shows great potential as an in situ resource utilization (ISRU) technology on Mars in that it simulta-neously fixes N2 and produces O2.