Adsorption Mechanism of NaY Zeolite on Space Contaminants in the CO₂-rich Atmosphere of Mars

Zeolite can effectively collect space contaminants in real time, which is a new approach to control the space molecular contamination. During the long-duration flight, the Mars probe faces not only a high-vacuum environment, but also a special CO₂-rich environment in the Martian atmosphere. In order to overcome the molecular contamination of the highly sensitive analyzers and other optical sensitive parts of the Mars probe, and as well as to reduce the possibility of false-positive signs of life caused by the molecular contaminant, there is an urgent need to verify whether the zeolite molecular adsorption coating can be applied to Mars probe mission. In order to simulate the special Martian atmospheric environment, this work focuses on the adsorption behavior of NaY zeolite on toluene under CO₂ atmosphere. It is confirmed that CO₂ molecules are mainly adsorbed at the β-cage site of NaY zeolite, while toluene molecules are prefer-entially adsorbed at the “super-cage” site. So the NaY zeolite is fully applicable under the real CO₂-rich conditions in Martian atmosphere, and the adsorption properties of the coating on the low concentration molecular pollutants are not affected.