SAPO family as greenhouse gas plasma assisted capture system for atmospheric remediation

The direct capture of CO2 and CH4 from the atmosphere to stabilize their concentration in the air to control global warming is accelerating. There are continued efforts to develop and optimize different technologies for direct capture of these greenhouse gases from air. In this work we employed a SAPO zeolite family as efficient and robust CO2 and CH4 adsorbents at standard temperature and pressure conditions. Herein, we demonstrated the possibility of employing nonthermal plasma to desorb and react these greenhouse gases. The desorption of the gases under study were performed when employing gentle plasma pulses of Kr. Interestingly, the desorption of CO2 and CH4 occurred when the plasma was turned off, which is opposite to the case of other small pore size materials studied by our group, such as MOF-177. Suggesting a kinetically limiting process rather than a thermodynamically dominated phenomenon. The zeolite SAPO-56 resulted in a maximum CH4 desorbed molar flow rate of 23.27 µmol min-1 when applying a plasma disturbance. While for CO2 the maximum desorbed molar flow rate was 28.43 µmol min-1 . When reacting CH4 and CO2 under plasma environment for the specific case of SAPO-56 at (5:1) (CH4: O2) flow ratio, we observed the highest CH4 and CO2 conversions of 10.39% and 11.12% respectively. We concluded that this type of acidic catalyst resulted in a higher production of CO compared to the methanol formation. We expect this preliminary understanding of the adsorptionreaction system under non-thermal plasma environment can lead to future atmospheric remediation technologies.