Utilizing the Gate-Opening Mechanism in ZIF-7 for Adsorption Discrimination between N2O and CO2

N2O is a greenhouse gas with tremendous global warming potential, and more importantly it also causes ozone depletion; thus, the separation of N2O from industrial processes has gained significant attention. We have demonstrated that N2O can be selectively separated from CO2 using the zeolite imidazolate framework ZIF-7. The adsorption/desorption isotherms of both N2O and CO2 in ZIF-7 indicate the gate-opening mechanism of this material, and surprisingly, the threshold pressure for the gate opening with N2O is lower than that with CO2. Theoretical calculations indicate that both gas–host and gas–gas interaction energies for N2O are more favorable than those for CO2, giving rise to the difference in the threshold pressure between N2O and CO2 in ZIF-7. Breakthrough experiments for N2O/CO2 mixtures confirm that ZIF-7 is capable of separating N2O and CO2 mixtures under the optimized conditions, in reasonable agreement with simulation results, making it a promising material for industrial applications.