The zero loading heat of adsorption for CO2 reported by Lin et al. was -39 kJ mol -1 ; in the original article, the authors also reported CO2/N2 selectivity of 230 for 10:90 CO2/N2 mixture, based on the Ideal Solution Theory. CALF-20 proved to be a stable material, amiable to the industrial scale up. Remarkably, it retained high performance in humid conditions (below 40% relative humidity) by effectively rejecting water. The exact mechanism of the suppressed water adsorption was investigated in the original article and several follow up studies (e.g. Ref ).