Tuning Gate-Opening Of A Flexible Metal-Organic Framework For Ternary Gas Sieving Separation

In comparison with the fast development of binary mixture separations, ternary mixture separations are significantly more difficult and have rarely been realized by a single material. Herein, a new strategy of tuning the gate-opening pressure of flexible MOFs is developed to tackle such a challenge. As demonstrated by a flexible framework NTU-65, the gate-opening pressure of ethylene (C2H4), acetylene (C2H2), and carbon dioxide (CO2) can be regulated by temperature. Therefore, efficient sieving separation of this ternary mixture was realized. Under optimized temperature, NTU-65 adsorbed a large amount of C(2)H(2)and CO(2)through gate-opening and only negligible amount of C2H4. Breakthrough experiments demonstrated that this material can simultaneously capture C(2)H(2)and CO2, yielding polymer-grade (>99.99 %) C(2)H(4)from single breakthrough separation.