High CO2 separation performance on a metal-organic framework comprised of Nano-cages lined with ultra-high density of dual-side open metal sites

Developing efficient adsorbents for CO2 separation is the key step of CO2 sequestration which has found many applications including carbon capture from flue gas and natural gas purification. Although many adsorbents have been reported in the past decades, the development of efficient adsorbent with both high separation selectivity and excellent capacity is technically challenging due to the trade-off effect between adsorption capacity and selectivity. In this work, we report the CO2 separation performance of a microporous MOF which comprise of nano-cages and ultra-high density of dual-side open metal sites. Adsorption results reveal a prominent CO2 uptake and outstanding separation selectivity for CO2/N2 and CO2/CH4. Furthermore, this MOF also exhibit preferable adsorption of C2~C3 light hydrocarbons over CH4. Simulation studies reveal that the dual-side open metal sites are the preferable adsorption sites for CO2, C2H4 and C3H6. Therefore, the outstanding separation performance can be attributed to the combined effects of nano-cages and high density of open metal sites.