The steady removal of carbon dioxide (CO2) from diverse gas
streams is a critical step toward achieving the blueprint of carbon
neutrality and clean energy production. However, the associated
energy and capital inputs are considerably high, necessitating the
development of effective technologies for CO2 separation. Here,
we report a special CO2-recognition membrane based on a fluorinated metal-organic framework (KAUST-7) for efficient CO2 capture
from various mixtures including CO2/H2, CO2/CH4, and CO2/N2.
Uniquely, the appropriate CO2 affinity cooperating with the confined aperture of KAUST-7 enables the membrane with the right
orientation to be nearly only permeable to CO2, showing unprecedented CO2 separation selectivity over both smaller (H2) and larger
(N2, CH4) molecules. The extraordinary performance is maintained
after treatment with corrosive hydrogen sulfide or humid atmospheres, swing temperatures or pressures, and long-term operations, pinpointing the potential for high-throughput CO2 capture
in a continuous mode.