C₂H₂/CO₂ Separation with a Chain-Type Zn Pyrazolate MOF

A novel Zn dipyrazolate metal-organic framework (MOF), Zn(azbpz) (azbpz(2-)=4,4 '-azobis(3,5-dimethylpyrazolate), has been synthesized and structurally characterized using micro-crystal electron diffraction. The framework contains chain-type secondary building units comprised of tetrahedral Zn2+ ions bridged by pyrazolate groups, resulting in guest-accessible channels lined with methyl and azo functional groups. CO2, C2H2, C2H4, C2H6, C3H6, and C3H8 gas adsorption isotherms were measured to investigate the potential of Zn(azbpz) as an adsorbent for selective separation of binary gas mixtures. The data reveal selective adsorption of acetylene over CO2, and column breakthrough experiments demonstrate good performance for C2H2/CO2 separation.