METAL ORGANIC FRAMEWORK WITH TWO ACCESSIBLE BINDING SITES PER METAL CENTER FOR GAS SEPARATION AND GAS STORAGE

摘要

The separation of ethane from its corresponding ethylene is a very important, challenging and energy-intensive process in the chemical industry. Herein we report a microporous metal-organic framework Fe₂(O₂)(dobdc) (dobdc⁴⁻: 2,5-dioxido-1,4-benzenedicarboxylate) with Fe-peroxo sites for the preferential binding of ethane over ethylene and thus highly selective separation of C₂H₆/C₂H₄. Neutron powder diffraction studies and theoretical calculations demonstrate the key role of Fe-peroxo sites for the recognition of ethane. The high performance of Fe₂(O₂)(dobdc) for the ethane/ethylene separation has been validated by gas sorption isotherms, ideal adsorbed solution theory calculations, simulated and experimental breakthrough curves. Through a fixed-bed column packed with this porous material, polymer-grade of ethylene (99.99%) can be straightforwardly produced from ethane/ethylene mixtures during the first adsorption cycle, demonstrating its enormous potential for this very important industrial separation with low energy cost