Direct Visualization of Supramolecular Binding and Separation of Light Hydrocarbons in MFM-300(In)

The purification
of light olefins is one of the most important
chemical separations globally and consumes large amounts of energy.
Porous materials have the capability to improve the efficiency of
this process by acting as solid, regenerable adsorbents. However,
to develop translational systems, the underlying mechanisms of adsorption
in porous materials must be fully understood. Herein, we report the
adsorption and dynamic separation of C2 and C3 hydrocarbons in the metal–organic framework MFM-300­(In),
which exhibits excellent performance in the separation of mixtures
of ethane/ethylene and propyne/propylene. Unusually selective adsorption
of ethane over ethylene at low pressure is observed, resulting in
selective retention of ethane from a mixture of ethylene/ethane, thus
demonstrating its potential for a one-step purification of ethylene
(purity > 99.9%). In situ neutron powder diffraction
and inelastic neutron scattering reveal the preferred adsorption domains
and host–guest binding dynamics of adsorption of C2 and C3 hydrocarbons in MFM-300­(In).