In Situ Neutron Diffraction of Zn-MOF-74 Reveals Nanoconfinement-Induced Effects on Adsorbed Propene

Even though confinement was identified as a common elementof selectivecatalysis and simulations predicted enhanced properties of adsorbateswithin microporous materials, experimental results on the characterizationof the adsorbed phase are still rare. In this study, we provide experimentalevidence of the increase of propene density in the channels of Zn-MOF-74by 16(2)% compared to the liquid phase. The ordered propene moleculesadsorbed within the pores of the MOF have been localized by in situneutron powder diffraction, and the results are supported by adsorptionstudies. The formation of a second adsorbate layer, paired with nanoconfinement-inducedshort intermolecular distances, causes the efficient packing of thepropene molecules and results in an increase of olefin density.

Automated summary

Despite being identified as a common element and simulations predicting enhanced properties, experimental characterization of adsorbed phase in selective catalysis is scarce. This study presents experimental evidence of a 16(2)% increase in propene density within the channels of Zn-MOF-74 compared to the liquid phase. In situ neutron powder diffraction localizes ordered propene molecules adsorbed in MOF pores, supported by adsorption studies, causing efficient packing and increased olefin density.