Probing the limits of mechanical stability of the mesoporous Metal-Organic Framework DUT-76(Cu) by hydrocarbons physisorption

Herein we investigate the interaction of the highly porous metal-organic framework DUT-76(Cu) with different C1-C4 hydrocarbons at their boiling points. During adsorption the structure appeared to simply decompose however the true process is a transition into an amorphous phase with a smaller total pore volume. We used a combination of multi cycle physisorption experiments of different hydrocarbons (methane, ethane, ethylene, propane, propylene, n-butane, 1,3-butadiene) with X-ray diffraction, SEM imaging and total scattering to investigate this transition. With this methodology we were able to gain a deep understanding of occurring phenomena on the crystal structure, the local structure as well as the macroscopic behavior of the material and recognized a stronger transition with increasing chain length, number of double bonds and adsorption/desorption cycles due to adsorption stress. These multi cycle adsorption experiments can be utilized as a semi-quantitative tool to test the mechanical stability of highly sensitive mesoporous materials.