This work presents an experimental investigation of water adsorption in metal−organic frameworks (MOFs) at room temperature and up to 90% relative humidity. Structural degradation of the materials after regeneration is analyzed via powder X-ray diffraction (PXRD) and nitrogen adsorption measurements. MOFs with open metal sites are quite hydrophilic but appear to maintain their structure according to PXRD. However, significant surface area loss indicates that decomposition is occurring and is likely an attribute of oxygen presence during the regeneration procedure. Materials with copper paddle-wheel (HKUST-1), 5-coordinated magnesium (Mg MOF-74), and 7-coordinated zirconium (UiO-66(-NH 2 )) maintain good structural stability, while Zn-COOH containing MOFs (DMOF-1; DMOF-1-NH 2 ; UMCM-1) undergo complete loss of crystallinity.

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A mesoporous metal-organic framework (MOF) material, UMCM-1, has been synthesized and characterized using N 2 adsorption, powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared techniques. A detailed experimental study has been made of the adsorption of pure methane, hydrogen, carbon dioxide, oxygen, and nitrogen at various temperatures (298-338 K) and pressures (up to 25 bar). Multitemperature isotherms were modeled using the Dubinin-Astakhov equation to obtain useful thermodynamic properties including adsorption potential characteristic curves and isosteric heats of adsorption. Results are compared with mesoporous carbons and silicas. Large-pore materials are shown to exhibit relatively high heats of adsorption for CO 2 when open metal sites are present. This phenomenon is not observed for methane, which indicates the importance of the CO 2 quadrupole in influencing binding strength. Adsorption results for N 2 and O 2 show that selectivities in MOFs can be manipulated by the presence or absence of open metal sites. UMCM-1 and MOF-177 show a slight preference for O 2 over N 2 . However, open metal site MOFs such as Cu-BTC show the opposite adsorption preference, which is similar to zeolite selectivities. This experimental study reveals interesting adsorption information about a novel mesoporous MOF within the context of other MOFs and traditional mesoporous adsorbents. These results can be used to advance the development of structure-property relationships for metal-organic frameworks.

A comprehensive scale-up procedure for amine-functionalized UiO-66 is implemented, which leads to the development of a novel flow-through metal-organic framework synthesis process. Products are characterized via BET modeling of N 2 adsorption at 77 K and powder XRD to confirm crystal porosity and phase, respectively. Batch syntheses are conducted to examine the effects of polytetrafluoroethylene and glass vessel materials on crystal yield and quality. Intermediate samples from sealed-vessel trials at 373, 383, and 393 K are collected and characterized, which show a high degree of product consistency. Nucleation rates are determined at the same temperatures, and the Arrhenius relationship is used to predict the activation energy of nucleation, E aNuc . A continuous-flow reactive crystallization process is developed using a draft-tube type reactor. As a proof of concept, the reactor is operated for three retention times. The cumulative product, material retained within the crystallizer, and intermediate samples are collected and characterized to confirm UiO-66-NH 2 production.

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