Investigation by Raman Spectroscopy of the Decomposition Process of HKUST-1 upon Exposure to Air

Abstract

We report an experimental investigation by Raman spectroscopy of the decomposition process of Metal-Organic Framework (MOF) HKUST-1 upon exposure to air moisture (T=300 K, 70% relative humidity). The data collected here are compared with the indications obtained from a model of the process of decomposition of this material proposed in literature. In agreement with that model, the reported Raman measurements indicate that for exposure times longer than 20 days relevant irreversible processes take place, which are related to the occurrence of the hydrolysis of Cu-O bonds. These processes induce small but detectable variations of the peak positions and intensities of the main Raman bands of the material, which can be related to Cu-Cu, Cu-O, and O-C-O stretching modes. The critical analyses of these changes have permitted us to obtain a more detailed description of the process of decomposition taking place in HKUST-1 upon interaction with moisture. Furthermore, the reported Raman data give further strong support to the recently proposed model of decomposition of HKUST-1, contributing significantly to the development of a complete picture of the properties of this considerable deleterious effect.

Metal‐Organic Frameworks as Catalyst Supports: Influence of Lattice Disorder on Metal Nanoparticle Formation

“…Therefore, we can conclude that Basolite® F300 is structurally perturbed compared to the highly ordered MIL‐100(Fe). Additional Raman spectroscopy reveals that the band intensity ratio of 1606 cm −1 ν (C=C) to 1550 cm −1 ν (O−C−O) asymmetric is higher for Basolite® F300 compared to MIL‐100(Fe) (Figure S1 in Supporting Information) . This suggests that O‐C‐O bond vibrations are less intense for disordered Basolite® F300, as a consequence of increased O‐C‐O bond disorder due to structural perturbation.…”

“…Additional Ramans pectroscopy reveals that the band intensity ratio of 1606 cm À1 n(C=C) to 1550 cm À1 n(OÀCÀO) asymmetric is higher for Basolite F300 compared to MIL-100(Fe) ( Figure S1 in Supporting Information). [14] This suggestst hat O-C-O bond vibrations are less intense for disordered Basolite F300, as a consequence of increased O-C-O bond disorderd ue to structural perturbation.This further suggests that structuraldisorder affects bond vibrations.…”

Direct observation of dimethyl sulfide trapped by MOF proving efficient removal of sulfur impurities

“…4a). 25 Aer the removal of water by heating, the peak of the Cu-OH 2 vibration disappeared, and the peak of the Cu-Cu vibration was shied to the higher energy region at 230 cm À1 (Fig. 4b).…”

Micro-spectroscopy of HKUST-1 metal–organic framework crystals loaded with tetracyanoquinodimethane: effects of water on host–guest chemistry and electrical conductivity

“…It is known that HKUST-1 crystals have a limited stability with respect to moisture and water, having potential consequences ranging from Cu reduction to pore collapse depending on the exposure time and water vapour pressure. [43][44][45][46][47][48] To ensure that no such effects occur during the hydration experiments in this work, in situ XRD experiments were performed by recording diffractograms during a temperature-programmed experiment with dosing of water-saturated He gas (60 mL min À1 He flow through a bubbler filled with demineralized H 2 O following the temperature program depicted in Fig. S4 (ESI †), at a heating rate of 5 K min À1 ).…”