Time dependent water uptake in Cu3(btc)2 MOF: Identification of different water adsorption states by 1H MAS NMR

Mapping the Cu-BTC metal–organic framework (HKUST-1) stability envelope in the presence of water vapour for CO2 adsorption from flue gases

“…So far, only a few theoretical [28] and experimental investigations [32][33][34] on the stability of HKUST-1 have been reported. BET surface area of HKUST-1 was found to decrease by 52% (from 1340 to 647 m 2 g À1 ) after an extreme water stability test, i.e.…”

“…24 h immersion in deionised water at 50°C [32]. An investigation based on 1 H and 13 C NMR spectroscopy also revealed that water adsorption (at room temperature) has a strong influence on the carboxylate carbon resonance, jeopardising the Cu-BTC coordination [33]. Rezk et al evaluated several MOFs for adsorption cooling and demonstrated the thermal instability of HKUST-1 based on the clear hysteresis between the measured adsorption and desorption isotherms at 52°C [34].…”

Density functional theory meta-GGA + U study of water incorporation in the metal-organic framework material Cu-BTC

“…They found, at room temperature, dynamic hydrogen bonds, one O W (quasi)-statically bound to each exposed hydroxyl unit, and additional water molecules that move fluidly. This is akin to the picture discussed in an NMR study on Cu-BTC, [20] where they conclude that there are two types of water molecules: one type bound to Cu, and the other fluid. The experimental X-ray powder diffraction refinement of Cu-BTC, showing 2.3 O W binding sites per Cu, [21] suggests that more water molecules are (quasi)-static than just those immediately bound to the Cu, but that any additional water molecules in the remaining pore space may be fluid as their oxygen positions are not resolved.…”

A fiber optic sensor with a metal organic framework as a sensing material for trace levels of water in industrial gases

“…Adsorbed water molecules are located close to copper ions in the Cu-BTC. The details of water adsorption on Cu-BTC have been simulated computationally and studied with NMR [40,41,42].…”