Added to this the simple one-pot synthesis is also proving more favourable over the usual multi-step preparation procedures more commonly found.
Metal organic frameworks (MOFs) have attracted the attention of scientists all around the world during the last decade, resulting in an unprecedented explosion of publications on the topic. The combination of organic and inorganic subunits on fully crystalline porous materials has led to a vast chemical versatility, giving rise to more than 10,000 MOF structures.
Considering the vast number of structures discovered, only a few applications have been investigated fully, attention has focused on discovering new structures together with the characterization and identification of new and novel properties such as luminescence, magnetic properties, gas storage, and adsorptive separation.
The group at Delft successfully developed a procedure for the direct encapsulation of polyoxometalates (POMs) into MIL-101(Cr). The addition of phosphotungstic acid (PTA) to the synthesis mixture of MIL-101 leads to the direct encapsulation of chromium-containing polyoxometalates (POMs) inside the MOF structure with a good distribution over the MIL-101 crystals.
These new catalysts show the highest activities reported to date at 313 K for the Knoevenagel condensation of benzaldehyde with ethyl cyanoacetate when using apolar toluene as solvent as well as when using polar DMF and ethanol, with TOFs exceeding 600 h−1. In addition, they exhibit a remarkable activity in two acid-catalyzed reactions, the esterification of n-butanol with acetic acid in liquid phase slurry operation and the dimethyl ether production from methanol in a fixed bed gas phase operation.