Hybrid materials
- Coordination polymers as heterogeneous catalysts
(NFR Project#: 153869/S10 & 165847/V30)
A SINTEF/UiO cooperation | 
|
Homogeneous catalysts are known to have high activity, high selectivity and good reproducibility. However, they often suffer from fast deactivation kinetics and problematic catalyst separation in the process. The main philosophy of heterogenizing a metal complex catalysts is to maintain the good properties of the homogeneous version of the catalyst, but improve the lifetime and ease of catalyst separation. There are many ways to heterogenize a catalyst: Using a biphasic solvent system in which the catalyst and product are soluble in different phases is one approach. More common is to link the catalyst to a solid support making it possible to separate the product from the catalyst by filtration. In this case the catalyst is linked to the surface of a high surface area inorganic or organic carrier such as a metal oxide or polystyrene. The complex can be linked to the surface through heteroatoms, by ionic bonds or by simply dissolving the complex in a solvent that tend to stay on the porous carrier during the process in question. A fundamental problem in most heterogenization approaches is that the exact molecular environment of the active site in the heterogenized system is difficult to determine and sometimes impossible to reproduce. In effect, one obtains a different catalyst. This problem is most prominent when using metal oxide carriers which often have irregular surfaces with reactive hydroxyl groups.
On the other hand, for polymeric supports and for coordination polymers, a ligand system with a structure which is very close to that of the homogeneous catalyst can be built into the monomeric unit of the polymer or into the organic linker used in the coordination polymer.
The primary approach in the present project is to utilize organic molecules in the synthesis of the coordination polymer that have remaining uncoordinated functional groups in the resulting coordination polymer. If these unoccupied ligand systems are e.g. amino and phosphino groups, the catalytically active metal species can be added at a later stage. The primary aim of the present project is therefore to prepare new heterogeneous catalysts based on coordination polymers of this kind.
Publication list >>>
Core project team: