Catalysts are involved in more than 95% of the production of chemicals, fuels, pharmaceuticals and consumer goods. They often consist of toxic elements that are difficult to remove from the final end product and usually get destroyed during that process. A solution to this is to “capture” such catalysts in cage like materials that hold the catalyst without decreasing it’s activity. Afterwards, the “catalyst in the cage”, comparable to a “ship in a bottle” can be easily be separated and reused time and time again. A good catalyst is 100% efficient, creating no side products or waste.
A nice example of these concepts is shown in this original research paper by the COMOC (Van Der Voort) group at the UGent. In the cover picture, the purple POMs (active catalytic species) are captured in the green scaffold, known as a Metal Organic Framework. The blue molecule is an ionic liquid that facilitates this and attracts the alcohol (left) to the catalyst where it is converted with 100% selectivity to an aldehyde (right).