Researchers in Delft (Netherlands) have developed a catalyst that is effective even in negligible quantities. The shape and robustness of the catalyst ensures that it lasts much longer in reactions, saving a lot of energy, waste and costs. The results have been published in Nature Communications.
A catalyst is present in the reaction mixture, but is not part of the chemical reaction equation. So in theory catalysts could work forever, but in practice chemists see that they become less active over time. Because of this a large quantity of the catalyst is needed to make the reaction process run smoothly. The excipients then have to be purified again from the reaction mixture, which is an intensive, costly and polluting process.
Delft researchers have discovered a new excipient that is unprecedentedly efficient. Even with homeopathic amounts of it, the reaction continues to run smoothly. In the research the chemists worked with a manganese catalyst, which hydrogenates molecules. This means that a double compound in the molecule is broken and hydrogen reaches that spot in the molecule. This reaction is mainly used in the hardening of oils and fats.
Researcher Evgeny Pidko: ‘In order to make the catalyst more effective, we started tinkering to create more binding spots per molecule. Then we noticed that the reaction suddenly went much better.’ Using spectroscopy, the researchers saw that the new catalyst shows ideal properties. When activated, it opens up to drive the required reaction. When at rest, the catalyst closes its tweezer-like arms, which protects the active part. The research of Pidko’s team shows that the catalyst can be used up to 200.000 ‘cycles’. Pidko: ‘Even at temperatures of 120 degrees Celsius it does not fall apart. Instead of the usual 1000 ppm (parts per million), only 5 ppm of the new excipient is needed. With such minute quantities, the purification step normally required can be skipped.’
According to the researchers, the development is important for making the chemical industry more sustainable, but cannot be applied directly to existing chemical processes. This requires further research.