Zeolites master challenging mixtures
© Dorling Kindersley/Getty
Adding atomically dispersed metal ions to porous materials known as molecular sieves dramatically boosts their capacity to separate problematic mixtures of industrial chemicals.
Organic chemicals called lower olefins are the starting materials for many common polymers. However, they invariably contain alkyne impurities, which poison the polymerization catalyst. Current methods for removing the alkynes are inefficient, energy intensive and expensive.
Zeolites, also known as molecular sieves, are inexpensive porous materials used in many industrial purifications. However, they have been unable to separate olefins and alkynes because the two components in the mixture are very similar in size.
Now, a team led by Nankai University researchers has shown that zeolites can be modified to readily separate olefins and alkynes with high selectivity. They achieved this by incorporating nickel ions, which strongly bind to alkynes, into the pores within the zeolite structure.
- Science 368, 1002–1006 (2020). doi: 10.1126/science.aay8447