The end products of the reaction, hydrocarbons and fluorosilanes, do not have greenhouse-gas properties and are easier to dispose of than fluorocarbons.
Ozerov and Douvris tried out their catalytic method on three fluorocarbon test substrates. In each case, they were able to get almost all of the material to react; one substrate took just six hours to break down completely, at only 25 °C.
Robin Perutz, a catalyst expert at the University of York, in the U.K., says that Ozerov and Douvris’s method is “an impressive discovery. It’s really important to convert problematic fluorocarbons into something fairly harmless, and at the moment this can only be done by extremely high-temperature chemistry. These guys have said we can do an awful lot just at room temperature, and that’s a big step towards getting rid of more unwanted fluorocarbons.”
There are a few challenges to meet before the catalyst could be used to clean up fluorocarbons on a large scale, however. To begin with, cheaper sources would need to be found for the silicon-based reagents, says Ozerov.
Véronique Garny, director of the Fluorinated Chemicals Groups at the European Chemical Industry Council, says that even then it might be hard for the catalyst technique to beat the established methods. Fluorosilanes, Ozerov acknowledges, have some toxicity–although he says that they “can easily be processed further.” But according to Garny, the existing techniques “are simpler, have completely nontoxic end products, and work fine with highly contaminated starting materials, something which Ozerov’s process still needs to show.”
Garny sees more potential for the catalyst method in attacking solid and liquid fluorocarbons that pollute land and water. Perutz points out, however, that these pollutants are often particularly hard to break down because they are extra rich in strong fluorine-carbon bonds. Ozerov and Douvris have not yet tested their method against such recalcitrant fluorocarbons.
“The technique still has quite a long way to go before it can be used widely,” says Perutz. “But it’s certainly a very promising step with a lot of potential.”