Teflon: chemists break down harmful bonds

This great strength of the carbon-fluorine bond, which makes it useful in so many applications, also leads to multiple effects on the creation of long-lasting greenhouse gases in nature

We all love the way the breakfast omelette slides off the home non-stick pan without leaving pesky egg bits in the pan. Indeed, the carbon-fluorine bond, on which all Teflon cookware is based, is so beneficial that we also use it in clothing, lubricants, refrigerators, anesthetics, semiconductors and even blood substitutes.

However, precisely this great strength of the carbon-fluorine bond, which makes it useful in so many applications, also leads to multiple effects on the creation of long-lasting greenhouse gases in nature.

In a pioneering study published in the prestigious journal Science, researchers from Brandeis University in the USA report that they have identified a catalyst capable of effectively breaking the carbon-fluorine bond and converting it into a carbon-hydrogen bond, thus becoming environmentally friendly.

Chlorofluorocarbons (CFCs) or freons are substances harmful to the ozone layer. Hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) cause public concern because they are considered super-greenhouse gases with greater potential to harm the environment by capturing solar radiation and remaining in the atmosphere without the possibility of being destroyed.

"It is very difficult to convert the carbon-fluorine bond into other bond types under normal conditions because it is inert and inactive; This is a serious challenge for chemists," says lead author chemist Oleg Ozerov. "But we found a way to take the carbon-fluorine bond that you can't do much with, break it and convert it cleanly into something else at room temperature."

Through research support from the Ministry of Energy, the Sloan Foundation and the Ozerov Research Corporation discovered a new catalytic process for a carborane-silylium family of compounds that causes the bonds represented by the formula HFCs to react at room temperature, converting the carbon-fluorine bonds into carbon-hydrogen bonds. The silylium catalyst performs the essential task of breaking the carbon-fluorine bond by detaching a fluorine ion from the fluorocarbon compound and attaching it to a silicon atom. The final product is a compound with a silicon-fluorine bond that no longer poses a risk as a greenhouse gas.

These findings could, in the end, lead to large-scale reactions that could convert environmental pollutants containing carbon-fluorine bonds into products that could be recycled or destroyed without the need for special equipment. "The conversion of PFCs still remains a challenge and our research efforts are aimed at the design of even more active catalysts that can activate these substances," Ozerov said.

The press release from the university