Chemists at Goethe University Frankfurt have developed a new catalyst capable of selectively breaking down per- and polyfluoroalkyl substances (PFAS), known as "forever chemicals."
Chemists at Frankfurt Goethe University have developed a novel catalyst capable of selectively breaking down per- and polyfluoroalkyl substances (PFAS), compounds known as "forever chemicals."
While PFAS are widely used to create dirt- and water-resistant surfaces, they have become an increasingly significant concern due to their persistence in nature and potential health risks. The key distinction of this new catalyst is its use of different and more suitable materials instead of expensive or toxic heavy metals such as platinum, palladium or iridium. Beyond its ability to break down PFAS, the catalyst can also be used in pharmaceutical synthesis.
PFAS are remarkable molecules in many respects. Even a very thin layer can repel water, oil and dirt. Due to their high resistance to heat and UV light, they are widely used in breathable outdoor clothing, stain-resistant carpets, disposable tableware, irons and non-stick cookware. In industry, PFAS are used in lubricants, surfactants, wetting agents, chrome plating and fire-suppression foams. In short, PFAS are nearly everywhere.
However, these advantages come with certain drawbacks. Because PFAS are highly resistant, they persist in the environment long after their intended use. While they can be almost completely destroyed in waste incineration facilities, they can accumulate in material cycles during recycling processes (such as textiles or sewage sludge) and enter the environment. PFAS can be found in water, soil, plants and even the human body. This is particularly concerning because some of the approximately 4,700 known PFAS compounds are thought to be potentially carcinogenic or cause other health problems.
The key to PFAS effectiveness and environmental persistence lies in the extremely stable molecular structure, particularly of carbon-fluorine (C–F) bonds. A team of chemists led by Professor Matthias Wagner at the Frankfurt Goethe University Institute of Inorganic and Analytical Chemistry has developed a catalyst that can break these C–F bonds in seconds at room temperature. At the heart of the catalyst are two boron atoms embedded in a carbon structure in a manner resistant to air and moisture—a rare and highly practical property for boron compounds.
Christoph Buch, lead author of the study and doctoral researcher in the Wagner group, explained: "To break C–F bonds, we need electrons, and our catalyst transfers these electrons with extraordinary efficiency. So far, we have used alkali metals like lithium as electron sources, but we are already working on transitioning to electric current. This will make the process both much simpler and more efficient."
Wagner notes that the catalyst has broader applications beyond PFAS breakdown: "Many pharmaceutically important substances contain fluorine atoms to increase physiological stability and enhance their effect. Fluorine atoms also improve the drug's uptake into the body. With this catalyst, we will have the ability to precisely control the degree of fluorination in these compounds."
Gallery
