A palladium-coated membrane removed more than 90% of each of six per- and polyfluoroalkyl substances, or PFAS, from contaminated water during a 58-day experiment while stripping away about 83% of the fluorine in the mixture. The peer-reviewed study, published in the Proceedings of the National Academy of Sciences on October 19, 2026, demonstrates a system that both captures PFAS and chemically breaks down their carbon-fluorine bonds through hydrodefluorination. The result was measured with a mixture of six PFAS of regulatory concern; the experiment did not establish how the membrane would perform with every PFAS compound or at full water-treatment scale.
PFAS are widely used because they are extremely durable and versatile. The supplied research traces their use to products including Teflon, a coating that resists oil, heat, stains, grease and water, and notes that PFAS are now found in paints, adhesives, furniture, carpets, cosmetics, semiconductors and waterproof fabrics. They are also used in firefighting foams.
The same persistence that makes these products useful allows PFAS to remain in water, soil, food and living organisms. The research reports that contamination is widespread in groundwater, wastewater and soil, with particularly high concentrations often found around wastewater-treatment facilities, landfills, airports and military bases where PFAS-containing firefighting foams have been used. PFAS can also enter crops and accumulate in fish, livestock and wildlife, creating additional routes of human exposure.
The source notes that exposure to some PFAS has been associated with cancers, thyroid disease, immune-system effects, reduced fertility, pregnancy complications, developmental problems, obesity and elevated cholesterol. PFOS and PFOA have been listed under the Stockholm Convention on Persistent Organic Pollutants. Risks across the broader PFAS family remain difficult to assess because thousands of compounds exist and only a small fraction have been thoroughly tested for toxicity.
These observations describe the scope of the contamination problem addressed by the study rather than outcomes measured in the membrane experiment itself. The difficulty of destroying PFAS begins with their molecular structure. In many of the compounds, a chain of carbon atoms is almost completely surrounded by fluorine atoms, creating an exceptionally stable arrangement.
Bruce Rittmann, director of Arizona State University’s Biodesign Swette Center for Environmental Biotechnology and leader of the study, described the carbon-fluorine bond as the strongest bond in organic chemistry. Because fluorine effectively shields the carbon backbone, conventional biological and chemical processes have difficulty finding a place to begin breaking the molecule apart. The researchers therefore used hydrogen as the means of attacking those bonds, but first had to activate it with a catalyst capable of generating a highly reactive form.
To accomplish that task, the team coated tiny membrane fibers with palladium nanoparticles and supplied hydrogen gas through the membrane. The palladium splits hydrogen-gas molecules into individual hydrogen atoms, producing reactive hydrogen capable of attacking PFAS. PFAS molecules approaching from the surrounding water attach to the palladium surface as well.
With the pollutant and reactive hydrogen together, palladium enables the reaction that breaks the carbon-fluorine bonds. As Rittmann explained, the palladium attracts both the PFAS molecule and the hydrogen and brings them together. The approach differs from activated-carbon adsorption, ion exchange and membrane filtration, which can capture PFAS but leave the contaminants in spent filters, brines or concentrated waste that must still be handled or disposed of.
Delivery of hydrogen is a central feature of the membrane. Rather than simply mixing hydrogen into the contaminated water, the researchers fed it from inside the membrane and directly into the base of the palladium layer. This inside-out delivery allows the membrane to do more than retain PFAS at its outer surface: it also supplies the reactive hydrogen needed to dismantle molecules after they reach the catalytic layer.
The design adapts a related membrane technology previously developed by Rittmann’s group to deliver hydrogen to pollutant-degrading bacteria. In the PFAS study, however, the microbes were replaced by palladium, which uses hydrogen to attack the persistent fluorinated compounds. The researchers tested the method across six PFAS of regulatory concern, and Rittmann said the mechanism worked for all six.
For nearly two months, the system continuously treated water containing a mixture of the six compounds. It removed more than 90% of each compound and achieved about 83% fluorine removal overall. Those measurements indicate that the pollutants were being chemically dismantled rather than only filtered from the water.
The reported result is specific to the six-compound mixture and experimental setup; the source does not describe removal percentages for other PFAS, other mixtures or full-scale treatment facilities. The 58-day run also showed that the system could operate continuously. The source identifies a possible treatment sequence in which conventional PFAS-removal methods first concentrate contaminants from large volumes of water into a smaller waste stream.
The catalytic membrane could then treat that concentrated stream, allowing captured PFAS to be chemically broken down rather than simply stored or disposed of intact. That integrated treatment sequence was presented as a potential application; the reported experiment itself involved the catalytic membrane treating water containing the six-PFAS mixture. Engineering and cost remain important considerations before the technology can be applied more broadly.
Rittmann said reducing the amount of palladium used is one of the group’s leading research priorities, noting that palladium costs about $50,000 per kilogram. Because hydrodefluorination removes fluorine from the original compounds, the identities and properties of the resulting products are relevant to evaluating the process. The source does not report a complete toxicological analysis of those products, so the experiment does not establish that the treated water is suitable for drinking or that the process is ready for deployment as a finished treatment system.
The same membrane platform may have broader applications. Rittmann’s group is developing hybrid versions that combine palladium nanoparticles with pollutant-degrading bacteria, allowing the catalyst and microorganisms to attack contaminants through different mechanisms. Rittmann said the group had demonstrated that this combined approach works, although the supplied report gives no quantitative performance results for it.
The PFAS experiment shows how hydrogen-delivery membranes can be adapted for a chemical catalyst rather than relying on microbes alone. It also offers a distinct approach to a persistent contamination problem: rather than only separating PFAS from water and transferring them to another waste stream, the membrane seeks to dismantle the carbon-fluorine framework responsible for their durability. The demonstrated result is a 58-day treatment of six PFAS with more than 90% removal of each compound and approximately 83% overall fluorine removal, with further engineering still required for practical use.
Subject of Research: Experimental catalytic membrane treatment for capture and hydrodefluorination of six PFAS of regulatory concern
Article Title: New ‘hunter-killer’ chemistry captures and destroys forever chemicals
Article References: New ‘hunter-killer’ chemistry captures and destroys forever chemicals. Original publication (Bibliographic details unavailable.)
Image Credits: AI Generated
DOI: Not provided
Keywords: PFAS, water treatment, palladium catalyst, reactive hydrogen, catalytic membrane, hydrodefluorination, environmental biotechnology, water contamination, hunter-killer, chemistry, captures, destroys
