# Palladium membrane fed with hydrogen defluorinates six PFAS at room temperature in lab tests

- Published: 2026-11-15 18:43 UTC
- Section: Science › Chemistry
- Tags: forever chemicals, PFAS destruction, palladium hydride, catalytic membrane, defluorination, PFOA, PFOS, GenX, Arizona State University, water treatment
- URL: https://realtech.media/news/rt-e02d5f1dd86373b9a9d0903b_palladium_membrane_fed/

**A hydrogen-fed palladium catalytic membrane converted PFOA, PFOS, PFNA, PFHxS, PFBS and GenX toward defluorinated products; the tests used lab-mixed water.**

![Palladium membrane fed with hydrogen defluorinates six PFAS at room temperature in lab tests](https://realtech.media/media/2026/11/fb2a2b7269b1dbed.jpg)
*Earth.com*

A team led by Bruce Rittmann of the Biodesign Swette Center for Environmental Biotechnology at Arizona State University, with Min Long and Jie Cheng, built a catalytic membrane that destroys PFAS at ambient conditions, according to a paper in Proceedings of the National Academy of Sciences [1]. Colleagues at Rice University, the National University of Singapore and two universities in China took part. In a continuous test of 58 days, with six PFAS fed together, removal reached up to 96% and defluorination 83% [1].

## How the hydrogen membrane works

The reactor is a glass vessel about 30 centimeters long. It holds 120 hollow plastic fibers coated with a palladium film. Hydrogen gas is pumped into the hollow core of each fiber and reaches the palladium from underneath, while the contaminated water sits against the outside.

Palladium splits hydrogen molecules into atoms. Some stay on the metal surface, and others are stored inside as β-phase palladium hydride, which expands the lattice; the metal swells by about 4 percent as it fills [1]. The two forms do different jobs. Surface hydrogen helps the membrane capture a PFAS molecule, while hydrogen stored inside supplies the driving force for stepwise hydrodefluorination, consistent with sequential C–F bond scission [1].

In control runs, hydrogen without palladium did nothing to PFOA. Palladium without hydrogen removed about 30 percent of the PFOA but released no fluoride. Feeding hydrogen through the fibers doubled the fluoride release compared with feeding it into the air space above the water, while PFOA left the water at about the same rate.

## Results for six PFAS

Across PFOA, PFOS, PFNA, PFHxS, PFBS and GenX, the membrane converted all contaminants toward fully defluorinated products [1]. In 44-hour batch tests at pH 4, longer chains were removed and defluorinated faster. PFNA, with nine carbons, lost 59 percent of its fluorine, and four-carbon PFBS lost 26 percent.

GenX was more resistant because of its ether linkage, weaker adsorption and higher average C–F bond dissociation energy. It still showed removal and defluorination, with 2-propoxypropanoic acid formed [1]. About 27 percent of its fluorine came off. A commercial palladium-on-carbon catalyst removed about 85 percent of the PFOA but freed 37 percent of the fluorine, against 51 percent for the membrane film.

The long test used 50 micrograms per liter of each compound, mixed in the lab. The team reports no test on water from a real contaminated site, and the water did not reach the EPA drinking-water limits in any run. About 10 percent of the palladium was lost over the run. The group is scaling up the reactor for pilot tests.

## Sources

1. [Proceedings of the National Academy of Sciences](https://doi.org/10.1073/pnas.2613985123)
2. [Earth.com](https://www.earth.com/environment/forever-chemicals-are-supposed-to-be-unbreakable-but-new-hunter-killer-chemistry-takes-them-out)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-e02d5f1dd86373b9a9d0903b_palladium_membrane_fed/