By Neetika Walter
Researchers at the University of Chicago Pritzker School of Molecular Engineering have found a new way to break down the stubborn water pollutants known as per- and polyfluoroalkyl substances, or PFAS.
The team, led by Asst. Prof. Chibueze Amanchukwu, spent three years studying battery failures. They looked for compounds that degrade in batteries and asked whether the same chemistry could break down PFAS.
Working with Northwestern University researchers, the team turned conditions that degrade battery components into a method for destroying PFAS.
The new approach breaks the long-chain PFAS molecule perfluorooctanoic acid, or PFOA, into mineralized fluorine without forming shorter molecules that are harder to remove.
Flipping battery chemistry
“We achieve about 94 percent defluorination and 95 percent degradation. That means we break nearly all the carbon–fluorine bonds in PFAS,” said first author Bidushi Sarkar, a UChicago PME postdoctoral researcher.
“We are mainly mineralizing and pushing complete breakdown of PFAS instead of just chopping it into shorter fragments.”
The process uses lithium-mediated electroreduction in non-aqueous electrolytes. It avoids oxidizing the compounds, which is difficult because fluorine strongly attracts electrons.
Fluorinated compounds usually degrade water instead of themselves when reduced. The team solved this by using non-aqueous solvents with high reductive stability and treating copper electrodes with lithium.
“This work is novel in its thoughtful use of lithium‑mediated electroreduction, instead of the more common oxidative pathways, to achieve high PFOA conversion and near-complete defluorination in a non-aqueous system without generating shorter-chain PFAS byproducts,” said University of Illinois Chicago Prof. Brian Chaplin, who was not involved in the research.
Modular and site-ready
PFAS are called forever chemicals because of the strong carbon-fluorine bonds that make them fire, water, and oil resistant. Their durability also makes them nearly impossible to remove from water.
“The reason people love electrochemistry is that it is quite modular,” Amanchukwu said.
“I can have a solar panel with batteries, and I can have an electrochemical reactor on site that is small enough to deal with any local waste streams. You don’t need a large plant that operates at high temperatures or high pressures, which are in some of the systems that people are trying to build today.”
Of the 33 PFAS compounds tested, 22 showed degradation above 70 percent, with some reaching 99 percent.
The research was supported by the Advanced Materials for Energy-Water Systems Center, an Energy Frontier Research Center led by Argonne National Laboratory.
“This has been an exciting outcome associated with the AMEWS Center,” said co-author Northwestern University Prof. George Schatz.
“The intention is to try to get scientists to interact with each other who might not normally interact.”
The work shows a practical, modular way to tackle PFAS contamination and may inspire future methods that turn pollutants into valuable products.
The study appears in Nature Chemistry.
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