Soundwave recycling technology turns ‘forever chemicals’ into renewable resources

A new technique that uses soundwaves to separate materials for recycling could help prevent potentially harmful chemicals leaching into the environment.

Researchers at the University of Leicester have achieved a major milestone in fuel cell recycling, advancing techniques to efficiently separate valuable catalyst materials and fluorinated polymer membranes (PFAS) from catalyst-coated membranes (CCMs). The articles are published in RSC Sustainability and Ultrasonic Sonochemistry.

This development addresses critical environmental challenges posed by PFAS—often referred to as “forever chemicals”—which are known to contaminate drinking water and have serious health implications. The Royal Society of Chemistry has urged government intervention to reduce PFAS levels in UK water supplies.

Fuel cells and water electrolyzers, essential components of hydrogen-powered energy systems, powering cars, trains and buses, depend on CCMs containing precious platinum group metals. However, the strong adhesion between catalyst layers and PFAS membranes has made recycling difficult.

Researchers at Leicester have developed a scalable method using organic solvent soaking and water ultrasonication to effectively separate these materials, revolutionizing the recycling process.

Dr. Jake Yang from the University of Leicester School of Chemistry said, “This method is simple and scalable. We can now separate PFAS membranes from precious metals without harsh chemicals—revolutionizing how we recycle fuel cells.

“Fuel cells have been heralded for a long time as the breakthrough technology for clean energy but the high cost of platinum group metals has been seen as a limitation. A circular economy in these metals will bring this breakthrough technology one step closer to reality.”

Building on this success, a follow-up study introduced a continuous delamination process, using a bespoke blade sonotrode that uses high frequency ultrasound to split the membranes to accelerate recycling. The process creates bubbles that collapse when subjected to high pressure, meaning the precious catalysts can be separated in seconds at room temperature. The innovative process is both sustainable and economically viable, paving the way for widespread adoption.

This research was carried out in collaboration with Johnson Matthey, a global leader in sustainable technologies. Industry-academia partnerships such as this underscore the importance of collective efforts in driving technological progress.

Ross Gordon, Principal Research Scientist at Johnson Matthey, said, “The development of high-intensity ultrasound to separate catalyst-loaded membranes is a game-changer in how we approach fuel cell recycling. At Johnson Matthey, we are proud to collaborate on pioneering solutions that accelerate the adoption of hydrogen-powered energy while making it more sustainable and economically viable.”

As fuel cell demand continues to grow, this breakthrough contributes to the circular economy by enabling efficient recycling of essential clean energy components. The researchers’ efforts support a greener and more affordable future for fuel cell technology while addressing pressing environmental challenges.