A new use for old refrigerants

Iridium chemistry in action

Chemicals in air conditioners are thousands of times more dangerous for the environment than tailpipe emissions from cars. Researchers at Lehigh University are working to change that.

David Vicic, Howard S. Bunn Distinguished Professor of Chemistry at Lehigh University, recently announced a breakthrough in chemical research: His team used the metal iridium to functionalize hydrofluorocarbon refrigerants – the ubiquitous chemicals that cool refrigerators, medicines, homes, and office buildings. The peer-reviewed article, “Identifying Reactivity Differences of Two-Carbon-Atom-Based Legacy Refrigerants at Group 9 Metal Pincer Complexes”, was published open-access (free-to-read) by the American Chemical Society.

The work is being conducted as part of EARTH, the Environmentally Applied Refrigerant Technology Hub, an Engineering Research Center funded by the National Science Foundation. EARTH is led by the University of Kansas and also involves professors, staff and students from Lehigh University, University of Notre Dame, University of Maryland, University of Hawai’i, and University of South Dakota.

Using iridium as a catalyst in chemical processes could, one day, turn greenhouse gases in old air conditioners into raw materials for use in pharmaceutical, solar, and other industries. Doing so contributes to EARTH's mission to build a circular economy for refrigerants, which is good for the planet, business and the public.

“The discovery is significant not only for commercial reasons but also because refrigerants pose a threat to the atmosphere,” Vicic says. “The target chemical compounds will help reduce the adverse effects that refrigerants have on the environment.”

Todd Watkins, an economics professor at Lehigh who is also a member of EARTH’s leadership team, said the innovation is relevant to the business needs of some of the companies that are members of EARTH’s industry consortium.

"By demonstrating a novel way to selectively activate and functionalize different legacy refrigerants, the research opens a potential pathway toward a circular economy for  hydrofluorocarbons,” said Watkins, who is also Executive Director of Lehigh’s Martindale Center for the Study of Private Enterprise. 

“If we can scale up these reactions into practical cost-effective industrial processes, we could not just remove them but reuse them, turning a major environmental liability into valuable chemical building blocks."

The Vicic lab’s work has several commercial applications, said EARTH Innovation Officer Tony von Sadovszky.

“These include greenhouse gas mitigation through chemical upcycling, repurposing phased-out refrigerants into specialty fluorochemicals, and the development of new methods and technologies to reduce or remove per- and polyfluoroalkyl substances (PFAS) from water,” he said. 

Members of EARTH’s industry consortium are welcome to contact Tony von Sadovszky at tvs@ku.edu if they are interested in licensing the new technology. 

Acknowledgement

This research is based upon work supported by the National Science Foundation under award number ERC-2330175 for the Engineering Research Center EARTH (for authors D.A.V. and L.A.F.). The authors would like to thank Chemours for gracious donations of R-143a, R-134a, and R-125. The authors would like to thank Wendy Breyer for help with configuration and execution of NMR experiments. The authors thank Robert Syvret for helpful discussions. R.P.H. is grateful to Dartmouth College Research Computing for consulting expertise and financial assistance with hardware and software resources.