Two-step system makes plastic from carbon dioxide, water and electricity

Summary

Credit: Angewandte Chemie International Edition (2025). DOI: 10.1002/anie.202503003 What if a machine could suck up carbon dioxide from the atmosphere, run it through a series of chemical reactions, and essentially spit out industrially useful plastic? "I think that is something that we, as a society, would be interested in. After all, in addition to being a greenhouse gas, carbon dioxide is an abundant and inexpensive feedstock," says Theo Agapie, Ph.D., the John Stauffer Professor of Chemistry and the executive officer for chemistry at Caltech. "With our new work, we have taken a significant step in that direction." Reporting in the journal Angewandte Chemie International Edition, Agapie and a team of Caltech chemists have developed a system that uses electricity from sustainable sources to carry out the chemical conversion of carbon dioxide (CO2) into molecules, such as ethylene and carbon monoxide, that are useful for making more complex compounds. When this is accomplished using light as the energy source, without plants, such a process is known as artificial photosynthesis. The new system feeds the ethylene and carbon monoxide that have been generated into a second catalytic loop that yields industrially useful plastics called polyketones, which are known for their strength, durability, and thermal stability, making them ideal for applications ranging from adhesives to car parts and from sports equipment to industrial piping. "We have shown that one can use CO2 to make a material that is useful, without using plants as a mediator," says lead author Max Zhelyabovskiy, a graduate student in Agapie's lab who was co-mentored on the project by Jonas C. Peters, Caltech's Bren Professor of Chemistry and director of the Resnick Sustainability Institute. The Caltech-led team is not the first to build a system that attempts to pair CO2 reduction with a second chemical reaction to ultimately produce polymers. But previous systems have added ethylene that comes from petro...