Simple catalysts recycle mixed plastics

A pair of robust and inexpensive catalysts can help recycle mixtures of polyethylene (PE) and polypropylene (PP), two of the most common and intractable types of plastic waste ( Science 2024, DOI: 10.1126 /science.adq7316 ). The catalysts chop up the polymers and combine them with ethene to produce propene and isobutene , which can be used to make new plastics. Although the lab-based process still faces many hurdles before becoming a practical industrial system, it shows how chemical recycling could address some of the most difficult challenges in tackling waste plastic, says John F. Hartwig of the University of California, Berkeley, who led the team. “The fact that they have simple catalysts that could potentially be robust in a realistic process is very important,” says Susannah L. Scott of the University of California, Santa Barbara, who works on similar polymer recycling processes and was not involved in the study. Various