Northwestern University chemists have developed a groundbreaking process that could simplify one of the world’s toughest environmental challenges: plastic recycling.
Their new method skips the time-consuming step of sorting plastics and directly converts stubborn single-use plastics into useful products like fuels, waxes, and lubricants.
The process relies on an inexpensive nickel-based catalyst that selectively breaks down polyolefins, the plastics that make up nearly two-thirds of global consumption.
Think of everyday items like milk jugs, condiment bottles, plastic wraps, trash bags, and disposable utensils. These plastics are designed to be durable, but once discarded, they pile up in landfills and oceans, resisting degradation for decades.
Currently, recycling polyolefins is frustratingly inefficient. Mechanical recycling requires careful sorting by type, while other approaches involve heating plastics to extremely high temperatures.
These processes are costly, energy-intensive, and often yield low-quality materials. That’s why polyolefin recycling rates remain below 10% worldwide.
Catalyst cuts through the problem
Northwestern’s team turned to hydrogenolysis, a process that uses hydrogen gas and a catalyst to cut strong carbon-carbon bonds.
Instead of expensive platinum or palladium catalysts, they engineered a single-site nickel catalyst that works at lower temperatures and pressures, while also using less material.
“Compared to other nickel-based catalysts, our process uses a single-site catalyst that operates at a temperature 100 degrees lower and at half the hydrogen gas pressure,” said co-corresponding author Yosi Kratish.
“We also use 10 times less catalyst loading, and our activity is 10 times greater. So, we are winning across all categories.”
The precision design acts like a molecular scalpel, selectively targeting bonds in branched polyolefins while leaving others intact.
The result is a cleaner, more efficient chemical breakdown of mixed plastics, producing high-value oils and waxes that can be upcycled instead of downcycled.
Turning a recycling hurdle into a boost
One of the most surprising outcomes came when the catalyst encountered polyvinyl chloride (PVC), a toxic polymer notorious for making recycling impossible.
Typically, PVC contamination poisons catalysts and derails recycling batches. But in this case, PVC actually improved performance.
“Adding PVC to a recycling mixture has always been forbidden,” Kratish said. “But apparently, it makes our process even better. That is crazy. It’s definitely not something anybody expected.”
Even when PVC made up a quarter of the waste mix, the catalyst kept working with better results. This unexpected resilience could allow recyclers to tackle previously “unrecyclable” plastic streams.
Senior author Tobin Marks believes the breakthrough could transform recycling economics: “Our new catalyst could bypass this costly and labor-intensive step for common polyolefin plastics, making recycling more efficient, practical and economically viable than current strategies.”
If scaled, the nickel catalyst process might finally offer a path toward curbing the mountain of single-use plastic waste, turning a global environmental headache into a valuable resource stream.
Supported by the U.S. Department of Energy and Dow Chemical Company, the research was published in Nature Chemistry.