A new nickel-based catalyst developed by scientists at Northwestern University could mark a major turning point for global plastic recycling, offering a practical solution to one of the industry’s most persistent challenges: mixed plastic waste.
The research team has introduced an innovative recycling process that eliminates the need for labor-intensive sorting by selectively breaking down polyolefin plastics—such as polyethylene and polypropylene—into valuable liquid products. These plastics account for nearly two-thirds of global plastic consumption and are widely used in single-use items including packaging, containers, and disposable household goods.
Published on September 2, 2025, in Nature Chemistry, the study demonstrates how an inexpensive, earth-abundant nickel catalyst can convert low-value plastic waste into oils, waxes, fuels, and lubricants, significantly improving the economics of plastic recycling.
Moving Beyond Costly Sorting
One of the biggest obstacles in recycling polyolefins has been their chemical stability. Their strong carbon–carbon bonds make them difficult to break down, forcing recyclers to rely on sorting, downcycling, or energy-intensive thermal processes.
“Our new catalyst could bypass the costly and labor-intensive sorting step for common polyolefin plastics,” said Tobin Marks, senior author of the study and professor of catalytic chemistry at Northwestern University. “This makes recycling far more efficient and commercially viable.”
Unlike existing approaches that require extremely high temperatures or expensive noble metals such as platinum or palladium, the new process uses a single-site organo-nickel catalyst that operates at lower temperatures, with less hydrogen pressure, and significantly reduced catalyst loading—while delivering higher performance.
Turning Waste into Value
When applied to mixed polyolefin waste, the catalyst breaks down solid plastics into liquid hydrocarbons, which can be upgraded into higher-value industrial products. The catalyst is also reusable and maintains stability over multiple cycles.
In a particularly unexpected result, the catalyst remained effective—even improved in performance—when exposed to polyvinyl chloride (PVC) contamination. PVC typically releases corrosive byproducts during recycling and is a major reason mixed plastic waste is often deemed unrecyclable.
Tests showed the catalyst continued to function even when PVC accounted for up to 25 percent of the plastic mixture, suggesting a pathway to recycling waste streams previously considered unusable.
Nickel’s Role in the Circular Economy
According to co-author Yosi Kratish, the decision to use nickel was driven by both scale and availability.
“Polyolefin production is massive, but global supplies of noble metals are limited,” Kratish said. “Nickel is abundant, affordable, and scalable—making it far better suited for addressing the global plastic problem.”
The catalyst’s single-site molecular design allows it to selectively target specific bonds, enabling chemical separation within mixed plastics and greater control over the end products.
Implications for Industry
With global polyolefin recycling rates estimated at below 10 percent, the technology could significantly advance circular economy strategies, reduce landfill waste, and lower dependence on virgin petrochemical feedstocks.
The findings point to a growing role for nickel-based technologies beyond batteries and stainless steel—extending into advanced recycling, sustainability, and materials innovation.
The study was supported by the U.S. Department of Energy and The Dow Chemical Company, highlighting strong industrial interest in scalable solutions for plastic waste.
