Energy breakthrough converts plastic waste into clean fuels

Plastics made life easier, but their durability created a global problem. Bags, bottles, and films last for centuries, breaking into microplastics that infiltrate soil, water, and even the air. These particles enter food chains and pose health risks.

Recycling was supposed to help, yet every cycle makes plastics weaker and less useful. Meanwhile, production keeps rising. The balance tilts toward waste, and scientists know recycling alone will never catch up.

From plastic waste to fuel

At the University of Delaware, researchers tried a new angle. Instead of simply recycling, they looked at plastics as potential fuel. Their work, published in Chem Catalysis, demonstrates a catalyst that speeds up the conversion of plastics into liquid fuels. The process also produces fewer unwanted byproducts.

The study’s senior author is Dongxia Liu, a professor of chemical and biomolecular engineering at the University of Delaware.

“Instead of letting plastics pile up as waste, upcycling treats them like solid fuels that can be transformed into useful liquid fuels and chemicals, offering a faster, more efficient, and environmentally friendly solution,” she said.

Hydrogen power for plastics

One approach stands out: hydrogenolysis. It uses hydrogen gas and a catalyst to chop up polymers. The result can be fuels for transport or industry, offering a way to turn stubborn waste into something useful. Conventional catalysts, though, struggle with this process.

Plastic molecules are large and tangled, making it difficult for them to fit into the tiny spaces where reactions occur. That limited contact slows the reaction and often leads to the incomplete breakdown of plastic.

It also reduces efficiency and produces unwanted byproducts, such as gases that add to environmental concerns. For scientists, the challenge was to design a system that could let polymers interact more freely with catalysts.

The Delaware group turned to MXenes – nanomaterials with a layered structure. MXenes are thin, sheet-like materials that normally stack tightly together, restricting flow. By rethinking this structure, the team gave MXenes a twist that opened the way for faster and cleaner plastic conversion.

More space, better contact

“MXenes form two-dimensional layers, like the pages of a book. These stacked layers in the closed book make it difficult for molten plastic to move through easily, limiting contact with the catalyst,” said first author Ali Kamali, a doctoral candidate.

The team inserted silica pillars to hold the layers apart, creating mesoporous MXenes. Now polymers and intermediate compounds could slip through the spaces and interact with the catalyst more effectively.

Testing plastic waste for fuel

To prove the idea, the group worked with low-density polyethylene (LDPE), the plastic used in bags and wraps. Inside a pressurized reactor, LDPE was mixed with hydrogen gas and the mesoporous MXene-supported ruthenium catalyst.

Heat turned the plastic into a syrup-like liquid, which then reacted. Results showed conversion rates nearly twice as fast as earlier LDPE hydrogenolysis studies. The catalyst also guided the reaction toward liquid fuels instead of waste gases like methane.

Stable design, cleaner fuel

The open MXene structure stabilized ruthenium nanoparticles, keeping them active and selective. This stability meant faster conversion and cleaner products.

“We were able to produce a material that not only speeds the conversion but also improves the quality of the fuel products. This advance highlights the potential of nanostructured mesoporous catalysts to enhance plastic upcycling,” Liu said.

The outcome shows how careful design at the nanoscale can reshape the performance of everyday processes and open new possibilities for sustainable technologies.

Building on this foundation, the Delaware team now plans to refine the catalyst and develop new versions tailored to different plastics, while also working with industrial partners to scale the process.

Their long-term vision is ambitious yet practical: transforming discarded plastics into fuels and valuable chemicals that support communities and reduce pollution.

Plastics powering the future

Plastics have long symbolized waste. Research like this suggests they could become resources. If mesoporous MXene catalysts scale beyond the lab, discarded bags and films may feed the energy supply instead of choking rivers and landscapes.

The path from plastic waste to fuel is still in progress, but the idea itself changes how we look at plastics.

This work involved experts from the University of Maryland, Oak Ridge National Laboratory, the U.S. Army Combat Capabilities Development Command Army Research Laboratory, and the National Institute of Standards and Technology.

By linking expertise across institutions, the project shows how difficult problems demand shared solutions.

The study is published in the journal Chem Catalysis.

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