Plastic has become an inseparable part of modern life—from water bottles to polyester clothing.
But did you know that over half of all plastic ever produced was made after the year 2000? And unfortunately, only around 9% has ever been recycled. The rest ends up in landfills, pollutes our oceans, or breaks down into microplastics that infiltrate the human body.
The United States has even been identified as the world’s highest per capita plastic polluter. Ironically, only 5% of all plastic in the U.S. is successfully recycled—a clear indication that current recycling methods are far from effective.
An Unexpected Solution
Now, a team of scientists from Northwestern University has unveiled a breakthrough that is both surprising and promising. Imagine being able to break down plastic using nothing but the air around us. It may sound like magic—but it's very real.
The research team developed a new method to decompose plastic using natural moisture in the air. Yes—just a trace amount of atmospheric humidity, without any harmful solvents, high energy input, or toxic waste.
The Secret Behind the Process
The key lies in two relatively cheap and accessible materials: molybdenum-based catalyst and activated carbon. This catalyst breaks the chemical bonds in PET plastic (polyethylene terephthalate)—the kind used in beverage bottles and polyester fabrics.
What makes this breakthrough especially remarkable is the choice of catalyst. Traditional chemical recycling methods typically rely on expensive and toxic metals like platinum or palladium, which are not only costly but also produce hazardous byproducts.
In contrast, the Northwestern team chose molybdenum—a metal that is far cheaper, more abundant, and non-toxic. This makes the process not only more environmentally friendly, but also economically viable for large-scale adoption.
Turning Plastic into Valuable Material
Once the plastic is heated together with the molybdenum catalyst and activated carbon, the next step is surprisingly simple: expose it to air. In just four hours, 94% of the plastic is converted into terephthalic acid (TPA)—a high-value chemical compound that serves as a primary building block for making new polyester.
What’s more, the process is highly selective. It specifically targets polyester-based plastics, eliminating the need for pre-sorting. Even colorful or mixed plastics, such as clothing or household waste, can be broken down into pure, colorless TPA.
Why This Matters
In conventional recycling, plastic is typically melted down and turned into lower-quality products—a process known as downcycling. Moreover, traditional methods often require extreme heat, toxic chemicals, and generate additional waste.
The Northwestern technology is fundamentally different. There are no solvents, no hazardous byproducts—in fact, the only byproduct of this reaction is acetaldehyde, an industrially valuable compound that is easy to isolate and reuse.
What’s more, the catalyst used in the process can be reused multiple times without losing its effectiveness. This makes the method not only efficient and environmentally friendly, but also viable for industrial-scale implementation.
Toward a More Realized Circular Economy
With this technology, scientists believe we can take a significant step toward a true circular economy—where materials are not discarded but continuously reused.
The TPA produced through this process can be used to make new plastic or even upcycled into higher-value materials.
This innovation also helps tackle global challenges: reducing dependency on virgin raw materials, cutting waste, and lowering carbon emissions.
Challenges and the Road Ahead
Despite the promising results, challenges remain: how can this process be optimized for industrial-scale operations? The team at Northwestern is now working on scaling up the process to handle larger volumes of plastic waste.
Still, the approach they’ve developed offers a new sense of hope—that we can use smart, low-cost, and environmentally friendly chemistry to solve one of the most urgent problems of our century.
Source: Naveen Malik et al, Thermodynamically leveraged solventless aerobic deconstruction of polyethylene-terephthalate plastics over a single-site molybdenum-dioxo catalyst, Green Chemistry (2025). DOI: 10.1039/D4GC05916F
