Two-in-one — this is one way to describe a new material developed by an international team of scientists including researchers from the Centre for Energy and Environmental Technologies at VSB – Technical University of Ostrava (CEET) and CATRIN at Palacký University. This versatile material, based on iron and carbon atoms, can not only convert plastic waste into useful products, but also reduce the cost of manufacturing important chemicals and pharmaceuticals. The researchers recently published their findings in the prestigious journal Nature Catalysis and are now planning to scale up production to a pilot-plant level.
The scientists set out to help address one of today’s most pressing challenges: plastic recycling. They focused on polystyrene, global production of which exceeds 20 million tonnes annually, while only a negligible fraction – approximately one to three percent – is currently recycled. Existing recycling methods are either inefficient or technologically complex and environmentally unfriendly.
“Mechanical recycling of polystyrene leads to deterioration in product quality and limits its further applications. Pyrolysis is energy-intensive, requires very high temperatures, and the resulting chemical mixture must be purified through complex processes. That is why we developed an environmentally friendly low-temperature technology which, with the help of oxygen and ammonia, enables the production of benzonitrile. This is a highly valuable chemical used as a key building block in the production of pharmaceuticals, fertilizers, and other industrial chemicals,” said Radek Zbořil, one of the lead authors of the study affiliated with CEET and CATRIN.
However, converting polystyrene and other organic compounds into nitriles is highly challenging because their chemical bonds are stable and difficult to break. The key to success was therefore the development of an efficient catalyst capable of lowering reaction temperatures while increasing the yield of the target product.
“The catalyst is based on iron atoms dispersed within a carbon support and stabilized by nitrogen and boron atoms. This specific chemical environment surrounding the atomic iron, together with the porous structure of the support, is essential for achieving efficient low-temperature conversion of polystyrene. The material can be easily produced on a large scale and, once the chemical process is completed, it can be recycled and reused. These factors are crucial for the advancement of industrial processes,” explained Jagadeesh Rajenahally, another corresponding author affiliated with CEET and the Leibniz Institute for Catalysis in Rostock, Germany.
The applications of the new catalyst extend far beyond polystyrene. It can also efficiently convert dozens of organic compounds into valuable nitriles used in chemistry and pharmaceuticals, for example in the production of antidepressants and diabetes medications. Its versatility, ease of production, lower energy consumption, and the significant cost reduction it offers for many chemical processes are expected to accelerate its adoption in industry. The scientists are therefore planning to scale up production to a pilot operation.
“The atomic catalyst is remarkably versatile. We successfully used it in the synthesis of around 60 valuable nitrile-based chemicals utilized in pharmaceuticals and industrial chemistry. We operate at significantly lower temperatures than current industrial production methods, and thanks to the controlled reaction pathway, we generate only minimal amounts of waste by-products. In a flow reactor, we demonstrated the material’s stability over many days during polystyrene conversion, which are very promising results for transferring the technology into practical applications,” Zbořil concluded.
