Images of climate innovation
Plastic: Fuel for the Future?
This image shows a plastic water bottle being turned into hydrogen fuel bubbles. The reaction is powered only by sunlight and an inexpensive, non-toxic material called a photocatalyst. As the process is scaled up from laboratory research to real-world application, it will help reduce plastic pollution, generate renewable fuel and promote a circular economy for chemicals.

With an estimated 8 million tonnes of plastic waste entering the oceans each year, it is easy to view this material as solely a source of pollution. But what if that plastic could be used to power our world instead.
To accomplish this goal, the Reisner Lab at the University of Cambridge has been developing a technology called photoreforming, which uses sunlight and a material called a photocatalyst to break down plastic waste and water into hydrogen and other useful small chemicals (https://www.youtube.com/watch?v=YkpKISv9mLY).
The process works with both pure plastics like polyethylene terephthalate (PET, code #1 on your everyday products) and waste that is not otherwise recyclable like food-contaminated plastic, microplastic fibres, and mixtures of biomass, food and plastic. The hydrogen stream generated from these waste materials is pure and can be used as a renewable fuel or a feedstock for fertilizers and other chemicals, helping to decarbonise crucial energy and chemical industries.
The photocatalysts used for photoreforming are inexpensive (no precious metals) and efficient (powered by both ultraviolet and visible sunlight), and can also be immobilised on glass panels for easy reuse, making the technology readily up-scalable. Although further improvements in efficiency are still needed, photoreforming is emerging as a renewable, versatile, and solar-powered technique for simultaneously producing emissions-free hydrogen fuel and reducing the waste in our landfills and oceans.
Entrant: Taylor Uekert , University of Cambridge
Copyright: Taylor Uekert