A REVOLUTIONARY new clean fuel has been developed that could see cars being powered by sunshine.
The environmentally clean fuel made from the power of the sun has been devised by scientists and could revolutionise motoring.
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The solar-powered technology converts carbon dioxide and water into liquid fuels that can be directly dropped into a vehicle’s engine.
The researchers from the University of Cambridge harnessed the power of photosynthesis to convert CO2, water and sunlight into multi-carbon fuels – ethanol and propanol – in a single step.
These fuels have a high energy density and can be easily stored or transported, according to scientists.
Unlike fossil fuels, these solar fuels produce net zero carbon emissions and are completely renewable – and unlike most bioethanol, they do not divert any agricultural land away from food production, experts said.
While the technology is still at laboratory scale, the researchers said their ‘artificial leaves’ are an important step in the transition away from a fossil fuel-based economy.
Dr Motiar Rahaman, the new study’s first author, said: “Shining sunlight on the artificial leaves and getting liquid fuel from carbon dioxide and water is an amazing bit of chemistry.
“Normally, when you try to convert CO2 into another chemical product using an artificial leaf device, you almost always get carbon monoxide or syngas, but here, we’ve been able to produce a practical liquid fuel just using the power of the Sun.
“It’s an exciting advance that opens up whole new avenues in our work.”
Bioethanol is often touted as a cleaner alternative to petrol, since it is made from plants instead of fossil fuels.
Most cars and trucks on the road today run on petrol containing up to 10 per cent ethanol – also known as E10 fuel.
Professor Erwin Reisner, who led the research, said: “Biofuels like ethanol are a controversial technology, not least because they take up agricultural land that could be used to grow food instead.”
The United States is the world’s largest bioethanol producer – according to the US Department of Agriculture, with almost 45 per cent of all corn grown in the USA is used for ethanol production.
Prof Reisner’s research group, based in the Yusuf Hamied Department of Chemistry, has been developing sustainable, zero-carbon fuels for several years.
The team’s research is inspired by photosynthesis – the process by which plants convert sunlight into food – using artificial leaves.
To date, these artificial leaves have only been able to make simple chemicals, such as syngas, a mixture of hydrogen and carbon monoxide that is used to produce fuels, pharmaceuticals, plastics and fertilisers, researchers said.
But to make the technology more practical, it would need to be able to produce more complex chemicals directly in a single solar-powered step.
Now the artificial leaf can directly produce clean ethanol and propanol without the need for the intermediary step of producing syngas.
So the researchers developed a copper and palladium-based catalyst, that was optimised to allow the artificial leaf to produce more complex chemicals – specifically the multi-carbon alcohols ethanol and n-propanol.
Both alcohols are high energy density fuels that can be easily transported and stored, scientists said.
Other scientists have been able to produce similar chemicals using electrical power, but this is the first time that such complex chemicals have been produced with an artificial leaf using only the energy from the Sun.
Prof Reisner, a fellow of St John’s College, Cambridge, said: “Even though there’s still work to be done, we’ve shown what these artificial leaves are capable of doing.
“It’s important to show that we can go beyond the simplest molecules and make things that are directly useful as we transition away from fossil fuels.”
Currently the device is a ‘proof of concept’ and shows only modest efficiency, the study authors added.
Researchers are working to optimise the light absorbers so that they can better absorb sunlight and optimising the catalyst so it can convert more sunlight into fuel.
Further work will also be needed so the device can be mass produced and make large volumes of fuel.
The results of the study were reported in the journal Nature Energy.
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