Artificial leaf with copper nanostructure produces complex hydrocarbons
A system inspired by photosynthesis is to be used to produce synthetic fuels. It also provides valuable by-products.
(Image: Virgil Andrei)
Hydrocarbons for synthetic fuels: A British-American team has developed an artificial leaf that uses sunlight to convert carbon dioxide into more complex hydrocarbons.
The system is based on earlier work with artificial leaves by the Cambridge researchers, which produced synthesis gas from carbon dioxide and water. "We wanted to go beyond simple carbon dioxide reduction and produce more complex hydrocarbons, but this requires much more energy," said Virgil Andrei.
This energy is supplied by a perovskite solar cell. The researchers use copper nanoflowers as a catalyst. These enable the production of molecules with two carbon atoms, such as ethane and ethylene. Other metal catalysts could only convert carbon dioxide into molecules with one carbon atom.
Glycerol improves efficiency
To improve the efficiency of the system, the researchers have replaced the water with glycerine, which is oxidized by electrodes made of silicon nanowire. This makes the system 200 times more efficient than one that uses water. It also produces by-products such as glyceric acid or lactate, which in turn are used in the cosmetics and pharmaceutical industries.
Glycerol is normally considered a waste product, said Andrei. "But here it plays an important role by improving the reaction rate." This means that the system can be used for various applications. "By carefully designing the surface of the catalyst, we can influence which products we produce."
Ethane and ethylene are important raw materials in the chemical industry, for example for the production of synthetic fuels or plastics. They are currently mainly obtained from fossil sources. Photoelectrochemistry (PEC) could be a sustainable alternative to the production of hydrocarbons from small building blocks such as carbon dioxide or water, the researchers write in the journal Nature Catalysis
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The efficiency of the system is currently only ten percent. However, the team is optimistic that improvements are still possible.
(wpl)
