S cientists have discovered a new method for splitting carbon dioxide in what could prove to be a major leap forward in mass-producing renewable energy. The process is carbon-neutral and efficient, using a low-cost copper catalyst in a process driven by solar power.
The splitting process was already a well-known way of producing fuel without increasing the level of carbon dioxide in the atmosphere. Once carbon dioxide is split into carbon monoxide and oxygen, the carbon monoxide can be combined with hydrogen to make synthetic carbon-based fuel. Using solar power for the process means CO2 is taken out of the atmosphere without any being put back in, and clean fuel is produced, a win-win scenario from an environmental point of view.
Until now, though, such carbon-neutral methods had been prohibitively expensive. Other methods required more expensive precious metals as catalysts, such as gold, silver and palladium.
A team of Swiss scientists from the the École Polytechnique Fédérale de Lausanne (EPFL) developed the new system, which splits carbon dioxide with an efficiency of 13.4%. “It’s the highest value that has been reported,” said Marcel Schreier, a chemical engineer and lead author on the EPFL study.
This was not the only progress. Existing methods often risked producing a number of unwanted byproducts due to the reaction of carbon dioxide with water. But the device uses a current running through copper oxide wires, which, once coated with extremely thin layers of tin oxide, both keeps the generation of byproducts to a minimum and maximises carbon monoxide production to boot.
The new system is not quite revolutionary, though - yet. The activity of the materials it uses is still relatively low compared to what can be managed with precious metals, meaning that the new process is some way from being industrially viable.
Still, the Swiss team is optimistic. "The work sets a new benchmark for solar-driven CO2 reduction," said Jingshan Luo, one of Mr. Schreier’s colleagues. Applications include the hydrogen-fueled car market, currently hampered by the challenge of storing and transporting gas. Mr. Schreier hopes liquid fuels from carbon monoxide could overcome this hurdle, taking us one step closer to closing the “anthropogenic carbon cycle”.