A promising avenue for the future of clean energy is to store it in the form of carbon-based fuels produced from renewable sources, effectively enabling the clean use of liquid fuels such as gasoline.
A first step is the electrolysis of carbon dioxide into oxygen and carbon monoxide, which can be subsequently be transformed into liquid fuels. But current CO-forming catalysts are either not selective enough or too expensive to be industrially viable.
EPFL scientists have now developed an Earth-abundant catalyst based on copper-oxide nanowires modified with tin oxide. A solar-driven system set up using this catalyst was able to split CO2 with an efficiency of 13.4%. The work is published in Nature Energy, and is expected to help worldwide efforts to synthetically produce carbon-based fuels from CO2 and water.
The research was carried out by the lab of Michael Grätzel at EPFL. Grätzel is known worldwide for the invention of dye-sensitized solar cells (“Grätzel cells”). The new catalyst, developed by PhD student Marcel Schreier, postdoc Jingshan Luo, and several co-workers, is made by depositing atomic layers of tin oxide on copper oxide nanowires. Tin oxide suppresses the generation of side-products, which are commonly observed from copper oxide catalysts, leading to the sole production of CO in the electroreduction of CO2.
The catalyst was integrated into a CO2 electrolysis system and linked to a triple-junction solar cell (GaInP/GaInAs/Ge) to make a CO2 photo-electrolyzer. Importantly, the system uses the same catalyst as the cathode that reduces CO2 to CO and the anode that oxidizes water to oxygen through what is known as the “oxygen evolution reaction”. The gases are separated with a bipolar membrane. Using only Earth-abundant materials to catalyze both reactions, this design keeps the cost of the system low.
The system was able to selectively convert CO2 to CO with an efficiency of 13.4% using solar energy. The catalyst also reached a Faradaic efficiency of up to 90%, which describes how efficiently electrical charge is transferred to the desired product in an electrocatalysis system like the one developed here. “The work sets a new benchmark for solar-driven CO2 reduction,” says Luo.
“This is the first time that such a bi-functional and low-cost catalyst is demonstrated,” adds Schreier. “Very few catalysts — except expensive ones, like gold and silver — can selectively transform CO2 to CO in water, which is crucial for industrial applications.”
The Latest on: Splitting CO2 into CO and oxygen
- Wärtsilä is in search of start-ups with Power-to-X technology to join SparkUp Challenge on September 19, 2018 at 10:47 am
We are especially interested in Power-to-Gas solutions e.g. where electricity is used to split water into hydrogen and oxygen by means of electrolysis, or solutions where we combine hydrogen from an e... […]
- Gold Nanomaterials Make Photoelectrode Shine Bright on September 18, 2018 at 1:30 pm
Artificial photosynthesis is used to either split water molecules into hydrogen and oxygen or reduce carbon dioxide. Last year, we visited the U.S. Department of Energy’s Joint Center for ... […]
- After 150 Years, We Finally Had a Breakthrough Toward Turning CO2 Into Fuel on September 17, 2018 at 12:07 pm
For a century and a half or more, researchers have been trying to figure out how to do something useful with all the carbon dioxide floating ... more efficiently split water molecules into hydrogen (w... […]
- S, N co-doped carbon nanotube-encapsulated [email protected]: Efficient and stable catalysts for water splitting on September 10, 2018 at 10:52 am
To address this issue, encapsulation of Co ... into the carbon nanotubes framework. The obtained materials (S, exhibit excellent HER and OER performance. As cathode and anode, S, can rapidly dissociat... […]
- Researchers set new bar for water-splitting, CO2-splitting techniques on August 30, 2017 at 11:03 am
Researchers from North Carolina State University have significantly boosted the efficiency of two techniques, for splitting water to create hydrogen gas and splitting carbon dioxide ... CO 2 into CO. ... […]
via Google News and Bing News