US researchers have discovered a new electrocatalyst that converts carbon dioxide (CO2) and water into ethanol with very high energy efficiency, high selectivity for the desired final product and low cost.
Led by the US Department of Energy’s (DOE) Argonne National Laboratory in collaboration with Northern Illinois University, the research teams process electrochemically converts the carbon dioxide emitted from industrial processes, such as fossil fuel power plants or alcohol fermentation plants, into valuable commodities at reasonable cost.
Ethanol is a particularly desirable commodity because it is an ingredient in nearly all US gasoline and is widely used as an intermediate product in the chemical, pharmaceutical and cosmetics industries.
“The process resulting from our catalyst would contribute to the circular carbon economy, which entails the reuse of carbon dioxide,” said Di-Jia Liu, Senior Chemist in Argonne’s Chemical Sciences and Engineering division and a UChicago CASE scientist in the Pritzker School of Molecular Engineering, University of Chicago.
The team’s catalyst consists of atomically dispersed copper on a carbon-powder support. By an electrochemical reaction, this catalyst breaks down carbon dioxide and water molecules and selectively reassembles the broken molecules into ethanol under an external electric field.
The research team said the electrocatalytic selectivity, or “Faradaic efficiency,” of the process is over 90%, much higher than any other reported process.
What is more, the catalyst operates stably over extended operation at low voltage.
“With this research, we’ve discovered a new catalytic mechanism for converting carbon dioxide and water into ethanol,” said Tao Xu, a Professor in physical chemistry and nanotechnology from Northern Illinois University.
“The mechanism should also provide a foundation for development of highly efficient electrocatalysts for carbon dioxide conversion to a vast array of value-added chemicals.”