Researchers from Lawrence Berkeley National Laboratory found that a copper catalyst can help to economically recycle carbon dioxide into valuable chemicals and fuels
A team of researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Joint Center for Artificial Photosynthesis (JCAP) found that a single copper catalyst can help for economical and efficient recycle of carbon dioxide into valuable chemicals and fuels. The surface of copper metal appears bumpy at the microscopic level and these bumps are dubbed as ‘active sites’. These active sites are a place for electrocatalysis in copper. Electrons from the copper surface interact with carbon dioxide and water in a sequential steps to transform carbon dioxide into products such as ethanol fuel, ethylene, and propanol.
Previous studies assumed that copper’s active sites were not product-specific as copper could be used as a catalyst for making ethanol, ethylene, propanol, or some other carbon-based chemical. The process did not require to separate unwanted, residual chemicals that were formed during the intermediate stages of a chemical reaction before formation of the chemical end-product. The team was focused on investigating copper’s catalytic properties for a solar fuels project. The team theorized the use of electrons from solar cells to drive specific active sites of a copper catalyst in order to develop a pure product stream of a carbon-based fuel or chemical. Oxidized copper is an excellent catalyst for making ethanol, ethylene, and propanol. The team proposed that product-specific active sites in copper can help to trace origins of the chemicals through carbon isotopes.
The team performed experiments with two isotopes of carbon: carbon-12 and carbon-13. Carbon dioxide was labeled with carbon-12 and carbon monoxide was labeled with carbon-13. The team reasoned that the ratio of carbon-13 against carbon-12 found in a product can help to determine the origin of the chemical product. Mass spectrometry and Nuclear Magnetic Resonance (NMR) spectroscopy was used to analyze the results and the researchers found that three of the products — ethylene, ethanol, and propanol – demonstrated different isotopic signatures indicating that the products originated from different sites on the catalyst. The research was published in the journal Nature Catalysis on December 17, 2018.