Accidental discovery turns carbon dioxide into ethanol fuel

Scientists at the Oak Ridge National Laboratory have accidentally discovered a process by which they are able to convert the greenhouse gas carbon dioxide into ethanol that can be used for fuel. The electrochemical process uses tiny spikes of carbon and copper in the conversion process. In addition to the carbon and copper, the process also requires nitrogen and an applied voltage.

"We discovered somewhat by accident that this material worked," said ORNL's Adam Rondinone, lead author of the team's study published in ChemistrySelect. "We were trying to study the first step of a proposed reaction when we realized that the catalyst was doing the entire reaction on its own."

The chemical reaction that takes place is very complicated and is said to essentially reverse the combustion process. The nanotech catalyst has multiple reaction sites and a solution of carbon dioxide dissolved in water was transformed into ethanol with a yield of 63%. The team notes that this sort of reaction typically yields a mix of several different products in small amounts.

"We're taking carbon dioxide, a waste product of combustion, and we're pushing that combustion reaction backwards with very high selectivity to a useful fuel," Rondinone said. "Ethanol was a surprise — it's extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst."

The catalyst that the team developed consists of copper nanoparticles embedded in carbon spikes using a nano-texturing approach. This process doesn't require any expensive or rare metals like platinum. Not only is the catalyst low cost, but the entire reaction is able to operate at room temperature in water. The team thinks that the entire process could be scaled up for industrial applications. Study of the catalyst's properties and behavior will continue says the researchers.