Scientists at the US Department of Energy’s Oak Ridge National Laboratory (ORNL) have developed a nanotechnology-based catalyst to convert carbon dioxide into ethanol.

The catalyst, which has a nanoscale structure, consists of copper nanoparticles embedded in carbon spikes, according to ORNL.

Lead author of the team’s study published in ChemistrySelect Adam Rondinone said: “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.

“Ethanol was a surprise — it’s extremely difficult to go straight from carbon dioxide to ethanol with a single catalyst.”

Using the nanotechnology-based catalyst, the scientists turned the solution of carbon dioxide dissolved in water into ethanol with a yield of 63%.

According to the researchers’ initial analysis, the spiky textured surface of the catalysts offers ample reactive sites for carbon dioxide-to-ethanol conversion.

Rondinone said: “They are like 50-nanometer lightning rods that concentrate electrochemical reactivity at the tip of the spike.”

The technique depends on low-cost materials and has an ability to operate at room temperature in water.

Given these features, the researchers think that the approach could be scaled up for industrially relevant applications such as storing surplus electricity produced from variable power sources such as wind and solar.

 Rondinone added: “A process like this would allow you to consume extra electricity when it’s available to make and store as ethanol.

“This could help to balance a grid supplied by intermittent renewable sources.”

The researchers plan to refine the approach to increase the overall production rate and further study the catalyst’s properties and behavior.

Image: ORNL’s Yang Song (seated), Dale Hensley (standing left) and Adam Rondinone examine a carbon nanospike sample with a scanning electron microscope. Photo courtesy of Oak Ridge National Laboratory.