A new process to convert carbon dioxide into ethanol has the potential to prevent large amounts of the greenhouse gas from entering the environment.
Scientists from Johannes Gutenberg University of Mainz in Germany have used cobalt and copper in a conversion technique called electrocatalysis.
“We can remove the greenhouse gas CO₂ from the environment and reintroduce it into a sustainable carbon cycle,” Professor Carsten Streb said.
Professor Streb said assuming green electricity was used for this process, it would also be sustainable and food crops currently used to produce ethanol for fuels would be available for food again.
He said the conversion technique, which has so far been carried out on a laboratory scale, could be realized on a larger scale.
“The electrochemical conversion of CO₂ to multicarbon products, such as ethanol, would be an ideal way to obtain high energy density fuels and valuable chemical raw materials, while at the same time using CO₂ as a precursor and thus removing it from the atmosphere.”
Professor Streb said the research team designed a special electrode where the chemical reactions took place, coated with a black powder containing cobalt and copper in precisely dosed quantities.
“The initial challenge is to get carbon dioxide to react,” he said.
“The bonds between the atoms of the molecule are very strong, but cobalt can break them.”
Professor Streb said, initially, the process produced carbon monoxide, but a second step, involving copper, completed the conversion to ethanol.
“However, this only works if cobalt and copper are close to each other on the electrode.”
Professor Streb said the abundance of cobalt and copper present on earth was a key factor in the choice of these two metals.
“The entire process could also be set up with precious metals like platinum or palladium, but at high costs without commercial prospects.”
Read the full study: Selective Electroreduction of CO2 to Ethanol via Cobalt–Copper Tandem Catalysts.
