Scientists have discovered a way to turn greenhouse gas into useful alcohol using a cobalt- and copper-coated electrode.

As many global industrial processes continue to spill carbon dioxide into the atmosphere, the two key carbon-reduction approaches are an overhaul of conventional practices by adopting green technology that reduces emissions at the source and mechanically removing CO2 from the air.

Circular systems that help create a market for this recaptured CO2 are needed to make it attractive, using the resulting carbon-based products as profitable incentives for private industries to push the technology forward.

Ethanol is a useful alcohol that is most notably used as a fuel and feedstock for other chemical processes. It serves as a starting material for producing other chemicals, enabling the creation of compounds like ethylene, which can be used in a range of materials from plastic to Lycra, essentially acting as a renewable source for various chemical manufacturing processes.

In a discovery published in ACS Catalysis, researchers have found a way to turn CO2 into ethanol using cobalt and copper in an electrode covered with a powder made from a very finely tuned combination of the metals, using electron microscopy to ensure the combination forms under exacting parameters.

"We can remove the greenhouse gas CO2 from the environment and reintroduce it into a sustainable carbon cycle," said co-author Professor Carsten Streb, a chemist at Johannes Gutenberg University Mainz, Germany.

In a lab setting, the research team was able to convert 80% of airborne CO2 into ethanol – the best result achieved in research to date. The researchers tested their work in a CO2-saturated environment, whereas normal atmospheric concentrations are currently much lower, around 420 parts per million. The team is currently working on improving the yield of the process to 95%.

The electrode is coated with cobalt and copper in a precise configuration.

"The initial challenge is to get carbon dioxide to react," says Streb. This process first causes carbon monoxide to form, which the copper then converts into ethanol. "However, this only works if cobalt and copper are close to each other on the electrode."

Ethanol is the most produced organic compound in the world; its high-value products are used in everything from the manufacture of medical devices to metal and plastic fabrication.

"The composite catalyst consists of neighboring cobalt and copper atoms anchored to electrically conductive nitrogen-doped carbon," says the report.

Copper is much cheaper and more abundant than the more common catalyst materials of palladium and platinum.

"To achieve this, we require suitable catalysts capable of this conversion with high selectivity so that we obtain a high yield of the desired product, which – in our case – is ethanol," says Streb.

This breakthrough is one of several other encouraging studies of carbon reactions with various materials aiming to create useful chemicals, utilizing CO2 captured from the atmosphere and during industrial processes in a circular, carbon-neutral method.