Researchers Develop Method to Convert CO₂ into Sustainable Ethanol

Researchers at Johannes Gutenberg University Mainz (JGU) have introduced a new method for converting carbon dioxide (CO₂) into ethanol, a sustainable raw material for chemical applications. This development could significantly contribute to reducing carbon emissions and mitigating climate change.

"We can remove the greenhouse gas CO₂ from the environment and reintroduce it into a sustainable carbon cycle," explained Professor Carsten Streb from the JGU Department of Chemistry. His research group demonstrated that CO₂ can be converted into ethanol using electrocatalysis. If powered by green electricity, this process becomes fully sustainable, and food crops currently used for ethanol production could be redirected towards nutritional purposes.

The research, published in ACS Catalysis, shows promise for scaling up from laboratory to industrial levels. The process offers an efficient method to turn CO₂ into valuable multicarbon products like ethanol, which serves as a high-energy density fuel and a critical chemical feedstock.

The conversion process involves a specialized electrode coated with cobalt and copper in specific quantities and configurations. Initially, cobalt breaks the strong bonds in the CO₂ molecule to form carbon monoxide. Then, copper catalyzes the reaction to convert the carbon monoxide into ethanol. The effectiveness of the process hinges on the proximity of the cobalt and copper on the electrode.

Currently, the process achieves an 80% selectivity rate, meaning 80% of the starting CO₂ is converted into ethanol—the highest success rate in research to date. The team aims to further improve this selectivity to 90-95% and, ideally, to reach 100%, leaving no by-products. Electron microscopy is crucial for observing the arrangement of atoms and optimizing the catalyst's performance.

The team is collaborating with researchers at Ulm University to develop a stable and long-lasting catalyst. The use of abundant metals like cobalt and copper makes this approach both practical and economically feasible, avoiding reliance on expensive precious metals like platinum or palladium.

Sustainably producing ethanol from CO₂ has multiple benefits. It would conserve food resources currently used for ethanol production, provide a new source of energy, and use readily available raw materials for catalysts. This innovative approach offers a way to produce ethanol that could be stored and used for decentralized power generation, contributing to a more sustainable energy system.