Many people know ethylene from their kitchen. This colorless, sweet-smelling gas is a natural plant hormone, responsible for ripening apples, tomatoes and bananas. But ethylene is also an important industrial chemical with global production exceeding 317 million tons annually. It is mainly used as a platform chemical: a precursor or reagent to create a multitude of chemical products, from plastics to pharmaceuticals.

More than 95% of ethylene is currently produced through fossil-based steam cracking processes that generate approximately 260 million tons of CO₂ emissions each year. An EU project with Empa involvement aims to transform this carbon-intensive sector. The project, called REACT (short for Renewable Electrochemical Advanced Conversion of CO₂ to Target products), aims to provide a renewable alternative that converts industrial emissions into valuable resources.

The project focuses on recycling CO₂ from hard-to-abate industries such as steel, cement, and chemical manufacturing. Through a novel impurity-tolerant tandem electrochemical process, REACT can directly convert low-purity industrial CO₂ streams into valuable chemical products while significantly reducing the need for costly pre-treatment. Powered by renewable energy, the project takes previously unavoidable CO₂ emissions and turns them into a valuable feedstock for next-generation chemicals and materials.

Closer to implementation
"We have been working on CO₂ conversion through electrolysis at lab scale for many years", says Corsin Battaglia, head of Empa's Materials for Energy Conversion laboratory. "The goal of the REACT project is to create a working prototype electrolyser for the CO₂ to ethylene conversion, bringing it to a much higher technology readiness level", elaborates the researcher. Battaglia's team will study how the impurities in the industrial waste CO₂ influence the activity and the longevity of the catalyst used in the electrolyser. The Empa team can rely on the parallel CO₂ electrolysis reactor, which they have previously developed. The automated system in their lab allows for up to ten simultaneous experiments.

REACT advances circular carbon value chains, strengthens European industrial autonomy, and contributes to the transition towards climate-neutral chemical production. The project also integrates innovative materials, advanced monitoring systems, and digital twin technologies to enhance efficiency, durability, scalability, and economic feasibility. "What we learn and develop during REACT will also help advance other CO₂ conversion technologies, for example into synthetic fuels", summarizes Battaglia. Valorizing CO₂ is a core concept in Empa's research initiative, Mining the Atmosphere, which looks for ways to remove the greenhouse gas from the atmosphere and either store it long-term or convert it into useful chemical products, thus closing the cycle.

About REACT
REACT is a Horizon Europe project developing an innovative tandem electrochemical process to directly convert industrial CO₂ emissions into valuable olefin-rich chemical mixtures for the sustainable production of polymers, chemicals, and fuels. REACT (Renewable Electrochemical Advanced Conversion of CO₂ to Target products) is running for 48 months from May 2026 to April 2030 and covers the entire value chain, from scientific institutions to raw material suppliers and manufacturers of polymers for the packaging sector. The consortium is coordinated by SINTEF (Norway) and includes 13 partners from 10 countries: VITO (Belgium), Johnson Matthey PLC (UK), eChemicles (Hungary), Procter & Gamble Services Company NV (Belgium), IDENER (Spain), Norner Research AS (Norway), Empa (Switzerland), K1-MET GmbH (Austria), FARPLAS (Turkey), Johnson Matthey Davy Technologies Ltd (UK), Holoss (Portugal), and ETA-Florence Renewable Energies (Italy).