We've all heard that carbon dioxide (CO2) emissions need urgent solutions, but what if we could turn this greenhouse gas into useful chemicals or fuels? Electrochemical CO2 conversion—the process of transforming carbon dioxide into valuable products—is a promising path toward greener energy and reducing emissions. The catch? Existing methods either don't last long or consume too much energy, limiting their real-world use.
Low-temperature CO2 conversion, for instance, typically lasts less than 100 hours and reaches efficiencies below 35%. The process can be more practical at higher temperatures—between 600 and 1,000 degrees Celsius—but current catalysts often wear out quickly or require costly precious metals. The technology needs an efficient, stable, and cost-effective solution that can turn CO2 into useful products like carbon monoxide, a key ingredient in many industrial processes.
Now, a team led by Professor Xile Hu at EPFL has crafted a new type of catalyst that promises to make this high-temperature conversion more practical and cost-effective. The catalyst could accelerate the transition towards cleaner industries by converting CO2 into usable chemicals and fuels.
The researchers developed an innovative catalyst made from a cobalt-nickel (Co-Ni) alloy encapsulated within a ceramic material called Sm2O3-doped CeO2 (SDC). The encapsulation prevents the metal from agglomerating (clumping together), a common problem that reduces catalyst effectiveness. Impressively, their catalyst operates at 90% energy efficiency, 100% product selectivity, and sustains its performance over an unprecedented 2,000 hours, far surpassing existing technologies.
To create the catalyst, first-author and EPFL postdoc Wenchao Ma, used a sol-gel method, a process that mixes metal salts with organic molecules to form tiny metal clusters encased by ceramic shells. They tested different combinations of metals, discovering that a balanced mix of cobalt and nickel delivered the best performance. Unlike traditional catalysts, which quickly degrade under intense heat, the encapsulated alloy remained stable, maintaining its efficiency even after thousands of hours of continuous operation.
The results were remarkable. The new catalyst maintained an energy efficiency of 90% at 800 degrees Celsius while converting CO2 into carbon monoxide—a valuable chemical used in industrial processes—with 100% selectivity. In simpler terms, nearly all the electricity used in the reaction directly contributed to producing the desired chemical, without wasteful side reactions.
The breakthrough brings us closer to practical, cost-effective carbon recycling. Instead of releasing CO2 into the atmosphere, industries could reuse it, transforming waste gas into valuable products. This technology could help industries reduce their environmental footprint, saving both energy and money in the process.
The EPFL team's catalyst remained stable at industrially relevant conditions for more than 2,000 hours, a milestone that dramatically reduces operating costs. Compared to existing technologies, their approach could cut overall costs by 60% to 80%, according to the researchers' preliminary estimate.
The catalyst is a significant step towards cleaner industries. By turning CO2 into valuable products efficiently, we can envision a future where industries recycle carbon emissions as routinely as we recycle paper and plastic today. The EPFL team has filed an international patent application for the catalyst.
Other contributors
- Institute of Chemical Research of Catalonia (ICIQ-CERCA)
- National Taiwan University
- Technical University of Denmark
Reference
Wenchao Ma, Jordi Morales-Vidal, Jiaming Tian, Meng-Ting Liu, Seongmin Jin, Wenhao Ren, Julian Taubmann, Christodoulos Chatzichristodoulou, Jeremy Luterbacher, Hao Ming Chen, Núria López, Xile Hu. Encapsulated Co-Ni alloy boosts high-temperature CO2 electroreduction. Nature 14 May 2025. DOI: 10.1038/s41586-025-08978-0
