Turning carbon dioxide (CO₂) into useful fuels and chemicals is a major goal in clean energy research.
Copper is one of the best materials for this job—it can help convert CO₂ into valuable products using electricity.
But there’s a big problem: the process isn’t very efficient or stable, and scientists haven’t fully understood how it works at the atomic level. Until now.
A team of scientists from SLAC National Accelerator Laboratory and Lawrence Berkeley National Laboratory has developed a new way to watch copper atoms in action during these chemical reactions.
The challenge was that only a few copper atoms on the surface are actually involved in the reaction, while the rest of the copper just sits there. It’s like trying to watch a few dancers in a crowd of thousands.
To overcome this, the team used a special technique at SLAC’s Stanford Synchrotron Radiation Lightsource (SSRL).
Instead of running the reactor continuously, they turned it on and off several times per second—like a strobe light flashing rapidly.
At the same time, they hit the copper surface with powerful X-rays and recorded what was happening during the brief moments the reaction was active.
This method, called modulation excitation X-ray absorption spectroscopy (ME-XAS), let the researchers zoom in on tiny changes happening in just thousandths of a second.
For the first time, they could track what happens to individual copper atoms as they interact with electric pulses and begin turning CO₂ into other substances.
The scientists discovered key early steps in the reaction. First, hydroxide ions from the solution stick to the active copper atoms.
Then a form of copper called cuprous oxide begins to form. These are just the beginning steps, but understanding them is essential.
If the process continues without control, it creates a messy layer of copper compounds that interfere with the reaction and reduce the catalyst’s efficiency.
This new method doesn’t just apply to copper. The researchers believe it could help improve many types of electrochemical technologies, like fuel cells, batteries, and water-splitting systems. It’s especially valuable for studying devices powered by renewable energy sources that don’t produce steady energy, like solar or wind.
The experiment is part of the Liquid Sunlight Alliance (LiSA), a major U.S. project aiming to convert sunlight and CO₂ into clean fuel.
With this breakthrough, scientists now have a clearer view into how these reactions work at the smallest scales—an essential step toward building cleaner, more reliable energy systems for the future.
