Every year, power plants and factories release billions of tons of carbon dioxide (CO₂) into the atmosphere. Methods exist to capture that CO₂ using chemical solutions and, separately, to convert pure CO₂ into useful fuels and chemicals. But doing both steps at once, in a cost-efficient and scalable way, has been difficult.
Now, researchers at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) and the U.S. Department of Energy's Argonne National Laboratory have developed a system that can simultaneously capture and convert CO₂. The approach, they reported in Nature Energy , offers a more efficient and potentially lower-cost approach than carrying out each step separately.
By swapping the water usually used in carbon capture and conversion systems for a different solvent, the team was able to capture CO₂ more efficiently and convert it into carbon monoxide, an industrially relevant building block for the chemical industry used to make a wide range of fuels and chemicals today. They also turned to zinc, rather than the usual silver, to catalyze the conversion reaction, bringing costs for the process down further.
"The concept of being able to integrate capture and conversion into a single step is a relatively new one, and we've made significant headway in not only showing that this is possible but that it can be done under conditions that are relevant for industrial deployment," said Chibueze Amanchukwu , Neubauer Family Assistant Professor of Molecular Engineering at UChicago PME and senior author of the new study.
One process instead of two
In conventional carbon capture, amines — nitrogen-based compounds that bind readily to CO₂ — are dissolved in water. Releasing the captured CO₂ for later use requires heating the solution to temperatures as high as 150°C and compressing the CO₂. Meanwhile, if that captured CO2 was converted in water, water carries out unwanted side reactions, ultimately leading to hydrogen gas.
Amanchukwu, whose lab focuses on electrochemistry in non-aqueous solvents, was brought together with scientists at Argonne National Laboratory through the University of Chicago Joint Task Force Initiative, a program designed to foster collaboration between the two institutions. About four years ago, the group formed a team and asked themselves what big problem was worth tackling together. They landed on reactive capture — the idea that CO₂ could be converted directly into a useful product while still bound to the amine.
"The challenge with current capture methods comes when you need to recover that CO₂. You need to boil the solution, which requires significant energy," said first author of the study Reginaldo Gomes, who completed his PhD at UChicago PME and is now a postdoctoral researcher at Argonne. "We asked whether, instead of going though those costly steps, we could use electricity to convert the captured CO₂ directly into something valuable."
Changing the solvent changes the chemistry
Many of the challenges around combining current capture and conversion methods revolve around water's unwanted chemical reactions. So the team began by replacing water with DMSO — a widely used industrial solvent.
In water, two amines must come together to bind each captured CO₂ molecule. Amanchukwu, Gomes, and their colleagues showed that in DMSO, the same amines form a different arrangement and can capture one CO₂ for every amine, doubling the system's capture capacity. At the same time, no CO₂ is lost to the competing chemical pathways that occur in water. Overall, the team observed nearly three times higher CO₂ uptake per amine molecule in DMSO compared to water.
With fewer hydrogen-forming side reactions, the group realized they could also make another change to the system. Silver catalysts, used in water-based capture approaches because they are resistant to making hydrogen, could be swapped for zinc — an earth-abundant metal far less expensive than the silver.
"We didn't anticipate how removing water would open up all these other new ways to make capture and conversion more efficient," said Amanchukwu. "It worked better than we had even hoped for."
Under lab conditions with pure CO₂, the zinc catalyst achieved 78% efficiency in converting captured CO₂ to carbon monoxide, a key industrial feedstock. Computational work by collaborator Cong Liu at Argonne revealed exactly why the zinc outperformed the silver in the DMSO system, requiring less energy.
Performing under real-world conditions
A critical test for any carbon capture technology is whether it works under actual industrial exhaust conditions rather than only with pure CO₂ in the lab. The team tested their system using simulated flue gas mixtures containing oxygen, which typically interferes with chemical reactions and can lower the efficiency of carbon capture and conversion.
The new approach still achieved up to 43% efficiency in converting CO₂ to carbon monoxide over multiple capture-and-conversion cycles. That figure matches what state-of-the-art water-based systems achieve using silver under pure CO₂, a far less challenging condition.
Collaborators at Argonne, led by Dr. Chukwunwike Iloeje, carried out a techno-economic analysis to estimate the cost of using DMSO instead of water. They found that the improved performance of the system, particularly higher CO₂ conversion, can substantially offset the higher solvent cost. Replacing silver with zinc in the DMSO system could further reduce costs by using a more active and abundant catalyst.
The researchers are candid that significant work remains before the system can be scaled up. It must be able to run for thousands of hours rather than days, and reaction rates must increase roughly tenfold to reach commercial viability. New reactor designs better suited to industrial scale will also be required. Still, a patent disclosure has been filed, and the team has already been contacted by industry.
"We established the scientific foundation for this system," said Gomes. "We're not just working with a pure, controlled CO₂ stream in the lab — we developed something that can start to handle the complexity of real-world challenges."
Citation: "Reactive CO₂ Capture via Controlled Amine Speciation in Nonaqueous Electrolytes," Gomes et al, Nature Energy, April 17, 2026. DOI: 10.1038/s41560-026-02035-4
Funding: This work was primarily funded by the University of Chicago Joint Task Force Initiative and the U.S. Department of Energy (DE-SC0024103, DE-AC02-06CH11357). Additional support was provided by the CIFAR Azrieli Global Scholars Program and the Research Corporation for Science Advancement Negative Emissions Science program.
