Neutron diffraction paves the way to net zero through carbon capture
28 Apr 2026 - Peter Hurrell
Carbon capture technology is at the forefront of the UK Government’s strategy to reach net zero. Now, researchers have used neutron diffraction at ISIS to reveal details of the interactions of two amino acid-based carbon capture solvents. The information gained will help researchers optimise carbon capture solvents for large-scale deployment.
To reach the UK’s net zero target by 2025 a mixed approach to decarbonising our infrastructure will be required. Shifting to renewable energy generation and reducing carbon emissions from transport, industry and elsewhere will be vitally important, but in some cases that may not possible. Carbon-based energy generation will supplement renewable energy generation for some time to come, and some industries such as cement and steel production emit CO2 from their manufacturing processes. To mitigate CO2 emissions from these sources will require carbon capture, utilisation and storage (CCUS) technology.
CCUS works by pumping emissions containing CO2 through a solvent that can bind to and remove the CO2 from the waste gases. That solvent is then heated to release the pure CO2, which can either be used as a feedstock in other chemical manufacturing, or sent into geological storage.
In this study, researchers from the University of Leeds, C-Capture Ltd, and ISIS, used neutron diffraction to examine key interactions in the process by which two solvents capture carbon. They chose to study two aqueous amino acid salt solutions, in which the amino acid glycine is combined with either sodium or potassium. These capture CO2 by forming carbamates and bicarbonate. The team were able to examine the two aqueous amino acid salt solutions both before and after loading with CO2.
Three key features
Neutron diffraction on the NIMROD and SANDALS instruments at ISIS let the team investigate the atomic-scale structure of the solvents and their interactions with water and CO2. Neutrons provide access to structural information unavailable via other techniques. They are non-destructive and can utilise hydrogen/deuterium substitution to provide additional structural information. By refining data from computer simulations of the interactions until it aligns with the neutron diffraction data in a process called empirical potential structure refinement (EPSR), the researchers could determine the structure of the solvents in solution.
The study focussed on three key structural features involved in the CO2 loading process. They found that the shell of water surrounding the solvent ions played a major role in CO2 loading, suggesting that modifying the solvent to destabilise that shell could accelerate their CO2 loading. They also showed why potassium-based salts are quicker CO2 absorbers, due to a less stable association around the CO2 binding site that creates a lower energetic barrier for CO2 molecules. Finally, they showed that interactions with both water and with the potassium or sodium ions were equally important in the offloading of CO2 from the amino acid.
This collaborative project is a great demonstration of the importance of neutrons in supporting our journey towards a more sustainable future.
Harrison Laurent, University of Leeds
Neutron diffraction is critically important for this research as it provides a high-resolution toolkit for studying CO2 loaded solutions and has the potential to advance the understanding and application of a range of carbon capture solvent systems.
Lorna Dougan, University of Leeds
The findings are important because they provide new information which can be used to optimise carbon capture solvents that take advantage of these interactions to make the process more efficient. The study also shows how neutron diffraction can be an important tool in the design of next generation CCUS agents.
Find out more in the Nature Research Communities article written by the researchers: https://communities.springernature.com/posts/neutron-diffraction-provides-molecular-insight-into-carbon-capture-solutions
Related publication: Visualising reaction complexes in amine-based unloaded and CO2-loaded carbon capture solutions | Nature Communications
The research is supported through the European Research Council Consolidator Fellowship/UKRI Frontier Research Fellowship for the MESONET project, UKRI EP/X023524/1 to L. Dougan.
