Abstract
In power generation and industries where CO2 emissions are unavoidable, carbon capture, utilisation, and storage is an important tool to offset climate change. Many carbon capture agents are blends of aqueous amines, which absorb CO2 and are then thermally regenerated. The physical interactions between solutes play a crucial role in their reactivity and energy requirements for regeneration. Atomically resolved, experimentally derived information about the structure of these solutions, however, has yet to be reported. In this work, we report the structure of two model carbon capture solvents, aqueous sodium and potassium glycinate, in the unloaded and CO2-loaded state by performing structural refinement on H/D isotopically varied neutron diffraction data. This allows us to quantify the structure, frequency, and EPSR-derived pair interaction energetic stability of intermolecular interactions present. Such methodology can be readily applied to other carbon capture solutions, providing unparalleled insight and facilitating their large-scale modelling and rational design.
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Data availability
All data generated in this study have been deposited in a publicly available database under accession code https://doi.org/10.5518/1691. All data are available from the corresponding author upon request. All raw neutron diffraction data generated in this study have been deposited in a publicly available database under accession codes https://doi.org/10.5286/ISIS.E.RB2410275 and https://doi.org/10.5286/ISIS.E.RB2220355. Source data are present. Source data are provided with this paper.
Code availability
Python scripts for additional analysis routines have been deposited in a publicly available database under accession code https://doi.org/10.5518/1691.
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Acknowledgements
The project was supported by a grant from the Engineering and Physical Sciences Research Council (EPSRC) (EP/ P02288X/1) and a European Research Council Consolidator Fellowship/UKRI Frontier Research Fellowship for the MESONET project, UKRI EP/X023524/1 to L. Dougan. We are grateful to the University of Leeds and its alumni for a PhD scholarship to support Daniel Sault. We acknowledge the beamtimes at the ISIS neutron and muon facility (RB2410275 and RB2220355). We acknowledge C-Capture Ltd for use of their VLE apparatus.
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H.L. lead writing of the manuscript, gathered neutron diffraction data on unloaded and CO2-loaded samples, performed associated data correction, EPSR analysis, and wrote and performed additional analysis using bespoke analysis routines. D.S. aided in gathering neutron diffraction data on CO2-loaded samples, prepared all CO2-loaded samples, and gathered all NMR and VLE data. T.F.H. was the instrument scientist for the acquisition of unloaded neutron diffraction data on the NIMROD instrument. T.L.H. was the instrument scientist for the acquisition of CO2-loaded neutron diffraction data on the SANDALS instrument. Both T.F.H. and T.L.H. aided in data correction and EPSR analysis. J.W. supervised VLE data acquisition. C.R. helped with the CO2 loading experimental design and the discussion surrounding reaction mechanisms. L.D. is the corresponding author, co-wrote neutron diffraction access proposals, and aided in discussions around neutron diffraction experimental data and analysis. All authors contributed to writing, correcting, and discussing the manuscript.
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Laurent, H., Sault, D., Headen, T.F. et al. Visualising reaction complexes in amine-based unloaded and CO2-loaded carbon capture solutions. Nat Commun (2026). https://doi.org/10.1038/s41467-026-70391-6
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DOI: https://doi.org/10.1038/s41467-026-70391-6
