Abstract
Efficient CO2 electroreduction to multi-carbon (C2+) oxygenates in acidic electrolytes remains a great challenge, especially under high current density conditions. In this study, we prepare an ionic liquid (IL)-modified Cu electrode (IL@Cu), which achieve a Faradaic efficiency (FE) of 82.7% toward C2+ products at a current density of 2.0 A cm−2 in 0.5 M K2SO4 (pH = 1, adjusted with H2SO4), with a single-pass carbon efficiency reaching 78.5%. Under the same conditions, the partial current density for C2+ oxygenates and ethanol exceed 1.2 A cm−2 and 1.0 A cm−2, respectively, over IL@Cu. Mechanism study has shown that K+ cations are repelled by the IL cations during the reaction, allowing water molecules to access the electrode surface. The displacement of K+ enhances C–C coupling, while the proximity of water to the electrode surface facilitates the incorporation of oxygen-containing intermediates into the hydrogen bond network, thereby promoting the formation of C2+ oxygenates.
References
He, M., Sun, Y. & Han, B. Green carbon science: efficient carbon resource processing, utilization, and recycling towards carbon neutrality. Angew. Chem. Int. Ed. 61, e202112835 (2022).
Yang, Y. et al. Operando studies reveal active Cu nanograins for CO2 electroreduction. Nature 614, 262–269 (2023).
Jia, S. et al. Electrochemical conversion of CO2 via C−X bond formation: recent progress and perspective. Chem. Synth. 4, 60 (2024).
Zhang, Y. et al. Low-coordinated copper facilitates the *CH2CO affinity at enhanced rectifying interface of Cu/Cu2O for efficient CO2-to-multicarbon alcohols conversion. Nat. Commun. 15, 5172 (2024).
Gao, X. et al. Intermediate-regulated dynamic restructuring at Ag-Cu biphasic interface enables selective CO2 electroreduction to C2+ fuels. Nat. Commun. 15, 10331 (2024).
Yin, Y. et al. Modulating CO2 electroreduction pathways through controlled ionomer arrangement on catalyst surfaces via solvent dispersion. Innovation 6, 100882 (2025).
Yang, P. & Gao, M. Enrichment of reactants and intermediates for electrocatalytic CO2 reduction. Chem. Soc. Rev. 52, 4343–4380 (2023).
Li, Z. et al. Mesostructure-specific configuration of *CO adsorption for selective CO2 electroreduction to C2+ products. Angew. Chem. Int. Ed. 64, e202413832 (2025).
Bi, J. et al. Construction of 3D copper-chitosan-gas diffusion layer electrode for highly efficient CO2 electrolysis to C2+ alcohols. Nat. Commun. 14, 2823 (2023).
Zhao, Y. et al. Conversion of CO2 to multicarbon products in strong acid by controlling the catalyst microenvironment. Nat. Synth. 2, 403–412 (2023).
Cao, Y. et al. Surface hydroxide promotes CO2 electrolysis to ethylene in acidic conditions. Nat. Commun. 14, 2387 (2023).
Cao, X., Cha, S. & Gong, M. Interfacial electrical double layer in electrocatalytic reactions: fundamentals, characterizations and applications. Acta Phys. -Chim. Sin 41, 2410018 (2025).
Shayesteh Zeraati, A. et al. Carbon- and energy-efficient ethanol electrosynthesis via interfacial cation enrichment. Nat. Synth. 4, 75–83 (2025).
Liu, Z. et al. Switching CO2 electroreduction toward ethanol by delocalization state-tuned bond cleavage. J. Am. Chem. Soc. 146, 14260–14266 (2024).
Li, J. et al. Twin heterostructure engineering and facet effect boosts efficient reduction CO2-to-ethanol at low potential on Cu2O@Cu2S catalysts. ACS Catal. 14, 266–3277 (2024).
Fu, W. et al. Preserving molecular tuning for enhanced electrocatalytic CO2-to-ethanol conversion. Angew. Chem. Int. Ed. 63, e202407992 (2024).
Zhang, H. et al. Dynamic ionization equilibrium-induced “oxygen exchange” in CO electroreduction. ACS Catal. 14, 10737–10745 (2024).
Zhou, J. et al. Regulating interfacial hydrogen-bonding networks by implanting Cu sites with perfluorooctane to accelerate CO2 electroreduction to ethanol. Angew. Chem. Int. Ed. 64, e202418459 (2024).
Li, J. et al. MOFs-based single/dual-atom catalysts: atomically active sites engineering for efficient CO2 reduction. Chem. Synth. 5, 69 (2025).
Monteiro, M. C. O. et al. Absence of CO2 electroreduction on copper, gold and silver electrodes without metal cations in solution. Nat. Catal. 4, 654–662 (2021).
Zhang, Z. et al. Molecular understanding of the critical role of alkali metal cations in initiating CO2 electroreduction on Cu(100) surface. Nat. Commun. 15, 612 (2024).
Tan, Z. et al. Alkaline ionic liquid microphase promotes deep reduction of CO2 on copper. J. Am. Chem. Soc. 145, 21983–21990 (2024).
Ahmed, Y. et al. Interface modification by ionic liquid for efficient and stable FAPbI3 perovskite solar cells. Acta Phys. Chim. Sin 40, 2303057 (2024).
Zhang, M. et al. Mechanism of efficient electroreduction of CO2 to CO at Ag electrode in imidazolium-based ionic liquids/acetonitrile solution. Appl. Catal. B 359, 124508 (2024).
Dongare, S. et al. A bifunctional ionic liquid for capture and electrochemical conversion of CO2 to CO over silver. ACS Catal 13, 7812–7821 (2023).
Coskun, O. K. et al. Tailoring electrochemical CO2 reduction on copper by reactive ionic liquid and native hydrogen bond donors. Angew. Chem. Int. Ed. 136, e202312163 (2024).
Sha, Y. et al. Anchoring ionic liquid in copper electrocatalyst for improving CO2 conversion to ethylene. Angew. Chem. Int. Ed. 61, e202200039 (2024).
Cai, H. et al. Ionic liquid-induced product switching in CO2 electroreduction on copper reaction interface. Adv. Funct. Mater. 34, 2404102 (2024).
Kang, X. et al. Synthesis of hierarchical porous metals using ionic-liquid-based media as solvent and template. Angew. Chem. Int. Ed. 56, 12683–12686 (2017).
Kang, X. et al. Formation of large nanodomains in liquid solutions near the phase boundary. Chem. Commun. 52, 14286–14289 (2016).
Xu, B. et al. Highly efficient electrocatalytic CO2 reduction to C2+ products on a poly(ionic liquid)-based Cu(0)-Cu(I) tandem catalyst. Angew. Chem. Int. Ed. 61, e20211065 (2022).
Qin, D. et al. Enhanced electrochemical nitrate-to-ammonia performance of cobalt oxide by protic ionic liquid modification. Angew. Chem. Int. Ed. 62, e202304935 (2023).
Kiefer, J., Fries, J. & Leipertz, A. Experimental vibrational study of imidazolium-based ionic liquids: raman and infrared spectra of 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide and 1-ethyl-3-methylimidazolium ethyl sulfate. Appl. Spectrosc. 61, 1306–1311 (2007).
Dhumal, N., Noack, K., Kiefer, J. & Kim, H. Molecular structure and interactions in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. J. Phys. Chem. A 118, 2547–2557 (2014).
Cao, Y. et al. A transparent, self-healing, highly stretchable ionic conductor. Adv. Mater. 29, 1–9 (2017).
Lian, Z., Dattila, F. & López, N. Stability and lifetime of diffusion-trapped oxygen in oxide-derived copper CO2 reduction electrocatalysts. Nat. Catal. 7, 401 (2024).
Zhang, P. et al. Tuning the surface field by embedding cations into metals to direct the reaction pathway of CO2 electroreduction. CCS Chem 6, 631–640 (2024).
Liu, S. et al. Temperature-dependent pathways in carbon dioxide electroreduction. Sci. Bull. 70, 889–896 (2025).
Gunathunge, C. M. et al. Surface-adsorbed CO as an infrared probe of electrocatalytic interfaces. ACS Catal 10, 11700–11711 (2020).
Wang, P. et al. Boosting electrocatalytic CO2–to–ethanol production via asymmetric C–C coupling. Nat. Commun. 13, 3754 (2022).
Wang, Y. et al. In situ Raman spectroscopy reveals the structure and dissociation of interfacial water. Nature 600, 81–85 (2021).
Wang, Y. et al. Characterizing surface-confined interfacial water at graphene surface by in situ Raman spectroscopy. Joule 7, 1–11 (2023).
Chen, S. et al. Unveiling the proton-feeding effect in sulfur-doped Fe−N−C single-atom catalyst for enhanced CO2 electroreduction. Angew. Chem. Int. Ed. 61, e202206233 (2022).
Li, J. et al. Ethylene-glycol ligand environment facilitates highly efficient hydrogen evolution of Pt/CoP through proton concentration and hydrogen spillover. Energy Environ. Sci. 12, 2298–2304 (2019).
Zhu, Z. et al. Covalent organic framework ionomer steering the CO2 electroreduction pathway on Cu at industrial-grade current density. J. Am. Chem. Soc. 146, 1572–1579 (2024).
Ovalle, V. J. et al. Correlating hydration free energy and specific adsorption of alkali metal cations during CO2 electroreduction on Au. Nat. Catal. 5, 624–632 (2022).
Wang, S. et al. Manipulating C-C coupling pathway in electrochemical CO2 reduction for selective ethylene and ethanol production over single-atom alloy catalyst. Nat. Commun. 15, 10247 (2024).
Zhao, Z. et al. Highly efficient electroreduction of CO2 to ethanol via asymmetric C-C coupling by a metal-organic framework with heterodimetal dual sites. J. Am. Chem. Soc. 145, 26783–26790 (2023).
Zhan, C. et al. Key intermediates and Cu active sites for CO2 electroreduction to ethylene and ethanol. Nat. Energy 9, 1485–1496 (2024).
Li, Z. et al. A Small-angle X-ray scattering station at Beijing synchrotron radiation facility. Instrum. Sci. Technol. 42, 128–141 (2014).
Ravel, B. & Newville, M. ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrotron Radiat. 12, 537–541 (2005).
Sun, Z. et al. Fundamentals and challenges of electrochemical CO2 reduction using two-dimensional materials. Chem 3, 560–587 (2017).
Li, S. et al. Ampere-level CO2 electroreduction with single-pass conversion exceeding 85% in acid over silver penetration electrodes. Nat. Commun. 15, 6101 (2024).
Li, Z. et al. Directing CO2 electroreduction pathways for selective C2 product formation using single-site doped copper catalysts. Nat. Chem. Eng. 1, 159–169 (2024).
Jiao, J. et al. Lattice strain engineering boosts CO2 electroreduction to C2+ products. Angew. Chem. Int. Ed. 63, e202409563 (2024).
Abraham, M. J. et al. GROMACS: High performance molecular simulations through multi-level parallelism from laptops to supercomputers. SoftwareX 1-2, 19–25 (2015).
Heinz, H., Vaia, R. A., Farmer, B. L. & Naik, R. R. Accurate simulation of surfaces and interfaces of face-centered cubic metals using 12−6 and 9−6 lennard-jones potentials. J. Phys. Chem. C 112, 17281–17290 (2008).
Berendsen, H. J. C., Grigera, J. R. & Straatsma, T. P. The missing term in effective pair potentials. J. Phys. Chem. 91, 6269–6271 (1987).
Jorgensen, W. L., Maxwell, D. S. & Tirado-Rives, J. Development and testing of the OPLS all-atom force field on conformational energetics and properties of organic liquids. J. Am. Chem. Soc. 118, 11225–11236 (1996).
Melander, M. M. Frozen or dynamic? — An atomistic simulation perspective on the timescales of electrochemical reactions. Electrochim. Acta. 446, 142095 (2023).
Kuhne, T. D. et al. CP2K: An electronic structure and molecular dynamics software package - Quickstep: Efficient and accurate electronic structure calculations. J. Chem. Phys. 152, 194103 (2020).
Martyna, G. J., Klein, M. L. & Tuckerman, M. Nosé–Hoover chains: the canonical ensemble via continuous dynamics. J. Chem. Phys. 97, 2635–2643 (1992).
Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 78, 1396–1396 (1997).
Grimme, S. et al. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys. 132, 154104 (2010).
Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).
Grimme, S., Ehrlich, S. & Goerigk, L. Effect of the damping function in dispersion corrected density functional theory. J. Comput. Chem. 32, 1456–1465 (2011).
Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994).
Acknowledgements
We thank the National Natural Science Foundation of China (22273108, 22033009, 22293015, and 22121002), the Youth Innovation Promotion Association CAS (Y2022017), the CAS Project for Young Scientists in Basic Research (YSBR-050), the ICCAS Carbon Neutral Chemistry Program (CCNC-202403) and the National Key Research and Development Program of China (2023YFA1507400) for their financial support of this research. In situ SAXS-XAS measurements were performed on the 1W2B beamline of BSRF.
Author information
Authors and Affiliations
Contributions
Y.Y. and Z.L.: syntheses and characterizations of catalysts. S.L., S.Z., H.W., and L.J.: CO2RR experiments. W.L. and H.Q.: MD and DFT simulations. R.F. and X.S.: collection and analysis of in situ SERS and in situ ATR-SEIRAS spectra data. X.X., Y.X., and Q.Z.: collection and analysis of in situ XAS/SAXS combined technology. Q.Q. and J.Z.: mechanism analysis. X.K. and B.H.: overall design and direction of the project. Y.Y., X.K., and B.H.: preparation of the manuscript with help from all authors.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Communications thanks Yi Xiao and the other anonymous reviewer(s) for their contribution to the peer review of this work. A peer review file is available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Source data
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
About this article
Cite this article
Yin, Y., Ling, Z., Liu, S. et al. Ampere-level CO2 electroreduction to multi-carbon oxygenates in acidic electrolyte through surface microenvironment reconstruction. Nat Commun (2026). https://doi.org/10.1038/s41467-026-68739-z
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41467-026-68739-z
