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Experimental evidence of distinct sites for CO2-to-CO and CO conversion on Cu in the electrochemical CO2 reduction reaction

Nature Catalysis volume 6, pages 885–894 (2023)Cite this article

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Abstract

The electrochemical CO2 reduction reaction on Cu is widely believed to occur via two consecutive and orthogonal reaction steps, that is, CO2-to-CO and CO-to-C2+, on the same sites. Here we provide compelling experimental evidence that challenges these long-held assumptions. We show that the presence of CO2 promotes the electrochemical CO reduction reaction, and there are at least two distinct types of Cu sites, with one (CuCO2) more active in the CO2-to-CO conversion and the other (CuCO) favouring the further reduction of CO to C2+ products. CO adsorbed on CuCO is at least six times more active towards the formation of C2+ products than that on CuCO2. Isotopic labelling experiments on Cu(111) and Cu(100) surfaces indicate that CuCO2 and CuCO probably correspond to Cu(111)-like and defect sites, respectively. These insights highlight the possibility of selectivity control in the CO2 reduction reaction.

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Fig. 1: Co-electrolysis of CO/CO2 and in situ spectroscopic characterization.
Fig. 2: Co-electrolysis of 13CO/12CO2 (4:1) on Den-Cu.
Fig. 3: Distribution of ethylene isotopologues in the co-electrolysis of 13CO/12CO2.
Fig. 4: Isotopologue distribution of C2 products in the co-electrolysis of 13CO/12CO2.
Fig. 5: The two-site model and its predictions.
Fig. 6: Distribution of ethylene isotopologues on single crystal Cu surface.

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Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request. Source data are provided with this paper.

References

  1. Centi, G., Quadrelli, E. A. & Perathoner, S. Catalysis for CO2 conversion: a key technology for rapid introduction of renewable energy in the value chain of chemical industries. Energy Environ. Sci. 6, 1711 (2013).

    Article  CAS  Google Scholar 

  2. Weber, R. S. Effective use of renewable electricity for making renewable fuels and chemicals. ACS Catal. 9, 946–950 (2019).

    Article  CAS  Google Scholar 

  3. Luna, P. D. et al. What would it take for renewably powered electrosynthesis to displace petrochemical processes? Science 364, 350 (2019).

    Google Scholar 

  4. Chu, S., Cui, Y. & Liu, N. The path towards sustainable energy. Nat. Mater. 16, 16–22 (2017).

    Article  Google Scholar 

  5. Hori, Y. et al. Production of methane and ethylene in electrochemical reduction of carbon dioxide at copper electrode in aqueous hydrogencarbonate solution. Chem. Lett. 15, 897–898 (1986).

    Article  Google Scholar 

  6. Kuhl, K. P., Cave, E. R., Abram, D. N. & Jaramillo, T. F. New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces. Energy Environ. Sci. 5, 7050–7059 (2012).

    Article  CAS  Google Scholar 

  7. Raciti, D. & Wang, C. Recent advances in CO2 reduction electrocatalysis on copper. ACS Energy Lett. 3, 1545–1556 (2018).

    Article  CAS  Google Scholar 

  8. Wang, L. et al. Electrochemical carbon monoxide reduction on polycrystalline copper: effects of potential, pressure, and pH on aelectivity toward multicarbon and oxygenated products. ACS Catal. 8, 7445–7454 (2018).

    Article  CAS  Google Scholar 

  9. Hori, Y., Murata, A., Takahashi, R. & Suzuki, S. Electroreduction of CO to CH4 and C2H4 at a copper electrode in aqueous-solutions at ambienttemperature and pressure. J. Am. Chem. Soc. 109, 5022–5023 (1987).

    Article  CAS  Google Scholar 

  10. Li, H., Jiang, K., Zou, S. Z. & Cai, W. B. Fundamental aspects in CO2 electroreduction reaction and solutions from in situ vibrational spectroscopies. Chin. J. Catal. 43, 2772–2791 (2022).

    Article  CAS  Google Scholar 

  11. Wuttig, A., Yoon, Y., Ryu, J. & Surendranath, Y. Bicarbonate is not a general acid in Au-catalyzed CO2 electroreduction. J. Am. Chem. Soc. 139, 17109–17113 (2017).

    Article  CAS  PubMed  Google Scholar 

  12. Xiao, H., Cheng, T., Goddard, W. A. 3rd & Sundararaman, R. Mechanistic explanation of the pH dependence and onset potentials for hydrocarbon products from electrochemical reduction of CO on Cu (111). J. Am. Chem. Soc. 138, 483–486 (2016).

    Article  CAS  PubMed  Google Scholar 

  13. Wu, G. L. et al. Selective electroreduction of CO2 to n-propanol in two-step tandem catalytic system. Adv. Energy Mater. 12, 2202054 (2022).

    Article  CAS  Google Scholar 

  14. Overa, S. et al. Tandem and hybrid processes for carbon dioxide utilization. Joule 5, 8–13 (2021).

    Article  Google Scholar 

  15. Huang, J. F., Mensi, M., Oveisi, E., Mantella, V. & Buonsanti, R. Structural sensitivities in bimetallic catalysts for electrochemical CO2 reduction revealed by Ag–Cu nanodimers. J. Am. Chem. Soc. 141, 2490–2499 (2019).

    Article  CAS  PubMed  Google Scholar 

  16. Ting, L. R. L. et al. Enhancing CO2 electroreduction to ethanol on copper–silver composites by opening an alternative catalytic pathway. ACS Catal. 10, 4059–4069 (2020).

    Article  CAS  Google Scholar 

  17. Lv, X. M. et al. Electron-deficient Cu sites on Cu3Ag1 catalyst promoting CO2 electroreduction to alcohols. Adv. Energy Mater. 10, 2001987 (2020).

    Article  CAS  Google Scholar 

  18. Jia, H. L. et al. Symmetry-broken Au–Cu heterostructures and their tandem catalysis process in electrochemical CO2 reduction. Adv. Funct. Mater. 31, 2101255 (2021).

    Article  CAS  Google Scholar 

  19. Wang, X. et al. Mechanistic reaction pathways of enhanced ethylene yields during electroreduction of CO2–CO co-feeds on Cu and Cu-tandem electrocatalysts. Nat. Nanotechnol. 14, 1063–1070 (2019).

    Article  CAS  PubMed  Google Scholar 

  20. Li, J. et al. Electrokinetic and in situ spectroscopic investigations of CO electrochemical reduction on copper. Nat. Commun. 12, 3264 (2021).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Chang, X. et al. C–C coupling is unlikely to be the rate-determining step in the formation of C2+ Products in the copper-catalyzed electrochemical reduction of CO. Angew. Chem. Int. Ed. 134, e202111167 (2022).

    Article  Google Scholar 

  22. Chang, X. X. et al. Determining intrinsic stark tuning rates of adsorbed CO on copper surfaces. Catal. Sci. Technol. 11, 6825 (2021).

    Article  CAS  Google Scholar 

  23. Chang, X. et al. Understanding the complementarities of surface-enhanced infrared and Raman spectroscopies in CO adsorption and electrochemical reduction. Nat. Commun. 13, 2656 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Gunathunge, C. M., Ovalle, V. J., Li, Y., Janik, M. J. & Waegele, M. M. Existence of an electrochemically inert CO population on Cu electrodes in alkaline pH. ACS Catal. 8, 7507–7516 (2018).

    Article  CAS  Google Scholar 

  25. Lu, X. F., Shinagawa, T. & Takanabe, K. Product distribution control guided by a microkinetic analysis for CO reduction at high-flux electrocatalysis using gas-diffusion Cu electrodes. ACS Catal. 13, 1791–1803 (2023).

    Article  CAS  Google Scholar 

  26. Hollins, P. & Pritchard, J. Interactions of CO molecules adsorbed on Cu (111). Surf. Sci. 89, 486–495 (1979).

    Article  CAS  Google Scholar 

  27. Lum, Y. & Ager, J. W. Evidence for product-specific active sites on oxide-derived Cu catalysts for electrochemical CO2 reduction. Nat. Catal. 2, 86–93 (2019).

    Article  CAS  Google Scholar 

  28. Hou, J. J., Chang, X. X., Li, J., Xu, B. J. & Lu, Q. Correlating CO coverage and CO electroreduction on Cu via high-pressure in situ spectroscopic and reactivity investigations. J. Am. Chem. Soc. 144, 22202–22211 (2022).

    Article  CAS  PubMed  Google Scholar 

  29. Xiong, H. C. et al. Correlating the experimentally determined CO adsorption enthalpy with the electrochemical CO reduction performance on Cu surfaces. Angew. Chem. Int. Ed. 62, e202218447 (2023).

  30. Hori, Y., Takahashi, I., Koga, O. & Hoshi, N. Electrochemical reduction of carbon dioxide at various series of copper single crystal electrodes. J. Mol. Catal. A 199, 39–47 (2003).

    Article  CAS  Google Scholar 

  31. Zhong, D. Z. et al. Coupling of Cu (100) and (110) facets promotes carbon dioxide conversion to hydrocarbonsand alcohols. Angew. Chem. Int. Ed. 60, 4879–4885 (2021).

    Article  CAS  Google Scholar 

  32. Hori, Y., Wakebe, H., Tsukamoto, T. & Koga, O. Adsorption of CO accompanied with simultaneous charge transfer on copper single crystal electrodes related with electrochemical reduction of CO2 to hydrocarbons. Surf. Sci. 335, 258–263 (1995).

    Article  CAS  Google Scholar 

  33. Bagger, A., Ju, W., Varela, A. S., Strasser, P. & Rossmeisl, J. Electrochemical CO2 reduction: a classification problem. ChemPhysChem 18, 3266–3273 (2017).

    Article  CAS  PubMed  Google Scholar 

  34. Li, J. H., Maresi, I., Lum, Y. W. & Ager, J. W. Effects of surface diffusion in electrocatalytic CO2 reduction on Cu revealed by kinetic Monte Carlo simulations. J. Chem. Phys. 155, 164701 (2021).

    Article  CAS  PubMed  Google Scholar 

  35. Schreier, M., Yoon, Y., Jackson, M. N. & Surendranath, Y. Competition between H and CO for active sites governs copper-mediated electrosynthesis of hydrocarbon fuels. Angew. Chem. Int. Ed. 57, 10221–10225 (2018).

    Article  CAS  Google Scholar 

  36. Lee, S. H. et al. Oxidation state and surface reconstruction of Cu under CO2 reduction conditions from in situ X-ray characterization. J. Am. Chem. Soc. 143, 588–592 (2021).

    Article  CAS  PubMed  Google Scholar 

  37. Simon, G. H., Kley, C. S. & Cuenya, B. R. Potential-dependent morphology of copper catalysts during CO2 electroreduction revealed by in situ atomic force microscopy. Angew. Chem. Int. Ed. 60, 2561–2568 (2021).

    Article  CAS  Google Scholar 

  38. Huang, Y., Handoko, A. D., Hirunsit, P. & Yeo, B. S. Electrochemical reduction of CO2 using copper single-crystal surfaces: effects of CO* coverage on the selective formation of ethylene. ACS Catal. 7, 1749–1756 (2017).

    Article  CAS  Google Scholar 

  39. Nitopi, S. et al. Progress and perspectives of electrochemical CO2 reduction on copper in aqueous electrolyte. Chem. Rev. 119, 7610–7672 (2019).

    Article  CAS  PubMed  Google Scholar 

  40. Liu, X. et al. Understanding trends in electrochemical carbon dioxide reduction rates. Nat. Commun. 8, 15438 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  41. Tang, W. et al. The importance of surface morphology in controlling the selectivity of polycrystalline copper for CO2 electroreduction. Phys. Chem. Chem. Phys. 14, 76–81 (2021).

    Article  Google Scholar 

  42. Jiang, K. et al. Metal ion cycling of Cu foil for selective C–C coupling in electrochemical CO2 reduction. Nat. Catal. 1, 111–119 (2018).

    Article  CAS  Google Scholar 

  43. Dunwell, M. et al. The central role of bicarbonate in the electrochemical reduction of carbon dioxide on Gold. J. Am. Chem. Soc. 139, 3774–3783 (2017).

    Article  CAS  PubMed  Google Scholar 

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Acknowledgements

This work is supported by the Beijing National Laboratory for Molecular Sciences. W.G. acknowledges the support of the Project funded by China Postdoctoral Science Foundation (2022M710183). The authors thank Y. Zhang and C. Fan for the assistance with numerical analysis.

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Author notes

  1. These authors contributed equally: Wenqiang Gao, Yifei Xu.

Authors and Affiliations

  1. College of Chemistry and Molecular Engineering, Peking University, Beijing, China

    Wenqiang Gao, Yifei Xu, Linke Fu, Xiaoxia Chang & Bingjun Xu

  2. Beijing National Laboratory for Molecular Sciences, Beijing, China

    Wenqiang Gao, Yifei Xu, Linke Fu, Xiaoxia Chang & Bingjun Xu

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Contributions

W.G., Y.X. and B.X. conceived the idea and designed experiments in this study. W.G. synthesized and characterized the catalysts, and conducted the electrochemical tests. Y.X. performed SEIRAS experiments. L.F. performed part of the electrochemical tests. W.G., Y.X., X.C. and B.X. analysed data, and co-wrote the manuscript, with input from all other co-authors.

Corresponding author

Correspondence to Bingjun Xu.

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Nature Catalysis thanks Joel Ager III, Wen-Bin Cai and the other, anonymous, reviewer for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–31, Notes 1–6, Tables 1–4 and References 1–8.

Supplementary Data 1

Source data for supplementary figures.

Source data

Source Data Fig. 1

Co-electrolysis of CO/CO2 and in situ spectroscopic characterization.

Source Data Fig. 2

Co-electrolysis of 13CO/12CO2 (4:1) on Den-Cu.

Source Data Fig. 3

Distribution of ethylene isotopologues in the co-electrolysis of 13CO/12CO2.

Source Data Fig. 4

Isotopologue distribution of C2 products in the co-electrolysis of 13CO/12CO2.

Source Data Fig. 5

The two-site model and its predictions.

Source Data Fig. 6

Distribution of ethylene isotopologues on single crystal Cu surface.

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Gao, W., Xu, Y., Fu, L. et al. Experimental evidence of distinct sites for CO2-to-CO and CO conversion on Cu in the electrochemical CO2 reduction reaction. Nat Catal 6, 885–894 (2023). https://doi.org/10.1038/s41929-023-01002-6

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