Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Electrochemical CO2-to-ethylene conversion on polyamine-incorporated Cu electrodes


Electrochemical conversion of CO2 into value-added chemicals holds promise to enable the transition to carbon neutrality. Enhancing selectivity for a specific hydrocarbon product is challenging, however, due to numerous possible reaction pathways of CO2 electroreduction. Here we present a Cu–polyamine hybrid catalyst, developed through co-electroplating, that significantly increases the selectivity for ethylene production. The Faradaic efficiency for ethylene production is 87% ± 3% at −0.47 V versus reversible hydrogen electrode, with full-cell energetic efficiency reaching 50% ± 2%. Raman measurements indicate that the polyamine entrained on the Cu electrode results in higher surface pH, higher CO content and higher stabilization of intermediates compared with entrainment of additives containing little or no amine functionality. More broadly, this work shows that polymer incorporation can alter surface reactivity and lead to enhanced product selectivity at high current densities.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Preparation of the Cu–polymer catalyst.
Fig. 2: Electrochemical CO2 conversion on the Cu–Pi electrodes.
Fig. 3: In situ electrochemical Raman spectroscopy measurements during the CO2RR.
Fig. 4: Calculated surface pH on different electrodes.
Fig. 5: Electrochemical characterization of the Cu–P1 catalyst in different concentrations of KOH electrolyte.

Data availability

The authors declare that the data supporting the findings of this study are available within the paper and its Supplementary Information files.


  1. 1.

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

    CAS  PubMed  Article  Google Scholar 

  2. 2.

    Verma, S., Lu, S. & Kenis, P. J. A. Co-electrolysis of CO2 and glycerol as a pathway to carbon chemicals with improved technoeconomics due to low electricity consumption. Nat. Energy 4, 466–474 (2019).

    CAS  Article  Google Scholar 

  3. 3.

    Montoya, J. H. et al. Materials for solar fuels and chemicals. Nat. Mater. 16, 70–81 (2016).

    PubMed  Article  CAS  Google Scholar 

  4. 4.

    Hepburn, C. et al. The technological and economic prospects for CO2 utilization and removal. Nature 575, 87–97 (2019).

    CAS  PubMed  Article  Google Scholar 

  5. 5.

    Hori, Y., Kikuchi, K., Murata, A. & Suzuki, S. 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. 6.

    Hori, Y., Wakebe, H., Tsukamoto, T. & Koga, O. Electrocatalytic process of CO selectivity in electrochemical reduction of CO2 at metal electrodes in aqueous media. Electrochim. Acta 39, 1833–1839 (1994).

    CAS  Article  Google Scholar 

  7. 7.

    Luc, W. et al. SO2-induced selectivity change in CO2 electroreduction. J. Am. Chem. Soc. 141, 9902–9909 (2019).

    CAS  PubMed  Article  Google Scholar 

  8. 8.

    Zhang, H. et al. Computational and experimental demonstrations of one-pot tandem catalysis for electrochemical carbon dioxide reduction to methane. Nat. Commun. 10, 3340 (2019).

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  9. 9.

    Yin, Z. et al. Cu3N nanocubes for selective electrochemical reduction of CO2 to ethylene. Nano Lett. 19, 8658–8663 (2019).

    CAS  PubMed  Article  Google Scholar 

  10. 10.

    Wang, Y. et al. Copper nanocubes for CO2 reduction in gas diffusion electrodes. Nano Lett. 19, 8461–8468 (2019).

    CAS  PubMed  Article  Google Scholar 

  11. 11.

    Hoang, T. T. H. et al. Nanoporous copper–silver alloys by additive-controlled electrodeposition for the selective electroreduction of CO2 to ethylene and ethanol. J. Am. Chem. Soc. 140, 5791–5797 (2018).

    CAS  PubMed  Article  Google Scholar 

  12. 12.

    Ma, S. et al. Electroreduction of carbon dioxide to hydrocarbons using bimetallic Cu–Pd catalysts with different mixing patterns. J. Am. Chem. Soc. 139, 47–50 (2017).

    CAS  PubMed  Article  Google Scholar 

  13. 13.

    Chen, X. et al. Controlling speciation during CO2 reduction on Cu-alloy electrodes. ACS Catal. 10, 672–682 (2019).

    Article  CAS  Google Scholar 

  14. 14.

    Li, Y. C. et al. Binding site diversity promotes CO2 electroreduction to ethanol. J. Am. Chem. Soc. 141, 8584–8591 (2019).

    CAS  PubMed  Article  Google Scholar 

  15. 15.

    Morales-Guio, C. G. et al. Improved CO2 reduction activity towards C2+ alcohols on a tandem gold on copper electrocatalyst. Nat. Catal. 1, 764–771 (2018).

    CAS  Article  Google Scholar 

  16. 16.

    Hoang, T. T. H. et al. Nanoporous copper films by additive-controlled electrodeposition: CO2 reduction catalysis. ACS Catal. 7, 3313–3321 (2017).

    CAS  Article  Google Scholar 

  17. 17.

    Li, F. et al. Molecular tuning of CO2-to-ethylene conversion. Nature 577, 509–513 (2020).

    CAS  PubMed  Article  Google Scholar 

  18. 18.

    Wang, Y. et al. Catalyst synthesis under CO2 electroreduction favours faceting and promotes renewable fuels electrosynthesis. Nat. Catal. 3, 98–106 (2019).

    Article  CAS  Google Scholar 

  19. 19.

    Ma, S. et al. One-step electrosynthesis of ethylene and ethanol from CO2 in an alkaline electrolyzer. J. Power Sources 301, 219–228 (2016).

    CAS  Article  Google Scholar 

  20. 20.

    Weekes, D. M. et al. Electrolytic CO2 reduction in a flow cell. Acc. Chem. Res. 51, 910–918 (2018).

    CAS  PubMed  Article  Google Scholar 

  21. 21.

    Schmitt, K. G. & Gewirth, A. A. In situ surface-enhanced Raman spectroscopy of the electrochemical reduction of carbon dioxide on silver with 3,5-diamino-1,2,4-triazole. J. Phys. Chem. C 118, 17567–17576 (2014).

    CAS  Article  Google Scholar 

  22. 22.

    Widrig, C. A., Chung, C. & Porter, M. D. The electrochemical desorption of n-alkanethiol monolayers from polycrystalline Au and Ag electrodes. J. Electroanal. Chem. 310, 335–359 (1991).

    CAS  Article  Google Scholar 

  23. 23.

    Tsakova, V. et al. Electrochemical incorporation of copper in polyaniline layers. Electrochim. Acta 46, 4213–4222 (2001).

    CAS  Article  Google Scholar 

  24. 24.

    Ahn, S. et al. Poly-amide modified copper foam electrodes for enhanced electrochemical reduction of carbon dioxide. ACS Catal. 8, 4132–4142 (2018).

    CAS  Article  Google Scholar 

  25. 25.

    Mingqi, Z., Li, S. & M., C. R. Preparation of Cu nanoclusters within dendrimer templates. J. Am. Chem. Soc. 120, 4877–4878 (1998).

    Article  Google Scholar 

  26. 26.

    Mohtasebi, A. et al. Interfacial charge transfer between phenyl-capped aniline tetramer films and iron oxide surfaces. J. Phys. Chem. C. 120, 29248–29263 (2016).

    CAS  Article  Google Scholar 

  27. 27.

    Sylvestre, J.-P. et al. Surface chemistry of gold nanoparticles produced by laser ablation in aqueous media. J. Phys. Chem. B 108, 16864–16869 (2004).

    CAS  Article  Google Scholar 

  28. 28.

    Schouten, K. J. P. et al. A new mechanism for the selectivity to C1 and C2 species in the electrochemical reduction of carbon dioxide on copper electrodes. Chem. Sci. 2, 1902–1909 (2011).

    CAS  Article  Google Scholar 

  29. 29.

    Kortlever, R. et al. Catalysts and reaction pathways for the electrochemical reduction of carbon dioxide. J. Phys. Chem. Lett. 6, 4073–4082 (2015).

    CAS  PubMed  Article  Google Scholar 

  30. 30.

    Jiang, H. et al. Defect-rich and ultrathin N doped carbon nanosheets as advanced trifunctional metal-free electrocatalysts for the ORR, OER and HER. Energy Environ. Sci. 12, 322–333 (2019).

    CAS  Article  Google Scholar 

  31. 31.

    Khurram, A. et al. Promoting amine-activated electrochemical CO2 conversion with alkali salts. J. Phys. Chem. C 123, 18222–18231 (2019).

    CAS  Article  Google Scholar 

  32. 32.

    Kortunov, P. V., Siskin, M., Paccagnini, M. & Thomann, H. CO2 reaction mechanisms with hindered alkanolamines: control and promotion of reaction pathways. Energy Fuels 30, 1223–1236 (2016).

  33. 33.

    Deng, Y. et al. In situ Raman spectroscopy of copper and copper oxide surfaces during electrochemical oxygen evolution reaction: identification of Cuiii oxides as catalytically active species. ACS Catal. 6, 2473–2481 (2016).

    CAS  Article  Google Scholar 

  34. 34.

    Jiang, S., Klingan, K., Pasquini, C. & Dau, H. New aspects of operando Raman spectroscopy applied to electrochemical CO2 reduction on Cu foams. J. Chem. Phys. 150, 041718 (2019).

    PubMed  Article  CAS  Google Scholar 

  35. 35.

    Frantz, J. D. Raman spectra of potassium carbonate and bicarbonate aqueous fluids at elevated temperatures and pressures: comparison with theoretical simulations. Chem. Geol. 152, 211–225 (1998).

    CAS  Article  Google Scholar 

  36. 36.

    Akemann, W. & Otto, A. The effect of atomic scale surface disorder on bonding and activation of adsorbates: vibrational properties of CO and CO2 on copper. Surf. Sci. 287, 104–109 (1993).

    Article  Google Scholar 

  37. 37.

    Gunathunge, C. M. et al. Spectroscopic observation of reversible surface reconstruction of copper electrodes under CO2 reduction. J. Phys. Chem. C 121, 12337–12344 (2017).

    CAS  Article  Google Scholar 

  38. 38.

    Chernyshova, I. V., Somasundaran, P. & Ponnurangam, S. On the origin of the elusive first intermediate of CO2 electroreduction. Proc. Natl Acad. Sci. USA 115, E9261–E9270 (2018).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  39. 39.

    Firet, N. J. & Smith, W. A. Probing the reaction mechanism of CO2 electroreduction over Ag films via operando infrared spectroscopy. ACS Catal. 7, 606–612 (2016).

    Article  CAS  Google Scholar 

  40. 40.

    Davis, A. R. & Oliver, B. G. A vibrational-spectroscopic study of the species present in the CO2–H2O system. J. Solut. Chem. 1, 329–339 (1972).

    CAS  Article  Google Scholar 

  41. 41.

    Klitzing, R. & Moehwald, H. Proton concentration profile in ultrathin polyelectrolyte films. Langmuir 11, 3554–3559 (1995).

    CAS  Article  Google Scholar 

  42. 42.

    Zhang, Y., Tsitkov, S. & Hess, H. Proximity does not contribute to activity enhancement in the glucose oxidase–horseradish peroxidase cascade. Nat. Commun. 7, 13982 (2016).

    CAS  PubMed  PubMed Central  Article  Google Scholar 

  43. 43.

    Dinh, C.-T. et al. CO2 electroreduction to ethylene via hydroxide-mediated copper catalysis at an abrupt interface. Science 360, 783–787 (2018).

    CAS  PubMed  Article  PubMed Central  Google Scholar 

  44. 44.

    Varela, A. S., Kroschel, M., Reier, T. & Strasser, P. Controlling the selectivity of CO2 electroreduction on copper: the effect of the electrolyte concentration and the importance of the local pH. Catal. Today 260, 8–13 (2016).

    CAS  Article  Google Scholar 

  45. 45.

    Schouten, K. J. P., Pérez Gallent, E. & Koper, M. T. M. The influence of pH on the reduction of CO and CO2 to hydrocarbons on copper electrodes. J. Electroanal. Chem. 716, 53–57 (2014).

    CAS  Article  Google Scholar 

  46. 46.

    Raciti, D., Mao, M., Park, J. H. & Wang, C. Local pH effect in the CO2 reduction reaction on high-surface-area copper electrocatalysts. J. Electrochem. Soc. 165, F799–F804 (2018).

    CAS  Article  Google Scholar 

  47. 47.

    Ma, M. et al. Insights into the carbon balance for CO2 electroreduction on Cu using gas diffusion electrode reactor designs. Energy Environ. Sci. 13, 977–985 (2020).

    CAS  Article  Google Scholar 

  48. 48.

    Xia, C. et al. Continuous production of pure liquid fuel solutions via electrocatalytic CO2 reduction using solid-electrolyte devices. Nat. Energy 4, 776–785 (2019).

    CAS  Article  Google Scholar 

  49. 49.

    Lee, J. et al. Electrochemical CO2 reduction using alkaline membrane electrode assembly on various metal electrodes. J. CO2 Util. 31, 244–250 (2019).

    CAS  Article  Google Scholar 

  50. 50.

    Gabardo, C. M. et al. Continuous carbon dioxide electroreduction to concentrated multi-carbon products using a membrane electrode assembly. Joule 3, 2777–2791 (2019).

    CAS  Article  Google Scholar 

  51. 51.

    Tomas, M. et al. Modification of gas diffusion layers properties to improve water management. Mater. Renew. Sustain. Energy 6, 20 (2017).

  52. 52.

    Yu, S. et al. Study on hydrophobicity loss of the gas diffusion layer in PEMFCs by electrochemical oxidation. RSC Adv. 4, 3852–3856 (2014).

    CAS  Article  Google Scholar 

  53. 53.

    Verma, S. et al. The effect of electrolyte composition on the electroreduction of CO2 to CO on Ag based gas diffusion electrodes. Phys. Chem. Chem. Phys. 18, 7075–7084 (2016).

    CAS  PubMed  Article  Google Scholar 

Download references


The authors gratefully acknowledge the support of the International Institute for Carbon Neutral Energy Research (WPI-I2CNER), sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology. D.A.H., U.O.N. and P.J.A.K. gratefully acknowledge Shell’s New Energy Research and Technology (NERT) programme for providing funding. J.C. and S.C.Z. acknowledge support of the National Science Foundation (NSF CHE-1709718). We thank the School of Chemical Sciences, University of Illinois Mass Spectrometry Laboratory (especially F. Sun and X. Mao) for performing gas chromatography mass spectrometry measurements. We thank R.T. Haasch for performing XPS and the School of Chemical Sciences, University of Illinois Machine Shop for their help in designing the in situ flow cell for the Raman measurements. We also thank the School of Chemical Sciences, University of Illinois NMR Laboratory for their help with the NMR measurements.

Author information




X.C. and N.M.A. prepared the Cu–Pi electrodes and performed the electrochemistry experiments. J.C. synthesized the polymers and performed the NMR experiments. X.C. conducted the SEM and XRD experiments. X.C. and D.A.H. carried out the Raman measurements. R.Z. analysed the XPS data. U.O.N. prepared the anode electrodes. K.E.M. did the contact angle measurements. A.A.G., S.C.Z. and P.J.A.K. conceived the project and supervised the research work. X.C., J.C. and A.A.G. wrote the manuscript with input from the other authors.

Corresponding author

Correspondence to Andrew A. Gewirth.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Notes 1–4, Figs. 1–30 and Tables 1–5.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Chen, X., Chen, J., Alghoraibi, N.M. et al. Electrochemical CO2-to-ethylene conversion on polyamine-incorporated Cu electrodes. Nat Catal 4, 20–27 (2021).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing