Letter | Published:

Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper

Nature volume 508, pages 504507 (24 April 2014) | Download Citation



The electrochemical conversion of CO2 and H2O into liquid fuel is ideal for high-density renewable energy storage and could provide an incentive for CO2 capture. However, efficient electrocatalysts for reducing CO2 and its derivatives into a desirable fuel1,2,3 are not available at present. Although many catalysts4,5,6,7,8,9,10,11 can reduce CO2 to carbon monoxide (CO), liquid fuel synthesis requires that CO is reduced further, using H2O as a H+ source. Copper (Cu) is the only known material with an appreciable CO electroreduction activity, but in bulk form its efficiency and selectivity for liquid fuel are far too low for practical use. In particular, H2O reduction to H2 outcompetes CO reduction on Cu electrodes unless extreme overpotentials are applied, at which point gaseous hydrocarbons are the major CO reduction products12,13. Here we show that nanocrystalline Cu prepared from Cu2O (‘oxide-derived Cu’) produces multi-carbon oxygenates (ethanol, acetate and n-propanol) with up to 57% Faraday efficiency at modest potentials (–0.25 volts to –0.5 volts versus the reversible hydrogen electrode) in CO-saturated alkaline H2O. By comparison, when prepared by traditional vapour condensation, Cu nanoparticles with an average crystallite size similar to that of oxide-derived copper produce nearly exclusive H2 (96% Faraday efficiency) under identical conditions. Our results demonstrate the ability to change the intrinsic catalytic properties of Cu for this notoriously difficult reaction by growing interconnected nanocrystallites from the constrained environment of an oxide lattice. The selectivity for oxygenates, with ethanol as the major product, demonstrates the feasibility of a two-step conversion of CO2 to liquid fuel that could be powered by renewable electricity.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. Frontiers, opportunities, and challenges in biochemical and chemical catalysis of CO2 fixation. Chem. Rev. 113, 6621–6658 (2013)

  2. 2.

    , & Electrochemical conversion of CO2 to useful chemicals: current status, remaining challenges, and future opportunities. Curr. Opin. Chem. Eng. 2, 191–199 (2013)

  3. 3.

    & in Carbon Dioxide as Chemical Feedstock (ed. Aresta, M.) 291–316 (Wiley, 2010)

  4. 4.

    , & Catalysis of the electrochemical reduction of carbon dioxide. Chem. Soc. Rev. 42, 2423–2436 (2013)

  5. 5.

    , , & Electrocatalytic and homogeneous approaches to conversion of CO2 to liquid fuels. Chem. Soc. Rev. 38, 89–99 (2009)

  6. 6.

    , , & A local proton source enhances CO2 electroreduction to CO by a molecular Fe catalyst. Science 338, 90–94 (2012)

  7. 7.

    in Modern Aspects of Electrochemistry Vol. 42 (eds Vayenas, C. G., White, R. E. & Gamboa-Aldeco, M. E.) 89–189 (Springer, 2008)

  8. 8.

    , & Aqueous CO2 reduction at very low overpotential on oxide-derived Au nanoparticles. J. Am. Chem. Soc. 134, 19969–19972 (2012)

  9. 9.

    , , , & Nitrogen-based catalysts for the electrochemical reduction of CO2 to CO. J. Am. Chem. Soc. 134, 19520–19523 (2012)

  10. 10.

    & Selective conversion of CO2 to CO with high efficiency using an inexpensive bismuth-based electrocatalyst. J. Am. Chem. Soc. 135, 8798–8801 (2013)

  11. 11.

    & Electrolysis of carbon dioxide in solid oxide electrolysis cells. J. Power Sources 193, 349–358 (2009)

  12. 12.

    , , & Electrochemical reduction of CO at a copper electrode. J. Phys. Chem. B 101, 7075–7081 (1997)

  13. 13.

    , , & Electroreduction of CO to CH4 and C2H4 at a copper electrode in aqueous solutions at ambient temperature and pressure. J. Am. Chem. Soc. 109, 5022–5023 (1987)

  14. 14.

    , & A review of the aqueous electrochemical reduction of CO2 to hydrocarbons at copper. J. Electroanal. Chem. 594, 1–19 (2006)

  15. 15.

    , , & Selective formation of C2 compounds from electrochemical reduction of CO2 at a series of copper single crystal electrodes. J. Phys. Chem. B 106, 15–17 (2002)

  16. 16.

    & Theoretical considerations on the electroreduction of CO to C2 species on Cu(100) electrodes. Angew. Chem. Int. Ed. 52, 7282–7285 (2013)

  17. 17.

    , , & Two pathways for the formation of ethylene in CO reduction on single-crystal copper electrodes. J. Am. Chem. Soc. 134, 9864–9867 (2012)

  18. 18.

    , , & New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces. Energy Environ. Sci. 5, 7050–7059 (2012)

  19. 19.

    , & Formation of hydrocarbons in the electrochemical reduction of carbon dioxide at a copper electrode in aqueous solution. J. Chem. Soc. Faraday Trans. I 85, 2309–2326 (1989)

  20. 20.

    & CO2 reduction at low overpotential on Cu electrodes resulting from the reduction of thick Cu2O films. J. Am. Chem. Soc. 134, 7231–7234 (2012)

  21. 21.

    Electrode Kinetics for Chemists, Engineers, and Materials Scientists Ch. 1 1–8 (Wiley, 1993)

  22. 22.

    , & Adsorption of CO, intermediately formed in electrochemical reduction of CO2, at a copper electrode. J. Chem. Soc. Faraday Trans. 87, 125–128 (1991)

  23. 23.

    , & Insights into C–C coupling in CO2 electroreduction on copper electrodes. ChemCatChem 5, 737–742 (2013)

  24. 24.

    et al. Infrared spectroscopic and voltammetric study of adsorbed CO on stepped surfaces of copper monocrystalline electrodes. Electrochim. Acta 50, 2475–2485 (2005)

  25. 25.

    et al. Role of axially coordinated surface sites for electrochemically controlled carbon monoxide adsorption on single crystal copper electrodes. Phys. Chem. Chem. Phys. 13, 5242–5251 (2011)

  26. 26.

    , & Chevron defect at the intersection of grain boundaries with free surfaces in Au. Phys. Rev. Lett. 89, 085502 (2002)

  27. 27.

    , , , & Electrocatalytic activity and interconnectivity of Pt nanoparticles on multiwalled carbon nanotubes for fuel cells. J. Phys. Chem. C 113, 18935–18945 (2009)

  28. 28.

    et al. On the influence of the metal loading on the structure of carbon-supported PtRu catalysts and their electrocatalytic activities in CO and methanol electrooxidation. Phys. Chem. Chem. Phys. 9, 5476–5489 (2007)

  29. 29.

    Status and future opportunities for conversion of synthesis gas to liquid fuels. Fuel 73, 1243–1279 (1994)

  30. 30.

    , & Heterogeneous catalytic conversion of dry syngas to ethanol and higher alcohols on Cu-based catalysts. ACS Catal. 1, 641–656 (2011)

  31. 31.

    , & Surface interaction of benzoic-acid with a copper electrode. Electrochim. Acta 40, 1717–1721 (1995)

  32. 32.

    CRC. Handbook of Chemistry and Physics 9th edn, section 5 (CRC, 2013).

Download references


We thank Stanford University and the NSF (CHE-1266401) for support of this work. C.W.L. gratefully acknowledges an NSF Predoctoral Fellowship. A portion of this work was performed at NCEM, which is supported by the Office of Science, Office of Basic Energy Sciences of the US Department of Energy under contract number DE-AC02-05CH11231. We thank M. Toney and B. Shyam for assistance with grazing incidence X-ray diffraction performed at SSRL, a national user facility operated by Stanford University on behalf of the Office of Basic Energy Sciences of the US Department of Energy.

Author information


  1. Department of Chemistry, Stanford University, Stanford 94305, California

    • Christina W. Li
    •  & Matthew W. Kanan
  2. National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley 94720, California

    • Jim Ciston


  1. Search for Christina W. Li in:

  2. Search for Jim Ciston in:

  3. Search for Matthew W. Kanan in:


C.W.L. and M.W.K. designed the experiments. C.W.L. prepared and characterized all electrodes and performed all electrochemical experiments; J.C. obtained all TEM images; C.W.L. and M.W.K. wrote the manuscript. All authors contributed to the overall scientific interpretation and edited the manuscript.

Competing interests

C.W.L. and M.W.K. have filed a patent application (WO 2013-US25791, US) covering oxide-derived Cu and other oxide-derived catalysts for electrochemical fuel synthesis.

Corresponding author

Correspondence to Matthew W. Kanan.

Extended data

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.