The discovery of materials for the electrochemical transformation of carbon dioxide into liquid fuels has the potential to impact large-scale storage of renewable energies and reduce carbon emissions. Here, we report the discovery of an electrocatalyst composed of gold nanoparticles on a polycrystalline copper foil (Au/Cu) that is highly active for CO2 reduction to alcohols. At low overpotentials, the Au/Cu electrocatalyst is over 100 times more selective for the formation of products containing C–C bonds versus methane or methanol, largely favouring the generation of alcohols over hydrocarbons. A combination of electrochemical testing and transport modelling supports the hypothesis that CO2 reduction on gold generates a high CO concentration on nearby copper, where CO is further reduced to alcohols such as ethanol and n-propanol under locally alkaline conditions. The bimetallic Au/Cu electrocatalyst exhibits synergistic activity and selectivity superior to gold, copper or AuCu alloys, and opens new possibilities for the development of CO2 reduction electrodes exploiting tandem catalysis mechanisms.
Subscribe to Journal
Get full journal access for 1 year
only $8.25 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The data that support the results and other findings of this study are available from the corresponding authors upon reasonable request.
Whipple, D. & Kenis, P. Prospects of CO2 utilization via direct heterogeneous electrochemical reduction. J. Phys. Chem. Lett. 1, 3451–3458 (2010).
Arakawa, H. et al. Catalysis research of relevance to carbon management: progress, challenges, and opportunities. Chem. Rev. 101, 953–996 (2001).
Qiao, J., Liu, Y., Hong, F. & Zhang, J. A review of catalysts for the electroreduction of carbon dioxide to produce low-carbon fuels. Chem. Soc. Rev. 43, 631–675 (2014).
Hori, Y., Vayenas, C., White, R. & Gamboa-Aldeco, M. Electrochemical CO2 reduction on metal electrodes. Mod. Aspects Electroc. 42, 89–189 (2008).
Kuhl, K. et al. Electrocatalytic conversion of carbon dioxide to methane and methanol on transition metal surfaces. J. Am. Chem. Soc. 136, 14107–14113 (2014).
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).
Hatsukade, T., Kuhl, K., Cave, E., Abram, D. & Jaramillo, T. Insights into the electrocatalytic reduction of CO2 on metallic silver surfaces. Phys. Chem. Chem. Phys. 16, 13814–13819 (2014).
Torelli, D. et al. Nickel–gallium-catalyzed electrochemical reduction of CO2 to highly reduced products at low overpotentials. ACS Catal. 6, 2100–2104 (2016).
Hori, Y. & Murata, A. Electrochemical evidence of intermediate formation of adsorbed CO in cathodic reduction of CO2 at a nickel electrode. Electrochim. Acta 35, 1777–1780 (1990).
Song, Y. et al. High-selectivity electrochemical conversion of CO2 to ethanol using a copper nanoparticle/N-doped graphene electrode. ChemistrySelect 1, 6055–6061 (2016).
Hoang, T., Ma, S., Gold, J., Kenis, P. & Gewirth, A. Nanoporous copper films by additive-controlled electrodeposition: CO2 reduction catalysis. ACS Catal. 7, 3313–3321 (2017).
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).
Li, C., Ciston, J. & Kanan, M. Electroreduction of carbon monoxide to liquid fuel on oxide-derived nanocrystalline copper. Nature 508, 504–507 (2014).
Verdaguer-Casadevall, A. et al. Probing the active surface sites for CO reduction on oxide-derived copper electrocatalysts. J. Am. Chem. Soc. 137, 9808–9811 (2015).
Ren, D., Ang, B. & Yeo, B. Tuning the selectivity of carbon dioxide electroreduction toward ethanol on oxide-derived CuxZn catalysts. ACS Catal. 6, 8239–8247 (2016).
Clark, E. L., Hahn, C., Jaramillo, T. F. & Bell, A. T. Electrochemical CO2 reduction over compressively strained CuAg surface alloys with enhanced multi-carbon oxygenate selectivity. J. Am. Chem. Soc. 139, 15848–15857 (2017).
Sun, H., Yu, M., Wang, G., Sun, X. & Lian, J. Temperature-dependent morphology evolution and surface plasmon absorption of ultrathin gold island films. J. Phys. Chem. C 116, 9000–9008 (2012).
Guisbiers, G. et al. Gold-copper nano-alloy, "Tumbaga", in the era of nano: phase diagram and segregation. Nano Lett. 14, 6718–6726 (2014).
Lum, Y. & Ager Joel, W. Stability of residual oxides in oxide‐derived copper catalysts for electrochemical CO2 reduction investigated with 18O labeling. Angew. Chem. Int. Ed. 57, 551–554 (2017).
Ikemiya, N., Kubo, T. & Hara, S. In-situ AFM observations of oxide film formation on Cu(111) and Cu(100) surfaces under aqueous alkaline-solutions. Surf. Sci. 323, 81–90 (1995).
Mistry, H. et al. Highly selective plasma-activated copper catalysts for carbon dioxide reduction to ethylene. Nat. Commun. 7, 12123 (2016).
Eilert, A. et al. Subsurface oxygen in oxide-derived copper electrocatalysts for carbon dioxide reduction. J. Phys. Chem. Lett. 8, 285–290 (2017).
Manthiram, K., Surendranath, Y. & Alivisatos, A. Dendritic assembly of gold nanoparticles during fuel-forming electrocatalysis. J. Am. Chem. Soc. 136, 7237–7240 (2014).
Wang, J. et al. Formation, migration, and reactivity of Au–CO complexes on gold surfaces. J. Am. Chem. Soc. 138, 1518–1526 (2016).
Kim, Y., Baricuatro, J., Javier, A., Gregoire, J. & Soriaga, M. The evolution of the polycrystalline copper surface, first to Cu(111) and then to Cu(100), at a fixed CO2RR potential: a study by operand EC-STM. Langmuir 30, 15053–15056 (2014).
Papanicolaou, N. & Evangelakis, G. in Surface Diffusion (ed. Tringides, M. C.) 75–81 (NATO ASI Series B 360, Springer, Boston, MA, 1997).
Balerna, A. et al. Extended X-ray absorption fine-structure and near-edge-structure studies on evaporated small clusters of Au. Phys. Rev. B 31, 5058–5065 (1985).
Cave, E. R. et al. Electrochemical CO2 reduction on Au surfaces: mechanistic aspects regarding the formation of major and minor products. Phys. Chem. Chem. Phys. 19, 15856–15863 (2017).
Benck, J., Hellstern, T., Kibsgaard, J., Chakthranont, P. & Jaramillo, T. Catalyzing the hydrogen evolution reaction (HER) with molybdenum sulfide nanomaterials. ACS Catal. 4, 3957–3971 (2014).
Jia, F., Yu, X. & Zhang, L. Enhanced selectivity for the electrochemical reduction of CO2 to alcohols in aqueous solution with nanostructured Cu–Au alloy as catalyst. J. Power Sources 252, 85–89 (2014).
Andrews, E. et al. Electrochemical reduction of CO2 at Cu nanocluster / (1010) ZnO electrodes. J. Electrochem. Soc. 160, H841–H846 (2013).
Peterson, A. & Norskov, J. Activity descriptors for CO2 electroreduction to methane on transition-metal catalysts. J. Phys. Chem. Lett. 3, 251–258 (2012).
Liu, X. et al. Understanding trends in electrochemical carbon dioxide reduction rates. Nat. Commun. 8, 15438 (2017).
Kim, D. et al. Electrochemical activation of CO2 through atomic ordering transformations of AuCu nanoparticles. J. Am. Chem. Soc. 139, 8329–8336 (2017).
Kim, D., Resasco, J., Yu, Y., Asiri, A. & Yang, P. Synergistic geometric and electronic effects for electrochemical reduction of carbon dioxide using gold–copper bimetallic nanoparticles. Nat. Commun. 5, 5948 (2014).
Mistry, H., Reske, R., Strasser, P. & Roldan Cuenya, B. Size-dependent reactivity of gold–copper bimetallic nanoparticles during CO2 electroreduction. Catal. Today 288, 30–36 (2017).
Monzo, J. et al. Enhanced electrocatalytic activity of Au@Cu core@shell nanoparticles towards CO2 reduction. J. Mater. Chem. A 3, 23690–23698 (2015).
Gupta, N., Gattrell, M. & MacDougall, B. Calculation for the cathode surface concentrations in the electrochemical reduction of CO2 in KHCO3 solutions. J. Appl. Electrochem. 36, 161–172 (2006).
Goodpaster, J., Bell, A. & Head-Gordon, M. Identification of possible pathways for C–C bond formation during electrochemical reduction of CO2: new theoretical insights from an improved electrochemical model. J. Phys. Chem. Lett. 7, 1471–1477 (2016).
Montoya, J., Peterson, A. & Norskov, J. Insights into CC coupling in CO2 electroreduction on copper electrodes. ChemCatChem 5, 737–742 (2013).
Perez-Gallent, E., Figueiredo, M., Calle-Vallejo, F. & Koper, M. Spectroscopic observation of a hydrogenated CO dimer intermediate during CO reduction on Cu(100) electrodes. Angew. Chem. Int. Ed. 56, 3621–3624 (2017).
Hahn, C. et al. Engineering Cu surfaces for the electrocatalytic conversion of CO2: controlling selectivity toward oxygenates and hydrocarbons. Proc. Natl Acad. Sci. USA 114, 5918–5923 (2017).
Akhade, S. et al. Poisoning effect of adsorbed CO during CO2 electroreduction on late transition metals. Phys. Chem. Chem. Phys. 16, 20429–20435 (2014).
Hori, Y., Murata, A., Ito, S.-y, Yoshinami, Y. & Koga, O. Nickel and iron modified copper electrode for electroreduction of CO2 by in-situ electrodeposition. Chem. Lett. 18, 1567–1570 (1989).
He, J., Johnson Noah, J. J., Huang, A. & Berlinguette Curtis, P. Electrocatalytic alloys for CO2 reduction. ChemSusChem 11, 48–57 (2017).
Watanabe, M., Shibata, M., Kato, A., Azuma, M. & Sakata, T. Design of alloy electrocatalysts for CO2 reduction: III. The selective and reversible reduction of CO2 on Cu alloy electrodes. J. Electrochem. Soc. 138, 3382–3389 (1991).
Chen, C. S., Wan, J. H. & Yeo, B. S. Electrochemical reduction of carbon dioxide to ethane using nanostructured Cu2O-derived copper catalyst and palladium(II) chloride. J. Phys. Chem. C 119, 26875–26882 (2015).
Varela, A. S. et al. CO2 electroreduction on well-defined bimetallic surfaces: Cu overlayers on Pt(111) and Pt(211). J. Phys. Chem. C 117, 20500–20508 (2013).
Verma, S., Lu, X., Ma, S., Masel, R. & Kenis, P. 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).
Resasco, J., Lum, Y., Clark, E., Zeledon, J. & Bell, A. Effects of anion identity and concentration on electrochemical reduction of CO2. ChemElectroChem 5, 1064–1072 (2018).
Resasco, J. et al. Promoter effects of alkali metal cations on the electrochemical reduction of carbon dioxide. J. Am. Chem. Soc. 139, 11277–11287 (2017).
Hori, Y., Takahashi, R., Yoshinami, Y. & Murata, A. Electrochemical reduction of CO at a copper electrode. J. Phys. Chem. B 101, 7075–7081 (1997).
Varela, A. et al. pH effects on the selectivity of the electrocatalytic CO2 reduction on graphene-embedded Fe–N–C motifs: bridging concepts between molecular homogeneous and solid-state heterogeneous catalysis. ACS Energy Lett. 3, 812–817 (2018).
Schouten, K., Gallent, E. & Koper, M. The influence of pH on the reduction of CO and CO2 to hydrocarbons on copper electrodes. J. Electroanal. Chem. 716, 53–57 (2014).
Billy, J. & Co, A. Experimental parameters influencing hydrocarbon selectivity during the electrochemical conversion of CO2. ACS Catal. 7, 8467–8479 (2017).
This material is based on work performed by the Joint Center for Artificial Photosynthesis, a Department of Energy (DOE) Energy Innovation Hub, as follows: the development of electrochemical testing was supported through the Office of Science of the US DOE under award number DE-SC0004993; the development of the gold on copper morphology and the physical characterization of catalysts were supported by the National Science Foundation under grant number 1066515 and by the Global Climate Energy Project at Stanford University. The work of C.G.M.-G. was supported by the Swiss National Science Foundation (grant number P2ELP2_168600). E.R.C. acknowledges support from the National Science Foundation Graduate Research Fellowship under grant number DGE-1147470 and from a Ford Foundation Fellowship. L.W. thanks the Knut and Alice Wallenberg Foundation for financial support. We thank the Stanford NMR Facility and the Stanford Nano Shared Facilities for use of their shared facilities. In particular, we thank T. Carver from the Flexible Cleanroom at the Stanford Nano Shared Facilities for his role in depositing the gold nanoparticles and A. Vailionis at the Stanford Nanocharacterization Laboratory for assistance with the XRD measurements.
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Morales-Guio, C.G., Cave, E.R., Nitopi, S.A. et al. Improved CO2 reduction activity towards C2+ alcohols on a tandem gold on copper electrocatalyst. Nat Catal 1, 764–771 (2018). https://doi.org/10.1038/s41929-018-0139-9
Nano Energy (2021)
Promoting carbon dioxide electroreduction toward ethanol through loading Au nanoparticles on hollow Cu2O nanospheres
Catalysis Today (2021)
Transactions of Tianjin University (2021)
Applied Surface Science (2021)
Advanced Energy Materials (2021)