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Unlocking direct CO2 electrolysis to C3 products via electrolyte supersaturation


The electroreduction of CO2 has recently achieved notable progress in the formation of C2 products such as ethylene and ethanol. However, the direct synthesis of C3 products is considerably limited by the C2–C1 coupling reaction and the faradaic efficiency has remained low. Here we present a supersaturation strategy for the electrosynthesis of 2-propanol from CO2 in highly carbonated electrolytes. By controlling the CO2 concentration above the saturation limit, we have developed a co-electrodeposition method with suppressed galvanic replacement to obtain a CuAg alloy catalyst. In supersaturated conditions, the alloy achieved high performance for the production of 2-propanol with a faradaic efficiency of 56.7% and at a specific current density of 59.3 mA cm−2. Our investigations revealed that the presence of dispersed Ag atoms in Cu weakens the surface binding of intermediates in the middle position of the alkyl chain and strengthens the C–O bonds, which favours the formation of 2-propanol over 1-propanol.

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Fig. 1: Operando deposition and structure characterization of CuAg bimetallic catalysts.
Fig. 2: Surface facet and coordination environment characterization of CuAg bimetallic catalysts.
Fig. 3: CO2RR performance in an H-cell under atmospheric pressure CO2-supersaturated electrolyte.
Fig. 4: CO2RR activity maps and the stability measurement.
Fig. 5: Investigations of the CO2 reduction reaction mechanism using ex situ and operando spectroscopy.
Fig. 6: Theoretical calculations of the C–C coupling and the formation of 2-propanol.
Fig. 7: CO2RR performance in high-pressure electrolyser under elevated CO2 concentration.
Fig. 8: CO2RR stability measurement and quantity and formation rate of 2-propanol.

Data availability

All data are available in the public Figshare repository ( or from the corresponding author upon reasonable request. Source data are provided with this paper.

Code availability

All code used within the Article is available in the public Figshare repository ( or from the corresponding author upon reasonable request.


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D.V., K.Q. and H.W. acknowledge funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant no. 804320). This work was also supported by the Laboratoire d’Excellence sur la Chimie des Systèmes Moléculaires et Interfaciaux (LabEx CheMISyst). K.Q. and Y.Z. acknowledge financial support from the China Postdoctoral Science Foundation (2018M633127) and the Natural Science Foundation of Guangdong Province (2018A030310602). L.L. acknowledges funding from the Andalusian regional government (FEDER-UCA-18-106613), the European Union’s Horizon 2020 research and innovation programme (823717-ESTEEM3) and the Spanish Ministerio de Economia y Competitividad (PID2019-107578GA-I00). X.C. acknowledges funding from the National Natural Science Foundation of China (grant nos. 12034002 and 22279044). We thank the SOLEIL Synchrotron and A. Zitolo for allocating beamtime at beamline Samba within proposal number 20200732. We thank E. Oliviero and F. Godiard from the University of Montpellier for their help with the TEM analysis. P. Montels and D. Valenza are acknowledged for their technical support. We thank X. Tao from the University of Extremadura for the MATLAB coding. Part of the S/TEM investigations was performed at the National Facility ELECMI ICTS (‘Division de Microscopia Electronica’, Universidad de Cadiz, DME-UCA). This work was granted access to the HPC resources of IDRIS under the allocation 2021-2022-A0110913046 made by GENCI.

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Authors and Affiliations



D.V. and K.Q. designed and directed the research. K.Q., Y.Z., H.W. and Y.Z. synthesized the materials and performed the materials property characterization. N.O., W.W. and J.L. carried out and analysed the DFT calculations. E.P. and C.S. carried out the liquid NMR spectroscopy measurements. L.L., X.C. and Y.W. performed the TEM characterization and analysed the data. K.Q. and D.V. wrote the manuscript. K.Q., J.L., G.J., J.W., J.M. and J.F. performed the hXAS measurements and fitting. D.V. supervised the project and established the final version of the paper. All authors contributed to the manuscript and have approved the final version of the manuscript.

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Correspondence to Damien Voiry.

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Nature Catalysis thanks Hao Ming Chen for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–68, tables 1–18 and notes 1–41.

Supplementary Code 1

MATLAB code for calculating the CO2 species in the electrolyte under different pressures.

Supplementary Data

DFT coordinates.

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Source data of Fig. 1a–d.

Source Data Fig. 2

Source data of Fig. 2c–e.

Source Data Fig. 3

Source data of Fig. 3a–d.

Source Data Fig. 4

Source data of Fig. 4a–d, f and g.

Source Data Fig. 5

Source data of Fig. 5b–f.

Source Data Fig. 6

Source data of Fig. 6c,d.

Source Data Fig. 7

Source data of Fig. 7a–c.

Source Data Fig. 8

Source data of Fig. 8a–c.

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Qi, K., Zhang, Y., Onofrio, N. et al. Unlocking direct CO2 electrolysis to C3 products via electrolyte supersaturation. Nat Catal 6, 319–331 (2023).

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