Electrochemical conversion of CO2 into liquid fuels, powered by renewable electricity, offers one means to address the need for the storage of intermittent renewable energy. Here we present a cooperative catalyst design of molecule–metal catalyst interfaces with the goal of producing a reaction-intermediate-rich local environment, which improves the electrosynthesis of ethanol from CO2 and H2O. We implement the strategy by functionalizing the copper surface with a family of porphyrin-based metallic complexes that catalyse CO2 to CO. Using density functional theory calculations, and in situ Raman and operando X-ray absorption spectroscopies, we find that the high concentration of local CO facilitates carbon–carbon coupling and steers the reaction pathway towards ethanol. We report a CO2-to-ethanol Faradaic efficiency of 41% and a partial current density of 124 mA cm−2 at −0.82 V versus the reversible hydrogen electrode. We integrate the catalyst into a membrane electrode assembly-based system and achieve an overall energy efficiency of 13%.
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The datasets generated during, and/or analysed during, the present study, are available from the corresponding author on reasonable request.
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The authors acknowledge funding support from Suncor Energy, the Ontario Research fund and the Natural Sciences and Engineering Research Council (NSERC). DFT computations were performed on the IBM BlueGene/Q supercomputer with support from the Niagara supercomputer at the SciNet HPC Consortium and the Southern Ontario Smart Computing Innovation Platform (SOSCIP). SciNet is funded by the Canada Foundation for Innovation, the Government of Ontario’s Ontario Research Fund – Research Excellence, and the University of Toronto. SOSCIP is funded by the Federal Economic Development Agency of Southern Ontario, the Province of Ontario, IBM Canada, Ontario Centres of Excellence, Mitacs and 15 Ontario academic member institutions. This research used synchrotron resources of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy Office of Science by Argonne National Laboratory and was supported by the US Department of Energy under contract no. DE-AC02-06CH11357 and the Canadian Light Source and its funding partners. F.L. thanks H.T.L. for ICP–MS measurement. J.L. acknowledges the Banting Postdoctoral Fellowships programme. C.G. acknowledges the NSERC Postdoctoral Fellowships programme. D.S. acknowledges the NSERC E.W.R. Steacie Memorial Fellowship.
The authors declare no competing interests.
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Li, F., Li, Y.C., Wang, Z. et al. Cooperative CO2-to-ethanol conversion via enriched intermediates at molecule–metal catalyst interfaces. Nat Catal 3, 75–82 (2020). https://doi.org/10.1038/s41929-019-0383-7