C–C coupling is a critical step of CO2 fixation in constructing the carbon skeleton of value-added multicarbon products. The Wood–Ljungdahl pathway is an efficient natural process through which microbes transform CO2 into methyl and carbonyl groups and subsequently couple them together. This asymmetric coupling mechanism remains largely unexplored in inorganic CO2 electroreduction. Here we experimentally validate the asymmetric coupling pathway through isotope-labelled co-reduction experiments on a Cu surface where 13CH3I and 12CO are co-fed externally as the methyl and the carbonyl source, respectively. Isotope-labelled multicarbon oxygenates were detected, which confirms an electrocatalytic asymmetric coupling on the Cu surface. We further employed tandem Cu–Ag nanoparticle systems in which *CHx and *CO intermediates can be generated to achieve asymmetric C–C coupling for a practical CO2 electroreduction. We found that the production of multicarbon oxygenates is correlated with the generation rate of two intermediate indicators, CH4 and CO. By aligning their rates, the oxygenates generation rate can be maximized.
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This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences and Biosciences Division of the US Department of Energy under contract DE-AC02-05CH11231, FWP CH030201 (Catalysis Research Program). STEM–EDX and XPS were conducted using facilities at the Molecular Foundry. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences of the US Department of Energy under contract no. DE-AC02-05CH11231. The STEM–EELS work made use of the TEM facilities (Nion UltraSTEM) at the Cornell Center for Materials Research (CCMR), which are supported through the National Science Foundation Materials Research Science and Engineering Center (NSF MRSEC) program (DMR-1719875). We thank the TEM technical support of R. Dhall and K. Bustillo at NCEM and of M. Thomas at Cornell. We thank H. Celik and UC Berkeley’s NMR facility in the College of Chemistry (CoC-NMR) for spectroscopic assistance. Instruments in the CoC-NMR are supported in part by NIH S10OD024998. C.C. and J.J. gratefully acknowledge support from Suzhou Industrial Park Scholarships. S.Y. acknowledges support from a Samsung Scholarship. Y.Y. acknowledges support from a Miller Research Fellowship. P.-C.C. acknowledges support from a Kavli ENSI Heising-Simons Fellowship.
The authors declare no competing interests.
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Chen, C., Yu, S., Yang, Y. et al. Exploration of the bio-analogous asymmetric C–C coupling mechanism in tandem CO2 electroreduction. Nat Catal 5, 878–887 (2022). https://doi.org/10.1038/s41929-022-00844-w