Converting CO2 emissions, powered by renewable electricity, to produce fuels and chemicals provides an elegant route towards a carbon-neutral energy cycle. Progress in the understanding and synthesis of Cu catalysts has spurred the explosive development of electrochemical CO2 reduction (CO2RR) technology to produce hydrocarbons and oxygenates; however, Cu, as the predominant catalyst, often exhibits limited selectivity and activity towards a specific product, leading to low productivity and substantial post-reaction purification. Here, we present a single-atom Pb-alloyed Cu catalyst (Pb1Cu) that can exclusively (~96% Faradaic efficiency) convert CO2 into formate with high activity in excess of 1 A cm–2. The Pb1Cu electrocatalyst converts CO2 into formate on the modulated Cu sites rather than on the isolated Pb. In situ spectroscopic evidence and theoretical calculations revealed that the activated Cu sites of the Pb1Cu catalyst regulate the first protonation step of the CO2RR and divert the CO2RR towards a HCOO* path rather than a COOH* path, thus thwarting the possibility of other products. We further showcase the continuous production of a pure formic acid solution at 100 mA cm–2 over 180 h using a solid electrolyte reactor and Pb1Cu.
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C.X. acknowledges the University of Electronic Science and Technology of China (UESTC) for startup funding (A1098531023601264) and the NSFC (22102018 and 52171201). J.Z. acknowledges the National Key Research and Development Program of China (2019YFA0405600), the National Science Fund for Distinguished Young Scholars (21925204), the NSFC (U19A2015), the Fundamental Research Funds for the Central Universities, the Provincial Key Research and Development Program of Anhui (202004a05020074), the DNL Cooperation Fund, CAS (DNL202003) and the USTC Research Funds of the Double First-Class Initiative (YD2340002002). This work was partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication. J.X. acknowledges the Ministry of Science and Technology of China (2018YFA0704503), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB36030200), the NSFC (91845103), the DNL Cooperation Fund, CAS (DNL202003) and the LiaoNing Revitalization Talents Program (XLYC1907099). T.Z. acknowledges the China Postdoctoral Science Foundation (2019TQ0300 and 2020M671890) and the NSFC (22005291). A.L. acknowledges the Beijing Outstanding Young Scientist Program (BJJWZYJH01201914430039). The authors thank Beijing Synchrotron Radiation Facility (beam line BL1W1B) and Taiwan Photon Source (beamline 44A) for providing beam time.
The authors declare no competing interests.
Peer review information Nature Nanotechnology thanks Miao Zhong and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Zheng, T., Liu, C., Guo, C. et al. Copper-catalysed exclusive CO2 to pure formic acid conversion via single-atom alloying. Nat. Nanotechnol. (2021). https://doi.org/10.1038/s41565-021-00974-5