Atomic‐Scale Spacing between Copper Facets for the Electrochemical Reduction of Carbon Dioxide. Issue 10 (30th January 2020)

• Record Type: Journal Article
• Authors: Jeong, Hyung Mo; Kwon, Youngkook; Won, Jong Ho; Lum, Yanwei; Cheng, Mu‐Jeng; Kim, Kwang Ho; Head‐Gordon, Martin; Kang, Jeung Ku
• Is Part Of: Advanced energy materials. Volume 10:Issue 10(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-01-30
• Subjects: 3D tomography -- Cu nanoparticles -- C2+ fuels -- CO2 reduction, C–C coupling reactions; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.201903423
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Copper (Cu) offers a means for producing value‐added fuels through the electrochemical reduction of carbon dioxide (CO2 ), i.e., the CO2 reduction reaction (CO2 RR), but designing Cu catalysts with significant Faradaic efficiency to C2+ products remains as a great challenge. This work demonstrates that the high activity and selectivity of Cu to C2+ products can be achieved by atomic‐scale spacings between two facets of Cu particles. These spacings are created by lithiating CuO x particles, removing lithium oxides formed, and electrochemically reducing CuO x to metallic Cu. Also, the range of spacing ( d s ) is confirmed via the 3D tomographs using the Cs‐corrected scanning transmission electron microscopy (3D tomo‐STEM), and the operando X‐ray absorption spectra show that oxidized Cu reduces to the metallic state during the CO2 RR. Moreover, control of d s to 5–6 Å allows a current density exceeding that of unmodified CuO x nanoparticles by about 12 folds and a Faradaic efficiency of ≈80% to C2+ . Density functional theory calculations support that d s of 5–6 Å maximizes the binding energies of CO2 reduction intermediates and promotes C–C coupling reactions. Consequently, this study suggests that control of d s can be used to realize the high activity and C2+ product selectivity for the CO2 RR. Abstract : It is reported that Cu nanoparticles with the atomic‐scale spacings of <1 nm enable a current density exceeding that of pristine nanoparticles by ≈12 fold and a Faradaic efficiency of nearly 80% to C2+ products, thereby implying that the control of atomic‐scale spacings would pave a new route to realize high performance in the activity and C2+ product selectivity for the CO2 reduction reaction (CO2 RR).