Journal article
Nature and Distribution of Stable Subsurface Oxygen in Copper Electrodes During Electrochemical CO2 Reduction
Department of Physics, AlbaNova University Center1
2575 Sand Hill Road, Menlo Park, California 940252
LNESS Laboratory and Dipartimento di Fisica3
via Celoria 16, 20133 Milano4
SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering5
Stanford Nano Shared Facilities6
Center for Electron Nanoscopy7
Oxide-derived copper (OD-Cu) electrodes exhibit higher activity than pristine copper during the carbon dioxide reduction reaction (CO2RR) and higher selectivity toward ethylene. The presence of residual subsurface oxygen in OD-Cu has been proposed to be responsible for such improvements, although its stability under the reductive CO2RR conditions remains unclear.
This work sheds light on the nature and stability of subsurface oxygen. Our spectroscopic results show that oxygen is primarily concentrated in an amorphous 1–2 nm thick layer within the Cu subsurface, confirming that subsurface oxygen is stable during CO2RR for up to 1 h at −1.15 V vs RHE. Besides, it is associated with a high density of defects in the OD-Cu structure.
We propose that both low coordination of the amorphous OD-Cu surface and the presence of subsurface oxygen that withdraws charge from the copper sp- and d-bands might selectively enhance the binding energy of CO.
Language: | English |
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Publisher: | American Chemical Society |
Year: | 2017 |
Pages: | 25003-25009 |
ISSN: | 19327455 and 19327447 |
Types: | Journal article |
DOI: | 10.1021/acs.jpcc.7b08278 |