Potassium-Promoted Reduction of Cu₂O/Cu(111) by CO

Journal Article · 08 November 2018 · Journal of Physical Chemistry. C

DOI: https://doi.org/10.1021/acs.jpcc.8b07403 · OSTI ID:1559124

Waluyo, Iradwikanari  ^[1]; Mudiyanselage, Kumudu ^[1]; Xu, Fang  ^[1]; An, Wei  ^[1]; Liu, Ping  ^[1]; Boscoboinik, J. Anibal  ^[1]; Rodriguez, José A.  ^[1]; Stacchiola, Dario J.  ^[1]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States)

In situ X-ray photoelectron spectroscopy (XPS), infrared reflection absorption spectroscopy (IRRAS), and scanning tunneling microscopy (STM) were used to study the reduction of potassium-modified Cu₂O/Cu(111) by CO. By following the time evolution of the O 1s peak of Cu₂O, we determined that the apparent activation energy for Cu₂O reduction by 2 × 10^–4 Torr CO is decreased by ~30% in the presence of K. On the K-modified surface, both XPS and IRRAS data show the formation of a surface species identified by IRRAS as carbonate (CO₃^2–), likely forming a K⁺-CO₃^2– complex, which is stable up to 500 K. STM images show that K⁺-CO₃^2– complexes form chains around reduced Cu islands, thereby hindering the mass transfer of Cu atoms and preventing the reconstruction of the surface. Theoretical calculations show that the formation of carbonate on the K-modified “44” Cu₂O structure is thermodynamically favorable compared to the formation of CO₂ on either the bare or K-modified surfaces.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704
• OSTI ID: 1559124
• Report Number(s): BNL-212024-2019-JAAM; TRN: US2000298
• Journal Information: Journal of Physical Chemistry. C, Vol. 123, Issue 13; ISSN 1932-7447
• Publisher: American Chemical SocietyCopyright Statement
• Country of Publication: United States
• Language: English