TY - JOUR
T1 - Structurally Accurate Model for the "29"-Structure of CuxO/Cu(111)
T2 - A DFT and STM Study
AU - Therrien, Andrew J.
AU - Zhang, Renqin
AU - Lucci, Felicia R.
AU - Marcinkowski, Matthew D.
AU - Hensley, Alyssa
AU - McEwen, Jean Sabin
AU - Sykes, E. Charles H.
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/5/26
Y1 - 2016/5/26
N2 - Copper is a common catalyst for many important chemical reactions including low-temperature water gas shift, selective catalytic reduction of NOx, methanol synthesis, methanol steam reforming, and partial oxidation of methanol. The degree of surface oxidation, or the oxidation state of the active site, during these reactions has been debated and is known to have a large influence on the reaction rates. Therefore, elucidating the atomic-scale structure of copper surface oxides is an important step toward a fuller understanding of reaction mechanisms in heterogeneous catalysis. The so-called "29" monolayer oxide film is a common intermediate in the oxidation of Cu(111). The large size of its unit cell has thus far prevented the development of a definitive model for its structure. Using high-resolution scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we arrive at a model for the "29" CuxO film on Cu(111). There is very good agreement between experimental and computational STM images over a range of biases. Through the construction of a phase diagram from first-principles, we further find that the "29" structure derived from the DFT calculations is indeed the most stable structure under the experimental conditions considered. This work yields an accurate picture of the atomic scale structure of the "29" oxide film and therefore a basis for beginning to understand adsorption sites and reaction mechanisms on this catalytically relevant surface.
AB - Copper is a common catalyst for many important chemical reactions including low-temperature water gas shift, selective catalytic reduction of NOx, methanol synthesis, methanol steam reforming, and partial oxidation of methanol. The degree of surface oxidation, or the oxidation state of the active site, during these reactions has been debated and is known to have a large influence on the reaction rates. Therefore, elucidating the atomic-scale structure of copper surface oxides is an important step toward a fuller understanding of reaction mechanisms in heterogeneous catalysis. The so-called "29" monolayer oxide film is a common intermediate in the oxidation of Cu(111). The large size of its unit cell has thus far prevented the development of a definitive model for its structure. Using high-resolution scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we arrive at a model for the "29" CuxO film on Cu(111). There is very good agreement between experimental and computational STM images over a range of biases. Through the construction of a phase diagram from first-principles, we further find that the "29" structure derived from the DFT calculations is indeed the most stable structure under the experimental conditions considered. This work yields an accurate picture of the atomic scale structure of the "29" oxide film and therefore a basis for beginning to understand adsorption sites and reaction mechanisms on this catalytically relevant surface.
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U2 - 10.1021/acs.jpcc.6b01284
DO - 10.1021/acs.jpcc.6b01284
M3 - Article
AN - SCOPUS:84973097915
SN - 1932-7447
VL - 120
SP - 10879
EP - 10886
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 20
ER -