TY - JOUR
T1 - Orientation-Dependent Hindrance to the Oxidation of Pd-Au Alloy Surfaces
AU - Toyoshima, Ryo
AU - Amemiya, Kenta
AU - Mase, Kazuhiko
AU - Kondoh, Hiroshi
N1 - Funding Information:
We thank the staff of the Keio University Center Service Facilities for Research and the Photon Factory for their technical support. This study was supported by the Grants-in-Aid for scientific research (26248008) and Izumi Science and Technology Foundation (2019-J-076). The experiments were performed under the approval of the Photon Factory Program Advisory Committee (PF PAC 2018S2-005).
Publisher Copyright:
© XXXX American Chemical Society.
PY - 2020
Y1 - 2020
N2 - Oxidation of monometallic Pd and bimetallic Pd3Au alloy surfaces are observed by in situ ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) at an elevated pressure (100 mTorr O2 ambient). It is directly evidenced that the alloying with Au hinders the surface oxidation of Pd3Au surfaces compared with monometallic Pd surfaces. Remarkably, the oxidation behavior is clearly different between Pd3Au(111) and (100) surfaces. The (100) surface has a relatively Pd-rich surface composition, and the surface oxide layer is formed, whereas the (111) surface has a Au-rich composition, and the surface oxidation is quite limited. A combined approach of experimental and theoretical techniques reveals that Pd/Au surface composition and atomic arrangement are key factors determining the oxidation behavior.
AB - Oxidation of monometallic Pd and bimetallic Pd3Au alloy surfaces are observed by in situ ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) at an elevated pressure (100 mTorr O2 ambient). It is directly evidenced that the alloying with Au hinders the surface oxidation of Pd3Au surfaces compared with monometallic Pd surfaces. Remarkably, the oxidation behavior is clearly different between Pd3Au(111) and (100) surfaces. The (100) surface has a relatively Pd-rich surface composition, and the surface oxide layer is formed, whereas the (111) surface has a Au-rich composition, and the surface oxidation is quite limited. A combined approach of experimental and theoretical techniques reveals that Pd/Au surface composition and atomic arrangement are key factors determining the oxidation behavior.
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U2 - 10.1021/acs.jpclett.0c02645
DO - 10.1021/acs.jpclett.0c02645
M3 - Article
C2 - 33073999
AN - SCOPUS:85095799567
SP - 9249
EP - 9254
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
ER -