TY - JOUR
T1 - PtxGd alloy formation on Pt(111): Preparation and structural characterization
AU - Ulrikkeholm, Elisabeth Therese
AU - Pedersen, Anders Filsøe
AU - Vej-Hansen, Ulrik Grønbjerg
AU - Escribano, Maria Escudero
AU - Stephens, Ifan
AU - Friebel, Daniel
AU - Mehta, Apurva
AU - Schiøtz, Jakob
AU - Feidenhansl', Robert K.
AU - Nilsson, Anders
AU - Chorkendorff, Ib
PY - 2016
Y1 - 2016
N2 - Pt x Gd single crystals have been prepared in ultra high vacuum (UHV). This alloy shows promising catalytic properties for the oxygen reduction reaction. The samples were prepared by using vacuum deposition of a thick layer of Gd on a sputter cleaned Pt(111) single crystal, resulting in a ∼63nm thick alloy layer. Subsequently the surfaces were characterized using X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), ion scattering spectroscopy (ISS) and temperature programmed desorption (TPD) of CO. A Pt terminated alloy was observed upon annealing the sample to 600 (ring operator)C. The LEED and synchrotron XRD experiments have shown that a slightly compressed (2 ×2) alloy appear. The alloy film followed the orientation of the Pt(111) substrate half the time, otherwise it was rotated by 30(ring operator). The TPD spectra show a well-defined peak shifted down 200 (ring operator)C in temperature. The crystal structure of the alloy was investigated using ex-situ X-ray diffraction experiments, which revealed an in-plane compression and a complicated stacking sequence. The crystallites in the crystal are very small, and a high degree of twinning by merohedry was observed.
AB - Pt x Gd single crystals have been prepared in ultra high vacuum (UHV). This alloy shows promising catalytic properties for the oxygen reduction reaction. The samples were prepared by using vacuum deposition of a thick layer of Gd on a sputter cleaned Pt(111) single crystal, resulting in a ∼63nm thick alloy layer. Subsequently the surfaces were characterized using X-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED), ion scattering spectroscopy (ISS) and temperature programmed desorption (TPD) of CO. A Pt terminated alloy was observed upon annealing the sample to 600 (ring operator)C. The LEED and synchrotron XRD experiments have shown that a slightly compressed (2 ×2) alloy appear. The alloy film followed the orientation of the Pt(111) substrate half the time, otherwise it was rotated by 30(ring operator). The TPD spectra show a well-defined peak shifted down 200 (ring operator)C in temperature. The crystal structure of the alloy was investigated using ex-situ X-ray diffraction experiments, which revealed an in-plane compression and a complicated stacking sequence. The crystallites in the crystal are very small, and a high degree of twinning by merohedry was observed.
KW - Alloy formation
KW - Platinum alloys
KW - Single crystals
KW - X-ray diffraction
U2 - 10.1016/j.susc.2016.02.009
DO - 10.1016/j.susc.2016.02.009
M3 - Journal article
VL - 652
SP - 114
EP - 122
JO - Surface Science
JF - Surface Science
SN - 0039-6028
ER -