کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1615579 | 1516350 | 2012 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Structural, electronic and adsorption properties of V–Rh(111) subsurface alloy Structural, electronic and adsorption properties of V–Rh(111) subsurface alloy](/preview/png/1615579.png)
V–Rh(111) bimetallic systems were prepared by deposition of 0.4 and 2.5 ML of vanadium on Rh(111) surface at 823 K and by annealing up to 1023 K. Subsurface alloys of similar composition and electronic structure were formed. On the latter one, (2 × 2) surface reconstruction was observed. Electronic structure of the V–Rh(111) subsurface alloys was studied by photoelectron spectroscopy utilizing synchrotron radiation. Atomic structure was studied by means of LEED and X-ray photoelectron diffraction. Chemisorption properties were probed by CO and O2 adsorption. The topmost atomic layer with (2 × 2) reconstruction consisted exclusively of Rh atoms. The obtained results indicate formation of alloy with Rh3V composition and L12-type structure. Changes observed in the electronic structure were correlated with lower reactivity towards CO adsorption. The photoemission data indicate that the CO saturation coverage at 300 K is reduced to less than half on the alloy surface as compared to clean Rh(111). Oxygen adsorbed on the alloy surface strongly interacted with the subsurface vanadium and induced formation of a surface vanadium oxide.
► V–Rh(111) subsurface alloy with (2 × 2) surface reconstruction was prepared.
► Substitutional alloy with Rh3V composition and L12 structure was formed.
► Decreased density of states at the Fermi edge was observed upon alloying.
► Electronic changes were correlated with lower reactivity towards CO adsorption.
► Oxygen adsorbed on the surface reacted with the subsurface vanadium.
Journal: Journal of Alloys and Compounds - Volume 543, 5 December 2012, Pages 189–196