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Abstract:
Based on spin-polarized density functional theory and generalized gradient approximation (DFT-GGA) calculations, the coverage-dependent adsorption of X bimetallic clusters (X=Pt-Au, Au-Au) on the (3 x 2) TiO2(110) surface has been investigated utilizing periodic supercell models in the absence of oxygen vacancy sites. Only the ground-state structures corresponding to the given coverage patterns (theta= 1/6-1 ML) for X clusters are discussed in this work. The unambiguous results reveal that the adsorption energies increase with coverage up to 1/2 ML and then decrease except for when saturated coverage is reached. According to the interaction with X clusters, it is more feasible at all coverage levels to create a monolayer film of Pt-Au bimetallic clusters on the TiO2(110) surface than it is to create a monolayer of Au-Au clusters, even though the adsorption energy of the Pt-Au/TiO2 adsorption system is smaller in comparison with that of the Au-Au/TiO2 system. Importantly, especially for the half and saturated coverages, there is a broadening of X peaks overlapping with the TiO2 state ranging from -3.0 eV to the Fermi level, suggesting a strong interaction between the surface and bimetallic cluster. Also of particular interest is the adsorptive mechanism where the X-TiO2 interaction is the main driving force at the initial stage of the adsorption process, whereas the X-X interaction controls the process as the coverage increases.
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ACTA PHYSICO-CHIMICA SINICA
ISSN: 1000-6818
CN: 11-1892/O6
Year: 2012
Issue: 8
Volume: 28
Page: 1861-1868
0 . 8 6 9
JCR@2012
1 0 . 8 0 0
JCR@2023
ESI Discipline: CHEMISTRY;
JCR Journal Grade:4
CAS Journal Grade:4
Cited Count:
WoS CC Cited Count: 1
SCOPUS Cited Count: 1
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 2
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