The adsorption of AuxTiy (x + y = 4, 5) bimetallic clusters on the hydroxyl-free and fully hydroxylated α-quartz (001) surfaces was investigated via density functional theory calculations including van der Waals (vdW) forces. The pure gold clusters adsorb only weakly on the silica surfaces via vdW forces. The interaction with the silica surfaces changes dramatically when Au atoms of the clusters are replaced by Ti. For y ≥ 2, the clusters react with the surface via oxygen spillover (on the hydroxyl-free surface) and hydrogen spillover (on the hydroxylated surface). These bimetallic clusters with more than one Ti atom exhibit very large adsorption energies in the range of -3 to -9 eV. The substitution of only one Au atom by Ti (y = 1) results in an intermediate effect on the adsorption strength. It may, however, be sufficient for the in situ formation of gas-phase hydrogen via reaction of the clusters with surface hydroxyl groups, resulting in strongly bound ≡Si-O-AuxTiy complexes.

Schlexer, P., Pacchioni, G. (2017). Anchoring Small Au Clusters on the Dehydroxylated and Hydroxylated SiO2 α-Quartz (001) Surface via Ti-Alloying. JOURNAL OF PHYSICAL CHEMISTRY. C, 121(27), 14717-14724 [10.1021/acs.jpcc.7b04420].

Anchoring Small Au Clusters on the Dehydroxylated and Hydroxylated SiO2 α-Quartz (001) Surface via Ti-Alloying

Schlexer, P
;
Pacchioni, G
2017

Abstract

The adsorption of AuxTiy (x + y = 4, 5) bimetallic clusters on the hydroxyl-free and fully hydroxylated α-quartz (001) surfaces was investigated via density functional theory calculations including van der Waals (vdW) forces. The pure gold clusters adsorb only weakly on the silica surfaces via vdW forces. The interaction with the silica surfaces changes dramatically when Au atoms of the clusters are replaced by Ti. For y ≥ 2, the clusters react with the surface via oxygen spillover (on the hydroxyl-free surface) and hydrogen spillover (on the hydroxylated surface). These bimetallic clusters with more than one Ti atom exhibit very large adsorption energies in the range of -3 to -9 eV. The substitution of only one Au atom by Ti (y = 1) results in an intermediate effect on the adsorption strength. It may, however, be sufficient for the in situ formation of gas-phase hydrogen via reaction of the clusters with surface hydroxyl groups, resulting in strongly bound ≡Si-O-AuxTiy complexes.
Articolo in rivista - Articolo scientifico
Electronic, Optical and Magnetic Materials; Energy (all); Physical and Theoretical Chemistry; Surfaces, Coatings and Films
English
2017
121
27
14717
14724
open
Schlexer, P., Pacchioni, G. (2017). Anchoring Small Au Clusters on the Dehydroxylated and Hydroxylated SiO2 α-Quartz (001) Surface via Ti-Alloying. JOURNAL OF PHYSICAL CHEMISTRY. C, 121(27), 14717-14724 [10.1021/acs.jpcc.7b04420].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/183943
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