Au3Sr/MgO

Fig. 1.76. TPR spectra of CO2 formation on (a) an MgO(lOO) film, (b) Au3Sr/MgO(FC), (c) Au4/MgO(FC), (d) Aus/MgO(FC), and (e) a thick gold film grown on MgO(lOO). The Au4/MgO(FC), pure MgO film, and the thick Au film are catalytically inert. The inset compares the chemical reactivity R of pure Au and doped Au Sr clusters, with 1 < n < 9, expressed by the number of product CO2 molecules per deposited cluster. The TPR spectra are recorded after exposure of the model catalyst to isotopically labeled 02 and C 0 at 90K. Only the production of the isotopomer is detected by measuring its ion current...

Figure 9.7 Temperature-programmed reaction (TPR) spectra for CO oxidation at a series of model catalysts prepared by the soft landing of mass-selected Aun and AunSr cluster ions on MgO(lOO) thin films which are vacancy free (typically 1 % of a monolayer), (a) MgO (b) Au3Sr (c) Au4 (d) Au8. Also shown is the chemical reactivity R of pure Aun and AunSr clusters with 1 < n < 9. (Reproduced from Ref. 21).

Fig. 17.7. The optimized atomic structures of nanocatalysts comprised of Aus (a,b), Au4 (c), Au3Sr (d) clusters adsorbed at an F center of a MgO(IOO). For Aus two relevant isomers,...

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