| Popis: |
An X-ray photoelectron spectroscopic study of the reducibility of Ptγ-Al2O3, Geγ-Al2O3, and Pt, Geγ-Al2O3 systems has shown that: (i) treatment with H2 at temperatures up to 650 °C leads to interaction between Pt and Ge, giving rise to the formation of PtGe alloys; (ii) in the absence of platinum, germanium is difficult to reduce and at 650 °C seems to dissolve in the alumina matrix whereas in the presence of platinum, it remains in a exposed state. The results strongly suggest that in both Ptγ-Al2O3 and Pt, Geγ-Al2O3 “platinum atoms” are present in an electron-deficient state. |
