B. Shelimov et al., PLATINUM SPECIATION DURING SUPPORTED CATA LYSTS PREPARATION FOLLOWED BY PT-195 NMR, Bulletin de la Societe chimique de France, 133(6), 1996, pp. 617-623
Platinum speciation during supported catalysts preparation followed by
Pt-195 NMR. The initial steps of Pt/Al2O3 and Pt/SiO2 preparation fro
m hexachloroplatinate solutions were studied by both liquid-state and
solid-state Pt-195 NMR spectroscopy. These two techniques can provide
new information at three levels: (i) liquid-state Pt-195 NMR spectrosc
opy evidences changes in platinum speciation in solution upon contact
with the solid support; (ii) Pt-195 NMR allows direct observation of a
dsorbed species at the support/solution interface and the study of the
ir interaction with the support; and (iii) solid-state Pt-195 NMR spec
troscopy allows further reactions of the platinum species on drying an
d low-temperature thermal treatments to be followed, as long as the lo
cal symmetry remains quasi-octahedral. The information gained in this
way also leads to significant progress in the interpretation of other
experimental results, for example, the temperature-programmed reductio
n of Pt/SiO2.