About the importance of surface hydrogen availability during n-hexane isomerizatrion over platinum oxide promoted zirconia

M.G. FALCO; S.A. CANAVESE; R.A. COMELLI; N.S. FÍGOLI

STUDIES IN SURFACE SCIENCE AND CATALYSIS

Elsevier

Año: 2000 p. 2393 - 2398

0167-2991

The influence of the platinum precursor (hexachloroplatinic acid or tetraamminplatinum nitrate) and concentration and of the calcination temperarure after platinum addition on tungsten oxide promoted zirconia during n-hexane isomerization was studied. A mechanical mixture of Pt/SiO2 and tungsten oxide promoted zirconia was also used as catalyst. The catalytic activity, selectivity and stability are related to the hydrogen availability at the surface, that is measure as a function of the methylcyclopentane to n-hexane isomers ratio. The hydrogen availability depends on a minimum concentration of platinum (above 0.05%); it is independent of the platinum precursor used in catalyst preparation and almost independent of the temperature of activation (in the 450-600 ºC range) after platinum addition in the 450-600 ºC range.