Electron spectroscopy of sulfated zirconia, its activity in n-hexane conversion and possible reasons of its deactivation

摘要

Sulfated zirconia catalyst were prepared and characterized by X-ray photoelectron spectroscopy taken in the dried state (fresh) and after calcination at 900 K (calc.)A maximum activity was observed as a function of the calcination temperature. The Zr 3d region showed that any Zr hydroxide in the dried catalyst transformed into zirconium oxide upon calcination. The O 1s peak could be fitted by two components corresponding to ZrO_2 and sulfate, respectively. Sulfur was present as sulfate. Both catalysts showed activity in n-hexane conversion (including isomerization) between 300 and 473 K. The activity of the calcined catalyst was much higher. The main products were isopentane and isobutane, along with 2-methyl-and 3-methylpentane.