ISSN:
1572-9028
Keywords:
ZrO2–TiO2 and ZrO2–SiO2
;
pure and sulfated, acidity of
;
isomerization
;
of cyclopropane
;
of n‐hexane
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Protonated pyridine (PyH+) was not found on ZrO2 (Z) or ZrO2–TiO2 (ZT), but was detected on sulfated oxides (Z‐S, ZT‐S) by IR spectroscopy. In contrast, ZrO2–SiO2 samples containing about 30–80 mol% ZrO2 showed Brønsted acidity both in non‐sulfated (ZS) and sulfated (ZS‐S) forms. The total acidity was determined by NH3‐TPD. Introduction of sulfate ions increased the site‐specific catalytic activity (TOF) in the conversion of cyclopropane or n‐hexane. The effect of sulfate ions was more significant on samples rich in zirconia. Results suggest that Zr is homogeneously distributed in ZS samples rich in silica. Zirconia‐bound dimeric sulfate, generating strong acidity, could not be formed in these preparations due to the absence of fairly large ZrO2 domains.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019112017065
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