Abstract
A series of NbOx/ZrO2 catalysts containing ≤ 2.67 wt % Nb (≈ 80% nominal surface coverage) was prepared by incipient wetness impregnation from niobium oxalate and oxalic acid solution. Isopropanol decomposition was used as test reaction to assay the acidity of the solids and to seek a correlation between acidity and catalytic performance. Lewis acidity was found for all systems, while significant Brönsted acidity was only developed for the Nb/Al2O3 catalysts. In the latter case, Brönsted acid sites were detected after a critical Nb loading. The decomposition of 2-propanol on NbOx/ZrO2 catalysts was directly related to the presence and abundance of Brönsted acid sites. By comparing the reported structure of Nb species with the observed isopropanol decomposition activity and the abundance of Brönsted acid sites, monomeric species did not exhibit Brönsted acidity and were essentially inactive. The catalytic activity was associated with polymeric Nb species.
Original language | English |
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Pages (from-to) | 15-19 |
Number of pages | 5 |
Journal | Catalysis Letters |
Volume | 89 |
Issue number | 1-2 |
DOIs | |
Publication status | Published - Jul 2003 |
Externally published | Yes |
Keywords
- 2,6-Dimethylpyridine adsorption
- Acidity
- FT-IR
- Isopropanol dehydration
- Niobia zirconia catalysts
- Niobium oxide
- Zirconia
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)