Abstract
The surface of supported tungstophosphoric acid H3PW 12O40 (HPW) on all-silica MCM-41 has been investigated using high-resolution X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). The results show the interaction between HPW and MCM-41 upon impregnation. Nuclear magnetic resonance (NMR) spectroscopy results also seem to confirm the above conclusion. Heating the supported acid increased the structural damage of HPW and MCM-41. Our results also suggest the formation of tungsten oxides on the surface upon heat treatment at 400°C. A detailed analysis of the infrared (IR) spectra showed a gradual increase in the absorbance of the W-O-W corner shared vibration relative to the absorbance of the other bands. This indicates that the symmetry, and hence the stability of the bulk molecules were also decreased upon heating.
| Original language | English |
|---|---|
| Pages (from-to) | 1-6 |
| Number of pages | 6 |
| Journal | Applied Catalysis A: General |
| Volume | 257 |
| Issue number | 1 |
| DOIs | |
| State | Published - 10 Jan 2004 |
Bibliographical note
Funding Information:This work was partially supported by the US Department of Energy under contract number DE-AC03-76F00098. Jalil, Tabet and Faiz would like to thank KFUPM for its support.
Keywords
- HPWO
- IR
- MCM-41
- Tungstophosphoric acid
- XANES
- XPS
ASJC Scopus subject areas
- Catalysis
- Process Chemistry and Technology