Title
|
|
|
|
Accessibility and dispersion of vanadyl sites of vanadium silicate-1 nanoparticles deposited in SBA-15
| |
Author
|
|
|
|
| |
Abstract
|
|
|
|
Vanadium silicalite-1 (VS-1) nanoparticles dispersed onto the mesoporous walls of SBA-15 silica have characteristics different from those of the full-grown VS-1. In particular, the vanadium-binding site differs extensively. Here, we monitor the local environment of VO2+ with different electron paramagnetic resonance (EPR) techniques to obtain information about the heterogeneity of the vanadyl sites, the effect of a calcination/reduction cycle, and the subsequent adsorption of 13CO2 and NH3 to the vanadyl sites for both full-grown VS-1 and VS1-SBA15. Furthermore, two-cycle CO2 and NH3 adsorption experiments were performed. While the latter showed no chemisorption of CO2 at 373 K for both materials, clear evidence was found for ligation of CO2 to vanadyl in full-grown VS-1 by the detection of a strong 13C hyperfine value. This strong binding was not detected for the vanadyl centers in VS1-SBA15. Chemisorption of NH3 was detected for all samples both by two-cycle adsorption experiments and by EPR. |
| |
Language
|
|
|
|
English
| |
Source (journal)
|
|
|
|
The journal of physical chemistry: C : nanomaterials and interfaces. - Washington, D.C., 2007, currens
| |
Publication
|
|
|
|
Washington, D.C.
:
2010
| |
ISSN
|
|
|
|
1932-7447
[print]
1932-7455
[online]
| |
Volume/pages
|
|
|
|
114
:30
(2010)
, p. 12966-12975
| |
ISI
|
|
|
|
000280360500019
| |
Full text (Publisher's DOI)
|
|
|
|
| |
|