English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  UV/Vis/near-IR spectroscopic characteristics of H4-xCsxPVMo11O40 (x=0,2) catalyst under different temperatures and gas atmospheres

Melsheimer, J., Kröhnert, J., Ahmad, R., Klokishner, S., Jentoft, F. C., Mestl, G., et al. (2002). UV/Vis/near-IR spectroscopic characteristics of H4-xCsxPVMo11O40 (x=0,2) catalyst under different temperatures and gas atmospheres. Physical Chemistry Chemical Physics, 4(11), 2398-2408. doi:10.1039/B109293F.

Item is

Files

show Files
hide Files
:
proppub2111cd_fuer_pdfmitzitat.pdf (Any fulltext), 501KB
Name:
proppub2111cd_fuer_pdfmitzitat.pdf
Description:
-
Visibility:
Public
MIME-Type / Checksum:
application/pdf / [MD5]
Technical Metadata:
Copyright Date:
-
Copyright Info:
-
License:
-

Locators

show

Creators

show
hide
 Creators:
Melsheimer, Jörg1, Author              
Kröhnert, Jutta1, Author              
Ahmad, Rafat1, Author              
Klokishner, Sophia, Author
Jentoft, Friederike C.1, Author              
Mestl, Gerhard1, Author              
Schlögl, Robert1, Author              
Affiliations:
1Inorganic Chemistry, Fritz Haber Institute, Max Planck Society, ou_24023              

Content

show
hide
Free keywords: SELECTIVE OXIDATION, HETEROPOLY COMPOUNDS, THERMAL-STABILITY, ISOBUTYRIC ACID, UV-VIS, CATALYSTS, MODEL, VANADIUM, METHANOL, GENESIS Project 5, Acid-base & redox properties of heteropoly compounds
 Abstract: In order to understand the transformations of the Keggin-type H4-xCsxPVMo11 (x=0,2) compounds with rising temperature over long time stream of different gas athmospheres, in situ UV/Vis/near-IR spectroscopic studies were carried out. Diffuse reflectance spectra were recorded using an improved spectrometer and a suitable microreactor. Visible and near-IR peak intensities, peak positions and the band gap energies were determined from apparent absorption spectra. Propene, iso-propanol, water and the oxidation products were analyzed by GC. The experimental observed blue shift of the visible absorption band in the range of crystal water loss and the increase of the near-IR absorption were explained on the basis of quantum-mechanical calculations of the shapes and positions of the charge transfer and d-d bands arising from Mo5+-Mo6+ and V4+-Mo6+ pairs in intact and ill-defined fragments of the Keggin structure. It was concluded that with removal of crystal water during the action of He, He/H2O, propene, O2/propene and increasing temperature reduced species with protons located at the bridging oxygens promote a blue shift of the visible band, while a large number of ill-defined species form the near-IR part of the spectra in the temperature range 326 - 600 K.

Details

show
hide
Language(s): eng - English
 Dates: 2002-04-29
 Publication Status: Published in print
 Pages: -
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: eDoc: 1558
DOI: 10.1039/B109293F
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Physical Chemistry Chemical Physics
  Alternative Title : Phys. Chem. Chem. Phys.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: -
Pages: - Volume / Issue: 4 (11) Sequence Number: - Start / End Page: 2398 - 2408 Identifier: ISSN: 1463-9076