UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts
- Univ. of California, Berkeley, CA (United States)
X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl4 and a Al(Et)3 co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl2 and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl4 in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl2 by TiCl4 resulting in a thin film of MgCl2/TiClx, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl2/TiClx on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to ~1 Torr of Al(Et)3.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 803863
- Report Number(s):
- LBNL-51336; R&D Project: 517101; B& R KC0203010; TRN: US200301%%551
- Resource Relation:
- Other Information: TH: Thesis (Ph.D.); Submitted to University of California, Berkeley, CA (US); PBD: 19 Aug 2002
- Country of Publication:
- United States
- Language:
- English
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