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XPS study of Al‐Alkyl effect on Ziegler–Natta catalytic system
Author(s) -
Wenqing Huang,
Xi Zhao,
Ying Zhang
Publication year - 2012
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3849
Subject(s) - x ray photoelectron spectroscopy , alkyl , catalysis , titanium , valence (chemistry) , chemistry , chemical state , aluminium , natta , inorganic chemistry , chemical engineering , organic chemistry , polymer , polymerization , engineering
X‐ray photoelectron spectroscopy was performed on Ziegler–Natta catalysts to elucidate the effect of aluminum alkyl compounds (Al‐Alkyl) on TiCl x /MgCl 2 /THF catalytic system. Chemical structure and element composition changes of catalysts were studied and various reduction activity of Al‐alkyl on catalysts was identified in different processes. The analytical results indicate that XPS is an acceptable method to measure titanium valence in Al‐alkyl‐ZN catalysts with a proper sample protection method. The XPS results demonstrate that the Al‐alkyl treatment of ZN catalysts could influence the chemical state of titanium dramatically. In Method A, the valence of Ti was reduced to Ti 3+ partially, and the contents of Ti 3+ increased with the increasing amount of DC, but Ti 2+ was absent. With same amount of Al%, combination of DC and THA has better reduction effect than DC with Method B. Copyright © 2011 John Wiley & Sons, Ltd.