XPS investigation of the electronic environment in selected heterogenized zirconocene catalysts

M. Atiqullah; M. Faiz; M. N. Akhtar; M. A. Salim; S. Ahmed; J. H. Khan

doi:10.1002/(sici)1096-9918(199908)27:8<728::aid-sia566>3.0.co;2-h

XPS investigation of the electronic environment in selected heterogenized zirconocene catalysts

M. Atiqullah^*, M. Faiz, M. N. Akhtar, M. A. Salim, S. Ahmed, J. H. Khan

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

Ethylbisindenyl zirconium dichloride (Et(Ind)₂ZrCl₂) and the MAO methylalumoxane (MAO) co-catalyst were heterogenized on Davision silica 955 partially dehydroxylated at 275°C, following the concept of equilibrium adsorption. The influence of MAO on the electronic environment resulting from the heterogenization was investigated using XPS. Heterogenization of Et(Ind)₂ZrCl₂ and MAO on the above silica generated two types of zirconocenium cations (Cation 1 and Cation 2), independent of the heterogenization methods. Based on the postulated surface chemistry, Cation 1 is presumed to be in the form of an ion-pair [SiO]^-[Et(Ind)₂ZrCl]⁺, whereas Cation 2 is presumed to be a trapped multi-coordinated crown complex of MAO. In the absence of MAO, only Cation 1 is formed. The present study provides some support for the postulated surface chemistry regarding heterogenization of Et(Ind)₂ZrCl₂ and MAO on silica.

Original language	English
Pages (from-to)	728-734
Number of pages	7
Journal	Surface and Interface Analysis
Volume	27
Issue number	8
DOIs	https://doi.org/10.1002/(sici)1096-9918(199908)27:8<728::aid-sia566>3.0.co;2-h
State	Published - 1999

ASJC Scopus subject areas

General Chemistry
Condensed Matter Physics
Surfaces and Interfaces
Surfaces, Coatings and Films
Materials Chemistry

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10.1002/(sici)1096-9918(199908)27:8<728::aid-sia566>3.0.co;2-h

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@article{12cce5449204490c9eea093211a3271e,

title = "XPS investigation of the electronic environment in selected heterogenized zirconocene catalysts",

abstract = "Ethylbisindenyl zirconium dichloride (Et(Ind)2ZrCl2) and the MAO methylalumoxane (MAO) co-catalyst were heterogenized on Davision silica 955 partially dehydroxylated at 275°C, following the concept of equilibrium adsorption. The influence of MAO on the electronic environment resulting from the heterogenization was investigated using XPS. Heterogenization of Et(Ind)2ZrCl2 and MAO on the above silica generated two types of zirconocenium cations (Cation 1 and Cation 2), independent of the heterogenization methods. Based on the postulated surface chemistry, Cation 1 is presumed to be in the form of an ion-pair [SiO]-[Et(Ind)2ZrCl]+, whereas Cation 2 is presumed to be a trapped multi-coordinated crown complex of MAO. In the absence of MAO, only Cation 1 is formed. The present study provides some support for the postulated surface chemistry regarding heterogenization of Et(Ind)2ZrCl2 and MAO on silica.",

author = "M. Atiqullah and M. Faiz and Akhtar, \{M. N.\} and Salim, \{M. A.\} and S. Ahmed and Khan, \{J. H.\}",

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language = "English",

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T1 - XPS investigation of the electronic environment in selected heterogenized zirconocene catalysts

AU - Atiqullah, M.

AU - Faiz, M.

AU - Akhtar, M. N.

AU - Salim, M. A.

AU - Ahmed, S.

AU - Khan, J. H.

PY - 1999

Y1 - 1999

N2 - Ethylbisindenyl zirconium dichloride (Et(Ind)2ZrCl2) and the MAO methylalumoxane (MAO) co-catalyst were heterogenized on Davision silica 955 partially dehydroxylated at 275°C, following the concept of equilibrium adsorption. The influence of MAO on the electronic environment resulting from the heterogenization was investigated using XPS. Heterogenization of Et(Ind)2ZrCl2 and MAO on the above silica generated two types of zirconocenium cations (Cation 1 and Cation 2), independent of the heterogenization methods. Based on the postulated surface chemistry, Cation 1 is presumed to be in the form of an ion-pair [SiO]-[Et(Ind)2ZrCl]+, whereas Cation 2 is presumed to be a trapped multi-coordinated crown complex of MAO. In the absence of MAO, only Cation 1 is formed. The present study provides some support for the postulated surface chemistry regarding heterogenization of Et(Ind)2ZrCl2 and MAO on silica.

AB - Ethylbisindenyl zirconium dichloride (Et(Ind)2ZrCl2) and the MAO methylalumoxane (MAO) co-catalyst were heterogenized on Davision silica 955 partially dehydroxylated at 275°C, following the concept of equilibrium adsorption. The influence of MAO on the electronic environment resulting from the heterogenization was investigated using XPS. Heterogenization of Et(Ind)2ZrCl2 and MAO on the above silica generated two types of zirconocenium cations (Cation 1 and Cation 2), independent of the heterogenization methods. Based on the postulated surface chemistry, Cation 1 is presumed to be in the form of an ion-pair [SiO]-[Et(Ind)2ZrCl]+, whereas Cation 2 is presumed to be a trapped multi-coordinated crown complex of MAO. In the absence of MAO, only Cation 1 is formed. The present study provides some support for the postulated surface chemistry regarding heterogenization of Et(Ind)2ZrCl2 and MAO on silica.

UR - https://www.scopus.com/pages/publications/0032659397

U2 - 10.1002/(sici)1096-9918(199908)27:8<728::aid-sia566>3.0.co;2-h

DO - 10.1002/(sici)1096-9918(199908)27:8<728::aid-sia566>3.0.co;2-h

M3 - Article

AN - SCOPUS:0032659397

SN - 0142-2421

VL - 27

SP - 728

EP - 734

JO - Surface and Interface Analysis

JF - Surface and Interface Analysis

IS - 8

ER -

XPS investigation of the electronic environment in selected heterogenized zirconocene catalysts

Abstract

ASJC Scopus subject areas

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