Origin of broad molecular weight distribution of polyethylene produced by Phillips-type silica-supported chromium catalyst

被引：22

作者：

Tonosaki, Kiwamu ^{[1
]}

Taniike, Toshiaki ^{[1
]}

Terano, Minoru ^{[1
]}

机构：

[1] Japan Adv Inst Sci & Technol, Sch Mat Sci, Nomi, Ishikawa 9231292, Japan

来源：

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL | 2011年 / 340卷 / 1-2期

关键词：

Phillips catalyst; Density functional theory; Molecular weight distribution; Polyethylene (PE); D(0)F(N) TRANSITION-METALS; ETHYLENE POLYMERIZATION; UNIFIED VIEW; SURFACE; STATE; TRIMERIZATION; SPECTROSCOPY; CR(VI); PSEUDOPOTENTIALS; MECHANISM;

D O I：

10.1016/j.molcata.2011.03.005

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The origin of the broad molecular weight distribution of polyethylene produced by Phillips-type silica-supported chromium (Cr/SiO2) catalysts was studied by density functional calculations using active site models with various coordination environments. Difference of the coordination environment of chromium showed remarkable variations for both of the insertion and the chain transfer energies, resulting in a broad range of molecular weight from 10(2) to 10(10) g/mol at 350K. The results clarified that the special catalytic property of Cr/SiO2 for broad molecular weight distribution is attributed to the heterogeneity of the coordination environment of the chromium species. (C) 2011 Elsevier B.V. All rights reserved.

引用

页码：33 / 38

页数：6

共 37 条

[1] Ajjou JAN, 1998, J AM CHEM SOC, V120, P415
[2] A kinetic study of ethylene and 1-hexene homo- and copolymerization catalyzed by a silica-supported Cr(IV) complex: Evidence for propagation by a migratory insertion mechanism
Ajjou, JAN
Scott, SL
[J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (37) : 8968 - 8976
[3] AB-INITIO ENERGY-ADJUSTED PSEUDOPOTENTIALS FOR ELEMENTS OF GROUPS 13-17
BERGNER, A
DOLG, M
KUCHLE, W
STOLL, H
PREUSS, H
[J]. MOLECULAR PHYSICS, 1993, 80 (06) : 1431 - 1441
[4] KINETICS OF CHAIN TRANSFER DURING ETHYLENE POLYMERIZATION WITH CHROMIUM-OXIDE SILICA CATALYST
BLOM, R
FOLLESTAD, A
NOEL, O
[J]. JOURNAL OF MOLECULAR CATALYSIS, 1994, 91 (02): : 237 - 249
[5] A detailed model of local structure and silanol hydrogen banding of silica gel surfaces
Chuang, IS
Maciel, GE
[J]. JOURNAL OF PHYSICAL CHEMISTRY B, 1997, 101 (16): : 3052 - 3064
[6] AN ALL-ELECTRON NUMERICAL-METHOD FOR SOLVING THE LOCAL DENSITY FUNCTIONAL FOR POLYATOMIC-MOLECULES
DELLEY, B
[J]. JOURNAL OF CHEMICAL PHYSICS, 1990, 92 (01) : 508 - 517
[7] Evidence for a chromasiloxane ring size effect in Phillips (Cr/SiO2) polymerization catalysts
Demmelmaier, Cori A.
White, Rosemary E.
van Bokhoven, Jeroen A.
Scott, Susannah L.
[J]. JOURNAL OF CATALYSIS, 2009, 262 (01) : 44 - 56
[8] ENERGY-ADJUSTED ABINITIO PSEUDOPOTENTIALS FOR THE 1ST-ROW TRANSITION-ELEMENTS
DOLG, M
WEDIG, U
STOLL, H
PREUSS, H
[J]. JOURNAL OF CHEMICAL PHYSICS, 1987, 86 (02) : 866 - 872
[9] Molecular-level insight into Cr/silica Phillips-type catalysts: polymerization-active mononuclear chromium sites
Espelid, O
Borve, KJ
[J]. JOURNAL OF CATALYSIS, 2002, 205 (02) : 366 - 374
[10] Theoretical models of ethylene polymerization over a mononuclear chromium(II)/silica site
Espelid, O
Borve, KJ
[J]. JOURNAL OF CATALYSIS, 2000, 195 (01) : 125 - 139

← 1 2 3 4 →