Operando Molecular Spectroscopy During Ethylene Polymerization by Supported CrOx/SiO2 Catalysts: Active Sites, Reaction Intermediates, and Structure-Activity Relationship

被引：49

作者：

Chakrabarti, Anisha ^{[1
]}

Gierada, Maciej ^{[2
]}

Handzlik, Jaroslaw ^{[2
]}

Wachs, Israel E. ^{[1
]}

机构：

[1] Lehigh Univ, Dept Chem & Biomol Engn, Operando Mol Spect & Catalysis Lab, Bethlehem, PA 18015 USA

[2] Cracow Univ Technol, Fac Chem Engn & Technol, Ul Warszawska 24, PL-31155 Krakow, Poland

来源：

TOPICS IN CATALYSIS | 2016年 / 59卷 / 8-9期

关键词：

Polymerization; Ethylene; Cr; Spectroscopy; Operando; DFT; PHILLIPS CR/SILICA CATALYSTS; DENSITY-FUNCTIONAL METHODS; IN-SITU; PROTON TRANSFERS; SILICA CATALYST; LEVEL INSIGHT; CHROMIUM; ACTIVATION; INITIATION; CHEMISTRY;

D O I：

10.1007/s11244-016-0546-6

中图分类号：

O69 [应用化学];

学科分类号：

081704 ;

摘要：

Time-resolved operando molecular spectroscopy was applied during ethylene polymerization by supported CrOx/SiO2 catalysts to investigate the structure-activity relationships for this important industrial catalytic reaction. A combination of spectroscopic techniques (Raman, UV-Vis, XAS, DRIFTS and TPSR) during ethylene polymerization allows for the first time to monitor the molecular events taking place during activation of supported CrOx/SiO2 catalysts by ethylene and establishment of the structure-activity relationships for this reaction. Based on complementary DFT computational studies, a new initiation mechanism for ethylene polymerization is proposed. During reaction, the initial surface Cr+6Ox sites reduce to Cr+3 sites to form Cr-(CH2)(2)CH=CH2 and Cr-CH=CH2 reaction intermediates with the latter representing the catalytic active site.

引用

页码：725 / 739

页数：15

共 63 条

[1] Toward reliable density functional methods without adjustable parameters: The PBE0 model [J].

Adamo, C ;

Barone, V .

JOURNAL OF CHEMICAL PHYSICS, 1999, 110 (13) :6158-6170

[2] Gabedit-A Graphical User Interface for Computational Chemistry Softwares [J].

Allouche, Abdul-Rahman .

JOURNAL OF COMPUTATIONAL CHEMISTRY, 2011, 32 (01) :174-182

[3]

[Anonymous], 2011, NIST CHEM WEBBOOK

[4] OXIDATION OF OLEFINS BY SUPPORTED CHROMIUM OXIDE [J].

BAKER, LM ;

CARRICK, WL .

JOURNAL OF ORGANIC CHEMISTRY, 1968, 33 (02) :616-&

[5] Ethylene polymerization on a SiH4-modified Phillips catalyst: detection of in situ produced α-olefins by operando FT-IR spectroscopy [J].

Barzan, Caterina ;

Groppo, Elena ;

Quadrelli, Elsje Alessandra ;

Monteil, Vincent ;

Bordiga, Silvia .

PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2012, 14 (07) :2239-2245

[6] On the first stages of the ethylene polymerization on Cr2+/SiO2 Phillips catalyst:: time and temperature resolved IR studies [J].

Bordiga, S ;

Bertarione, S ;

Damin, A ;

Prestipino, C ;

Spoto, G ;

Lamberti, C ;

Zecchina, A .

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL, 2003, 204 :527-534

[7] Mechanism of Initiation in the Phillips Ethylene Polymerization Catalyst: Redox Processes Leading to the Active Site [J].

Brown, Carole ;

Krzystek, J. ;

Achey, Randall ;

Lita, Adrian ;

Fu, Riqang ;

Meulenberg, Robert W. ;

Polinski, Matthew ;

Peek, Nathan ;

Wang, Youhong ;

de Burgt, Lambertus J. van ;

Profeta, Salvatore, Jr. ;

Stiegman, A. E. ;

Scott, Susannah L. .

ACS CATALYSIS, 2015, 5 (09) :5574-5583

[8] The Nature of Surface CrOx Sites on SiO2 in Different Environments [J].

Chakrabarti, Anisha ;

Wachs, Israel E. .

CATALYSIS LETTERS, 2015, 145 (04) :985-994

[9] Corrigendum: Polymerization of Ethylene by Silica-Supported Dinuclear CrIII Sites through an Initiation Step Involving CH Bond Activation (vol 53, pg 1872, 2014) [J].

Conley, Matthew P. ;

Delley, Murielle F. ;

Siddiqi, Georges ;

Lapadula, Giuseppe ;

Norsic, Sebastien ;

Monteil, Vincent ;

Safonova, Olga V. ;

Coperet, Christophe .

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2015, 54 (23) :6670-6670

[10] Heterolytic Activation of C-H Bonds on CrIII-O Surface Sites Is a Key Step in Catalytic Polymerization of Ethylene and Dehydrogenation of Propane [J].

Conley, Matthew P. ;

Delley, Murielle F. ;

Nunez-Zarur, Francisco ;

Comas-Vives, Aleix ;

Coperet, Christophe .

INORGANIC CHEMISTRY, 2015, 54 (11) :5065-5078

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