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 27 条

[21] The structure-reactivity relationship for metathesis reaction between ethylene and 2-butene on WO3/SiO2 catalysts calcinated at different temperatures
Chaemchuen, S.
Phatanasri, S.
Verpoort, F.
Sae-ma, N.
Suriye, K.
KINETICS AND CATALYSIS, 2012, 53 (02) : 247 - 252
[22] Structure-Activity Relationships in the Ammoxidation of Ethylene in the Absence of Molecular Oxygen over gamma-Al2O3-Supported Molybdenum Oxide Catalysts
J Catal, 1 (28):
[23] Molecular structure and catalytic promotional effect of Mn on supported Na2WO4/SiO2 catalysts for oxidative coupling of methane (OCM) reaction
Sourav, Sagar
Kiani, Daniyal
Wang, Yixiao
Baltrusaitis, Jonas
Fushimi, Rebecca R.
Wachs, Israel E.
CATALYSIS TODAY, 2023, 416
[24] Cu/SiO2 and Cu/SiO2-TiO2 catalysts II.: Identification of the active sites during polymerisation of 2,6-dimethylphenol in the presence of molecular O2
Boccuzzi, F
Martra, G
Papalia, CP
Ravasio, N
JOURNAL OF CATALYSIS, 1999, 184 (02) : 327 - 334
[25] In Situ Spectroscopic Insights on the Molecular Structure of the MgO/SiO2 Catalytic Active Sites during Ethanol Conversion to 1,3-Butadiene
Taifan, William E.
Baltrusaitis, Jonas
JOURNAL OF PHYSICAL CHEMISTRY C, 2018, 122 (36): : 20894 - 20906
[26] Energy-saving CO2 desorption from amine solution over Fe/SiO2/biochar catalysts: Desorption performance, structure-activity relationship, and mechanism
Rao, Li
Jin, Bangheng
Chen, Dong
Jin, Xin
Liu, Guangrong
Huang, Zilin
Cao, Kaihong
Chen, Fangyue
Huang, Qiang
CHEMICAL ENGINEERING JOURNAL, 2024, 483
[27] Site-selective X-ray absorption fine structure (XAFS) spectroscopy (2).: XAFS spectra tuned to surface active sites of Cu/ZnO and Cr/SiO2 catalysts
Izumi, Y
Nagamori, N
BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 2000, 73 (07) : 1581 - 1587

← 1 2 3 →