Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO<sub><italic style="font-style: italic">x</italic></sub>/SiO<sub>2</sub> UHMWPE Catalysts

Yu-Long Jin; Lin Liu; Yu-Jie Wang; Zhen Liu; Bo-Ping Liu

doi:10.1007/s10118-019-2295-z

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Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts

ARTICLE | Updated：2021-02-18

- Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts
- Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts
- Chinese Journal of Polymer Science 2019年37卷第10期页码：995-1004
- Affiliations：
  
  a.College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China
  b.School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
- Author bio：
  
  boping@scau.edu.cn
- Funds：
  
  This work was financially supported by the National Natural Science Foundation of China (No. 21801079).
- DOI：10.1007/s10118-019-2295-z
  中图分类号：
- 收稿：2019-03-30，
  
  修回：2019-5-13，
  
  录用：2019-5-16，
  
  网络首发：2019-07-02，
  
  纸质出版：2019-10
- Accepted：
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Citation: Jin, Y. L.; Liu, L.; Wang, Y. J.; Liu, Z.; Liu, B. P. Mechanistic study on the dominant promotion effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE catalysts. Chinese J. Polym. Sci. 2019, 37, 995–1004 DOI: 10.1007/s10118-019-2295-z.

Yu-Long Jin, Lin Liu, Yu-Jie Wang, et al. Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts[J]. Chinese Journal of Polymer Science, 2019, 37(10): 995-1004. DOI: 10.1007/s10118-019-2295-z.
Citation: Jin, Y. L.; Liu, L.; Wang, Y. J.; Liu, Z.; Liu, B. P. Mechanistic study on the dominant promotion effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE catalysts. Chinese J. Polym. Sci. 2019, 37, 995–1004 DOI: 10.1007/s10118-019-2295-z. DOI：

Yu-Long Jin, Lin Liu, Yu-Jie Wang, et al. Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts[J]. Chinese Journal of Polymer Science, 2019, 37(10): 995-1004. DOI: 10.1007/s10118-019-2295-z. DOI：

摘要

Abstract

Recently

we reported the first VO

/SiO

ethylene polymerization catalyst for making Cl-free UHMWPE

and found the dominant promotion effects of Al-/Ti-/Zr-modifications over this catalyst system (Macromol. Chem. Phys. 2017

218

1600443). In this work

density functional theory is applied to investigate the underlying mechanism of this remarkable promotion effect of Al-/Ti-/Zr-modifications on a molecular and atomic level. The cluster model with V(III) is found to be the most possible active site due to its lowest overall energy barrier for monomer insertion

though the process of C

coordination and the subsequent formation of transition state are most energy favored for V(II) species. By modifying one of or both V―O―Si in the active model with V―O―M (M ＝ Al

or Zr)

the energy barrier for the binding of the upcoming C

gets lower (particularly for Al- and Zr-modified catalysts)

and the transition state also becomes more stable. Generally

the insertion process of C

gets easier after support Al-/Ti-/Zr-modifications. This dominant promotion effect is partially ascribed to the more enriched positive charge distribution on or nearby the V center

and the narrower energy gap between the LUMO of model catalysts and the HOMO of C

for these modified catalysts also contributes much. In addition

the decreased steric hindrance around the V center should be taken into account for the modified models as well. Furthermore

the Brønsted acidity of the catalysts is investigated by introducing a pendent hydroxyl group to the model catalysts

which has a close contact with the V center. Similar promotion effect of support modification by Al

and Zr could still be observed.

关键词

Keywords

references

Weckhuysen, B. M.; Keller, D. E . Chemistry, spectroscopy and the role of supported vanadium oxides in heterogeneous catalysis . Catal. Today , 2003 . 78 25 - 46 . DOI: 10.1016/S0920-5861(02)00323-1 http://doi.org/10.1016/S0920-5861(02)00323-1 .

Matta, A.; Zeng, Y.; Taniike, T.; Terano, M . Vanadium-modified bimetallic phillips catalyst with high branching ability for ethylene polymerization . Macromol. Reac. Eng. , 2012 . 6 346 - 350 . DOI: 10.1002/mren.v6.8 http://doi.org/10.1002/mren.v6.8 .

Zeng, Y.; Matta, A.; Dwivedi, S.; Taniike, T.; Terano, M . Development of a hetero-bimetallic Phillips-type catalyst for ethylene polymerization . Macromol. Reac. Eng. , 2013 . 7 668 - 673 . DOI: 10.1002/mren.v7.12 http://doi.org/10.1002/mren.v7.12 .

Wang, J.; Cheng, R.; He, X.; Liu, Z.; Zhao, N.; Liu, B . Vanadium modification effects on the (SiO 2 /MgO/MgCl 2 )·TiCl x Ziegler-Natta polyethylene catalyst . Macromol. Reac. Eng. , 2016 . 10 246 - 260 . DOI: 10.1002/mren.201500056 http://doi.org/10.1002/mren.201500056 .

Cheng, R.; Xue, X.; Liu, W.; Zhao, N.; He, X.; Liu, Z.; Liu, B . Novel SiO 2 -supported chromium oxide (Cr)/vanadium oxide (V) bimetallic catalysts for production of bimodal polyethylene . Macromol. Reac. Eng. , 2015 . 9 462 - 472 . DOI: 10.1002/mren.v9.5 http://doi.org/10.1002/mren.v9.5 .

Zhao, N.; Cheng, R.; He, X.; Liu, Z.; Liu, B . A novel SiO 2 -supported Cr―V bimetallic catalyst making polyethylene and ethylene/1-hexene copolymers with bimodal molecular weight distribution . Macromol. Chem. Phys. , 2014 . 1753 - 1766 . .

Liu, B.; Tian, Z.; Zhao, N.; Liu, Z.; Liu, B . Peculiarities of ethylene polymerization kinetics with an imido-vanadium/silyl-chromate bimetallic catalyst: Effect of polymerization conditions . Ind. Eng. Chem. Res. , 2017 . 56 6164 - 6175 . DOI: 10.1021/acs.iecr.7b00883 http://doi.org/10.1021/acs.iecr.7b00883 .

Liu, B.; Zhao, N.; Jin, Y.; Cheng, R.; He, X.; Liu, Z.; Liu, B . Effects of alkyl aluminum on SiO 2 -supported silyl-chromate(Cr)/imido-vanadium(V) bimetallic catalysts for producing bimodal polyethylene . Macromol. Reac. Eng. , 2017 . 11 1700006 DOI: 10.1002/mren.v11.5 http://doi.org/10.1002/mren.v11.5 .

Jin, Y.; Zhao, N.; Cheng, R.; He, X.; Liu, Z.; Dong, D.; Bin, Y.; Chen, X.; Li, L.; Liu, B . One pot synthesis of bimodal UHMWPE/HDPE in-reactor blends with Cr/V bimetallic catalysts . J. Polym. Sci., Part A: Polym. Chem. , 2017 . 55 3404 - 3412 . DOI: 10.1002/pola.v55.20 http://doi.org/10.1002/pola.v55.20 .

Jin, Y.; Cheng, R.; He, X.; Liu, Z.; Zhao, N.; Liu, B . The first vanadium-oxide-based UHMWPE catalyst supported on chemically modified silica gel . Macromol. Chem. Phys. , 2017 . 218 1600443 DOI: 10.1002/macp.v218.7 http://doi.org/10.1002/macp.v218.7 .

McDaniel, M. P . A review of the Phillips supported chromium catalyst and its commercial use for ethylene polymerization . Adv. Catal. , 2010 . 53 123 - 606 . .

Gierada, M.; Handzlik, J . Active sites formation and their transformations during ethylene polymerization by the Phillips CrO x /SiO 2 catalyst . J. Catal. , 2017 . 352 314 - 328 . DOI: 10.1016/j.jcat.2017.05.025 http://doi.org/10.1016/j.jcat.2017.05.025 .

Anthony, G.; Alexis, T. B . A theoretical investigation of the selective oxidation of methanol to formaldehyde on isolated vanadate species supported on silica . J. Phys. Chem. C , 2008 . 112 13204 - 13214 . DOI: 10.1021/jp801339q http://doi.org/10.1021/jp801339q .

William, C. V.; Anthony, G.; Jennifer, S.; Alexis, T. B . An experimental and theoretical investigation of the structure and reactivity of bilayered VO x /TiO x /SiO 2 catalysts for methanol oxidation . J. Catal. , 2010 . 270 163 - 171 . DOI: 10.1016/j.jcat.2009.12.017 http://doi.org/10.1016/j.jcat.2009.12.017 .

Cheng, R.; Xu, C.; Liu, Z.; Dong, Q.; He, X.; Fang, Y.; Terano, M.; Hu, Y.; Pullukat, T. J.; Liu, B . High-resolution spectroscopy (XPS, 1H MAS solid-state NMR) and DFT investigations into Ti-modified Phillips CrO x /SiO 2 catalysts . J. Catal. , 2010 . 273 103 - 115 . DOI: 10.1016/j.jcat.2010.05.002 http://doi.org/10.1016/j.jcat.2010.05.002 .

Ma, Y.; Wang, L.; Liu, Z.; Cheng, R.; Zhong, L.; Yang, Y.; He, X.; Fang, Y.; Terano, M.; Liu, B . High-resolution XPS and DFT investigations into Al-modified Phillips CrO x /SiO 2 catalysts . J. Mol. Catal. A-Chem. , 2015 . 401 1 - 12 . DOI: 10.1016/j.molcata.2015.01.020 http://doi.org/10.1016/j.molcata.2015.01.020 .

Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Scalmani, G.; Barone, V.; Petersson, G. A.; Nakatsuji, H.; Li, X.; Caricato, M.; Marenich, A.; Bloino, J.; Janesko, B. G.; Gomperts, R.; Mennucci, B.; Hratchian, H. P.; Ortiz, J. V.; Izmaylov, A. F.; Sonnenberg, J. L.; Williams-Young, D.; Ding, F.; Lipparini, F.; Egidi, F.; Goings, J.; Peng, B.; Petrone, A.; Henderson, T.; Ranasinghe, D.; Zakrzewski, V. G.; Gao, J.; Rega, N.; Zheng, G.; Liang, W.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Vreven, T.; Throssell, K.; Montgomery, J. A.; Peralta, J. E.; Ogliaro, F.; Bearpark, M.; Heyd, J. J.; Brothers, E.; Kudin, K. N.; Staroverov, V. N.; Keith, T.; Kobayashi, R.; Normand, J.; Raghavachari, K.; Rendell, A.; Burant, J. C.; Iyengar, S. S.; Tomasi, J.; Cossi, M.; Millam, J. M.; Klene, M.; Adamo, C.; Cammi, R.; Ochterski, J. W.; Martin, R. L.; Morokuma, K.; Farkas, O.; Foresman, J. B.; Fox, D. J. in Gaussian 09, Revision E.01, Gaussian, Inc., Wallingford, CT, USA. 2016 .

Chai, J. D.; Head-Gordon, M . Long-range corrected hybrid density functionals with damped atom-atom dispersion corrections . Phys. Chem. Chem. Phys. , 2008 . 10 6615 - 6620 . DOI: 10.1039/b810189b http://doi.org/10.1039/b810189b .

Fong, A.; Ye, Y.; Ivry, S. L.; Scott, S. L.; Peters, B . Computational kinetic discrimination of ethylene polymerization mechanisms for the Phillips (Cr/SiO 2 ) catalyst . ACS Catal. , 2015 . 5 9882 - 9891 . .

Weigend, F.; Ahlrichs, R . Balanced basis sets of split valence, triple zeta valence and quadruple zeta valence quality for H to Rn: Design and assessment of accuracy . Phys. Chem. Chem. Phys. , 2005 . 7 3297 - 3305 . DOI: 10.1039/b508541a http://doi.org/10.1039/b508541a .

Gonzalez, C.; Schlegel, H. B . Reaction path following in mass-weighted internal coordinates . J. Phys. Chem. , 1990 . 94 5523 - 5527 . DOI: 10.1021/j100377a021 http://doi.org/10.1021/j100377a021 .

Maeda, S.; Harabuchi, Y.; Ono, Y.; Taketsugu, T.; Morokuma, K . Intrinsic reaction coordinate: Calculation, bifurcation, and automated search . Int. J. Quantum. Chem. , 2015 . 115 258 - 269 . DOI: 10.1002/qua.24757 http://doi.org/10.1002/qua.24757 .

Reed, A. E.; Weinhold, F.; Curtiss, L. A.; Pochatko, D. J . Natural bond orbital analysis of molecular interactions: Theoretical studies of binary complexes of HF, H 2 O, NH 3 , O 2 , F 2 , CO, and CO 2 with HF, H 2 O, and NH 3 . J. Chem. Phys. , 1986 . 84 5687 - 5705 . DOI: 10.1063/1.449928 http://doi.org/10.1063/1.449928 .

Frank, W . Natural bond orbital analysis: A critical overview of relationships to alternative bonding perspectives . J. Comput. Chem. , 2012 . 33 2363 - 2379 . DOI: 10.1002/jcc.v33.30 http://doi.org/10.1002/jcc.v33.30 .

Lu, T.; Chen, F . Multiwfn: A multifunctional wavefunction analyzer . J. Comput. Chem. , 2012 . 33 580 - 592 . DOI: 10.1002/jcc.v33.5 http://doi.org/10.1002/jcc.v33.5 .

Bader, R. F. W.; Carroll, M. T.; Cheeseman, J. R.; Chang, C . Properties of atoms in molecules: Atomic volumes . J. Am. Chem. Soc. , 1987 . 109 417 - 423 . DOI: 10.1021/ja00236a020 http://doi.org/10.1021/ja00236a020 .

Keller, D. E.; Visser, T.; Soulimani, F.; Koningsberger, D. C.; Weckhuysen, B. M . Hydration effects on the molecular structure of silica-supported vanadium oxide catalysts: A combined IR, Raman, UV-vis and EXAFS study . Vib. Spectrosc. , 2007 . 43 140 - 151 . DOI: 10.1016/j.vibspec.2006.07.005 http://doi.org/10.1016/j.vibspec.2006.07.005 .

Olthof, B.; Khodakov, A.; Bell, A. T.; Iglesia, E . Effects of support composition and pretreatment conditions on the structure of vanadia dispersed on SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , and HfO 2 . J. Phys. Chem. B , 2000 . 104 1516 - 1528 . DOI: 10.1021/jp9921248 http://doi.org/10.1021/jp9921248 .

Tian, H.; Ross, E. I.; Wachs, I. E . Quantitative determination of the speciation of surface vanadium oxides and their catalytic activity . J. Phys. Chem. B , 2006 . 110 9593 - 9600 . DOI: 10.1021/jp055767y http://doi.org/10.1021/jp055767y .

Khaliullin, R. Z.; Bell, A. T . A density functional theory study of the oxidation of methanol to formaldehyde over vanadia supported on silica, titania, and zirconia . J. Phys. Chem. B , 2002 . 106 7832 - 7838 . DOI: 10.1021/jp014695h http://doi.org/10.1021/jp014695h .

Blasco, T.; Nieto, J. M. L . Oxidative dyhydrogenation of short chain alkanes on supported vanadium oxide catalysts . Appl. Catal. A-Gen. , 1997 . 157 117 - 142 . DOI: 10.1016/S0926-860X(97)00029-X http://doi.org/10.1016/S0926-860X(97)00029-X .

Koten, G. V.; Hagen, H.; Boersma, J . Homogeneous vanadium-based catalysts for the Ziegler-Natta polymerization of α -olefins . Chem. Soc. Rev. , 2002 . 31 357 - 364 . DOI: 10.1039/B205238E http://doi.org/10.1039/B205238E .

Nomura, K.; Zhang, S . Design of vanadium complex catalysts for precise olefin polymerization . Chem. Rev. , 2010 . 111 2342 - 2362 . .

Cossee, P . Ziegler-Natta catalysis I. Mechanism of polymerization of α -olefins with Ziegler-Natta catalysts . J. Catal. , 1964 . 3 80 - 88 . DOI: 10.1016/0021-9517(64)90095-8 http://doi.org/10.1016/0021-9517(64)90095-8 .

Goldsmith, B. R.; Peters, B.; Johnson, J. K.; Gates, B. C.; Scott, S. L . Beyond ordered materials: Understanding catalytic sites on amorphous solids . ACS Catal. , 2017 . 7 7543 - 7557 . DOI: 10.1021/acscatal.7b01767 http://doi.org/10.1021/acscatal.7b01767 .

Lichtenstein, L.; Heyde, M.; Freund, H. J . Atomic arrangement in two-dimensional silica: From crystalline to vitreous structures . J. Phys. Chem. C , 2012 . 116 20426 - 20432 . DOI: 10.1021/jp3062866 http://doi.org/10.1021/jp3062866 .

Büchner, C.; Liu, L.; Stuckenholz, S.; Burson, K. M.; Lichtenstein, L.; Heyde, M.; Gao, H. J.; Freund, H. J . Building block analysis of 2D amorphous networks reveals medium range correlation . J. Non-cryst. Solid. , 2016 . 435 40 - 47 . DOI: 10.1016/j.jnoncrysol.2015.12.020 http://doi.org/10.1016/j.jnoncrysol.2015.12.020 .

Gao, X.; Bare, S. R.; Weckhuysen, B. M.; Wachs, I. E . In situ spectroscopic investigation of molecular structures of highly dispersed vanadium oxide on silica under various conditions . J. Phys. Chem. B , 1998 . 102 10842 - 10852 . DOI: 10.1021/jp9826367 http://doi.org/10.1021/jp9826367 .

Delley, M. F.; Núñez-Zarur, F.; Conley, M. P.; Comas-Vives, A.; Siddiqi, G.; Norsic, S.; Monteil, V.; Safonova, O. V.; Copéret, C . Proton transfers are key elementary steps in ethylene polymerization on isolated chromium(III) silicates . Proc. Natl. Acad. Sci. , 2014 . 111 11624 - 11629 . DOI: 10.1073/pnas.1405314111 http://doi.org/10.1073/pnas.1405314111 .

Conley, M. P.; Delley, M. F.; Núñez-Zarur, F.; Comas-Vives, A.; Copéret, C . Heterolytic activation of C―H bonds on CrIII-O surface sites is a key step in catalytic polymerization of ethylene and dehydrogenation of propane . Inorg. Chem. , 2015 . 54 5065 - 5078 . DOI: 10.1021/ic502696n http://doi.org/10.1021/ic502696n .

Feher, F. J.; Blanski, R. L . Olefin polymerization by vanadium-containing silsesquioxanes: Synthesis of a dialkyl-oxo-vanadium(V) complex that initiates ethylene polymerization . J. Am. Chem. Soc. , 1992 . 114 5886 - 5887 . DOI: 10.1021/ja00040a076 http://doi.org/10.1021/ja00040a076 .

Liu, B.; Fang, Y.; Xia, W.; Terano, M . Theoretical investigation of novel silsesquioxane-supported Phillips-type catalyst by density functional theory (DFT) method . Kinet. Catal. , 2006 . 47 234 - 240 . DOI: 10.1134/S0023158406020121 http://doi.org/10.1134/S0023158406020121 .

Quadrelli, E. A.; Basset, J. M . On silsesquioxanes’ accuracy as molecular models for silica-grafted complexes in heterogeneous catalysis . Coordin. Chem. Rev. , 2010 . 254 707 - 728 . DOI: 10.1016/j.ccr.2009.09.031 http://doi.org/10.1016/j.ccr.2009.09.031 .

Uchino, T.; Tokuda, Y.; Yoko, T . Vibrational dynamics of defect modes in vitreous silica . Phys. Rev. B , 1998 . 58 5322 - 5328 . .

Yoshida, Y.; Matsui, S.; Fujita, T . Bis(pyrrolide-imine) Ti complexes with MAO: A new family of high performance catalysts for olefin polymerization . J. Organomet. Chem. , 2005 . 690 4382 - 4397 . DOI: 10.1016/j.jorganchem.2005.01.038 http://doi.org/10.1016/j.jorganchem.2005.01.038 .

Tomoaki, M.; Terunori, F . High-performance olefin polymerization catalysts discovered on the basis of a new catalyst design concept . Chem. Soc. Rev. , 2008 . 37 1264 - 1277 . DOI: 10.1039/b708843b http://doi.org/10.1039/b708843b .

Sun, Q.; Cheng, R.; Liu, Z.; He, X.; Zhao, N.; Liu, B . Effect of F-modification over Phillips Cr/SiO 2 catalyst for ethylene polymerization . ChemCatChem , 2016 . 9 3364 - 3373 . .

Zhang, H.; Hu, Y.; Zhang, C.; Lee, D.; Yoon, K.; Zhang, X . Electrochemically assisted ethylene (co-)polymerization with a vanadium-based Ziegler-Natta catalyst . Catal. Commun. , 2016 . 83 39 - 42 . DOI: 10.1016/j.catcom.2016.04.024 http://doi.org/10.1016/j.catcom.2016.04.024 .

Adisson, E.; Deffieux, A.; Fontanille, M . Polymerization of ethylene at high temperature by vanadium-based heterogeneous Ziegler-Natta catalysts. I. Study of the deactivation process . J. Polym. Sci., Part A: Polym. Chem. , 1993 . 31 831 - 839 . .

Adisson, E.; Deffieux, A.; Fontanille, M.; Bujadoux, K . Polymerization of ethylene at high temperature by vanadium-based heterogeneous Ziegler-Natta catalysts. II. Study of the activation by halocarbons . J. Polym. Sci., Part A: Polym. Chem. , 1994 . 32 1033 - 1041 . .

Jin, Y.; Zhao, N.; Cheng, R.; He, X.; Liu, Z.; Liu, B . Remarkable promotion effect of sulfation over the SiO 2 -supported vanadium-oxide-based catalysts for UHMWPE . Macromol. Chem. Phys. , 2017 . 218 1700236 DOI: 10.1002/macp.v218.19 http://doi.org/10.1002/macp.v218.19 .

Espelid, Ø.; Børve, K. J . Theoretical models of ethylene polymerization over a mononuclear chromium(II)/silica site . J. Catal. , 2000 . 195 125 - 139 . DOI: 10.1006/jcat.2000.2986 http://doi.org/10.1006/jcat.2000.2986 .

Liu, B.; Fang, Y.; Terano, M . High resolution X-ray photoelectron spectroscopic analysis of transformation of surface chromium species on Phillips CrO x /SiO 2 catalysts isothermally calcined at various temperatures . J. Mol. Catal. A-Chem. , 2004 . 219 165 - 173 . DOI: 10.1016/j.molcata.2004.05.001 http://doi.org/10.1016/j.molcata.2004.05.001 .

Murray, J. S.; Politzer, P . Molecular electrostatic potentials and noncovalent interactions . WIREs. Comput. Mol. Sci. , 2017 . 7 e1326 DOI: 10.1002/wcms.1326 http://doi.org/10.1002/wcms.1326 .

Politzer, P.; Murray, J. S . The fundamental nature and role of the electrostatic potential in atoms and molecules . Theor. Chem. Acc. , 2002 . 108 134 - 142 . DOI: 10.1007/s00214-002-0363-9 http://doi.org/10.1007/s00214-002-0363-9 .

Tonosaki, K.; Taniike, T.; Terano, M . Origin of broad molecular weight distribution of polyethylene produced by Phillips-type silica-supported chromium catalyst . J. Mol. Catal. A-Chem. , 2011 . 340 33 - 38 . DOI: 10.1016/j.molcata.2011.03.005 http://doi.org/10.1016/j.molcata.2011.03.005 .

Hicks, J. C.; Mullis, B. A.; Jones, C. W . Sulfonic acid functionalized SBA-15 silica as a methylaluminoxane-free cocatalyst/support for ethylene polymerization . J. Am. Chem. Soc. , 2007 . 129 8426 - 8427 . DOI: 10.1021/ja0727870 http://doi.org/10.1021/ja0727870 .

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Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VOx/SiO2 UHMWPE Catalysts

Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VOx/SiO2 UHMWPE Catalysts

DOI：10.1007/s10118-019-2295-z

摘要

Abstract

关键词

Keywords

references

Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts

Mechanistic Study on the Dominant Promotion Effect of Al-/Ti-/Zr-modifications over the VO_x/SiO₂ UHMWPE Catalysts