Journal
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
Volume 584, Issue -, Pages -Publisher
ELSEVIER
DOI: 10.1016/j.colsurfa.2019.124020
Keywords
Non-hydrolytic sol-gel process; Supported metallocenes; Ethylene polymerization; Silica; SAXS
Categories
Funding
- CNPq [309002/2015-0]
- FAPERGS [16/2551-0000470-6]
- CAPES
- LNLS [D11A-SAXS1-8691]
Ask authors/readers for more resources
The immobilization of Cp2ZrCl2 was performed by entrapment within the binary oxides SiO2-CrO3, SiO2-MoO3 and SiO2-WO3 using a non-hydrolytic sol-gel route. Catalyst performance was evaluated in ethylene polymerization. The highest catalyst activity was found with a lower metal chloride:Si ratio and catalyst bearing W moieties. The catalyst and oxide matrices were characterized by complementary techniques (nitrogen porosimetry, small angle X-ray scattering, Fourier Transform infrared spectroscopy, X-ray photoelectron spectroscopy, and differential pulse voltammetry). The interaction between the binary oxide support and the immobilized metallocene reduced the electron density on the Zr centers, enabling the activation reaction to occur with lower concentrations of the methylaluminoxane (MAO) co-catalyst (Al/Zr = 500). The catalytic activity showed a direct relationship with the size and shape of the mass fractal. The results demonstrate that the entrapping method allows for the generation of a catalyst system in which part of the activation process may be attributed to the support.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available