SBA-15 as a Support for Nickel-Based Catalysts for Polymerization Reactions

Abstract

Two mesoporous SBA-15 materials with different morphologies (spherical and fiber-shaped) were synthesized and evaluated as supports for nickel-based catalysts for polymerization reactions. The supports were pretreated with trimethylaluminum (TMA), and the catalyst dibromo-bis(4-amino-2,3,5,6-tetramethylimino)acenaphthene nickel(II) was attached to the supports and activated with TMA or MAO (methylaluminoxane). Characterization showed that the insertion of cetyltrimethylammonium bromide (CTABr) as a cosurfactant led to spherical SBA-15 with a decrease in particle and pore sizes to 4.8 nm compared to 6.5 nm in traditional fiber-shaped SBA-15. The spherical SBA-15 showed thicker walls than the fiber-shaped SBA-15, attributed to the increase in functional groups of the cosurfactant. The different spherical and fiber-shaped morphologies did not show any significant difference in the productivity of polyethylene. The catalyst supported on spherical SBA-15 materials showed 58% productivity compared to its homogeneous analogue using TMA as a cocatalyst.

Pt/Ga-SBA-15 composites synthesis and characterization

“…Pristine mesoporous SBA-15 had typical texture with 819 m 2 /g surface area (SBET), pore volume (Vp) of 1.05 cm 3 /g and average pore diameter (from corresponding PSD, Figure 1b) of 5.55 nm. Those properties nicely corresponded to expected values for SBA-15 matrices (500 < SBET < 1300 m 2 /g, 0.82 < Vp < 1.69 cm 3 /g) commonly reported in the literature for such type of mesostructured SiO2 [18].…”

“…Pristine mesoporous SBA-15 had typical texture with 819 m 2 /g surface area (SBET), pore volume (Vp) of 1.05 cm 3 /g and average pore diameter (from corresponding PSD, Figure1b) of 5.55 nm. Those properties nicely corresponded to expected values for SBA-15 matrices (500 < SBET < 1300 m 2 /g, 0.82 < Vp < 1.69 cm 3 /g) commonly reported in the literature for such type of mesostructured SiO2[18].However, all Ga-modified solids at various contents had decreased surface area as to that of pristine SBA-15. Fifth column of Table1shows theoretical surface area of composites considering incorporation of essentially nonporous Ga2O3 component in SBA-15 matrix ( b SBET), pointing out to that in samples of the lowest Ga content gallium oxide domains could be partially plugging well-ordered mesoporous siliceous network.…”

Improving platinum dispersion on SBA-15 by titania addition

“…Pristine mesoporous SBA-15 had typical texture with 818 m 2 /g surface area (S BET ), pore volume (V p ) of 1.05 cm 3 /g and average pore diameter (from corresponding PSD, Figure 1(b)) of 5.78 nm. Those properties nicely corresponded to expected values for SBA-15 matrices (500< S BET >1300 m 2 /g, 0.82< V p >1.69 cm 3 /g) commonly reported in the literature for such type of mesostructured SiO 2 (Devi et al, 2018;Schwanke et al, 2018). However, all Ti-modified solids at various contents had decreased surface area as to that of pristine SBA-15.…”

Catalytic Removal of Toluene from Air Streams by Cobalt Oxide Supported on Sepiolite

“…Recently, researchers have focused on the porous adsorbent materials as metal oxide supports for production of catalysts. Some of the most commonly used porous materials are activated carbon, 28 alumina, 29 diatomite, 30 silica 31 and zeolite. 32 Sepiolite is a member of clay mineral family with the formula of Mg 8 Si 12 O 30 (OH) 4 ‧4H 2 O‧nH 2 O.…”