Methylalumoxane MCM-41 as Support in the Co-Oligomerization of Ethene and Propene with [{C2H4(1-indenyl)2}Zr(CH3)2]

Abstract

Superior to the homogeneous catalyst or physisorbed catalyst system is a system with the ansa-metallocene catalyst [{C H (1-ind) }Zr(CH )] on a support formed by covalently anchoring methylalumoxane (MAO) on the internal pore walls of MCM-41. This system is a highly active and shape-selective mesoporous host in the co-oligomerization [shown schematically in Equation (a)] of ethene and propene with ansa-metallocenes. TMA=trimethylaluminum, ind=indenyl.

Catalysis of ethylene to linear low‐density polyethylene with iron‐based diimine complex immobilized on calcosilicate and silica‐supported rac‐Et(Ind)2ZrCl2

“…Moreover, high selectivity for α‐olefins from ethylene oligomerization with the oligomerization catalyst was still maintained. The results indicated that layers of CAS‐1 effectively prevented the active sites of oligomerization catalyst from being deactivated due to bimolecular interaction as in the case of homogeneous catalysts 23–26. Different from homogeneous iron‐based diimine complexes, there is no need for external addition of MAO to initiate the oligomerization of ethylene under such circumstances.…”

Copolymerization of ethylene and in situ‐generated α‐olefins to high‐performance linear low‐density polyethylene with a two‐catalyst system supported on mesoporous molecular sieves

“…An increase of the size of the α‐olefin molecule led to a weakening ‘comonomer effect’ and decreased incorporation of the comonomer38 when zeolites (NaY and HY, Φ < 2 nm) were used to support metallocene compounds 38–40. The use of MCM‐41 molecular sieve gave similar results41 except that bulky comonomer molecules are difficult to diffuse near the active metal sites to realize complexation 42. Further increase of the pore size to 7.2–15 nm resulted in very low activity in ethylene copolymerization with hex‐1‐ene, the reason for which is unclear 43, 44…”

α-Zirconium phosphonates as new supports for metallocene catalysts

“…The suspension was transferred into a centrifuge vessel, washed five times with 70 mL of toluene and the residue dried in vacuum. The yields were essentially quantitative; small losses being due to the washing process: ␣-Zr(O 3 PMe) 2 (Cp 2 ZrCl 2 ) 0.002 (13), ␣-Zr(O 3 P n Bu) 2 (Cp 2 ZrCl 2 ) 0.002 (15), ␣-Zr(O 3 P iso Bu) 2 (Cp 2 ZrCl 2 ) 0.001 (16), ␣-Zr(O 3 POct) 2 ·(Cp 2 ZrCl 2 ) 0.008 (17), ␣-Zr(O 3 PPh) 2 ·Cp 2 ZrMe 2 ) 0.003 (18).…”

“…However, for most industrial applications catalyst heterogenization is required [1][2][3]. Most supporting concepts for the heterogenization of metallocene catalysts use different types of amorphous silica [4][5][6][7][8], although MgCl 2 [9][10][11], alumina [12], zeolites [13,14], clays [15,16], mesoporous silicates [17][18][19][20][21] and polymers [22][23][24][25][26][27][28] have also been used. We report here the use of zirconium phosphonates as supports for metallocene catalysts.…”