Pyridylimine cobalt (II) and nickel (II) complex-functionalized multi-walled carbon nanotubes and their catalytic activities for ethylene oligomerization
4th International Conference on Nanotek & Expo
December 01-03, 2014 DoubleTree by Hilton Hotel San Francisco Airport, USA

Saad M Alshehri and Tansir Ahamad

Posters: J Nanomed Nanotechnol

Abstract:

Multi-walled carbon nanotubes (MWCNTs) were covalently functionalized with pyridylimine and its metal complexes. The synthesized compounds were characterized by several analytical techniques. The pyridylimine metal complexfunctionalized multi-walled carbon nanotubes [Pyr-M(II)-MWCNTs] were evaluated as catalyst precursors for ethylene oligomerization with methylaluminoxane (MAO) used as an activator at different Al/M [M(II) =Co(II) and Ni(II)] ratios and at two different ethylene pressures. [Pyr-Co(II)-MWCNTs] (C1) and (Pyr-Ni(II)-MWCNTs] (C2) were isolated as solid materials in good yield. Complex C2 was found to be a more effective pre-catalyst than C1 in the presence of MAO. Thus, C2 exhibited a maximum catalytic activity of 1.89?106 g mol-1(Ni) h-1 bar-1 with an Al/Ni ratio of 2000:1 at room temperature with a 5 atm pressure of ethylene, whereas C1 exhibited a maximum activity of 1.87?106 g mol-1(Co) h-1 bar-1 in similar condition. When the Al/Co ratio was increased at a 1 atm pressure of ethylene, the catalytic activity of the pre-catalyst increased, and the process became more selective towards higher oligomers. The catalytic activity and selectivity with 1-decene using C1 were 3.02?105 g mol-1(Co) h1 bar-1 and 72%, respectively, with 5 atm ethylene and an Al/Co ratio of 200:1