Supported Al-Ti bimetallic catalysts for 1-decene oligomerization: Activity, stability and deactivation mechanism

摘要

A variety of supported bimetallic catalysts were prepared through immobilization of AlCl3 and TiCl4 on different porous materials and used for the oligomerization of 1-decene in a fixed-bed reactor. The supported catalysts were characterized by various techniques including X-ray photoelectron spectroscopy (XPS), Al-27 MAS NMR, N-2 adsorption, adsorbed pyridine infrared (Py-IR), thermogravimetry and differential scanning calorimetry (TG-DSC), energy-dispersive spectrometry (EDS), and content measurement of active species. Their catalytic activity was examined and the underlying deactivation mechanism was explored. The initial catalytic activity was observed to be a linear function of the chlorine content of the supported catalyst. A catalyst using a coal-derived activated carbon support has the highest loading and exhibits the highest yield of polyalphaolefin (PAO), while a gamma-Al2O3-supported catalyst gives higher stability. In addition, thermal treatment of the gamma-Al2O3-supported catalyst results in reduced initial activity but enhanced stability. Both the loss of active species and the blockage and coverage of the pore structure by oligomers account for the deactivation of the supported catalyst. (C) 2016 Elsevier Inc. All rights reserved.