Synthesis of silica gel as a Chromium-based catalyst support for polymerization of olefins

optimization of surface properties of silica gel such as specific surface area, total pore volume and average pore diameter have a significant role on the activity of the chromium based catalyst for ethylene production. Moreover, the final properties of polyethylene directly depend on the structural characteristic of silica gels which serve as support in heterogeneous catalyst. In this work we studied the preparation of silica gels from sodium silicate solution mixed whit sulphuric acid by sol-gel and aimed to achieve appropriate conditions in silica gels synthesis for making chromium based catalyst with high activity. For indicating the role of final PH, reaction temperature and ageing conditions on the silica gel structure, many different silica gel samples and chromium based catalyst were prepared. The polymerization results indicated that the pore volume of silica gel plays a crucial role in the catalyst activity. BET and BJH results showed that the pore volume of silica gels were influence by final PH of hydrosol and ageing conditions, directly

Keywords:

Sodium silicate , Sol-gel and Silica gel