Synthesis and Catalytic Activity of the Mesoporous Silica Nanoparticles in Cumene Hydrocracking Conversion

Mesoporous Silica Nanostructures (MSN) with possess large pore size and volume, high surface area capable to take part in various chemical reactions and have been noticed. These catalysts are able to carry out the cracking conversion of the heavy hydrocarbons, bulky components and polymers to produce the light hydrocarbons or the small organic molecules. Since the pure MSN could not exhibit the catalytic activity due to the low acidity in its framework, introduction of some metals like Al, Zr and Ga to MSN promote its acidity and consequently increase the activity of the catalysts. Incorporation of Al as tetrahedral and octahedral structures generates the acid sites; tetrahedral is responsible of Lewis acid and octahedral is responsible of the Brønsted acid sites. The XRD pattern represented a decreasing in the intense peak for the Al loaded sample in compare to MSN which indicated to reduce in ordered structure. The pyridine-FTIR spectra of HAlMSN catalyst showed the vibrational bands at 1445 and 1545 cm-1 which were related to the Lewis and Brønsted acid sites, respectively. The BET analysis revealed that the surface area was decreased by loading Al and the catalytic activity results showed that the quality of the products was depend on the concentration and distribution of Al content and temperature. The rate of cumene conversion increased with enhancing the amount of Al into the framework and raising the temperature.