An Easy Route to Synthesize Novel Mesostructured Silicas Al/SBA-16 and Its Catalytic Application

Abstract  

Al-containing SBA-16 (with different Si/Al molar ratios) was prepared by an easy post-grafting method using F127 as structure-directing agent and aluminum isopropoxide as Al source. The structure of the solid catalyst was fully characterized by X-ray diffraction (XRD) analysis, N₂ adsorption, scanning electron micrographs (SEM), transmission electron micrographs (TEM) and ²⁷Al MAS NMR. The results indicated that the materials possess three-dimension caged-like mesostructure and Al was successfully incorporated into the SBA-16 framework. The acid properties have been estimated by FT-IR of pyridine adsorption (Py-IR). Among various Si/Al ratios, Al/SBA-16 with Si/Al ratio 20 performed good catalytic activity for the tert-butylation of phenol. Compared to hexagonal mesoporous Al/SBA-15, Al/SBA-16 showed higher catalytic properties due to its cage-like mesostructure, which could make the active acid sites more accessible to the reactant.