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, N 2 adsorption, scanning electron micrographs (SEM), transmission electron micrographs (TEM) and 27 Al 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.

Effect of tetrahedral aluminum on the catalytic performance of Al–SBA-15 supported Ru catalysts in Fischer–Tropsch synthesis

“…The very broad diffraction peak at a 2y of around 251 is typical reflection of amorphous silica. 22 The diffraction peak assigned to metallic Ru (JCPDS 00-006-0663) at a 2y of around 441 is observed for all supported catalysts. 21 27 Al MAS NMR spectra of the supports are shown in Fig.…”

Ru catalysts supported on Al–SBA-15 with high aluminum content and their bifunctional catalytic performance in Fischer–Tropsch synthesis

“…The very broad diffraction peaks at 2θ around 23°a re characteristics of amorphous silica. 22 The absence of alumina reflections in Al-SBA-15 with lower Al/Si ratio (0.2, 0.5) suggests that the aluminum is homogeneously dispersed in the structure of Al-SBA-15. 19 While in Al(1.0), a broad peak at 67°is observed, indicating the formation of γ-Al 2 O 3 by Al species without incorporation into the framework.…”

The Synthesis of Al-SBA-16 Materials with a Novel Method and Their Catalytic Application on Hydrogenation for FCC Diesel

“…Py-IR spectra of NiMo/​AS- x are shown in Figure . The peaks related to the physisorbed pyridine at 1444 and 1595 cm –1 cannot be observed after degassing at 200 and 350 °C, demonstrating that pyridine chemisorbed on the surface of NiMo/​AS- x catalysts . The peaks at about 1640 and 1540 cm –1 should be assigned to Brönsted acid sites.…”

“…The authors attributed the reason to the contribution of high dispersion states of Mo active species . A postgrafting method to synthesize Al-SBA-16 materials has been reported by Ma et al . Moreover, the effect of Si and Al molar ratios on the catalytic performances of phenol tert -butylation reaction showed that Al-SBA-16 performed a much higher catalytic activity than the mesoporous Al-SBA-15 material, which should be ascribed to that Al-SBA-16 materials with cagelike mesostructures provided high accessibility to the reactant molecules.…”

“…Moreover, the effect of Si and Al molar ratios on the catalytic performances of phenol tert -butylation reaction showed that Al-SBA-16 performed a much higher catalytic activity than the mesoporous Al-SBA-15 material, which should be ascribed to that Al-SBA-16 materials with cagelike mesostructures provided high accessibility to the reactant molecules. Furthermore, the catalytic activities of Al-SBA-16 increased with Si and Al molar ratios, peaking at 20 …”