Synthesis, characterization and catalytic activity of AlSBA-3 mesoporous catalyst having variable silicon-to-aluminum ratios

Description of the preferential transport of monovalent salts through Na–mordenite membrane: Physico-chemical aspects

“…The sort and the concentration of acid sites are controlled by the position of aluminum atoms in the structure or in the extra framework, while acid strength is widely controlled by the composition of the zeolite and also by the framework polarity. Recent work also shows that the quantity of acid sites increases when the Si/Al ratio decreases [2]. The sites responsible for this acidity are classified as Brönsted or Lewis sites [3].…”

Synthesis and characterization of conducting polypyrrole/SBA-3 and polypyrrole/Na–AlSBA-3 composites

“…Typical asymmetric and symmetric Si-O-Si stretching vibrations are centered at 1085 and 800 cm À1 , respectively. The band at 969 cm À1 corresponds to Si-OH vibrations of the surface silanols, characteristic of mesoporous silica, but absent in the Na-AlSBA-3, which indicates that the surface silanol groups around 964 cm À1 interact with the Al species and contribute to form the Si-O-Al superficial species in the process of preparation of Na-AlSBA-3 [39].…”

“…3B) show absorption bands at 1630, 1085, 964, 800 and 464 cm À1 . The peak at 1630 cm À1 is assigned to the OH bending vibrations of the water molecules adsorbed [39]. Typical asymmetric and symmetric Si-O-Si stretching vibrations are centered at 1085 and 800 cm À1 , respectively.…”

“…The BET specific surface area decreases with the Al content, from 1259 m 2 /g (SBA-3) to 810 m 2 /g for AlSBA-3 Si/Al = 10, due to the loading of the pores by guest species, as well as to the major contribution of the additional mass Al 2 O 3 in the sample [39]. Table 4 shows the area of the different composites.…”

H2S Removal Using ZnO/SBA-3: New Synthesis Route and Optimization of Process Parameters

“…Three-dimensional mesoporous materials are good candidates for this goal [47][48][49][50][51]. SBA-3 has a peculiar bimodal pore system, same as SBA-15, but can be synthesized in two hours instead of two days [52]. It is well known that bimodal three-dimensional arrangement of a mesoporous material improves mass transfer of guest species [53,54].…”