Revealing the effects of high Al loading incorporation in the SBA-15 silica mesoporous material

High aluminum loading incorporation in the SBA-15 silica structure was investigated. Different Si/Al molar ratios (15, 10, and 2) were evaluated. The aluminum-containing materials (Al-SBA-15) prepared by “pH adjusting” method with modifications. mesoporous of demonstrated type IV isotherms. pore changed from a cylindrical to slit-like presence higher content. X-ray diffraction (XRD) high-resolution transmission electron microscopy (HRTEM) pointed out that structural order is compromised load Al-SBA-15 materials, although preserved. Higher Al increases total quantity Lewis acid sites as well generates Brönsted sites. CO adsorption FTIR spectroscopy suggests into generation Si–O–Al linkage corroborated UV–Vis DRS due peak centered at 241 nm related Al-O bond, which ascribed four-coordinated framework structure. XPS spectra 2p suggested species are less oxidized than Al2O3 phase giving some indication framework. 27Al MAS NMR results revealed tetrahedral oxygen coordination environment for 15 10. Aluminum both octahedral environments evidenced ratio 2.