Mechanical properties of mesoporous silicas and alumina–silicas MCM-41 and SBA-15 studied by N2 adsorption and 129Xe NMR

• Published in: Microporous and mesoporous materials 2001-04, Vol.44-45, p.775-784
• Main Authors: Springuel-Huet, M.-A, Bonardet, J.-L, Gédéon, A, Yue, Y, Romannikov, V.N, Fraissard, J
• Format: Article
• Language: English
• Subjects: 129Xe NMR; Mechanical stability; Mesoporous aluminosilicate; N2 adsorption
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/S1387-1811(01)00260-8

Purely siliceous and Al-containing MCM-41 and SBA-15 materials have been prepared with pore diameters of 2.4–3.0 nm for MCM-41 and 6.5–7.5 nm for SBA-15. The effect of compression on the mesopore structure has been studied by N2 adsorption–desorption, X-ray diffraction and 129Xe NMR experiments. The pore size distributions obtained from N2 adsorption data show that the mesopore structure is partially destroyed and that small size pores are formed at the expense of the original ones (in the loose powder) when the powder is compressed at high pressure (up to 520 MPa). The 129Xe NMR spectra are interpreted in terms of an exchange between adsorbed Xe (in the channels) and gaseous Xe atoms (in the interparticle spaces), which depends on the particle size and the compaction of the powder. For both MCM-41 and SBA-15 materials, the Al-containing samples are more fragile than the purely siliceous materials.