Benzene Displacement on Imogolite

Abstract

The adsorption of 13 C-labeled benzene on imogolite has been studied on samples which had been evacuated and then heated to remove water below their decomposition point. After adsorption of labeled benzene, the samples were studied by nuclear magnetic resonance using non-spinning techniques. The results show that benzene can occupy more than one pore type and that water does not displace benzene from the intra-tube pores at atmospheric pressure. A further finding is that there are at least two types of adsorbed benzene in so called inter-tube pores, one of which is more rigidly held than that in intratube pores. The presence of disordered materials at the edge of pores could also play a role in altering the pore mouth thereby creating new types of pores. Moreover, where two tubes do not pack properly, space might be created where an adsorbed molecule may bind more tightly than expected in a conventional pore.

Ab initiosimulation of the structural and electronic properties of aluminosilicate and aluminogermanate natotubes with imogolite-like structure

“…Imogolites have adsorption properties of cations ͑Cd + , Cu + , Pd + ͒ 22 and ͑Ag + ͒, 23 neutral molecules like benzene, 24 water, 25 ammonia, 26 and possible applications in the energy storage-management of methane. 27 Additionally, the adsoption of chlorite by imogolites in a wide pH range 45 is wellknown, and it has been suggested the existence of a high point of zero charge in the outer parts of the imogolite, based on electrophoretic mobility studies.…”

“…17,21 Due to this surface area, together with the chemistry inherent to their surface, imogolites have been proposed as good metallic adsorbent of cations: ͑Cd + , Cu + , Pd + ͒, 22 ͑Ag + ͒, 23 and neutral molecules like benzene, 24 water, 25 and ammonia 26 with possible applications in the energy storage-management of methane. 27 In catalysis, imogolites have been investigated as a possible catalytic support of Cu and Pt particles.…”

Al/Fe isomorphic substitution versus Fe2O3 clusters formation in Fe-doped aluminosilicate nanotubes (imogolite)

“…This structure gives rise to three kinds of pores (Ackerman et al 1993;Wilson et al 2002) shown in Scheme 1: (i) pores A are intra-tube pores, 1.0 nm in diameter, lined by silanols, the related A surface being very hydrophilic and able to interact with probes like H 2 O, NH 3 and CO (Bonelli et al 2009;2013); (ii) pores B, 0.3-0.4 nm wide, are those among the three aligned NTs within a bundle, hardly accessible even to small molecules, like water (Ackerman et al 1993;Wilson et al 2002); (iii) pores C are disordered slit (meso)pores among bundles, the surface of which may interact with larger molecules, like phenol (Bonelli et al 2009) and 1,3,5-triethylbenzene (Bonelli et al 2013).…”

Use of isoelectric point and pH to evaluate the synthesis of a nanotubular aluminosilicate

“…Its stoichiometry is (OH) 3 AI 2 O 3 SiOH and it has at least two kinds of active surface sites, an internal one dominated by silanol groups (≡ Si-OH) and an external one dominated by aluminol groups (≡Al-OH) [8][9][10], both with pH-dependent surface charge. Because of the unique physicochemical characteristics of this IONt, various synthetic processes have been developed [9,[11][12][13][14][15], reinforcing its industrial applications.…”