Hydroxylation and dealumination of a metakaolinite-rich brick under acid conditions, and their influences on metal adsorption: One- and two-dimensional (<sup>1</sup>H, <sup>27</sup>Al, <sup>23</sup>Na, <sup>29</sup>Si) MAS NMR, and FTIR studies - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Microporous and Mesoporous Materials Année : 2016

Hydroxylation and dealumination of a metakaolinite-rich brick under acid conditions, and their influences on metal adsorption: One- and two-dimensional (1H, 27Al, 23Na, 29Si) MAS NMR, and FTIR studies

Résumé

Brick was treated at 90°C with a 6 M solution of HCl at various reaction times (1-26 h), leading to hydroxylation and dealumination of brick metakaolinite. Alkali treatment of HCl-treated brick improved the adsorption performance of this material in the removal of divalent metals (Fe2+ and Pb2+). The effects of chemical and thermal treatments on the structure of the brick were examined using one- (1D) and two-dimensional (2D) NMR and FTIR spectroscopies. The applied techniques included: (1D) 1H, 23Na, 29Si and 27Al MAS NMR; and 27Al/1H D-HMQC and 1H/29Si CP-HETCOR NMR. Correlation NMR methods provided new insights into the complicated issue relative to the nature of generated 1H atoms and their connectivity/proximity with neighboring 27Al and 29Si atoms in hydroxylated metakaolinite. The contribution of Brönsted acid sites before and after their neutralization by NaOH on the metal-adsorption process was interpreted in terms of "active" negatively charged sites at the material surface. The metal-adsorption capacity of neutralized brick was found to be intimately related to its Na amount and/or number of ΞSiO-Na+ and ΞAlO-Na+ functions.
Fichier non déposé

Dates et versions

hal-01388538 , version 1 (27-10-2016)

Identifiants

Citer

O. Allahdin, M. Wartel, G. Tricot, B. Revel, A. Boughriet. Hydroxylation and dealumination of a metakaolinite-rich brick under acid conditions, and their influences on metal adsorption: One- and two-dimensional (1H, 27Al, 23Na, 29Si) MAS NMR, and FTIR studies. Microporous and Mesoporous Materials, 2016, 226, pp.360 - 368. ⟨10.1016/j.micromeso.2016.02.028⟩. ⟨hal-01388538⟩
28 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More