Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9617855 | Microporous and Mesoporous Materials | 2005 | 7 Pages |
Abstract
This paper describes a simple procedure for the synthesis of saponites with isomorphous substitution of Si4+ by B3+ and Ga3+ below 100 °C and at 1 atmosphere. The XRD pattern of the Ga- and B-substituted saponites are similar to Al-substituted saponites. The 71Ga MAS-NMR spectra of Ga3+ containing Mg- and Zn-saponite show two broad peaks at approximately 25 and 180-195 ppm, attributed to Ga6 and Ga4, respectively. the dimensions of Mg-saponite particles are considerably smaller than those of Zn-saponites. The lateral dimensions of the platelets of B3+ containing Mg-saponites range between 40 and 100 nm, exhibiting hardly any stacking after 20 h of synthesis, while the platelets of the Zn-saponites are 200-350 nm in length with some degree of stacking. B3+ containing Mg-saponite exhibits a broad double signal at 12.6 and 9.0 ppm of a low intensity, together with a sharp peak at â0.8 ppm, presumably corresponding to BO3 and BO4, respectively. 29Si MAS-NMR on the B3+ containing saponites reveals two signals at approximately â85 due to Q2 Si(OB) and â96 ppm corresponding to Q3 Si(OB).
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Catalysis
Authors
R.J.M.J. Vogels, J.T. Kloprogge, J.W. Geus,