Influence of the Ti precursor on the properties of Ti–pillared smectites

Abstract

The pillaring of smectites (two saponites and a montmorillonite) with various Ti precursors was studied. The minerals were intercalated with ‘classical ’ Ti precursors, such as titanium tetrachloride and titanium tetraethoxide, and also with new precursors, such as solutions of titanium tetraisopropoxide in acetic acid, or titanium (bis (ethylacetoacetato) diisopropoxide) in acetone. A complete characterization of the intercalated solids was carried out and a comparison of the properties of the solids as a function of the precursors used in the intercalation established. The influence of the severe conditions in which the intercalation with Ti oligomers is usually carried out (low pH and/or high temperature) on the properties of the intercalated solids was analysed. Intercalation with TiCl4 and Ti(EtO)4 strongly affected the structure of the clays, not by acid attack on the octahedral sheet, but mainly by disaggregation of particles. Ti(isop)4 was found to be less aggressive for the clays, while Ti(etacet)2(isop)2 did not form pillared solids but organo-clays, and therefore was of no use as a pillaring agent. The solids were thermally stable up to 300°C, showing a high specific surface area.

Photodegradation of 1,2,4-Trichlorobenzene on Montmorillonite–TiO2 Nanocomposites

“…In addition, small effects due to C-H bonds were observed around 3000 cm −1 , assignable to contamination from organic vapors in the laboratory. These effects were more intense in MTi1, suggesting the probable presence of residual isopropoxide groups in the Ti species, as reported previously [31]. The thermogravimetric curve of samples MTi1 and MTi2 (Figure 4) showed a similar behavior to that of natural montmorillonite ( Figure S1, Supplementary Material).…”

Physicochemical properties of vanadium impregnated Al-PILCs: Effect of vanadium source

“…8. As in consistency with the previous literature, the TGA curves for all samples showed a progressive mass loss that began just above room temperature and was essentially slowed at 650 • C [21,[56][57][58]. The uncalcined Al-bentonite (just pillared and dried at room temperature) and Al-PILC (calcined at 300 • C then left at room temperature) showed higher total mass losses approximately 19% and 15%, respectively.…”

Clay-Supported Metal Oxide Nanoparticles in Catalytic Advanced Oxidation Processes: A Review

“…As organo-titanium compounds, the interaction between precursors and native cations was not in ion exchange mode; thus, the release of exchangeable Ca 2+ and Na + cations did not occur. In contrast, this occurred in the use of TiCl 4 or TiOCl 3 [ 115 ].…”