Catalytic epoxidation of allylic alcohol (E)-2-Hexen-1-ol over vanadium supported on unsulfated and sulfated titanium pillared montmorillonite catalysts: Effect of sulfate groups and vanadium loading

Allylic oxidation of cyclohexene over ruthenium-doped titanium-pillared clay

“…This means that the available ruthenium active sites were isolated; they increased the catalytic activity. Similar behaviors were observed by J. Arfaoui et al 83 with vanadium supported Ti-…”

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

“…The other way, there might be a nonhomogeneous vanadium distribution in the layered structure. The observed decreases in the peak intensity and d 001 values were consistent with the data reported in the literature [25,32,40,42,43,45]. Decreases occurred in the order of impregnation from solution (I), washing after wet impregnation (WWI) and wet impregnation (WI) for both metal sources.…”

“…The broad bands ascribed to interlayer water and OH bonding in the region 3700-3000 cm −1 reflected drastic changes after the vanadium impregnation. The signals assigned to the V-OH species at around 3650 cm −1 were probably superimposed on that of the H-bonded silanols in all of the impregnated samples, whereas the intensity of the interlayer water band at 3410 cm −1 decreased [40,51]. Most of the V-O and V-O-V stretching bands in the ranges of 1050-920 cm −1 , 830-820 cm −1 and 600-400 cm −1 overlapped with the characteristic bands of the bentonite.…”

“…A small OH bending vibration assigned to the Al 2 OH also occurred at 3205 cm −1 . The strong intense band at 1630 cm −1 was the bending vibration of the hydroxyl and absorbed interlayer water molecules of the room-dried host clay and its intensity decreased in the pillared and metal impregnated samples because a portion was removed by calcination [40,50,52].…”

“…The band corresponding to disulfate species created in the sulfur containing vanadium source at 1398 cm −1 were combined with the calcite band of the starting material and became a little bit significant for the wet impregnated sample. The shoulder at 1235 cm −1 attributed to the S-O stretching vibration was somewhat exacerbated in the samples impregnated with the sulfur containing vanadium source, indicating the formation of monosulfate species [40,54].…”