On the Properties of a Novel V-Containing Saponite Catalyst for Propene Oxidative Dehydrogenation

Abstract

Vanadium ions are introduced for the first time in the framework of saponite clay (V-SAP) by hydrothermal direct synthesis. The physico-chemical properties and redox behaviour of the obtained material are discussed together with its catalytic performances in propene ODH, and its activity in the formation of poly-condensed aromatic products.

Physico-chemical Properties, Biological and Environmental Impact of Nb-saponites Catalysts for the Oxidative Degradation of Chemical Warfare Agents

“…The conventional synthetic protocol, previously used to prepare saponite clays, was modified to allow the insertion of Nb(V) ions within the framework, aiming to obtain three novel solids with different characteristics in terms of oxidizing and Brønsted acid properties. The three Nb‐containing clays were prepared following a typical one‐pot hydrothermal procedure . Nb(V) ions were introduced into the inorganic matrix starting from two different metal precursors: niobium(V) ethoxide, employed in the Nb‐SAP20(Et) and Nb‐SAP110(Et) preparations, and niobium(V) chloride salt, used for the Nb‐SAP20(Cl) solid.…”

Acid/Vanadium‐Containing Saponite for the Conversion of Propene into Coke: Potential Flame‐Retardant Filler for Nanocomposite Materials

“…In addition, a broad band at 2140 cm −1 , owing to the stretching vibration of CO that is condensed in a liquid‐like state inside the saponite porosities that are generated by particle aggregation, is also observed 13. 17…”

“…Three broad bands at about 340, 430, and 600 nm are also observed. The first two bands indicate the presence of V 2 O 5 ‐like oligomers, which are probably located in extra‐framework positions, whilst the broad absorption at higher wavelength is related to dd transitions of the V 4+ cations, thus indicating that the solid contains both V 5+ and V 4+ species 17. 20…”

“…Recently, some of us reported a new vanadium‐containing synthetic clay, which is a potentially interesting material for these kinds of applications 17. This material is a synthetic saponite and contains both vanadium ions, by partially replacing silicon ions in the tetrahedral sheet, and extra‐framework vanadium species (Figure 1).…”

“…The co‐presence of vanadium‐ and silicon atoms in the same layer generates Brønsted acid sites that are able to produce coke from propene 17. Thus, the ODH reaction of propene was used as a test reaction for a fast screening of additives because it can improve the capacity of a given catalyst to favor: 1) the production of volatile oxygenated products, 2) the production of coke, and 3) the total combustion of propene.…”