1H and 51V high-resolution solid state nuclear magnetic resonance studies of supported V2O5/TiO2 catalysts

Formation of Active Sites for Selective Toluene Oxidation during Catalyst Synthesis via Solid-State Reaction of V2O5 with TiO2

“…Two types of hydroxyl groups are known to be present on the titania surface (26,27). Bridging acidic hydroxyl groups can be removed from the catalyst surface at temperatures lower than isolated basic groups [27].…”

“…Bridging acidic hydroxyl groups can be removed from the catalyst surface at temperatures lower than isolated basic groups [27]. Desorption of water at elevated temperatures leads to the removal of weakly adsorbed acidic hydroxyl groups, resulting in the formation of basic bridging oxygen (Ti-O-Ti).…”

Reactivity of the V2O5–TiO2-anatase catalyst: role of the oxygen sites

“…There are two reasons for the use of clusters to represent the active phase: first, active species on the catalyst surface are known to be dispersed as monomers or dimers [9,[14][15][16][17][18][19], and second because of their stability in gas phase already investigated by collision-induced dissociation, CID, experiments [20] and DFT calculations [21,22]. The cluster calculations have been performed with the Gaussian98 code [23] at a B3LYP level with a DB-31G* basis set for all atoms (see details in Ref.…”

“…Its efficiency in SCR is related to the dispersion of the active phase and the presence of dimeric and monomeric species depending on the concentration [9,[14][15][16][17][18][19]. The support plays a crucial role on the reactivity of the catalyst, not only in a physical way (favoring dispersion or improving conditions during synthesis) but also because of the chemical interaction with the active phase and molecules in the environment.…”

Gas-phase catalytic oxidation ofm-xylene

“…According to Ref. [13], the surface should have associates of tetrahedrally coordinated double-bonded vanadium for the oxidation of o-xylene to phthalic anhydride. One can assume that during m-xylene oxidation to 3-methylbenzoic acid, introduction of the second oxygen into the m-xylene molecule also requires the presence of vanadium associates.…”