Epoxidation of propene on vanadium species supported on silica supports of different structure

Catalytic Performance of Zeolite‐Supported Vanadia in the Aerobic Oxidation of 5‐hydroxymethylfurfural to 2,5‐diformylfuran

“…UV/Vis spectrophotometric analysis of the samples was consistent with the presence of isolated vanadium species and the absence of crystalline V 2 O 5 35. A broad band centered at approximately 250 nm, assigned to the charge transfer transitions involving vanadium in tetrahedral coordination in isolated species, could be identified in the 1, 3, and 10 wt % catalysts 36–38. Another band at approximately 400 nm (attributed to polymeric chains) was observed in the 3 and 10 wt % V 2 O 5 /H‐beta catalysts.…”

MCF Material as an Attractive Support for Vanadium Oxide Applied as a Catalyst for Propene Epoxidation with N2O

“…The vanadium-supported catalysts, obtained by a simple impregnation of an aqueous solution of VOSO 4 on MCF mesoporous material, characterised by high vanadium distribution, appeared to be highly effective in propene epoxidation at temperatures below 673 K, offering propene oxide yields much higher than those provided by previously studied vanadium containing catalysts [14,15,19] as presented in Fig. 6.…”

“…Previous investigations concerning the use of vanadia-based silica supported catalysts for propene epoxidation have shown that various parameters of the catalysts, including aggregation state and reducibility of vanadium species, acid/base properties, and vanadium content, need to be considered to account for the catalytic behavior noted for the selective oxidation of propene [15,19]. It has been shown that catalysts with high vanadium dispersion show better performance in a number of oxidation reactions such as propane oxydehydrogenation [31], methanol partial oxidation [32], and also in selective propene oxidation [15,19,33]. The presence of an isolated tetrahedral vanadium oxide species is essential as it facilitates the interaction with -N δ− =N δ+ =O species, a mezomeric form of N 2 O, with the formation of mildly electrophilic oxygen forms.…”

“…The catalytic activity calculation has been described elsewhere [19]. It was evaluated from the concentrations of the products detected (i.e., propene oxide, acrolein, acetone, propionaldehyde, CO, and CO 2 ) and the remaining propene.…”

One-pot synthesis of vanadium-containing silica SBA-3 materials and their catalytic activity for propene oxidation

“…The best results were obtained with catalysts prepared by impregnation of silica SBA-3 with vanadium ions. 23 It was evidenced that isolated vanadium species are responsible for high selectivity towards propene oxide (PO), whereas the oligomeric vanadium species or bulk vanadia result in propene oxide isomerization and total oxidation reactions. Since the above mentioned vanadium catalysts, prepared by means of impregnation method, indicated various vanadium species such as isolated, oligomeric, and even bulk vanadia at high V loadings, it was interested to check if the vanadium containing SBA-3 materials prepared by direct synthesis with well-dispersed isolated vanadium species could present enhanced catalytic activity in the studied reaction.…”