Vapour-phase trimerization of formaldehyde to trioxane catalysed by 1-vanado-11-molybdophosphoric acid

On the Adsorption of Formaldehyde at High Temperatures and Zero Surface Coverage

“…The former would concern changes in HCHO produced as a consequence of the adsorption temperature or as a catalytic behavior of the carbon material inside the column. It is known that HCHO is a very versatile molecule which is easily capable of several chemical changes, including polymerization. ,− Experiments were carried out in order to determine whether the injected molecule was pure HCHO or whether some other molecule was produced because of the injection temperature. These experiments consisted in heating paraformaldehyde in a TGA−FTIR system in order to monitor the product.…”

Vanadium-substituted Keggin heteropolycompounds as catalysts for ecofriendly liquid phase oxidation of 2,6-dimethylphenol to 2,6-dimethyl-1,4-benzoquinone

“…H 4 PMo 11 VO 40 (M11PV1A) and H 9 PMo 6 V 6 O 40 (M6-PV6A) were prepared by a hydrothermal synthesis method [15]. M11PV1A synthesis according to the following procedure is presented as example: a stoichiometric mixture of 0.98 g of phosphoric acid, 0.91 g of vanadium pentoxide and 14.4 g of molybdenum trioxide was suspended in 150 ml of distilled water.…”

Vanadium-Substituted Phosphomolybdic Acids for the Aerobic Cleavage of Lignin Models—Mechanistic Aspect and Extension to Lignin

“…H 6 PV 3 was synthesized through the attack of MoO 3 (Acros Organics, Illkirch, France) and V 2 O 5 (Sigma-Aldrich Chemie S.a.r.l., Saint-Quentin Fallavier, France) by H 3 PO 4 (purity 85%, Carlo Erba, Val-de-Reuil, France) in refluxing water according to a procedure adapted from Kern et al [31]. Hence, 0.39 g (3.3 mmol) of H 3 PO 4 was dissolved in 200 mL of water and 3.9 g of MoO 3 (27.3 mmol) and 0.92 g (5.1 mmol) of V 2 O 5 were added.…”

“…However, an increase of vanadium degrades the stability of the H 3+x PV x [30] that may lead to loss of activity as observed by Odyakov et al As a result, in this study, H 6 PV 3 will be chosen as in the work of El Aakel et al [14], because it seems to be the best compromise between oxidative power and stability. H 6 PV 3 was synthesized through the hydrothermal pathway which just consists in refluxing the starting oxides and phosphoric acid in water without any addition of an external reagent [31] on the contrary to the most used etherate [32] (that involves a hazardous solvent [33] and strong acids) and oxo-peroxo [34,35] procedures usually used for such material. Already, such a pathway was attempted by Grate et al for the synthesis of a H 6 PV 3 0.30 M in water.…”