Heteropoly acids as oxidation catalysts in synthesis of K-vitamins

P−Mo−V heteropoly acids as catalysts for oxidation of 2,6-dialkylphenols to the corresponding 2,6-dialkyl-1,4-benzoquinones by molecular oxygen

“…Moreover, HPA-n with high n are more active because the time of complete DAP conversion is decreased in their presence. This may be explained by the increase in the oxidation potential of the HPA-n molecule [22]. The initial HPA-n must possess rather high oxidation potential, so that DAP can be oxidized via reaction (2) and loose, at least, four electrons according to the stoichiometry of the reaction.…”

“…That was the reason why we studied some acidic HPA-n salts as well. For acidic salts of HTPMOsO4o (HPA-4), the replacement of one proton in a HPA-n molecule by a cation (Co 2+, Mg 2+, AP +, Mn 2+, Na +) decreases the selectivity by 10-15% due to a decrease of the oxidation potential of HPA-n [22]. The optimal [HPA-n]/[DAP] ratio ranges from 5 to 7, and the selectivity to DMQ and DTQ is 75-85% and 70-77%, respectively.…”

Catalysis for Society: Towards Improved Process Efficiency in Catalytic Selective Oxidations

“…1), the conventional route using 2-methylnaphthalene and chromium oxide in sulphuric acid as the oxidant, co-produces a large amount of inorganic salts. Therefore, many efforts are aimed at developing a catalytic route, and several systems have been investigated which make use of either hydrogen peroxide [48] or O 2 [49] as the oxidant for either 2-methylnaphthalene or 2-methyl-1-naphthol. Matveev et al [49] first described the use of aqueous solutions of Keggin-type P/Mo/V polyoxometalates for the selective, stoichiometric oxidation of 2-methyl-1-naphthol, in a liquid bi-phasic system, at moderate reaction conditions (Vikasib technology).…”

Molybdenum Oxoanions as Dispersing Agents in the Preparation of Pd/C Catalysts for the Selective Oxidation of Glyoxal

“…In catalysis, it is their redox and acido-basic properties that are exploited for applications [6][7][8][9][10]. They are used for example as oxidation catalysts in liquid phase [11][12][13], with the possibility of catalyzing multi-electron redox reactions. The so-called heteropolyacids (HPAs) are used as strong inorganic acids in various catalytic processes [14,15], in solution or as solid acid catalysts [7].…”