Patent ID: 7425519

Claim:
A method of reducing a tungsten species leaching which is carried out by liquid-phase oxidation reaction using a tungsten species, wherein that, in carrying out said method of liquid-phase oxidation reaction using a catalyst comprising a tungsten species as an essential component, wherein said catalyst is obtained by causing said tungsten species to be supported on a porous support and, further separately causing a third element other than the component elements of said porous support and the tungsten element to be present in said catalyst as a component different from said tungsten species or the porous support; wherein said third element comprises at least one element selected from the group consisting of the elements of the groups 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 and 17 of the periodic table, and wherein a reactant substrate is selected from the group consisting of cyclohexanone, cyclobutanone, unsaturated hydrocarbons having 2 to 15 carbon atoms, a compound having at least one ethylenic double bond and a group selected from —COOH, —CN, —COOR and —OR, wherein R being an alkyl, cycloalkyl, aryl or allylalkyl substituent; or an aryl, allylalkyl, halogen, nitro, sulfo, carbonyl, hydroxyl or ether group, an oxidizing agent used is selected from molecular oxygen, hydrogen peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, peracetic acid, oxygen-hydrogen mixed gases, dinitrogen monoxide, and iodosylbenzene, a reaction temperature is not lower than room temperature, but not higher than 250° C., and a reaction pressure is not lower than ordinary pressure but not higher than 2×10 7 Pa, and wherein the reaction is selected from aldehyde formation from a primary alcohol having 2 to 15 carbon atoms, carboxylic acid formation from an aldehyde having 2 to 15 carbon atoms, and ketone formation from a secondary alcohol having 2 to 15 carbon atoms if the liquid-phase oxidation reaction is hydroxyl group oxidation.