Process for producing catalysts for the production of methacrylic acid

A method of producing a catalyst for use in the production of methacrylic acid, having a composition of the following formula (1), comprising, subjecting methacrolein to vapor phase catalytic oxidization with molecular oxygen,

• wherein, when mixing 100 parts by mass of a solution or a slurry (liquid A), containing molybdenum atoms, phosphorous atoms and vanadium atoms, in which the content of ammonium species is 0 to 1.5 mol relative to 12 mol of the molybdenum atoms, 5 to 300 parts by mass of a solution or a slurry (liquid B), containing 6 to 17 mol of ammonium species relative to 12 mol of the molybdenum atoms contained in the solution A, and a solution or a slurry (liquid C), containing an element Z, the liquid B is mixed with the liquid A, the liquid C or a mixture of the liquid A and the liquid C over a period of 0.1 to 15 minutes:
• PaMobVcCudXeYfZgOh (1 ),
• wherein P, Mo, V, Cu and O represent phosphorous, molybdenum, vanadium, copper and oxygen, respectively;
• X represents at least one element selected from the group consisting of antimony, bismuth, arsenic, germanium, zirconium, tellurium, silver, selenium, silicon, tungsten and boron;
• Y represents at least one element selected from the group consisting of iron, zinc, chromium, magnesium, tantalum, cobalt, manganese, barium, garium, cerium and lanthanum;
• Z represents at least one element selected from the group consisting of potassium, rubidium and cesium;
• a, b, c, d, e, f, g and h represent an atomic ratio of each element, and when b=12, a=0.5 to 3, c=0.01 to 3, d=0.01 to 2, e=0 to 3, f=0 to 3 and g=0.01 to 3, and h represents an atomic ratio of oxygen necessary for satisfying the valence of each of the above-mentioned components.