초록 ▼

A heteropolyacid type catalyst capable of producing methacrylic acid from methacrolein and molecular oxygen at an extremely high yield for a long time at a relatively low temperature for a short contacting time under a vapor phase is provided. This catalyst is prepared by: (a) mixing molybdophosphor

A heteropolyacid type catalyst capable of producing methacrylic acid from methacrolein and molecular oxygen at an extremely high yield for a long time at a relatively low temperature for a short contacting time under a vapor phase is provided. This catalyst is prepared by: (a) mixing molybdophosphoric acid and compounds containing the other constituent elements of the catalyst with each other in the presence of water; (b) concentrating or drying the resultant solution or slurry; (c) adjusting the water content of the resultant concentrated or dried mixture to 5% to 20% by weight; and (d) heat treating the mixture at a temperature of 100°C. to 300°C.

대표청구항 ▼

A method for preparing a heteropolyacid type catalyst containing, as catalyst constituent elements, phosphorus, molybdenum, copper, and arsenic and suitable for use in the production of methacrylic acid from methacrolein and molecular oxygen at an elevated temperature under a vapor phase, comprising

A method for preparing a heteropolyacid type catalyst containing, as catalyst constituent elements, phosphorus, molybdenum, copper, and arsenic and suitable for use in the production of methacrylic acid from methacrolein and molecular oxygen at an elevated temperature under a vapor phase, comprising the steps of: (a) mixing molybdophosphoric acid and compounds containing the other constituent elements of the catalyst in the presence of water; (b) concentrating or drying the resultant solution or slurry; (c) adjusting the water content of the resultant concentrated or dried mixture to 5% to 20% by weight; and (d) heat treating the mixture at a temperature of 100°C. to 300°C.