| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preparing a heteropolyacid-based catalyst, which is superior in properties, life and strength and containing heteropolyacid or its salts comprising molybdophosphoric acid and/or molybdo-vanadophosphoric acid. SOLUTION: When the above heteropolyacid-based catalyst is prepared in the presence of a heteroring compound containing nitrogen, all element raw- materials constituting the catalyst and the heteroring compound containing nitrogen are mixed in thepresence of water, and a mixture which contains (1) the heteroring compound containing nitrogen, a nitric acid root and an ammonium root in which (2) the total amount of the ammonium root is less than 1.7 mole per 1 mole of the total amount of the nitric acid root and (3) the total amount of the ammonium root is less than 10 mole to 12 mole of a molybdenum atom, is prepared, and the mixture is dried and baked.
|
