Provided is a method for producing at least one of an unsaturated aldehyde and an unsaturated carboxylic acid from an alkene by an oxidation reaction, in which a n-layered catalyst layer (n≥2) is provided in a gas flow direction in a reaction tube, two or more kinds of catalysts having different activities are used; and the catalysts are packed in such a manner that dT≤20° C. is satisfied, when a difference between a temperature PT.sub.n of an exothermic peak in a n-th layer as counted from a gas inlet and a minimum value mT.sub.n−1 of a temperature of a catalyst layer which appears between an exothermic peak in a (n-1)th layer and an exothermic peak in a n-th layer from the gas inlet is represented as dT (=PT.sub.n−mT.sub.n−1), and the change rate of dT is 2.5 or less at a reaction bath temperature within a range of ±6° C. of a reaction bath temperature at which the highest yield is obtained.

Provided is a method for producing at least one of an unsaturated aldehyde and an unsaturated carboxylic acid from an alkene by an oxidation reaction, in which a n-layered catalyst layer (n≥2) is provided in a gas flow direction in a reaction tube, two or more kinds of catalysts having different activities are used; and the catalysts are packed in such a manner that dT≤20° C. is satisfied, when a difference between a temperature PT.sub.n of an exothermic peak in a n-th layer as counted from a gas inlet and a minimum value mT.sub.n−1 of a temperature of a catalyst layer which appears between an exothermic peak in a (n-1)th layer and an exothermic peak in a n-th layer from the gas inlet is represented as dT (=PT.sub.n−mT.sub.n−1), and the change rate of dT is 2.5 or less at a reaction bath temperature within a range of ±6° C. of a reaction bath temperature at which the highest yield is obtained.

Disclosed are a mesoporous composite oxide catalyst, a method for preparing the same and a method for synthesizing 1,3-butadidne using the same. The surface area is increased by introducing certain porous silica into preparation of a catalyst for synthesizing 1,3-butadiene, thereby improving a conversion ratio of normal-butene, and selectivity and yield of 1,3-butadiene, and providing economic efficiency from the viewpoint of decreasing an amount of used metal and reducing catalyst production cost.

Disclosed are a mesoporous composite oxide catalyst, a method for preparing the same and a method for synthesizing 1,3-butadidne using the same. The surface area is increased by introducing certain porous silica into preparation of a catalyst for synthesizing 1,3-butadiene, thereby improving a conversion ratio of normal-butene, and selectivity and yield of 1,3-butadiene, and providing economic efficiency from the viewpoint of decreasing an amount of used metal and reducing catalyst production cost.

Disclosed are a composite oxide catalyst for preparing butadiene and a method of preparing the same. More particularly, a composite oxide catalyst, for preparing butadiene, including a metal composite oxide and AlPO.sub.4, and a method of preparing the same are disclosed.

According to the present disclosure, a composite oxide catalyst for preparing butadiene, which includes a specific binder material, prevents generation of ingredients with a high boiling point, has superior catalyst strength, catalytic activity and butadiene yield, and a method of preparing the same are provided.

Disclosed are a composite oxide catalyst for preparing butadiene and a method of preparing the same. More particularly, a composite oxide catalyst, for preparing butadiene, including a metal composite oxide and AlPO.sub.4, and a method of preparing the same are disclosed.

According to the present disclosure, a composite oxide catalyst for preparing butadiene, which includes a specific binder material, prevents generation of ingredients with a high boiling point, has superior catalyst strength, catalytic activity and butadiene yield, and a method of preparing the same are provided.

The present invention provides a production method which is capable of stably producing a catalyst that enables a production of methacrylic acid with high selectivity. A method of producing a catalyst used for a production of methacrylic acid includes (i) preparing a slurry A1 containing a heteropolyacid containing at least phosphorus and molybdenum or a salt of the heteropolyacid containing at least phosphorus and molybdenum, (ii) preparing a slurry A2 satisfying the following Formula (I) and Formula (II) using the slurry A1, (iii) mixing the slurry A2 and a raw material liquid B containing a cationic raw material to prepare a slurry C, and (iv) drying the slurry C, α.sub.A2/α.sub.A1≤0.95 (I), 2≤D.sub.A2≤50 (II), wherein, in Formula (I), α.sub.A1 represents a half-value width (μm) of a particle size distribution of the slurry A1, α.sub.A2 represents a half-value width (μm) of a particle size distribution of the slurry A2, and in Formula (II), D.sub.A2 represents a median diameter (μm) of the particle size distribution of the slurry A2.

The present invention provides a production method which is capable of stably producing a catalyst that enables a production of methacrylic acid with high selectivity. A method of producing a catalyst used for a production of methacrylic acid includes (i) preparing a slurry A1 containing a heteropolyacid containing at least phosphorus and molybdenum or a salt of the heteropolyacid containing at least phosphorus and molybdenum, (ii) preparing a slurry A2 satisfying the following Formula (I) and Formula (II) using the slurry A1, (iii) mixing the slurry A2 and a raw material liquid B containing a cationic raw material to prepare a slurry C, and (iv) drying the slurry C, α.sub.A2/α.sub.A1≤0.95 (I), 2≤D.sub.A2≤50 (II), wherein, in Formula (I), α.sub.A1 represents a half-value width (μm) of a particle size distribution of the slurry A1, α.sub.A2 represents a half-value width (μm) of a particle size distribution of the slurry A2, and in Formula (II), D.sub.A2 represents a median diameter (μm) of the particle size distribution of the slurry A2.

Disclosed is a multi-component bismuth molybdate catalyst for production of butadiene which comprises bismuth, molybdenum and at least one metal having a monovalent, divalent or trivalent cation, and further comprises cesium and potassium and thus has advantages of improving conversion ratio, yield and selectivity of butadiene and of providing stability of process operation.

Disclosed is a multi-component bismuth molybdate catalyst for production of butadiene which comprises bismuth, molybdenum and at least one metal having a monovalent, divalent or trivalent cation, and further comprises cesium and potassium and thus has advantages of improving conversion ratio, yield and selectivity of butadiene and of providing stability of process operation.