The present invention provides a method for producing a catalyst for ammoxidation, comprising steps of: preparing a catalyst precursor slurry comprising a liquid phase and a solid phase; drying the catalyst precursor slurry to obtain dry a particle; and calcining the dry particle to obtain a catalyst for ammoxidation, wherein the solid phase of the catalyst precursor slurry comprises an aggregate containing a metal and a carrier, metal primary particles constituting the aggregate have a particle size of 1 μm or smaller, and an average particle size of the metal primary particles is 40 nm or larger and 200 nm or smaller.

The present invention provides a method for producing a catalyst for ammoxidation, comprising steps of: preparing a catalyst precursor slurry comprising a liquid phase and a solid phase; drying the catalyst precursor slurry to obtain dry a particle; and calcining the dry particle to obtain a catalyst for ammoxidation, wherein the solid phase of the catalyst precursor slurry comprises an aggregate containing a metal and a carrier, metal primary particles constituting the aggregate have a particle size of 1 μm or smaller, and an average particle size of the metal primary particles is 40 nm or larger and 200 nm or smaller.

The present disclosure provides methods for fabricating catalysts for ammonia decomposition. The method may comprise (a) subjecting a catalyst support to one or more physical or chemical processes to optimize one or more pores, morphologies, and/or surface chemistry or property of the catalyst support; (b) depositing a composite support material on the catalyst support, wherein the composite support material comprises a morphology or surface chemistry or property; and (c) depositing one or more active metals on at least one of the composite support material and the catalyst support, wherein the one or more active metals comprise one or more nanoparticles configured to conform to the morphology of the composite support material and/or catalyst support material, thereby optimizing one or more active sites on the nanoparticles for ammonia processing.

The present disclosure provides methods for fabricating catalysts for ammonia decomposition. The method may comprise (a) subjecting a catalyst support to one or more physical or chemical processes to optimize one or more pores, morphologies, and/or surface chemistry or property of the catalyst support; (b) depositing a composite support material on the catalyst support, wherein the composite support material comprises a morphology or surface chemistry or property; and (c) depositing one or more active metals on at least one of the composite support material and the catalyst support, wherein the one or more active metals comprise one or more nanoparticles configured to conform to the morphology of the composite support material and/or catalyst support material, thereby optimizing one or more active sites on the nanoparticles for ammonia processing.

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.

A method for producing a conjugated diolefin is configured as follows. A monoolefin having four or more carbon atoms is fed from a plurality of monoolefin feed nozzles. In addition, at least 50% or more of a total amount of an oxygen-containing gas is fed from an oxygen-containing gas feed nozzle located at a bottom of a fluidized bed reactor. Furthermore, the plurality of monoolefin feed nozzles at n places located at heights a1, a2, . . . , and an from the oxygen-containing gas feed nozzle, respectively, feed the monoolefin having four or more carbon atoms at ratios of b1, b2, . . . , bn (b1+b2+ . . . +bn=1), respectively. Furthermore, a weighted mean value represented by the following formula is 100 mm or greater:
weighted mean value=a1*b1+a2*b2+ . . . +an*bn.

A method for producing a conjugated diolefin is configured as follows. A monoolefin having four or more carbon atoms is fed from a plurality of monoolefin feed nozzles. In addition, at least 50% or more of a total amount of an oxygen-containing gas is fed from an oxygen-containing gas feed nozzle located at a bottom of a fluidized bed reactor. Furthermore, the plurality of monoolefin feed nozzles at n places located at heights a1, a2, . . . , and an from the oxygen-containing gas feed nozzle, respectively, feed the monoolefin having four or more carbon atoms at ratios of b1, b2, . . . , bn (b1+b2+ . . . +bn=1), respectively. Furthermore, a weighted mean value represented by the following formula is 100 mm or greater:
weighted mean value=a1*b1+a2*b2+ . . . +an*bn.

A catalyst comprising molybdenum, bismuth, iron, and nickel, wherein a proportion of a surface concentration of the nickel to a bulk concentration of the nickel is 0.60 to 1.20.

A catalyst comprising molybdenum, bismuth, iron, and nickel, wherein a proportion of a surface concentration of the nickel to a bulk concentration of the nickel is 0.60 to 1.20.