Provided are a catalyst that may suppress the production of a coke-like substance in a reaction for producing a conjugated diolefin from a mixed gas including a monoolefin having 4 or more carbon atoms and molecular oxygen. A composite metal oxide catalyst for producing a conjugated diolefin from a mixed gas including a monoolefin having 4 or more carbon atoms and molecular oxygen by a catalytic oxidative dehydrogenation reaction, the composite metal oxide catalyst having a relative intensity range of X-ray diffraction peaks represented by the following Formula (A): 0Rh(=Ph1/Ph2)<0.8 (A) wherein Ph1 represents the maximum peak height within the range of 2=28.10.2 for the X-ray diffraction peaks; Ph2 represents the maximum peak height within the range of 2=27.90.2 for the X-ray diffraction peaks; and Rh represents the relative intensity ratio of Ph1 with respect to Ph2.

A method for producing diene in which diene can be produced in a high yield by using a raw material including a branched olefin and a straight chain olefin is provided. The method for producing diene comprises: a step 1 of obtaining an internal olefin by removing a branched olefin from a raw material including at least the branched olefin and a straight chain olefin; a step 2 of isomerizing the internal olefin to a terminal olefin by using an isomerization catalyst; and a step 3 of producing diene from the terminal olefin obtained in the step 2 by oxidative dehydrogenation using a dehydrogenation catalyst.

Provided is a method for producing an unsaturated aldehyde including subjecting an alkene to partial oxidation using a fixed bed multi-tube reactor to produce the corresponding unsaturated aldehyde, in which n catalyst layers (n is 2 or more) in a gas flow direction in a reaction tube are provided, when a filling length of the catalyst layers from a first catalyst layer to an (n1)th catalyst layer from a gas inlet side of the reaction tube is L, and a filling length of an nth catalyst layer from the gas inlet side of the reaction tube is Ln, a relationship between L and Ln satisfies the following equation (1): $\begin{array}{cc}1<L\text{/}\mathrm{Ln}3,& \left(1\right)\end{array}$
and a composition of a catalytically active component contained in the catalyst layers from the first catalyst layer to the (n1)th layer from the gas inlet side of the reaction tube is different from a composition of a catalytically active component contained in the nth catalyst layer from the gas inlet side of the reaction tube.

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.

Provided are a catalyst which, in a reaction. for producing a conjugated diolefin by catalytic oxidative dehydrogenation from a mixed gas including a monoolefin having 4 or more carbon atoms and molecular oxygen, may suppress the production of a coke-like substance and improve the long-term stability of the reaction; and a method for producing the same. Disclosed is a composite metal oxide catalyst for producing a conjugated diolefin by a gas phase catalytic oxidative dehydrogenation reaction from a mixed gas including a monoolefin having 4 or more carbon atoms and molecular oxygen, the composite metal oxide catalyst having a solid acidity of 35 to 172 mol/g.

The present invention relates to a method of preparing butadiene. More particularly, the present invention relates to a method of preparing butadiene by feeding butene and oxygen into a reactor containing a composite metal oxide catalyst and performing oxidative dehydrogenation, wherein a mole ratio of the oxygen to the butene is 1.8 to 2.2. In accordance with the present invention, a method of preparing butadiene to secure long-term operation stability by maintaining the intensity of a catalyst despite oxidative dehydrogenation and not to decrease selectivity due to less side reaction is provided.

A hollow cylindrical shaped catalyst body for gas phase oxidation of an alkene to an ,-unsaturated aldehyde and/or an ,-unsaturated carboxylic acid comprises a compacted multimetal oxide having an external diameter ED, an internal diameter ID and a height H, wherein ED is in the range from 3.5 to 4.5 mm; the ratio q=ID/ED is in the range from 0.4 to 0.55; and the ratio p=H/ED is in the range from 0.5 to 1. The shaped catalyst body is mechanically stable and catalyzes the partial oxidation of an alkene to the products of value with high selectivity. It provides a sufficiently high catalyst mass density of the catalyst bed and good long-term stability with acceptable pressure drop.

An ammoxidation catalyst includes a metal oxide represented by Chemical Formula 1 supported on a silica carrier, wherein the catalyst has pores having a diameter of 5 to 200 nm, a pore volume of 0.1 to 3.0 cm.sup.3/g, and a BET surface area of 50 m2/g to 1,000 m2/g:
Mo.sub.12Bi.sub.aFe.sub.bA.sub.cB.sub.dC.sub.eO.sub.xChemical Formula 1 wherein in Chemical Formula 1, A is one or more elements of Ni, Mn, Co, Zn, Mg, Ca, and Ba, B is one or more elements of Li, Na, K, Rb, and Cs, C is one or more elements of Cr, W, B, Al, Ca, and V, and a to e, and x are respectively fractions of each atom or atomic group, wherein a is 0.1 to 5, b is 0.1 to 5, c is 0.1 to 10, d is 0.1 to 2, e is 0 to 10, and x is 24 to 48.

Provided is a catalyst having high activity and yield of a target product for producing an unsaturated aldehyde and/or an unsaturated carboxylic acid and further having high mechanical strength. The catalyst is a catalyst prepared by a method in which a catalyst formulation satisfies specified atomic ratios; and in the preparation thereof, a molybdenum component raw material is an ammonium molybdate, a solvent for dissolving the ammonium molybdate is water, a bismuth component raw material is bismuth nitrate, and a solvent for dissolving bismuth nitrate is a nitric acid aqueous solution, and the weight of water for dissolving the ammonium molybdate, the weight of the nitric acid aqueous solution for dissolving the bismuth nitrate, and the acid concentration of the nitric acid aqueous solution are satisfied with specified ranges, respectively.

A catalyst for producing butadiene using n-butene as a raw material, a process for producing the same and a process for producing butadiene using the catalyst are provided, and specifically, a catalyst for producing butadiene by gas-phase contact oxidative dehydrogenation of n-butene, which is capable of stably producing butadiene in a high yield from the beginning of the reaction, a process for producing the same and a process for producing butadiene, in which the catalyst is a shaped catalyst containing a complex metal oxide having molybdenum as an essential ingredient, wherein the pore volume of macropores is 80% or more, more preferably 90% or more, based on the total pore volume, are provided.