The present invention relates to a catalyst for the dehydrogenation of hydrocarbons which is based on iron oxide and a process for producing it. The catalyst comprises at least one iron compound, at least one potassium compound and from 11 to 24% by weight of at least one cerium compound, calculated as CeO.sub.2, wherein the at least one iron compound and the at least one potassium compound are at least partly present in the form of one or more K/Fe mixed oxide phases of the general formula K.sub.xFe.sub.yO.sub.z, where x is from 1 to 17; y is from 1 to 22 and z is from 2 to 34, and comprises at least 50% by weight, based on the total catalyst, of the K/Fe mixed oxide phases, and also a process for producing it.

An object of the present invention is to provide a method for production of a high purity conjugated diolefin. The method for production of a conjugated diolefin of the present invention comprises steps of supplying a source gas containing a C4 or higher monoolefin and an oxygen-containing gas into a reactor, bringing a catalyst into contact with the gas mixture, compressing a gas containing a conjugated diolefin produced by an oxidative dehydrogenation reaction to obtain a liquefied gas and rinsing the liquefied gas with water.

The invention discloses a binder-free high strength and low steam-to-oil ratio ethylbenzene dehydrogenation catalyst, which is characterized by comprising the following components in percentage by weight: (a) 60-85% Fe.sub.2O.sub.3; (b) 3-25% K.sub.2O; (c) 0.1-5% MoO.sub.3; (d) 3-20% CeO.sub.2; (e) 0.1-5% CaO; (f) 0.1-5% Na.sub.2O; (g) 0.1-5% MnO.sub.2, wherein the weight ratio of sodium oxide to manganese dioxide is 0.1-10, and no binder is added during the preparation of the catalyst. The low steam-to-oil ratio ethylbenzene dehydrogenation catalyst provided by the present invention contains no binder and maintains high strength, and has high activity and stability at low steam-to-oil ratio.

3D bundle-shaped multi-walled carbon nanotubes and preparation method, includes the following steps: uniformly mixing bi-component alloy catalyst and transition metal in an inert gas environment in order to obtain a three-component nano-intermetallic alloy catalyst; disposing the intermetallic catalyst on the substrate; allowing hydrogen to flow through the substrate, and heating the substrate to a first temperature, and using the hydrogen to undergo a reduction of the intermetallic catalyst at the first temperature; applying a protective gas and a carbon source gas, heating the substrate to a second temperature, undergoing a reaction at the second temperature to generate the 3D bundle-shaped multi-walled carbon nanotubes, and collecting the 3D bundle-shaped multi-walled carbon nanotubes after annealing; wherein the second temperature is greater than or equal to the first temperature; a working electrode includes conductive drain material, a conductive bonding gent and a plurality of 3D bundle-shaped multi-walled carbon nanotubes.

Catalyst comprising an active phase based on at least one group VIB metal, at least one group VIII metal, phosphorus, sodium and an alumina-based support, the sodium content being between 50 and 2000 ppm by weight in the form of NaO relative to the total weight of said catalyst, and the molar ratio of phosphorus to sodium being between 1.5 and 300.

Provided is a catalyst for manufacturing an unsaturated aldehyde and/or an unsaturated carboxylic acid, which is prepared by a method in which a molybdenum component raw material is composed of only an ammonium molybdate, the weight of water for dissolution is 8.5 times or less relative to the weight of molybdenum contained in the ammonium molybdate; and a bismuth component raw material is composed of only bismuth nitrate, the weight of a nitric acid aqueous solution for dissolution is 2.3 times or more relative to the weight of bismuth contained in the bismuth nitrate, and a nitric acid concentration in the nitric acid aqueous solution for dissolving the bismuth nitrate is 10% by weight or more.

A method for producing an ammoxidation catalyst, the method including: a step (i) of preparing a starting material slurry comprising molybdenum, bismuth, iron, and a carboxylic acid compound; a step (ii) of stirring the starting material slurry in a temperature range of 30 to 50 C. for 20 minutes to 8 hours, thereby preparing a precursor slurry; a step of spray-drying the precursor slurry, thereby obtaining a dried particle; and a step of calcining the dried particle.

A sulfur-tolerant catalyst can be used in the sulfur-tolerant shift catalytic reaction. The catalyst has a carrier and a molybdenum oxide, a cobalt oxide and a cobalt-molybdenum-based perovskite composite oxide carried thereon. The cobalt-molybdenum-based perovskite composite oxide contains a molybdenum element, a cobalt element, an A element, and an oxygen element. The A element is one or more selected from a group consisting of a rare-earth metal element, an alkali metal element and an alkaline earth metal element.

A catalyst precursor represented by the following formula (1) having an average particle diameter (D50), which is a particle diameter at which a cumulative volume fraction is 50%, of 10 ?m or more and 40 ?m or less.

Mo.sub.a1Bi.sub.b1Ni.sub.c1Co.sub.d1Fe.sub.e1X.sub.f1Y.sub.g1Z.sub.h1O.sub.i1(1) where, Mo, Bi, Ni, Co and Fe represent molybdenum, bismuth, nickel, cobalt, and iron, respectively; X is tungsten or the like; Y is potassium or the like; and Z belongs to the 1st to 16th groups in the periodic table and represents at least one element selected from elements other than the above Mo, Bi, Ni, Co, Fe, X, and Y.

Provided are a catalyst that suppresses production of a coke-like material and improves the long-term stability of the reaction, and a method for producing the catalyst. A composite metal oxide catalyst for conjugated diolefin production is used 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 catalyst having a relative intensity ratio of X-ray diffraction peaks represented by the following Formula (A):

0.9<Pr<3.0

Pr=Pi1/Pi2(A) (in the formula, Pi1 represents the maximum peak height at a 2 value in the range of 26.40.3 in the X-ray diffraction peaks; Pi2 represents the maximum peak height at a 2 value in the range of 28.50.3 in the X-ray diffraction peaks; and Pr represents the relative intensity ratio of Pi1 with respect to Pi2).