Oxidative dehydrogenation catalysts comprising MoVNbTeO having improved consistency of composition and a 25% conversion of ethylene at less than 420? C. and a selectivity to ethylene above 95% are prepared by treating the catalyst precursor with H.sub.2O.sub.2 in an amount equivalent to 0.30-2.8 mL H.sub.2O.sub.2 of a 30% solution per gram of catalyst precursor prior to calcining.

It is an object of the present invention to provide a composite oxide catalyst which can suppress the generation of CO.sub.2 and CO and improve the yield of an unsaturated nitrile in a method for subjecting propane or isobutane to a vapor-phase catalytic ammoxidation reaction to produce a corresponding unsaturated nitrile, and a method for producing the composite oxide catalyst, and a method for producing an unsaturated nitrile using the composite oxide catalyst. A composite oxide catalyst used for a vapor-phase catalytic oxidation reaction or vapor-phase catalytic ammoxidation reaction of propane or isobutane, the composite oxide catalyst comprising a composite oxide represented by the following composition formula (1):
Mo.sub.1V.sub.aSb.sub.bNb.sub.cW.sub.dZ.sub.eO.sub.n(1),
wherein the component Z is one or more element selected from the group consisting of La, Ce, Pr, Yb, Y, Sc, Sr, and Ba; a, b, c, d, e, and n represent atomic ratios of the elements; and 0.1a<0.2, 0.15b0.5, 0.01c 0.5, 0d0.4, 0e0.2, and 0.60<a/b<1.00.

It is an object of the present invention to provide a composite oxide catalyst which can suppress the generation of CO.sub.2 and CO and improve the yield of an unsaturated nitrile in a method for subjecting propane or isobutane to a vapor-phase catalytic ammoxidation reaction to produce a corresponding unsaturated nitrile, and a method for producing the composite oxide catalyst, and a method for producing an unsaturated nitrile using the composite oxide catalyst. A composite oxide catalyst used for a vapor-phase catalytic oxidation reaction or vapor-phase catalytic ammoxidation reaction of propane or isobutane, the composite oxide catalyst comprising a composite oxide represented by the following composition formula (1):
Mo.sub.1V.sub.aSb.sub.bNb.sub.cW.sub.dZ.sub.eO.sub.n(1),
wherein the component Z is one or more element selected from the group consisting of La, Ce, Pr, Yb, Y, Sc, Sr, and Ba; a, b, c, d, e, and n represent atomic ratios of the elements; and 0.1a<0.2, 0.15b0.5, 0.01c 0.5, 0d0.4, 0e0.2, and 0.60<a/b<1.00.

A supported catalyst used for synthesizing a polyether amine, and a manufacturing method of the catalyst. The catalyst comprises: a porous oxide as a support; Ni, Cu, Pd, and Rh as active components; and one or more of any of Zr, Cr, Mo, Fe, Zn, Sn, Bi, Ce, La, Hf, Sr, Sb, Mg, Be, Re, Ta, Ti, Sc, Ge and related metals as an auxiliary agent. The catalyst can be used in an amination reaction for a large molecular weight polyether polyol, and is particularly active and selective for an amination reaction of a low molecular weight polyether polyol. The catalyst has a simple and economic manufacturing technique and good potential for future applications.

A supported catalyst used for synthesizing a polyether amine, and a manufacturing method of the catalyst. The catalyst comprises: a porous oxide as a support; Ni, Cu, Pd, and Rh as active components; and one or more of any of Zr, Cr, Mo, Fe, Zn, Sn, Bi, Ce, La, Hf, Sr, Sb, Mg, Be, Re, Ta, Ti, Sc, Ge and related metals as an auxiliary agent. The catalyst can be used in an amination reaction for a large molecular weight polyether polyol, and is particularly active and selective for an amination reaction of a low molecular weight polyether polyol. The catalyst has a simple and economic manufacturing technique and good potential for future applications.

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.

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.

A catalyst for catalytic oxidation treatment of organic wastewater, comprising aluminum oxide, and nickel, ferrum, manganese, and cerium supported on the aluminum oxide in oxide form. Based on the weight of aluminum oxide, the contents of the following components in the catalyst are: nickel: 5.0-20 wt %; ferrum: 0.5-5.5 wt %; manganese: 0.5-3.5 wt %; and cerium: 1.5-3.0 wt %. The present invention has a good effect in catalytic oxidation for degrading COD organic pollutants in wastewater and has high reactivity.

A catalyst for catalytic oxidation treatment of organic wastewater, comprising aluminum oxide, and nickel, ferrum, manganese, and cerium supported on the aluminum oxide in oxide form. Based on the weight of aluminum oxide, the contents of the following components in the catalyst are: nickel: 5.0-20 wt %; ferrum: 0.5-5.5 wt %; manganese: 0.5-3.5 wt %; and cerium: 1.5-3.0 wt %. The present invention has a good effect in catalytic oxidation for degrading COD organic pollutants in wastewater and has high reactivity.

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.