This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW.sub.9O.sub.34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.

This disclosure relates to photocatalytic polyoxometalate compositions of tungstovanadates and uses as water oxidation catalysts. In certain embodiments, the disclosure relates to compositions comprising water, a complex of a tetra-metal oxide cluster and VW.sub.9O.sub.34 ligands, and a photosensitizer. Typically, the metal oxide cluster is Co. In certain embodiments, the disclosure relates to electrodes and other devices comprising water oxidation catalysts disclosed herein and uses in generating fuels and electrical power from solar energy.

This document relates to oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, and iron; oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, and aluminum; and oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, iron, and aluminum.

This document relates to oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, and iron; oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, and aluminum; and oxidative dehydrogenation catalyst materials that include molybdenum, vanadium, oxygen, iron, and aluminum.

Fluidizable catalysts for the oxygen-free oxidative dehydrogenation of alkanes to corresponding olefins. The catalysts comprise 10-20% by weight per total catalyst weight of one or more vanadium oxides (VO.sub.x) such as V.sub.2O.sub.5 as well as 1-5% by weight per total catalyst weight of niobium as a promoter. The dehydrogenation catalysts are mounted on an alumina support that is modified with lanthanum to stabilize bulk phase transformation of the alumina. Various methods of preparing and characterizing the catalysts as well as methods for the oxygen-free oxidative dehydrogenation of alkanes to corresponding olefins with improved alkane conversion and olefin selectivity are also disclosed.

Fluidizable catalysts for the oxygen-free oxidative dehydrogenation of alkanes to corresponding olefins. The catalysts comprise 10-20% by weight per total catalyst weight of one or more vanadium oxides (VO.sub.x) such as V.sub.2O.sub.5 as well as 1-5% by weight per total catalyst weight of niobium as a promoter. The dehydrogenation catalysts are mounted on an alumina support that is modified with lanthanum to stabilize bulk phase transformation of the alumina. Various methods of preparing and characterizing the catalysts as well as methods for the oxygen-free oxidative dehydrogenation of alkanes to corresponding olefins with improved alkane conversion and olefin selectivity are also disclosed.

An object of the present invention is to provide a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutene, which enables a catalyst demonstrating favorable yield to be stably produced. According to the present invention, there is provided a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of: (i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively; (ii) drying the catalyst raw material mixture; and (iii) calcining a particle, in which a content of the particle having a particle diameter of 25 μm or less is 20% by mass or less and a mean particle diameter is from 35 to 70 μm, in an inert gas atmosphere.

An object of the present invention is to provide a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutene, which enables a catalyst demonstrating favorable yield to be stably produced. According to the present invention, there is provided a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of: (i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively; (ii) drying the catalyst raw material mixture; and (iii) calcining a particle, in which a content of the particle having a particle diameter of 25 μm or less is 20% by mass or less and a mean particle diameter is from 35 to 70 μm, in an inert gas atmosphere.

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.