Heterogeneous metal oxide catalysts are widely studied for the aerobic oxidations of C1–C4 alkanes to form olefins and oxygenates. In this review, we outline the properties of supported metal oxides, mixed-metal oxides, and zeolites and detail their most common applications as catalysts for partial oxidations of light alkanes. By doing this we establish similarities between different classes of metal oxides and identify common themes in reaction mechanisms and research strategies for catalyst improvement. For example, almost all partial alkane oxidations, regardless of the metal oxide, follow Mars–van Krevelen reaction kinetics, which utilize lattice oxygen atoms to reoxidize the reduced metal centers while the gaseous O2 reactant replenishes these lattice oxygen vacancies. Many of the most-promising metal oxide catalysts include V5+ surface species as a necessary constituent to convert the alkane. Transformations involving sequential oxidation steps (i.e., propane to acrylic acid) require specific reacti...

Aerobic Oxidations of Light Alkanes over Solid Metal Oxide Catalysts

The present invention relates to processes for purifying a composition containing (meth)acrylic acid, at least one impurity and water, wherein the composition has a water content in the range of 0.55 to 90, based on the composition, to form a purified phase containing (meth)acrylic acid and at least one impurity, wherein, in the purified phase, the quantity of at least one impurity is less than 7% by weight, based on (meth)acrylic acid in the purified phase.

meth)acrylic acid crystal and method for the production and purification of aqueous (meth)acrylic acid

A catalyst comprising a promoted mixed metal oxide is useful for the vapor phase oxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated carboxylic acid and for the vapor phase ammoxidation of an alkane or a mixture of an alkane and an alkene to an unsaturated nitrile.

Promoted multi-metal oxide catalyst

A process for the catalytic gas-phase oxidation of propene to acrylic acid, in which the reaction gas starting mixture is oxidized, with a high propene loading, in a first reaction stage, over a first fixed-bed catalyst which is housed in two successive reaction zones A, B, the reaction zone B being kept at a higher temperature than the reaction zone A, and the acrolein-containing product gas mixture of the first reaction stage is then oxidized in a second reaction stage, with a high acrolein loading, over a second fixed-bed catalyst which is housed in two successive reaction zones C, D, the reaction zone D being kept at a higher temperature than the reaction zone C.

Method for the catalytic gas phase oxidation of propene into acrylic acid

The invention relates to a method for producing acrolein and/or acrylic acid from propane and/or propene, comprising the following steps: (a) separating the propane and/or propene from a gas mixture containing propane or propene by means of absorption into an absorption agent, (b) separating the propane and/or propene from the absorption agent thereby obtaining a gas B, and (c) using the gas B obtained in step (b) to convert propane and/or propene into acrolein and/or acrylic acid by means of oxidation. No heterogeneously catalysed dehydrogenation of propane is carried out between steps (b) and (c) without a supply of oxygen.

Method for producing acrolein and/or acrylic acid

A method for producing an unsaturated carboxylic acid, which comprises subjecting an alkane to a vapor phase catalytic oxidation reaction in the presence of a catalyst containing a mixed metal oxide comprising, as essential components, Mo, V, Te, O and X wherein X is at least one element selected from the group consisting of niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron, indium and cerium, wherein the proportions of the respective essential components, based on the total amount of the essential components exclusive of oxygen, satisfy the following formulas: 0.25<r.sub.Mo <0.98 0.003<r.sub.V <0.5 0.003<r.sub.Te <0.5 0.003<r.sub.X <0.5 wherein r Mo , r V , r Te and r X are molar fractions of Mo, V, Te and X, respectively, based on the total amount of the essential components exclusive of oxygen.

Method for producing an unsaturated carboxylic acid

PURPOSE:To produce an alpha, beta-unsaturated carboxylic acid in high yield by adding steam to a raw material gas in catalytically oxidizing an aliphatic saturated hydrocarbon in vapor phase in the presence of a compound metal oxide catalyst. CONSTITUTION:In producing an alpha, beta-unsaturated carboxylic acid by catalytically oxidinzing a 3-8C aliphatic saturated hydrocarbon in a vapor phase in the presence of a compound metal oxide catalyst, a gas comprising an aliphatic saturated hydrocarbon, steam and an oxygen-containing gas in the molar ratio of hydrocarbon:oxygen:a diluting gas:H2O=1:(0.1-10.0):0-20:(0.2-70) is used as a raw material gas and one or more of (i) Mo, V, Te, >=1 kind metal selected from among X and oxygen, (ii) Bi, No, >=1 kind metal selected from among X and oxygen, (iii) V, >=1 kind metal selected from among X and oxygen and (ir)Fe, >=1 kind metal selected from among X and oxygen as essential components are used as the compound metal oxide catalyst. Especially the component (i) is preferable. X :Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rk, Ni, Pd, Pt, Sb, Bi, B, In, Cs;X : V, Nb, Tl, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Sb, P, B, Pb, Ga, In, Ce, Li, Na, K, Rb, Cs, Tl, Cu, Ag; X : Fe, Sb, P, Li, Na, K, Rb, Cs, W, Ti, Al, Zr, Sn, Ge, In; X : Sb, P, Cr, Ti, Mo, Al, Zr, Sn, Ge, In.

Production of alpha, beta-unsaturated carboxylic acid

PURPOSE:To produce acrylic acid in high yield by one-stage method by using propylene as a raw material. CONSTITUTION:Propylene is subjected to vapor-phase catalytic oxidation reaction in the presence of a catalyst of a compound metal oxide comprising Mo, V, Te, X and O as essential components (X is one or more elements selected from niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, palladium, platinum, antimony, bismuth, boron, indium, lithium, sodium, potassium, rubidium, cesium and cerium) in a given ratio of existence of each essential component based on the sum of the essential components except oxygen (e.g. Mo1V0.3Te0.23Nb0.12 On) to produce acrylic acid.

Production of acrylic acid

PROBLEM TO BE SOLVED: To obtain ethylene in a high selectively and in a high yield without using an expensive element and without adding a halogen, etc., to the reaction system, by bringing ethane into contact with a molecular oxygen-containing gas in the presence of a catalyst containing a specific composite metal oxide at a high temperature. SOLUTION: This method for producing ethylene comprises bringing ethane into contact with a molecular oxygen-containing gas at a temperature of 250-500 deg.C in the presence of a catalyst containing a composite metal oxide containing Mo, V and Sb as essential components and having a powder X-ray diffraction mainly having a characteristic pattern of the table. The composite metal oxide is obtained by adding a Mo-containing compound and a compound containing an element such as Ti or Zr to an aqueous solution containing a V-containing component and a Sb-containing component, drying the aqueous solution and subsequently calcining the obtained catalyst precursor.

Production of ethylene

PROBLEM TO BE SOLVED: To obtain a catalyst excellent in characteristics such as selectivity and activity in a condition of a low temp. by hydrothermally treating a raw material mixture containing Mo, V, Te, Sb in a specific temp. range. SOLUTION: This water based mixture containing each raw material of Mo, V, Te, Sb is hydrothermally treated at 100-350 deg.C to obtain a multiple metal oxide expressed by Mo1.0VaTebSbα-bXx(NH4)yOz. In the formula, X represents >=1 kinds of elements selected from Ti, Zr, Nb, Ta, Cr, W, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Zn, In, Sn, Pb, Bi and Ce, 0.01<=a<=1.0, 0<=b<=α, 0<=x<=1.0, 0.01<=α/(1+a+x)<=0.05, 0<=y<=(1+a+x) and (n) is fixed by the oxidizing state of other elements. Each raw material exists in the dispersed or dissolved state in water before the reaction and is necessarily heated in the reaction vessel. At least a part of the raw materials is preferably soluble in water.

Yukio Koyasu

Papers

Method for producing an unsaturated carboxylic acid

Production of alpha, beta-unsaturated carboxylic acid

Production of acrylic acid

Production of ethylene

Production of multiple metal oxide