Abstract: A method for manufacturing a catalyst of which active components are partly neutralized salt of heteropoly acid comprising molybdenum, phosphorus, vanadium, cesium, antimony, and ammonia as essential components, wherein the method is characterized in mixing an antimony compound with a complex oxide of the essential active components in the catalyst containing active components other than antimony, wherein the antimony compound may be added during slurry preparation.

Abstract: The present invention relates to a method for manufacturing a regenerated catalyst from a recovered catalyst from manufacturing process or a used catalyst of a heteropoly acid-based catalyst containing molybdenum, phosphorus, vanadium or copper as an essential component by the below-described Process a to Process f: Process a: a solution A is prepared by mixing a substance M with an aqueous solvent and removing a component insoluble in the solvent; Process b: the molar quantity of at least one component of molybdenum, phosphorus, vanadium or copper contained in the solution A is measured; Process c: an aqueous hydrogen peroxide solution is added to the solution A to obtain a solution B; Process d: the difference between the content obtained in Process b and the theoretical value of a required element is determined and the shortage amount of the catalyst component is added to the solution B to prepare a solution C; Process e: the solution C is dried to prepare catalyst granules D; and Process f: the catalyst

Abstract: It is an object of the present invention to provide a catalyst having excellent performance and high mechanical strength for use in the production of methacrylic acid. A method for manufacturing a catalyst comprising essential active components of molybdenum, phosphorus, vanadium, cesium, ammonia, copper, and antimony for use in the production of methacrylic acid, comprising drying a slurry prepared by mixing a compound(s) containing the essential active components with water and then calcining the resulting dry powder and molding the calcined powder.

Abstract: The present invention relates to a method for producing methacrolein and/or methacrylic acid characterized in that the catalyst filling length of a dehydration catalyst layer is 3 to 20% of the catalyst filling length of an oxidation catalyst layer in a method where raw material gas containing gaseous t-butanol is supplied to a fixed-bed multitubular reactor having a dehydration catalyst layer and an oxidation catalyst layer in this order, from the entrance for raw material gas toward the exit, to produce methacrolein and/or methacrylic acid by dehydration reaction and catalytic gas phase oxidation reaction, and the present invention can increase the conventional yield of approximately 80% to 81 to 82% even when a reaction bath temperature is relatively low (approximately 355° C.).

Abstract: It is an object of the present invention to provide a catalyst having excellent performance and high mechanical strength for use in the production of methacrylic acid. A method for manufacturing a catalyst comprising essential active components of molybdenum, phosphorus, vanadium, cesium, ammonia, copper, and antimony for use in the production of methacrylic acid, comprising drying a slurry prepared by mixing a compound(s) containing the essential active components with water and then calcining the resulting dry powder and molding the calcined powder.

Abstract: It is an object of the present invention to provide a catalyst having excellent performance and high mechanical strength for use in the production of methacrylic acid. A method for manufacturing a catalyst comprising essential active components of molybdenum, phosphorus, vanadium, cesium, ammonia, copper, and antimony for use in the production of methacrylic acid, comprising drying a slurry prepared by mixing a compound(s) containing the essential active components with water and then calcining the resulting dry powder and molding the calcined powder.

Abstract: It is an object to provide a simple method for producing catalysts available in various reaction conditions, that allow gas-phase catalytic oxidation of methacrolein and the like to give methacrylic acid with high yield, high selectivity and stable methacrylic yield over extended time. A method for manufacturing a catalyst of which active components are partly neutralized salt of heteropoly acid comprising molybdenum, phosphorus, vanadium, cesium, antimony, and ammonia as essential components, wherein the method is characterized in mixing an antimony compound with a complex oxide of the essential active components in the catalyst containing active components other than antimony. The antimony compound may be added during slurry preparation.

Abstract: The present invention relates to a method for producing methacrolein and/or methacrylic acid characterized in that the catalyst filling length of a dehydration catalyst layer is 3 to 20% of the catalyst filling length of an oxidation catalyst layer in a method where raw material gas containing gaseous t-butanol is supplied to a fixed-bed multitubular reactor having a dehydration catalyst layer and an oxidation catalyst layer in this order, from the entrance for raw material gas toward the exit, to produce methacrolein and/or methacrylic acid by dehydration reaction and catalytic gas phase oxidation reaction, and the present invention can increase the conventional yield of approximately 80% to 81 to 82% even when a reaction bath temperature is relatively low (approximately 355° C.).

Abstract: It is an object of the present invention to provide a catalyst having excellent performance and high mechanical strength for use in the production of methacrylic acid. A method for manufacturing a catalyst comprising essential active components of molybdenum, phosphorus, vanadium, cesium, ammonia, copper, and antimony for use in the production of methacrylic acid, comprising drying a slurry prepared by mixing a compound(s) containing the essential active components with water and then calcining the resulting dry powder and molding the calcined powder.

Abstract: A catalyst having a high activity and mechanical strength and a process for preparing it are provided. The catalyst comprises molybdenum, vanadium, copper and antimony as essential components. The peak in X-ray diffractometry of the catalytically active component with Cu--K.alpha. line is largest at 22.2.+-.0.30.degree. (2.theta.).

Abstract: A catalyst comprising (1) palladium, (2) phosphorus, (3) antimony, (4) X and (5) oxygen wherein X denotes at least one element selected from the group consisting of potassium, sodium, rubidium, lithium, cerium, beryllium, magnesium, calcium, vanadium, strontium, zinc, thorium and rhenium.There is also provided a process for the manufacture of methacrylic or acrylic acid by oxidizing methacrolein or acrolein with molecular oxygen in the vapor phase in the presence of the catalyst defined above.

Abstract: Methacrolein or acrolein is oxidized with molecular oxygen in the presence of water vapor, a catalyst containing palladium, phosphorus, antimony(optionally) and oxygen and a phosphoric acid or a compound capable of forming phosphoric acid during the reaction.

Abstract: A catalyst comprising (1) palladium, (2) phosphorus, (3) antimony, (4) X and (5) oxygen wherein X denotes at least one element selected from the group consisting of potassium, sodium, rubidium, lithium, cerium, beryllium, magnesium, calcium, vanadium, strontium, zinc, thorium and rhenium.There is also provided a process for the manufacture of methacrylic or acrylic acid by oxidizing methacrolein or acrolein with molecular oxygen in the vapor phase in the presence of the catalyst defined above.

Abstract: Methacrylic acid and its ester or acrylic acid and its ester are prepared at the same time by reacting methacrolein or acrolein with an aliphatic alcohol and molecular oxygen in vapor phase in the presence of a Pd-- P--P-- O or Pd-- P-- Sb-- O catalyst.