Metal oxide catalysts comprising various dopants are provided. The catalysts are useful as heterogenous catalysts in a variety of catalytic reactions, for example, the oxidative coupling of methane to C2 hydrocarbons such as ethane and ethylene. Related methods for use and manufacture of the same are also disclosed.

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 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 method for producing a catalyst, including a slurry preparation step of preparing a slurry comprising a Mo compound, an Fe compound, a Bi compound, and an additive having a decomposition temperature of 500° C. or less; a drying step of drying the slurry to obtain a dried material; and a calcination step of calcining the dried material to obtain a calcined material, wherein the calcination step comprises a step of raising temperature of a calcination atmosphere to a predetermined temperature, and a temperature raising rate is 10° C./min or less at least at a temperature equal to or lower than the decomposition temperature of the additive.

A method for producing a catalyst, including a slurry preparation step of preparing a slurry comprising a Mo compound, an Fe compound, a Bi compound, and an additive having a decomposition temperature of 500° C. or less; a drying step of drying the slurry to obtain a dried material; and a calcination step of calcining the dried material to obtain a calcined material, wherein the calcination step comprises a step of raising temperature of a calcination atmosphere to a predetermined temperature, and a temperature raising rate is 10° C./min or less at least at a temperature equal to or lower than the decomposition temperature of the additive.

A metal oxide catalyst, which has a bulk composition represented by formula (1) below and which is used to produce a conjugated diolefin by an oxidative dehydrogenation reaction between a monoolefin, having 4 or more carbon atoms, and molecular oxygen, wherein standard deviation obtained by dividing a ratio of Bi molar concentration relative to Mo molar concentration at the surface of a catalyst particle by a ratio of the Bi molar concentration relative to the Mo molar concentration in a catalyst bulk is 0.3 or less.
Mo.sub.12Bi.sub.pFe.sub.qA.sub.aB.sub.bC.sub.cD.sub.dE.sub.eF.sub.fO.sub.x  (1)
(In the formula, A is at least one type of element selected from the group consisting of Ni and Co, B is at least one type of element selected from among alkali metal elements, C is at least one type of element selected from the group consisting of Mg, Ca, Sr, Ba, Zn and Mn, D is at least one type of rare earth element, E is at least one type of element selected from the group consisting of Cr, In and Ga, F is at least one type of element selected from the group consisting of Si, Al, Ti and Zr, O is oxygen, p, q, a, b, c, d, e, f and x denote the number of atoms of Bi, Fe, A, B, C, D, E, F and oxygen, respectively, relative to 12 Mo atoms, and are such that 0.1≤p≤5, 0.5≤q≤8, 0≤a≤10, 0.02≤b≤2, 0≤c≤5, 0≤d≤5, 0≤e≤5 and 0≤f≤200, and x is the number of oxygen atoms required to satisfy valency requirement of other elements present.)

A method for producing (meth)acrolein by vapor-phase catalytic oxidation of propylene or isobutylene in a multitubular reactor including a plurality of reaction tubes, the reaction tubes each including a reaction zone filled with a catalyst including molybdenum oxide and a cooling zone filled with an inert substance, wherein a temperature of a heat medium that flows outside the cooling zone is lower than a temperature of a heat medium that flows outside the reaction zone, and wherein the inert substance includes an inert substance having a major-axis length that is equal to or more than 1.7 times a major-axis length of the catalyst. A method for producing (meth)acrylic acid in which (meth)acrolein thus produced is converted to (meth)acrylic acid by vapor-phase catalytic oxidation.

A method for producing (meth)acrolein by vapor-phase catalytic oxidation of propylene or isobutylene in a multitubular reactor including a plurality of reaction tubes, the reaction tubes each including a reaction zone filled with a catalyst including molybdenum oxide and a cooling zone filled with an inert substance, wherein a temperature of a heat medium that flows outside the cooling zone is lower than a temperature of a heat medium that flows outside the reaction zone, and wherein the inert substance includes an inert substance having a major-axis length that is equal to or more than 1.7 times a major-axis length of the catalyst. A method for producing (meth)acrylic acid in which (meth)acrolein thus produced is converted to (meth)acrylic acid by vapor-phase catalytic oxidation.

A catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid, wherein the cumulative pore volume (A) of pores having a pore diameter of 1 μm or more and 100 μm or less, in the catalyst, is 0.12 ml/g or more and 0.19 ml/g or less, and the ratio (A/B) of the cumulative pore volume (A) to the cumulative pore volume (B) of pores having a pore diameter of 1 μm or more and 100 μm or less, in a pulverized product not passing through a Tyler 6 mesh, in a pulverized product obtained by pulverization of the catalyst under a particular condition is 0.30 or more and 0.87 or less.

A catalyst for producing unsaturated aldehyde and unsaturated carboxylic acid, wherein the cumulative pore volume (A) of pores having a pore diameter of 1 μm or more and 100 μm or less, in the catalyst, is 0.12 ml/g or more and 0.19 ml/g or less, and the ratio (A/B) of the cumulative pore volume (A) to the cumulative pore volume (B) of pores having a pore diameter of 1 μm or more and 100 μm or less, in a pulverized product not passing through a Tyler 6 mesh, in a pulverized product obtained by pulverization of the catalyst under a particular condition is 0.30 or more and 0.87 or less.