Catalyst, method for producing catalyst, and method for producing acrylonitrile
The present invention provides a catalyst including Mo, Bi, and Fe, wherein P/R is 0.10 or less, wherein P is a peak intensity at 2θ=22.9±0.2° and R is a peak intensity at 2θ=26.6±0.2°, in X-ray diffraction analysis.
1. A catalyst comprising Mo, Bi, and Fe, wherein:
P/R is 0.10 or less, wherein P is a peak intensity at 2θ=22.9±0.2° and R is a peak intensity at 2θ=26.6±0.2°, in X-ray diffraction analysis.
2. The catalyst according to claim 1 , comprising Mo, Bi, and Fe, wherein:
Q/R is 0.06 or more, wherein Q is a peak intensity at 2θ=28.0±0.1° and R is a peak intensity at 2θ=26.6±0.2°, in X-ray diffraction analysis.
3. The catalyst according to claim 1 , wherein the catalyst is represented by formula (1):
Mo 12 Bi a Fe b X c Y d Z e O f (1)
wherein, X represents at least one element selected from the group consisting of nickel, cobalt, magnesium, calcium, zinc, strontium, barium, and tungsten;
Y represents at least one element selected from the group consisting of cerium, chromium, lanthanum, neodymium, yttrium, praseodymium, samarium, aluminum, boron, gallium, and indium;
Z represents at least one element selected from the group consisting of sodium, potassium, rubidium, and cesium;
a, b, c, d, and e satisfy 0.1≤a≤2.0, 0.1≤b≤4.0, 0.1≤c≤10.0, 0.1≤d≤3.0, and 0.01≤e≤2.0, respectively; and
f represents a number of oxygen atom needed to satisfy an atomic valence requirement of element existing other than oxygen.
4. The catalyst according to claim 3 , wherein a satisfies 0.1≤a≤0.7.
5. The catalyst according to claim 1 , wherein the catalyst further comprises silica.
6. A method for producing the catalyst according to claim 1 , comprising:
a step of spray-drying a slurry comprising Mo, Bi, and Fe to obtain a dried particle; and
a step of calcining the dried particle in air and further treating in the presence of a gas that comprises oxygen and ammonia and has 0.1 to 9% by volume of water content.
7. A method for producing the catalyst according to claim 1 , comprising:
a step of spray-drying a slurry comprising Mo, Bi, and Fe to obtain a dried particle; and
a step of calcining the dried particle in air and further treating in the presence of a reducing gas and oxygen.
8. The method for producing the catalyst according to claim 7 , wherein an amount of oxygen with respect to the reducing gas (a ratio of oxygen/reducing gas) is 0.3 to 0.95 times a stoichiometric ratio at which the reducing gas is completely combusted.
9. A method for producing acrylonitrile comprising a step of reacting propylene, molecular oxygen, and ammonia with each other in the presence of the catalyst according to claim 1 .
10. The method for producing acrylonitrile according to claim 9 , wherein the method is carried out by a fluidized bed reactor.
11. The method for producing acrylonitrile according to claim 9 , wherein a molar ratio of ammonia and air to propylene is in a range of 1.0/(0.8 to 2.5)/(7.0 to 12.0) represented by a ratio of propylene/ammonia/air.
12. The method for producing acrylonitrile according to claim 9 , wherein a reaction is carried out in a temperature range of 300 to 550° C.