Catalyst for partial oxidation and preparation method thereof
The present invention relates to a catalyst for partial oxidation and a preparation method thereof, more particularly to a preparation method of a complex metal oxide catalyst that shows high activity for conversion of propylene or isobutylene, maintains good selectivity for such unsaturated aldehyde as acrolein or methacrolein and improves production yield of such unsaturated carboxylic acid as acrylic acid or methacrylic acid through stable process by using a drying control chemical additive.
1. A catalyst for partial oxidation having a surface area of 15-18 m 2 /g, which is represented by the following Chemical Formula 1:
[Chemical Formula 1]
Mo a Bi b Fe c X d Y e O f (1)
wherein
X is at least one element selected from the group consisting of Co and Ni;
Y is at least one element selected from the group consisting of K, Cs and Rb;
each of a, b, c, d, e and f represents the atomic mole ratio of each metal, and when a is 12, b is 0.5˜2, c is 0.5˜2, d is 3˜8, and e is 0.005˜0.2, and f is determined according to oxidation state of each metal.
2. A method of preparing a catalyst for partial oxidation represented by the following Chemical Formula 1, which comprises the steps of:
(a) dissolving an aqueous solution of at least one metal salt, the metal being selected from the group consisting of molybdenum, bismuth, iron, cobalt, nickel, potassium, cesium and rubidium in an organic acid and adding a drying control chemical additive to prepare a catalyst suspension;
(b) drying the catalyst suspension in vacuum and crushing it to obtain a catalyst powder; and
(c) calcining the catalyst powder in air
[Chemical Formula 1]
Mo a Bi b Fe c X d Y e O f (1)
wherein
X is at least one element selected from the group consisting of Co and Ni;
Y is at least one element selected from the group consisting of K, Cs and Rb;
each of a, b, c, d, e and f represents the atomic mole ratio of each metal, and when a is 12, b is 0.5˜2, c is 0.5˜2, d is 3˜8, and e is 0.005˜0.2, and f is determined according to oxidation state of each metal.
3. The method of claim 2 , wherein the drying control chemical additive is a material having a surface tension smaller than that of water and a boiling point higher than that of water.
4. The method of claim 2 , wherein the drying control chemical additive is at least one selected from the group consisting of glycerol, propionic acid, formamide, nitromethane, propyl alcohol, butyl alcohol, ethanediol, nitroethane, amyl acetate, ethyl propionate, ethyl malonate, furfurol, (α,β,γ)-picoline, piperidine, phenylhydrazine, 1-pentanol, 3-methylbutanol and isovaleric acid.
5. The method of claim 2 , wherein the drying control chemical additive is added in 10-60 wt % per 100 wt % of the organic acid.
6. The method of claim 2 , wherein the organic acid is at least one organic acid having 1 to 10 carbon atoms, which selected is selected from the group consisting of nitric acid, citric acid, maleic acid and oxalic acid.
7. A method of preparing an unsaturated carboxylic acid comprising the step of partially oxidizing an alkane, an alkene or a mixture thereof in the presence of a catalyst represented by the following Chemical Formula 1, which has been prepared by the method of claim 2 :
[Chemical Formula 1]
Mo a Bi b Fe c X d Y e O f (1)
wherein
X is at least one element selected from the group consisting of Co and Ni;
Y is at least one element selected from the group consisting of K, Cs and Rb;
each of a, b, c, d, e and f represents the atomic mole ratio of each metal, and when a is 12, b is 0.5˜2, c is 0.5˜2, d is 3˜8, and e is 0.005˜0.2, and f is determined according to oxidation state of each metal.
8. The method of claim 7 , wherein the unsaturated carboxylic acid is acrylic acid or methacrylic acid.
9. A method of preparing an unsaturated nitrile comprising the step of partially oxidizing an alkane, an alkene or a mixture thereof and ammonia in the presence of a catalyst represented by the following Chemical Formula 1, which has been prepared by the method of claim 2 :
[Chemical Formula 1]
Mo a Bi b Fe c X d Y e O f (1)
wherein
X is at least one element selected from the group consisting of Co and Ni;
Y is at least one element selected from the group consisting of K, Cs and Rb;
each of a, b, c, d, e and f represents the atomic mole ratio of each metal, and when a is 12, b is 0.5˜2, c is 0.5˜2, d is 3˜8, and e is 0.005˜0.2, and f is determined according to oxidation state of each metal.