Alkali metal and/or alkaline earth metal-doped transition metal-hydrogen active metal composite oxide catalyst and process for preparing butadiene using the same
In the present disclosure, a composite oxide catalyst capable of effectively suppressing side reactions at the time of dehydrogenation of C4 hydrocarbons having single bonds or one double bond and a process for preparing butadiene, in particular 1,3-butadiene, with a high selectivity and a high yield using the same are described.
1. A composite oxide catalyst for preparing 1,3-butadiene from C4 hydrocarbons via dehydrogenation, which comprises:
at least one first transition metal selected from the group consisting of gallium, vanadium, chromium, manganese, molybdenum, and zinc;
at least one hydrogen active metal selected from the group consisting of elements belonging to groups 8, 9, 10, and 11 of the periodic table;
at least one doping metal selected from the group consisting of elements belonging to groups 1 and 2 of the periodic table; and
alumina, wherein
a content of the first transition metal is determined in a range of 0.1% to 20% by weight based on a weight of alumina,
a content of the hydrogen active metal is determined at 0.09% by weight or less based on a weight of alumina,
a content of the doping metal is determined in a range of 0.01% to 5% by weight based on a weight of alumina,
the first transition metal and the doping metal are each contained in alumina in a solid solution form and the hydrogen active metal is surrounded by alumina containing the first transition metal and doping metal, whereby the doping metal is distributed in the acid sites of alumina to result in a controlled amount of acid sites,
a molar ratio of the first transition metal/hydrogen active metal is controlled in a range of 35 to 3000, and
a molar ratio of the first transition metal/doping metal is controlled in a range of 0.5 to 10.
2. The composite oxide catalyst according to claim 1 , wherein
the dehydrogenation catalyst further comprises at least one second transition metal selected from the group consisting of cerium and zirconium, and wherein
a content of the second transition metal is determined in a range of 0.1% to 20% by weight based on a weight of alumina and the second transition metal is in a form of being loaded on alumina, and
a molar ratio of the first transition metal/the second transition metal is in a range of 0.01 to 400.
3. The composite oxide catalyst according to claim 2 , wherein the second transition metal is cerium (Ce) and/or zirconium (Zr).
4. The composite oxide catalyst according to claim 2 , wherein the first transition metal, the second transition metal, the hydrogen active metal, and the doping metal are gallium, cerium, platinum, and potassium, respectively.
5. The composite oxide catalyst according to claim 1 , wherein the hydrogen active metal is at least one selected from the group consisting of Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au.
6. The composite oxide catalyst according to claim 1 , wherein a content of the hydrogen active metal is determined in a range of 0.03% to 0.09% by weight based on a weight of alumina.
7. The composite oxide catalyst according to claim 1 , wherein the doping metal is at least one selected from the group consisting of K, Cs, Mg, and Ca.
8. The composite oxide catalyst according to claim 1 , wherein the amount of acid sites of the dehydrogenation catalyst is in a range of 50 to 700 μmol/g as measured by NH 3 temperature programmed desorption.
9. A process for preparing 1,3-butadiene, from C4 hydrocarbons, which comprises:
providing a feedstock containing C4 hydrocarbons having a single bond or one double bond;
subjecting the C4 hydrocarbons in the feedstock to dehydrogenation in presence of the composite oxide catalyst according to claim 1 to form a product containing 1,3-butadiene in an increased content; and
recovering 1,3-butadiene from the product.
10. The process for preparing 1,3-butadiene according to claim 9 , wherein the dehydrogenation is conducted at a temperature of 300° C. to 800° C.
11. The process for preparing 1,3-butadiene according to claim 9 , wherein a content of C4 hydrocarbons in the feedstock is at least 10 mol %, a content of hydrocarbons having less than 4 carbon atoms in the feedstock is less than 90 mol %, and a content of hydrocarbons having more than 4 carbon atoms in the feedstock is less than 90 mol %.
12. The process for preparing 1,3-butadiene according to claim 11 , wherein a content of C4 paraffins among the C4 hydrocarbons is at least 10 mol %.
13. A process for preparing a composite oxide catalyst for preparing 1,3-butadiene from C4 hydrocarbons via dehydrogenation, which comprises:
a) providing a precursor of at least one first transition metal selected from the group consisting of gallium, vanadium, chromium, manganese, molybdenum, and zinc;
b) providing a precursor of at least one hydrogen active metal selected from the group consisting of elements belonging to groups 8, 9, 10, and 11 of the periodic table;
c) providing a precursor of at least one doping metal selected from the group consisting of elements belonging to groups 1 and 2 of the periodic table;
d) providing a precursor of alumina;
e) mixing the precursor of first transition metal, the precursor of hydrogen active metal, the precursor of doping metal, and the precursor of alumina in one pot to form a one-pot precursor mixture; and
f) reacting the one-pot precursor mixture by a sol-gel method to synthesize a catalyst, and
g) drying the synthesized catalyst, followed by subjecting to calcination to prepare a catalyst in a composite oxide form;
wherein a content of the first transition metal is determined in a range of 0.1% to 20% by weight based on a weight of alumina,
a content of the hydrogen active metal is determined at 0.09% by weight or less based on a weight of alumina,
a content of the doping metal is determined in a range of 0.01% to 5% by weight based on a weight of alumina,
the first transition metal and the doping metal are each contained in alumina in a solid solution form and the hydrogen active metal is surrounded by alumina containing the first transition metal and doping metal, whereby the doping metal is distributed in the acid sites of alumina to result in a controlled amount of acid sites,
a molar ratio of the first transition metal/hydrogen active metal is controlled in a range of 35 to 3000, and
a molar ratio of the first transition metal/doping metal is controlled in a range of 0.5 to 10.
14. The process for preparing a composite oxide catalyst according to claim 13 , wherein the process further comprises mixing a precursor of at least one second transition metal selected from the group consisting of cerium and zirconium in the one pot, and wherein
a content of the second transition metal is determined in a range of 0.1% to 20% by weight based on a weight of alumina in the dehydrogenation catalyst.
15. The process for preparing a composite oxide catalyst according to claim 14 , wherein the first transition metal precursor and the second transition metal precursor are each at least one selected from the group consisting of a nitrate, a sulfate, an acetate, a formate, and a halide.
16. The process for preparing a composite oxide catalyst according to claim 13 , wherein the drying is performed at 50° C. to 200° C. and the calcination is performed in an oxygen-containing atmosphere at a temperature of 350° C. to 1000° C.
17. The process for preparing a composite oxide catalyst according to claim 13 , wherein the one-pot precursor mixture is in a form of a precursor solution dissolved in a solvent, and wherein the solvent is an aqueous medium.
18. The process for preparing a composite oxide catalyst according to claim 13 , wherein the precursor of alumina is at least one selected from the group consisting of aluminum acetate, aluminum acetylacetonate, aluminum t-butoxide, aluminum sec-butoxide, aluminum pentoxide, aluminum ethoxide, aluminum isopropoxide, aluminum tributoxide, aluminum fluoride, aluminum chloride, aluminum bromide, aluminum iodide, aluminum sulfate, aluminum nitrate, and any hydrate thereof.
19. The process for preparing a composite oxide catalyst according to claim 13 , wherein the precursor of hydrogen active metal is a platinum precursor and is at least one selected from the group consisting of a hydride, a fluoride, a chloride, a bromide, an iodide, an oxide, a sulfide, a carbonyl, and a complex.