Large scale synthesis of oxidative dehydrogenation catalyst
Catalysts and methods for large-scale production of the catalysts are described. An exemplary catalyst composition includes molybdenum, vanadium, tellurium, niobium, oxygen. In the catalyst composition, the molar ratio of molybdenum to vanadium is from 1:0.05 to 1:0.60, the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30, and the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.40. Oxygen is present at least in an amount to satisfy the valency of any present metal oxides, and the composition includes less than 1.0 wt. % of sulfur.
1 . A catalyst composition comprising molybdenum, vanadium, tellurium, niobium, oxygen, wherein:
the molar ratio of molybdenum to vanadium is from 1:0.05 to 1:0.60;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.40; and
wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides, and wherein the composition comprises from 0.001 wt. % to 0.90 wt. % sulfur.
2 . The catalyst composition of claim 1 , wherein the composition comprises less than 0.50 wt. % sulfur.
3 . The composition of claim 1 , wherein the composition comprises from 0.5 wt. % to 3.0 wt. % nitrogen.
4 . The composition of claim 1 , wherein the composition comprises 0.8 wt. % to 2.0 wt. % nitrogen.
5 . The composition of claim 1 , wherein the composition comprises 0.8 wt. % to 1.2 wt. % nitrogen.
6 . The composition of claim 1 , wherein the composition comprises less than 5.0 wt. % water.
7 . The composition of claim 1 , wherein the composition comprises from 0.01 wt. % to 2 wt. % water.
8 . The composition of claim 1 , wherein:
the molar ratio of molybdenum to vanadium is from 1:0.12 to 1:0.49;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.30.
9 . The composition of claim 1 , wherein the composition is prepared by a method comprising:
hydrothermally reacting an aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium to provide a prewashed composition comprising more than 0.5 wt. % sulfur; and
washing the prewashed composition with a solution comprising a polar solvent to provide the composition comprising less than 0.25 wt. % sulfur.
10 . The composition of claim 9 , wherein the polar solvent is water.
11 . A precalcined catalyst composition comprising molybdenum, vanadium, tellurium, niobium, oxygen, and sulfur, wherein:
the molar ratio of molybdenum to vanadium is from 1:0.05 to 1:0.60;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.05 to 1:0.40; and
wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides and sulfur comprises 0.001 wt. % to 0.25 wt. % of the composition; and
wherein the composition is prepared by a method comprising:
hydrothermally reacting an aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium to provide a prewashed ODH catalyst precursor comprising more than 0.5 wt. % sulfur; and
washing the prewashed ODH catalyst precursor with a solution comprising a water to provide the ODH catalyst precursor comprising less than 1.0 wt. % sulfur.
12 . A method of preparing a catalyst composition comprising molybdenum, vanadium, tellurium, niobium, oxygen, and, optionally, sulfur wherein:
the molar ratio of molybdenum to vanadium is from 1:0.05 to 1:0.60;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.05 to 1:0.40; and
wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides and sulfur, when present, comprises less than 0.25 wt. % of the composition; and
wherein the method comprises:
hydrothermally reacting an aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium to provide a prewashed catalyst composition comprising more than 0.5 wt. % sulfur; and
washing the prewashed catalyst composition with a solution comprising a polar solvent to provide the catalyst composition comprising less than 0.25 wt. % sulfur.
13 . The method of claim 12 , wherein the polar solvent comprises water.
14 . The method of claim 12 , wherein the composition comprises from 0.01 wt. % to 0.1 wt. % sulfur.
15 . The method of any one of claims 12 to 14 , wherein the composition comprises 0.8 wt. % to 2.0 wt. % nitrogen.
16 . The method of claim 12 , wherein the composition comprises 0.8 wt. % to 1.2 wt. % nitrogen.
17 . The method of claim 12 , wherein the method further comprises providing the aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium.
18 . The method of claim 17 , wherein providing the aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium comprises:
providing an aqueous mixture comprising molybdenum;
providing an aqueous mixture comprising tellurium;
providing an aqueous mixture comprising vanadium;
providing an aqueous mixture comprising niobium; and
combining the aqueous mixture comprising molybdenum, the aqueous mixture comprising tellurium, the aqueous mixture comprising vanadium, and the aqueous mixture comprising niobium, to provide the aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium.
19 . The method of claim 18 , wherein providing the aqueous mixture comprising niobium comprises preparing the aqueous mixture from at least a niobium pentoxide hydrate, oxalic acid, and a water.
20 . The method of claim 18 , wherein providing the aqueous mixture comprising tellurium comprises preparing the aqueous mixture from at least telluric acid (Te(OH) 6 ) and a water.
21 . The method of claim 18 , wherein providing the mixture comprising molybdenum comprises preparing the aqueous mixture from at least an ammonium molybdate tetrahydrate and a water.
22 . The method of claim 18 , wherein the method comprises:
combining the aqueous mixture comprising molybdenum with the aqueous mixture comprising tellurium to provide an aqueous mixture comprising molybdenum and tellurium;
combining the aqueous mixture comprising molybdenum and tellurium with the aqueous mixture comprising vanadium to provide an aqueous mixture comprising molybdenum, tellurium, and vanadium; and
combining the aqueous mixture comprising molybdenum, tellurium, and vanadium with the aqueous mixture comprising niobium to provide the aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium.
23 . The method of claim 22 , wherein the method further comprises increasing the pH of the aqueous mixture comprising molybdenum and tellurium to a pH from about 7.25 to about 7.75.
24 . The method of claim 22 , wherein the method further comprises decreasing the pH to a pH of about 4.75 to about 5.25.
25 . The method of claim 22 , wherein the method further comprises:
heating the aqueous mixture comprising molybdenum and tellurium to a temperature of about 70° C. to about 90° C.;
increasing the pH of the aqueous mixture comprising molybdenum and tellurium to a pH of about 7.25 to about 7.75;
agitating the aqueous mixture comprising molybdenum and tellurium for about 0.5 hours to about 24 hours; and
decreasing the pH of the aqueous mixture comprising molybdenum and tellurium to a pH of about 4.75 to about 5.25 prior to adding the aqueous mixture comprising vanadium to the aqueous mixture comprising molybdenum and tellurium to provide an aqueous mixture comprising molybdenum, tellurium, and vanadium.
26 . The method of claim 25 , wherein a washed catalyst composition is dried at a temperature of about 250° C.
27 . The method of claim 18 , wherein the average particle size of a comminuted catalyst composition is from about 125 μm to about 500 μm.
28 . The method of claim 17 , wherein providing the aqueous mixture comprising vanadium comprises preparing the aqueous mixture from a vanadium compound and a water.
29 . The method of claim 28 , wherein the vanadium compound comprises a vanadium compound selected from a vanadium acetylacetonate, a vanadyl acetylacetonate, a vanadyl stearate, a vanadium naphthenate, a vanadium benzoyl acetonate, a vanadyl sulfate, or a combination thereof.
30 . A catalyst material comprising molybdenum, vanadium, tellurium, niobium, and oxygen, wherein:
the molar ratio of molybdenum to vanadium is from 1:0.12 to 1:0.49;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.30; and
wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides, and wherein the catalyst material comprises from 0.001 wt. % to 0.01 wt. % sulfur.
31 . The catalyst material of claim 30 , wherein:
the molar ratio of molybdenum to vanadium is from 1:0.30 to 1:0.35;
the molar ratio of molybdenum to tellurium is from 1:0.13 to 1:0.17; and
the molar ratio of molybdenum to tellurium is from 1:0.12 to 1:0.14.
32 . The catalyst material of claim 30 , wherein the catalyst material comprises from 0.001 wt. % to 0.003 wt. % sulfur.
33 . The catalyst material of claim 30 , wherein the catalyst material further comprises from 0.5 wt. % to 0.3 wt. % nitrogen.
34 . The catalyst material of claim 30 , wherein the catalyst material comprises 27 wt. % to 33 wt. % oxygen.
35 . The catalyst material of claim 30 , wherein the catalyst material comprises a mixed metal oxide having the empirical formula Mo 1.0 V 0.30-0.35 Te 0.13-0.17 Nb 0.12-0.14 O d , wherein d is a number to satisfy the valence of the oxide.
36 . A method of preparing a catalyst material comprising molybdenum, vanadium, tellurium, niobium, oxygen, and, optionally, sulfur, the method comprising, the method comprising:
hydrothermally reacting an aqueous mixture comprising molybdenum, vanadium, tellurium, and niobium to provide a prewashed composition comprising more than 0.5 wt. % sulfur;
washing the prewashed composition with a solution comprising a polar solvent to provide a catalyst composition comprising molybdenum, vanadium, tellurium, niobium, oxygen, and, optionally, sulfur wherein:
the molar ratio of molybdenum to vanadium is from 1:0.05 to 1:0.60;
the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30; and
the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.40;
wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides and sulfur, when present, comprises less than 0.25 wt. % of the composition; and
calcining the catalyst composition to provide the catalyst material, and wherein the molar ratio of molybdenum to vanadium is from 1:0.12 to 1:0.49, the molar ratio of molybdenum to tellurium is from 1:0.01 to 1:0.30, and the molar ratio of molybdenum to niobium is from 1:0.01 to 1:0.30; and wherein oxygen is present at least in an amount to satisfy the valency of any present metal oxides and sulfur, when present, comprises less than 0.01 wt. % of the catalyst material.