WO2006067129A2 - Titanium-zirconium mixed oxide powder - Google Patents
Titanium-zirconium mixed oxide powder Download PDFInfo
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- WO2006067129A2 WO2006067129A2 PCT/EP2005/056938 EP2005056938W WO2006067129A2 WO 2006067129 A2 WO2006067129 A2 WO 2006067129A2 EP 2005056938 W EP2005056938 W EP 2005056938W WO 2006067129 A2 WO2006067129 A2 WO 2006067129A2
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- WIPO (PCT)
- Prior art keywords
- titanium
- zirconium
- mixed oxide
- dioxide
- oxide powder
- Prior art date
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- 239000000843 powder Substances 0.000 title claims abstract description 44
- PMTRSEDNJGMXLN-UHFFFAOYSA-N titanium zirconium Chemical compound [Ti].[Zr] PMTRSEDNJGMXLN-UHFFFAOYSA-N 0.000 title claims abstract description 27
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 48
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 26
- 238000002156 mixing Methods 0.000 claims abstract description 19
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000004408 titanium dioxide Substances 0.000 claims abstract description 18
- 239000007858 starting material Substances 0.000 claims abstract description 14
- 238000006243 chemical reaction Methods 0.000 claims abstract description 12
- 239000001257 hydrogen Substances 0.000 claims abstract description 9
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 9
- 239000011164 primary particle Substances 0.000 claims abstract description 9
- 230000004048 modification Effects 0.000 claims abstract description 8
- 238000012986 modification Methods 0.000 claims abstract description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 238000002441 X-ray diffraction Methods 0.000 claims abstract description 7
- 239000003054 catalyst Substances 0.000 claims abstract description 5
- RKTYLMNFRDHKIL-UHFFFAOYSA-N copper;5,10,15,20-tetraphenylporphyrin-22,24-diide Chemical compound [Cu+2].C1=CC(C(=C2C=CC([N-]2)=C(C=2C=CC=CC=2)C=2C=CC(N=2)=C(C=2C=CC=CC=2)C2=CC=C3[N-]2)C=2C=CC=CC=2)=NC1=C3C1=CC=CC=C1 RKTYLMNFRDHKIL-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000000203 mixture Substances 0.000 claims abstract description 4
- 239000010987 cubic zirconia Substances 0.000 claims abstract description 3
- 150000003609 titanium compounds Chemical class 0.000 claims description 13
- 150000003755 zirconium compounds Chemical class 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 12
- 238000002360 preparation method Methods 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 6
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 claims description 5
- DUNKXUFBGCUVQW-UHFFFAOYSA-J zirconium tetrachloride Chemical compound Cl[Zr](Cl)(Cl)Cl DUNKXUFBGCUVQW-UHFFFAOYSA-J 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 239000012159 carrier gas Substances 0.000 claims description 2
- 150000002736 metal compounds Chemical class 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 abstract description 4
- 239000003570 air Substances 0.000 description 18
- 230000007062 hydrolysis Effects 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229910003074 TiCl4 Inorganic materials 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910007932 ZrCl4 Inorganic materials 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- -1 compounds titanium tetrachloride Chemical class 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G25/00—Compounds of zirconium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/063—Titanium; Oxides or hydroxides thereof
-
- B01J35/30—
-
- B01J35/613—
-
- B01J35/615—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
- B01J37/086—Decomposition of an organometallic compound, a metal complex or a metal salt of a carboxylic acid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/34—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation
- B01J37/349—Irradiation by, or application of, electric, magnetic or wave energy, e.g. ultrasonic waves ; Ionic sputtering; Flame or plasma spraying; Particle radiation making use of flames, plasmas or lasers
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/003—Titanates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Definitions
- the invention relates to a titanium-zirconium mixed oxide powder and its use, and to a process for the preparation of titanium-zirconium mixed oxide powders .
- DE-A-3611449 discloses a titanium-zirconium mixed oxide powder which comprises at least 5 wt . % of a mixed oxide component .
- the mixed oxide powder is obtained by a process of flame hydrolysis , in which anhydrous zirconium tetrachloride is transported by means of an inert gas into a mixing chamber and is there mixed with hydrogen, air and titanium tetrachloride, and the mixture is burnt in a reaction chamber .
- the mixed oxide powder so prepared exhibits reflections of zirconium dioxide, titanium dioxide and zirconium titanate phases in X-ray diffraction analysis .
- the mixed oxide powder can be used as a catalyst support .
- the obj ect of the invention is to provide a titanium- zirconium mixed oxide powder which, compared with the prior art, exhibits greater thermal stability than catalyst supports .
- a further obj ect of the invention is to provide a process for the preparation of titanium-zirconium mixed oxide powders .
- the invention provides a titanium-zirconium mixed oxide powder in the form of aggregated primary particles , which powder
- - has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt . %, wherein the sum of the contents of titanium dioxide and zirconium dioxide is at least 99.7 wt . % and wherein the contents are in each case based on the total amount of powder, - exhibits reflections of titanium dioxide modifications and does not exhibit reflections of monoclinic, tetragonal and cubic zirconium dioxide in X-ray diffraction analysis .
- the titanium-zirconium mixed oxide powder according to the invention is in the form of aggregates of primary particles .
- the primary particles are not porous .
- the surfaces of these primary particles have hydroxyl groups .
- Mixed oxide powder is to be understood as meaning a powder in which intimate mixing of titanium dioxide and zirconium dioxide at primary particle or aggregate level is to be understood.
- the primary particles exhibit Zr-O-Ti bonds .
- areas of zirconium dioxide can also be present in the primary particles in addition to titanium dioxide .
- the titanium-zirconium mixed oxide powder according to the invention exhibits rutile and anatase as titanium dioxide modification .
- the content of the titanium dioxide modification rutile in the titanium-zirconium mixed oxide powder according to the invention can preferably be at least 5 wt . %, particularly preferably at least 20 wt . %, based on the sum of rutile and anatase .
- the X-ray diffraction analysis can exhibit the reflections of titanium-zirconium mixed phases .
- the BET surface area determined in accordance with DIN 66131 , can preferably be from 10 to 200 m 2 /g and particularly preferably from 40 to 120 m 2 /g .
- the invention further provides a process for the preparation of titanium-zirconium mixed oxide powders , in which
- a titanium compound or zirconium compound in vapour form is transported by means of primary air into a mixing chamber, wherein the primary air, which can optionally be enriched with oxygen and/or preheated, is supplied in such an amount that at least 50 % of the starting compounds for the first and second mixed oxide components can be converted into the oxides thereby, corresponding to a lambda( pr ) value of at least 0.5, and as starting compound for the second mixed oxide component, a zirconium compound or titanium compound in vapour form is likewise transported into the mixing chamber, separately from the starting compound for the first mixed oxide component, by means of an inert carrier gas , wherein the amounts of the titanium compounds and zirconium compounds in vapour form that are used are so chosen that the mixed oxide powder has a content of titanium dioxide of from 40 to 97 wt .
- hydrogen is introduced into the mixing chamber separately from the titanium compounds and zirconium compounds in vapour form, and the mixture of titanium compounds and zirconium compounds in vapour form, hydrogen and primary air is ignited in a burner and the flame burns into a reaction chamber, - the solid is then separated from gaseous substances , and the solid is then treated with steam at temperatures of from 250 to 700°C, wherein, in the case where lambda( pr ) is less than 1.0 , an amount of secondary air is added to the reaction chamber to give a value of lambda( pr+ sec) of at least 1.0 , and wherein gamma is > 1.
- An important feature of the process according to the invention is that the starting compound for the first mixed oxide component and at least 50 % of the air that is necessary stoichiometrically in order to convert the starting compounds for the first and second mixed oxide components into the mixed oxide powder according to the invention are introduced into the mixing chamber together .
- a further important feature is that the starting compound for the second mixed oxide component is transported into the mixing chamber by means of an inert gas .
- both the titanium compound and the zirconium compound can be introduced into the burner with the primary air . It has proved advantageous for the metal compound that is greater in terms of amount to be introduced into the mixing chamber with the primary air .
- the gamma value is > 1 , preferably from 1 to 6.
- Figure 1 shows the process according to the invention in diagrammatic form.
- a titanium or zirconium compound in vapour form
- ai primary air
- b zirconium or titanium compound in vapour form
- bi inert gas
- c hydrogen
- d secondary air
- I mixing chamber
- II reaction chamber .
- the titanium compounds and zirconium compounds in vapour form are converted into the corresponding metal oxide either by hydrolysis or by oxidation .
- Suitable compounds may be halides , nitrates , alcoholates and/or carboxylates .
- Hydrolysis can be illustrated with reference to the compounds titanium tetrachloride and zirconium tetrachloride, which are preferably used, as follows , the water originating from the reaction of the (atmospheric) oxygen with hydrogen :
- the process according to the invention can preferably be carried out in such a manner that lambda( pr ) is from 0.7 to 2.
- secondary air can be introduced into the reaction chamber regardless of whether lambda( pr ) is less than 1.
- lambda ⁇ pr + seC ) is from > 1 to 7 , particularly preferably lambda( pr + seC ) is from 1.2 to 4.
- the invention relates also to the use of the titanium- zirconium mixed oxide powder as a catalyst support .
- Examples 2 to 5 are carried out analogously to Example 1.
- the amounts of the substances used and the physico-chemical values of the powders in each case are shown in Table 1.
- the powders of Examples 1 to 3 exhibit only the reflections of titanium dioxide modifications in the X-ray diffraction diagram, but not reflections of zirconium dioxide modifications .
- the powders of Examples 4 and 5 additionally exhibit reflections of titanium-zirconium mixed phases , namely Ti 2 ZrO 6 and ZrTiO 4 .
- Table 2 shows the behaviour of the BET surface area of the powders according to the invention of Examples 1 , 2 and 4 compared with Aeroxide® TiO 2 P 25, BET surface area 45 m 2 /g (Degussa) and a zirconium dioxide sample (VP ZrO 2 , BET surface area 52 m 2 /g) , on thermal loading .
Abstract
Titanium-zirconium mixed oxide powder in the form of aggregated primary particles, which powder has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt.%, wherein the sum of the contents of titanium dioxide and zirconium dioxide is at least 99.7 wt.% and wherein the contents are in each case based on the total amount of powder, and which exhibits reflections of titanium dioxide modifications and does not exhibit reflections of monoclinic, tetragonal and cubic zirconium dioxide in X-ray diffraction analysis. It is prepared by transporting into a mixing chamber a starting compound, in vapour form, for the first mixed oxide component by means of primary air and a starting compound, in vapour form, for the second mixed oxide component by means of an inert gas, mixing the mixture with hydrogen in a mixing chamber and burning it into a reaction chamber. It can be used as a catalyst support.
Description
Titanium-zirconium mixed oxide powder
The invention relates to a titanium-zirconium mixed oxide powder and its use, and to a process for the preparation of titanium-zirconium mixed oxide powders .
DE-A-3611449 discloses a titanium-zirconium mixed oxide powder which comprises at least 5 wt . % of a mixed oxide component . The mixed oxide powder is obtained by a process of flame hydrolysis , in which anhydrous zirconium tetrachloride is transported by means of an inert gas into a mixing chamber and is there mixed with hydrogen, air and titanium tetrachloride, and the mixture is burnt in a reaction chamber . The mixed oxide powder so prepared exhibits reflections of zirconium dioxide, titanium dioxide and zirconium titanate phases in X-ray diffraction analysis . The mixed oxide powder can be used as a catalyst support .
The obj ect of the invention is to provide a titanium- zirconium mixed oxide powder which, compared with the prior art, exhibits greater thermal stability than catalyst supports .
A further obj ect of the invention is to provide a process for the preparation of titanium-zirconium mixed oxide powders .
The invention provides a titanium-zirconium mixed oxide powder in the form of aggregated primary particles , which powder
- has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt . %, wherein the sum of the contents of titanium dioxide and zirconium dioxide is at least 99.7 wt . % and wherein the contents are in each case based on the total amount of powder,
- exhibits reflections of titanium dioxide modifications and does not exhibit reflections of monoclinic, tetragonal and cubic zirconium dioxide in X-ray diffraction analysis .
The titanium-zirconium mixed oxide powder according to the invention is in the form of aggregates of primary particles . The primary particles are not porous . The surfaces of these primary particles have hydroxyl groups .
Mixed oxide powder is to be understood as meaning a powder in which intimate mixing of titanium dioxide and zirconium dioxide at primary particle or aggregate level is to be understood. The primary particles exhibit Zr-O-Ti bonds . In addition, areas of zirconium dioxide can also be present in the primary particles in addition to titanium dioxide .
The titanium-zirconium mixed oxide powder according to the invention exhibits rutile and anatase as titanium dioxide modification . The reflections of monoclinic ZrC>2 at 2 theta = 28.2°, tetragonal ZrO2 at 2 theta = 30.1°, 49.7° and 59.7° and cubic ZrO2 at 2 theta = 30.5°, 50.6°, 35.1° and 60.4° are not detectable .
The content of the titanium dioxide modification rutile in the titanium-zirconium mixed oxide powder according to the invention can preferably be at least 5 wt . %, particularly preferably at least 20 wt . %, based on the sum of rutile and anatase .
In the case of a zirconium dioxide content of more than 40 wt . %, the X-ray diffraction analysis can exhibit the reflections of titanium-zirconium mixed phases .
The BET surface area, determined in accordance with DIN 66131 , can preferably be from 10 to 200 m2/g and particularly preferably from 40 to 120 m2/g .
The invention further provides a process for the preparation of titanium-zirconium mixed oxide powders , in which
as starting compound for the first mixed oxide component, a titanium compound or zirconium compound in vapour form is transported by means of primary air into a mixing chamber, wherein the primary air, which can optionally be enriched with oxygen and/or preheated, is supplied in such an amount that at least 50 % of the starting compounds for the first and second mixed oxide components can be converted into the oxides thereby, corresponding to a lambda(pr) value of at least 0.5, and as starting compound for the second mixed oxide component, a zirconium compound or titanium compound in vapour form is likewise transported into the mixing chamber, separately from the starting compound for the first mixed oxide component, by means of an inert carrier gas , wherein the amounts of the titanium compounds and zirconium compounds in vapour form that are used are so chosen that the mixed oxide powder has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt . %, hydrogen is introduced into the mixing chamber separately from the titanium compounds and zirconium compounds in vapour form, and the mixture of titanium compounds and zirconium compounds in vapour form, hydrogen and primary air is ignited in a burner and the flame burns into a reaction chamber, - the solid is then separated from gaseous substances , and the solid is then treated with steam at temperatures of from 250 to 700°C, wherein, in the case where lambda(pr) is less than 1.0 , an amount of secondary air is added to the reaction chamber to give a value of lambda(pr+sec) of at least 1.0 , and
wherein gamma is > 1.
An important feature of the process according to the invention is that the starting compound for the first mixed oxide component and at least 50 % of the air that is necessary stoichiometrically in order to convert the starting compounds for the first and second mixed oxide components into the mixed oxide powder according to the invention are introduced into the mixing chamber together .
A further important feature is that the starting compound for the second mixed oxide component is transported into the mixing chamber by means of an inert gas .
It is possible for both the titanium compound and the zirconium compound to be introduced into the burner with the primary air . It has proved advantageous for the metal compound that is greater in terms of amount to be introduced into the mixing chamber with the primary air .
It is also important that, if the air introduced into the mixing chamber is not sufficient to convert the starting compounds completely into the mixed oxide powder according to the invention, secondary air is introduced into the reaction chamber .
It is also important that the gamma value is > 1 , preferably from 1 to 6.
Figure 1 shows the process according to the invention in diagrammatic form. In the figure : a = titanium or zirconium compound in vapour form; ai = primary air; b = zirconium or titanium compound in vapour form; bi = inert gas ; c = hydrogen; d = secondary air; I = mixing chamber; II = reaction chamber .
The titanium compounds and zirconium compounds in vapour form are converted into the corresponding metal oxide either by hydrolysis or by oxidation . Suitable compounds may be halides , nitrates , alcoholates and/or carboxylates .
Hydrolysis can be illustrated with reference to the compounds titanium tetrachloride and zirconium tetrachloride, which are preferably used, as follows , the water originating from the reaction of the (atmospheric) oxygen with hydrogen :
TiCl4 + 2H2O -> TiO2 + 4HCl; 2ZrCl4 + 2H2O -> ZrO2 + 4HCl
Gamma and lambda are defined as follows : gamma = H2 supplied / H2 required stoichiometrically, lambda = O2 supplied / O2 required stoichiometrically . Lambda includes the total amount of oxygen introduced from the primary air and the secondary- air .
The process according to the invention can preferably be carried out in such a manner that lambda(pr) is from 0.7 to 2.
In the process according to the invention, secondary air can be introduced into the reaction chamber regardless of whether lambda(pr) is less than 1. Preferably, lambda<pr + seC) is from > 1 to 7 , particularly preferably lambda(pr + seC) is from 1.2 to 4.
The invention relates also to the use of the titanium- zirconium mixed oxide powder as a catalyst support .
Examples :
Example 1 :
1.63 kg/h of TiCl4 are vaporised. The vapours are transported into a mixing chamber by means of primary air (3.08 NmVh) . Separately therefrom, 0.11 kg/h of ZrCl4 are vaporised and are likewise transported into the mixing chamber, by means of nitrogen . Separately from the titanium tetrachloride and the zirconium tetrachloride, 0.30 Nm3/h of hydrogen are introduced into the mixing chamber . In a central pipe, the reaction mixture is fed to a burner and ignited. The flame thereby burns into a water-cooled reaction chamber . 0.30 Nm3/h of secondary air are additionally introduced into the reaction chamber . The powder that forms is separated off in a downstream filter and then treated countercurrently with air and steam at about 700°C .
Examples 2 to 5 are carried out analogously to Example 1. The amounts of the substances used and the physico-chemical values of the powders in each case are shown in Table 1.
The powders of Examples 1 to 3 exhibit only the reflections of titanium dioxide modifications in the X-ray diffraction diagram, but not reflections of zirconium dioxide modifications . The powders of Examples 4 and 5 additionally exhibit reflections of titanium-zirconium mixed phases , namely Ti2ZrO6 and ZrTiO4.
Table 2 shows the behaviour of the BET surface area of the powders according to the invention of Examples 1 , 2 and 4 compared with Aeroxide® TiO2 P 25, BET surface area 45 m2/g (Degussa) and a zirconium dioxide sample (VP ZrO2, BET surface area 52 m2/g) , on thermal loading .
The Examples show that the powders according to the invention exhibit a high stability of the BET surface area on thermal loading .
Table 1 : Substances and amounts used; physico-chemical values of the titanium-zirconium mixed oxide powders
Table 2 : Stability of the BET surface area on thermal treatment
Claims
1. Titanium-zirconium mixed oxide powder in the form of aggregated primary particles , characterised in that it has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt . %, wherein the sum of the contents of titanium dioxide and zirconium dioxide is at least 99.7 wt . % and wherein the contents are in each case based on the total amount of powder, - it exhibits reflections of titanium dioxide modifications and no reflections of monoclinic, tetragonal and cubic zirconium dioxide in X-ray diffraction analysis .
2. Titanium-zirconium mixed oxide powder according to claim 1 , characterised in that the content of the titanium dioxide modification rutile is at least 5 wt . %, based on the sum of rutile and anatase .
3. Titanium-zirconium mixed oxide powder according to claim 1 , characterised in that, in the case of a zirconium dioxide content of more than 40 wt . %, it exhibits the reflections of titanium-zirconium mixed phases in X-ray diffraction analysis .
4. Titanium-zirconium mixed oxide powder according to claim 1 or 2 , characterised in that the BET surface area is from 10 to 200 m2/g .
5. Process for the preparation of titanium-zirconium mixed oxide powders , characterised in that as starting compound for the first mixed oxide component, a titanium compound or zirconium compound in vapour form is transported by means of primary air into a mixing chamber, wherein the primary air, which can optionally be enriched with oxygen and/or preheated, is supplied in such an amount that at least 50 % of the starting compounds for the first and second mixed oxide components can be converted into the oxides thereby, corresponding to a lambda(pr> value of at least 0.5, and as starting compound for the second mixed oxide component, a zirconium compound or titanium compound in vapour form is likewise transported into the mixing chamber, separately from the starting compound for the first mixed oxide component, by means of an inert carrier gas ,
- wherein the amounts of the titanium compounds and zirconium compounds in vapour form that are used are so chosen that the mixed oxide powder has a content of titanium dioxide of from 40 to 97 wt . % and a content of zirconium dioxide of from 3 to 60 wt . %,
- hydrogen is introduced into the mixing chamber separately from the titanium compounds and zirconium compounds in vapour form, and the mixture of titanium compounds and zirconium compounds in vapour form, hydrogen and primary air is ignited in a burner and the flame burns into a reaction chamber, the solid is then separated from gaseous substances , and - the solid is then treated with steam at temperatures of from 250 to 700°C,
- wherein, in the case where lambda(pr) is less than 1.0 , an amount of secondary air is added to the reaction chamber to give a value of lambda(pr+sec) of at least 1.0 , and
- wherein gamma is > 1.
6. Process for the preparation of the titanium-zirconium mixed oxide powder according to claim 5, characterised in that the metal compounds in vapour form are titanium tetrachloride and zirconium tetrachloride .
7. Process for the preparation of the titanium-zirconium mixed oxide powder according to claim 5 or 6, characterised in that lambda(pr) is from 0.7 to 4.
8. Process for the preparation of the titanium-zirconium mixed oxide powder according to claims 5 to 1 , characterised in that lambda(pr + seC) is from > 1 to 7.
9. Use of the titanium-zirconium mixed oxide powder according to claims 1 to 4 as a catalyst support .
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102004061702A DE102004061702A1 (en) | 2004-12-22 | 2004-12-22 | Titanium-aluminum mixed oxide powder |
| DE102004061702.3 | 2004-12-22 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2006067129A2 true WO2006067129A2 (en) | 2006-06-29 |
| WO2006067129A3 WO2006067129A3 (en) | 2007-10-25 |
Family
ID=36590425
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2005/056938 WO2006067129A2 (en) | 2004-12-22 | 2005-12-20 | Titanium-zirconium mixed oxide powder |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE102004061702A1 (en) |
| WO (1) | WO2006067129A2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102007031635A1 (en) | 2007-07-06 | 2009-01-15 | Evonik Degussa Gmbh | Process for the preparation of metal oxide granules |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0241647A2 (en) * | 1986-04-05 | 1987-10-21 | Degussa Aktiengesellschaft | Basic products for the manufacture of ceramic materials |
| US5684116A (en) * | 1994-01-07 | 1997-11-04 | Akzo Nobel, N.V. | Titanium dioxide/silicon dioxide coprecipitates and titanium dioxide/zirconium dioxide coprecipitates as polycondensation catalysts for polyesters and copolyesters |
| EP1138632A1 (en) * | 2000-03-29 | 2001-10-04 | Degussa AG | Doped titanium dioxide |
-
2004
- 2004-12-22 DE DE102004061702A patent/DE102004061702A1/en not_active Withdrawn
-
2005
- 2005-12-20 WO PCT/EP2005/056938 patent/WO2006067129A2/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0241647A2 (en) * | 1986-04-05 | 1987-10-21 | Degussa Aktiengesellschaft | Basic products for the manufacture of ceramic materials |
| US5684116A (en) * | 1994-01-07 | 1997-11-04 | Akzo Nobel, N.V. | Titanium dioxide/silicon dioxide coprecipitates and titanium dioxide/zirconium dioxide coprecipitates as polycondensation catalysts for polyesters and copolyesters |
| EP1138632A1 (en) * | 2000-03-29 | 2001-10-04 | Degussa AG | Doped titanium dioxide |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2006067129A3 (en) | 2007-10-25 |
| DE102004061702A1 (en) | 2006-07-06 |
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