TiO2 based catalyst precursor material, production thereof and use thereof

Abstract

A TiO.sub.2-based catalyst precursor material in powder form includes TiO.sub.2 particles with the formula TiO.sub.(2-x)(OH).sub.2x (x=0-1). The particles are coated with one or more auxiliary shaping agents and after coating and drying have a specific surface area of at least 150 m.sup.2/g. The material has a content of 1) 50-99.5% by weight of the titanium-oxygen compound with the general formula TiO.sub.(2-x)(OH).sub.2x, wherein x=0 to 1, or mixtures thereof, wherein the crystalline phases of the titanium-oxygen compound are in the anatase form, and 2) 0.5-50% by weight of an auxiliary shaping agent or mixtures thereof, which evaporates, sublimates and/or decomposes upon heating to temperatures below the transformation temperature from anatase to rutile, wherein the % by weight are relative to the total weight of the dried catalyst precursor material.

Claims

1. TiO.sub.2-based catalyst precursor material in powder form containing TiO.sub.2 particles with the formula TiO.sub.(2-x)(OH).sub.2x (x=0-1), wherein the particles are coated with one or more auxiliary shaping agents, and after coating and drying have a specific surface area of at least 150 m.sup.2/g and comprise: 50-99.5% by weight of the titanium-oxygen compound with the general formula TiO.sub.(2-x)(OH).sub.2x, wherein x=0 to 1, or mixtures thereof, wherein the crystalline phases of the titanium-oxygen compound are in the anatase form, 0.5-50% by weight of an auxiliary shaping agent or mixtures thereof, which evaporates, sublimates and/or decomposes upon heating to temperatures from below the transformation temperature from anatase to rutile, 915 C., wherein the % by weight are relative to the total weight of the dried catalyst precursor material.

2. TiO.sub.2-based catalyst precursor material in powder form according to claim 1, comprising: 70-99.5% by weight of the titanium-oxygen compound with general formula TiO.sub.(2-x)(OH).sub.2x wherein x=0, or mixtures thereof, and 0.5-30% by weight of the auxiliary shaping agent, wherein the % by weight are relative to the total weight of the dried catalyst precursor material.

3. TiO.sub.2-based catalyst precursor material in powder form according to claim 1 further comprising 0.1-20% by weight SiO.sub.2, and/or Al.sub.2O.sub.3, wherein the % by weight are relative to the total weight of the dried catalyst precursor material.

4. TiO.sub.2-based catalyst precursor material in powder form according to claim 1 further comprising 0.1-30% by weight CaSO.sub.4, BaSO.sub.4 or mixtures thereof, wherein the % by weight are relative to the total weight of the dried catalyst precursor material.

5. TiO.sub.2-based catalyst precursor material in powder form according to claim 1, wherein the auxiliary shaping agent is selected from the group consisting of: an organic hydrocarbon containing at least one functional group selected from the group consisting of hydroxy, carboxy, amino, imino, amido, ester, sulfonyl, keto, and thio analogues thereof, or mixtures thereof, carbohydrates selected from the group consisting of cellulose, cellulose ether, methyl cellulose, glucose, polyacryl amines, polyvinyl alcohol, stearic acid, polyethylene glycol and mixtures thereof, ammonia, alkanol amine or an ammonia-releasing compound or mixtures thereof, and nitric acid.

6. TiO.sub.2-based catalyst precursor material in powder form according to claim 1 having a pore volume of at least 0.25 cm.sup.3/g.

7. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 1, comprising: an aqueous suspension of titanium oxide hydrate particles and/or hydrated titanium dioxide particles having general formula TiO.sub.(2-x)(OH).sub.2x (0<x1) is mixed with the auxiliary shaping agent or a suspension or solution of the des shaping agent, and the suspension obtained is dried at a temperature below 150 C. and, optionally undergoes a grinding step.

8. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 7, wherein: the aqueous suspension of titanium oxide hydrate particles and/or hydrated titanium dioxide particles having general formula TiO.sub.(2-x)(OH).sub.2x (0<x1) is obtained in that a suspension of metatitanic acid is neutralised with an alkali, optionally, the neutralised metatitanic acid is washed with water, optionally, the washed metatitanic acid is readsorbed.

9. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 8, wherein: the suspension of metatitanic acid is neutralised with an alkali selected from the group consisting of NaOH, ammonia, calcium carbonate, calcium hydroxide, and Ba(OH).sub.2.

10. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 8, wherein: the neutralised metatitanic acid is washed with water until it has a conductivity not greater than 500 S/cm.

11. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 7, wherein: the titanium oxide hydrate particles and/or hydrated titanium dioxide particles having general formula TiO.sub.(2-x)(OH).sub.2x (0<x1) in the aqueous suspension have an average particle size of 5 nm-5 m.

12. Method for producing the TiO.sub.2-based catalyst precursor material in powder form according to claim 7, wherein the suspension obtained after the addition of the auxiliary shaping agent solution undergoes a maturation step for 10 min up to 24 h at temperatures from 20-80 C.

13. Method for producing the TiO.sub.2-containing shaped parts comprising: catalyst precursor material in powder form according to claim 1 is mixed with a peptising agent and water, and optionally a further additive selected from the group consisting of plasticisers, binders, bases, lubricants and pore forming agents, or mixtures thereof, to form a mixture, the mixture obtained thereby undergoes a further mixing process, the mixture obtained thereby is moulded in a moulding device to create a shaped part, the shaped part is dried at a temperature below 150 C. and then calcined at a temperature below the transformation temperature of anatase into rutile 915 C.

14. Method for producing the TiO.sub.2-containing shaped parts according to claim 11, wherein the mixture obtained is extruded with an extruder as the moulding device to form a string-like extrudate.

15. Method for producing the TiO.sub.2-containing shaped parts according to claim 13 or 14, in which the quantity of water is selected such that the mixture obtained can be extruded as a kneaded paste by the extruder at a pressure of 1 to 200 bar to form an extrudate.

16. Method for producing the TiO.sub.2-containing shaped parts according to claim 14, in which the extrudate is dried in a temperature range from 80- 120 C., for 60 to 120 min, and then annealed for 1-4 hours at 300 to 600.

17. TiO.sub.2-containing shaped part producible according to the method according to claim 13.

18. A catalyst or carrier for catalytically active metal comprising a TiO.sub.2-based catalyst precursor material according to claim 1 in a process selected from the group consisting of photocatalysis, Claus catalysis, Claus tail gas treatment, SCR, hydrotreating, gas-to-liquid processes, and Fischer-Tropsch processes.

19. A catalyst or carrier for a catalytically active metal comprising a TiO.sub.2-containing shaped part according to claim 17 in a process selected from the group consisting of photocatalysis, Claus catalysis, Claus tail gas treatment, SCR, hydrotreating, gas-to-liquid processes, and Fischer-Tropsch processes.

Description

EXAMPLES

Example 1

[0131] Hombikat MTSA (metatitanic acid, a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water until the conductivity in the filtrate is below 200 S/cm. The filter cake is redispersed and reacted with an aqueous solution of oxalic acid (corresponding to 6 g oxalic acid dihydrate to 94 g TiO.sub.2). This suspension is allowed to mature for 1 h at T=25 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this powder are listed in table 1.

[0132] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, 34.4 g of 10% by weight hydrochloric acid is added together with as much demineralised water as is needed to impart a plastic behaviour to the kneading mass (about 70 g). This mixture is then kneaded for 30 minutes. Then, 24 g ammonia water (25% solution) is added and kneading continues for another 30 min. The kneaded mass is then passed through a 4 mm die by extrusion at a pressure of 40-70 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 400 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Example 2

[0133] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water until the conductivity in the filtrate is below 200 S/cm. The filter cake is redispersed and reacted with an aqueous solution of oxalic acid (corresponding to 8 g oxalic acid dihydrate to 92 g TiO.sub.2). This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0134] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, 16.4 g of 10% by weight hydrochloric acid is added together with as much demineralised water as is needed to impart a plastic behaviour to the kneading mass (about 94 g). This mixture is then kneaded for 30 minutes. Then, 11 g ammonia water (25% solution) and 44 ml demineralised water are added and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion at a pressure of 40-70 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

Example 3

[0135] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed and reacted with maleic acid while stirring (corresponding to 6 g maleic acid to 94 g TiO.sub.2). This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

Example 4

[0136] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed and reacted with citric acid monohydrate while stirring (corresponding to 6 g citric acid monohydrate to 94 g TiO.sub.2). This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0137] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, 32.8 ml of 10% by weight hydrochloric acid is added together with as much demineralised water as is needed to impart a plastic behaviour to the kneading mass (about 75 g). This mixture is then kneaded for 30 minutes. Then, 17.2 ml ammonia water (25% solution) is added and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion at a pressure of 40-70 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

Example 5

[0138] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed and reacted with tartaric acid (corresponding to 6 g tartaric acid to 94 g TiO.sub.2) while stirring. This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

Example 6

[0139] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed and reacted with triethanol amine (corresponding to 1 g triethanol amine to 99 g TiO.sub.2) while stirring. This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

Example 7

[0140] A commercially available titanium oxide hydrate suspension (TiO.sub.(2-x)(OH).sub.2x (0<x1)) with a Ti content of approx. 200 g TiO.sub.2/l calculated as titanium dioxide, an average particle size of 48 nm (measured by PCS measurement according to ultrasonic probe dispersion and having a specific surface area of 350 m.sup.2/g (N.sub.2 5 point BET, measured after drying at 105 C.) is used as the educt (e.g., Hombikat M310 Suspension, a commercial product manufactured by Sachtleben Chemie GmbH). This suspension is reacted with oxalic acid dihydrate (corresponding to 6 g oxalic acid dihydrate to 94 g TiO.sub.2) while stirring. This suspension is stirred for 24 h and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1

[0141] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH=6 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion at a pressure of 140-180 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

Example 8

[0142] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed and reacted with methyl cellulose solution (methyl cellulose 4000 P2) (corresponding to 0.5 g methyl cellulose to 99.5 g TiO.sub.2) while stirring. This suspension is allowed to mature for 2 h at T=50 C. and then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0143] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1.5 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH=5 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 450 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Example 9

[0144] A commercially available titanium oxide hydrate suspension (TiO.sub.(2-x)(OH).sub.2x (0<x1)) with a Ti content of approx. 300 g TiO.sub.2/l calculated as titanium dioxide, an average particle size of 950 nm (measured by PCS measurement according to ultrasonic probe dispersion and having a specific surface area of 350 m.sup.2/g (N.sub.2 5 point BET, measured after drying at 105 C.) is used as the educt (e.g., Hombikat M210 Suspension, a commercial product manufactured by Sachtleben Chemie GmbH). This suspension is adjusted to pH=3.8 with acetic acid while stirring. This suspension is then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1

[0145] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH=6 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 350 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Example 10

[0146] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed. Then, ammonia is added with stirring to adjust the pH value of the suspension to pH=6.9. This suspension is then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0147] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH=6 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 350 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Example 11

[0148] Hombikat MTSA (a commercial product manufactured by Sachtleben Chemie GmbH) is neutralised with caustic soda to a pH value of 6.5 and washed with water. The filter cake is redispersed. Then, nitric acid is added with stirring to adjust the pH value of the suspension to pH=3.2. This suspension is then spray dried, the product discharge temperature being T=110+/5 C. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0149] 400 g of the powder and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH=6 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 350 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Example 12

[0150] 400 g of the powder of Example 1 and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the Double-Z kneader and mixed for about 1 min. Then, 34 g of 10% by weight hydrochloric acid and 20 g of an acid titanium dioxide sol (HOMBIKAT XXS 100 a commercial product manufactured by Sachtleben Chemie GmbH) are added together with as much demineralised water as is needed to impart plastic behaviour to the kneaded mass (about 74 g). This mixture is then kneaded for 30 minutes. Then, 7.7 ml ammonia water (25% solution) is added and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion under a pressure of 120-150 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 400 C. over several hours and held at this temperature for 120 min before being cooled to room temperature

Example 13

[0151] 400 g of the powder of Example 1 and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the Double-Z kneader and mixed for about 1 min. Then, 34 g of 10% by weight hydrochloric acid and 30 g of an acid titanium dioxide sol (HOMBIKAT XXS 100 a commercial product manufactured by Sachtleben Chemie GmbH) are added together with as much demineralised water as is needed to impart plastic behaviour to the kneaded mass. This mixture is then kneaded for 30 minutes. Then, 7.4 ml ammonia water (25% solution) is added and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion under a pressure of 120-150 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then heated to 90 C. for 60 min, then heated to the calcining temperature of 350 C. over several hours and held at this temperature for 120 min before being cooled to room temperature.

Comparison Example 1

[0152] 400 g Hombikat M211 (titanium dioxide, a commercial product manufactured by Sachtleben) and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, 60 g of 10% by weight hydrochloric acid is added together with as much demineralised water as is needed to impart a plastic behaviour to the kneading mass (about 70 ml). This mixture is then kneaded for 30 minutes. Then, 20 g ammonia water (25% solution) and 20 ml demineralised water are added and kneading continues for 30 min. The kneaded mass is then passed through a 3 mm die by extrusion at a pressure of 40-70 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

Comparison Example 2

[0153] Hombikat MTSA (a commercial product manufactured by Sachtleben) is neutralised to a pH value of 6.6 with caustic soda and washed with water until the filtrate conductivity is <200 S/cm. The filter cake is redispersed and spray dried. The properties of this spray dried TiO.sub.2 or titanium oxide hydrate powder are listed in table 1.

[0154] 400 g of the powder are placed in the mixing trough of the double-Z kneader with 100 g oxalic acid (9.1% solution) and 64 g of an aqueous 2.5% solution of methyl cellulose and mixed for about 1 min. Then, 27 g of 10% by weight hydrochloric acid is added. This mixture is then kneaded for 30 minutes. Then, 12 g ammonia water (25% solution) and 35 ml demineralised water are added and kneading continues for another 30 min. The kneaded mass is then passed through a 3 mm die by extrusion at a pressure of 40-70 bar and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

Comparison Example 3

[0155] The typical properties of Hombikat M311 powder (titanium dioxide, a commercial product manufactured by Sachtleben) are listed in table it.

[0156] 400 g of Hombikat M311 (a commercial product manufactured by Sachtleben) and 64 g of an aqueous 2.5% solution of methyl cellulose are placed in the mixing trough of the double-Z kneader and mixed for about 1 min. Then, the pH value of the kneaded mass is adjusted to pH=1 by adding hydrochloric acid together with as much demineralised water as is needed to impart a plastic behaviour to the kneading mass. This mixture is then kneaded for 30 minutes. Then, the pH value of the kneaded mass is adjusted to pH =6 by adding ammonia water (25% solution) and kneading continues for another 30 min. The kneaded mass is then passed through a 1.8 mm die by extrusion and cut to the desired length (approx. 15-20 mm). The extrudates prepared in this way are initially air dried and then tempered as described in Example 1.

[0157] As shown in table 2, the surface-modified powders according the invention with high specific surface areas may be used to produce high strength extrudates which also have high specific surface areas and high pore volumes. Comparable TiO.sub.2-based powders with high specific surface areas are not known in the related art.

[0158] The improved strength of the extrudates due to the addition of auxiliary shaping agents before drying at the suspension stage is particularly surprising, since the addition of these same auxiliary shaping agents during the kneading process does not significantly affect the strength thereof, as is shown by comparison example 2.

TABLE-US-00001 TABLE 1 Powder properties Pore TiO.sub.2 C SO.sub.4 volume content content content Crystallite Spec. surface area (Total) [% by [% by [% by size Example (5 pt BET) [m.sup.2/g] [cm.sup.3/g] wgt.] wgt.] wgt.] [nm] Phase Comparison 346 0.31 88.9 0.15 0.78 7 Anatase example 1 Comparison 312 0.30 86.7 0.12 1.50 8 Anatase example 2 Comparison 354 0.81 84.8 n.d. 0.71 8 Anatase example 3 Example 1 333 0.32 84.4 0.79 1.3 8 Anatase Example 2 327 0.30 85.3 1.40 0.78 8 Anatase Example 3 320 0.30 85.2 2.3 n.d. n.d. Anatase Example 4 316 0.28 86.4 1.8 n.d. n.d. Anatase Example 5 328 0.30 84.9 1.8 n.d. n.d. Anatase Example 6 344 0.32 88.4 0.55 n.d. n.d. Anatase Example 7 351 0.78 77.1 0.85 0.39 8 Anatase Example 8 349 0.31 87.7 n.d. 0.3 n.d. Anatase Example 9 352 0.33 85.1 n.d. 0.31 n.d. Anatase Example 10 347 0.31 86.3 n.d. n.d. n.d. Anatase Example 11 339 0.32 87.2 n.d. 0.29 n.d. Anatase

TABLE-US-00002 TABLE 2 Extrudate properties Spec. surface Pore Avg. area (5 pt. volume pore Strength BET) (Total) diameter Example [N/mm] [m.sup.2/g] [cm.sup.3/g] [nm] Phase Comparison 5 106 0.29 11 Anatase example 1 Comparison 6 114 0.30 10 Anatase example 2 Comparison 4 126 0.50 16 Anatase example 3 Example 1 28 107 0.27 10 Anatase Example 2 23 108 0.26 10 Anatase Example 4 10 103 0.26 10 Anatase Example 7 10 130 0.50 16 Anatase Example 8 25 156 0.27 n.d. Anatase Example 9 20 232 0.25 n.d. Anatase Example 10 20 209 0.24 n.d. Anatase Example 11 11 126 0.24 n.d. Anatase Example 12 19 109 0.26 Anatase Example 13 37 260 0.27 Anatase