Ceramic materials for 4-way and NOx adsorber and method for making same

• US 20080203627A1
• Filed: 02/27/2007
• Published: 08/28/2008
• Est. Priority Date: 02/27/2007
• Status: Active Grant

• Current Assignee: Corning Incorporated
• Original Assignee: Corning Incorporated
• Inventors: Ogunwumi, Steven Bolaji, Tanner, Cameron Wayne
• Granted Patent: US 7,713,897 B2
• Time in Patent Office: Days
• US Class Current: 264/638
• CPC Class Codes: C04B 2111/00793 as filters or diaphragms
• CPC Class Codes: C04B 2111/0081 as catalysts or catalyst carriers
• CPC Class Codes: C04B 2111/325 the expansion being inhibited in one direction only
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3244 Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/447 Phosphates or phosphites, e.g. orthophosphate or hypophosphite
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 2235/9607 Thermal properties, e.g. thermal expansion coefficient
• CPC Class Codes: C04B 35/478 based on aluminium titanates
• CPC Class Codes: C04B 35/49 containing also titanium oxides or titanates
• CPC Class Codes: C04B 35/62675 characterised by the treatment temperature
• CPC Class Codes: C04B 38/0006 Honeycomb structures from one or more corrugated sheets by winding or stacking C04B38/0083
• CPC Class Codes: C04B 38/0054 the pores being microsized or nanosized
• CPC Class Codes: C04B 38/0074 expressed as porosity percentage
• CPC Class Codes: C04B 38/0645 Burnable, meltable, sublimable materials

Abstract

Disclosed are ceramic articles comprising a sintered phase ceramic composition containing, as expressed on a weight percent oxide basis: a(Al₂TiO₅)+b(ZrTiO₄)+c(Y₂O₃)+d(YPO₄) wherein “a, b, c, and d” represent weight fractions of each component such that (a+b+c+d)=1.00 and wherein 0.5<a≦0.95; 0≦b≦0.5, 0.0≦c≦0.10, and 0≦d≦0.5. Also disclosed are precursor batch compositions and methods for manufacturing the ceramic articles disclosed herein.

Claims

1. A ceramic article, comprising a sintered phase ceramic composition containing, as expressed on a weight percent oxide basis:

a(Al₂TiO₅)+b(ZrTiO₄)+c(Y₂O₃)+d(YPO₄)

wherein a, b, c, and d are weight fractions of each component such that (a+b+c+d)=1.00, and

wherein 0.5<

a≦

0.95;

0≦

b≦

0.5, 0.0≦

c≦

0.10, and 0≦

d≦

0.5.

2. The ceramic article of claim 1, wherein the sintered phase ceramic composition consists essentially of aluminum titanate, zirconium titanate, and yttrium oxide, and wherein 0.60≦

a≦

0.80 and 0.20≦

b≦

0.40 and 0.00≦

c≦

0.05.

3. The ceramic article of claim 1, wherein the sintered phase ceramic composition consists essentially of aluminum titanate and yttrium phosphate, wherein 0.5≦

a≦

0.95 and 0.05≦

d≦

0.5.

4. The ceramic article of claim 1, wherein the sintered phase ceramic composition has a total porosity greater than or equal to 45%.

5. The ceramic article of claim 4, wherein the sintered phase ceramic composition has a total porosity greater than or equal to 50%.

6. The ceramic article of claim 4, wherein the sintered phase ceramic composition has a total porosity in the range of from 50% to 60%.

7. The ceramic article of claim 1, wherein the sintered phase ceramic composition has a coefficient of thermal expansion in at least one direction that is less than or equal to 15.0×

10<sup>−

7</sup>/°

C. across the temperature range of from 25°

C. to 1000°

C.

8. The ceramic article of claim 1, wherein the sintered phase ceramic composition has a coefficient of thermal expansion in at least one direction that is less than or equal to 12.0×

10<sup>−

7</sup>/°

C. across the temperature range of from 25°

C. to 1000°

C.

9. The ceramic article of claim 1, wherein the sintered phase ceramic composition has a coefficient of thermal expansion in at least one direction that is less than or equal to 10.0×

10<sup>−

7</sup>/°

C. across the temperature range of from 25°

C. to 1000°

C.

10. The ceramic article of claim 1, wherein the sintered phase ceramic composition has a coefficient of thermal expansion in at least one direction that is less than or equal to 20.0×

10<sup>−

7</sup>/°

C. across the temperature range of from 25°

C. to 1000°

C. after aging in steam at 850°

C. for 10 hours.

11. The ceramic article of claim 1, further comprising an alkali catalyst washcoating.

12. The ceramic article of claim 1, wherein the alkali catalyst washcoating comprising potassium.

13. The ceramic article of claim 1, wherein the ceramic article is a honeycomb body.

14. A method for producing a ceramic article, comprising the steps of:

providing a plasticized ceramic precursor batch composition containing an alumina source, a titania source, and at least one of a zirconia source, a yttria source, a phosphate source, and a yttrium phosphate source;

an organic binder; and

a liquid vehicle;

forming an extruded green body from the plasticized ceramic precursor batch composition; and

firing the formed green body under conditions effective to convert the ceramic precursor composition into a sintered phase ceramic composition.

15. The method of claim 14, wherein the inorganic batch composition comprises an alumina source, a titania source, and a zirconia source.

16. The method of claim 15, wherein the inorganic batch composition further comprises an yttrium oxide sintering aid.

17. The method of claim 14, wherein the inorganic batch composition comprises an alumina source, a titania source, and a yttrium phosphate source.

18. The method of claim 14, further comprising the step of drying the formed green body prior to firing the green body.

19. The method of claim 14, wherein the firing conditions effective to convert the ceramic precursor composition into a sintered phase ceramic composition comprise firing the formed green body at a temperature in the range of from 1400°

C. to 1600°

C.

20. The method of claim 19, wherein the firing conditions effective to convert the ceramic precursor composition into a sintered phase ceramic composition comprise firing the formed green body at a temperature in the range of from 1450°

C. to 1550°

C.

21. The method of claim 18, wherein after firing substantially no titania remains unreacted.

22. The method of claim 14, wherein the extruded green body is a honeycomb body.