Chemistry of inorganic compounds – Rare earth compound
Reexamination Certificate
2007-01-23
2007-01-23
Bos, Steven (Department: 1754)
Chemistry of inorganic compounds
Rare earth compound
C502S302000, C502S303000, C502S304000
Reexamination Certificate
active
10402808
ABSTRACT:
A homogeneous ceria-based mixed-metal oxide, useful as a catalyst support, a co-catalyst and/or a getter has a relatively large surface area per weight, typically exceeding 150 m2/g, a structure of nanocrystallites having diameters of less than 4 nm, and including pores larger than the nanocrystallites and having diameters in the range of 4 to about 9 nm. The ratio of pore volumes, VP, to skeletal structure volumes, VS, is typically less than about 2.5, and the surface area per unit volume of the oxide material is greater than 320 m2/cm3, for low internal mass transfer resistance and large effective surface area for reaction activity. The mixed metal oxide is ceria-based, includes Zr and or Hf, and is made by a novel co-precipitation process. A highly dispersed catalyst metal, typically a noble metal such as Pt, may be loaded on to the mixed metal oxide support from a catalyst metal-containing solution following a selected acid surface treatment of the oxide support. Appropriate ratioing of the Ce and other metal constituents of the oxide support contribute to it retaining in a cubic phase and enhancing catalytic performance. Rhenium is preferably further loaded on to the mixed-metal oxide support and passivated, to increase the activity of the catalyst. The metal-loaded mixed-metal oxide catalyst is applied particularly in water gas shift reactions as associated with fuel processing systems, as for fuel cells.
REFERENCES:
patent: 3565830 (1971-02-01), Keith et al.
patent: 3825501 (1974-07-01), Muenger
patent: 3870455 (1975-03-01), Hindin
patent: 4021366 (1977-05-01), Robin et al.
patent: 4157316 (1979-06-01), Thompson et al.
patent: 4170573 (1979-10-01), Ernest et al.
patent: 4171288 (1979-10-01), Keith et al.
patent: 4297246 (1981-10-01), Cairns et al.
patent: 4308176 (1981-12-01), Kristiansen
patent: 4331565 (1982-05-01), Schaefer et al.
patent: 4476246 (1984-10-01), Kim et al.
patent: 4585752 (1986-04-01), Ernest
patent: 4587231 (1986-05-01), Sawamura et al.
patent: 4629612 (1986-12-01), van der Wal et al.
patent: 4835132 (1989-05-01), Sambrook
patent: 4868148 (1989-09-01), Henk et al.
patent: 5039503 (1991-08-01), Sauvion et al.
patent: 5057483 (1991-10-01), Wan
patent: 5073532 (1991-12-01), Domesle et al.
patent: 5139992 (1992-08-01), Tauster et al.
patent: 5254519 (1993-10-01), Wan et al.
patent: 5275997 (1994-01-01), Ganguli et al.
patent: 5464606 (1995-11-01), Buswell et al.
patent: 5480854 (1996-01-01), Rajaram et al.
patent: 5490977 (1996-02-01), Wan et al.
patent: 5491120 (1996-02-01), Voss et al.
patent: 5492878 (1996-02-01), Fujii et al.
patent: 5500198 (1996-03-01), Liu et al.
patent: 5516597 (1996-05-01), Singh et al.
patent: 5532198 (1996-07-01), Chopin et al.
patent: 5744118 (1998-04-01), Imamura et al.
patent: 5788950 (1998-08-01), Imamura et al.
patent: 5830425 (1998-11-01), Schneider et al.
patent: 5895772 (1999-04-01), Grigorova et al.
patent: 5945369 (1999-08-01), Kimura et al.
patent: 5948683 (1999-09-01), Koermer et al.
patent: 5990040 (1999-11-01), Hu et al.
patent: 6033634 (2000-03-01), Koga
patent: 6040265 (2000-03-01), Nunan
patent: 6107240 (2000-08-01), Wu et al.
patent: 6120923 (2000-09-01), Van Dine et al.
patent: 6120925 (2000-09-01), Kawatsu et al.
patent: 6133194 (2000-10-01), Cuif et al.
patent: 6159256 (2000-12-01), Bonville, Jr. et al.
patent: 6204219 (2001-03-01), Brezny et al.
patent: 6299994 (2001-10-01), Towler et al.
patent: 6322917 (2001-11-01), Acker
patent: 6326329 (2001-12-01), Nunan
patent: 6409939 (2002-06-01), Abdo et al.
patent: 2001/0002248 (2001-05-01), Ukai et al.
patent: 2002/0071806 (2002-06-01), Sabacky et al.
patent: 2002/0073895 (2002-06-01), Barnes et al.
patent: 2002/0110519 (2002-08-01), Ying et al.
patent: 0298351 (1989-01-01), None
patent: 1 046 612 (2000-10-01), None
patent: 1 256 545 (2001-07-01), None
patent: 1 161 991 (2001-12-01), None
patent: 10202101 (1998-08-01), None
patent: 1133294 (1999-12-01), None
patent: WO 96/23573 (1996-08-01), None
patent: WO 97/44123 (1997-11-01), None
patent: WO 01/03828 (2001-01-01), None
Pengpanich, et al., “Catalytic oxidation of methan over . . . urea hydrolysis” Applied Catalysis A: General 234, pp. 221-233, 2002, no month.
Lin et al., “Coprecipitation and hydrothermal synthesis of ultrafine 5.5 mol% CeO2-2 mol% YO1.5-ZrO2 powders” Jan. 1997, J. Am Ceram. Soc. 80(1), pp. 92-98.
S. Hilaire, “A comparative study of water-gas shift reaction over ceria supported metallic catalysts”, Applied Catalysis A: General 215 (2001), pp. 271-278.
Qi Fu, “Nanostructured Au-CeO2 catalysts for low-temperature water-gas shift”, Catalysis Letters, vol. 77, No. 1-3, (2001), pp. 87-95.
Yue Li, et al, “Low-temperature water-gas shift reaction over Cu- and Ni-loaded cerium oxide cataysts,” Applied Catalysis B: Environmental 27 (2000), pp. 179-191.
A. Martinez-Arias, et al, “EPR study on oxygen handling properties of ceria, zirconia, and Zr-Ce (1:1) mixed oxide samples”, Catalysis Letters, 65 (2000), pp. 197-204.
E. S. Putna, et al, “Ceria films on zirconia substrates: models for understanding oxygen storage properties”, Catalysis Today, 50 (1999), pp. 343-352.
Paolo Fornasiero, et al. “On the rate determining step in the reduction of CeO2-ZrO2 mixed oxides”, Applied Catalysis B: Environmental, 22 (1999), pp. L11-L14.
S. Rossignol, et al, “Preparation of zirconia-ceria materials by soft chemistry”, Catalysis Today, 50 (1999), pp. 261-270.
T. Bunluesin, et al, “Studies of the water-gas shift reaction on ceria-supported Pt, Pd, and Rh: implications for oxygen storage proerties”, Applied Catalysis, B: Environmental, (1998), pp. 107-114.
G. Colon, et al, “Surface and structural characterization of CeZr1-xO2 CEZIRENCAT mixed oxides as potential three-way catalyst promoters”, J. Chem. Soc., Faraday Trans., 94 (1998), pp. 3717-3726.
O. A. Kirichenko, et al, “Effect of coprecipitation conditions on the surface area, phase composition, and reducibility of Ce2-ZrO2-Y203 materials for automotive three-way catalysts”, Preparation of Catalysts VII, B. Delmon, et al, editors, (1998), pp. 411-420.
Carla E. Hori, et al, “Thermal stability of oxygen storage properties in a mixed CeO2-ZrO2 system”,Applied Catalysis B: Environmental, 16 (1998), pp. 105-111.
Lj. Kundakovic, et al, “Cu- and Ag-modified cerium oxide catalysts for methane oxidation”,Journal of Catalysis179 (1998), pp. 203-221.
DanielaTerribile, et al, “The preparation of high surface area CeO2-ZrO2 mixed oxides by a surfactant-assisted approach”,Catalysis Today, 43 (1998), pp. 79-88.
Lj. Kundakovic, et al, “Reduction characteristics of copper oxide in cerium and zirconium oxide systems”,Applied Catalysis A: General, 171 (1998), pp. 13-29.
G. Vlaic, et al, “Relationship between the zirconia-promoted reduction in the Rh-loaded Ce0.5Zr0.5O2 mixed oxide and the Zr-O local structure”,Journal of Catalysis168 (1997), pp. 386-392.
Polona Vidmar, et al, “Effects of trivalent dopants on the redox properties of Ce0.6Zr0.4O2 mixed oxide”,Journal of Catalysis171 (1997), pp. 160-168.
H. Cordatos, et al, “Effect of ceria structure on oxygen migration for Rh/ceria catalysts”,J. of Physical Chemistry, (1996) 100, pp. 785-789.
P. Fornasiero, et al, “Modification of the redox behaviour of CeO2 induced by structural doping with ZrO2”,J. of Catalysis164 (1996), pp. 173-183.
Yuhan Sun, et al, “Importance of homogeneity in the stabilisation of high surface area CeO2-ZrO2 aerogels”,J. of Material Chemistry6(6) (1996), pp. 1025-1029.
P. Fornasiero, et al, “Rh-loaded CeO2-ZrO2 solid solutions as highly eficient oxygen exchangers: dependence of the reduction behavior and the oxygen storage capacity on the structural properties”,J. of Catalysis151 (1995), pp. 168-177.
Luccini, E. et al, “Preparation of Zirconia-Ceria Powders by Coprecipitation . . . With Urea”, Int
Dardas Zissis
Feng Fangxia
Laube Bruce Leon
Leffler Miriam P.
Newman Caroline A.
Bos Steven
Schneeberger Stephen A.
UTC Fuel Cells LLC
LandOfFree
Ceria-based mixed-metal oxide structure, including method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Ceria-based mixed-metal oxide structure, including method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ceria-based mixed-metal oxide structure, including method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3821232