WO2007145145A1 - 無機酸化物、及びそれを用いた排ガス浄化用触媒 - Google Patents
無機酸化物、及びそれを用いた排ガス浄化用触媒 Download PDFInfo
- Publication number
- WO2007145145A1 WO2007145145A1 PCT/JP2007/061659 JP2007061659W WO2007145145A1 WO 2007145145 A1 WO2007145145 A1 WO 2007145145A1 JP 2007061659 W JP2007061659 W JP 2007061659W WO 2007145145 A1 WO2007145145 A1 WO 2007145145A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- oxide
- inorganic oxide
- aluminum
- metal
- lanthanum
- Prior art date
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- 229910052809 inorganic oxide Inorganic materials 0.000 title claims abstract description 161
- 239000003054 catalyst Substances 0.000 title claims description 65
- 238000000746 purification Methods 0.000 title description 25
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims abstract description 75
- 239000011164 primary particle Substances 0.000 claims abstract description 65
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 52
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 52
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 35
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 35
- 239000002245 particle Substances 0.000 claims abstract description 35
- 229910052751 metal Inorganic materials 0.000 claims abstract description 31
- 239000002184 metal Substances 0.000 claims abstract description 29
- 239000002344 surface layer Substances 0.000 claims abstract description 15
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 13
- 239000000654 additive Substances 0.000 claims description 105
- 230000000996 additive effect Effects 0.000 claims description 105
- 229910052746 lanthanum Inorganic materials 0.000 claims description 60
- 229910052779 Neodymium Inorganic materials 0.000 claims description 49
- 239000010948 rhodium Substances 0.000 claims description 31
- 229910052703 rhodium Inorganic materials 0.000 claims description 28
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 28
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 16
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 16
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 6
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 6
- 229910052791 calcium Inorganic materials 0.000 claims description 6
- 229910052727 yttrium Inorganic materials 0.000 claims description 6
- 229910052788 barium Inorganic materials 0.000 claims description 4
- 229910052749 magnesium Inorganic materials 0.000 claims description 4
- 229910052684 Cerium Inorganic materials 0.000 claims description 3
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 3
- 229910052693 Europium Inorganic materials 0.000 claims description 3
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 3
- 229910052689 Holmium Inorganic materials 0.000 claims description 3
- 229910052772 Samarium Inorganic materials 0.000 claims description 3
- 229910052712 strontium Inorganic materials 0.000 claims description 3
- 229910052691 Erbium Inorganic materials 0.000 claims description 2
- 229910052771 Terbium Inorganic materials 0.000 claims description 2
- 229910052775 Thulium Inorganic materials 0.000 claims description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 51
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 40
- 239000007789 gas Substances 0.000 description 39
- 239000000203 mixture Substances 0.000 description 37
- 239000000243 solution Substances 0.000 description 31
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 27
- 229910052726 zirconium Inorganic materials 0.000 description 27
- 230000000052 comparative effect Effects 0.000 description 19
- 238000010304 firing Methods 0.000 description 17
- 230000003197 catalytic effect Effects 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 10
- GJKFIJKSBFYMQK-UHFFFAOYSA-N lanthanum(3+);trinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O GJKFIJKSBFYMQK-UHFFFAOYSA-N 0.000 description 10
- VQVDTKCSDUNYBO-UHFFFAOYSA-N neodymium(3+);trinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Nd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VQVDTKCSDUNYBO-UHFFFAOYSA-N 0.000 description 10
- -1 Ding b Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 9
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 9
- 239000002131 composite material Substances 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 230000003993 interaction Effects 0.000 description 7
- 239000010410 layer Substances 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- XNDZQQSKSQTQQD-UHFFFAOYSA-N 3-methylcyclohex-2-en-1-ol Chemical compound CC1=CC(O)CCC1 XNDZQQSKSQTQQD-UHFFFAOYSA-N 0.000 description 5
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 5
- 239000011575 calcium Substances 0.000 description 5
- 239000001257 hydrogen Substances 0.000 description 5
- 229910052739 hydrogen Inorganic materials 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910017604 nitric acid Inorganic materials 0.000 description 5
- 239000002243 precursor Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000011777 magnesium Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- 239000000706 filtrate Substances 0.000 description 3
- CFYGEIAZMVFFDE-UHFFFAOYSA-N neodymium(3+);trinitrate Chemical compound [Nd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O CFYGEIAZMVFFDE-UHFFFAOYSA-N 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000011163 secondary particle Substances 0.000 description 3
- 238000000629 steam reforming Methods 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- GEIAQOFPUVMAGM-UHFFFAOYSA-N Oxozirconium Chemical compound [Zr]=O GEIAQOFPUVMAGM-UHFFFAOYSA-N 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 150000001768 cations Chemical class 0.000 description 2
- 238000000975 co-precipitation Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000009616 inductively coupled plasma Methods 0.000 description 2
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 150000002910 rare earth metals Chemical class 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000011343 solid material Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229910052765 Lutetium Inorganic materials 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 230000014509 gene expression Effects 0.000 description 1
- 230000009036 growth inhibition Effects 0.000 description 1
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000010954 inorganic particle Substances 0.000 description 1
- 150000002500 ions Chemical group 0.000 description 1
- OHSVLFRHMCKCQY-UHFFFAOYSA-N lutetium atom Chemical compound [Lu] OHSVLFRHMCKCQY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- SJLOMQIUPFZJAN-UHFFFAOYSA-N oxorhodium Chemical compound [Rh]=O SJLOMQIUPFZJAN-UHFFFAOYSA-N 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910003450 rhodium oxide Inorganic materials 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 229910052706 scandium Inorganic materials 0.000 description 1
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 1
- 229910052814 silicon oxide Inorganic materials 0.000 description 1
- 239000007962 solid dispersion Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
- 230000008719 thickening Effects 0.000 description 1
- FRNOGLGSGLTDKL-UHFFFAOYSA-N thulium atom Chemical compound [Tm] FRNOGLGSGLTDKL-UHFFFAOYSA-N 0.000 description 1
- NAWDYIZEMPQZHO-UHFFFAOYSA-N ytterbium Chemical compound [Yb] NAWDYIZEMPQZHO-UHFFFAOYSA-N 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B13/00—Oxygen; Ozone; Oxides or hydroxides in general
- C01B13/14—Methods for preparing oxides or hydroxides in general
- C01B13/36—Methods for preparing oxides or hydroxides in general by precipitation reactions in aqueous solutions
- C01B13/363—Mixtures of oxides or hydroxides by precipitation
-
- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/56—Platinum group metals
- B01J23/63—Platinum group metals with rare earths or actinides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
-
- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
-
- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/56—Platinum group metals
- B01J23/58—Platinum group metals with alkali- or alkaline earth metals
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G23/00—Compounds of titanium
- C01G23/04—Oxides; Hydroxides
- C01G23/047—Titanium dioxide
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- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G25/00—Compounds of zirconium
- C01G25/02—Oxides
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01D2255/20—Metals or compounds thereof
- B01D2255/202—Alkali metals
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- B01D2255/204—Alkaline earth metals
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- B01D2255/20—Metals or compounds thereof
- B01D2255/206—Rare earth metals
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- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
- B01D2255/407—Zr-Ce mixed oxides
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- 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
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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- B01J35/40—
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- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/0201—Impregnation
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/03—Precipitation; Co-precipitation
- B01J37/031—Precipitation
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- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
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- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/50—Solid solutions
- C01P2002/52—Solid solutions containing elements as dopants
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
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- 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
- C01P2006/32—Thermal properties
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to an inorganic oxide and an exhaust gas-purifying catalyst using the same.
- Exhaust gas purification catalysts used for purification of exhaust gas from internal combustion engines or the like are required to have extremely high heat resistance in order to maintain high catalytic activity even when used at high temperatures for a long period of time. ing.
- an exhaust gas purifying catalyst for example, a catalyst in which a metal having catalytic activity is supported on a carrier made of a particulate metal oxide is known.
- Japanese Patent Application Laid-Open No. 05-285386 discloses that a rare earth element oxide is uniformly dissolved in oxidized dinoleum oxide particles.
- a catalyst using a catalyst as a support is disclosed.
- JP-A-09-141098 discloses a catalyst using a combination of an oxide of an oxide of a rare earth and an oxide of a rare earth element as a carrier.
- a particulate inorganic oxide containing one of the additive elements, the content ratio power of the aluminum oxide The total amount of the aluminum in the aluminum oxide, the metal element in the metal oxide, and the additive element 15% to 40% by mole (30 to 80at% as an element), and the primary particle of the inorganic oxide has a particle diameter of 80% or more and a force SlOOnm or less, and at least a part of the primary particles.
- an inorganic oxide having a surface concentrated region in which the content of the additive element is locally increased in the surface layer portion.
- Oxide In terms of the total amount of the inorganic oxide when converted to the amount of:! To 5% by mass of the additive Inorganic oxides that are present are described.
- a catalyst using an inorganic oxide as described in Document 3 as a support has a relatively high heat resistance because the heat resistance of the support is improved, but the heat resistance point is high. However, it was not always enough.
- the present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide an inorganic oxide having excellent heat resistance, and an exhaust gas purifying catalyst using the inorganic oxide.
- the conventional catalyst as described in the above-mentioned Document 3 generally has a basic property that is considered to improve heat resistance. It became clear that the content ratio of additive elements and the content ratio of aluminum oxide were not necessarily in the proper ranges.
- the present inventors have found that a metal oxide that does not form a composite oxide of aluminum oxide and aluminum oxide, and a specific additive element.
- the inorganic oxide containing the additive element so as to locally have a high concentration in the surface layer portion of the primary particles of the inorganic oxide.
- the content ratio of aluminum oxide is adjusted to a specific range, and the amount of the additive element in the region where the additive element is locally high in concentration (surface concentration region) is adjusted to an appropriate range.
- the inorganic oxide of the present invention includes at least one additive selected from the group consisting of aluminum oxide, a metal oxide that does not form a composite oxide of aluminum oxide, and a rare earth element and an alkaline earth element.
- the primary particles of the inorganic oxide have a particle diameter of lOOnm or less, and at least a part of the primary particles contains the content of the additive element in the surface layer portion.
- the surface has a locally enhanced surface enriched region, and
- the amount of the additive element in the surface enriched region is 0.06 to 0.98 mass% in terms of oxide with respect to the total amount of the inorganic oxide.
- the metal oxide contains at least dinole oxide.
- the metal oxide is ZrO, ZrO—CeO.
- it contains at least one oxide.
- the additive element is Y, La, Pr, Nd, Sm, Eu, Gd, Ding b, Dy, Ho, Er, Ding m, Yb, Lu, Mg From Y, La, Pr, Nd, Yb, Mg, Ca, Ba, it is preferable that the element force is at least one element selected from Ca, Sr, Ba, Sc, Ce force More preferably, it is at least one element selected from the group consisting of at least one element selected from the group consisting of La and Nd.
- the exhaust gas purifying catalyst of the present invention is formed by supporting rhodium on the inorganic oxide.
- each primary particle contains the additive element in a proportion of the above-mentioned specific range, thereby improving the phase stability and crystal stability of each primary particle itself under a high temperature environment.
- a surface concentrated region in which the content ratio of the additive element is locally increased is formed in the surface layer portion of the primary particles constituting the inorganic particles.
- the region where the content ratio of the additive element is increased is formed so as to cover the surface of the primary particles.
- this surface enriched region does not necessarily need to completely cover the surface of the primary particles. It is only necessary to cover at least a part of the surface of the primary particles.
- the additive element as described above has basicity when it becomes an oxide, so when rhodium (Rh) is supported, it is represented by Rh-OM (M is an additive element in the carrier). Generate a bond.
- the supported rhodium particles are difficult to move, thereby effectively suppressing the grain growth of rhodium.
- the primary particles contain additional elements in the inner layer part (inner layer part) rather than the surface concentrated region only in the surface layer part, but the content ratio of the rare earth element over the entire primary particle including the inner layer part that is locally localized.
- the content ratio of aluminum oxide in the inorganic oxide and the amount of the additive element in the surface concentration region are adjusted to appropriate ranges, respectively. Therefore, the present inventors speculate that the above-described effects are sufficiently exhibited and excellent heat resistance can be achieved.
- the inorganic oxide of the present invention includes at least one additive element selected from the group consisting of a metal oxide that does not form a composite oxide of aluminum oxide and aluminum oxide, and a rare earth element and an alkaline earth element.
- the content ratio of the aluminum oxide is 48 to 92 at% as an element with respect to the total amount of the aluminum in the aluminum oxide, the metal element in the metal oxide, and the additive element,
- the primary particles of the inorganic oxide have a particle size of lOOnm or less, and at least a part of the primary particles has a locally increased content of the additive element in the surface layer portion. Having a thickened surface area, and The amount of the additive element in the surface enriched region is 0.06 to 0.98 mass% in terms of oxide with respect to the total amount of the inorganic oxide.
- the inorganic oxide of the present invention is an inorganic oxide containing aluminum oxide, a metal oxide described later, and an additive element described later.
- aluminum oxide Al 2 O 3
- the content ratio power of aluminum oxide is 48 to 92at as an element with respect to the total amount of aluminum in aluminum oxide, metal elements in metal oxide described later, and additive elements described later. Must be in the% range. If the aluminum oxide content is less than 48 at%, the heat resistance of the resulting inorganic oxide is insufficient. On the other hand, when it exceeds 92 at%, the steam reforming reaction activity is lowered when rhodium is supported as a catalyst. In addition, from the viewpoint of heat resistance as a carrier of the obtained inorganic oxide, the aluminum oxide content is preferably in the range of 55 to 90 at%.
- the metal oxide according to the present invention is an oxide that does not form a composite oxide with aluminum oxide, and in combination with aluminum oxide, the metal oxide is a primary oxide composed of a composite oxide that is substantially uniformly dissolved or dispersed in each other. It is an oxide that does not form particles.
- such a metal oxide contains primary particles mainly composed of aluminum oxide when a coprecipitate obtained by coprecipitation of a hydroxide as a precursor and aluminum hydroxide is calcined. Is an oxide that separately forms primary particles. Therefore, the inorganic oxide of the present invention contains primary particles mainly composed of aluminum oxide and primary particles mainly composed of a metal oxide other than aluminum oxide. Thus, it can be confirmed by the analytical method described later that each primary particle is formed separately.
- Examples of such metal oxides include zirconium oxide (ZrO 2), silicon oxide (Si 0), and
- TiO 2 2 Contains at least one oxide selected from the group consisting of titanium oxide (TiO 2).
- ZrO, ZrO- CeO, ZrO are preferred which contain at least zirconium oxide from the viewpoint of obtaining a catalyst with particularly excellent heat resistance and catalytic activity when combined with rhodium as a catalytic metal.
- YO, ZrO—La ⁇ At least one oxide selected from the group consisting of ZrO-NdO and ZrO-PrO forces
- the inclusion is more preferable.
- the content ratio of such a metal oxide is 2 as an element with respect to the total amount of the metal element in the metal oxide, the aluminum in the aluminum oxide and the additive element described later. It is preferably in the range of 7 to 51. lat%, more preferably in the range of 10 to 40 at%.
- the content ratio of the metal oxide is less than the lower limit, the steam reforming reaction activity tends to decrease when rhodium is supported and used as a catalyst.
- the above upper limit is exceeded, the heat resistance of the carrier itself is lowered, and the growth of rhodium cannot be sufficiently suppressed.
- the additive element according to the present invention is at least one element selected from the group consisting of rare earth elements and alkaline earth elements.
- additive elements include yttrium ( ⁇ ), lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), Terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), magnesium (Mg), calcium (Ca), strontium (Sr) , Barium (Ba), scandium (Sc), and cerium (Ce) can be preferably used.
- Y, La, Pr, Nd, Yb, Mg, Ca, and Ba are more preferable from the viewpoint of heat resistance as a carrier of the obtained inorganic oxide, and La and Nd are particularly preferable.
- These additive elements can be used alone or in combination of two or more.
- different additive elements may be included in the inorganic oxide in the surface enrichment region described later and other regions.
- such an additive element exists in a state of solid solution, dispersion, or the like with respect to aluminum oxide or the metal oxide.
- at least a part of the additive element is oxidized in the inner layer portion of the primary particles of the inorganic oxide (portion other than the surface concentration region described later) in order to make the effect of the present invention due to the additive element more prominently.
- It is preferably dissolved in aluminum or the metal oxide. In this case, it is more preferable that both the aluminum oxide and the metal oxide have the additive element as a solid solution.
- the content ratio of such an additive element in the aluminum oxide is preferably in the range of 1 ⁇ :! to 8 ⁇ Oat% with respect to the total amount of aluminum, metal elements in the metal oxide, and additive elements. More preferably, it is in the range of%. If the content of the additive element is less than the lower limit, the catalyst metal grain growth tends not to be sufficiently suppressed under a high temperature environment. On the other hand, when the above upper limit is exceeded, the interaction with the catalyst metal becomes excessively strong and the catalytic activity tends to decrease.
- the inorganic oxide of the present invention is a particulate inorganic oxide containing the above-described aluminum oxide, metal oxide, and additive element. Further, 80% or more of the primary particles of such inorganic oxides must have a particle size of 10 Onm or less in order to increase the specific surface area and increase the catalytic activity. . Further, the proportion of primary particles having a particle size of lOOnm or less is more preferably 90% or more, and more preferably 95% or more. This particle diameter is the largest diameter that can be defined for one particle. Further, the average particle diameter of the primary particles in the whole particulate inorganic oxide is preferably 3 to 40 nm, more preferably:! To 50 nm.
- the secondary particles formed by agglomerating primary particles of such inorganic oxides are mainly primary particles composed of aluminum oxide and having a particle diameter of lOOnm or less, and mainly other than aluminum oxide. It is preferably formed by agglomeration of primary particles made of a metal oxide with a particle diameter of lOOnm or less.
- primary particles mainly composed of aluminum oxide mean primary particles formed mainly from aluminum oxide. Specifically, it is preferable that the particles mainly made of aluminum oxide are composed of aluminum oxide at least half of the whole in terms of molar ratio or mass ratio. Further, similar expressions such as “primary particles mainly composed of metal oxide” and “primary particles mainly composed of dinolecon oxide” mean the same contents as described above.
- composition of the primary particle size and the aggregation state of the secondary particles are as follows: TEM (Transmission Electron Microscope), SEM (Scanning Electron Microscope), FE—STEM (Field Emission—Scanning). Transmission electron microscope), EDX (energy dispersive X-ray detector), XPS (photoelectric)
- TEM Transmission Electron Microscope
- SEM Scanning Electron Microscope
- FE Field Emission—Scanning
- Transmission electron microscope
- EDX energy dispersive X-ray detector
- XPS photoelectric
- the primary particles constituting the inorganic oxide has a surface concentration region in which the content ratio of the additive element is locally increased in the surface layer portion. is necessary. It is preferable that substantially all of the primary particles constituting the inorganic oxide containing the additive element have such a surface concentrated region, but the effects of the present invention are not significantly impaired. To the extent, primary particles that do not have a surface-enriched region are mixed, but they can be mixed.
- the content ratio of the additive element in the surface concentration region may be relatively increased with respect to the content ratio in the region on the inner layer side in the particle.
- a surface-enriched region is formed so as to cover the surface of the primary particles while having a certain depth, but it is not always necessary to completely cover the entire surface of the primary particles.
- the content ratio of the additive element in the primary particles is gradually increased from the inner layer side toward the surface layer side. Therefore, a clear boundary is not necessarily formed between the surface enriched region and the particle central portion on the deeper side.
- the additive element in such a surface enriched region is present in the surface layer portion of the primary particles of the inorganic oxide.
- the amount of the additive element in the surface concentration region needs to be 0.06-0.98% by mass with respect to the total amount of the inorganic oxide. If the amount of the additive element in the surface concentration region is less than 0.06% by mass, the interaction between the additive element and the catalyst metal such as rhodium is insufficient, so that an inorganic oxide having excellent heat resistance can be obtained. I can't get it. On the other hand, if it exceeds 0.98 mass%, the interaction with the catalyst metal is too strong, and thus the catalytic activity decreases when the obtained inorganic oxide is used as a support.
- the additive element in the surface concentration region is eluted when it comes into contact with an acidic solution such as an aqueous nitric acid solution. Therefore, the amount of additive element present in the surface concentration region can be confirmed by quantifying the amount of additive element eluted in the aqueous nitric acid solution when the inorganic oxide is brought into contact with the aqueous nitric acid solution. More specifically, for example, 10 ml of inorganic oxide 0.lg This is added to the IN nitric acid aqueous solution, and this is stirred for 2 hours to elute the additive elements present in the surface enriched region, and the amount of the added additive element is quantified by chemical analysis, thereby adding to the surface concentrated region. The amount of potassium element can be confirmed.
- the surface enriched region is formed in the primary particles of the inorganic oxide, in addition to the above-described method of elution of additive elements, for example, EDX, SIMS (secondary ion mass spectrometer ) Etc., and can be confirmed by comparing the content ratio of the additive element in the primary particle surface layer portion and the central portion.
- additive elements for example, EDX, SIMS (secondary ion mass spectrometer ) Etc.
- the composition of the entire inorganic oxide is analyzed by ICP (high frequency plasma emission analyzer) or the like, and the content ratio of the additive element as the average value of the entire inorganic oxide is determined. It may be quantified to confirm that the content of the additive element in the surface layer is higher than this.
- the inorganic oxide as described above is selected from the group consisting of, for example, aluminum, a metal element that does not form a complex oxide with aluminum oxide when it becomes an oxide, and a rare earth element and an alkaline earth element.
- a second baking step in which at least one additional element selected from the group consisting of an element and an alkaline earth element is attached and then further baking is preferably obtained.
- the coprecipitate is generated from a solution in which aluminum, the metal element, and the additive element are dissolved.
- the aluminum content in such a solution is preferably 48 to 95 at% as an element with respect to the total amount of the aluminum, the metal element and the additive element, and is preferably 50 to 93 at%. It is more preferable. If the aluminum content in the solution is less than the lower limit, the heat resistance of the resulting inorganic oxide tends to be insufficient. On the other hand, if the upper limit is exceeded, the steam reforming reaction when rhodium is supported and used as a catalyst. The activity tends to decrease.
- the content ratio of the additive element in such a solution is preferably set to 0.3 to 5.7 at% as an element with respect to the total amount of the additive element, aluminum, and the metal element. 0.3 to 4.6 at% is more preferable.
- the content of the additive element in the solution is If it is less than the lower limit, when the resulting inorganic oxide is used as a carrier, the effect of suppressing the grain growth of the inorganic oxide tends to be insufficient. On the other hand, if the upper limit is exceeded, the resulting inorganic oxide When is used as a support, the catalytic activity tends to decrease because the interaction with the catalytic metal is too strong.
- a solution obtained by dissolving a salt of each metal element constituting an inorganic oxide in water, alcohol or the like is preferably used.
- Such salts include sulfates, nitrates, hydrochlorides, acetates and the like.
- the pH of the solution is adjusted to a range in which the hydroxide of each metal element is precipitated (preferably pH 9 or more). Coprecipitates containing aluminum, etc. can be produced.
- a solution of ammonia or ammonium carbonate is preferably used because it can be easily removed by volatilization during firing.
- the obtained coprecipitate is preferably centrifuged and washed, and then fired by heating to obtain an oxide mixture.
- the coprecipitate is fired by heating in an oxidizing atmosphere such as an air atmosphere at 600 to 1200 ° C, preferably 0.5 to 10 hours.
- an additive element is attached to the oxide mixture, and further fired to obtain a particulate inorganic oxide.
- most of the adhering additive elements are converted into oxides upon firing, and are present in the primary particle surface layer, whereby an inorganic oxide having a surface concentrated region can be obtained.
- the additive element As a method of attaching the additive element in this manner, a method of suspending a mixture of oxides in a solution in which a salt (nitrate or the like) of the additive element is dissolved and stirring the mixture element may be mentioned. Is possible. Further, the amount of the additive element attached to the oxide mixture is as an element with respect to the total amount of the inorganic oxide from the viewpoint of adjusting the amount of the additive element in the surface concentration region of the obtained inorganic oxide. 0.6-3. Oat% is preferable. 1.0-0.2.8 at% is more preferable.
- the firing temperature is preferably in the range of 400 to 1100 ° C, more preferably in the range of 500 to 900 ° C.
- the firing temperature is If it is less than the lower limit, it becomes difficult to make the surface enriched region of the obtained inorganic oxide in an appropriate range, and the interaction between the catalyst metal and the additive element tends not to be properly controlled. On the other hand, when the upper limit is exceeded, the reaction between the additive element and the oxide mixture proceeds, and it tends to be difficult to maintain the surface concentrated region.
- the firing time is preferably in the range of 0.5 to 10 hours.
- the exhaust gas purifying catalyst of the present invention is formed by supporting rhodium on the inorganic oxide of the present invention described above.
- the solid basicity of the carrier is appropriately controlled by using the inorganic oxide of the present invention in which the amount of the additive element in the surface concentration region is appropriately adjusted as the carrier. Has been. And by controlling the solid basicity of the carrier appropriately in this way, it is presumed that the movement of the supported rhodium is suppressed even in a high temperature environment, and the grain growth is suppressed.
- a catalyst component supporting a catalytic metal other than rhodium such as platinum or palladium.
- Rhodium can be supported on a carrier by employing a conventionally known method such as an impregnation method.
- the inorganic oxide of the present invention may further carry a catalyst metal other than rhodium such as platinum and palladium.
- At least a part of rhodium in the exhaust gas purifying catalyst of the present invention is a region where the content ratio of the additive element is locally increased in the surface layer portion of the primary particles of the inorganic oxide (surface enrichment region). It is preferable that it is carried so as to come into contact with. As a result, the effect of suppressing the growth of rhodium grains by the additive element is more remarkably exhibited.
- the amount of rhodium supported is preferably 0.01 to 3 parts by mass with respect to 100 parts by mass of the carrier in order to develop sufficiently high catalytic activity. Can be more Preferred 0.:! To 1 part by mass is more preferred.
- the form in which such an exhaust gas purifying catalyst is used is not particularly limited.
- the exhaust purifying catalytic force is provided on the surface of a substrate such as a honeycomb-shaped monolith substrate, pellet substrate, or foam substrate. It can be used by forming a layer and placing it in an exhaust passage of an internal combustion engine or the like.
- a solution obtained by dissolving 1 mol of aluminum nitrate nonahydrate, 0.95 mol of zirconium oxynitrate dihydrate and 0.05 mol of lanthanum nitrate hexahydrate in 1600 mL of ion-exchanged water was used.
- the pH of the solution is adjusted to 9 or more, and aluminum, zirconium and lanthanum are hydroxylated.
- the product was coprecipitated to obtain a hydroxide precursor. Then, the obtained hydroxide precursor was centrifuged and thoroughly washed, and then calcined by heating at 400 ° C.
- the solid material after the pre-baking is heated in the atmosphere at 700 ° C for 5 hours, and further heated at 900 ° C for 5 hours (first baking) to obtain aluminum oxide (Al 2 O 3).
- Al 2 O 3 aluminum oxide
- ZrO Zirconium oxide
- La O lanthanum oxide
- composition ratio in the resulting mixture is Al 2 O 3 / ZrO
- the content of aluminum oxide was 50 at% as an element with respect to the total amount of lanthanum, aluminum and dinoleconium.
- the element content was 49.5 at% with respect to the total amount of zirconium.
- the content ratio of additive elements (lanthanum and neodymium) in the obtained inorganic oxide was 3.6 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- 80% or more of the primary particles had a particle diameter of 1 OO nm or less.
- An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that the ratio was /95/2.5 (molar ratio).
- the content ratio of aluminum oxide in the obtained inorganic oxide was 59.4 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide was 3. Oat% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium, and 80% of the primary particles. More than% had a particle size of l OOnm or less.
- An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that the ratio was /95/2.5 (molar ratio).
- the content of aluminum oxide in the obtained inorganic oxide was 66. Oat as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium. %Met.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 2.6 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum, and zirconium. More than% had a particle size of lOOnm or less.
- An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that the ratio was /95/2.5 (molar ratio).
- the content ratio of aluminum oxide in the obtained inorganic oxide was 79.4 at Q / o as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content ratio of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 1.8 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium, and 80% of the primary particles. More than% had a particle size of lOOnm or less.
- An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that the molar ratio was 0/95 / 2.5 (molar ratio).
- the content ratio of aluminum oxide in the obtained inorganic oxide was 91.7 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content ratio of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 1. lat% as an element with respect to the total amount of lanthanum, neodymium, aluminum and dinoleconium, and 80% or more of primary particles Had a particle size of lOOnm or less.
- Example 1 48 g of the first calcined mixture obtained in Example 1 was mixed with 5.3 g of neodymium nitrate hexahydrate ( Example 1 except that the suspension was suspended in a neodymium nitrate aqueous solution in which 4 mass% in terms of neodymium oxide was dissolved with respect to the total amount of the inorganic oxide obtained. Similarly, an inorganic oxide and an exhaust gas purification catalyst were obtained. In the obtained inorganic oxide, the content ratio of the anodized aluminum oxide was 48.9 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide was 4.6 at as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium. / 0 and 80 of primary particles. More than / o has a particle size of 1 OOnm or less.
- a solution obtained by dissolving 1 mol of aluminum nitrate nonahydrate, 0.95 mol of zirconium oxynitrate dihydrate and 0.05 mol of neodymium nitrate hexahydrate in 1600 mL of ion-exchanged water was used. While stirring well, in addition to aqueous ammonia containing 1.2 times the neutralization equivalent to the metal cation in the solution, the pH of the solution is adjusted to 9 or more, and aluminum, zirconium and neodymium are hydroxylated. The product was coprecipitated to obtain a hydroxide precursor.
- the obtained hydroxide precursor was centrifuged and sufficiently washed, and then calcined by heating in the atmosphere at 400 ° C. for 5 hours. Subsequently, the pre-baked solid material is heated in the atmosphere at 700 ° C for 5 hours, and further heated at 900 ° C for 5 hours (first baking) to obtain aluminum oxide (Al 2 O 3). ), Zirconium oxide (ZrO) and neodymium oxide (Nd 2 O 3)
- the content of aluminum oxide was 50 at% as an element with respect to the total amount of neodymium, aluminum and zirconium.
- the element content was 48.9 at% based on the total amount of zirconium.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide was 4.6 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium. Further, when the obtained inorganic oxide was observed by TEM, 80% or more of the primary particles had a particle diameter of 10 Onm or less.
- An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 5 except that the second baking temperature was 500 ° C.
- the content ratio of aluminum oxide in the obtained inorganic oxide was 91.7 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content ratio of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 1. lat% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium, and 80% or more of primary particles Had a particle size of lOOnm or less.
- Example 7 An inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 7, except that a suspension suspended in an aqueous solution of dissolved lanthanum nitrate was used and the second calcination temperature was set to 1000 ° C.
- the content ratio of aluminum oxide in the obtained inorganic oxide was 48.3 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum, and dinoleconium.
- the content of additive elements (lanthanum and neodymium) in the oxide is 5.9 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium, and 80% or more of primary particles are less than lOOnm. It had a particle size.
- a comparative inorganic oxide and exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that the ratio was /95/2.5 (molar ratio).
- the content ratio of aluminum oxide in the obtained inorganic oxide was 32.9 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content ratio of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 4.5 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum, and zirconium. More than% had a particle size of lOOnm or less.
- a comparative inorganic oxide and exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that 49 g of aluminum oxide was used instead of 49 g of the first fired mixture obtained in Example 1.
- the content ratio of aluminum oxide in the obtained inorganic oxide was 99.4 at% as an element with respect to the total amount of lanthanum, neodymium and aluminum.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 0.6 at% as an element with respect to the total amount of lanthanum, neodymium and aluminum, and 80% or more of primary particles It had a particle size of lOOnm or less.
- Neodymium nitrate hexahydrate used in Example 6 5.3 g of lanthanum nitrate hexahydrate instead of 3 g (amount of 5% by mass in terms of lanthanum oxide based on the total amount of the obtained inorganic oxide)
- a comparative inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 6 except that the second firing temperature was changed to 500 ° C.
- the content of aluminum oxide in the resulting inorganic oxide is 48% as an element with respect to the total amount of lanthanum, aluminum and dinoleconium. It was 7at%.
- the content of the additive element (lanthanum) in the obtained inorganic oxide is 5. lat% as an element with respect to the total amount of lanthanum, aluminum and zirconium, and 80% or more of the primary particles are particles of lOOnm or less. Had a diameter.
- a comparative inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 1 except that 49 g of the first-calcined mixture obtained in Example 1 was not impregnated with an aqueous neodymium nitrate solution.
- the content of aluminum oxide in the obtained inorganic oxide was 50. Oat% as an element with respect to the total amount of lanthanum, aluminum and dinoleconium.
- the content of the additive element (lanthanum) in the obtained inorganic oxide is 2.5at as an element with respect to the total amount of lanthanum, aluminum and zirconium.
- a comparative inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 6 except that the amount was 2) and the second firing temperature was 500 ° C.
- the content ratio of aluminum oxide in the obtained inorganic oxide was 48.7 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content of additive elements (lanthanum and neodymium) in the obtained inorganic oxide is 5. lat% as an element with respect to the total amount of lanthanum, aluminum and zirconium, and 80% or more of primary particles are less than lOOnm. It had a particle size of.
- Neodymium nitrate hexahydrate used in Example 6 5.3 g of lanthanum nitrate hexahydrate instead of 3 g (amount of 5% by mass in terms of lanthanum oxide based on the total amount of the obtained inorganic oxide)
- a comparative inorganic oxide and an exhaust gas purification catalyst were obtained in the same manner as in Example 6 except that the above was used.
- the content ratio of aluminum oxide in the obtained inorganic oxide was 48.7 at% as an element with respect to the total amount of lanthanum, aluminum and dinoleconium.
- the content of the additive element (lanthanum) in the obtained inorganic oxide is lanthanum, aluminum and di
- the total amount of ruconium was 5. lat% as an element, and 80% or more of the primary particles had a particle size of 1 OOnm or less.
- a comparative inorganic oxide and exhaust gas purification catalyst were obtained in the same manner as in Example 6 except that the amount was used.
- the content of aluminum oxide in the obtained inorganic oxide was 48.7 at% as an element with respect to the total amount of lanthanum, neodymium, aluminum and zirconium.
- the content of additive elements (lanthanum and neodymium) in the resulting inorganic oxide is 5. lat% as an element with respect to the total amount of lanthanum, aluminum and zirconium, and 80% or more of primary particles are less than lOOnm.
- the particle diameter was as follows.
- the rhodium reduction characteristics of the exhaust gas-purifying catalyst after the durability test were evaluated.
- the temperature desorption measurement device (manufactured by Okura Riken) was used as the measurement device, and the hydrogen consumption in the exhaust gas purification catalyst after the endurance test was measured under the following measurement conditions.
- the hydrogen consumption is an index reflecting both the ease of reduction of rhodium oxide to metal and the number of effective active sites of rhodium. The larger the measured value, the higher the catalytic activity. And it can be evaluated that the larger the measured value of hydrogen consumption, the better the heat resistance of the catalyst.
- Table 1 shows the amount of additive elements in the surface enriched region of the inorganic oxides obtained in Examples 1 to 9 and Comparative Examples 1 to 7, and the hydrogen consumption in the exhaust gas purifying catalyst.
- Table 1 shows the content ratio of aluminum oxide and the element type and content ratio of the additive element in the mixture and inorganic oxide after the first firing obtained in Examples 1 to 9 and Comparative Examples 1 to 7. Shown in
- Example 19 is a hydrogen consumption after endurance test. A large amount of catalyst activity was excellent. Therefore, it was confirmed that the exhaust gas purifying catalyst using the inorganic oxide of the present invention has excellent heat resistance.
- an inorganic oxide having excellent heat resistance and an exhaust gas purification catalyst using the inorganic oxide it is possible to provide an inorganic oxide having excellent heat resistance and an exhaust gas purification catalyst using the inorganic oxide.
Abstract
Description
Claims
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US12/300,676 US20090149321A1 (en) | 2006-06-16 | 2007-06-08 | Inorganic oxide and catalyst for purification of exhaust gas obtained by using the same |
EP07767080A EP2036606A4 (en) | 2006-06-16 | 2007-06-08 | INORGANIC OXIDE AND CATALYST FOR EXHAUST GAS PURIFICATION PRODUCED USING THE SAME |
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JP2006167111A JP4726714B2 (ja) | 2006-06-16 | 2006-06-16 | 無機酸化物、及びそれを用いた排ガス浄化用触媒 |
JP2006-167111 | 2006-06-16 |
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EP (1) | EP2036606A4 (ja) |
JP (1) | JP4726714B2 (ja) |
KR (1) | KR20090025339A (ja) |
CN (1) | CN101479036A (ja) |
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JP2007301526A (ja) * | 2006-05-15 | 2007-11-22 | Toyota Central Res & Dev Lab Inc | 排ガス浄化用触媒及びその製造方法 |
JP5099828B2 (ja) * | 2007-10-31 | 2012-12-19 | 株式会社豊田中央研究所 | 無機混合酸化物及びそれを用いた排ガス浄化用触媒 |
JP5903205B2 (ja) * | 2010-01-04 | 2016-04-13 | 株式会社キャタラー | 排ガス浄化用触媒 |
US9592498B2 (en) | 2010-11-16 | 2017-03-14 | Rhodia Operations | Porous inorganic composite oxide |
JP5900395B2 (ja) * | 2012-11-22 | 2016-04-06 | トヨタ自動車株式会社 | 複合酸化物粒子及びこれを用いた排ガス浄化用触媒 |
JP5883425B2 (ja) * | 2013-10-04 | 2016-03-15 | 株式会社豊田中央研究所 | セリア−ジルコニア系複合酸化物及びその製造方法、並びにそのセリア−ジルコニア系複合酸化物を用いた排ガス浄化用触媒 |
JP6247922B2 (ja) * | 2013-12-12 | 2017-12-13 | 株式会社キャタラー | 排ガス浄化用触媒 |
RU2698675C2 (ru) * | 2013-12-23 | 2019-08-28 | Родиа Операсьон | Неорганический оксидный материал |
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US8242046B2 (en) * | 2004-07-22 | 2012-08-14 | Toyota Jidosha Kabushiki Kaisha | Inorganic oxide, exhaust gas purifying catalyst carrier, and exhaust gas purifying catalyst |
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2006
- 2006-06-16 JP JP2006167111A patent/JP4726714B2/ja active Active
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2007
- 2007-06-08 KR KR1020097000809A patent/KR20090025339A/ko not_active Application Discontinuation
- 2007-06-08 EP EP07767080A patent/EP2036606A4/en not_active Withdrawn
- 2007-06-08 CN CNA2007800223991A patent/CN101479036A/zh active Pending
- 2007-06-08 US US12/300,676 patent/US20090149321A1/en not_active Abandoned
- 2007-06-08 WO PCT/JP2007/061659 patent/WO2007145145A1/ja active Application Filing
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EP2036606A1 (en) | 2009-03-18 |
US20090149321A1 (en) | 2009-06-11 |
CN101479036A (zh) | 2009-07-08 |
EP2036606A4 (en) | 2010-01-13 |
JP2007331992A (ja) | 2007-12-27 |
JP4726714B2 (ja) | 2011-07-20 |
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