JPH10286462A - Catalyst of purifying exhaust gas - Google Patents
Catalyst of purifying exhaust gasInfo
- Publication number
- JPH10286462A JPH10286462A JP9093763A JP9376397A JPH10286462A JP H10286462 A JPH10286462 A JP H10286462A JP 9093763 A JP9093763 A JP 9093763A JP 9376397 A JP9376397 A JP 9376397A JP H10286462 A JPH10286462 A JP H10286462A
- Authority
- JP
- Japan
- Prior art keywords
- mol
- exhaust gas
- catalyst
- zirconium oxide
- gas purifying
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 175
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims abstract description 105
- 229910001928 zirconium oxide Inorganic materials 0.000 claims abstract description 105
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 67
- 239000010948 rhodium Substances 0.000 claims abstract description 46
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 43
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 43
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 31
- 229910052779 Neodymium Inorganic materials 0.000 claims abstract description 20
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 20
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims abstract description 17
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229910052751 metal Inorganic materials 0.000 claims abstract description 13
- 239000002184 metal Substances 0.000 claims abstract description 13
- 229910052777 Praseodymium Inorganic materials 0.000 claims abstract description 6
- 125000004430 oxygen atom Chemical group O* 0.000 claims abstract description 6
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052727 yttrium Inorganic materials 0.000 claims abstract description 6
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000007789 gas Substances 0.000 claims description 110
- 238000000746 purification Methods 0.000 claims description 37
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 35
- 239000010410 layer Substances 0.000 claims description 33
- 229910052726 zirconium Inorganic materials 0.000 claims description 25
- 229910052684 Cerium Inorganic materials 0.000 claims description 22
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 20
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 20
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 17
- 229910052783 alkali metal Inorganic materials 0.000 claims description 11
- 150000001340 alkali metals Chemical class 0.000 claims description 11
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 11
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 10
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 10
- 239000002344 surface layer Substances 0.000 claims description 4
- 230000000694 effects Effects 0.000 abstract description 41
- 239000000843 powder Substances 0.000 description 104
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 60
- 239000011575 calcium Substances 0.000 description 34
- 229910052763 palladium Inorganic materials 0.000 description 28
- 230000003197 catalytic effect Effects 0.000 description 17
- 238000000034 method Methods 0.000 description 16
- 239000002002 slurry Substances 0.000 description 15
- 229910000510 noble metal Inorganic materials 0.000 description 13
- 229910052760 oxygen Inorganic materials 0.000 description 11
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 10
- 239000007864 aqueous solution Substances 0.000 description 10
- 229920006395 saturated elastomer Polymers 0.000 description 10
- 229910052791 calcium Inorganic materials 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 9
- 239000001301 oxygen Substances 0.000 description 9
- 231100000572 poisoning Toxicity 0.000 description 9
- 230000000607 poisoning effect Effects 0.000 description 9
- 239000000243 solution Substances 0.000 description 9
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 150000001875 compounds Chemical class 0.000 description 8
- 230000007423 decrease Effects 0.000 description 8
- 239000000203 mixture Substances 0.000 description 7
- 238000005245 sintering Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 239000013078 crystal Substances 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 238000001556 precipitation Methods 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 150000003839 salts Chemical class 0.000 description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 4
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 4
- 229910052792 caesium Inorganic materials 0.000 description 4
- -1 cesium compound Chemical class 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 239000000446 fuel Substances 0.000 description 4
- 238000005470 impregnation Methods 0.000 description 4
- 229910017604 nitric acid Inorganic materials 0.000 description 4
- 229910052700 potassium Inorganic materials 0.000 description 4
- 239000011591 potassium Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 3
- 150000003868 ammonium compounds Chemical class 0.000 description 3
- 235000011114 ammonium hydroxide Nutrition 0.000 description 3
- 229910052788 barium Inorganic materials 0.000 description 3
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 3
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000002779 inactivation Effects 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 229910052712 strontium Inorganic materials 0.000 description 3
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 3
- 230000002195 synergetic effect Effects 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 2
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 150000001341 alkaline earth metal compounds Chemical class 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000006073 displacement 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
- 238000010304 firing Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 239000011777 magnesium Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 150000002823 nitrates Chemical class 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 239000012495 reaction gas Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 1
- 101100008049 Caenorhabditis elegans cut-5 gene Proteins 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- 241000968352 Scandia <hydrozoan> Species 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 150000001553 barium compounds Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- 235000012255 calcium oxide Nutrition 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- HJGMWXTVGKLUAQ-UHFFFAOYSA-N oxygen(2-);scandium(3+) Chemical compound [O-2].[O-2].[O-2].[Sc+3].[Sc+3] HJGMWXTVGKLUAQ-UHFFFAOYSA-N 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 150000003112 potassium compounds Chemical class 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- VXNYVYJABGOSBX-UHFFFAOYSA-N rhodium(3+);trinitrate Chemical compound [Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VXNYVYJABGOSBX-UHFFFAOYSA-N 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000012619 stoichiometric conversion Methods 0.000 description 1
- 150000003438 strontium compounds Chemical class 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
- 150000003755 zirconium compounds Chemical class 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、排気ガス浄化用触
媒に関し、特に自動車等の内燃機関から排出される排気
ガス中の炭化水素（以下、「ＨＣ」と称す）、一酸化炭
素（以下、「ＣＯ」と称す）及び窒素酸化物（以下、
「ＮＯｘ」と称す）を効率良く浄化することができ、し
かも、高温耐久性に優れるとともに耐久後も低温活性と
浄化性能に優れる排気ガス浄化用触媒に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying catalyst and, more particularly, to hydrocarbons (hereinafter referred to as "HC") and carbon monoxide (hereinafter referred to as "HC") in exhaust gas discharged from an internal combustion engine of an automobile or the like. "CO") and nitrogen oxides (hereinafter, referred to as "CO").
The present invention relates to an exhaust gas purifying catalyst that can efficiently purify NOx), has excellent high-temperature durability, and has excellent low-temperature activity and purification performance even after durability.
【０００２】[0002]
【従来の技術】従来より、排気ガス浄化用触媒は高温下
での耐久性が十分でなく、耐久後は触媒が劣化し排気ガ
スに対する浄化能が著しく低下するため、高温耐久後も
低温活性と浄化性能に優れる排気ガス浄化用触媒の開発
が期待されている。2. Description of the Related Art Conventionally, exhaust gas purifying catalysts have not been sufficiently durable at high temperatures, and after the durability, the catalyst deteriorates and the purification performance for exhaust gas is remarkably reduced. The development of an exhaust gas purification catalyst having excellent purification performance is expected.
【０００３】かかる排気ガス浄化用触媒としては、例え
ば、特公昭５８−２０３０７号公報、特開昭６２−２８
２６４１号公報、特開平４−２８４８４７号公報、特開
平６−３７８号公報及び特開平７−６０１１８号公報に
開示されているものがある。特公昭５８−２０３０７号
公報に記載された排気ガス浄化用触媒は、白金、ロジウ
ム及びセリウムから成る組成物を耐火性担体に担持させ
たものであり、具体的にはアルミナや酸化セリウムなど
に白金、パラジウム及びロジウムなどの白金族元素を担
持させ、これをモノリス担体にコーティングした構造の
ものである。As such exhaust gas purifying catalysts, for example, JP-B-58-20307 and JP-A-62-28
2641, JP-A-4-284847, JP-A-6-378 and JP-A-7-60118. The exhaust gas purifying catalyst described in Japanese Patent Publication No. 58-20307 is a catalyst in which a composition comprising platinum, rhodium and cerium is supported on a refractory carrier, and specifically, platinum on alumina or cerium oxide. , Palladium, rhodium, and other platinum group elements, and a monolithic carrier coated with the element.
【０００４】また特開昭６２−２８２６４１号公報に
は、ロジウムを酸化ジルコニウムに担持させた排気ガス
浄化用触媒が開示されており、具体的にはロジウムを含
有させた酸化ジルコニウム、活性アルミナ、酸化セリウ
ムとアルミナゾルとを含むスラリーを、担体に付着・乾
燥・焼成した後、白金を担持させた排気ガス浄化用触媒
が開示されている。Japanese Patent Application Laid-Open No. 62-282641 discloses a catalyst for purifying exhaust gas in which rhodium is supported on zirconium oxide. More specifically, zirconium oxide containing rhodium, activated alumina, oxidized alumina, and the like are disclosed. An exhaust gas purifying catalyst is disclosed in which a slurry containing cerium and alumina sol is adhered to a carrier, dried, and calcined, and then platinum is supported.
【０００５】特開平４−２８４８４７号公報には、白
金、ロジウム、活性アルミナ、酸化セリウム等の従来か
ら触媒成分として使用されているものに加え、酸化セリ
ウムとランタン、プラセオジウム、イットリウム、ネオ
ジウム、２Ａ族及び３Ｂ族から選ばれた一種又は一種以
上の金属酸化物により安定化されたジルコニウム化合物
とを組み合わせた排気ガス浄化用触媒が開示されてい
る。Japanese Patent Application Laid-Open No. 4-284847 discloses that in addition to those conventionally used as catalyst components such as platinum, rhodium, activated alumina and cerium oxide, cerium oxide and lanthanum, praseodymium, yttrium, neodymium and 2A group And an exhaust gas purifying catalyst in which a zirconium compound stabilized by one or more metal oxides selected from Group 3B is disclosed.
【０００６】特開平６−３７８号公報には、活性アルミ
ナと酸化セリウムに、触媒成分として白金及び／又はパ
ラジウムと、塩基性元素であるカリウム、セシウム、ス
トロンチウム及びバリウムから成る群より選ばれた少な
くとも一種の金属の酸化物とが担持された排気ガス浄化
用触媒が提案されている。換言すれば、当該触媒は、白
金族元素、活性アルミナ、酸化セリウム等の従来から触
媒成分として使用されているものに加え、塩基性元素で
ある、カリウム化合物、セシウム化合物、ストロンチウ
ム化合物及びバリウム化合物のうち少なくとも一種類と
組み合わせてなるものである。[0006] JP-A-6-378 discloses that activated alumina and cerium oxide contain at least one selected from the group consisting of platinum and / or palladium as a catalyst component and potassium, cesium, strontium and barium as basic elements. Exhaust gas purifying catalysts supporting a kind of metal oxide have been proposed. In other words, the catalyst is a platinum group element, activated alumina, in addition to those conventionally used as a catalyst component such as cerium oxide, and a basic element such as a potassium compound, a cesium compound, a strontium compound and a barium compound. It is a combination of at least one of them.
【０００７】特開平７−６０１１８号公報には、イット
リア、カルシア、マグネシア又はスカンジアで安定化さ
れたジルコニウム酸化物と４０〜９５重量％のアルミナ
又はチタニアからなり、３０〜３００ｍ2 ｇの表面積を
有する酸素イオン伝導性複合体を、ロジウム／白金、ロ
ジウム／パラジウムの担持基材として用いる貴金属触媒
が提案されている。Japanese Patent Application Laid-Open No. 7-60118 discloses that a zirconium oxide stabilized with yttria, calcia, magnesia or scandia and 40 to 95% by weight of alumina or titania have a surface area of 30 to 300 m 2 g. Noble metal catalysts using an oxygen ion conductive composite as a supporting substrate for rhodium / platinum and rhodium / palladium have been proposed.
【０００８】[0008]
【発明が解決しようとする課題】しかし、前記公報中に
記載された従来の触媒は、初期状態から高温耐久後まで
高い排気ガス浄化性能を維持するため、高価な貴金属を
多量に使用しなければならず、このため、排気ガスの浄
化を目的とする三元触媒として、使用する貴金属量が少
なくても高い浄化性能が得られる触媒が望まれている。
然るに、従来の触媒中の貴金属量を低減した場合には、
高温下における耐久性が不十分となり、また耐久後は低
温域での触媒活性や排気ガス浄化性能が悪化するという
問題点があった。However, the conventional catalyst described in the above-mentioned publication maintains high exhaust gas purification performance from an initial state to after high-temperature durability, so that a large amount of expensive noble metal must be used. For this reason, there is a demand for a three-way catalyst for purifying exhaust gas that can achieve high purification performance even when the amount of noble metal used is small.
However, when the amount of noble metal in the conventional catalyst is reduced,
There has been a problem that the durability at high temperatures becomes insufficient, and after the durability, the catalytic activity and the exhaust gas purification performance at low temperatures deteriorate.
【０００９】これは、理論空燃比（以下、「ストイキ」
と称す）を中心に、酸素濃度が不十分な還元雰囲気（以
下、「リッチ」と称す）から酸素濃度が過剰な酸化雰囲
気（以下、「リーン」と称す）まで幅広く組成が変化す
る自動車の排気ガス雰囲気下では、貴金属種の劣化（シ
ンタリング）が促進され、その結果浄化性能が低下する
ためと考えられる。特に、貴金属量を低減する場合に
は、上記影響が顕著に現れて、さらに浄化性能が低下す
るという問題があった。This is based on the stoichiometric air-fuel ratio (hereinafter referred to as "stoichiometric").
The exhaust of automobiles whose composition varies widely from a reducing atmosphere with insufficient oxygen concentration (hereinafter referred to as "rich") to an oxidizing atmosphere with excessive oxygen concentration (hereinafter referred to as "lean"). It is considered that the deterioration (sintering) of the noble metal species is promoted in the gas atmosphere, and as a result, the purification performance is reduced. In particular, when the amount of the noble metal is reduced, there is a problem that the above-described effect is remarkably exhibited and the purification performance is further reduced.
【００１０】また、通常アルミナは熱安定性が不十分
で、高温下ではその結晶構造が変化し、ＢＥＴ比表面積
が著しく小さなα−アルミナへ相転移を起こす。この際
に、貴金属のシリングを促進したり、また、アルミナが
貴金属と固相反応を起こして不活性な化合物を形成し、
その結果浄化性能が大きく低下する。一方、酸化ジルコ
ニウムは熱に対する構造安定性に優れるが、ＢＥＴ比表
面積が小さいため貴金属の分散性が悪く、初期状態から
高温耐久後まで充分な低温活性や浄化性能を得ることが
難しいという問題もあった。Alumina usually has insufficient thermal stability, and its crystal structure changes at high temperatures, causing a phase transition to α-alumina having a very small BET specific surface area. At this time, it promotes the shilling of the noble metal, and the alumina causes a solid-phase reaction with the noble metal to form an inert compound,
As a result, purification performance is greatly reduced. On the other hand, zirconium oxide is excellent in structural stability against heat, but has a problem that it has a low BET specific surface area and thus has poor dispersibility of noble metals, and it is difficult to obtain sufficient low-temperature activity and purification performance from the initial state to after high-temperature durability. Was.
【００１１】従って、本発明の目的は、従来の触媒より
も高温耐久性が向上し、耐久後においても優れた低温活
性と浄化性能を有する排気ガス浄化用触媒を提供するこ
とにある。Accordingly, it is an object of the present invention to provide an exhaust gas purifying catalyst having improved high-temperature durability over conventional catalysts and having excellent low-temperature activity and purification performance even after durability.
【００１２】[0012]
【課題を解決するための手段】本発明者らは、上記課題
を解決するために研究した結果、白金及びロジウムの高
温耐久性と触媒活性を向上させるために、触媒成分担持
中に白金やロジウムと共に、ジルコニウム酸化物を含有
させることにより、高温耐久性を改善し、耐久後の低温
活性や浄化性能が著しく向上して維持されることを見出
し、本発明に到達した。Means for Solving the Problems The inventors of the present invention have studied to solve the above-mentioned problems, and as a result, in order to improve the high-temperature durability and catalytic activity of platinum and rhodium, platinum and rhodium were added during loading of the catalyst component. At the same time, it has been found that by containing a zirconium oxide, the high-temperature durability is improved, and the low-temperature activity and purification performance after the durability are remarkably improved and maintained.
【００１３】請求項１記載の排気ガス浄化用触媒は、触
媒成分担持層を有する一体構造型触媒において、少なく
ともロジウム担持ジルコニウム酸化物と白金担持ジルコ
ニウム酸化物とを含有することを特徴とする。According to a first aspect of the present invention, there is provided an exhaust gas purifying catalyst, wherein the catalyst has a catalyst component-supporting layer and comprises at least rhodium-supported zirconium oxide and platinum-supported zirconium oxide.
【００１４】更に、請求項１記載の排気ガス浄化用触媒
の耐久性と触媒能を更に向上させるために、請求項２記
載の排気ガス浄化用触媒は、上記のロジウムを担持する
ジルコニウム酸化物が、次の一般式； Ｎｄa Ｃａb Ｚｒc Ｏd （式中、ａ，ｂ及びｃは、各元素の原子比率を示し、金
属換算で、ａ＝０．０１〜２０モル％、ｂ＝０．０５〜
２０モル％、ｃ＝６０〜９５モル％、ｄは上記各成分の
原子価を満足するのに必要な酸素原子数である）で表さ
れることを特徴とする。Further, in order to further improve the durability and catalytic performance of the exhaust gas purifying catalyst according to the first aspect, the exhaust gas purifying catalyst according to the second aspect is characterized in that the zirconium oxide carrying rhodium contains the zirconium oxide. the following general formula; Nd a Ca b Zr c O d ( where, a, b and c represents an atomic ratio of each element, in terms of a metal, a = 0.01 to 20 mol%, b = 0 .05-
20 mol%, c = 60 to 95 mol%, and d is the number of oxygen atoms necessary to satisfy the valence of each component).
【００１５】更に、請求１又は２記載の排気ガス浄化用
触媒の耐被毒性とリッチ雰囲気下における触媒活性を更
に向上させるために、請求項３記載の排気ガス浄化用触
媒は、上記の白金を担持するジルコニウム酸化物が、次
の一般式； 〔Ｘ〕 eＣｅf Ｚｒg Ｏh （式中、Ｘは、プラセオジウム、イットリウム、ランタ
ン及びネオジウムからなる群より選ばれた少なくとも一
種の元素であり、ｅ，ｆ及びｇは、各元素の原子比率を
示し、金属換算で、ｅ＝０．０１〜１０モル％、ｆ＝５
〜３０モル％、ｇ＝６５〜９５モル％、ｈは上記各成分
の原子価を満足するのに必要な酸素原子数である）で表
されることを特徴とする。Further, in order to further improve the poisoning resistance of the exhaust gas purifying catalyst according to the first or second aspect and the catalytic activity in a rich atmosphere, the exhaust gas purifying catalyst according to the third aspect uses the platinum as a catalyst. zirconium oxide carrying the following general formula; [X] in e Ce f Zr g O h (wherein, X is praseodymium, yttrium, at least one element selected from the group consisting of lanthanum and neodymium, e, f, and g indicate the atomic ratio of each element, e = 0.01 to 10 mol%, and f = 5 in terms of metal.
３０30 mol%, g = 65-95 mol%, and h is the number of oxygen atoms necessary to satisfy the valence of each of the above components.
【００１６】更に、請求項１〜３いずれかの項記載の排
気ガス浄化用触媒のコーティング性を改良し、しかも、
耐久性を更に高めるために、請求項４記載の排気ガス浄
化用触媒は、上記触媒成分担持層中に更にパラジウム担
持アルミナを含有し、該アルミナはセリウム、ジルコニ
ウム及びランタンからなる群より選ばれた少なくとも一
種を金属換算で１〜１０％含むことを特徴とする。Further, the coating property of the exhaust gas purifying catalyst according to any one of claims 1 to 3 is improved, and
In order to further enhance the durability, the exhaust gas purifying catalyst according to claim 4 further contains palladium-supported alumina in the catalyst component-supporting layer, wherein the alumina is selected from the group consisting of cerium, zirconium, and lanthanum. It is characterized in that at least one kind is contained in an amount of 1 to 10% in terms of metal.
【００１７】請求項１〜４いずれかの項記載の排気ガス
浄化用触媒の低温活性とＨＣ浄化性能を更に向上させる
ために、請求項５記載の排気ガス浄化用触媒は、上記触
媒成分担持層中に、更にパラジウム担持セリウム酸化物
を含有し、該セリウム酸化物は、ジルコニウム、ネオジ
ウム及びランタンからなる群より選ばれた一種を金属換
算で１〜４０モル％含むことを特徴とする。In order to further improve the low-temperature activity and the HC purification performance of the exhaust gas purifying catalyst according to any one of the first to fourth aspects, the exhaust gas purifying catalyst according to the fifth aspect includes the catalyst component supporting layer. The cerium oxide further contains a palladium-supported cerium oxide, and the cerium oxide contains 1 to 40 mol% of a metal selected from the group consisting of zirconium, neodymium and lanthanum in terms of metal.
【００１８】更に、請求項４又は５記載の排気ガス浄化
用触媒におけるパラジウムとロジウムとの耐被毒性向上
という相乗効果をよく発現させるために、請求項６記載
の排気ガス浄化用触媒は、請求項４又は５記載の排気ガ
ス浄化用触媒において、ロジウム担持ジルコニウム酸化
物を表層側に、パラジウム担持触媒成分を内層側に配置
して成ることを特徴とする。Furthermore, in order to achieve a good synergistic effect of improving the poisoning resistance of palladium and rhodium in the exhaust gas purifying catalyst according to claim 4 or 5, the exhaust gas purifying catalyst according to claim 6 is preferable. Item 4. The exhaust gas purifying catalyst according to item 4 or 5, wherein a rhodium-supported zirconium oxide is disposed on a surface layer and a palladium-supported catalyst component is disposed on an inner layer side.
【００１９】更に、請求項１〜６いずれかの項記載の排
気ガス浄化用触媒の高温耐久後の低温活性とＮＯx 浄化
性能を更に向上させるために、請求項７記載の排気ガス
浄化用触媒は、、更に、アルカリ金属及びアルカリ土類
金属からなる群より選ばれた少なくとも一種が含有する
ことを特徴とする。Furthermore, in order to further improve the low temperature activity and the NO x purification performance after high-temperature durability of the exhaust gas purifying catalyst of claims 1 to 6, wherein any one of claims, the catalyst for purifying exhaust gases according to claim 7, wherein Further contains at least one selected from the group consisting of alkali metals and alkaline earth metals.
【００２０】[0020]
【発明の実施の形態】本発明の排気ガス浄化用触媒の触
媒成分担持層に含有される貴金属としては、少なくとも
ロジウムと白金がある。当該ロジウムの含有量は、触媒
１Ｌ容量中０．０１〜３ｇである。０．０１ｇ未満では
低温活性や浄化性能が十分に発現せず、逆に３ｇを越え
てもロジウムの触媒活性は飽和し、経済的ではない。当
該白金の含有量は、触媒１Ｌ容量中０．０１〜５ｇであ
る。０．０１ｇ未満では低温活性や浄化性能が十分に発
現せず、逆に５ｇを越えても白金の触媒活性は飽和し、
経済的にも有効ではない。このように、ロジウムと白金
を共存させることにより、鉛やイオウ等の被毒物質に対
する耐被毒性を向上させることができる。BEST MODE FOR CARRYING OUT THE INVENTION The noble metals contained in the catalyst component-supporting layer of the exhaust gas purifying catalyst of the present invention include at least rhodium and platinum. The content of the rhodium is 0.01 to 3 g in 1 L of the catalyst. If it is less than 0.01 g, the low-temperature activity and purification performance are not sufficiently exhibited, and if it exceeds 3 g, the catalytic activity of rhodium is saturated, and it is not economical. The content of the platinum is 0.01 to 5 g in 1 L of the catalyst. If the amount is less than 0.01 g, the low-temperature activity and purification performance are not sufficiently exhibited. Conversely, if the amount exceeds 5 g, the catalytic activity of platinum is saturated,
It is not economically effective. Thus, by coexisting rhodium and platinum, the poisoning resistance to poisoning substances such as lead and sulfur can be improved.
【００２１】前記ロジウムが担持される基材としては、
ロジウムの分散性を高め、高温耐久性を向上させるため
に、ジルコニウム酸化物が、また白金が担持される基材
としても、白金の耐久性を向上させるためにジルコニウ
ム酸化物が適切である。As the substrate on which the rhodium is supported,
Zirconium oxide is suitable for enhancing the dispersibility of rhodium and improving high-temperature durability, and zirconium oxide is also suitable for the platinum-supported substrate for improving the durability of platinum.
【００２２】すなわち、ロジウムをジルコニウム酸化物
に担持することによって、耐久後のロジウムの不活性化
を抑制でき、また、白金をジルコニウム酸化物に担持す
ることによって、耐久後の白金の触媒能の低下を抑制で
きる。That is, by supporting rhodium on zirconium oxide, inactivation of rhodium after durability can be suppressed, and by supporting platinum on zirconium oxide, the catalytic performance of platinum after durability can be reduced. Can be suppressed.
【００２３】また、請求項２記載の排気ガス浄化用触媒
は、請求項１記載の排気ガス浄化用触媒の耐久後の浄化
性能を特に高めるために、上記ロジウムを担持するジル
コニウム酸化物が、ネオジウムとカルシウムとを含有す
るもので、かかるジルコニウム酸化物の組成は、Ｎｄa
Ｃａb Ｚｒc Ｏd で表され、前記式中、ａ＝０．０１〜
２０モル％、ｂ＝０．０５〜２０モル％、ｃ＝６０〜９
５モル％である。Further, in the exhaust gas purifying catalyst according to the second aspect, the zirconium oxide carrying rhodium is preferably neodymium in order to particularly enhance the purification performance after the durability of the exhaust gas purifying catalyst according to the first aspect. And calcium, and the composition of such zirconium oxide is Nd a
Represented by Ca b Zr c O d, in the above formula, a = 0.01 to
20 mol%, b = 0.05-20 mol%, c = 60-9
5 mol%.
【００２４】ａ＝０．０１モル％未満では、ジルコニウ
ム酸化物に添加されているネオジウムの結晶構造安定化
という作用が小さく、充分なＢＥＴ表面積改良効果が得
られず、ジルコニア（Ｚｒ０2 ）のみの場合と変わらな
い。また、ａ＝２０モル％を越えると、ネオジウムがジ
ルコニウム酸化物に固溶した上記式で表されるジルコニ
ウム複合酸化物を形成し難くなり、ＢＥＴ比表面積等の
ジルコニア酸化物の物性が低下するためロジウムの分散
性が悪く、初期状態において充分な浄化性能が得られな
い。When a is less than 0.01 mol%, the effect of stabilizing the crystal structure of neodymium added to the zirconium oxide is small, and a sufficient effect of improving the BET surface area cannot be obtained, and only zirconia (ZrO 2 ) is used. It is not different from the case. On the other hand, when a exceeds 20 mol%, it becomes difficult to form a zirconium composite oxide represented by the above formula in which neodymium forms a solid solution in zirconium oxide, and physical properties of the zirconia oxide such as BET specific surface area decrease. The dispersibility of rhodium is poor, and sufficient purification performance cannot be obtained in the initial state.
【００２５】ｂ＝０．０５モル％未満では、ジルコニウ
ム酸化物に添加されているカルシウムのロジウムへの電
子供与という作用が小さく、充分な浄化性能改良効果が
得られず、ジルコニア（Ｚｒ０2 ）のみの場合と変わら
ない。また、ｂ＝２０モル％を越えると、カルシウムが
ジルコニウム酸化物に固溶した上記式で表されるジルコ
ニウム複合酸化物を形成し難くなり、熱安定性等のジル
コニア酸化物の物性が低下するため、高温耐久中にロジ
ウムのシンタリングが促進され、耐久後の浄化性能が悪
化する。If b = less than 0.05 mol%, the effect of calcium added to the zirconium oxide on electron donation to rhodium is small, and a sufficient effect of improving purification performance cannot be obtained, and only zirconia (ZrO 2 ) is obtained. It is not different from the case. On the other hand, if b exceeds 20 mol%, it becomes difficult to form a zirconium composite oxide represented by the above formula in which calcium is dissolved in the zirconium oxide, and physical properties of the zirconia oxide such as thermal stability deteriorate. In addition, sintering of rhodium is promoted during high-temperature durability, and purification performance after durability deteriorates.
【００２６】ｃ＝６０モル％未満では、ネオジウムやカ
ルシウムが固溶した上記式で表されるジルコニウム複合
酸化物を形成し難くなり、熱安定性やＢＥＴ比表面積等
のジルコニウム酸化物の物性が低下するため、初期状態
から充分な浄化性能が得られなかったり、高温耐久後の
該ジルコニウム酸化物の構造安定性が悪化する。また、
ｃ＝９５モル％を越えると、ネオジウムやカルシウムの
構造安定化や電子供与という作用が小さく、充分な浄化
性能改良効果が得られずジルコニア（Ｚｒ０2）のみの
場合と変わらない。When c is less than 60 mol%, it is difficult to form a zirconium composite oxide represented by the above formula in which neodymium or calcium is dissolved, and physical properties of the zirconium oxide such as thermal stability and BET specific surface area are reduced. Therefore, sufficient purification performance cannot be obtained from the initial state, or the structural stability of the zirconium oxide after high-temperature durability deteriorates. Also,
When c exceeds 95 mol%, the effects of neodymium and calcium on stabilizing the structure and electron donating are small, and a sufficient purification performance improving effect cannot be obtained, which is the same as the case of using only zirconia (ZrO 2 ).
【００２７】かかるジルコニウム酸化物の使用量は、触
媒１Ｌあたり５〜１００ｇである。５ｇ未満だと貴金属
の分散性が得られず、１００ｇより多く使用しても前記
改良効果は飽和し有効でない。The amount of the zirconium oxide used is 5 to 100 g per liter of the catalyst. If the amount is less than 5 g, the dispersibility of the noble metal cannot be obtained, and even if the amount is more than 100 g, the improvement effect is saturated and not effective.
【００２８】このように、ネオジウム及びカルシウムの
組成比を特定したジルコニウム酸化物とすることによっ
て、添加した元素がジルコニウム酸化物の結晶構造中に
容易に固溶し、しかも、高温下での構造安定性が向上
し、大きなＢＥＴ比表面積のジルコニウム酸化物を得る
ことができる。As described above, by using a zirconium oxide having a specified composition ratio of neodymium and calcium, the added element easily forms a solid solution in the crystal structure of the zirconium oxide, and furthermore, has a stable structure at high temperatures. Properties can be improved, and a zirconium oxide having a large BET specific surface area can be obtained.
【００２９】特に請求項３記載の排気ガス浄化用触媒
は、請求項１又は２記載の排気ガス浄化用触媒の高温耐
久後の浄化性能を特に高めるために、プラセオジウム、
イットリウム、ランタン及びネオジウムからなる群より
選ばれた少なくとも一種の元素と、セリウムとを含有す
るもので、かかるジルコニウム酸化物の組成は、次の式
〔Ｘ〕e Ｃｅf Ｚｒg Ｏh で表され、前記式中、ｅ＝
０．０１〜１０モル％、ｆ＝５〜３０モル％、ｇ＝６５
〜９５モル％である。In particular, the exhaust gas purifying catalyst according to claim 3 is preferably praseodymium, in order to particularly enhance the purifying performance after high-temperature durability of the exhaust gas purifying catalyst according to claim 1 or 2.
Yttrium, and at least one element selected from the group consisting of lanthanum and neodymium, those containing cerium, the composition of such zirconium oxide, represented by the following formula [X] e Ce f Zr g O h , Where e =
0.01 to 10 mol%, f = 5 to 30 mol%, g = 65
~ 95 mol%.
【００３０】ｅ＝０．０１モル％未満では、Ｚｒ０2 の
みの場合と変わらず、上記した元素のＺｒ０2 のＢＥＴ
比表面積や熱安定性を改良する効果が現れず、ｅ＝１０
モル％を越えるとこの効果が飽和もしくは逆に低下す
る。[0030] In the e = less than 0.01 mol%, unchanged from the case of only Zr0 2, Zr0 2 of BET of the above-mentioned elements
The effect of improving the specific surface area and the thermal stability does not appear, and e = 10
If it exceeds mol%, this effect is saturated or conversely decreases.
【００３１】ｆ＝５モル％未満ではセリウムの酸素吸蔵
能が充分に発現せず、耐久後のロジウムや白金の浄化性
能の改良効果が十分に得られず、逆に、ｆ＝３０モル％
を越えると、この効果が飽和もしくは逆に結晶構造の熱
安定性が低下する。When f is less than 5 mol%, the oxygen storage capacity of cerium is not sufficiently exhibited, and the effect of improving the purification performance of rhodium and platinum after durability cannot be sufficiently obtained.
Is exceeded, this effect is saturated, or conversely, the thermal stability of the crystal structure decreases.
【００３２】かかるジルコニウム酸化物の使用量は、触
媒１Ｌあたり５〜１００ｇである。５ｇ未満だと充分な
貴金属の分散性が得られず、１００ｇより多く使用して
も改良効果は飽和し有効でない。The amount of the zirconium oxide used is 5 to 100 g per liter of the catalyst. If the amount is less than 5 g, sufficient dispersibility of the noble metal cannot be obtained, and even if the amount is more than 100 g, the improvement effect is saturated and not effective.
【００３３】このように、プラセオジウム、イットリウ
ム、ランタン及びネオジウムからなる群より選ばれた少
なくとも一種の元素とセリウムの組成比を特定したジル
コニウム酸化物とすることによって、添加した元素がジ
ルコニウム酸化物の結晶構造中に容易に固溶し高温下で
の構造安定性が向上し、しかも、酸素吸蔵能の高いジル
コニウム酸化物を得ることができる。As described above, the zirconium oxide having a specific composition ratio of cerium and at least one element selected from the group consisting of praseodymium, yttrium, lanthanum, and neodymium is used. It is possible to obtain a zirconium oxide which easily dissolves in the structure, improves the structural stability at high temperatures, and has a high oxygen storage capacity.
【００３４】このように、酸素吸蔵能の高いセリウム含
有ジルコニウム酸化物に白金を担持することによって、
リッチ雰囲気及びストイキ近傍で格子酸素や吸着酸素を
放出し易くなるため、ロジウムの酸化状態を排気ガスの
浄化に適したものとし、ロジウムの触媒能の低下を抑制
できる。As described above, by supporting platinum on a cerium-containing zirconium oxide having a high oxygen storage capacity,
Since it becomes easy to release lattice oxygen and adsorbed oxygen in a rich atmosphere and in the vicinity of stoichiometry, the oxidation state of rhodium can be made suitable for purifying exhaust gas, and a decrease in the catalytic ability of rhodium can be suppressed.
【００３５】また、請求項４記載の排気ガス浄化用触媒
は、請求項１〜３いずれかの項記載の排気ガス浄化用触
媒に加えて、更に、パラジウム担持アルミナを含有する
ものである。当該パラジウムの含有量は、触媒１Ｌ容量
中０．１〜２０ｇである。０．０１ｇ未満では低温活性
や浄化性能が十分に発現せず、逆に２０ｇを越えてもパ
ラジウムの触媒活性は飽和し、経済的にも有効でない。The exhaust gas purifying catalyst according to a fourth aspect further includes, in addition to the exhaust gas purifying catalyst according to any one of the first to third aspects, palladium-supported alumina. The content of the palladium is 0.1 to 20 g in 1 L of the catalyst. If it is less than 0.01 g, the low-temperature activity and purification performance are not sufficiently exhibited, and if it exceeds 20 g, the catalytic activity of palladium is saturated, and it is not economically effective.
【００３６】前記パラジウムが担持される基材として
は、白金やパラジウムの分散性を高め、触媒性能を向上
させるため、アルミナ、特に活性アルミナが適切であ
る。特に、高温耐久後のアルミナの構造安定性を高め、
α−アルミナへの相転移やＢＥＴ比表面積の低下を抑制
するために、上記アルミナにはセリウム、ジルコニウム
及びランタンからなる群より選ばれた少なくとも一種が
金属換算で１〜１０モル％含有される。As the substrate on which the palladium is supported, alumina, particularly activated alumina, is suitable in order to enhance the dispersibility of platinum and palladium and to improve the catalytic performance. In particular, enhance the structural stability of alumina after high-temperature durability,
In order to suppress the phase transition to α-alumina and the decrease in the BET specific surface area, the alumina contains 1 to 10 mol% of at least one selected from the group consisting of cerium, zirconium and lanthanum in terms of metal.
【００３７】かかるアルミナの使用量は、触媒１Ｌあた
り１０〜２００ｇである。１０ｇ未満だと充分な貴金属
の分散性が得られず、２００ｇより多く使用しても触媒
性能は飽和し、顕著な改良効果は得られない。The amount of the alumina used is 10 to 200 g per liter of the catalyst. If the amount is less than 10 g, sufficient dispersibility of the noble metal cannot be obtained, and even if the amount is more than 200 g, the catalytic performance is saturated, and a remarkable improvement effect cannot be obtained.
【００３８】これにより、スラリー化した触媒成分担持
層のコーティング性を改善でき、しかも、触媒成分層の
剥離を防止することができる。This makes it possible to improve the coating property of the catalyst component supporting layer which has been slurried, and to prevent the catalyst component layer from peeling off.
【００３９】更に、請求項５記載の排気ガス浄化用触媒
は、請求項１〜４いずれかの項記載の排気ガス浄化用触
媒に、更に、パラジウム担持セリウム酸化物を含有する
ものである。当該セリウム酸化物には、ジルコニウム、
ネノジウム及びランタンからなる群より選ばれた少なく
とも一種を金属換算で１〜４０モル％、セリウムを６０
〜９８モル％含有もるのである。１〜４０モル％とした
のは、セリウム酸化物（ＣｅＯ2 ）にジルコニウム、ネ
オジウム及びランタンからなる群より選ばれた少なくと
も一種の元素を添加し、ＣｅＯ2 の酸素放出能やＢＥＴ
比表面積、熱安定性を顕著に改良するためである。１モ
ル％未満ではＣｅＯ2 のみの場合と変わらず、上記した
元素の添加効果が現れず、４０モル％を超えるとこの効
果が飽和もしくは逆に低下する。Further, an exhaust gas purifying catalyst according to a fifth aspect is the exhaust gas purifying catalyst according to any one of the first to fourth aspects, further comprising cerium oxide carrying palladium. The cerium oxide includes zirconium,
At least one selected from the group consisting of nenodium and lanthanum is 1 to 40 mol% in terms of metal, and cerium is 60%.
９８98 mol%. The reason for setting the content to 1 to 40 mol% is that at least one element selected from the group consisting of zirconium, neodymium and lanthanum is added to cerium oxide (CeO 2 ), and the oxygen releasing ability and BET of CeO 2 are added.
This is for remarkably improving the specific surface area and the thermal stability. If it is less than 1 mol%, the effect of adding the above-mentioned element does not appear as in the case of only CeO 2 , and if it exceeds 40 mol%, this effect is saturated or conversely decreases.
【００４０】これにより、高温耐久後の低温活性及びＨ
Ｃ浄化能を向上させることができる。Thus, the low-temperature activity after high-temperature durability and H
C Purification ability can be improved.
【００４１】請求項６記載の排気ガス浄化用触媒は、請
求項４又は５記載の排気ガス浄化用触媒において、上記
パラジウム含有触媒成分をコート層の内層側（下側）に
配置し、前記ロジウム担持ジルコニウム酸化物をコート
表層側（上側）に配置したものである。上記パラジウム
含有触媒成分とは、上記パラジウム担持アルミナ、又
は、上記パラジウム担持アルミナと上記パラジウム担持
セリウム酸化物である。このような配置とすることによ
り、ロジウムとパラジウムの間の耐被毒性向上という相
乗作用が効率良く発現することとなる。According to a sixth aspect of the present invention, there is provided the exhaust gas purifying catalyst according to the fourth or fifth aspect, wherein the palladium-containing catalyst component is disposed on the inner layer side (lower side) of the coat layer. This is one in which the supported zirconium oxide is disposed on the surface side (upper side) of the coat. The palladium-containing catalyst component is the palladium-supported alumina or the palladium-supported alumina and the palladium-supported cerium oxide. With such an arrangement, a synergistic effect of improving the resistance to poisoning between rhodium and palladium is efficiently exhibited.
【００４２】また、請求項７記載の排気ガス浄化触媒
は、請求項１〜６いずれかの項記載の排気ガス浄化用触
媒に、更にアルカリ金属及びアルカリ土類金属からなる
群より選ばれる少なくとも一種を含有するものである。
使用されるアルカリ金属及び／又はアルカリ土類金属に
は、リチウム、ナトリウム、カリウム、セシウム、マグ
ネシウム、カルシウム、ストロンチウム、バリウムが含
まれる。その含有量は触媒１Ｌ中１〜４０ｇである。１
ｇ未満では、炭化水素類の吸着被毒やパラジウムのシン
タリングを抑制できず、４０ｇを越えても有為な増量効
果が得られず逆に性能を低下させる。The exhaust gas purifying catalyst according to claim 7 is the same as the exhaust gas purifying catalyst according to any one of claims 1 to 6, further comprising at least one selected from the group consisting of alkali metals and alkaline earth metals. It contains.
The alkali metals and / or alkaline earth metals used include lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium. Its content is 1 to 40 g per liter of catalyst. 1
If it is less than g, adsorption poisoning of hydrocarbons and sintering of palladium cannot be suppressed, and if it exceeds 40 g, a significant effect of increasing the amount cannot be obtained, and conversely, the performance is reduced.
【００４３】このように、アルカリ金属及びアルカリ土
類金属からなる群より選ばれた少なくとも一種を含有す
ることにより更に、浄化性能向上効果が得られる。これ
らを触媒成分担持層に含有させると、リッチ雰囲気下で
のＨＣ吸着被退く作用を緩和し、また、パラジウムのシ
ンタリングを抑制するため、低温活性や還元雰囲気でＮ
Ｏx 浄化能をさらに向上させることができる。As described above, by containing at least one selected from the group consisting of alkali metals and alkaline earth metals, the effect of improving purification performance can be further obtained. When these are contained in the catalyst component-supporting layer, the action of desorbing HC by adsorption in a rich atmosphere is reduced, and sintering of palladium is suppressed.
Ox purification ability can be further improved.
【００４４】本発明の排気ガス浄化用触媒を製造するに
際しては、上記ジルコニウム酸化物を構成する添加元素
とジルコニウム成分を各々含む触媒原料を純水に加えて
攪拌する。この際、各触媒原料を同時に又は別個に溶解
した液を加えても良い。In producing the exhaust gas purifying catalyst of the present invention, a catalyst raw material containing the zirconium oxide and the additional element constituting the zirconium oxide is added to pure water and stirred. At this time, a liquid in which each catalyst raw material is dissolved simultaneously or separately may be added.
【００４５】次いで、この混合溶液にアンモニア水及び
アンモニウム化合物の水溶液を徐々に添加し、溶液のｐ
Ｈを６．０〜１０．０の範囲になるように調整した後、
水分を除去し、残留物を熱処理してジルコニウム酸化物
を得、これにロジウム及び／又は白金を含浸担持してさ
らに熱処理することにより請求項１〜３いずれかの項記
載の排気ガス浄化用触媒が得られる。Next, an aqueous ammonia solution and an aqueous solution of an ammonium compound are gradually added to the mixed solution, and p
After adjusting H to be in the range of 6.0 to 10.0,
The exhaust gas purifying catalyst according to any one of claims 1 to 3, wherein water is removed and the residue is heat-treated to obtain a zirconium oxide, which is further impregnated with rhodium and / or platinum and further heat-treated. Is obtained.
【００４６】請求項１〜３いずれかの項記載の排気ガス
浄化用触媒のジルコニウム酸化物は、前記添加元素とジ
ルコニウム成分の各水溶液塩を水に溶解又は分散させた
後、アンモニア水あるいはアンモニウム化合物の水溶液
を加え、溶液のｐＨを６．０から１０．０の範囲になる
ように調整になるように調整した後、水分を除去して乾
燥し、次いで焼成することにより得られる。The zirconium oxide of the exhaust gas purifying catalyst according to any one of claims 1 to 3, wherein the aqueous solution salt of the additive element and the zirconium component is dissolved or dispersed in water, and then the aqueous ammonia or the ammonium compound is used. And then adjusting the pH of the solution to be in the range of 6.0 to 10.0, removing water, drying, and then firing.
【００４７】または、請求項１〜３いずれかの項記載の
排気ガス浄化用触媒のジルコニウム酸化物は、予めジル
コニウム酸化物の沈殿を生成した懸濁液に、前記添加元
素の水溶液塩を水に溶解又は分散させた溶液を徐々に滴
下した後、溶液のｐＨを６．０から１０．０の範囲にな
るように調整し、水分を除去して乾燥し、次いで焼成す
ることにより得ることもできる。Alternatively, the zirconium oxide of the catalyst for purifying exhaust gas according to any one of claims 1 to 3, may be obtained by converting an aqueous solution salt of the additional element into water in a suspension in which a precipitate of zirconium oxide is previously generated. After the dissolved or dispersed solution is gradually dropped, the pH of the solution is adjusted to be in a range of 6.0 to 10.0, moisture is removed, dried, and then calcined. .
【００４８】本発明の排気ガス浄化用触媒に用いるジル
コニウム酸化物は、前記各元素の硝酸塩、炭酸塩、酢酸
塩及び酸化物等の水溶性塩を任意に組み合わせて製造す
ることができる。The zirconium oxide used in the exhaust gas purifying catalyst of the present invention can be produced by arbitrarily combining water-soluble salts such as nitrates, carbonates, acetates and oxides of the above-mentioned elements.
【００４９】前記ジルコニウム酸化物の調製方法として
は特別な方法に限定されず、成分の著しい偏在を伴わな
い限り、公知の沈殿法、含浸法、蒸発乾固法等の種々の
方法の手化から適宜選択して使用することができるが、
上記各元素の塩を水に溶解又は分散させた後、アンモニ
ア水あるいはアンモニウム化合物の水溶液を沈殿剤とし
て加える沈殿法を用いることが、ジルコニウム酸化物の
結晶構造を均一にし、また、表面積を充分に確保するた
めに好ましい。The method for preparing the above-mentioned zirconium oxide is not limited to a special method, but may be any one of various known methods such as a precipitation method, an impregnation method and an evaporation to dryness method, unless there is a significant uneven distribution of components. It can be selected and used as appropriate,
After dissolving or dispersing the salt of each of the above elements in water, using a precipitation method in which an aqueous solution of ammonia water or an ammonium compound is used as a precipitant, the crystal structure of the zirconium oxide is made uniform, and the surface area is sufficiently increased. It is preferable to secure.
【００５０】上記沈殿法を実施するに際しては、溶液の
ｐＨを６．０〜１０．０の範囲に調整することにより、
各種金属塩の沈殿物を形成することができる。ｐＨが
６．０より低いと各種元素が充分に沈殿を形成させず、
逆にｐＨが１０．０より高いと沈殿した成分の一部が再
溶解することがある。In carrying out the precipitation method, the pH of the solution is adjusted to a range of 6.0 to 10.0,
Precipitates of various metal salts can be formed. When the pH is lower than 6.0, various elements do not sufficiently form a precipitate,
Conversely, if the pH is higher than 10.0, some of the precipitated components may be redissolved.
【００５１】水の除去は、例えば濾過法や蒸発乾固法の
公知の方法の中から適宜選択して行うことができる。本
発明に用いるジルコニウム酸化物を得るために最初の熱
処理は、特に制限されないが、添加した元素をジルコニ
ウム酸化物に固溶させた複合酸化物を形成し、また、ロ
ジウムや白金の分散性良く担持するための大木な比表面
積を得るため、例えば４００℃〜８００℃の比較的低温
で空気中及び／又は空気流通下で焼成を行うこと好まし
い。The removal of water can be appropriately selected from known methods such as a filtration method and an evaporation to dryness method. The first heat treatment for obtaining the zirconium oxide used in the present invention is not particularly limited, but forms a complex oxide in which the added element is dissolved in the zirconium oxide, and also supports rhodium and platinum with good dispersibility. In order to obtain a large specific surface area for sintering, it is preferable to perform calcination at a relatively low temperature of, for example, 400 ° C. to 800 ° C. in the air and / or under the flow of air.
【００５２】前記ジルコニウム酸化物にロジウムや白金
を担持する方法としては、例えば含浸法や混練法等の公
知の方法の中から適宜選択して行うことができるが、特
に含浸法を用いることが好ましい。The method of supporting rhodium or platinum on the zirconium oxide can be appropriately selected from known methods such as an impregnation method and a kneading method, but it is particularly preferable to use the impregnation method. .
【００５３】ロジウムの原料化合物としては、硝酸塩等
の水溶性のものであれば任意のものが使用できる。白金
の原料化合物としては、ジニトロジアンミン酸塩、塩化
物、硝酸塩等の水溶性のものであれば任意のものが使用
できる。As a raw material compound of rhodium, any compound can be used as long as it is water-soluble such as nitrate. As the raw material compound for platinum, any compound can be used as long as it is a water-soluble compound such as dinitrodiamminate, chloride, and nitrate.
【００５４】本発明にかかる排気ガス浄化用触媒は、沈
殿法で得られたジルコニウム酸化物が有する微細な細孔
構造と大きなＢＥＴ比表面積及び均一な結晶構造が、低
温におけるロジウムの触媒活性の発現に重要な役割を果
たしている。これに対し、上記沈殿法を用いずに得たジ
ルコニウム酸化物は、反応に有効な比表面積が小さくな
り、また、添加した元素がジルコニウム酸化物に固溶し
た複合酸化物を形成せず担持表面に偏在し、ロジウムや
白金の触媒活性や耐久後の浄化性能が低下する。In the exhaust gas purifying catalyst according to the present invention, the fine pore structure, large BET specific surface area and uniform crystal structure of the zirconium oxide obtained by the precipitation method exhibit the catalytic activity of rhodium at a low temperature. Plays an important role. On the other hand, zirconium oxide obtained without using the above precipitation method has a small specific surface area effective for the reaction, and does not form a complex oxide in which the added element is dissolved in the zirconium oxide. And the catalytic activity of rhodium and platinum and the purification performance after durability are reduced.
【００５５】また、請求項１〜３記載の排気ガス浄化用
触媒中の触媒成分に加えて、アルミナ粉末にパラジウム
を含浸法で担持した粉末を加えることにより、請求項４
記載の排気ガス浄化用触媒が得られる。パラジウムの原
料化合物としては、ジニトロジアンミン酸塩、塩化物、
硝酸塩等水溶性のものであれば任意のものが使用でき
る。Further, in addition to the catalyst component in the exhaust gas purifying catalyst according to any one of claims 1 to 3, a powder obtained by impregnating palladium on alumina powder is added.
An exhaust gas purifying catalyst as described is obtained. Raw material compounds of palladium include dinitrodiamminate, chloride,
Any water-soluble substance such as nitrate can be used.
【００５６】また、請求項１〜４記載の排気ガス浄化用
触媒中の触媒成分に加えて、セリウム酸化物粉末にパラ
ジウムを含浸法で担持した粉末を加えることにより、請
求項５記載の排気ガス浄化用触媒が得られる。また、該
セリウム酸化物には、ジルコニウム、ネオジウム及びラ
ンタンからなる群より選ばれる少なくとも１種が含有さ
れる。当該ジルコニウム、ネオジウム及びランタンから
なる群より選ばれる少なくとも一種を含有するセリウム
酸化物にパラジウムが担持されたものを添加することに
より、還元雰囲気下において、パラジウムの酸化状態
を、排気ガス浄化に適した状態に、より有効に維持する
ことができる。Further, in addition to the catalyst component in the exhaust gas purifying catalyst according to any one of claims 1 to 4, a powder obtained by impregnating cerium oxide powder with palladium by impregnation is added. A purification catalyst is obtained. The cerium oxide contains at least one selected from the group consisting of zirconium, neodymium and lanthanum. The zirconium, neodymium and lanthanum by adding a palladium-supported cerium oxide containing at least one selected from the group consisting of, under a reducing atmosphere, the oxidation state of palladium, suitable for exhaust gas purification State can be maintained more effectively.
【００５７】このようにして得られる本発明にかかる排
気ガス浄化用触媒は、無担体でも有効に使用することが
できるが、粉砕・スラリーとし、触媒担体にコートし
て、４００〜９００℃で焼成して用いることが好まし
い。The exhaust gas purifying catalyst according to the present invention thus obtained can be effectively used without a carrier. However, it is pulverized and slurry, coated on the catalyst carrier and calcined at 400 to 900 ° C. It is preferable to use them.
【００５８】従って、得られた前記ロジウム及び／又は
白金担持ジルコニウム酸化物粉末、上記パラジウム担体
アルミナ粉末及び上記パラジウム担持セリウム酸化物粉
末に、アルミナゾルを加えて湿式にて粉砕してスラリー
とし、触媒担体に付着させ、４００〜６５０℃の範囲の
温度で空気中及び／又は空気流通下で焼成を行う。Therefore, alumina sol was added to the obtained rhodium and / or platinum-supported zirconium oxide powder, the above-mentioned palladium-supported alumina powder and the above-mentioned palladium-supported cerium oxide powder, and wet-milled to obtain a slurry. And calcined at a temperature in the range of 400 to 650 ° C. in the air and / or under a flow of air.
【００５９】更に、ロジウム及びパラジウムの耐被毒性
向上という相乗作用を効率よく発現させるために、パラ
ジウムを含有する触媒成分層はコート層の下側（内層
側）に配置し、ロジウムを含有する触媒成分層はコート
層の上側（表層側）に配置することが好ましく、これに
より請求項６記載の排気ガス浄化用触媒が得られる。白
金は、ロジウムを含有する触媒成分層（表層側）及びパ
ラジウムを含有する触媒成分層（内層側）いずれの触媒
成分層中に含有させることもできるが、特に、ロジウム
を含有する触媒成分層（表層側）中に均一に配置するこ
とが耐久性改良の点から好ましい。Further, in order to efficiently exhibit the synergistic effect of improving the poisoning resistance of rhodium and palladium, the palladium-containing catalyst component layer is disposed below the coat layer (inner layer side), and the rhodium-containing catalyst is provided. The component layer is preferably disposed on the upper side (surface side) of the coat layer, whereby the exhaust gas purifying catalyst according to claim 6 is obtained. Platinum can be contained in any of the catalyst component layers containing rhodium (surface layer side) and the catalyst component layer containing palladium (inner layer side). In particular, the catalyst component layer containing rhodium ( It is preferable to arrange them uniformly in the surface layer) from the viewpoint of improving durability.
【００６０】触媒担体としては、公知の触媒担体の中か
ら適宜選択して使用することができ、例えば耐火性材料
からなるモノリス担体やメタル担体等が挙げられる。前
記触媒担体の形状は、特に制限されないが、通常はハニ
カム形状で使用することが好ましく、ハニカム状の各種
基材に触媒粉末を塗布して用いられる。The catalyst carrier can be appropriately selected from known catalyst carriers and used, and examples thereof include a monolith carrier made of a refractory material and a metal carrier. Although the shape of the catalyst carrier is not particularly limited, it is generally preferable to use the catalyst carrier in a honeycomb shape. The catalyst carrier is used by applying a catalyst powder to various honeycomb base materials.
【００６１】このハニカム材料としては、一般にセラミ
ック等のコージェライト質のものが多く用いられるが、
フェライト系ステンレス等の金属材料からなるハニカム
材料を用いることも可能であり、更には触媒成分粉末そ
のものをハニカム状に成形しても良い。触媒の形状をハ
ニカム状とすることにより、触媒と排気ガスとの接触面
積が大きくなり、圧力損失も抑制できるため自動車用排
気ガス浄化用触媒として用いる場合に極めて有効であ
る。As the honeycomb material, cordierite materials such as ceramics are generally used.
It is also possible to use a honeycomb material made of a metal material such as ferrite stainless steel, and further, the catalyst component powder itself may be formed into a honeycomb shape. By making the shape of the catalyst into a honeycomb shape, the contact area between the catalyst and the exhaust gas is increased and the pressure loss can be suppressed, so that it is extremely effective when used as an exhaust gas purifying catalyst for automobiles.
【００６２】ハニカム材料に付着させる触媒成分コート
層の量は、触媒成分全体のトータルで、触媒１Ｌあた
り、５０ｇ〜４００ｇが好ましい。触媒成分担持層が多
い程、触媒寿命の面から好ましいが、コート層が厚くあ
りすぎると、触媒成分担持層内部で反応ガスが拡散不良
となり触媒と充分に接触できなくなるため、活性に対す
る増量効果が飽和し、更にはガスの通過抵抗も大きくな
ってしまう。このため、コート層量は、上記触媒１Ｌあ
たり５０ｇ〜４００ｇが好ましい。The amount of the catalyst component coat layer adhered to the honeycomb material is preferably 50 g to 400 g per liter of the catalyst in total of the entire catalyst components. The larger the number of catalyst component-supporting layers, the more preferable in terms of catalyst life.However, if the coating layer is too thick, the reaction gas cannot be sufficiently contacted with the catalyst due to poor diffusion of the reaction gas inside the catalyst component-supporting layer. It saturates and further increases the gas passage resistance. Therefore, the amount of the coat layer is preferably 50 g to 400 g per liter of the catalyst.
【００６３】更に好ましくは、得られた排気ガス浄化用
触媒に、アルカリ金属及びアルカリ土類金属を含浸担持
させることにより、請求項７記載の排気ガス浄化用触媒
が得られる。使用できるアルカリ金属及びアルカリ土類
金属は、リチウム、ナトリウム、カリウム、セシウム、
マグネシウム、カルシウム、ストロンチウからなる群よ
り選ばれる少なくとも一種の元素が挙げられるが、特
に、カリウム及び／又はバリウムが好ましい。More preferably, the obtained exhaust gas purifying catalyst is impregnated and supported with an alkali metal and an alkaline earth metal to obtain the exhaust gas purifying catalyst according to claim 7. Alkali metals and alkaline earth metals that can be used are lithium, sodium, potassium, cesium,
Examples include at least one element selected from the group consisting of magnesium, calcium, and strontium, with potassium and / or barium being particularly preferred.
【００６４】使用できるアルカリ金属及びアルカリ土類
金属の化合物は、酸化物、硝酸塩及び水酸化物等の水溶
性のものである。これにより、白金及びパラジウムの近
傍に塩基性元素であるアルカル金属及び／又はシルカリ
土類金属を分散性良く担持することが可能となる。The alkali metal and alkaline earth metal compounds that can be used are water-soluble compounds such as oxides, nitrates and hydroxides. This makes it possible to carry the alkali metal and / or the alkaline earth metal, which are basic elements, in the vicinity of platinum and palladium with good dispersibility.
【００６５】具体的には、アルカリ金属化合物及び／又
はアルカリ土類金属からなる粉末の水溶液を、ウォッシ
ュコート成分を担持した上記担体に含浸し、乾燥し、次
いで空気中及び／又は空気流通下で２００〜６００℃の
比較的低温で焼成するものである。かかる焼成温度が２
００℃未満だとアルカリ金属及びアルカリ土類金属化合
物が酸化物形態になることが充分にできず、逆に６００
℃を越えても焼成温度の効果は飽和し、顕著な差異は得
られない。Specifically, an aqueous solution of a powder comprising an alkali metal compound and / or an alkaline earth metal is impregnated into the above-mentioned carrier supporting a washcoat component, dried, and then dried in air and / or under a stream of air. It is fired at a relatively low temperature of 200 to 600 ° C. If the firing temperature is 2
If the temperature is lower than 00 ° C., the alkali metal and alkaline earth metal compounds cannot be sufficiently converted into the oxide form.
Even if the temperature exceeds ℃, the effect of the sintering temperature is saturated, and no remarkable difference is obtained.
【００６６】本発明を次の実施例及び比較例により説明
する。The present invention will be described with reference to the following examples and comparative examples.
【００６７】[0067]
【実施例】実施例１ セリウム３モル％（ＣｅＯ2 に換算して８．７重量
％）、ジルコニウム３モル％（ＺｒＯ2 に換算して６．
３重量％）とランタン２モル％（Ｌａ2 Ｏ3 に換算して
５．５重量％）を含有するアルミナ粉末（粉末Ａ）に硝
酸パラジウム水溶液を含浸し、１５０℃で１２時間乾燥
した後、４００℃で１時間焼成して、Ｐｄ担持アルミナ
粉末（粉末Ｂ）を得た。この粉末ＢのＰｄ濃度は４．８
重量％であった。 EXAMPLE 1 3 mol% of cerium (8.7 wt% in terms of CeO 2 ), 3 mol% of zirconium (in terms of ZrO 2 , 6.
Alumina powder (powder A) containing 3% by weight) and 2% by mole of lanthanum (5.5% by weight in terms of La 2 O 3 ) was impregnated with an aqueous palladium nitrate solution and dried at 150 ° C. for 12 hours. It was calcined at 400 ° C. for 1 hour to obtain Pd-supported alumina powder (powder B). The Pd concentration of this powder B was 4.8.
% By weight.
【００６８】ランタン１モル％（Ｌａ2 Ｏ3 に換算して
２重量％）とジルコニウム３２モル％（ＺｒＯ2 に換算
して２５重量％）を含むセリウム酸化物粉末（粉末Ｃ）
に硝酸パラジウム水溶液を含浸し、１５０℃で１２時間
乾燥した後、４００℃で１時間焼成して、Ｐｄ担持セリ
ウム酸化物（Ｌａ0.01Ｚｒ0.32Ｃｅ0.67Ｏx ）粉末（粉
末Ｄ）を得た。この粉末ＤのＰｄ濃度は０．９重量％で
あった。Cerium oxide powder (powder C) containing 1 mol% of lanthanum (2 wt% in terms of La 2 O 3 ) and 32 mol% of zirconium (25 wt% in terms of ZrO 2 )
Was impregnated with an aqueous solution of palladium nitrate, dried at 150 ° C. for 12 hours, and calcined at 400 ° C. for 1 hour to obtain Pd-supported cerium oxide (La 0.01 Zr 0.32 Ce 0.67 O x ) powder (powder D). The Pd concentration of this powder D was 0.9% by weight.
【００６９】上記粉末Ｂ９０７ｇ、粉末Ｄ４００ｇと活
性アルミナ１９３ｇ、硝酸水溶液１０００ｇを磁性ボー
ルミルに投入し、混合・粉砕してスラリーを得た。この
スラリー液をコージェラト質モノリス担体（１．７Ｌ、
４００セル）に付着させ、空気流にてセル内の余剰のス
ラリーを除去・乾燥し、４００℃で１時間焼成した。こ
の作業を２度行い、コート層重量１５０ｇ／Ｌ一担体
（担体Ａ）を得た。パラジウム担持量は１３３．３ｇ／
ｃｆ（４．７１ｇ／Ｌ）であった。907 g of the powder B, 400 g of powder D, 193 g of activated alumina, and 1000 g of an aqueous nitric acid solution were charged into a magnetic ball mill, mixed and pulverized to obtain a slurry. This slurry liquid is applied to a cordieritic monolith carrier (1.7 L,
(400 cells), the excess slurry in the cells was removed by an air stream, dried, and fired at 400 ° C. for 1 hour. This operation was performed twice to obtain a coat layer weight of 150 g / L per carrier (carrier A). The amount of palladium carried was 133.3 g /
cf (4.71 g / L).
【００７０】Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８
０モル％のジルコニウム酸化物粉末（粉末Ｅ）に硝酸ロ
ジウム水溶液を含浸し、１５０℃で１２時間乾燥した
後、４００℃で１時間焼成して、Ｒｈ担持Ｎｄ0.1 Ｃａ
0.1 Ｚｒ0.8 Ｏx 粉末（粉末Ｆ）を得た。この粉末Ｆの
Ｒｈ濃度は１．５重量％であった。Nd 10 mol%, Ca 10 mol%, Zr8
A 0 mol% zirconium oxide powder (powder E) is impregnated with an aqueous solution of rhodium nitrate, dried at 150 ° C. for 12 hours, and calcined at 400 ° C. for 1 hour to obtain Rh-supported Nd 0.1 Ca
A 0.1 Zr 0.8 O x powder (powder F) was obtained. The Rh concentration of this powder F was 1.5% by weight.
【００７１】Ｌａ１モル％、Ｃｅ２０モル％、Ｚｒ７９
モル％のジルコニウム酸化物粉末（粉末Ｇ）にジニトロ
ジアンミン酸白金水溶液を含浸し、１５０℃で１２時間
乾燥した後、４００℃で１時間焼成してＰｔ担持ジルコ
ニウム酸化物粉末（粉末Ｈ）を得た。この粉末ＨのＰｔ
濃度は１．５重量％であった。La 1 mol%, Ce 20 mol%, Zr 79
Molar% zirconium oxide powder (powder G) is impregnated with an aqueous solution of platinum dinitrodiamminate, dried at 150 ° C. for 12 hours, and calcined at 400 ° C. for 1 hour to obtain a Pt-supported zirconium oxide powder (powder H). Was. Pt of this powder H
The concentration was 1.5% by weight.
【００７２】上記粉末Ｆ３１３ｇ、粉末Ｈ３１３ｇと、
ジルコニウム３モル％（ＺｒＯ2 に換算して６．３重量
％）とを含むアルミナ粉末（粉末Ｉ）１４９ｇと活性ア
ルミナ２５ｇ、硝酸水溶液１０００ｇを磁性ボールミル
に投入し、混合・粉砕してスラリーを得た。このスラリ
ー液を前記Ｐｄ含有触媒成分層を担持したコージェラト
質モノリス担体（１．７Ｌ、４００セル）（担持Ａ）に
付着させ、空気流にてセル内の余剰のスラリーを除去・
乾燥し、４００℃で１時間焼成した。コート層重量８０
ｇ／Ｌ一担体（担持Ｂ）を得た。Ｒｈの担持量は１３．
３ｇ／ｃｆ（０．４７ｇ／Ｌ）、Ｐｔの担持量は１３．
３ｇ／ｃｆ（０．４７ｇ／Ｌ）であった。次いで、上記
触媒成分担持コージェラト質モノリス担体（担持Ｂ）に
酢酸バリウム溶液を付着させた後、４００℃で１時間焼
成し、ＢａＯとして１０ｇ／Ｌを含有させて、排気ガス
浄化用触媒を得た。The above-mentioned powder F313g, powder H313g,
149 g of alumina powder (powder I) containing 3 mol% of zirconium (6.3% by weight in terms of ZrO 2 ), 25 g of activated alumina, and 1000 g of a nitric acid aqueous solution are put into a magnetic ball mill, mixed and pulverized to obtain a slurry. Was. This slurry liquid is adhered to a cordieritic monolith carrier (1.7 L, 400 cells) (support A) supporting the Pd-containing catalyst component layer, and excess slurry in the cells is removed by air flow.
It was dried and baked at 400 ° C. for 1 hour. Coat layer weight 80
g / L carrier (Support B) was obtained. The supported amount of Rh is 13.
3 g / cf (0.47 g / L), Pt loading 13.
It was 3 g / cf (0.47 g / L). Next, after a barium acetate solution was adhered to the above-mentioned catalyst component-carrying monolithic carrier (supported B), it was baked at 400 ° C. for 1 hour to contain 10 g / L as BaO to obtain an exhaust gas purifying catalyst. .
【００７３】実施例２ Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８０モル％のジ
ルコニウム酸化物粉末の代わりに、Ｎｄ５モル％、Ｃａ
１０モル％、Ｚｒ８５モル％のジルコニウム酸化物粉末
を用いた以外は、実施例１と同様にして排気ガス浄化用
触媒を得た。 Example 2 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr, 5 mol% of Nd,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 10 mol% and 85 mol% of Zr was used.
【００７４】実施例３ Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８０モル％のジ
ルコニウム酸化物粉末の代わりに、Ｎｄ２０モル％、Ｃ
ａ１０モル％、Ｚｒ７０モル％のジルコニウム酸化物粉
末を用いた以外は、実施例１と同様にして排気ガス浄化
用触媒を得た。 Example 3 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr, 20 mol% of Nd and C
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of a 10 mol% and Zr 70 mol% was used.
【００７５】実施例４ Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８０モル％のジ
ルコニウム酸化物粉末の代わりに、Ｎｄ５モル％、Ｃａ
５モル％、Ｚｒ９０モル％のジルコニウム酸化物粉末を
用いた以外は、実施例１と同様にして排気ガス浄化用触
媒を得た。 Example 4 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr, 5 mol% of Nd,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 5 mol% and Zr 90 mol% was used.
【００７６】実施例５ Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８０モル％のジ
ルコニウム酸化物粉末の代わりに、Ｎｄ５モル％、Ｃａ
２０モル％、Ｚｒ７５モル％のジルコニウム酸化物粉末
を用いた以外は、実施例１と同様にして排気ガス浄化用
触媒を得た。 Example 5 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr, 5 mol% of Nd,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 20 mol% and Zr 75 mol% was used.
【００７７】実施例６ Ｎｄ１０モル％、Ｃａ１０モル％、Ｚｒ８０モル％のジ
ルコニウム酸化物粉末の代わりに、Ｎｄ１５モル％、Ｃ
ａ１５モル％、Ｚｒ７０モル％のジルコニウム酸化物粉
末を用いた以外は、実施例１と同様にして排気ガス浄化
用触媒を得た。 Example 6 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr, 15 mol% of Nd and C
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of a 15 mol% and Zr 70 mol% was used.
【００７８】実施例７ Ｌａ１モル％、Ｃｅ２０モル％、Ｚｒ７９モル％のジル
コニウム酸化物粉末の代わりに、Ｌａ１モル％、Ｃｅ１
０モル％、Ｚｒ８９モル％のジルコニウム酸化物粉末を
用いた以外は、実施例１と同様にして排気ガス浄化用触
媒を得た。 Example 7 Instead of zirconium oxide powder of 1 mol% of La, 20 mol% of Ce and 79 mol% of Zr, 1 mol% of La, Ce 1
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1 except that zirconium oxide powder of 0 mol% and 89 mol% of Zr was used.
【００７９】実施例８ Ｌａ１モル％、Ｃｅ２０モル％、Ｚｒ７９モル％のジル
コニウム酸化物粉末の代わりに、Ｌａ１モル％、Ｃｅ３
０モル％、Ｚｒ６９モル％のジルコニウム酸化物粉末を
用いた以外は、実施例１と同様にして排気ガス浄化用触
媒を得た。 Example 8 Instead of zirconium oxide powder of 1 mol% of La, 20 mol% of Ce, and 79 mol% of Zr, 1 mol% of La, Ce 3
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 0 mol% and Zr 69 mol% was used.
【００８０】実施例９ 実施例１で得られた粉末Ｂ９０７ｇ、粉末Ｄ４００ｇ、
粉末Ｈ１５７ｇ、活性アルミナ３６ｇ、硝酸水溶液１０
００ｇを磁性ボールミルに投入し、混合・粉砕してスラ
リーを得た。このスラリー液をコージェラト質モノリス
担体（１．７Ｌ、４００セル）に付着させ、空気流にて
セル内の余剰のスラリーを除去・乾燥し、４００℃で１
時間焼成した。この作業を２度行い、コート層重量１５
０ｇ／Ｌの担体（担体Ｃ）を得た。パラジウム担持量は
１３３．３ｇ／ｃｆ（４．７１ｇ／Ｌ）、白金担持量
６．７ｇ／ｃｆ（０．２４ｇ／Ｌ）であった。 Example 9 907 g of powder B obtained in Example 1, 400 g of powder D,
Powder H157g, activated alumina 36g, nitric acid aqueous solution 10
00g was charged into a magnetic ball mill, mixed and pulverized to obtain a slurry. This slurry liquid was adhered to a cordieritic monolithic carrier (1.7 L, 400 cells), and the excess slurry in the cells was removed and dried with an air stream.
Fired for hours. This operation was performed twice, and the coat layer weight 15
0 g / L carrier (carrier C) was obtained. The supported amount of palladium was 133.3 g / cf (4.71 g / L), and the supported amount of platinum was 6.7 g / cf (0.24 g / L).
【００８１】実施例１で得られた粉末Ｆ３１３ｇ、粉末
Ｇ１５７ｇ、粉末Ｈ１５７ｇと、ジルコニウム３モル％
（ＺｒＯ2 に換算して６．３重量％）とを含むアルミナ
粉末（粉末Ｉ）１４８ｇと活性アルミナ２５ｇ、硝酸水
溶液１０００ｇを磁性ボールミルに投入し、混合・粉砕
してスラリーを得た。このスラリー液を前記ＰｄとＰｔ
含有触媒成分層を担持したコージェラト質モノリス担体
（１．７Ｌ、４００セル）（担体Ｃ）に付着させ、空気
流にてセル内の余剰のスラリーを除去・乾燥し、４００
℃で１時間焼成した。コート層重量８０ｇ／Ｌ一担体
（担体Ｄ）を得た。Ｒｈの担持量は１３．３ｇ／ｃｆ
（０．４７ｇ／Ｌ）、Ｐｔの担持量は６．７ｇ／ｃｆ
（０．２４ｇ／Ｌ）であった。次いで、上記触媒成分担
持コージェラト質モノリス担体（担体Ｄ）に酢酸バリウ
ム溶液を付着させた後、４００℃で１時間焼成し、Ｂａ
Ｏとして１０ｇ／Ｌを含有させた。313 g of powder F, 157 g of powder G, 157 g of powder H obtained in Example 1 and 3 mol% of zirconium
148 g of alumina powder (powder I) containing (6.3% by weight in terms of ZrO 2 ), 25 g of activated alumina, and 1000 g of an aqueous nitric acid solution were charged into a magnetic ball mill, mixed and pulverized to obtain a slurry. This slurry liquid is mixed with Pd and Pt.
The monolithic carrier (1.7 L, 400 cells) carrying the catalyst component layer (1.7 L, 400 cells) was adhered to the carrier (carrier C), and the excess slurry in the cells was removed by air flow and dried.
Calcination was carried out at ℃ for 1 hour. A coat layer weight of 80 g / L (carrier D) was obtained. The supported amount of Rh is 13.3 g / cf.
(0.47 g / L), the loading amount of Pt is 6.7 g / cf.
(0.24 g / L). Next, a barium acetate solution was adhered to the catalyst component-supported cogelato monolithic carrier (carrier D), and calcined at 400 ° C. for 1 hour to form Ba.
O was contained at 10 g / L.
【００８２】実施例１０ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ５モル％、Ｃａ１０モル％、Ｚｒ８５モル％の
ジルコニウム酸化物粉末を用いた以外は、実施例９と同
様にして排気ガス浄化用触媒を得た。 Example 10 A zirconium oxide powder of 5 mol% of Nd, 10 mol% of Ca and 85 mol% of Zr was used instead of a zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr when preparing powder F. Except for using, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００８３】実施例１１ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ２０モル％、Ｃａ１０モル％、Ｚｒ７０モル％
のジルコニウム酸化物粉末を用いた以外は、実施例９と
同様にして排気ガス浄化用触媒を得た。 Example 11 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr in preparing powder F, 20 mol% of Nd, 10 mol% of Ca and 70 mol% of Zr
Except that the zirconium oxide powder was used, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００８４】実施例１２ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ５モル％、Ｃａ５モル％、Ｚｒ９０モル％のジ
ルコニウム酸化物粉末を用いた以外は、実施例９と同様
にして排気ガス浄化用触媒を得た。 Example 12 A zirconium oxide powder of 5 mol% of Nd, 5 mol% of Ca, and 90 mol% of Zr was replaced with a zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr in preparing powder F. Except for using, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００８５】実施例１３ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ５モル％、Ｃａ２０モル％、Ｚｒ７５モル％の
ジルコニウム酸化物粉末を用いた以外は、実施例９と同
様にして排気ガス浄化用触媒を得た。 Example 13 A zirconium oxide powder of 5 mol% of Nd, 20 mol% of Ca and 75 mol% of Zr was used in place of the zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr in preparing powder F. Except for using, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００８６】実施例１４ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ１５モル％、Ｃａ１５モル％、Ｚｒ７０モル％
のジルコニウム酸化物粉末を用いた以外は、実施例９と
同様にして排気ガス浄化用触媒を得た。 Example 14 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr in preparing powder F, 15 mol% of Nd, 15 mol% of Ca and 70 mol% of Zr
Except that the zirconium oxide powder was used, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００８７】実施例１５ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｌａ１モル％Ｃｅ１０モル％Ｚｒ８９モル％のジルコニ
ウム酸化物粉末を用いた以外は、実施例９と同様にして
排気ガス浄化用触媒を得た。 Example 15 La 1 mol%, Ce 20 mol% when preparing powder G,
Instead of Zr 79 mol% zirconium oxide powder,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 9 except that zirconium oxide powder of La 1 mol% Ce 10 mol% Zr 89 mol% was used.
【００８８】実施例１６ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｌａ１モル％、Ｃｅ３０モル％、Ｚｒ６９モル％のジル
コニウム酸化物粉末を用いた以外は、実施例９と同様に
して排気ガス浄化用触媒を得た。 Example 16 La 1 mol%, Ce 20 mol% when preparing powder G,
Instead of Zr 79 mol% zirconium oxide powder,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 9, except that zirconium oxide powder of 1 mol% of La, 30 mol% of Ce, and 69 mol% of Zr was used.
【００８９】実施例１７ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｐｒ１モル％、Ｌｅ２０モル％、Ｚｒ７８モル％のジル
コニウム酸化物粉末を用いた以外は、実施例１と同様に
して排気ガス浄化用触媒を得た。 Example 17 La 1 mol%, Ce 20 mol% when preparing powder G,
Instead of Zr 79 mol% zirconium oxide powder,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 1 mol% of Pr, 20 mol% of Le, and 78 mol% of Zr was used.
【００９０】実施例１８ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｙ１モル％、Ｎｄ１モル％、Ｃｅ２０モル％、Ｚｒ７８
モル％のジルコニウム酸化物粉末を用いた以外は、実施
例９と同様にして排気ガス浄化用触媒を得た。 Example 18 La 1 mol%, Ce 20 mol% when preparing powder G,
Instead of Zr 79 mol% zirconium oxide powder,
Y 1 mol%, Nd 1 mol%, Ce 20 mol%, Zr78
An exhaust gas purifying catalyst was obtained in the same manner as in Example 9 except that zirconium oxide powder of mol% was used.
【００９１】実施例１９ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｐｒ１モル％、Ｎｄ１モル％、Ｙ１モル％、Ｌａ１モル
％、Ｃｅ１０モル％、Ｚｒ８６モル％のジルコニウム酸
化物粉末を用いた以外は、実施例１と同様にして排気ガ
ス浄化用触媒を得た。 Example 19 La 1 mol%, Ce 20 mol%, and
Instead of Zr 79 mol% zirconium oxide powder,
An exhaust gas purifying catalyst was obtained in the same manner as in Example 1, except that zirconium oxide powder of 1 mol% of Pr, 1 mol% of Nd, 1 mol% of Y, 1 mol% of La, 10 mol% of Ce, and 86 mol% of Zr was used.
【００９２】実施例２０ 粉末Ｇを調製する際のＬａ１モル％、Ｃｅ２０モル％、
Ｚｒ７９モル％のジルコニウム酸化物粉末の代わりに、
Ｐｒ１モル％、Ｎｄ１モル％、Ｌａ１モル％、Ｃｅ３０
モル％、Ｚｒ６６モル％のジルコニウム酸化物粉末を用
いた以外は、実施例９と同様にして排気ガス浄化用触媒
を得た。 Example 20 La 1 mol%, Ce 20 mol% when preparing powder G,
Instead of Zr 79 mol% zirconium oxide powder,
Pr 1 mol%, Nd 1 mol%, La 1 mol%, Ce30
Exhaust gas purifying catalyst was obtained in the same manner as in Example 9 except that zirconium oxide powder of mol% and Zr 66 mol% was used.
【００９３】比較例１ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、活性アルミナを用いた以外は、実施例１と同様にし
て排気ガス浄化用触媒を得た。 Comparative Example 1 Exhaust gas was prepared in the same manner as in Example 1 except that activated alumina was used instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr in preparing powder F. A purification catalyst was obtained.
【００９４】比較例２ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、ＺｒＯ2 を用いた以外は、実施例１と同様にして排
気ガス浄化用触媒を得た。 Comparative Example 2 Exhaust gas was prepared in the same manner as in Example 1 except that ZrO 2 was used in place of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr when preparing powder F. A purification catalyst was obtained.
【００９５】比較例３ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ２０モル％、Ｃａ３０モル％、Ｚｒ５０モル％
のジルコニウム酸化物粉末を用いた以外は、実施例１と
同様にして排気ガス浄化用触媒を得た。 Comparative Example 3 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr in preparing powder F, 20 mol% of Nd, 30 mol% of Ca and 50 mol% of Zr
Except that the zirconium oxide powder was used, an exhaust gas purifying catalyst was obtained in the same manner as in Example 1.
【００９６】比較例４ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、活性アルミナを用いた以外は、実施例９と同様にし
て排気ガス浄化用触媒を得た。 Comparative Example 4 Exhaust gas was prepared in the same manner as in Example 9 except that activated alumina was used instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr in preparing powder F. A purification catalyst was obtained.
【００９７】比較例５ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、ＺｒＯ2 を用いた以外は、実施例９と同様にして排
気ガス浄化用触媒を得た。 Comparative Example 5 Exhaust gas was prepared in the same manner as in Example 9 except that ZrO 2 was used in place of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca, and 80 mol% of Zr in preparing powder F. A purification catalyst was obtained.
【００９８】比較例６ 粉末Ｆを調製する際のＮｄ１０モル％、Ｃａ１０モル
％、Ｚｒ８０モル％のジルコニウム酸化物粉末の代わり
に、Ｎｄ２０モル％、Ｃａ３０モル％、Ｚｒ５０モル％
のジルコニウム酸化物粉末を用いた以外は、実施例９と
同様にして排気ガス浄化用触媒を得た。 Comparative Example 6 Instead of zirconium oxide powder of 10 mol% of Nd, 10 mol% of Ca and 80 mol% of Zr in preparing powder F, 20 mol% of Nd, 30 mol% of Ca and 50 mol% of Zr
Except that the zirconium oxide powder was used, an exhaust gas purifying catalyst was obtained in the same manner as in Example 9.
【００９９】上記実施例１〜２０及び比較例１〜６で得
られた排気ガス浄化用触媒中におけるロジウム、白金、
パラジウム、アルカリ金属及びアルカリ土類金属の含有
量を表１に示す。In the exhaust gas purifying catalysts obtained in the above Examples 1 to 20 and Comparative Examples 1 to 6, rhodium, platinum,
Table 1 shows the contents of palladium, alkali metals and alkaline earth metals.
【０１００】[0100]
【表１】 [Table 1]
【０１０１】試験例 前記実施例１〜２０及び比較例１〜６の排気ガス浄化用
触媒について、以下の耐久条件により耐久を行った後、
下記評価条件で触媒活性評価を行った。 Test Example The exhaust gas purifying catalysts of Examples 1 to 20 and Comparative Examples 1 to 6 were subjected to durability under the following durability conditions.
The catalyst activity was evaluated under the following evaluation conditions.
【０１０２】 耐久条件 エンジン排気量 ４４００ｃｃ 燃料 有鉛ガソリン（Ｐｄ５０ｍｇ／ｕｓｇ） 触媒入口ガス温度 ９００℃ 耐久時間 １００時間 入口ガス組成 ＣＯ ０．５±０．１％ Ｏ2 ０．５±０．１％ ＨＣ 約１１００ｐｐｍ ＮＯ １３００ｐｐｍ ＣＯ2 １５％ Ａ／Ｆ変動 ５５００回（周期６５秒／回） 周期：Ａ／Ｆ＝１４．６ ５５秒 燃料カット ５秒 リッチ スパイク ５秒 Endurance conditions Engine displacement 4400cc Fuel Leaded gasoline (Pd 50mg / usg) Catalyst inlet gas temperature 900 ° C Endurance time 100 hours Inlet gas composition CO 0.5 ± 0.1% O 2 0.5 ± 0.1% HC Approx. 1100 ppm NO 1300 ppm CO 2 15% A / F fluctuation 5500 times (65 seconds / cycle) Cycle: A / F = 14.655 seconds Fuel cut 5 seconds Rich spike 5 seconds
【０１０３】評価条件１：低温活性 エンジン排気量 ２０００ｃｃ 燃料 無鉛ガソリン 昇温速度 １０℃／分 測定温度範囲 １５０〜５００℃ 耐久後の各排気ガス浄化用触媒の低温活性を、ＨＣ、Ｃ
Ｏ及びＮＯx の転化率が５０％になった時の温度（Ｔ５
０／℃）で表し、その結果を表２に示す。 Evaluation condition 1: Low-temperature active engine displacement 2000 cc fuel Unleaded gasoline Heating rate 10 ° C./min Measurement temperature range 150-500 ° C. The low-temperature activity of each exhaust gas purifying catalyst after endurance was determined by HC, C
O and NO x temperature when the conversion reached 50% (T5
0 / ° C.), and the results are shown in Table 2.
【０１０４】 耐久後の各排気ガス浄化用触媒の浄化性能を、ストイキ
雰囲気におけるＨＣ、ＣＯ及びＮＯx の平均転化率
（％）を以下の式により決定し、その結果を表２に示
す。[0104] The purifying performance of the exhaust gas purifying catalyst after the durability test was determined HC, the average conversion rate (%) The following equation for CO and NO x at stoichiometric atmosphere, and the results are shown in Table 2.
【０１０５】[0105]
【数１】 (Equation 1)
【数２】 (Equation 2)
【数３】 (Equation 3)
【０１０６】[0106]
【表２】 [Table 2]
【０１０７】[0107]
【発明の効果】請求項１記載の排気ガス浄化用触媒は、
耐久性と耐被毒性に優れ、耐久後の低温活性及びストイ
キ転化率等の排気ガス浄化性能を向上させることができ
る。The exhaust gas purifying catalyst according to claim 1 is
It is excellent in durability and resistance to poisoning, and can improve exhaust gas purification performance such as low-temperature activity and stoichiometric conversion after durability.
【０１０８】請求項２記載の排気ガス浄化用触媒は、上
記効果に加えて、更にロジウムの不活性化を抑制し、耐
久後の触媒性能を向上させることができる。The exhaust gas purifying catalyst according to claim 2 can further suppress the inactivation of rhodium and improve the catalyst performance after the durability, in addition to the above effects.
【０１０９】請求項３記載の排気ガス浄化用触媒は、上
記効果に加えて、触媒成分の低下を抑制できる。The exhaust gas purifying catalyst according to the third aspect can suppress the reduction of the catalyst component in addition to the above effects.
【０１１０】請求項４記載の排気ガス浄化用触媒は、上
記効果に加えて、更に低温活性や浄化性能を向上し、触
媒成分の完全に起因する触媒性能の低下を抑制できる。The exhaust gas purifying catalyst according to the fourth aspect, in addition to the above effects, can further improve low-temperature activity and purifying performance, and can suppress a decrease in catalytic performance due to a complete catalytic component.
【０１１１】請求項５記載の排気ガス浄化用触媒は、上
記効果に加えて、更にパラジウムの還元による不活性化
を抑制し、更に耐久後の触媒性能の低下を抑制できる。In the exhaust gas purifying catalyst according to the fifth aspect, in addition to the above effects, the inactivation of palladium by reduction can be further suppressed, and the deterioration of the catalytic performance after durability can be suppressed.
【０１１２】請求項６記載の排気ガス浄化用触媒は、上
記効果に加えて、パラジウムの耐被毒性を向上し、更
に、ロジウムの耐久後の触媒性能の低下を抑制できる。The exhaust gas purifying catalyst according to claim 6 can improve the poisoning resistance of palladium in addition to the above-mentioned effects, and can suppress a decrease in catalytic performance of rhodium after durability.
【０１１３】請求項７記載の排気ガス浄化用触媒は、上
記効果に加えて、触媒成分中のパラジウムのシンタリン
グを抑制して、更に低温活性や浄化性能を向上させるこ
とができる。In the exhaust gas purifying catalyst according to the seventh aspect, in addition to the above effects, sintering of palladium in the catalyst component can be suppressed, and the low-temperature activity and the purifying performance can be further improved.
Claims (7)
において、少なくともロジウム担持ジルコニウム酸化物
と白金担持ジルコニウム酸化物とを含有することを特徴
とする排気ガス浄化用触媒。1. An exhaust gas purifying catalyst, comprising: a monolithic catalyst having a catalyst component-supporting layer, comprising at least rhodium-supported zirconium oxide and platinum-supported zirconium oxide.
いて、ロジウムを担持するジルコニウム酸化物は、次の
一般式； Ｎｄa Ｃａb Ｚｒc Ｏd （式中、ａ，ｂ及びｃは、各元素の原子比率を示し、金
属換算で、ａ＝０．０１〜２０モル％、ｂ＝０．０５〜
２０モル％、ｃ＝６０〜９５モル％、ｄは上記各成分の
原子価を満足するのに必要な酸素原子数である）で表さ
れることを特徴とする排気ガス浄化用触媒。2. A catalyst for purifying exhaust gases according to claim 1, zirconium oxide carrying rhodium, the following general formula: in Nd a Ca b Zr c O d ( wherein, a, b and c, Indicates the atomic ratio of each element, a = 0.01 to 20 mol%, b = 0.05 to
20 mol%, c = 60 to 95 mol%, and d is the number of oxygen atoms required to satisfy the valence of each of the above components).
媒において、白金を担持するジルコニウム酸化物は、次
の一般式； 〔Ｘ〕 eＣｅf Ｚｒg Ｏh （式中、Ｘは、プラセオジウム、イットリウム、ランタ
ン及びネオジウムからなる群より選ばれた少なくとも一
種の元素であり、ｅ，ｆ及びｇは、各元素の原子比率を
示し、金属換算で、ｅ＝０．０１〜１０モル％、ｆ＝５
〜３０モル％、ｇ＝６５〜９５モル％、ｈは上記各成分
の原子価を満足するのに必要な酸素原子数である）で表
されることを特徴とする排気ガス浄化用触媒。3. A catalyst for purifying exhaust gases according to claim 1 or 2, wherein the zirconium oxide carrying platinum, the following general formula; [X] in e Ce f Zr g O h (wherein, X is At least one element selected from the group consisting of praseodymium, yttrium, lanthanum, and neodymium; e, f, and g each represent an atomic ratio of each element; e = 0.01 to 10 mol% in terms of metal; f = 5
-30 mol%, g = 65-95 mol%, and h is the number of oxygen atoms required to satisfy the valence of each of the above components).
ス浄化用触媒の触媒成分担持層中に、更にパラジウム担
持アルミナが含有され、該アルミナはセリウム、ジルコ
ニウム及びランタンからなる群より選ばれた少なくとも
一種を金属換算で１〜１０％含むことを特徴とする排気
ガス浄化用触媒。4. The catalyst component-supporting layer of the exhaust gas purifying catalyst according to claim 1, further comprising palladium-supported alumina, wherein the alumina is selected from the group consisting of cerium, zirconium, and lanthanum. An exhaust gas purifying catalyst comprising 1 to 10% of at least one of the above components in terms of metal.
ス浄化用触媒の触媒成分担持層中に、更にパラジウム担
持セリウム酸化物が含有され、該セリウム酸化物は、ジ
ルコニウム、ネオジウム及びランタンからなる群より選
ばれた一種を金属換算で１〜４０モル％含むことを特徴
とする排気ガス浄化用触媒。5. The exhaust gas purifying catalyst according to claim 1, further comprising a palladium-supported cerium oxide in the catalyst component-supporting layer, the cerium oxide comprising zirconium, neodymium, and lanthanum. An exhaust gas purifying catalyst comprising 1 to 40 mol% of one selected from the group consisting of:
媒において、ロジウム担持ジルコニウム酸化物を表層側
に、パラジウム担持触媒成分を内層側に配置して成るこ
とを特徴とする排気ガス浄化用触媒。6. The exhaust gas purifying catalyst according to claim 4, wherein a rhodium-supported zirconium oxide is disposed on a surface layer and a palladium-supported catalyst component is disposed on an inner layer side. catalyst.
ス浄化用触媒に、更に、アルカリ金属及びアルカリ土類
金属からなる群より選ばれた少なくとも一種が含有され
ることを特徴とする排気ガス浄化用触媒。7. The exhaust gas purifying catalyst according to claim 1, further comprising at least one selected from the group consisting of alkali metals and alkaline earth metals. Exhaust gas purification catalyst.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09376397A JP3988202B2 (en) | 1997-04-11 | 1997-04-11 | Exhaust gas purification catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09376397A JP3988202B2 (en) | 1997-04-11 | 1997-04-11 | Exhaust gas purification catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10286462A true JPH10286462A (en) | 1998-10-27 |
| JP3988202B2 JP3988202B2 (en) | 2007-10-10 |
Family
ID=14091479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP09376397A Expired - Fee Related JP3988202B2 (en) | 1997-04-11 | 1997-04-11 | Exhaust gas purification catalyst |
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| Country | Link |
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| JP (1) | JP3988202B2 (en) |
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| JP2001062295A (en) * | 1999-08-30 | 2001-03-13 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
| JP2001070792A (en) * | 1999-09-03 | 2001-03-21 | Daihatsu Motor Co Ltd | Catalyst for cleaning exhaust gas |
| JP2001079404A (en) * | 1999-09-14 | 2001-03-27 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
| JP2001079403A (en) * | 1999-09-14 | 2001-03-27 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
| JP2001104785A (en) * | 1999-10-08 | 2001-04-17 | Daihatsu Motor Co Ltd | Catalyst for purifying exhaust gas |
| JP2001104786A (en) * | 1999-10-08 | 2001-04-17 | Daihatsu Motor Co Ltd | Catalyst for purifying exhaust gas |
| JP2002011350A (en) * | 1999-05-24 | 2002-01-15 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
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| JP2003170047A (en) * | 2001-09-27 | 2003-06-17 | Tokyo Roki Co Ltd | Catalyst for cleaning exhaust gas and method for manufacturing the same |
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| JP2009090237A (en) * | 2007-10-10 | 2009-04-30 | Mazda Motor Corp | Catalyst material for purification of exhaust gas ingredient and particulate filter equipped with the catalyst material |
| JP2009106858A (en) * | 2007-10-30 | 2009-05-21 | Mazda Motor Corp | Catalyst material for cleaning exhaust gas component and particulate filter with the same catalyst material |
| JP2009526729A (en) * | 2006-02-17 | 2009-07-23 | ロデイア・オペラシヨン | Compositions based on oxides of zirconium, oxides of cerium, oxides of yttrium, oxides of lanthanum and other rare earths, methods for preparing the same and use as catalysts |
| US8153549B2 (en) | 2004-10-15 | 2012-04-10 | Johnson Matthey Public Limited Company | Catalyst for treating exhaust gas and device for treating exhaust gas using the same |
| JP2012518531A (en) * | 2009-02-20 | 2012-08-16 | ビー・エイ・エス・エフ、コーポレーション | Palladium supported catalyst composite |
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| JP2014200771A (en) * | 2013-04-09 | 2014-10-27 | トヨタ自動車株式会社 | Exhaust gas purification catalyst and exhaust gas cleaning method |
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|---|---|---|---|---|
| JP2002535135A (en) * | 1999-01-28 | 2002-10-22 | エンゲルハード・コーポレーシヨン | Catalyst composition containing oxygen storage component |
| JP2002011350A (en) * | 1999-05-24 | 2002-01-15 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
| JP2001062295A (en) * | 1999-08-30 | 2001-03-13 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
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| JP2001079403A (en) * | 1999-09-14 | 2001-03-27 | Daihatsu Motor Co Ltd | Exhaust gas cleaning catalyst |
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| JP2003170047A (en) * | 2001-09-27 | 2003-06-17 | Tokyo Roki Co Ltd | Catalyst for cleaning exhaust gas and method for manufacturing the same |
| US8153549B2 (en) | 2004-10-15 | 2012-04-10 | Johnson Matthey Public Limited Company | Catalyst for treating exhaust gas and device for treating exhaust gas using the same |
| JP2009526729A (en) * | 2006-02-17 | 2009-07-23 | ロデイア・オペラシヨン | Compositions based on oxides of zirconium, oxides of cerium, oxides of yttrium, oxides of lanthanum and other rare earths, methods for preparing the same and use as catalysts |
| JP2007275704A (en) * | 2006-04-03 | 2007-10-25 | Johnson Matthey Japan Inc | Exhaust gas catalyst and exhaust gas treating device using the same |
| WO2007116881A1 (en) * | 2006-04-03 | 2007-10-18 | Johnson Matthey Japan Incorporated | Exhaust gas catalyst and exhaust gas processing apparatus using the same |
| US8999252B2 (en) | 2006-04-03 | 2015-04-07 | Johnson Matthey Japan Incorporated | Exhaust gas catalyst and exhaust gas processing apparatus using same |
| JP2007301526A (en) * | 2006-05-15 | 2007-11-22 | Toyota Central Res & Dev Lab Inc | Catalyst for cleaning exhaust gas and its manufacturing method |
| WO2007132829A1 (en) * | 2006-05-15 | 2007-11-22 | Toyota Jidosha Kabushiki Kaisha | Catalyst for exhaust gas purification and method for producing the same |
| JP2009090238A (en) * | 2007-10-10 | 2009-04-30 | Mazda Motor Corp | Catalyst material for purification of exhaust gas ingredient and particulate filter equipped with the catalyst material |
| JP2009090237A (en) * | 2007-10-10 | 2009-04-30 | Mazda Motor Corp | Catalyst material for purification of exhaust gas ingredient and particulate filter equipped with the catalyst material |
| JP2009106858A (en) * | 2007-10-30 | 2009-05-21 | Mazda Motor Corp | Catalyst material for cleaning exhaust gas component and particulate filter with the same catalyst material |
| JP2012518531A (en) * | 2009-02-20 | 2012-08-16 | ビー・エイ・エス・エフ、コーポレーション | Palladium supported catalyst composite |
| JP2013059759A (en) * | 2011-08-22 | 2013-04-04 | Mazda Motor Corp | Catalyst for burning particulate matter |
| JP2014200771A (en) * | 2013-04-09 | 2014-10-27 | トヨタ自動車株式会社 | Exhaust gas purification catalyst and exhaust gas cleaning method |
| US9861959B2 (en) | 2013-04-09 | 2018-01-09 | Toyota Jidosha Kabushiki Kaisha | Catalyst composition and exhaust gas purifying method |
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