JP2000051700A - Exhaust emission purifying catalyst and its production - Google Patents
Exhaust emission purifying catalyst and its productionInfo
- Publication number
- JP2000051700A JP2000051700A JP10227275A JP22727598A JP2000051700A JP 2000051700 A JP2000051700 A JP 2000051700A JP 10227275 A JP10227275 A JP 10227275A JP 22727598 A JP22727598 A JP 22727598A JP 2000051700 A JP2000051700 A JP 2000051700A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- composite oxide
- perovskite
- alumina
- type composite
- 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.)
- Withdrawn
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 92
- 238000004519 manufacturing process Methods 0.000 title claims description 10
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 89
- 239000002131 composite material Substances 0.000 claims abstract description 62
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 59
- 239000007789 gas Substances 0.000 claims abstract description 47
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 44
- 229910052788 barium Inorganic materials 0.000 claims abstract description 9
- 229910052746 lanthanum Inorganic materials 0.000 claims abstract description 9
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 8
- 125000004430 oxygen atom Chemical group O* 0.000 claims abstract description 7
- 239000000843 powder Substances 0.000 claims description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 21
- 238000000746 purification Methods 0.000 claims description 15
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 10
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 10
- 229910052783 alkali metal Inorganic materials 0.000 claims description 9
- 150000001340 alkali metals Chemical class 0.000 claims description 9
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 8
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 8
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 8
- 239000001099 ammonium carbonate Substances 0.000 claims description 8
- 238000001354 calcination Methods 0.000 claims description 7
- 239000007864 aqueous solution Substances 0.000 claims description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 5
- 235000012501 ammonium carbonate Nutrition 0.000 claims description 5
- 239000000084 colloidal system Substances 0.000 claims description 5
- 238000001035 drying Methods 0.000 claims description 5
- 239000010419 fine particle Substances 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims description 4
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 claims description 3
- 235000012538 ammonium bicarbonate Nutrition 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 20
- 238000000034 method Methods 0.000 description 29
- 238000002360 preparation method Methods 0.000 description 27
- 239000000243 solution Substances 0.000 description 22
- 230000000052 comparative effect Effects 0.000 description 21
- 229910000510 noble metal Inorganic materials 0.000 description 14
- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 13
- 239000000203 mixture Substances 0.000 description 12
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 11
- 239000010410 layer Substances 0.000 description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 9
- 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 9
- 239000000463 material Substances 0.000 description 9
- 239000001301 oxygen Substances 0.000 description 9
- 229910052760 oxygen Inorganic materials 0.000 description 9
- 239000011247 coating layer Substances 0.000 description 8
- 150000001875 compounds Chemical class 0.000 description 8
- 238000001556 precipitation Methods 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 238000005245 sintering Methods 0.000 description 7
- 239000007921 spray Substances 0.000 description 7
- 230000003197 catalytic effect Effects 0.000 description 6
- 238000003756 stirring Methods 0.000 description 6
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 238000005470 impregnation Methods 0.000 description 5
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000001737 promoting effect Effects 0.000 description 5
- 238000010298 pulverizing process Methods 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- 230000004913 activation Effects 0.000 description 4
- 238000009835 boiling Methods 0.000 description 4
- ZMIGMASIKSOYAM-UHFFFAOYSA-N cerium Chemical compound [Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce][Ce] ZMIGMASIKSOYAM-UHFFFAOYSA-N 0.000 description 4
- 239000000470 constituent Substances 0.000 description 4
- 229910052878 cordierite Inorganic materials 0.000 description 4
- 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 4
- 238000010304 firing Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 3
- 150000001341 alkaline earth metal compounds Chemical class 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 230000008020 evaporation Effects 0.000 description 3
- -1 inorganic acid salts Chemical class 0.000 description 3
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 239000010970 precious metal Substances 0.000 description 3
- 150000003839 salts Chemical class 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
- 239000000725 suspension Substances 0.000 description 3
- 229910052726 zirconium Inorganic materials 0.000 description 3
- 101100321669 Fagopyrum esculentum FA02 gene Proteins 0.000 description 2
- 229910052779 Neodymium Inorganic materials 0.000 description 2
- 229910052772 Samarium Inorganic materials 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 150000001242 acetic acid derivatives Chemical class 0.000 description 2
- 150000001339 alkali metal compounds Chemical class 0.000 description 2
- 150000003868 ammonium compounds Chemical class 0.000 description 2
- IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Chemical compound [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 229910052735 hafnium Inorganic materials 0.000 description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 238000005342 ion exchange Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000007769 metal material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 2
- 150000002823 nitrates Chemical class 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 2
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 102000004190 Enzymes Human genes 0.000 description 1
- 108090000790 Enzymes Proteins 0.000 description 1
- 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 1
- 229910021193 La 2 O 3 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
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 150000003863 ammonium salts Chemical class 0.000 description 1
- 229910052792 caesium Inorganic materials 0.000 description 1
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 235000015165 citric acid Nutrition 0.000 description 1
- 150000001860 citric acid derivatives Chemical class 0.000 description 1
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid group Chemical class C(CC(O)(C(=O)O)CC(=O)O)(=O)O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 150000003840 hydrochlorides Chemical class 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 150000002941 palladium compounds Chemical class 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 238000003746 solid phase reaction Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000004065 wastewater treatment Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
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
媒及びその製造方法に関し、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 」と杯す）を低温においても
有効に浄化することができる、低温活性に優れ、全ての
排気ガス組成雰囲気下において触媒活性に優れる排気ガ
ス浄化用触媒及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying catalyst and a method for producing the same, and more particularly to a hydrocarbon (hereinafter referred to as "HC") in exhaust gas discharged from an internal combustion engine such as an automobile.
), Carbon monoxide (hereinafter referred to as “CO”) and nitrogen oxides (hereinafter referred to as “NO x ”) can be effectively purified even at a low temperature. The present invention relates to an exhaust gas purifying catalyst having excellent catalytic activity under an atmosphere of exhaust gas composition and a method for producing the same.
【０００２】[0002]
【従来の技術】従来より、内燃機関始動直後から触媒温
度が排気ガス浄化用反応温度に達するまでの低温期間
は、排気ガスの浄化能が十分でないため、低温から排気
ガス浄化反応を開始す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, during a low temperature period from the start of an internal combustion engine until the catalyst temperature reaches a reaction temperature for exhaust gas purification, the exhaust gas purification performance is not sufficient. The development of gas purification catalysts is expected.
【０００３】かかる排気ガス浄化用触媒としては、例え
ば、特開平５−３０５２３６号公報に、貴金属を含まな
いヘキサアルミネートを白金、ロジウム、パラジウム等
の貴金属担持アルミナに混成分散させた排気ガス浄化触
媒が開示されており、具体的には一定の組成を有するヘ
キサアルミネート組成物と白金、ロジウム、パラジウム
から成る群から選ばれた少なくとも一種の貴金属を担持
したアルミナを一定の重量比で混成した触媒である。As such an exhaust gas purifying catalyst, for example, Japanese Patent Laid-Open Publication No. 5-305236 discloses an exhaust gas purifying catalyst in which hexaaluminate containing no noble metal is mixed and dispersed in a noble metal-supported alumina such as platinum, rhodium and palladium. Specifically, a catalyst in which a hexaaluminate composition having a certain composition and alumina supporting at least one noble metal selected from the group consisting of platinum, rhodium and palladium are mixed at a certain weight ratio It is.
【０００４】また、特開平８−３２３２０５号公報に
は、触媒成分として少なくともパラジウムと金属アルミ
ネートとを含有する排気ガス浄化用触媒が提案されてい
る。[0004] Japanese Patent Application Laid-Open No. 8-323205 proposes an exhaust gas purifying catalyst containing at least palladium and metal aluminate as catalyst components.
【０００５】[0005]
【発明が解決しようとする課題】しかし、前記広報中に
記載された従来の触媒は、初期から耐久後まで高い浄化
性能を維持するため、貴金属を多量に使用している。こ
のため、排気ガス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。ところが、貴金属量を低減した場
合、高温下における耐久性が不十分で、耐久後は低温域
での触媒活性や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 publication uses a large amount of a noble metal in order to maintain high purification performance from the initial stage to after the endurance. For this reason, as a three-way catalyst for purifying exhaust gas, a catalyst that can obtain high purification performance even when the amount of noble metal used is small is desired. However, when the amount of the noble metal is reduced, there is a problem that the durability at high temperatures is insufficient, and after the durability, the catalytic activity and purification performance in a low temperature region are deteriorated.
【０００６】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、
上記の影響が顕著に現れ、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 a stoichiometric air-fuel ratio (hereinafter referred to as "stoichiometric"), and a reducing atmosphere (hereinafter, referred to as "stoichiometric") having an insufficient oxygen concentration.
Under the exhaust gas atmosphere of automobiles whose composition changes widely from an oxidizing atmosphere (hereinafter referred to as "lean") to an oxidizing atmosphere having an excessively high oxygen concentration (hereinafter referred to as "lean"), deterioration (sintering) of noble metal species is promoted As a result, it is considered that the purification performance is reduced. In particular, when reducing the amount of precious metals,
There has been a problem that the above-mentioned effects appear remarkably and the purification performance is further reduced.
【０００７】従って、本発明の目的は、従来の触媒より
も耐久性が向上し、幅広い排気ガス組成雰囲気下で、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
ガス浄化用触媒及びその製造方法を提供することにあ
る。Accordingly, an object of the present invention is to provide an exhaust gas purifying catalyst which has improved durability over conventional catalysts and has excellent low-temperature activity and purifying performance even after endurance under a wide range of exhaust gas composition atmospheres. It is to provide a manufacturing method.
【０００８】[0008]
【課題を解決するための手投】本発明者らは、上記課題
を解決するために鋭意研究した結果、特定のペロブスカ
イト型複合酸化物と、アルミナと、パラジウムとを含
み、特に一定の組成比率でランタン、セリウム及びバリ
ウムからなる群より選ばれた少なくとも１種とニッケル
とを含有したペロブスカイト型複合酸化物をアルミナ上
に高分散させた材料を貴金属担持基材として用いること
により、貴金属の活性化が促進され、初期から耐久後ま
で低温活性を向上させ、且つ、ストイキ域を中心に酸素
濃度が不十分なリッチ域においてもＨＣ，ＣＯ，ＮＯx
の浄化率が向上することを見出し、本発明を完成した。The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, the present inventors have found that a specific perovskite-type composite oxide, alumina, and palladium are contained, and a specific composition ratio is particularly high. Activation of a noble metal by using a material in which a perovskite-type composite oxide containing at least one selected from the group consisting of lanthanum, cerium and barium and nickel is highly dispersed on alumina as a noble metal-supporting substrate Is promoted, the low-temperature activity is improved from the initial stage to after the endurance, and HC, CO, and NO x are obtained even in the rich region where the oxygen concentration is insufficient, mainly in the stoichiometric region.
The present inventors have found that the purification rate of methane is improved, and completed the present invention.
【０００９】また、このペロブスカイト型複合酸化物が
分散したアルミナを、特定の製造方法で調整し、特に、
当該ペロブスカイト型複合酸化物が分散したアルミナに
貴金属を担持することで、高温での構造安定性に優れ、
かつ、上記貴金属の活性化促進作用にも優れることを見
出し、本発明に到達した。The alumina in which the perovskite-type composite oxide is dispersed is prepared by a specific production method.
By supporting the noble metal on alumina in which the perovskite-type composite oxide is dispersed, excellent structural stability at high temperatures,
In addition, they have found that the noble metal is also excellent in promoting the activation, and arrived at the present invention.
【００１０】即ち、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であって、
触媒成分として次の一般式； Ａx Ｎｉy Ｏz （式中、ＡはＬａ、Ｃｅ及びＢａからなる群より選ばれ
た少なくとも一種の元素であり、ｘ，ｙ及びｚは各元素
の原子比率を示し、ｙ＝１．０の時、ｘ＝０．０１以上
０．１未満、ｚ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）で表されるペロブスカイト型複
合酸化物と、アルミナと、パラジウムとを含むことを特
徴とする。That is, the exhaust gas purifying catalyst according to claim 1 is an integrated catalyst having a catalyst component supporting layer,
A x Ni y O z (where A is at least one element selected from the group consisting of La, Ce and Ba, and x, y and z are atomic ratios of each element as a catalyst component) Where y = 1.0, x = 0.01 or more and less than 0.1, and z is the number of oxygen atoms necessary to satisfy the valence of each component described above.) It is characterized by containing an oxide, alumina, and palladium.
【００１１】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において、上記ペロブ
スカイト型複合酸化物がアルミナ上に高分散し、かつ、
上記ペロブスカイト型複合酸化物とアルミナとの混合比
が、ペロブスカイト型複合酸化物中のＮｉとアルミナ中
のＡｌがモル比でＮｉ／Ａｌ＝０．１５〜１．０である
ことを特徴とする。According to a second aspect of the present invention, in the exhaust gas purifying catalyst according to the first aspect, the perovskite-type composite oxide is highly dispersed on alumina, and
The mixing ratio between the perovskite-type composite oxide and alumina is such that the molar ratio of Ni in the perovskite-type composite oxide to Al in alumina is Ni / Al = 0.15 to 1.0.
【００１２】請求項３記載の排気ガス浄化用触媒は、請
求項２記載の排気ガス浄化用触媒において、ペロブスカ
イト型複合酸化物が高分散したアルミナに、パラジウム
が担持されて成ることを特徴とする。According to a third aspect of the present invention, there is provided an exhaust gas purifying catalyst according to the second aspect, wherein palladium is supported on alumina in which a perovskite-type composite oxide is highly dispersed. .
【００１３】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、
更にアルカリ金属およびアルカリ土類金属から成る群よ
り選ばれる１種が含有されることを特徴とする。[0013] The exhaust gas purifying catalyst according to claim 4 is the same as the exhaust gas purifying catalyst according to any one of claims 1 to 3,
Further, one kind selected from the group consisting of an alkali metal and an alkaline earth metal is contained.
【００１４】請求項５記載の排気ガス浄化用触媒を製造
する方法は、請求項１〜３いずれかの項記載の排気ガス
用触媒を製造するにあたり、請求項１〜３いずれかの項
に記載のペロブスカイト型複合酸化物と、微粒子アルミ
ナ水和物コロイドとを水に分散させた後、水分を除去し
て乾燥し、焼成し、得られたペロブスカイト型複合酸化
物が分散したアルミナ粉末に、パラジウムを担持するこ
とを特徴とする。According to a fifth aspect of the present invention, there is provided a method for producing an exhaust gas purifying catalyst according to any one of the first to third aspects. After dispersing perovskite-type composite oxide and fine-particle alumina hydrate colloid in water, removing water, drying and calcining, the obtained alumina powder in which the perovskite-type composite oxide is dispersed, palladium Is carried.
【００１５】請求項６記載の排気ガス浄化用触媒の製造
方法は、請求項１〜３いずれかの項記載の排気ガス浄化
用触媒を製造するにあたり、請求項１〜３いずれかの項
記載のペロブスカイト型複合酸化物と、微粒子アルミナ
水和物コロイドとを水に分散させた後、アンモニア水、
炭酸アンモニウム及び炭酸水素アンモニウムから成る群
より選ばれた少なくとも一種の水溶液を加え、ＰＨを
７．０〜９．０の範囲になるように調整した後、水分を
除去して乾燥し、焼成し、得られたペロブスカイト型複
合酸化物が分散したアルミナ粉末に、パラジウムを担持
することを特徴とする。According to a sixth aspect of the present invention, there is provided a method for producing an exhaust gas purifying catalyst according to any one of the first to third aspects. After dispersing perovskite-type composite oxide and fine-particle alumina hydrate colloid in water, ammonia water,
At least one aqueous solution selected from the group consisting of ammonium carbonate and ammonium bicarbonate is added, and the pH is adjusted to be in a range of 7.0 to 9.0. Then, moisture is removed, dried, and calcined. Palladium is supported on the alumina powder in which the obtained perovskite-type composite oxide is dispersed.
【００１６】[0016]
【発明の実施の形態】本発明の排気ガス浄化触媒の高温
下の構造安定性及び表面積を高めるために、触媒成分担
持層には、次の一般式 Ａx Ｎｉy Ｏz （式中、ＡはＬａ、Ｃｅ及びＢａからなる群より選ばれ
た少なくとも一種の元素であり、ｘ，ｙ及びｚは各元素
の原子比率を示し、ｙ＝１．０の時、ｘ＝０．０１以上
０．１未満、ｚ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）で表されるペロブスカイト型複
合酸化物が含有される。BEST MODE FOR CARRYING OUT THE INVENTION In order to increase the structural stability and surface area of an exhaust gas purifying catalyst of the present invention at high temperatures, the catalyst component supporting layer has the following general formula A x Ni y O z (where A is Is at least one element selected from the group consisting of La, Ce and Ba, x, y and z indicate the atomic ratio of each element, and when y = 1.0, x = 0.01 or more. Is less than 1, and z is the number of oxygen atoms necessary to satisfy the valence of each of the above components).
【００１７】上記ペロブスカイト型複合酸化物におい
て、ｙ＝１．０の時、ｘ＝０．０１未満では、ランタ
ン、セリウム、バリウム元素による貴金属のシンタリン
グ抑制という作用が小さく充分な改良効果が得られず、
ニッケルをアルミナに含浸担持して得た粉末とパラジウ
ムとからなる触媒と何ら変わらない。In the above perovskite-type composite oxide, when y = 1.0 and x is less than 0.01, the effect of suppressing sintering of noble metals by lanthanum, cerium and barium elements is small, and a sufficient improvement effect can be obtained. Without
It is no different from a catalyst composed of powder obtained by impregnating and supporting nickel on alumina and palladium.
【００１８】また、ｘ＝０．１を越えると、アルミナに
ペロブスカイト型複合酸化物を分散して得られる粉末の
ＢＥＴ比表面積や熱安定性等の物性が低下するため、貴
金属の分散性が悪く、初期において充分な性能が得られ
なかったり、耐久中に貴金属のシンタリングを助長し、
逆に耐久後の性能が悪化する。On the other hand, if x exceeds 0.1, physical properties such as BET specific surface area and thermal stability of a powder obtained by dispersing a perovskite-type composite oxide in alumina are deteriorated. , Sufficient performance can not be obtained in the early stage, or sintering of precious metal during durability,
Conversely, the performance after durability deteriorates.
【００１９】このように、特定の組成比のペロブスカイ
ト型複合酸化物とすることにより、耐久中の貴金属のシ
ンタリングが抑制され、耐久後の性能が向上し、かつ、
酸化物中の格子酸素や吸着酸素が移動・放出されやすく
なり、低温活性等の触媒性能を向上させることとなる。As described above, by using a perovskite-type composite oxide having a specific composition ratio, sintering of a noble metal during durability is suppressed, performance after durability is improved, and
The lattice oxygen and the adsorbed oxygen in the oxide are easily transferred and released, and the catalytic performance such as low-temperature activity is improved.
【００２０】更に、上記ペロブスカイト型複合酸化物が
アルミナ上に高分散し、かつその混合比が、ペロブスカ
イト型複合酸化物中のＮｉとアルミナ中のＡｌがモル比
でＮｉ／Ａｌ＝０．１５から１．０であることが好まし
い。Further, the above-mentioned perovskite-type composite oxide is highly dispersed on alumina, and the mixing ratio thereof is such that the molar ratio of Ni in the perovskite-type composite oxide to Al in alumina is Ni / Al = 0.15. It is preferably 1.0.
【００２１】このように、ペロブスカイト型複合酸化物
がアルミナ上に高分散被覆されることにより、ペロブス
カイト型複合酸化物の分散性が向上するため、パラジウ
ムとペロブスカイト型複合酸化物の接触が密となる。よ
って、酸化物中の格子酵素や吸着酸素が移動・放出され
やすくなり、低温活性等の触媒性能を向上させることと
なる。また、ペロブスカイト型複合酸化物とパラジウム
の触媒が密となることで、耐久性も向上する。As described above, since the perovskite-type composite oxide is highly dispersed and coated on the alumina, the dispersibility of the perovskite-type composite oxide is improved, so that the contact between the palladium and the perovskite-type composite oxide is increased. . Therefore, the lattice enzyme and the adsorbed oxygen in the oxide are easily transferred and released, and the catalytic performance such as low-temperature activity is improved. In addition, since the perovskite-type composite oxide and the palladium catalyst are dense, the durability is also improved.
【００２２】Ｎｉ／Ａｌが０．１５未満ではペロブスカ
イト型複合酸化物の上記効果が得られず、アルミナにパ
ラジウムを担持したものと変わらない。また、Ｎｉ／Ａ
ｌ比が１．０を越えると、アルミナにペロブスカイト型
複合酸化物を分散して得られる粉末のＢＥＴ比表面積や
熱安定性等の物性が低下するため、貴金属の分散性が悪
く、初期において充分な性能が得られなかったり、耐久
中に貴金属のシンタリングを助成し、逆に耐久後の性能
が悪化する。If Ni / Al is less than 0.15, the above-mentioned effect of the perovskite-type composite oxide cannot be obtained, which is the same as that obtained by supporting palladium on alumina. Also, Ni / A
When the l ratio exceeds 1.0, physical properties such as BET specific surface area and thermal stability of a powder obtained by dispersing a perovskite-type composite oxide in alumina are deteriorated. Performance cannot be obtained, or sintering of precious metals is promoted during durability, and conversely, performance after durability deteriorates.
【００２３】該複合化合物の各構成元素は、触媒に含ま
れるこれらの全てが複合化している場合にその上記した
作用は最大限に発揮されるが、少なくとも一部が複合体
を形成しうる場合でも十分に上記作用を得ることができ
る。Each of the constituent elements of the composite compound exerts the above-mentioned effects to the maximum when all of them contained in the catalyst are complexed, but when at least a part thereof can form a complex. However, the above effect can be sufficiently obtained.
【００２４】該複合化合物の各構成元素は、熱耐久後で
の別々の酸化物として分離することではなく複合酸化物
として存在することができ、これは例えばＸ線回折測定
により確認することができる。Each constituent element of the composite compound can exist as a composite oxide instead of being separated as a separate oxide after heat endurance, which can be confirmed by, for example, X-ray diffraction measurement. .
【００２５】該複合化合物の各構成元素には、その上記
作用を妨げる量でなければ微量の不純物を含んでも構わ
ず、例えば、バリウム中に含まれるストロンチウムやラ
ンタン中に含まれるセリウム、ネオジウム、サマリウム
や、ジルコニウム中に含まれるハフニウムやイオウ等で
ある。Each of the constituent elements of the composite compound may contain a trace amount of impurities as long as it does not interfere with the above action. For example, strontium contained in barium and cerium, neodymium, samarium contained in lanthanum. And hafnium and sulfur contained in zirconium.
【００２６】更に好ましくは、前記ペロブスカイト型複
合酸化物が高分散したアルミナにパラジウムを担持す
る。このようにすると、パラジウムが、ペロブスカイト
型複合酸化物と密に接触することができ、酸化物中の格
子酸素や表面の吸着酸素が移動・放出され易くなり、低
温活性と酸素雰囲気での浄化性能等の触媒性能を向上さ
せることとなる。More preferably, palladium is carried on alumina in which the perovskite-type composite oxide is highly dispersed. In this way, palladium can come into close contact with the perovskite-type composite oxide, which facilitates the movement and release of lattice oxygen in the oxide and adsorbed oxygen on the surface, resulting in low-temperature activity and purification performance in an oxygen atmosphere. And the like.
【００２７】当該パラジウムの含有量は、触媒１Ｌ容量
中０．０１〜１０ｇ／Ｌである。０．０１ｇ未満では低
温活性や浄化性能が充分に発揮されず、逆に１０ｇを越
えてもパラジウムの分散性が悪くなり、触媒性能は顕著
に向上せず、経済的にも有効でない。The content of the palladium is 0.01 to 10 g / L in 1 L of the catalyst. If the amount is less than 0.01 g, the low-temperature activity and the purification performance are not sufficiently exhibited. Conversely, if the amount exceeds 10 g, the dispersibility of palladium deteriorates, the catalyst performance is not significantly improved, and it is not economically effective.
【００２８】上記ペロブスカイト型複合酸化物を担持す
るための基材には、ペロブスカイト型複合酸化物の分散
性、また耐久後のパラジウムの分散性を確保するため、
比表面積の大きい耐熱性無機材料が適し、特にアルミ
ナ、好ましくは活性アルミナが望ましい。耐熱比表面積
を高めるために希土類元素やジルコニヤ等を添加したア
ルミナを使用してもよい。In order to ensure the dispersibility of the perovskite-type composite oxide and the palladium after endurance, the base material for supporting the perovskite-type composite oxide is
A heat-resistant inorganic material having a large specific surface area is suitable, and alumina, particularly activated alumina is desirable. Alumina to which a rare earth element, zirconia, or the like is added to increase the heat resistant specific surface area may be used.
【００２９】本発明に用いるペロブスカイト型複合酸化
物は、複合酸化物の各構成元素の硝酸塩、酢酸塩、炭酸
塩、クエン酸、塩酸塩等を、所望する複合酸化物の組成
比に混合し、仮焼成した後粉砕して、熱処理焼成する固
相反応や、複合酸化物の各構成要素の硝酸塩、酢酸塩、
炭酸塩、クエン酸塩等を、所望する複合酸化物の組成比
に混合し、水に溶解した後、必要に応じてＮＨ4 ＯＨや
ＮＨ3 ＣＯ3 等のアルカリ溶液を滴下して沈殿物を生成
し、ろ過した後沈殿物を乾燥させて焼成する共沈法によ
り調整することができ、これにより、均一な組成比の結
晶構造が得られえる。しかし、これらの方法に限定され
るものではなく、前記以外の方法でも複合酸化物が形成
されるものであればよい。The perovskite-type composite oxide used in the present invention is obtained by mixing nitrates, acetates, carbonates, citric acids, hydrochlorides, etc. of the respective constituent elements of the composite oxide in a desired composition ratio of the composite oxide. After calcination, pulverization, solid-phase reaction of heat treatment and calcination, nitrate, acetate,
Carbonates, citrates and the like are mixed in a desired composite oxide composition ratio and dissolved in water.If necessary, an alkaline solution such as NH 4 OH or NH 3 CO 3 is added dropwise to precipitate the solution. It can be adjusted by a coprecipitation method in which the precipitate is formed, filtered, dried and calcined, whereby a crystal structure having a uniform composition ratio can be obtained. However, the method is not limited to these methods, and any method other than the above may be used as long as the composite oxide is formed.
【００３０】かかる方法により、複合酸化物を構成する
各部分の少なくとも一部を複合化することができる。According to such a method, at least a part of each part constituting the composite oxide can be composited.
【００３１】本発明で用いる複合酸化物の触媒調製用原
料には、前記したように、その上記作用を妨げる量でな
ければ微量の不純物を含んでも構わず、例えばバリウム
中に含まれるストロンチウムやランタン中に含まれるセ
リウム、ネオジウム、サマリウムやジルコニウム中に含
まれるハフニウムやイオウ等である。As described above, the raw material for preparing the catalyst of the composite oxide used in the present invention may contain a trace amount of impurities as long as the amount does not interfere with the above-mentioned effects. For example, strontium and lanthanum contained in barium may be contained. Cerium, neodymium, samarium and hafnium and sulfur contained in zirconium contained therein.
【００３２】このようにして得たペロブスカイト型複合
酸化物と、微粒子アルミナ水和物コロラド（以下、「ア
ルミナゾル」と示す）とを水に分解させた後、水分を除
去して残留物を乾燥し、焼成して、ペロブスカイト型複
合酸化物が分散したアルミナ粉末を得ることができる。After the perovskite-type composite oxide thus obtained and fine-particle alumina hydrate Colorado (hereinafter referred to as “alumina sol”) are decomposed into water, the water is removed and the residue is dried. After firing, an alumina powder in which the perovskite-type composite oxide is dispersed can be obtained.
【００３３】アルミナゾルをアルミニウム原料化合物と
して用いることで、アルミニウムの水溶性塩で調製した
ものに比べ、結晶構造の均一性と耐熱性を更に向上させ
ることができ、ペロブスカイト型複合酸化を高分散担持
するための比表面積が十分に確保できる。従って、パラ
ジウムと活性相とが更に密に接触することができるた
め、パラジウムの活性化促進作用が増大し、排気ガス浄
化用触媒の低温活性と浄化性能等の触媒性能を向上させ
ることとなる。By using alumina sol as the aluminum raw material compound, the uniformity of the crystal structure and the heat resistance can be further improved as compared with those prepared using a water-soluble salt of aluminum, and the perovskite-type composite oxide is highly dispersed and supported. Specific surface area can be sufficiently secured. Therefore, the palladium and the active phase can be brought into more intimate contact with each other, so that the activation promoting action of the palladium is increased, and the low-temperature activity and purification performance of the exhaust gas purification catalyst are improved.
【００３４】また、ペロブスカイト型複合酸化物が分散
したアルミナ粉末を得る他の方法は、ペロブスカイト型
複合酸化物とアルミナゾルとを水に分散させたに後、沈
殿剤としてアンモニア水、炭酸アンモニウム及び炭酸ア
ンモニアからなる群より選ばれた少なくとも一種の水溶
液を徐々に加え、ｐＨを７．０〜９．０の範囲になるよ
うに調製した後、水分を除去して残留物を乾燥し、次い
で焼成して得る方法がある。Another method for obtaining an alumina powder in which a perovskite-type composite oxide is dispersed is to disperse a perovskite-type composite oxide and an alumina sol in water, and then use ammonia water, ammonium carbonate and ammonium carbonate as precipitants. After gradually adding at least one aqueous solution selected from the group consisting of and adjusting the pH to be in the range of 7.0 to 9.0, the water is removed, the residue is dried, and then calcined. There is a way to get it.
【００３５】上記アルミナゾルをアルミニウム原料化合
物として用い、更に上述したような沈殿法により製造す
ることで、アルミナが有する微細な細孔構造と大きな比
表面が得られ、更にペロブスカイト型複合酸化物の活性
相の均一な分散状態が得られ、これによりパラジウムの
活性化促進作用が有効に発現できる。By using the above-mentioned alumina sol as an aluminum raw material compound and producing it by the above-described precipitation method, a fine pore structure and a large specific surface of alumina can be obtained, and the active phase of perovskite-type composite oxide can be obtained. Is obtained, whereby the activation promoting action of palladium can be effectively exhibited.
【００３６】また、アルミナゾルは、コロイドを５μｍ
〜２００μｍの大きさを有する安定なコロイド状態とす
るため、ｐＨを２．０〜７．０に調製したアルミナゾル
を使用することが、結晶構造の均一性や耐熱性を向上
し、パラジウムの活性化の促進作用を向上する点から好
ましい。The alumina sol has a colloid of 5 μm
Use of an alumina sol whose pH is adjusted to 2.0 to 7.0 in order to obtain a stable colloidal state having a size of about 200 μm improves the uniformity of the crystal structure and heat resistance, and activates palladium. It is preferable from the viewpoint of improving the action of promoting the action.
【００３７】前記ペロブスカイト型複合酸化物が分散し
たアルミナ粉末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、公知の蒸発乾
固法、沈殿法、含浸法等の種々の方法の中から適宜選択
して使用することができるが、上記各元素の原料を水に
分散させた後、特に、アンモニア水、炭酸アンモニウム
及び炭酸水素アンモニウムからなる群より選ばれた少な
くとも一種の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、アルミナ系複合酸化物の充分なＢＥ
Ｔ比表面積と結晶構造の均一性を確保し、ペロブスカイ
ト型複合酸化物やパラジウムを均一に分散するために好
ましい。The method for preparing the alumina powder in which the perovskite-type composite oxide is dispersed is not limited to a special method, and may be any of known methods such as evaporation to dryness, precipitation, impregnation, and the like, unless the components are significantly unevenly distributed. It can be appropriately selected from various methods and used, but after dispersing the raw material of each of the above elements in water, in particular, ammonia water, at least one selected from the group consisting of ammonium carbonate and ammonium hydrogen carbonate The use of a precipitation method in which an aqueous solution of the compound of formula (1) is added as a precipitant makes it possible to obtain a sufficient BE of the alumina-based composite oxide.
It is preferable to ensure uniformity of the T specific surface area and the crystal structure, and to uniformly disperse the perovskite-type composite oxide and palladium.
【００３８】前記沈殿法に用いる沈殿剤として、上記ア
ンモニア水やアンモニウム化合物を使用すれば、沈殿ケ
ーキの清浄が不十分でも金属元素は残留せず、またアン
モウム化合物（滴下後は、主として硝酸アンモニウム）
が残留しても後の焼成で容易に分解除去することができ
る。更に、硝酸アンモニウムに代わりアルミナゾルを使
用するため、沈殿を乾燥・焼成する際に、原料由来のＮ
ＯX や硝酸アンモニウムに対する排ガス・排水処理が著
しく軽減される。If the above-mentioned aqueous ammonia or ammonium compound is used as a precipitant for the precipitation method, no metal element remains even if the precipitation cake is insufficiently cleaned, and an ammonium compound (mainly ammonium nitrate after dropping) is used.
Can be easily decomposed and removed in the subsequent firing. Furthermore, since alumina sol is used in place of ammonium nitrate, when drying and firing the precipitate, N
Exhaust gas or waste water treatment for the O X or ammonium nitrate is significantly reduced.
【００３９】上記沈殿法を実施する際しては、溶液のｐ
Ｈを７．０〜９．０の範囲に調製することにより、各種
金属塩の沈殿物を形成することができる。ｐＨは７．０
より低いと充分に沈殿物を形成せず、逆にｐＨが９．０
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 above precipitation method, the p
By adjusting H in the range of 7.0 to 9.0, precipitates of various metal salts can be formed. pH is 7.0
If it is lower, a precipitate does not sufficiently form, and conversely, the pH is 9.0
If it is higher, some of the precipitated components may be redissolved.
【００４０】水の除去は、例えば濾過法や蒸発乾固法や
スプレードライ法等の公知の方法の中から適宜選択して
行なうことができる。本発明では、特に制限されない
が、パラジウムの分散性を向上するための大きな比表面
積を得るため、スプレードライヤーで行なうことが望ま
しい。ペロブスカイト型複合酸化物が分散したアルミナ
を得るための最初の熱処理は、特に制限されないが、例
えば７００〜１２００℃の温度範囲で空気及び／又は空
気流通下で行なうことが好ましい。The removal of water can be appropriately selected from known methods such as a filtration method, an evaporation to dryness method and a spray drying method. In the present invention, although not particularly limited, it is desirable to use a spray dryer in order to obtain a large specific surface area for improving the dispersibility of palladium. The first heat treatment for obtaining alumina in which the perovskite-type composite oxide is dispersed is not particularly limited, but is preferably performed, for example, in a temperature range of 700 to 1200 ° C. under air and / or air flow.
【００４１】本発明に用いるパラジウムの原料化合物と
しては、無機酸塩、炭酸塩、アンモニム塩、有機酸塩、
ハロゲン化物、酸化物、ナトリウム塩、アンミン錯化合
物等を組み合わせて使用することができるが、特に水溶
性の塩を使用することが触媒性能を向上させる観点から
好ましい。パラジウムの担持法としては特殊な方法に限
定されず、成分の著しい偏在を伴わない限り、公知の蒸
発乾固法、沈殿法、含浸法、イオン交換等の種々の方法
を用いることができる。特にアルミナへの担持には、分
散性を高める点から含浸法が好ましい。The starting palladium compounds used in the present invention include inorganic acid salts, carbonates, ammonium salts, organic acid salts,
Although halides, oxides, sodium salts, ammine complex compounds and the like can be used in combination, it is particularly preferable to use water-soluble salts from the viewpoint of improving the catalyst performance. The method for supporting palladium is not limited to a special method, and various methods such as a well-known evaporation and drying method, a precipitation method, an impregnation method, and an ion exchange method can be used as long as there is no significant uneven distribution of components. In particular, the impregnation method is preferable for supporting on alumina, from the viewpoint of increasing dispersibility.
【００４２】イオン交換法、含浸法による場合、金属原
料は容液で用いることが多いため、その溶液に酸あるい
は塩基を添加して、ｐＨを調節することもできる。ｐＨ
を調節することにより、更に、高分散担持できる可能性
もある。In the case of the ion exchange method or the impregnation method, since the metal raw material is often used in a solution, the pH can be adjusted by adding an acid or a base to the solution. pH
By adjusting the value, it is possible that the particles can be further highly dispersed and supported.
【００４３】本発明のパラジウムを担持した、ペロブス
カイト型複合酸化物を分散したアルミナの熱処理は、特
に制限されないが、含浸・乾燥後、例えば４００℃〜７
００℃の範囲の温度で空気中及び／又は空気気流下で行
なうことが好ましい。The heat treatment of the alumina in which the perovskite-type composite oxide carrying palladium of the present invention is dispersed is not particularly limited, but after impregnation and drying, for example, at 400 ° C. to 7 ° C.
It is preferable to carry out at a temperature in the range of 00 ° C. in the air and / or under an air stream.
【００４４】本発明の触媒は、一体構造型担体に担持し
て用いるのが好ましく、複合酸化物及び貴金属担持無機
担体を粉砕してスラリーとし、触媒担体にコートして、
４００〜９００℃の温度で焼成することにより、本発明
の排気ガス浄化用触媒を得ることができる。The catalyst of the present invention is preferably used by being supported on a monolithic carrier. The composite oxide and the noble metal-supported inorganic carrier are pulverized into a slurry, and the slurry is coated on the catalyst carrier.
By firing at a temperature of 400 to 900 ° C., the exhaust gas purifying catalyst of the present invention can be obtained.
【００４５】複合酸化物及び貴金属担持無機担体を粉砕
するにあたっての粉砕方法は特に限定されず、好ましく
はこれらを含む水性スラリーを湿式粉砕して、平均粒経
が４μｍ以下になるように調製する方法を用いことがで
きる。The pulverization method for pulverizing the composite oxide and the noble metal-carrying inorganic carrier is not particularly limited. Preferably, an aqueous slurry containing these is wet-pulverized to adjust the average particle size to 4 μm or less. Can be used.
【００４６】粉砕に使用することのできる装置が特に限
定されず、市販のボール式振動ミルを用いることがで
き、ボール径、粉砕時間、振幅、振動周波数を調製して
所望の粒径を得る。The apparatus that can be used for pulverization is not particularly limited, and a commercially available ball-type vibrating mill can be used. The ball diameter, the pulverizing time, the amplitude, and the vibration frequency are adjusted to obtain a desired particle size.
【００４７】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
からなるモノリス構造を有するハニカム担体やメタル担
体等が挙げられる。The catalyst carrier can be appropriately selected from known catalyst carriers, and includes, for example, a honeycomb carrier and a metal carrier having a monolith structure made of a refractory material.
【００４８】この触媒担体の形状は、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、こ
のハニカム材料としては、一般に例えばセラミックス等
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を用い
ることも可能であり、更には触媒粉末そのものをハニカ
ム形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、触媒と排気ガスの触媒面積が大きくな
り、圧力損失も抑えられるため自動車用等として用いる
場合に極めて有利である。Although the shape of the catalyst carrier is not particularly limited, it is usually preferable to use a honeycomb shape. As the honeycomb material, for example, cordierite materials such as ceramics are generally used. It is also possible to use a honeycomb made of a metal material such as stainless steel, and further, the catalyst powder itself may be formed into a honeycomb shape. By making the shape of the catalyst into a honeycomb shape, the area of the catalyst and the exhaust gas becomes large, and the pressure loss is suppressed, which is extremely advantageous when the catalyst is used for an automobile or the like.
【００４９】更に好ましくは、得られた前記排気ガス浄
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。アルカリ金属及び／又はアルカリ土類金
属を担持させることにより、炭化水素の吸着被毒の緩和
およびパラジウムのシンタリングを抑制するという効果
が得られる。使用できるアルカリ金属およびアルカり土
類金属としては、ナトリウム、カリウム、セシウム、マ
グネシウム、カルシウム、ストロンチウム及びバリウム
からなる群より選ばれる一種以上の元素である。More preferably, the obtained catalyst for purifying exhaust gas is impregnated and supported with an alkali metal and / or an alkaline earth metal. By supporting an alkali metal and / or an alkaline earth metal, effects of alleviating adsorption poisoning of hydrocarbons and suppressing sintering of palladium can be obtained. The usable alkali metal and alkaline earth metal are at least one element selected from the group consisting of sodium, potassium, cesium, magnesium, calcium, strontium and barium.
【００５０】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、酢酸塩、水酸化物、硝酸塩、
炭酸塩等の水溶性のものである。これによりパラジウム
の近傍に塩基性元素であるアルカリ金属及び／又はアル
カリ土類金属を分散性良く担持する事が可能となる。こ
の際、アルカリ金属及びアルカリ土類金属の原料化合物
を同時に、あるいは別個に含有させてもよい。The alkali metal and alkaline earth metal compounds which can be used include oxides, acetates, hydroxides, nitrates,
It is water-soluble such as carbonate. This makes it possible to carry a basic element, an alkali metal and / or an alkaline earth metal, in the vicinity of palladium with good dispersibility. At this time, the starting compounds of the alkali metal and the alkaline earth metal may be contained simultaneously or separately.
【００５１】即ち、アルカリ金属化合物及び／又はアル
カリ土類金属化合物からなる粉末の水溶液を、ウオッシ
ュコート成分を担持した上記触媒に含有し、乾燥し、次
いで、空気中及び／又は空気流通下で２００℃〜６００
℃焼成するものである。これは、アルカリ金属およびア
ルカリ土類金属の原料化合物を一度低温で熱処理し酸化
物形態でコート層中に含有させると、後に高温で曝され
ても複合化合物を形成し難くなるからである。かかる焼
成温度が２００℃未満だとアルカリ金属化合物及びアル
カリ土類金属化合物が充分に酸化物形態となるこができ
ず、逆に６００℃を越えると原材料が急激に分解してし
まい、担体がひびわれてしまうことがあるので好ましく
ない。That is, an aqueous solution of a powder comprising an alkali metal compound and / or an alkaline earth metal compound is contained in the above-mentioned catalyst supporting a washcoat component, dried, and then dried in air and / or under a stream of air. ° C to 600
It is baked at ℃. This is because if the alkali metal and alkaline earth metal raw materials are once heat-treated at a low temperature to be contained in the coat layer in the form of an oxide, it becomes difficult to form a composite compound even when exposed later at a high temperature. If the calcination temperature is less than 200 ° C., the alkali metal compound and the alkaline earth metal compound cannot be sufficiently formed into an oxide form. Conversely, if the calcination temperature exceeds 600 ° C., the raw materials are rapidly decomposed and the carrier is cracked. It is not preferable because it may be caused.
【００５２】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。
このハニカム材料としては、一般にセラミックス等のコ
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多く
用いることも可能であり、更には触媒粉末そのものをハ
ニカム形状にしても良い。触媒の形状をハニカム状とす
ることにより、触媒と排気ガスの触媒面積が大きくな
り、圧力損失も抑制できるため自動車用排気ガス浄化触
媒として用いる場合に極めて有効である。The shape of the catalyst carrier is not particularly limited, but usually it is preferable to use it in a honeycomb shape, and the catalyst carrier is used by applying a catalyst powder to various honeycomb-shaped substrates.
As the honeycomb material, cordierite materials such as ceramics are generally used in general, but it is also possible to use many honeycomb materials made of a metal material such as ferrite stainless steel, and further, the catalyst powder itself is formed into a honeycomb shape. May be. By making the shape of the catalyst into a honeycomb shape, the catalyst area of 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.
【００５３】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、
５０〜４００ｇが好ましい。触媒成分が多い程、触媒活
性や触媒寿命の面からは好ましいが、コート層が厚くな
りすぎると、ＨＣ，ＣＯ，ＮＯ等の反応ガスが拡散不良
となるため、これらのガスが触媒に充分接触できなくな
り、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。従って、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 to be attached to the honeycomb material is determined as follows:
50-400 g is preferred. The larger the amount of the catalyst component, the better in terms of catalytic activity and catalyst life. However, if the coating layer is too thick, the reaction gas such as HC, CO, NO, etc. becomes poorly diffused. No longer, the effect of increasing the amount of activity is saturated, and the gas passage resistance is increased. Therefore, the amount of the coat layer is preferably 50 g to 400 g per liter of the catalyst.
【００５４】[0054]
【実施例】本発明を次の調整例・実施例及び比較例によ
り説明する。調製例１ 硝酸ランタン２１．７ｇ，硝酸ニッケル２９０．８ｇを
純水１０００ｇに溶解し、攪拌しながら５％アンモニア
水を加え、ｐＨを８．０に調整した。この溶液を１５０
℃で４時間煮沸した後、スプレードライヤーで乾燥し、
４００℃で２時間、６００℃で２時間、次いで８００℃
で４時間焼成し、Ｌａ0.05ＮｉＯx （ｘは上記各成分の
原子価を薪足するのに必要な酸素原子数）を得た。ここ
で得たＬａ0.05ＮｉＯx 粉末を、アルミナ（Ａ１
2 ０3 ）換算で１０重量％のアルミナゾル２０３９ｇを
純水２５００ｇに分散させた懸濁液に加えた後、攪拌し
ながら５％アンモニア水を加え、ｐＨを８．０に調整し
た。この溶液を１５０℃で４時間煮沸した後、スプレー
ドライヤーで乾燥し、４００℃で２時間、６００℃で２
時間、次いで８００℃で４時間焼成し、Ｌａ0.05ＮｉＯ
x ／Ａ１2 Ｏ3 を得た。EXAMPLES The present invention will be described with reference to the following adjustment examples, examples and comparative examples. Preparation Example 1 21.7 g of lanthanum nitrate and 290.8 g of nickel nitrate were dissolved in 1000 g of pure water, and the pH was adjusted to 8.0 by adding 5% aqueous ammonia with stirring. Add this solution to 150
After boiling at ℃ for 4 hours, dry with a spray dryer,
400 ° C for 2 hours, 600 ° C for 2 hours, then 800 ° C
For 4 hours to obtain La 0.05 NiO x (x is the number of oxygen atoms necessary for adding the valence of each component described above). The obtained La 0.05 NiO x powder was converted to alumina (A1
2 0 3) was added to 10 wt% of alumina sol 2039g suspension dispersed in pure water 2500g in terms of stirring 5% ammonia water was added, the pH was adjusted to 8.0. The solution was boiled at 150 ° C. for 4 hours, dried with a spray dryer, and dried at 400 ° C. for 2 hours and at 600 ° C. for 2 hours.
And then calcined at 800 ° C. for 4 hours, La 0.05 NiO
x / A1 2 O 3 was obtained.
【００５５】調製例２ 硝酸ランタンを４．３ｇとした以外は、調製例１と同様
にして、Ｌａ0.01ＮｉＯx ／Ａ１2 Ｏ3 を得た。[0055] except that the Preparation Example 2 lanthanum nitrate was 4.3g, the same procedure as Preparation Example 1 to obtain a La 0.01 NiO x / A1 2 O 3.
【００５６】調製例３ 硝酸ランタンを３９．０ｇとした以外は調製例１と同様
にして、Ｌａ0.09ＮｉＯx ／Ａ１2 Ｏ3 を得た。 Preparation Example 3 La 0.09 NiO x / A1 2 O 3 was obtained in the same manner as in Preparation Example 1, except that the amount of lanthanum nitrate was changed to 39.0 g.
【００５７】調製例４ 硝酸ランタンの代わりに、硝酸セリウム１９．４ｇを用
いた以外は調製例１と同様にして、Ｃｅ0.05ＮｉＯx ／
Ａｌ2 Ｏを得た。 Preparation Example 4 In the same manner as in Preparation Example 1 except that 19.4 g of cerium nitrate was used instead of lanthanum nitrate, Ce 0.05 NiO x /
Al 2 O was obtained.
【００５８】調製例５ 硝酸ランタンの代わりに、硝酸バリウム１３．１ｇを用
いた以外は調製例１と同様にして、Ｂａ0.05ＮｉＯx ／
ａｌ2 Ｏを得た。 Preparation Example 5 In the same manner as in Preparation Example 1 except that 13.1 g of barium nitrate was used instead of lanthanum nitrate, Ba 0.05 NiO x /
al 2 O was obtained.
【００５９】調製例６ 硝酸ランタン２１．７ｇ、硝酸ニッケル２９０．８ｇを
純水１０００ｇに溶解し、攪拌しながら５％アンモニア
水を加え、ｐＨを８．０に調整した。この溶液を１５０
℃で４時間煮沸した後、スプレードライヤーで乾燥し、
４００℃で２時間、６００℃で２時間、次いで８００℃
で４時間焼成し、Ｌａ0.05ＮｉＯx を得た（ｘ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）。ここ
で得たＬａ0.05ＮｉＯx 粉末を、アルミナ（Ａ１
2 Ｏ3 ）換算で１０重量％のアルミナゾル２０３９ｇを
純水２５００ｇに分散させ懸濁液に加えた後、６０分攪
拌した後、この溶液を１５０℃で４時間煮沸した後、ス
プレードライヤーで乾燥し、４０００℃で２時間、６０
０℃で２時間、次いで８００℃で４時間焼成し、Ｌａ
0.05ＮｉＯx ／Ａ１2 ０3 を得た。 Preparation Example 6 21.7 g of lanthanum nitrate and 290.8 g of nickel nitrate were dissolved in 1000 g of pure water, and the pH was adjusted to 8.0 by adding 5% aqueous ammonia with stirring. Add this solution to 150
After boiling at ℃ for 4 hours, dry with a spray dryer,
400 ° C for 2 hours, 600 ° C for 2 hours, then 800 ° C
For 4 hours to obtain La 0.05 NiO x (x is the number of oxygen atoms required to satisfy the valence of each of the above components). The obtained La 0.05 NiO x powder was converted to alumina (A1
2039 g of alumina sol of 10% by weight in terms of 2 O 3 ) was dispersed in 2500 g of pure water and added to the suspension. After stirring for 60 minutes, the solution was boiled at 150 ° C. for 4 hours, and dried by a spray drier. 60 hours at 4000 ° C for 2 hours
Baking at 0 ° C. for 2 hours, then at 800 ° C. for 4 hours, La
Was obtained 0.05 NiO x / A1 2 0 3 .
【００６０】比較調整例１ 硝酸ランタンを２．２ｇとした以外は調整例１と同様に
してＬａ0.005 ＮｉＯx／Ａ１2 ０3 を得た。[0060] The addition of the Comparative Preparation Example 1 lanthanum nitrate was 2.2g in the same manner as in Preparation Example 1 to obtain a La 0.005 NiO x / A1 2 0 3.
【００６１】比較調整例２ 硝酸ランタンを８６．８ｇとした以外は調整例１と同様
にして、Ｌａ0.2 ＮｉＯx ／Ａ１2 ０を得た。[0061] except that the Comparative Preparation Example 2 86.8 g of lanthanum nitrate in the same manner as in Preparation Example 1 to obtain a La 0.2 NiO x / A1 2 0 .
【００６２】比較調整例３ アルミナゾルを５０９８ｇとし、Ｌａ0.05ＮｉＯx 粉末
とアルミナゾルとを添加する純水を５０００ｇとした以
外は調整例１と同様にして、Ｌａ0.05ＮｉＯx／Ａ１2
０3 を得た。 Comparative Adjustment Example 3 La 0.05 NiO x / A1 2 was prepared in the same manner as in Adjustment Example 1, except that the alumina sol was 5098 g and the pure water to which the La 0.05 NiO x powder and the alumina sol were added was 5000 g.
0 3 was obtained.
【００６３】比較調整例４ アルミナゾルを５０９．８ｇとした以外は調整例１と同
様にして、Ｌａ0.05ＮｉＯx ／Ａ１2 ０3 を得た。[0063] except that the 509.8g Comparative Preparation Example 4 Alumina sol in the same manner as in Preparation Example 1 to obtain a La 0.05 NiO x / A1 2 0 3.
【００６４】比較調製例５ アルミナ（Ａ１2 ０3 ）換算で２０重量％のアルミナゾ
ル１７００ｇを純水２５００ｇに分散させて懸濁液にし
た後、攪拌しながら５％アンモニア水を加え、ｐＨを
８．０に調整した。この溶液を１５０℃で４時間煮沸し
た後、スプレードライヤーで乾燥し、４０００℃で２時
間、６００℃で２時間、次いで８００℃で４時間焼成
し、Ａ１2 ０3 を得た。[0064] After the suspension is dispersed in Comparative Preparation Example 5 Alumina (A1 2 0 3) Pure water 20 wt% alumina sol 1700g in terms of 2500 g, while stirring the 5% ammonia water was added, the pH 8 Was adjusted to 0.0. After boiling for 4 hours at a solution 0.99 ° C., dried in a spray drier, 2 hours at 4000 ° C., 2 hours at 600 ° C., and then calcined 4 hours at 800 ° C., to obtain a A1 2 0 3.
【００６５】比較調製例６ 硝酸ランタン２１．７ｇ、硝酸ニッケル２９０．８ｇを
純水１０００ｇに溶解し、攪拌しながら５％アンモニア
水を加え、ｐＨを８．０に調整した。この溶液を１５０
℃で４時間煮沸した後、スプレードライヤーで乾燥し、
４００℃で２時間、６００℃で２時間、次いで８００℃
で４時間焼成し、Ｌａ0.05ＮｉＯx （ｘは上記各成分の
原子価を義足するのに必要な酸素原子数）を得た。 Comparative Preparation Example 6 21.7 g of lanthanum nitrate and 290.8 g of nickel nitrate were dissolved in 1000 g of pure water, and the pH was adjusted to 8.0 by adding 5% aqueous ammonia with stirring. Add this solution to 150
After boiling at ℃ for 4 hours, dry with a spray dryer,
400 ° C for 2 hours, 600 ° C for 2 hours, then 800 ° C
For 4 hours to obtain La 0.05 NiO x (x is the number of oxygen atoms required to add the valence of each component described above).
【００６６】実施例１ 調製例１で得たＬａ0.05ＮｉＯx ／Ａ１2 ０3 にパラジ
ウムを１．０重量％担持した粉末（粉末Ａ）６９２ｇ
と、ランタンを１モル％（Ｌａ2 Ｏ3 に換算して２重量
％）とジルコニウムを３２モル％（Ｚｒ０2 に換算して
２５重量％）含むセリウム酸化物粉末にパラジウム０．
７５重量ｇを担持した粉末（粉末Ｂ）４８０ｇと、硝酸
水溶液１２００ｇとを磁性ボールミルに投入し、混合粉
砕してスラリー液を得た。このスラリー液をコージエラ
イト質モノリス担体（１．３Ｌ、４００セル）に付着さ
せ、４００℃で１時間焼成し、コート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、上記触媒成分担持コージエライ
ト質モノリス担体に酢酸バリウム溶液を付着させた後、
４００℃で１時間焼成し、ＢａＯ１５ｇ／Ｌを含有させ
た。[0066] La 0.05 NiO x / A1 2 0 1.0 Palladium 3 wt% on the powder obtained in Example 1 Preparation Example 1 (Powder A) 692 g
And cerium oxide powder containing 1 mol% of lanthanum ( 2 % by weight in terms of La 2 O 3 ) and 32 mol% of zirconium (25% by weight in terms of ZrO 2 ).
480 g of a powder (powder B) supporting 75 g by weight and 1200 g of a nitric acid aqueous solution were charged into a magnetic ball mill and mixed and pulverized to obtain a slurry liquid. This slurry liquid was attached to a cordierite-based monolithic carrier (1.3 L, 400 cells), baked at 400 ° C. for 1 hour, and a coat layer weight of 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Then, after attaching the barium acetate solution to the catalyst component-carrying cordierite-based monolithic carrier,
It was calcined at 400 ° C. for 1 hour and contained 15 g / L of BaO.
【００６７】実施例２ 調製例２で得たＬａ0.01ＮｉＯx ／Ａ１2 Ｏ3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａＯ１５ｇ／Ｌを含有させた。[0067] Example 2 except for using La 0.01 NiO x / A1 2 O 3 obtained in Preparation Example 2, coated layer weight in the same manner as in Example 1 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
It contained 15 g / L of aO.
【００６８】実施例３ 調製例３で得たＬａ0.09ＮｉＯx ／Ａｌ2 ０3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａＯ１５ｇ／Ｌを含有させた。[0068] Example 3 except for using La 0.09 NiO x / Al 2 0 3 obtained in Preparation Example 3, the coating layer weight in the same manner as in Example 1 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
It contained 15 g / L of aO.
【００６９】実施例４ 調整例４で得たＣｅ0.05ＮｉＯx ／Ａ１2 ０3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た．次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａ０１５ｇ／Ｌを含有させた。[0069] Example 4 except for using Ce 0.05 NiO x / A1 2 0 3 obtained in Preparation Example 4, the same procedure as in Example 1 coated layer weight 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
a015 g / L.
【００７０】実施例５ 調整例５で得たＢａ0.05ＮｉＯx ／Ａ１2 ０3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａ０１５ｇ／Ｌを含有させた。[0070] Example 5 except for using Ba 0.05 NiO x / A1 2 0 3 obtained in Preparation Example 5, Example 1 coating layer weight in the same manner as 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
a015 g / L.
【００７１】実施例６ 調整例６で得たＬａ0.05ＮｉＯx ／Ａ１2 ０3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａ０１５ｇ／Ｌを含有させた。[0071] Example 6 except for using La 0.05 NiO x / A1 2 0 3 obtained in Preparation Example 6, Example 1 coating layer weight in the same manner as 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
a015 g / L.
【００７２】比較例１ 比較調整例１のＬａ0.005 ＮｉＯx ／Ａ１2 ０3 を用い
た以外は、実施例１と同様にしてコート層重量１６０ｇ
／Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／
Ｌ）の触媒を得た。次いで、実施例１と同様にして酢酸
バリウム溶液を付着させた後、４００℃で１時間焼成
し、Ｂａ０１５ｇ／Ｌを含有させた。[0072] except for using La 0.005 NiO x / A1 2 0 3 Comparative Example 1 Comparative Preparation Example 1, the same way coated layer weight 160g Example 1
/ L, palladium carrying amount 40 g / cf (1.42 g /
The catalyst of L) was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour to contain Ba015 g / L.
【００７３】比較例２ 比較調整例２のＬａ0.2 ＮｉＯx ／Ａ１2 ０3 を用いた
以外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａ０１５ｇ／Ｌを含有させた。[0073] Comparative Example 2 except for using La 0.2 NiO x / A1 2 0 3 of Comparative Preparation Example 2, Example 1 coating layer weight in the same manner as 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
a015 g / L.
【００７４】比較例３ 比較例３のＬａ0.05ＮｉＯx ／Ａ１2 ０3 を用いた以外
は、実施例１と同様にしてコート層重量１６０ｇ／Ｌ、
パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）の触
媒を得た。次いで、実施例１と同様にして酢酸バリウム
溶液を付着させた後、４００℃で１時間焼成し、Ｂａ０
１５ｇ／Ｌを含有させた。[0074] except for using La 0.05 NiO x / A1 2 0 3 Comparative Example 3 Comparative Example 3, the coating layer weight in the same manner as in Example 1 160 g / L,
A catalyst having a palladium loading of 40 g / cf (1.42 g / L) was obtained. Next, after a barium acetate solution was applied in the same manner as in Example 1, the barium acetate solution was baked at 400 ° C. for 1 hour to obtain Ba0.
It contained 15 g / L.
【００７５】比較例４ 比較調整例のＬａ0.05ＮｉＯx ／Ａ１2 ０3 を用いた以
外は、実施例１と同様にしてコート層重量１６０ｇ／
Ｌ、パラジウム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）
の触媒を得た。次いで、実施例１と同様にして酢酸バリ
ウム溶液を付着させた後、４００℃で１時間焼成し、Ｂ
ａ０１５ｇ／Ｌを含有させた。[0075] Comparative Example 4 except for using the comparative example of adjusting La 0.05 NiO x / A1 2 0 3, coating layer weight in the same manner as in Example 1 160 g /
L, palladium carrying amount 40 g / cf (1.42 g / L)
Was obtained. Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour.
a015 g / L.
【００７６】比較例５ 比較調整例５のＡ１2 ０3 を用いた以外は、実施例１と
同様にしてコート層重量１６０ｇ／Ｌ、パラジウム担持
量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）の触媒を得た。次い
で、実施例１と同様にして酢酸バリウム溶液を付着させ
た後、４００℃で１時間焼成し、Ｂａ０１５ｇ／Ｌを含
有させた。[0076] catalyst except for using the A1 2 0 3 Comparative Example 5 Comparative Preparation Example 5, coating layer weight 160 g / L in the same manner as in Example 1, palladium weight 40g / cf (1.42g / L) I got Next, a barium acetate solution was applied in the same manner as in Example 1 and then calcined at 400 ° C. for 1 hour to contain Ba015 g / L.
【００７７】比較例６ 比較調整例６のＬａ0.05ＮｉＯx を用いた以外は、実施
例１と同様にしてコート層重量１６０ｇ／Ｌ、パラジウ
ム担持量４０ｇ／ｃｆ（１．４２ｇ／Ｌ）の触媒を得
た。次いで、実施例１と同様にして酢酸バリウム溶液を
付着させた後、４００℃で１時間焼成し、Ｂａ０１５ｇ
／Ｌを含有させた。 Comparative Example 6 A catalyst having a coat layer weight of 160 g / L and a palladium carrying amount of 40 g / cf (1.42 g / L) was prepared in the same manner as in Example 1 except that La 0.05 NiO x of Comparative Adjustment Example 6 was used. I got Next, a barium acetate solution was applied in the same manner as in Example 1 and calcined at 400 ° C. for 1 hour to obtain Ba015 g
/ L.
【００７８】前記実施例１〜６及び比較例１〜６で得ら
れた排気ガス浄化用触媒の触媒組成を表１に示す。Table 1 shows the catalyst compositions of the exhaust gas purifying catalysts obtained in Examples 1 to 6 and Comparative Examples 1 to 6.
【００７９】[0079]
【表１】 試験例 前記実施例１〜６及び比較例１〜６で得られた排気ガス
浄化触媒について、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。[Table 1] Test Examples The exhaust gas purifying catalysts obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were subjected to durability under the following durability conditions, and then were evaluated for catalytic activity under the following evaluation conditions.
【００８０】 [0080]
【００８１】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（丁５
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
The temperature at which the conversion of O and NOx reaches 50%
0 / ° C.), and the results are shown in Table 2.
【００８２】 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
（％）として以下の式（１〜３）により決定し、その結
果を表２に示す。[0082] The purifying performance of each exhaust gas purifying catalyst after the endurance was determined as the average conversion (%) of HC, CO and NOx in the stoichiometric atmosphere by the following equations (1 to 3), and the results are shown in Table 2.
【００８３】[0083]
【数１】 (Equation 1)
【００８４】[0084]
【数２】 (Equation 2)
【００８５】[0085]
【数３】 (Equation 3)
【００８６】[0086]
【表２】 [Table 2]
【００８７】[0087]
【発明の効果】本発明の排気ガス浄化用触媒は、高温下
における耐久性に優れ、貴金属種のシンタリング抑制
し、更に、結晶構造が均一で高温での構造安定性を向上
させ、活性相の分散状態を高めて貴金属の活性化促進作
用を向上できる。従って、従来の触媒よりも耐久性が向
上し、幅広い排気ガス組成雰囲気下で、耐久後において
も優れた低温活性と浄化性能を有する。The exhaust gas purifying catalyst of the present invention has excellent durability at high temperatures, suppresses sintering of noble metal species, has a uniform crystal structure, improves structural stability at high temperatures, and has an active phase. Of the noble metal can be enhanced to enhance the dispersion promoting state of the noble metal. Therefore, the durability is improved as compared with the conventional catalyst, and the catalyst has excellent low-temperature activity and purification performance even after durability under a wide range of exhaust gas composition atmospheres.
【００８８】また、本発明の排気ガス浄化用触媒の製造
方法は、比表面積が大きく、微細な細孔構造を有し、担
持材料を高分散に担持できる、上記の本発明の排気ガス
浄化触媒を効率良く製造できる。Further, according to the method for producing an exhaust gas purifying catalyst of the present invention, the exhaust gas purifying catalyst of the present invention has a large specific surface area, has a fine pore structure, and can carry a supporting material in a highly dispersed state. Can be manufactured efficiently.
フロントページの続き Ｆターム(参考） 3G091 AA17 AB01 AB03 BA02 BA03 BA11 BA14 BA15 BA19 BA38 BA39 FA02 FA04 FB02 FB03 FB10 FB11 FB12 FC07 FC08 GA06 GB01W GB01X GB02W GB03W GB04W GB05W GB07W GB10W GB13W GB15W GB16W GB17X 4D048 AA06 AA13 AA18 AB01 AB02 AB05 BA03X BA03Y BA10Y BA15X BA15Y BA18X BA18Y BA19X BA19Y BA31X BA31Y BA38X BA38Y BB02 CC39 4G069 AA01 AA03 AA08 AA09 AA12 BA01A BA01B BA01C BA13B BA37 BB06A BB06B BB06C BC01A BC08A BC13A BC13B BC42A BC42B BC43A BC43B BC68A BC68B BC72A BC72B CA03 CA09 CA13 CA14 CA15 DA06 EA19 EC23 FA01 FA02 FB06 FB30 FC02 FC08 FC09Continued on front page F-term (reference) 3G091 AA17 AB01 AB03 BA02 BA03 BA11 BA14 BA15 BA19 BA38 BA39 FA02 FA04 FB02 FB03 FB10 FB11 FB12 FC07 FC08 GA06 GB01W GB01X GB02W GB03W GB04W GB05W GB07W GB10W GB13W GB15W AGB18A GBA BA03X BA03Y BA10Y BA15X BA15Y BA18X BA18Y BA19X BA19Y BA31X BA31Y BA38X BA38Y BB02 CC39 4G069 AA01 AA03 AA08 AA09 AA12 BA01A BA01B BA01C BA13B BA37 BB06A BB06B BB06BBC BCBC BCA BCBC BC BC BC BC BC FA02 FB06 FB30 FC02 FC08 FC09
Claims (6)
であって、触媒成分として次の一般式； Ａx Ｎｉy Ｏz （式中、ＡはＬａ、Ｃｅ及びＢａからなる群より選ばれ
た少なくとも一種の元素であり、ｘ，ｙ及びｚは各元素
の原子比率を示し、ｙ＝１．０の時、ｘ＝０．０１以上
０．１未満、ｚ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）で表されるペロブスカイト型複
合酸化物と、アルミナと、パラジウムとを含むことを特
徴とする排気ガス浄化用触媒。An integrated catalyst having a catalyst component-supporting layer, wherein the catalyst component is represented by the following general formula: A x Ni y O z (where A is selected from the group consisting of La, Ce and Ba) X, y and z indicate the atomic ratio of each element. When y = 1.0, x = 0.01 or more and less than 0.1, and z denotes the valence of each of the above components. An exhaust gas purifying catalyst comprising: a perovskite-type composite oxide represented by the following formula: (a number of oxygen atoms required to satisfy the above), alumina, and palladium.
て、上記ペロブスカイト型複合酸化物がアルミナ上に高
分散し、かつ、上記ペロブスカイト型複合酸化物とアル
ミナとの混合比は、ペロブスカイト型複合酸化物中のＮ
ｉとアルミナ中のＡｌがモル比でＮｉ／Ａｌ＝０．１５
〜１．０であることを特徴とする排気ガス浄化用触媒。2. The exhaust gas purifying catalyst according to claim 1, wherein the perovskite-type composite oxide is highly dispersed on alumina, and a mixing ratio between the perovskite-type composite oxide and alumina is perovskite-type composite oxide. N in things
i / Al in alumina is molar ratio of Ni / Al = 0.15
A catalyst for purifying exhaust gas, characterized by being in the range of 1.0 to 1.0.
いて、ペロブスカイト型複合酸化物が高分散したアルミ
ナに、パラジウムが担持されて成ることを特徴とする排
気ガス浄化用触媒。3. The exhaust gas purifying catalyst according to claim 2, wherein palladium is carried on alumina in which a perovskite-type composite oxide is highly dispersed.
ス浄化用触媒に、更にアルカリ金属およびアルカリ土類
金属から成る群より選ばれる１種が含有されることを特
徴とする排気ガス浄化用触媒。4. The exhaust gas purifying catalyst according to claim 1, further comprising one selected from the group consisting of an alkali metal and an alkaline earth metal. Purification catalyst.
製造するにあたり、請求項１〜３いずれかの項記載のペ
ロブスカイト型複合酸化物と、微粒子アルミナ水和物コ
ロイドとを水に分散させた後、水分を除去して乾燥し、
焼成し、得られたペロブスカイト型複合酸化物が分散し
たアルミナ粉末に、パラジウムを担持することを特徴と
する排気ガス浄化用触媒の製造方法。5. In producing the catalyst according to any one of claims 1 to 3, the perovskite-type composite oxide according to any one of claims 1 to 3 and a fine particle alumina hydrate colloid are dissolved in water. After dispersing, remove water and dry,
A method for producing an exhaust gas purifying catalyst, characterized in that palladium is supported on alumina powder in which a perovskite-type composite oxide obtained by calcining is dispersed.
ス浄化用触媒を製造するにあたり、請求項１〜３いずれ
かの項記載のペロブスカイト型複合酸化物と、微粒子ア
ルミナ水和物コロイドとを水に分散させた後、アンモニ
ア水、炭酸アンモニウム及び炭酸水素アンモニウムから
成る群より選ばれた少なくとも一種の水溶液を加え、ｐ
Ｈを７．０〜９．０の範囲になるように調整した後、水
分を除去して乾燥し、焼成し、得られたペロブスカイト
型複合酸化物が分散したアルミナ粉末に、パラジウムを
担持することを特徴とする排気ガス浄化用触媒の製造方
法。6. A perovskite-type composite oxide according to any one of claims 1 to 3, and a particulate alumina hydrate colloid for producing the exhaust gas purifying catalyst according to any one of claims 1 to 3. Is dispersed in water, and at least one aqueous solution selected from the group consisting of aqueous ammonia, ammonium carbonate and ammonium hydrogen carbonate is added, and p is added.
After adjusting H to be in the range of 7.0 to 9.0, removing water, drying and calcining, and supporting palladium on the obtained alumina powder in which the perovskite-type composite oxide is dispersed. A method for producing an exhaust gas purifying catalyst, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10227275A JP2000051700A (en) | 1998-08-11 | 1998-08-11 | Exhaust emission purifying catalyst and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10227275A JP2000051700A (en) | 1998-08-11 | 1998-08-11 | Exhaust emission purifying catalyst and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2000051700A true JP2000051700A (en) | 2000-02-22 |
Family
ID=16858275
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10227275A Withdrawn JP2000051700A (en) | 1998-08-11 | 1998-08-11 | Exhaust emission purifying catalyst and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2000051700A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006205021A (en) * | 2005-01-27 | 2006-08-10 | Mitsubishi Heavy Ind Ltd | Composite oxide catalyst |
| JP2008513733A (en) * | 2004-08-12 | 2008-05-01 | サウスウエスト リサーチ インスティテュート | Component evaluation using non-engine-based test systems (component evaluation using non-engineered tests system) |
| JP2010051962A (en) * | 2009-11-30 | 2010-03-11 | Mitsubishi Heavy Ind Ltd | Catalyst for purifying exhaust gas and regeneration treatment method of the same |
| JP2011041951A (en) * | 2010-11-15 | 2011-03-03 | Mitsubishi Heavy Ind Ltd | Catalyst for purifying exhaust gas and regeneration treatment method of the same |
| WO2014038294A1 (en) * | 2012-09-10 | 2014-03-13 | 日産自動車株式会社 | Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method for producing exhaust gas purification catalyst |
| CN111801161A (en) * | 2018-05-11 | 2020-10-20 | 株式会社村田制作所 | Supported catalyst for organic matter decomposition and organic matter decomposition device |
-
1998
- 1998-08-11 JP JP10227275A patent/JP2000051700A/en not_active Withdrawn
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008513733A (en) * | 2004-08-12 | 2008-05-01 | サウスウエスト リサーチ インスティテュート | Component evaluation using non-engine-based test systems (component evaluation using non-engineered tests system) |
| JP2006205021A (en) * | 2005-01-27 | 2006-08-10 | Mitsubishi Heavy Ind Ltd | Composite oxide catalyst |
| JP2010051962A (en) * | 2009-11-30 | 2010-03-11 | Mitsubishi Heavy Ind Ltd | Catalyst for purifying exhaust gas and regeneration treatment method of the same |
| JP4665047B2 (en) * | 2009-11-30 | 2011-04-06 | 三菱重工業株式会社 | Exhaust gas purification catalyst and method for regenerating the same |
| JP2011041951A (en) * | 2010-11-15 | 2011-03-03 | Mitsubishi Heavy Ind Ltd | Catalyst for purifying exhaust gas and regeneration treatment method of the same |
| JP5885004B2 (en) * | 2012-09-10 | 2016-03-15 | 日産自動車株式会社 | Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method of manufacturing exhaust gas purification catalyst |
| WO2014038294A1 (en) * | 2012-09-10 | 2014-03-13 | 日産自動車株式会社 | Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method for producing exhaust gas purification catalyst |
| US9352301B2 (en) | 2012-09-10 | 2016-05-31 | Nissan Motor Co., Ltd. | Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method for producing exhaust gas purification catalyst |
| JPWO2014038294A1 (en) * | 2012-09-10 | 2016-08-08 | 日産自動車株式会社 | Exhaust gas purification catalyst, exhaust gas purification monolith catalyst, and method of manufacturing exhaust gas purification catalyst |
| CN111801161A (en) * | 2018-05-11 | 2020-10-20 | 株式会社村田制作所 | Supported catalyst for organic matter decomposition and organic matter decomposition device |
| CN111818998A (en) * | 2018-05-11 | 2020-10-23 | 株式会社村田制作所 | Catalyst for organic matter decomposition and organic matter decomposition device |
| CN111801161B (en) * | 2018-05-11 | 2023-04-04 | 株式会社村田制作所 | Supported catalyst for organic decomposition and organic decomposition device |
| CN111818998B (en) * | 2018-05-11 | 2023-04-04 | 株式会社村田制作所 | Catalyst for organic matter decomposition and organic matter decomposition device |
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