JPS61222539A - Preparation of monolithic type exhaust gas purifying catalyst - Google Patents
Preparation of monolithic type exhaust gas purifying catalystInfo
- Publication number
- JPS61222539A JPS61222539A JP60062060A JP6206085A JPS61222539A JP S61222539 A JPS61222539 A JP S61222539A JP 60062060 A JP60062060 A JP 60062060A JP 6206085 A JP6206085 A JP 6206085A JP S61222539 A JPS61222539 A JP S61222539A
- Authority
- JP
- Japan
- Prior art keywords
- supported
- activated alumina
- catalyst
- rhodium
- powder
- 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 87
- 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 55
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 40
- 239000000843 powder Substances 0.000 claims abstract description 35
- 239000010948 rhodium Substances 0.000 claims abstract description 33
- UNJPQTDTZAKTFK-UHFFFAOYSA-K cerium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Ce+3] UNJPQTDTZAKTFK-UHFFFAOYSA-K 0.000 claims abstract description 32
- 239000002002 slurry Substances 0.000 claims abstract description 28
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 21
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 21
- 239000000203 mixture Substances 0.000 claims abstract description 15
- 239000011248 coating agent Substances 0.000 claims abstract description 14
- 238000000576 coating method Methods 0.000 claims abstract description 14
- 150000001875 compounds Chemical class 0.000 claims abstract description 8
- 150000003284 rhodium compounds Chemical class 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 34
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000002245 particle Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 6
- 150000003755 zirconium compounds Chemical class 0.000 claims description 5
- 239000011164 primary particle Substances 0.000 claims description 4
- 239000011163 secondary particle Substances 0.000 claims description 4
- 150000002604 lanthanum compounds Chemical class 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 abstract description 7
- 239000002184 metal Substances 0.000 abstract description 6
- -1 platinum group metals Chemical class 0.000 abstract description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 15
- 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 14
- 238000000746 purification Methods 0.000 description 14
- 239000007789 gas Substances 0.000 description 13
- 239000007864 aqueous solution Substances 0.000 description 10
- 229910000420 cerium oxide Inorganic materials 0.000 description 8
- 239000000446 fuel Substances 0.000 description 8
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 8
- 238000011156 evaluation Methods 0.000 description 7
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- FCUFAHVIZMPWGD-UHFFFAOYSA-N [O-][N+](=O)[Pt](N)(N)[N+]([O-])=O Chemical compound [O-][N+](=O)[Pt](N)(N)[N+]([O-])=O FCUFAHVIZMPWGD-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 229910052684 Cerium Inorganic materials 0.000 description 5
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 229910052763 palladium Inorganic materials 0.000 description 5
- 229910052697 platinum Inorganic materials 0.000 description 5
- 239000002344 surface layer Substances 0.000 description 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 4
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 4
- 239000006255 coating slurry Substances 0.000 description 4
- 229910017604 nitric acid Inorganic materials 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 150000003839 salts Chemical class 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- 239000000969 carrier Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 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 3
- 239000006185 dispersion Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- FGHSTPNOXKDLKU-UHFFFAOYSA-N nitric acid;hydrate Chemical compound O.O[N+]([O-])=O FGHSTPNOXKDLKU-UHFFFAOYSA-N 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- 150000000703 Cerium Chemical class 0.000 description 2
- 229910017569 La2(CO3)3 Inorganic materials 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- 229910001593 boehmite Inorganic materials 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- NZPIUJUFIFZSPW-UHFFFAOYSA-H lanthanum carbonate Chemical compound [La+3].[La+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O NZPIUJUFIFZSPW-UHFFFAOYSA-H 0.000 description 2
- 229960001633 lanthanum carbonate Drugs 0.000 description 2
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 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
- 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 2
- 239000000243 solution Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- 229910000505 Al2TiO5 Inorganic materials 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical class [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
- 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
- 230000001133 acceleration Effects 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- HEHRHMRHPUNLIR-UHFFFAOYSA-N aluminum;hydroxy-[hydroxy(oxo)silyl]oxy-oxosilane;lithium Chemical compound [Li].[Al].O[Si](=O)O[Si](O)=O.O[Si](=O)O[Si](O)=O HEHRHMRHPUNLIR-UHFFFAOYSA-N 0.000 description 1
- CNLWCVNCHLKFHK-UHFFFAOYSA-N aluminum;lithium;dioxido(oxo)silane Chemical compound [Li+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O CNLWCVNCHLKFHK-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 239000012736 aqueous medium Substances 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 235000019402 calcium peroxide Nutrition 0.000 description 1
- 229910002090 carbon oxide Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 150000001785 cerium compounds Chemical class 0.000 description 1
- HZADGDCWYTUEDJ-UHFFFAOYSA-M cerium(3+);hydroxide Chemical compound [OH-].[Ce+3] HZADGDCWYTUEDJ-UHFFFAOYSA-M 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 229910001385 heavy metal Inorganic materials 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000003100 immobilizing effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 230000000977 initiatory effect Effects 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- YXEUGTSPQFTXTR-UHFFFAOYSA-K lanthanum(3+);trihydroxide Chemical compound [OH-].[OH-].[OH-].[La+3] YXEUGTSPQFTXTR-UHFFFAOYSA-K 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 229910052919 magnesium silicate Inorganic materials 0.000 description 1
- 235000019792 magnesium silicate Nutrition 0.000 description 1
- 239000000391 magnesium silicate Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- UJVRJBAUJYZFIX-UHFFFAOYSA-N nitric acid;oxozirconium Chemical compound [Zr]=O.O[N+]([O-])=O.O[N+]([O-])=O UJVRJBAUJYZFIX-UHFFFAOYSA-N 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- MMKQUGHLEMYQSG-UHFFFAOYSA-N oxygen(2-);praseodymium(3+) Chemical compound [O-2].[O-2].[O-2].[Pr+3].[Pr+3] MMKQUGHLEMYQSG-UHFFFAOYSA-N 0.000 description 1
- 229910052670 petalite Inorganic materials 0.000 description 1
- 229910003447 praseodymium oxide Inorganic materials 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- AABBHSMFGKYLKE-SNAWJCMRSA-N propan-2-yl (e)-but-2-enoate Chemical compound C\C=C\C(=O)OC(C)C AABBHSMFGKYLKE-SNAWJCMRSA-N 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 229910001954 samarium oxide Inorganic materials 0.000 description 1
- 229940075630 samarium oxide Drugs 0.000 description 1
- FKTOIHSPIPYAPE-UHFFFAOYSA-N samarium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[Sm+3].[Sm+3] FKTOIHSPIPYAPE-UHFFFAOYSA-N 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 229910052642 spodumene Inorganic materials 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- JUWGUJSXVOBPHP-UHFFFAOYSA-B titanium(4+);tetraphosphate Chemical compound [Ti+4].[Ti+4].[Ti+4].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O JUWGUJSXVOBPHP-UHFFFAOYSA-B 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 239000006200 vaporizer Substances 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は排気ガス浄化用一体構造型触媒の製造方法に関
するものである。詳しく述べると゛本発明は排気ガス中
に含まれる有害成分である炭化水素(以下HCとする)
、−酸化炭素(以下COとする)および窒素酸化物(以
下NOxとする)を除去するための一体構造型触媒の製
造方法に関するものである。さらに詳しく述べると本発
明は、内燃機関が空気対燃料比の化学量論的当量点近辺
で運転される際、その排ガス中のHC,CoおよびNO
xを同時に、安定して実質的に無害化でき、かつ800
℃以上の高温に曝されでも劣化が少ない排気ガス浄化用
一体構造型触媒の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a monolithic catalyst for exhaust gas purification. To explain in detail, the present invention deals with hydrocarbons (hereinafter referred to as HC), which are harmful components contained in exhaust gas.
, - relates to a method for producing a monolithic catalyst for removing carbon oxides (hereinafter referred to as CO) and nitrogen oxides (hereinafter referred to as NOx). More specifically, the present invention provides a method for reducing HC, Co, and NO in the exhaust gas of an internal combustion engine when it is operated near the stoichiometric point of air-to-fuel ratio.
x can be made stable and substantially harmless at the same time, and 800
The present invention relates to a method for manufacturing an integrally structured catalyst for exhaust gas purification that exhibits little deterioration even when exposed to high temperatures of .degree. C. or higher.
内燃機関の排気ガス中のHC,CoおよびNOx3成分
を1個の触媒コンバーターで同時除去するための触媒、
いわゆる三元触媒は53年規制対策車の一部に装着され
、最近では燃費改良対策のためもあって、三元触媒装着
車が増加している。この場合触媒の装着位置は床下が多
く、他ニエンジンのマニホールド直下に装着するケース
もある。A catalyst for simultaneously removing three components of HC, Co and NOx in exhaust gas of an internal combustion engine with one catalytic converter,
So-called three-way catalysts are installed in some cars that comply with the 1953 regulations, and recently, the number of cars equipped with three-way catalysts has been increasing, partly as a measure to improve fuel efficiency. In this case, the catalyst is often installed under the floor, and in some cases it is installed directly under the manifold of other engines.
この三元触媒コンバーターを装備したエンジンは化学量
論的な空燃比(A/F )近辺で運転された時、上記3
成分を最も効果的に浄化した排ガスを排出するが、さら
に三元触媒をよシ効果的に作用させるため、燃料を噴射
ポンプで一定人/Fを保つように供給する電子制御燃料
噴射装置やベンチュリー気化器を用いてA / Fを制
御する方式が採用されている。しかし制御方式によって
はA/Fが化学量論的な当量点から離れてかなシ広い範
囲で変動する場合があυ、また、加減速等の急激な運転
の変化の場合には一体構造型触媒の温度急上昇による溶
融を防止するため、燃料供給が一部または全部カットさ
れ、大巾にリーン雰囲気にさらされる場合もある。When an engine equipped with this three-way catalytic converter is operated near the stoichiometric air/fuel ratio (A/F), the
Exhaust gas is discharged with the components most effectively purified, but in order to make the three-way catalyst work even more effectively, an electronically controlled fuel injection device or venturi is used to supply fuel using an injection pump to maintain a constant rate of F/F. A method is adopted in which A/F is controlled using a vaporizer. However, depending on the control method, the A/F may vary over a wide range away from the stoichiometric equivalence point, and in the case of sudden changes in operation such as acceleration/deceleration, the integral structure catalyst In order to prevent melting due to a sudden rise in temperature, fuel supply may be partially or completely cut off and the fuel may be exposed to a lean atmosphere.
すなわち、三元触媒は常に理想的なA/F運転時の排ガ
スに曝されるわけでなく、このような条件下で触媒が高
温に曝される場合には触媒中に含まれる成分特にロジウ
ムと白金は熱的劣化を受は易い。従って広い範囲のA/
Fでの運転でも安定した浄化性能を示し、劣化の少ない
三元触媒が望まれることになる。このような三元触媒が
えられれば、同一浄化性能を保ちながら、担持される白
金属元素の使用量を減少することができるため有利であ
り、このような高性能の触媒が望まれていた。In other words, the three-way catalyst is not always exposed to ideal exhaust gas during A/F operation, and when the catalyst is exposed to high temperatures under such conditions, the components contained in the catalyst, especially rhodium, Platinum is susceptible to thermal degradation. Therefore, a wide range of A/
A three-way catalyst that exhibits stable purification performance even when operated at F and exhibits little deterioration is desired. If such a three-way catalyst could be obtained, it would be advantageous because it would be possible to reduce the amount of supported platinum metal elements while maintaining the same purification performance, and such a high-performance catalyst was desired. .
従来この要望をみたすために酸素貯蔵能を有する物質と
してセリウム酸化物を白金属元素と共存させて使用する
ことが広く知られておシ、セリウム酸化物を分散性よく
担持させるためにはセリウム化合物を硝酸セリウム等の
如き塩類の形で活性アルミナに担持させる方法が行われ
ていた。しかしながら活性アルミナに硝酸セリウムのよ
うな水溶性の塩の形態でセリウム分を担持する方法には
、耐久性とくに耐熱耐久性に劣るという欠点があった。Conventionally, in order to meet this demand, it has been widely known that cerium oxide is used in coexistence with a platinum metal element as a substance with oxygen storage ability. A method of supporting activated alumina in the form of a salt such as cerium nitrate has been used. However, the method of supporting activated alumina with cerium in the form of a water-soluble salt such as cerium nitrate has the drawback of poor durability, particularly poor heat resistance.
また、特開昭58−122044号には触媒成分原料を
炭酸塩の形でたとえばランタンを炭酸ランタンの形で使
用する方法が記載されている。しかしこの炭酸ランタン
は活性アルミナや触媒活性物質からなる触媒組成物を水
性媒体中でスラリー状に微粉砕化する際に少量の無機酸
または有機酸と共存させると炭酸根がこれら酸根と反応
し、スラリーのチキン性が強くなシ、コーティング用組
成物としては、スムーズにはコーティングし難い組成物
となってしまう欠点がある。Further, JP-A-58-122044 describes a method in which the catalyst component raw material is used in the form of carbonate, for example, lanthanum in the form of lanthanum carbonate. However, when this lanthanum carbonate is made to coexist with a small amount of inorganic or organic acid when a catalyst composition consisting of activated alumina or a catalytically active substance is pulverized into a slurry in an aqueous medium, the carbonate radicals react with these acid radicals. As a coating composition, the slurry has a strong chicken-like character, which makes it difficult to coat smoothly.
本発明の目的はこれら従来法の欠点を解消する方法を提
供することにある。本発明者らはこの目的を達成するべ
く検討した結果、セリウム原料として水酸化セリウム粉
末を使用すると、硝酸セリウムを用いた従来の触媒に比
べて耐熱耐久性が飛躍的に向上し、かつ低温活性も向上
すること、とくに水酸化セリウムとして一定の含水量範
囲で一定の粒度の微粒子のものを使用すると分散性が好
適にコントロールされ、かつコーテイング液の製造の際
に少量の酸を添加してスラリー状に微粉末化する際にも
良好な分散液を製造することが可能となること、を見い
出した。An object of the present invention is to provide a method that overcomes these drawbacks of the conventional methods. As a result of studies conducted by the present inventors to achieve this objective, the use of cerium hydroxide powder as a cerium raw material dramatically improves heat resistance and durability compared to conventional catalysts using cerium nitrate, and shows low-temperature activity. In particular, using fine particles of a certain particle size within a certain water content range as cerium hydroxide allows for better control of dispersibility, and adding a small amount of acid during the production of a coating liquid to create a slurry. It has been found that it is possible to produce a good dispersion liquid even when pulverized into a fine powder.
本発明は以下の如く特定することができるものである。The present invention can be specified as follows.
(1)活性アルミナ粉末に少なくとも一種の白金族元素
の化合物を分散担持し、当該白金族元素を活性アルミナ
上に固定せしめたのち、さらにこれを水酸化セリウム粉
末と共に水性スラリー化せしめ、えられたスラリー組成
物を一体構造型担体にコーティング処理し、その後活性
アルミナ粉末にロジウム化合物を分散担持し、ロジウム
を活性アルミナ上に固定せしめたのち、水性スラリー化
せしめえられたスラリーを前記コーティング処理した該
担体に追加コーティングすることを特徴とする一体構造
型排ガス浄化用触媒の製造方法。(1) A compound of at least one platinum group element is dispersed and supported on activated alumina powder, the platinum group element is fixed on the activated alumina, and then this is further formed into an aqueous slurry with cerium hydroxide powder. A slurry composition is coated on a monolithic carrier, a rhodium compound is dispersed and supported on activated alumina powder, and rhodium is fixed on the activated alumina. A method for producing an integrated structure exhaust gas purifying catalyst characterized by additionally coating a carrier.
(2)活性アルミナ粉末に少なくとも一種の白金族元素
の化合物を分散担持し、当該白金族元素を活性アルミナ
上に固定せしめ、さらにこれを水酸化セリウム粉末と共
に水性スラリー化せしめ、えられたスラリー組成物を一
体構造型担体にコーティング処理し、その後活性アルミ
ナ粉末にロジウム化合物とジルコニウム化合物を分散担
持し、ロジウムとジルコニアを活性アルミナ上に固定せ
しめ、これを水性スラリー化せしめえられるスラリーを
前記コーティング処理した該担体に追加コーティングす
ることを特徴とする一体構造1排ガス浄化用触媒の製造
方法。(2) At least one platinum group element compound is dispersed and supported on activated alumina powder, the platinum group element is fixed on the activated alumina, and this is further formed into an aqueous slurry with cerium hydroxide powder, resulting in a slurry composition. A slurry is coated on a monolithic structure carrier, then a rhodium compound and a zirconium compound are dispersed and supported on activated alumina powder, rhodium and zirconia are fixed on the activated alumina, and this is made into an aqueous slurry. 1. A method for producing an exhaust gas purifying catalyst having an integrated structure, characterized in that the carrier is additionally coated.
(3)製造工程の最後の担持工程で担持されるロジウム
の量が全ロジウム担持量の50%以上であることを特徴
とする上記(1)または(2)記載の方法。(3) The method described in (1) or (2) above, wherein the amount of rhodium supported in the final supporting step of the manufacturing process is 50% or more of the total amount of rhodium supported.
(4)水酸化セリウム粉末の担持量がCeO,として5
〜100II/l−触媒体であることを特徴とする上記
(1)または(2)記載の方法。(4) The amount of supported cerium hydroxide powder is CeO, 5
~100II/l-catalyst, the method described in (1) or (2) above.
(5)水酸化セリウム粉末が一次粒子で実質的に0.1
〜0.8ミクロンの粒径かつ二次粒子で実質的に0.3
〜20ミクロン粒径を有する範囲のものであシ、しかも
40重量%以下の含水量を有するものであることを特徴
とする上記(1)、(2)または(4)記載の方法。(5) Cerium hydroxide powder is a primary particle with substantially 0.1
~0.8 micron particle size and substantially 0.3 secondary particles
The method according to (1), (2) or (4) above, characterized in that the particle size is in the range of -20 microns and has a water content of 40% by weight or less.
(6)水酸化セリウムと共にランタン化合物をその酸化
物合計(CeO2+ La201 )に対しLa103
として30重量%以下の量で使用することを特徴とする
上記(1)、(2)、(4)または(5)記載の方法。(6) La103 of lanthanum compound together with cerium hydroxide to its total oxide (CeO2+ La201)
The method according to (1), (2), (4) or (5) above, wherein the method is used in an amount of 30% by weight or less.
(7)活性アルミナ粉末にロジウムを分散担持する際に
用いられるジルコニウム化合物が、その酸化物(Z’r
02 )としての担持量を0〜10g/13−触媒体の
範囲とせしめられることを特徴とする上記(1)、(2
)または(3)記載の方法。(7) The zirconium compound used to disperse and support rhodium on activated alumina powder is
(1) and (2) above, characterized in that the supported amount as 02) is in the range of 0 to 10 g/13-catalyst body.
) or the method described in (3).
セリウム化合物として水酸化セリウムを用いうろことは
公知であり、たとえば、
(1)特開昭57−87839号には、これが硝酸セリ
ウム等の他の化合物と同様に使用することができるとし
て列記されている。また、
(2)特開昭57−56041号には、担体にウオツシ
ュコーテイングし、かつパラジウムを担持、焼成したの
ち、セリウム塩水溶液または水酸化セリウムゾルを含浸
する方法が記載されている。Scales using cerium hydroxide as a cerium compound are well known; for example, (1) JP-A-57-87839 lists it as being able to be used in the same way as other compounds such as cerium nitrate. There is. (2) JP-A No. 57-56041 describes a method in which a carrier is wash-coated, palladium is supported, fired, and then impregnated with a cerium salt aqueous solution or cerium hydroxide sol.
しかしえられた触媒については、水酸化セリウムゾルを
使用したものとセリウム塩水溶液を含浸したものとがほ
ぼ同一活性を示す旨記載されているにすきない。さらに
、
(3)特開昭57−g9835号には活性アルミナの顆
粒を水に分散させた分散液にセリウムの水溶性塩を共存
させ、この中にアンモニア水を加えてアルミナの表面に
セリウムの水利酸化物を沈殿させ、可溶性塩を除去する
ことからなる方法が記載されている。しかしこの方法は
濾過、洗浄を必要としていて工程が複雑であり、かつえ
られる触媒は白金族元素が一旦形成された酸化セリウム
表層含有活性アルミナ上に担持されている点に特徴を有
するものである。However, with regard to the obtained catalysts, there is little evidence that the catalyst using cerium hydroxide sol and the catalyst impregnated with an aqueous cerium salt solution exhibit almost the same activity. Furthermore, (3) JP-A No. 57-g9835 discloses that a water-soluble salt of cerium is coexisting in a dispersion of activated alumina granules in water, and aqueous ammonia is added to the dispersion to coat the surface of the alumina with cerium. A process is described which consists of precipitating the aqueous oxides and removing the soluble salts. However, this method requires filtration and washing and is a complicated process, and the resulting catalyst is characterized in that the platinum group element is supported on activated alumina containing a cerium oxide surface layer once formed.
いずれにしろ、これらは本発明が特定する水酸化セリウ
ム粉未使用を開示するものではなく、またそれらの触媒
は活性において本発明の触媒より劣るものである。In any case, these do not disclose the unused cerium hydroxide powder specified by the present invention, and their catalysts are inferior in activity to the catalyst of the present invention.
以下、本発明の具体的態様について説明する。Hereinafter, specific embodiments of the present invention will be described.
本発明に使用される水酸化セリウムは粉末状であシ、と
くに粒子径が一次粒子の大きさが0、1〜0.8μ、好
ましくは0.1〜0.4μ、そして二次粒子の大きさが
0.3〜20μ、好ましくは0.3〜10μであるよう
な粒子径のものであることが望まれる。また水酸化セリ
ウムは40重量−以下の水分含有量のものが好ましい。The cerium hydroxide used in the present invention is in powder form, and particularly has a particle size of 0.1 to 0.8 μm for primary particles, preferably 0.1 to 0.4 μm, and a size of secondary particles. It is desired that the particle size is 0.3 to 20μ, preferably 0.3 to 10μ. The cerium hydroxide preferably has a water content of 40% by weight or less.
その理由は、水分含有量が多すぎるとベトついて取扱い
にくいこと、および粒度分布が細かくなシすぎること等
が挙げられる。水酸化セリウムの水分含有量は、その製
造時に脱水工程において所望値に:ントロールすること
ができる。完成触媒中のセリウム酸化物の含有量はCe
O2として5〜1001 / l−触媒体、好ましくは
20〜8 ’OI / l−触媒体とされる。また水酸
化セリウムの活性アルミナに対する配合量は、5〜60
重量%、好ましくは10〜50重量%の範囲である。The reasons include that if the water content is too high, it becomes sticky and difficult to handle, and the particle size distribution is too fine. The water content of cerium hydroxide can be controlled to a desired value in a dehydration step during its production. The content of cerium oxide in the finished catalyst is Ce
O2 is 5-1001/l-catalyst, preferably 20-8'OI/l-catalyst. In addition, the blending amount of cerium hydroxide to activated alumina is 5 to 60
% by weight, preferably in the range 10-50% by weight.
使用される水酸化セリウムは80%以上の純度のものが
好ましく、不純物としては酸化ランタン、酸化ネオジム
、酸化プラセオジム、酸化サマリウム等が含有されてい
てもよい。この水酸化セリウムに他の希土類元素、たと
えば酸化ランタンをさらに添加して使用することができ
るがその添加量は、Ce01とLagolとの合計量に
対しLa20Bとして30重量−以下にすべきであシ、
酸化ランタンがそれ以上多く含まれると、見られる触媒
の三元特性が悪くなる。The cerium hydroxide used preferably has a purity of 80% or more, and may contain impurities such as lanthanum oxide, neodymium oxide, praseodymium oxide, samarium oxide, etc. Other rare earth elements such as lanthanum oxide can be further added to this cerium hydroxide, but the amount added should be less than 30% by weight as La20B relative to the total amount of Ce01 and Lagol. ,
If more lanthanum oxide is contained, the observed ternary properties of the catalyst will deteriorate.
本発明において用いる活性アルミナとしては比表面積5
0〜180 trl/ Iの活性アルミナが好ましい。The activated alumina used in the present invention has a specific surface area of 5
Activated alumina of 0-180 trl/I is preferred.
水酸化アルミニウム、ベーマイトおよび凝ベーマイト状
態の水利アルミナもハニカム担体に担持したのち焼成し
て前記活性アルミナとなりうるものは使用可能である。Aluminum hydroxide, boehmite, and water-use alumina in the form of solidified boehmite can also be used if they can be supported on a honeycomb carrier and fired to become the activated alumina.
ただし、完成触媒中で1、δ、θ、χ、にまたはすの結
晶形のアルミナとなシうるものでなければならない。こ
れらのうち、とくに好ましいアルミナは、比表面積70
〜1eord/Iのrおよびδ結晶形の活性アルミナで
ある。アルミナは完成触媒g当り50〜200.9の間
の量で担持される。However, it must be compatible with alumina in the crystalline form of 1, δ, θ, χ, or nitric acid in the finished catalyst. Among these, particularly preferable alumina has a specific surface area of 70
˜1 eord/I activated alumina in r and δ crystal forms. Alumina is supported in an amount between 50 and 200.9 g of finished catalyst.
本発明方法による触媒の製造は、たとえば次のような工
程に従って行われる。活性アルミナに白金族元素の少な
くとも1種の金属、たとえば、白金(Pt)、パラジウ
ム(pd)の水溶性化合物を含浸させ、アルミナの表層
にこれら金属化金物を直接担持させ、その後たとえば乾
燥、焼成するか、湿式でヒドラジン等の還元剤で白金族
元素を還元して固定化した後、これに所定量の水酸化セ
リウム粉末および必要に応じてランタン化合物を添加し
、湿式微粉砕機を使用してコーテイング液を調製し、一
体構造型担体に担持させ、余分のコーテイング液をたと
えばエアブロ−によ〉吹き飛ばし、所定量の触媒成分を
担持させ、乾燥、焼成する。更に、活性アルミナにロジ
ウム(Rh)の水溶性化合物を含浸させ、アルミナの表
層にロジウム化合物を直接担持させる。なお必要に応じ
てロジウム化合物と −ともにジルコニウム化合物を
使用し、その後たとえば乾燥、焼成するか、湿式でヒド
ラジン等の還元剤でロジウムを還元して固定化した後、
湿式粉砕機を使用してコーテイング液を調製し前記コー
ティング処理した一体構造麗担体に担持させ、余分のコ
ーテイング液を吹き飛ばし、所定の触媒成分を担持させ
、乾燥、焼成して完成触媒とする。The catalyst is produced by the method of the present invention, for example, according to the following steps. Activated alumina is impregnated with a water-soluble compound of at least one metal of the platinum group elements, such as platinum (Pt) and palladium (PD), and these metallized metals are directly supported on the surface layer of the alumina, and then, for example, dried and calcined. Alternatively, after reducing and immobilizing the platinum group elements with a reducing agent such as hydrazine in a wet process, a predetermined amount of cerium hydroxide powder and, if necessary, a lanthanum compound are added to this, and a wet pulverizer is used. A coating liquid is prepared, supported on an integral structure carrier, excess coating liquid is blown off, for example, by air blowing, a predetermined amount of the catalyst component is supported, and then dried and calcined. Furthermore, activated alumina is impregnated with a water-soluble compound of rhodium (Rh), and the rhodium compound is directly supported on the surface layer of the alumina. If necessary, a zirconium compound may be used together with a rhodium compound, and then, for example, after drying and firing, or after reducing and fixing rhodium with a reducing agent such as hydrazine in a wet process,
A coating liquid is prepared using a wet pulverizer and supported on the coated monolithic carrier, the excess coating liquid is blown off, the desired catalyst components are supported, and the finished catalyst is dried and calcined.
従って本発明の製造方法の特徴は、活性アルミナ上に直
接白金族元素を担持させて白金族元素を高表面積を有す
るアルミナ上に有効に分散担持して後水酸化セリウムと
混合し、微粉砕して一体構造型担体にコーティングする
と白金族元素の近傍に多量に分散担持せしめられた酸化
セリウムが安定に酸素貯蔵能を有しているためA/Pが
リッチ側にあるとき酸化セリウムから酸素を放出し、N
Ox浄化能のみならずC01HCの浄化能を高め、逆に
A/Fがリーン側にあるときは酸化セリウムが雰囲気中
00.をと9込み、Co、HC浄化能のみならず、NO
x浄化能を向上させる触媒を与えるのである。Therefore, the feature of the production method of the present invention is that the platinum group elements are directly supported on activated alumina, the platinum group elements are effectively dispersed and supported on the alumina having a high surface area, and then mixed with cerium hydroxide and finely pulverized. When coated on a monolithic carrier, the cerium oxide dispersed in large amounts near the platinum group element has a stable oxygen storage ability, so when the A/P is on the rich side, the cerium oxide releases oxygen. N
It increases not only the Ox purification ability but also the CO1HC purification ability, and conversely, when the A/F is on the lean side, cerium oxide in the atmosphere increases the 00. Including Co, HC purification ability as well as NO
It provides a catalyst that improves x purification ability.
本発明においては、この酸化−還元状態をくシ返す際に
、セリウム源として水酸化セリウム粉末を使用すると硝
酸セリウムや水酸化セリウムゾルでの担持の場合よシや
や分散度を粗くすることができ、しかも所定の粒度の酸
化セリウムの形で分散されているため、酸化セリウムが
高温に曝されても粒子成長が殆んどなく、安定してその
性能を維持し発揮するものと考えられる。In the present invention, when reversing this oxidation-reduction state, if cerium hydroxide powder is used as a cerium source, the dispersity can be made slightly coarser than when supported with cerium nitrate or cerium hydroxide sol. Moreover, since it is dispersed in the form of cerium oxide with a predetermined particle size, there is almost no particle growth even when cerium oxide is exposed to high temperatures, and it is thought that it stably maintains and exhibits its performance.
なお、一体構造型担体に担持したのち、特にロジウムの
使用量が少ない場合にはロジウムを有効に働かすため、
一旦水酸化セリウムを、活性アルミナ゛に固定した白金
族元素と共に一体構造型担体に担持したのち、さらにロ
ジウムを活性アルミナ上に有効に分散担持したスラリー
を一体構造型担体の表層部分に担持する方法が望ましい
。たとえば活性アルミナにptおよび/またはPdを担
持固定させたのち、水酸化セリウムと共に微粉砕してス
ラリー化し、これを一体構造型担体にコーティングして
焼成し九゛触媒組成物の表面に、さらに活性アルミナに
Rhおよび必要に応じてジルコニウムを担持固定化させ
た粉末の水性スラリーを追加コーティングし焼成した触
媒組成物はRhが表面近傍に分布することによシ、少量
担持されるRhがとくに有効に排ガス浄化活性に役立つ
ことになる。In addition, in order to make rhodium work effectively after being supported on a monolithic carrier, especially when the amount of rhodium used is small,
A method in which cerium hydroxide is once supported on a monolithic carrier together with a platinum group element fixed on activated alumina, and then a slurry in which rhodium is effectively dispersed and supported on the activated alumina is supported on the surface layer of the monolithic carrier. is desirable. For example, after supporting and fixing PT and/or Pd on activated alumina, it is finely pulverized with cerium hydroxide to form a slurry, and this is coated on a monolithic structure carrier and fired to further activate the active alumina. The catalyst composition is made by additionally coating alumina with an aqueous powder slurry in which Rh and, if necessary, zirconium are supported and fixed, and then calcined.Because Rh is distributed near the surface, a small amount of Rh supported is particularly effective. This will help in exhaust gas purification activity.
この場合、このRhを表層近傍に担持する方法において
、触媒が特に耐熱性を要求される時は、耐熱助剤として
知られているジルコニウムを添加すると、さらに有効で
あることが知見された。In this case, in the method of supporting Rh near the surface layer, it has been found that when the catalyst is particularly required to have heat resistance, it is more effective to add zirconium, which is known as a heat resistance aid.
本発明に用いる白金族金属はロジウムを必須とし、また
白金および/lたはパラジウムを使用するが白金族金属
の使用量はそれぞれ触媒1!当シ0.1〜5fIの間で
使われ、Rhとptおよび/またはPdの比は1:10
0から1=1の間で使うことができる。The platinum group metal used in the present invention is essentially rhodium, and platinum and /l or palladium are used, but the amount of each platinum group metal used is 1! The ratio of Rh to pt and/or Pd is 1:10.
It can be used between 0 and 1=1.
本発明の製造方法において、乾燥は200℃以下で、焼
成は200〜900℃の間で実施されるが、焼成は好ま
しくは400〜800℃の間で行なう。In the manufacturing method of the present invention, drying is carried out at 200°C or lower, and baking is carried out between 200 and 900°C, preferably between 400 and 800°C.
本発明において使用される一体構造を有するハニカム担
体としては通常セラミックハニカム担体と称されるもの
であればよく、とくにコージェライト、ムライト、αア
ルミナ、ジルコニア、チタニア、リン酸チタン、アルミ
ニウムチタネート、ペタライト、スポジュメン、アルミ
ノシリケート、珪酸マグネシウムなどを材料とするハニ
カム担体が好ましく、中でもコージェライト質のものが
とくに内燃機関用として好ましい。その他ステンレス製
またはフエクラロイなどの酸化抵抗性の耐熱金属を用い
て一体構造体としたものも使用される。これらモノリス
担体は、押出成型法や、シート状素子を巻き固める方法
で製造されたもので、そのガス通過口(セル型状)も6
角、4角、3角さらにコルゲージ゛ヨン型のいずれでも
採用しうる。七々密度(セル数/単位断面積)は150
〜600セル/平方インチであれば十分に使用可能で好
結果を与える。The honeycomb carrier having an integral structure used in the present invention may be one commonly called a ceramic honeycomb carrier, and in particular, cordierite, mullite, alpha alumina, zirconia, titania, titanium phosphate, aluminum titanate, petalite, Honeycomb carriers made of materials such as spodumene, aluminosilicate, and magnesium silicate are preferred, and among them, cordierite carriers are particularly preferred for use in internal combustion engines. In addition, a unitary structure made of oxidation-resistant heat-resistant metal such as stainless steel or FeClalloy is also used. These monolith carriers are manufactured by extrusion molding or by rolling and compacting sheet-like elements, and their gas passage ports (cell-shaped) also have 6
Square, four-sided, triangular, and corrugated-ylon types can be adopted. Nanada density (number of cells/unit cross-sectional area) is 150
~600 cells/square inch is fully usable and gives good results.
以下実施例にて本発明を更に詳細に説明するが、本発明
はこれら実施例のみに限定されるものでないことは言う
までもない。The present invention will be explained in more detail with reference to Examples below, but it goes without saying that the present invention is not limited only to these Examples.
実施例1
市販コージェライト質モノリス担体(NGK社製)を用
いて、触媒を調製した。モノリス担体は、断面1インチ
平方当り約300個のガス流通セルを有し、外径33
tnl、長さ76fiLの円筒状に切ったもので約65
−の体積を有するものである。Example 1 A catalyst was prepared using a commercially available cordierite monolith carrier (manufactured by NGK). The monolithic carrier has approximately 300 gas flow cells per square inch of cross-section and has an outer diameter of 33
tnl, cut into a cylindrical shape with a length of 76 fiL, approximately 65
It has a volume of -.
ジニトロ・ジアミノ白金(Pi(NHs)t(Not)
z )の硝酸水溶液(Pt含有量1o ol/l )
s omlに水を加え500−とした。この水溶液に表
面積1201i / i 、平均粒径50μの活性アル
ミナ粉末690.1i+を撹拌しながら加え、充分に混
合した後、150″CX5時間乾燥し、さらに電気炉で
2時間で600℃まで昇温し、この温度で2時間焼成を
続け、しかる後徐々に冷却して炉から取出した。Dinitro-diaminoplatinum (Pi(NHs)t(Not)
z ) nitric acid aqueous solution (Pt content 1o ol/l)
Water was added to soml to make it 500-. Activated alumina powder 690.1i+ with a surface area of 1201i/i and an average particle size of 50μ was added to this aqueous solution with stirring, and after thorough mixing, it was dried at 150″C for 5 hours, and then heated to 600°C in 2 hours in an electric furnace. Firing was continued at this temperature for 2 hours, after which it was gradually cooled and taken out from the furnace.
一次粒子が0.2〜0.3μの範囲、二次粒子が1〜6
μの範囲の含水水酸化セリウム(Ce(OH)4・4.
3 H,0)の粉末664Iと上記焼成物を混合し、希
硝酸水と共にポール・ミルで30時時間式粉砕しコーテ
ィング用スラリーを調製した。Primary particles are in the range of 0.2 to 0.3μ, secondary particles are in the range of 1 to 6
Hydrous cerium hydroxide (Ce(OH)) in the μ range 4.4.
3H,0) powder 664I and the above baked product were mixed and milled together with dilute nitric acid water in a Pall mill for 30 hours to prepare a coating slurry.
このコーティング用スラリーに前記モノリス担体を浸漬
し、その後スラリーよシ取出し、セル内の過剰スラリー
を圧縮空気でブローして、全てのセルの目詰シを除去し
た。この触媒を140℃×5時間乾燥器で乾燥し、引続
き電気炉で600℃×2時間焼成した。The monolithic carrier was immersed in this coating slurry, the slurry was then taken out, and excess slurry in the cells was blown away with compressed air to remove clogging from all cells. This catalyst was dried in a dryer at 140°C for 5 hours, and then calcined in an electric furnace at 600°C for 2 hours.
一方、硝酸ロジウム水溶液〔Rh (NO3) ・n
Hz O)液に前記と同様の活性アルミナ粉末4.00
gを撹拌しながら加え、充分に混合した後、150℃×
5時間乾燥し、さらに電気炉で600℃×2時間焼成し
、徐々に冷却して炉から取出した。On the other hand, rhodium nitrate aqueous solution [Rh (NO3) ・n
Hz O) Add activated alumina powder 4.00% as above to the liquid.
Add g while stirring, mix well, and heat to 150℃
It was dried for 5 hours, then fired in an electric furnace at 600°C for 2 hours, gradually cooled, and taken out from the furnace.
この焼成物を希硝酸水と共にポール・ミルで湿式粉砕し
コーティング用スラリーを調製した。This fired product was wet-milled with dilute nitric acid water in a Pall mill to prepare a coating slurry.
このコーティング用スラリーに前記ウォッシュ・コート
した触媒を浸漬し、その後スラリーより取出し、圧縮空
気でブローした。この触媒を140℃×5時間乾燥器で
乾燥し、完成触媒とした。なお、この触媒のコーティン
グ兼を測定したところX5OI//−触媒であった。そ
の担持量に対する重量比率はほぼAJ t Os/ C
eOx −109/4Gであった。The wash-coated catalyst was immersed in this coating slurry, then taken out from the slurry and blown with compressed air. This catalyst was dried in a dryer at 140° C. for 5 hours to obtain a finished catalyst. In addition, when the coating content of this catalyst was measured, it was found to be an X5OI//- catalyst. The weight ratio to the supported amount is approximately AJ t Os/C
eOx -109/4G.
白金、ロジウムについてはPt = 0.8 Ji’
/ l−触媒、Rh = 0.08 g/ l−触媒そ
れぞれ担持していた〔以下コノ担持量比率をAJ20s
/ CaO2/ P t/Rh −109/4010
.810.08 (1/l−触媒)と表現する。〕。For platinum and rhodium, Pt = 0.8 Ji'
/ l-catalyst and Rh = 0.08 g/l-catalyst were supported respectively [hereinafter, the ratio of supported amount is referred to as AJ20s
/CaO2/Pt/Rh-109/4010
.. Expressed as 810.08 (1/l-catalyst). ].
比較例1
セリア源として水酸化セリウムのかわりに硝酸セリウム
を使用した以外は実施例1とほぼ同様の手法で完成触媒
を調製した。Comparative Example 1 A finished catalyst was prepared in substantially the same manner as in Example 1, except that cerium nitrate was used instead of cerium hydroxide as a ceria source.
即ち、硝酸セリウム(Ce(NOx)s −6H,O)
1010Jに水300ggを加え水溶液とした。さら
にジニトロ・ジアミノ白金の硝酸水溶液(Pt含有量t
oo、@/A?)someを加え混合した。この水、溶
液に実施例1で用いたのと同じ活性アルミナ粉末690
gを加え充分に混合した後、150°Cで乾燥し、さら
に600℃×2時間焼成した。That is, cerium nitrate (Ce(NOx)s -6H,O)
1010J was added with 300 gg of water to make an aqueous solution. Furthermore, a nitric acid aqueous solution of dinitro-diaminoplatinum (Pt content t
oo, @/A? ) and mixed. The same activated alumina powder 690 used in Example 1 was added to this water and solution.
After adding g and thoroughly mixing, the mixture was dried at 150°C and further calcined at 600°C for 2 hours.
この焼成物を希硝酸水と共にポール・ミルで粉砕し、コ
ーティング用スラリーとした。以下、実施例1と全く同
じ手法で調製し、完成触媒としだ。担持量比率AA!
tos/ CeO2/ P t / Rh = 109
/4 olo、slo、o s (g/g−触媒)実施
例2
実施例1とほぼ同様な手法で組成の異る触媒を調製した
。実施例1と異る点は、まず貴金属源としてはジニトロ
・ジアミノ白金のかわりに、塩化白金酸(H2pt C
4)の水溶液を用いて690Iの活性アルミナ上に担持
した。さらにボールミル粉砕前に実施例1で用いたのと
同じ含水水酸化セリウム[: Ce(OH)4−4.3
a、o)の粉末5301と同時に含水水酸化ランタン
(La(OH)s ・2.2HzO)の粉末g3gを混
合してコーティング原料とした。以下実施例1と同じ手
法によりウォッシュ・コートした。さらに2段目ウォッ
シュ・コート原料中のロジウム源として硝酸ロジウム水
溶液のかわりに、塩化ロジウム(RhC1s)の水溶液
を用いて、以下実施例1と同じ手法で所定量担持し、乾
燥して完成触媒とした。担持量比率klxos / C
eO2/ La203 / P t / Rh = 1
09 / 32 / 810、slo、o s (g/
l−触媒)実施例3
実施例1と同様な手法で貴金属組成および重金属組成の
異る触媒を調製した。実施例1と異る点は、まず貴金属
源として白金のかわシにパラジウムを担持した触媒を調
製した。即ち、ジニトロ・ジアミノ白金のかわシに硝酸
バラジウム(Pd(NOs)z 〕の硝酸水溶液を用い
て、実施例1と同じようにウォッシュ・コートした。さ
らにロジウムを活性アルミナに担持する工程で硝酸ジル
コニル(Zr0(NOx)z)を添加した以外は、実施
例1と同様の手法により完成触媒を調製した。担持量比
率M、o2/CeO2/ ZrO,/ Pd/ Rh
−104/401510.810.0s(1/l−触媒
)実施例4
実施例1と同様な手法で貴金属組成のみ異る触媒を調製
した。即ち、ジニトロ・ジアミノ白金のかわpにジニト
ロ・ジアミノ白金と硝酸パラジウムの混合溶液を用いて
実施例1と同様な手法により完成触媒を調製した。担持
量比本人g0s/CeO,/Pt/Pd/Rh −1
09/4 olo、s 710、2310.Os (g
/l−触媒)実施例5
実施例1から実施例4までの触媒と比較例1の触媒をエ
ンジン排ガスを用いて三元特性評価実験およびライト・
オフ特性評価実験を行った。This fired product was ground with dilute nitric acid water in a Pall mill to obtain a slurry for coating. Hereinafter, a finished catalyst was prepared in exactly the same manner as in Example 1. Supported amount ratio AA!
tos/CeO2/Pt/Rh=109
/4 olo, slo, os (g/g-catalyst) Example 2 Catalysts with different compositions were prepared in substantially the same manner as in Example 1. The difference from Example 1 is that instead of dinitrodiaminoplatinum, chloroplatinic acid (H2pt C
The aqueous solution of 4) was used to support 690I on activated alumina. Furthermore, before ball milling, the same hydrous cerium hydroxide [: Ce(OH)4-4.3 as used in Example 1]
At the same time, 3 g of hydrous lanthanum hydroxide (La(OH)s 2.2 HzO) powder was mixed with the powder 5301 of a and o) to prepare a coating raw material. Thereafter, wash coating was performed using the same method as in Example 1. Furthermore, as a rhodium source in the second-stage wash coat raw material, an aqueous solution of rhodium chloride (RhC1s) was used instead of an aqueous solution of rhodium nitrate, and a predetermined amount was supported in the same manner as in Example 1, and the finished catalyst was dried. did. Supported amount ratio klxos/C
eO2/La203/Pt/Rh=1
09/32/810, slo, o s (g/
l-Catalyst) Example 3 Catalysts having different noble metal compositions and heavy metal compositions were prepared in the same manner as in Example 1. The difference from Example 1 is that first, a catalyst was prepared in which palladium was supported on a platinum slag as a noble metal source. That is, dinitro-diaminoplatinum was wash-coated using a nitric acid aqueous solution of palladium nitrate (Pd(NOs)z) in the same manner as in Example 1. In addition, in the process of supporting rhodium on activated alumina, zirconyl nitrate was applied. A finished catalyst was prepared in the same manner as in Example 1 except that (Zr0(NOx)z) was added.Supported amount ratio M, o2/CeO2/ZrO,/Pd/Rh
-104/401510.810.0s (1/l-catalyst) Example 4 A catalyst different only in noble metal composition was prepared in the same manner as in Example 1. That is, a finished catalyst was prepared in the same manner as in Example 1 using a mixed solution of dinitro-diamino platinum and palladium nitrate in a dinitro-diamino platinum solution. Supported amount ratio individual g0s/CeO, /Pt/Pd/Rh -1
09/4 olo, s 710, 2310. Os (g
/l-catalyst) Example 5 The catalysts of Examples 1 to 4 and the catalyst of Comparative Example 1 were subjected to three-way characteristic evaluation experiments and light
An off-characteristic evaluation experiment was conducted.
本実験で使用されたエンジンは市販の電子制御式4気筒
tsooccである。三元特性評価実験は、実際のクロ
ーズトループ式エンジンのA/F状態をモデル化した方
法である。強制的に1.0Hzで±o、 s A/F単
位で振動させ、その時の中心を人/F=15.1から1
4.1まで6分間で変化させてその時のC01HCおよ
びNOx成分の浄化率を測定し、たて軸に3成分の浄化
率を横軸にA/Fの中心点をプロットして作成された三
元触媒特性図に基いて性能を比較した。すなわち、CO
転化率曲線とNOx浄化率曲線の交点〔クロス・オーバ
ー・ポイント(COP)と呼ぶ〕の高さが高くかつ80
%以上の転化率・浄化率を同時に達成しうるA/F幅(
80%ウィンドウ幅)が大きいものが良好な触媒という
ことになる。(評価結果を第1表に示した。)
一方、ライト・オフ特性評価実験では、強制的に1.0
HzでA/Fを14.60を中心にして14.10か
ら15.10までの間で振動させ、排ガス温度を室温か
ら450℃まで約り0℃/分で昇温し、その時のC01
HCおよびNOx成分の浄化率を測定し、横軸に触媒入
口温度を、たて軸に3成分の浄化率をプロットし、でき
た図より三元触媒の低温活性性能を比較した。すなわち
、良好な触媒3成分共に50チ転化率および80%転化
率に達する温度(それぞれT、。、T、。とじて第1表
に示す)が低い程低温活性が優れた触媒であると評価さ
れる。The engine used in this experiment was a commercially available electronically controlled 4-cylinder TSOOCC. The ternary characteristic evaluation experiment is a method of modeling the A/F state of an actual closed-loop engine. Forcibly vibrate at 1.0Hz in ±o, s A/F units, and the center at that time is from person/F = 15.1 to 1
The purification rate of CO1HC and NOx components at that time was measured by changing it to 4.1 in 6 minutes, and the purification rate of the three components was plotted on the vertical axis, and the center point of the A/F was plotted on the horizontal axis. Performance was compared based on the original catalyst characteristic diagram. That is, CO
The height of the intersection of the conversion rate curve and the NOx purification rate curve [called the crossover point (COP)] is high and 80%
A/F width (
A catalyst with a large (80% window width) is a good catalyst. (The evaluation results are shown in Table 1.) On the other hand, in the light-off characteristic evaluation experiment, 1.0
The A/F was oscillated between 14.10 and 15.10 with 14.60 as the center, and the exhaust gas temperature was raised from room temperature to 450°C at a rate of 0°C/min.
The purification rates of HC and NOx components were measured, and the catalyst inlet temperature was plotted on the horizontal axis, and the purification rates of the three components were plotted on the vertical axis, and the low-temperature activity performance of the three-way catalyst was compared from the resulting diagram. In other words, the lower the temperature at which the three good catalyst components reach 50% conversion and 80% conversion (T, ., T, ., respectively), the better the catalyst has excellent low-temperature activity. be done.
実施例6
実施例5で初期活性を評価した触媒をエンジン台上試験
装置により、耐久走行にかけた。使用されたエンジンは
市販の電子制御式8気筒4400eCで、耐久操作方法
としてプログラムセッター使用によるモード運転法を採
用した。即ち、60秒間エンジン回転数2800 rp
m Xブースト圧(−220mtxHg )で定常走行
し、6秒間スロットルを戻し燃料を切る。6秒後にエン
ジンの回転数は約180Orpmとなる。この減速走行
の時に入口酸素濃度が約18チとなり、触媒を急速に劣
化させる。触媒にマルチコンバーターに充填して、耐久
試験を行った。定常走行時において触媒出口温度750
℃、空間速度(S、V、)が約29J)、000 hr
−1(8TP ’)、人/Fが14.60となる条件の
もとに、100時間エージングした。Example 6 The catalyst whose initial activity was evaluated in Example 5 was subjected to endurance running using an engine bench test device. The engine used was a commercially available electronically controlled 8-cylinder 4400eC engine, and a mode operation method using a program setter was adopted as a durable operation method. That is, engine speed 2800 rp for 60 seconds
Drive steadily at mX boost pressure (-220mtxHg), then return the throttle for 6 seconds and turn off the fuel. After 6 seconds, the engine speed becomes approximately 180 rpm. During this deceleration running, the inlet oxygen concentration reaches approximately 18 degrees, causing rapid deterioration of the catalyst. A durability test was conducted by filling the catalyst into a multi-converter. Catalyst outlet temperature 750 during steady running
°C, space velocity (S, V, ) is approximately 29 J), 000 hr
The sample was aged for 100 hours under conditions such that -1 (8TP') and Person/F was 14.60.
評価は実施例5におけると同様の操作により、三元特性
およびライト・オフ特性を測定した。For evaluation, ternary characteristics and light-off characteristics were measured using the same operations as in Example 5.
評価結果を第1表に示す。本発明の触媒は、三元特性に
おいていぜん高い水準のCOPと有効なウィンドウを保
有している。さらにライト・オフ特性においても、本発
明触媒はTSo s T2Oが低温であり比較例1より
も優れている。The evaluation results are shown in Table 1. The catalyst of the present invention possesses the highest level of COP and effective window in ternary properties. Furthermore, in terms of light-off characteristics, the catalyst of the present invention is superior to Comparative Example 1 since TSo s T2O is at a low temperature.
Claims (7)
の化合物を分散担持し、当該白金族元素を活性アルミナ
上に固定せしめ、さらにこれを水酸化セリウム粉末と共
に水性スラリー化せしめ、えられたスラリー組成物を一
体構造型担体にコーティング処理し、その後活性アルミ
ナ粉末にロジウム化合物を分散担持し、ロジウムを活性
アルミナ上に固定せしめたのち、水性スラリー化せしめ
、えられたスラリーを前記コーティング処理した該担体
に追加コーティングすることを特徴とする一体構造型排
ガス浄化用触媒の製造方法。(1) At least one platinum group element compound is dispersed and supported on activated alumina powder, the platinum group element is fixed on the activated alumina, and this is further formed into an aqueous slurry with cerium hydroxide powder, resulting in a slurry composition. After that, a rhodium compound is dispersed and supported on activated alumina powder, rhodium is fixed on the activated alumina, and then an aqueous slurry is formed, and the resulting slurry is coated on the coated support. A method for producing an integrated structure exhaust gas purifying catalyst characterized by additionally coating the catalyst.
の化合物を分散担持し、当該白金族元素を活性アルミナ
上に固定せしめ、さらにこれを水酸化セリウム粉末と共
に水性スラリー化せしめ、えられたスラリー組成物を一
体構造型担体にコーティング処理し、その後活性アルミ
ナ粉末にロジウム化合物とジルコニウム化合物を分散担
持し、ロジウムとジルコニアを活性アルミナ上に固定せ
しめ、これを水性スラリー化せしめてえられたスラリー
を前記コーティング処理した該担体に追加コーティング
することを特徴とする一体構造型排ガス浄化用触媒の製
造方法。(2) At least one platinum group element compound is dispersed and supported on activated alumina powder, the platinum group element is fixed on the activated alumina, and this is further formed into an aqueous slurry with cerium hydroxide powder, resulting in a slurry composition. After that, a rhodium compound and a zirconium compound are dispersed and supported on activated alumina powder, rhodium and zirconia are fixed on the activated alumina, and this is made into an aqueous slurry. A method for producing an integrated structure exhaust gas purifying catalyst, which comprises additionally coating the coated carrier.
の量が全ロジウム担持量の50%以上であることを特徴
とする特許請求の範囲(1)または(2)記載の方法。(3) The method according to claim (1) or (2), wherein the amount of rhodium supported in the final supporting step of the manufacturing process is 50% or more of the total amount of rhodium supported.
5〜100g/l−触媒体であることを特徴とする特許
請求の範囲(1)または(2)記載の方法。(4) The method according to claim (1) or (2), characterized in that the amount of cerium hydroxide powder supported is 5 to 100 g/l of CeO_2 catalyst.
〜0.8ミクロンの粒径かつ二次粒子で実質的に0.3
〜20ミクロンの粒径を有する範囲のものであり、しか
も40重量%以下の含水量を有するものであることを特
徴とする特許請求の範囲(1)、(2)または(4)記
載の方法。(5) Cerium hydroxide powder is a primary particle with substantially 0.1
~0.8 micron particle size and substantially 0.3 secondary particles
The method according to claim (1), (2) or (4), characterized in that the particle size is in the range of ~20 microns and has a water content of 40% by weight or less. .
物合計(CeO_2+La_2O_3)に対しLa_2
O_3として30重量%以下の量で使用することを特徴
とする特許請求の範囲(1)、(2)、(4)または(
5)記載の方法。(6) La_2 for the total oxide (CeO_2+La_2O_3) of lanthanum compound together with cerium hydroxide
Claims (1), (2), (4) or (
5) The method described.
用いられるジルコニウム化合物がその酸化物(ZrO_
2)としての担持量を0〜10g/l−触媒体の範囲と
せしめられることを特徴とする特許請求の範囲(1)、
(2)または(3)記載の方法。(7) The zirconium compound used when rhodium is dispersed and supported on activated alumina powder is its oxide (ZrO_
Claim (1) characterized in that the supported amount as 2) is made to be in the range of 0 to 10 g/l-catalyst body,
The method described in (2) or (3).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60062060A JPS61222539A (en) | 1985-03-28 | 1985-03-28 | Preparation of monolithic type exhaust gas purifying catalyst |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60062060A JPS61222539A (en) | 1985-03-28 | 1985-03-28 | Preparation of monolithic type exhaust gas purifying catalyst |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS61222539A true JPS61222539A (en) | 1986-10-03 |
JPH052373B2 JPH052373B2 (en) | 1993-01-12 |
Family
ID=13189204
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60062060A Granted JPS61222539A (en) | 1985-03-28 | 1985-03-28 | Preparation of monolithic type exhaust gas purifying catalyst |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS61222539A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990014887A1 (en) * | 1989-06-09 | 1990-12-13 | N.E. Chemcat Corporation | Exhaust gas purifying catalyst excellent in thermal resistance and method of production thereof |
JP2001286764A (en) * | 2000-04-05 | 2001-10-16 | Mitsui Mining & Smelting Co Ltd | Exhaust gas cleaning catalyst and manufacture thereof |
JP2005103410A (en) * | 2003-09-30 | 2005-04-21 | Tokyo Roki Co Ltd | Exhaust gas cleaning catalyst |
JP2007007496A (en) * | 2005-06-28 | 2007-01-18 | Cataler Corp | Method for adjusting viscosity of slurry and coating slurry for catalyst |
-
1985
- 1985-03-28 JP JP60062060A patent/JPS61222539A/en active Granted
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990014887A1 (en) * | 1989-06-09 | 1990-12-13 | N.E. Chemcat Corporation | Exhaust gas purifying catalyst excellent in thermal resistance and method of production thereof |
US5147842A (en) * | 1989-06-09 | 1992-09-15 | N.E. Chemcat Corporation | Exhaust gas-purifying catalyst and process for preparation thereof |
US5200384A (en) * | 1989-06-09 | 1993-04-06 | N.E Chemcat Corporation | Exhaust gas-purifying catalyst excellent in heat resistance and process for preparation thereof |
JP2001286764A (en) * | 2000-04-05 | 2001-10-16 | Mitsui Mining & Smelting Co Ltd | Exhaust gas cleaning catalyst and manufacture thereof |
JP2005103410A (en) * | 2003-09-30 | 2005-04-21 | Tokyo Roki Co Ltd | Exhaust gas cleaning catalyst |
JP2007007496A (en) * | 2005-06-28 | 2007-01-18 | Cataler Corp | Method for adjusting viscosity of slurry and coating slurry for catalyst |
Also Published As
Publication number | Publication date |
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JPH052373B2 (en) | 1993-01-12 |
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