JPH02102735A - Catalyst for purification of exhaust gas - Google Patents
Catalyst for purification of exhaust gasInfo
- Publication number
- JPH02102735A JPH02102735A JP63255466A JP25546688A JPH02102735A JP H02102735 A JPH02102735 A JP H02102735A JP 63255466 A JP63255466 A JP 63255466A JP 25546688 A JP25546688 A JP 25546688A JP H02102735 A JPH02102735 A JP H02102735A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- coprecipitate
- exhaust gas
- slurry
- carrier
- 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.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 46
- 238000000746 purification Methods 0.000 title abstract description 6
- 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 13
- 239000002131 composite material Substances 0.000 claims description 9
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 abstract description 40
- 229910052763 palladium Inorganic materials 0.000 abstract description 20
- 229910052703 rhodium Inorganic materials 0.000 abstract description 18
- 229910052779 Neodymium Inorganic materials 0.000 abstract description 12
- 239000002002 slurry Substances 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 6
- 229910052746 lanthanum Inorganic materials 0.000 abstract description 5
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 abstract description 4
- 235000012501 ammonium carbonate Nutrition 0.000 abstract description 4
- 239000001099 ammonium carbonate Substances 0.000 abstract description 4
- CFYGEIAZMVFFDE-UHFFFAOYSA-N neodymium(3+);trinitrate Chemical compound [Nd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O CFYGEIAZMVFFDE-UHFFFAOYSA-N 0.000 abstract description 4
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 abstract description 4
- 229910000510 noble metal Inorganic materials 0.000 abstract description 3
- 239000003153 chemical reaction reagent Substances 0.000 abstract description 2
- 239000002699 waste material Substances 0.000 abstract description 2
- 239000010948 rhodium Substances 0.000 description 31
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 15
- 239000007789 gas Substances 0.000 description 10
- 239000000203 mixture Substances 0.000 description 7
- 150000001875 compounds Chemical class 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910052772 Samarium Inorganic materials 0.000 description 5
- 239000011259 mixed solution Substances 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- 230000000052 comparative effect Effects 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
- 239000000243 solution Substances 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium oxide Inorganic materials [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 229910002090 carbon oxide Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 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 2
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000010970 precious metal Substances 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
- 238000003756 stirring Methods 0.000 description 2
- 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
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 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
- 238000005516 engineering process Methods 0.000 description 1
- 230000009422 growth inhibiting effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は排気ガス浄化用触媒、更に詳しくは触媒成分と
してＰｄ （パラジウム）及びＲｈ （ロジウム）を含
む排気ガス浄化用触媒に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an exhaust gas purifying catalyst, and more particularly to an exhaust gas purifying catalyst containing Pd (palladium) and Rh (rhodium) as catalyst components.
自動車等の内燃機関から排出される排気ガス中に含有さ
れる有害物質のうち、主なものは炭化水素（ＨＣ） 、
−酸化炭素（ＣＯ）及び窒素酸化物 （ＮＯｘ）の三成
分である。この三成分を一度に浄化処理できる触媒を三
元触媒と呼んでいる。Among the harmful substances contained in the exhaust gas emitted from internal combustion engines such as automobiles, the main ones are hydrocarbons (HC),
- Three components: carbon oxide (CO) and nitrogen oxide (NOx). A catalyst that can purify these three components at once is called a three-way catalyst.
三元触媒においては触媒成分として貴金属が使用されて
おり、例えばｐｔ （白金）やＰｄはＩＣ及びＣＯの酸
化に有効であり、又、ＲｈはＮＯｘの還元に有効である
。それ故、三元触媒としては（ｐｔ又はＰｄ） ／Ｒｈ
系触媒が用いられているが、近年、ｐｔよりも資源量及
び価格の点で有利なＰｄを用いたＰｄ／ Ｒｈ系触媒を
用いる試みがなされている。In three-way catalysts, noble metals are used as catalyst components, such as pt (platinum) and Pd, which are effective in oxidizing IC and CO, and Rh, which is effective in reducing NOx. Therefore, as a three-way catalyst, (pt or Pd) /Rh
However, in recent years, attempts have been made to use Pd/Rh based catalysts using Pd, which is more advantageous than PT in terms of resource quantity and price.
上記触媒において、Ｐｄは還元性雰囲気で粒成長し易く
、それ自体の表面積を減少させて活性を低下させる傾向
がある。又、ＰｄはＲｈの表面を覆ったり、これと合金
化し易く、触媒活性や耐久性の点で問題がある。In the above catalyst, Pd tends to grow grains in a reducing atmosphere, reducing its own surface area and decreasing its activity. Furthermore, Pd tends to cover the surface of Rh or form an alloy with it, which poses problems in terms of catalytic activity and durability.
とのＰｄ／ Ｒｈ系触媒における粒成長（シリンダ）を
抑制した触媒として、アルミナ等からなる触媒担体上に
触媒成分としてＰｄ、 Ｒｈに加えＮｄ（ネオジウム）
及び／又は Ｓｍ （サマリウム）を担持せしめてなる
排気ガス浄化用触媒が特開昭６２−５７６５１号公報に
開示されている。該触媒ではＮｄやＳｍがＰｄと複合酸
化物を作ることによりＰｄの粒成長を抑制するとされて
いる。As a catalyst that suppresses grain growth (cylinder) in a Pd/Rh based catalyst, Nd (neodymium) is added as a catalyst component to a catalyst carrier made of alumina etc. in addition to Pd and Rh.
and/or An exhaust gas purifying catalyst on which Sm (samarium) is supported is disclosed in JP-A-62-57651. In this catalyst, Nd and Sm are said to suppress the grain growth of Pd by forming a composite oxide with Pd.
しかし、この特開昭６０−１１４３４１号公報記載の排
気ガス浄化用触媒は、アルミナなどからなる触媒担体に
Ｎｄ及び／又はＳｍを添加し、その後Ｐｄ及びＲｈを担
持するものであるため、ＮｄやＳｍのところにＰｄを全
て担持できず、他のところに担持されたＰｄは粒成長し
易い。However, in the exhaust gas purifying catalyst described in JP-A-60-114341, Nd and/or Sm are added to a catalyst carrier made of alumina or the like, and then Pd and Rh are supported. Not all Pd can be supported on Sm, and Pd supported on other parts tends to grow grains.
本発明者らはこの点について鋭意研究を重ねた結果、最
近になってＲｈにはＮｄやＳ１１よりもＬａ（ランタン
）の方が効果が大きいこと並びにＮｄ２Ｏ３（酸化ネオ
ジウム）及びＬａ１ｅｓ （酸化ランタン）がそれぞれ
Ｐｄ及びＲｈの粒成長を抑制することを見い出し、この
知見に基づく新たな触媒を特願昭６３−１０２２９４号
にて提案している。As a result of extensive research by the present inventors on this point, we have recently found that La (lanthanum) has a greater effect on Rh than Nd or S11, and that Nd2O3 (neodymium oxide) and La1es (lanthanum oxide) It was discovered that Pd and Rh each inhibit grain growth, and based on this knowledge, a new catalyst was proposed in Japanese Patent Application No. 102294/1983.
該触媒はいわばＰｄ／ Ｒｈ系触媒の製造方法を工夫す
ることによりＰｄやＲｈの粒成長を更に良く抑制するよ
うにしたもので、予めＰｄを担持させたＮｄ！Ｏ３粉末
と予めＲｈを担持させたＬａｔｅａとを加えてアルミス
ラリーを調製し、それを担体にコートし、乾燥、焼成す
ることにより製造される触媒である。This catalyst, so to speak, is a product in which the grain growth of Pd and Rh is further suppressed by devising a manufacturing method for a Pd/Rh based catalyst, and Nd! This catalyst is produced by adding O3 powder and Latea on which Rh has been previously supported to prepare an aluminum slurry, coating the slurry on a carrier, drying, and firing.
ところでアルミナ担体にＮｄ、 Ｓｍを添加し、その後
Ｐｄ、 Ｒｈを担持させる前記従来の触媒では、Ｎｄ、
Ｓｍがアルミナと結び付き易い性質を有しているため
、ＰｄはＮｄ、 Ｓｍに結び付きにくいという問題があ
り、そして予めＰｄをＮｄＪｓに、 ＲｈをＬａｔｅａ
に担持させて製造される上記提案の触媒においても同様
の問題が残されていた。即ち、ＰｄやＲｈは全て複合酸
化物となり得ず、Ｎｄ、 ＬａによるＰｄ、 Ｒｈの粒
成長抑制能力が十分に発揮されないという問題があった
。By the way, in the conventional catalyst in which Nd and Sm are added to an alumina carrier and then Pd and Rh are supported, Nd,
Since Sm has the property of easily bonding with alumina, there is a problem that Pd is difficult to bond with Nd and Sm.
Similar problems remain in the above-mentioned proposed catalyst which is produced by supporting the catalyst. That is, Pd and Rh cannot all form composite oxides, and there is a problem in that the ability of Nd and La to suppress grain growth of Pd and Rh is not sufficiently exhibited.
本発明は上記問題を解決する目的でなされたものであり
、その解決しようとする課題は、資源的に少なく高価な
Ｐｄ、 Ｒｈ等の貴金属を有効に使用し、今まで以上に
活性及び耐久性を向上させた排気ガス浄化用触媒を提供
することである。The present invention was made for the purpose of solving the above-mentioned problem, and the problem to be solved is to effectively use precious metals such as Pd and Rh, which are scarce in terms of resources and expensive, to make them more active and durable than ever before. An object of the present invention is to provide a catalyst for purifying exhaust gas with improved performance.
［課題を解決するための手段］
そのための本発明の排気ガス浄化用触媒は、Ｐｄ−Ｎｄ
共沈物から生じたＰｄ−Ｎｄ複合酸化物とＲｈ−Ｌａ共
沈物から生じたＲｈ−Ｌａ複合酸化物が耐火性担体上の
アルミナコート層に含まれていることを特徴とする。[Means for Solving the Problems] To achieve this, the exhaust gas purifying catalyst of the present invention comprises Pd-Nd
It is characterized in that a Pd-Nd composite oxide produced from a coprecipitate and a Rh-La composite oxide produced from a Rh-La coprecipitate are contained in an alumina coat layer on a refractory carrier.
ここでＰｄ・Ｎｄ共沈物とは、易溶性のＰｄ化合物とＮ
ｄ化合物を溶かした溶解液に適当な試薬を加えることに
よりＰｄ及びＮｄが共に不溶性化合物となって沈殿した
ものを意味する。Ｒｈ−Ｌａ共沈物についても同様であ
る。Here, the Pd/Nd coprecipitate refers to easily soluble Pd compound and N
d refers to a compound in which both Pd and Nd become insoluble compounds and precipitate by adding an appropriate reagent to a solution containing the compound. The same applies to the Rh-La coprecipitate.
本発明の触媒は、例えば硝酸ネオジウムと硝酸パラジウ
ムの混合溶液に炭酸アンモニウム等の炭酸塩を加えて得
られるＮｄｇ （ｃｏｓｌ ｓとＰｄ （ＯＨ１，から
なるＰｄ−Ｎｄ共沈物と、例えば同様にして得られるＬ
ａｔ（ＣＯａ） ｓとＲｈ （ＯＨ）、からなるＬａ−
Ｒｈ共沈物をアルミナスラリーに加え、それを耐火性担
体にコートし、乾燥・焼成することにより製造すること
ができる。The catalyst of the present invention can be obtained by adding a carbonate such as ammonium carbonate to a mixed solution of neodymium nitrate and palladium nitrate, and a Pd-Nd coprecipitate consisting of Ndg (cosl s) and Pd (OH1), for example. Obtained L
La- consisting of at(COa)s and Rh(OH)
It can be produced by adding Rh coprecipitate to alumina slurry, coating it on a refractory carrier, drying and firing.
耐火性担体の材質は例えばコーディエライト、ムライト
、アルミナ、耐熱性金属等であってよい。その大きさや
形状は特に限定されない、形状としては例えばペレット
状又はハニカム状のモノリス担体等であってよい、コー
ディエライト質モノリス担体を用いるのが好ましい、な
お、前記スラリー中には他の成分例えば助触媒成分など
を加えてもよい。The material of the refractory carrier may be, for example, cordierite, mullite, alumina, heat-resistant metal, or the like. The size and shape are not particularly limited, and the shape may be, for example, a pellet-like or honeycomb-like monolith support. It is preferable to use a cordierite monolith support. Note that the slurry may contain other components such as A promoter component etc. may be added.
Ｐｄ−Ｎｄ共沈物およびＲｈ−Ｌａ共沈物はそれぞれ混
合溶液から作られるため、ＰｄとＮｄの並びにＲｈとＬ
ａの混合状態が非常に良く （より分子的レベルに近い
混合となり）、アルミナスラリーに加え混練してもそれ
らの混合物は細かい塊としてそれぞれ混ざる。このスラ
リーを担体にコートし焼成すると、ＰｄとＮｄ並びにＲ
ｈとＬａは混合状態がよいために共に容易に複合酸化物
に変る。こうしてＰｄ及びＲｈの粒成長がそれぞれＮｄ
及びＬａにより有効に抑制される。Pd-Nd coprecipitate and Rh-La coprecipitate are each made from a mixed solution, so Pd and Nd as well as Rh and L
The mixing state of a is very good (the mixture is closer to the molecular level), and even when added to the alumina slurry and kneaded, the mixture mixes as fine lumps. When this slurry is coated on a carrier and fired, Pd, Nd and R
Since h and La are in a good mixing state, both can be easily converted into a composite oxide. In this way, the grain growth of Pd and Rh is
and La.
以下の実施例及び比較例において本発明を更に詳細に説
明する。なお、本発明は下記実施例に限定されるもので
はない。The present invention will be explained in further detail in the following Examples and Comparative Examples. Note that the present invention is not limited to the following examples.
硝酸ネオジウム４３８ｇと、Ｐｄ重量でｌＯｇに相当す
る量の硝酸パラジウムを純水３βに溶かし、混合溶液Ａ
を調製した０次に炭酸アンモニウム２００ｇを純水ａｏ
ｏ ｇに溶かした水溶液を、上記混合溶液Ａに徐々に加
えていき、Ｎｄヨ（ＣＯ，）、やＰｄ （ＯＨ） ｚ等
からなる難水溶性化合物の混合物Ｃを調製した。438g of neodymium nitrate and palladium nitrate in an amount equivalent to 1Og in Pd weight were dissolved in pure water 3β to form a mixed solution A.
Add 200g of prepared ammonium carbonate to pure water ao
An aqueous solution dissolved in 0 g was gradually added to the above mixed solution A to prepare a mixture C of poorly water-soluble compounds consisting of Nd(CO,), Pd(OH), and the like.
一方、硝酸ランタン８７０ ｇと、Ｒｈ重量で１ｇ相当
する量の硝酸ロジウムを純水３εに溶かし、混合溶液Ｂ
を作り、これに上記と同様にして炭酸アンモニウム水溶
液を加え、 Ｌａｇ （ＧＯ３１ｘやＲｈ （ＯＨＭ、
等からなる難水溶性化合物の混合物りを調製した。On the other hand, dissolve 870 g of lanthanum nitrate and rhodium nitrate in an amount equivalent to 1 g in terms of Rh weight in pure water 3ε, and mix solution B.
To this, add ammonium carbonate aqueous solution in the same manner as above, and add Lag (GO31x, Rh (OHM,
A mixture of poorly water-soluble compounds was prepared.
別に、活性アルミナ粉末８７０ｇ、硝酸アルミニウム水
溶液（４０ｗｔ％） ２６０ｇ及び純水７８０ｇを混
練したものを作り、これに上記混合物Ｃ及びＤを加え撹
拌し、スラリー■を調製した。Separately, 870 g of activated alumina powder, 260 g of aluminum nitrate aqueous solution (40 wt%) and 780 g of pure water were kneaded, and the above mixtures C and D were added and stirred to prepare slurry (2).
このスラリー■にコーディエライト製モノリス担体用基
材（φ１０７ Ｘ Ｌ ７８）を１分間浸漬した後、引
き上げて余分な水分を飛ばし、 １００℃で１時間乾燥
後、７００℃で２時間焼成し、８５ｇコートした。この
ようにして、Ｐｄ−Ｎｄ共沈物とＲｈ−Ｌａ共沈物を用
いて製造された触媒Ｉを得た。A cordierite monolith carrier base material (φ107 XL 78) was immersed in this slurry ■ for 1 minute, then pulled out to remove excess moisture, dried at 100°C for 1 hour, and then fired at 700°C for 2 hours. 85g was coated. In this way, Catalyst I manufactured using a Pd-Nd coprecipitate and a Rh-La coprecipitate was obtained.
比較例１
活性アルミナ粉末１０００ ｇ、硝酸アルミニウム水溶
液（４０ｗｔ％） ３００ｇ、純水９００ ｇを混合
し、撹拌してスラリーＩＩを調製した。このスラリー１
１にコーディエライト質モノリス担体（φ １０７Ｘ
７８Ｌ ）を１分間浸漬した後、引き上げて余分な水分
を吹きとばし、 １００℃で１時間乾燥後、７００℃で
２時間焼成し６０ｇコートした。続いて、純水６２１．
８ｇに硝酸ランタン７５７．８ ｇ及び硝酸ネオジウム
７６７、１ ｇを溶かした混合溶液に上記コートした担
体を浸漬し、弓き上げ、余分な水分を吹きとばし、１０
０℃で１時間乾燥した後、７００℃で２時間焼成した。Comparative Example 1 1000 g of activated alumina powder, 300 g of aluminum nitrate aqueous solution (40 wt%), and 900 g of pure water were mixed and stirred to prepare slurry II. This slurry 1
Cordierite monolith carrier (φ 107X
78L) was immersed for 1 minute, then pulled out, excess moisture was blown off, dried at 100°C for 1 hour, and then baked at 700°C for 2 hours to coat 60g. Next, pure water 621.
The above-coated carrier was immersed in a mixed solution of 757.8 g of lanthanum nitrate and 767.1 g of neodymium nitrate dissolved in 8 g, bowed, and the excess moisture was blown off.
After drying at 0°C for 1 hour, it was fired at 700°C for 2 hours.
次いで、この担体を硝酸パラジウム水溶液に撹拌しなが
ら２時間浸漬した後、引き上げ乾燥した。更に、この担
体を硝酸ロジウム水溶液に攪拌しながら１時間浸漬した
後、引き上げ乾燥した。Next, this carrier was immersed in an aqueous palladium nitrate solution for 2 hours while stirring, and then taken up and dried. Further, this carrier was immersed in an aqueous rhodium nitrate solution for 1 hour while stirring, and then taken up and dried.
このようにして、Ｎｄ、 Ｌａ、 Ｐｄ及びＲｈを触媒
成分として担持している触媒ＩＩを得た。In this way, catalyst II supporting Nd, La, Pd, and Rh as catalyst components was obtained.
実施例及び比較例より得られた各触媒の成分含有量を第
１表に示す。Table 1 shows the component contents of each catalyst obtained in Examples and Comparative Examples.
第１表
比（Ａ／Ｆ） １４．６、空間速度（ＳＶ） ６０００
０ Ｈｒ−及び触媒床温度８００℃で２００時間運転し
た。Table 1 Ratio (A/F) 14.6, Space velocity (SV) 6000
It was operated for 200 hours at 0 Hr- and a catalyst bed temperature of 800°C.
浄化性能については、空燃比１４．６のエンジン排気ガ
スを模したモデル排気ガスを用い、５ｖ＝８５ＱＯＯＨ
ｒ−’として触媒を通過させ、Ｃｏ、 ＩＣ及びＮＯｘ
の浄化率を測定した。Regarding the purification performance, we used a model exhaust gas that imitated engine exhaust gas with an air-fuel ratio of 14.6, and 5v = 85QOOH.
pass through the catalyst as r-', Co, IC and NOx
The purification rate was measured.
測定の結果得られたＧＯ，ＨＣ及びＮＯｘの浄化率を第
２表に示す。Table 2 shows the purification rates of GO, HC, and NOx obtained as a result of the measurement.
第２表
〈耐久試験〉
これら２種の触媒に対し、以下の方法により耐久試験を
実施し、浄化性能を評価した。Table 2 (Durability Test) A durability test was conducted on these two types of catalysts using the following method to evaluate their purification performance.
耐久試験は、６気筒２８００ｃｃエンジン（５Ｍ−Ｇ）
の排気系に触媒を設置する方法で、空燃次に各触媒１．
ＩＩにおけるＰｄ及びＲｈの平均粒子径をＸ線回折によ
り測定した。その結果を第３表に示す。Durability test was conducted using a 6-cylinder 2800cc engine (5M-G)
In this method, a catalyst is installed in the exhaust system of the air/fuel mixture, and then each catalyst 1.
The average particle diameters of Pd and Rh in II were measured by X-ray diffraction. The results are shown in Table 3.
第３表
に良好に形成されている。そのためＰｄ及びＲｈの粒成
長が抑制され、それらの貴金属を無駄なく有利に利用で
きるとともに、触媒活性及び耐久性が向上した。又、Ｐ
ｄとＲｈが分離されるので、ＰｄがＲｈの表面を覆って
その触媒性能を低下させるという悪い相互作用もみられ
ない。It is well formed in Table 3. Therefore, the grain growth of Pd and Rh was suppressed, and these precious metals could be used advantageously without waste, and the catalytic activity and durability were improved. Also, P
Since d and Rh are separated, there is no adverse interaction in which Pd covers the surface of Rh and reduces its catalytic performance.
第２表から明らかな如く、本実施例に係る触媒Ｉは、比
較例に係る触媒ＩＩよりも耐久試験後の活性が一段と優
れている。これはＦ’ｄ、 Ｒｈの粒成長抑制効果の違
いであることが第３表から認められた。As is clear from Table 2, Catalyst I according to this example has a much better activity after the durability test than Catalyst II according to Comparative Example. It was recognized from Table 3 that this was due to the difference in the grain growth inhibiting effects of F'd and Rh.
上述の如く、本発明の排気ガス浄化用触媒は、Ｐｄ−Ｎ
ｄ共沈物とＲｈ−Ｌａ共沈物を用いて製造される触媒で
あるためＰｄとＮｄの、並びにＲｈとＬａの混合状態が
非常に良く、焼成によってＰｄ−Ｎｄ複合酸化物及びＲ
ｂ−Ｌａ複合酸化物が今まで以上時
許
出
願
人
トヨタ自動車株式会社
（ばか２名）As mentioned above, the exhaust gas purifying catalyst of the present invention is made of Pd-N
Since the catalyst is manufactured using a d coprecipitate and a Rh-La coprecipitate, the mixing state of Pd and Nd and Rh and La is very good, and when fired, Pd-Nd composite oxide and R
b-La composite oxide is available now more than ever Applicant Toyota Motor Corporation (two idiots)
Claims (1)
ｈ・Ｌａ共沈物から生じたＲｈ・Ｌａ複合酸化物が耐火
性担体上のアルミナコート層に含まれていることを特徴
とする排気ガス浄化用触媒。Pd/Nd composite oxide generated from Pd/Nd coprecipitate and R
An exhaust gas purifying catalyst characterized in that a Rh/La composite oxide produced from an h/La coprecipitate is contained in an alumina coat layer on a refractory carrier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63255466A JPH02102735A (en) | 1988-10-11 | 1988-10-11 | Catalyst for purification of exhaust gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63255466A JPH02102735A (en) | 1988-10-11 | 1988-10-11 | Catalyst for purification of exhaust gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02102735A true JPH02102735A (en) | 1990-04-16 |
Family
ID=17279157
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63255466A Pending JPH02102735A (en) | 1988-10-11 | 1988-10-11 | Catalyst for purification of exhaust gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02102735A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11137999A (en) * | 1997-11-12 | 1999-05-25 | Jisedai Haigas Shokubai Kenkyusho:Kk | Purification catalyst for waste gas and its production |
| US10830710B2 (en) | 2019-02-19 | 2020-11-10 | Toshiba Memory Corporation | Method and device for inspecting a semiconductor device |
| US10906816B2 (en) | 2016-07-29 | 2021-02-02 | Sumitomo Chemical Company, Limited | Alumina and method for producing automotive catalyst using same |
-
1988
- 1988-10-11 JP JP63255466A patent/JPH02102735A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11137999A (en) * | 1997-11-12 | 1999-05-25 | Jisedai Haigas Shokubai Kenkyusho:Kk | Purification catalyst for waste gas and its production |
| US10906816B2 (en) | 2016-07-29 | 2021-02-02 | Sumitomo Chemical Company, Limited | Alumina and method for producing automotive catalyst using same |
| US10830710B2 (en) | 2019-02-19 | 2020-11-10 | Toshiba Memory Corporation | Method and device for inspecting a semiconductor device |
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