JPH04271843A - Production of catalyst for purification of exhaust gas - Google Patents
Production of catalyst for purification of exhaust gasInfo
- Publication number
- JPH04271843A JPH04271843A JP3032641A JP3264191A JPH04271843A JP H04271843 A JPH04271843 A JP H04271843A JP 3032641 A JP3032641 A JP 3032641A JP 3264191 A JP3264191 A JP 3264191A JP H04271843 A JPH04271843 A JP H04271843A
- Authority
- JP
- Japan
- Prior art keywords
- zeolite
- catalyst
- exhaust gas
- purification
- 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 abstract description 30
- 238000000746 purification Methods 0.000 title abstract description 15
- 238000004519 manufacturing process Methods 0.000 title description 8
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 claims abstract description 67
- 229910021536 Zeolite Inorganic materials 0.000 claims abstract description 64
- 239000010457 zeolite Substances 0.000 claims abstract description 64
- 239000000843 powder Substances 0.000 claims abstract description 29
- 239000011148 porous material Substances 0.000 claims abstract description 11
- 239000002002 slurry Substances 0.000 claims abstract description 7
- 238000005342 ion exchange Methods 0.000 claims abstract description 6
- 239000000919 ceramic Substances 0.000 claims abstract description 3
- 229910052751 metal Inorganic materials 0.000 claims abstract description 3
- 239000002184 metal Substances 0.000 claims abstract description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract 2
- 239000010949 copper Substances 0.000 claims description 22
- 239000007864 aqueous solution Substances 0.000 claims description 10
- 239000000243 solution Substances 0.000 claims description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 claims description 3
- 229910001431 copper ion Inorganic materials 0.000 claims description 3
- 238000000034 method Methods 0.000 claims description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 claims 1
- 150000002500 ions Chemical class 0.000 abstract description 5
- 230000001603 reducing effect Effects 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 4
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 239000011247 coating layer Substances 0.000 abstract 2
- 229940070337 ammonium silicofluoride Drugs 0.000 abstract 1
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 18
- 239000007789 gas Substances 0.000 description 14
- -1 ammonium fluorosilicate Chemical compound 0.000 description 11
- 229910052782 aluminium Inorganic materials 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- 229910002091 carbon monoxide Inorganic materials 0.000 description 4
- 229930195733 hydrocarbon Natural products 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 238000010335 hydrothermal treatment Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 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 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 229910000365 copper sulfate Inorganic materials 0.000 description 1
- BERDEBHAJNAUOM-UHFFFAOYSA-N copper(I) oxide Inorganic materials [Cu]O[Cu] BERDEBHAJNAUOM-UHFFFAOYSA-N 0.000 description 1
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 1
- ARUVKPQLZAKDPS-UHFFFAOYSA-L copper(II) sulfate Chemical compound [Cu+2].[O-][S+2]([O-])([O-])[O-] ARUVKPQLZAKDPS-UHFFFAOYSA-L 0.000 description 1
- OPQARKPSCNTWTJ-UHFFFAOYSA-L copper(ii) acetate Chemical compound [Cu+2].CC([O-])=O.CC([O-])=O OPQARKPSCNTWTJ-UHFFFAOYSA-L 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- KRFJLUBVMFXRPN-UHFFFAOYSA-N cuprous oxide Chemical compound [O-2].[Cu+].[Cu+] KRFJLUBVMFXRPN-UHFFFAOYSA-N 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
Description
【0001】0001
【産業上の利用分野】本発明は、自動車等の内燃機関や
硝酸製造工場などから排出される排気ガス中の窒素酸化
物を浄化する排気ガス浄化用触媒の製造方法に関し、更
に詳しくは NOx浄化活性を低下させることなく、耐
熱性を改良した排気ガス浄化用触媒の製造方法に関する
。[Industrial Application Field] The present invention relates to a method for manufacturing an exhaust gas purification catalyst for purifying nitrogen oxides in exhaust gas emitted from internal combustion engines such as automobiles and nitric acid manufacturing plants. The present invention relates to a method for producing an exhaust gas purifying catalyst with improved heat resistance without reducing activity.
【0002】0002
【従来の技術】自動車の排気ガス浄化用触媒として、一
酸化炭素(CO)及び炭化水素(HC)の酸化と、窒素
酸化物 (NOx)の還元を同時に行なう触媒が各種使
用されている。かかる触媒として銅とゼオライト粉末と
から成るCu/ゼオライト触媒も知られており、ゼオラ
イトの耐久性を向上させるために、Cu/ゼオライト触
媒を水熱処理して脱Alを行なった後、Cuをイオン交
換した触媒が知られている。2. Description of the Related Art Various types of catalysts that simultaneously oxidize carbon monoxide (CO) and hydrocarbons (HC) and reduce nitrogen oxides (NOx) are used as exhaust gas purifying catalysts for automobiles. A Cu/zeolite catalyst composed of copper and zeolite powder is also known as such a catalyst.In order to improve the durability of zeolite, the Cu/zeolite catalyst is hydrothermally treated to remove Al, and then the Cu is ion-exchanged. catalysts are known.
【0003】0003
【発明が解決しようとする課題】しかしながら、水熱処
理等により脱Al化処理したゼオライト粉末を用いた従
来のCu/ゼオライト触媒は脱Alがゼオライト粒子の
外表面だけでなく、細孔内部まで進み、その結果、ゼオ
ライトの表面近傍の細孔内のアルミニウムも脱Alされ
てしまい、耐熱性は向上するが、 NOxの反応に必要
な (Alの近傍に位置する) Cuイオンが担持でき
ず、 NOxの浄化率が低下するという問題があった。[Problems to be Solved by the Invention] However, in conventional Cu/zeolite catalysts that use zeolite powder that has been de-aluminum-treated by hydrothermal treatment etc., the de-aluminum proceeds not only to the outer surface of the zeolite particles but also to the inside of the pores. As a result, the aluminum in the pores near the surface of the zeolite is also de-aluminum, improving heat resistance, but the Cu ions (located near Al) necessary for the NOx reaction cannot be supported, and the NOx There was a problem that the purification rate decreased.
【0004】従って、本発明は、前記した従来のCu/
ゼオライト NOx浄化用触媒の問題点を解決し、 N
Ox浄化率を実質的に低下させることなく、Cu/ゼオ
ライト触媒の耐熱性を著しく改良することができる排気
ガス浄化用触媒の製造方法を開発することを目的とする
。[0004] Therefore, the present invention is directed to the above-mentioned conventional Cu/
Zeolite solves the problems of NOx purification catalysts and
The purpose of the present invention is to develop a method for producing an exhaust gas purification catalyst that can significantly improve the heat resistance of a Cu/zeolite catalyst without substantially lowering the Ox purification rate.
【0005】[0005]
【課題を解決するための手段】本発明に従えば、(i)
ケイフッ化アンモニウム[(NH4)2SiF ]水溶
液中にゼオライト粉末を浸漬して加熱、攪拌し、 (i
i) 該ゼオライト粉末を取り出してゼオライトスラリ
ーを調製し、(iii) 該ゼオライトスラリーを、セ
ラミック又はメタル担体にウォッシュコートして、担体
の細孔表面上にゼオライトコート層を形成し、そして(
iv)該担体を銅イオン水溶液に浸漬してゼオライトコ
ート層にCuをイオン交換することから成る排気ガス浄
化用触媒の製造方法が提供される。[Means for solving the problems] According to the present invention, (i)
Zeolite powder was immersed in an aqueous solution of ammonium fluorosilicate [(NH4)2SiF], heated and stirred, and (i
i) removing the zeolite powder to prepare a zeolite slurry; (iii) washcoating the zeolite slurry onto a ceramic or metal carrier to form a zeolite coat layer on the pore surface of the carrier;
iv) A method for producing an exhaust gas purifying catalyst is provided, which comprises immersing the carrier in an aqueous copper ion solution to ion-exchange Cu onto the zeolite coat layer.
【0006】本発明の排気ガス浄化用触媒の製造方法に
よれば、ゼオライト粉末の細孔内のアルミニウムは実質
的にまったく除去せず、ゼオライト外表面のアルミニウ
ムのみを脱Alし、次にこのゼオライトに、Cuを、常
法により、イオン交換により担持することにより、 N
Ox浄化活性を実質的に低下させることなく、耐熱性に
優れた排気ガス浄化用触媒を製造することができる。According to the method for producing an exhaust gas purifying catalyst of the present invention, aluminum in the pores of the zeolite powder is not substantially removed at all, only the aluminum on the outer surface of the zeolite is dealt with, and then the zeolite is By supporting Cu by ion exchange using a conventional method, N
An exhaust gas purification catalyst with excellent heat resistance can be produced without substantially reducing Ox purification activity.
【0007】従来のCu/ゼオライト触媒の熱劣化の主
要因の1つとして、イオン交換サイトから、 CuO,
Cu2O等の形でゼオライト粉末外表面に存在する銅と
ゼオライト粉末中のアルミニウムとの反応によって複合
酸化物が生成し、これが結晶破壊を起こすものと考えら
れている。
従って、本発明者らはゼオライト粉末の外表面に存在す
るアルミニウムのみを脱アルミニウムすれば、結晶破壊
が防止でき、触媒の耐熱性を著しく改良することができ
ると考え、鋭意研究の結果、ゼオライト粉末をケイフッ
化アンモニウム水溶液中に浸漬してAlをSiで置換す
ることによりゼオライト粉末の表面に存在するAlのみ
を選択的にSiで置換除去することができることを見出
した。[0007] One of the main causes of thermal deterioration of conventional Cu/zeolite catalysts is that CuO,
It is believed that a complex oxide is produced by the reaction between copper present on the outer surface of the zeolite powder in the form of Cu2O, etc. and aluminum in the zeolite powder, and this causes crystal destruction. Therefore, the present inventors believed that by dealuminating only the aluminum present on the outer surface of zeolite powder, crystal destruction could be prevented and the heat resistance of the catalyst could be significantly improved, and as a result of intensive research, zeolite powder It has been found that only the Al present on the surface of the zeolite powder can be selectively removed by replacing it with Si by immersing it in an aqueous ammonium fluorosilicate solution to replace Al with Si.
【0008】本発明の排気ガス浄化用触媒の製造方法に
おいて使用されるゼオライト粉末は天然ゼオライト及び
合成ゼオライトの任意のものを使用することができ、こ
れをケイフッ化アンモニウム水溶液(水溶液の濃度には
特に限定はなく、一般には1〜10重量%水溶液として
使用される)中に浸漬する。ゼオライトの粒度等にも特
に限定はなく、またケイフッ化アンモニウムは市販のも
のを使用することができる。ケイフッ化アンモニウム水
溶液に浸漬したゼオライトは、例えば60〜90℃の温
度に加熱攪拌する(加熱時間にも特に制限はないが一般
には3〜24時間で十分である)。これによりゼオライ
トの表面に存在するAlがSiに置換される。このよう
にして表面に存在するアルミニウムを脱Alしたゼオラ
イト粉末はスラリー状態で適当な担体にコートし、ゼオ
ライトコート層に常法によって銅イオン水溶液(例えば
硫酸銅、硝酸銅などの鉱酸塩又は酢酸銅などの有機酸塩
水溶液)に浸漬してゼオライトコート層に銅をイオン交
換させることによって所望の排気ガス浄化用触媒を製造
することができる。The zeolite powder used in the method for producing an exhaust gas purifying catalyst of the present invention can be any natural zeolite or synthetic zeolite, and is mixed with an aqueous ammonium fluorosilicate solution (the concentration of the aqueous solution is (No limitation, generally used as a 1-10% by weight aqueous solution). There are no particular limitations on the particle size of the zeolite, and commercially available ammonium fluorosilicate can be used. The zeolite immersed in the aqueous ammonium fluorosilicate solution is heated and stirred, for example, at a temperature of 60 to 90°C (there are no particular restrictions on the heating time, but 3 to 24 hours is generally sufficient). As a result, Al present on the surface of the zeolite is replaced with Si. The zeolite powder, which has been freed from aluminum present on the surface in this way, is coated in a slurry state on a suitable carrier, and the zeolite coat layer is coated with a copper ion aqueous solution (e.g., mineral acid salts such as copper sulfate, copper nitrate, or acetic acid) by a conventional method. A desired exhaust gas purifying catalyst can be produced by ion-exchanging copper with the zeolite coat layer by immersing the catalyst in an aqueous solution of an organic acid salt such as copper.
【0009】[0009]
【作用】本発明に従ったCu/ゼオライト触媒はゼオラ
イト粉末をケイフッ化アンモニウム水溶液中に浸漬して
、ゼオライトのアルミニウムを脱Alするので(ケイフ
ッ化アンモニウムの大きさはゼオライト粉末の細孔より
大きいから)、ゼオライト粉末の外表面に存在するAl
のみがSiで置換されて細孔内のAlはそのまま担持さ
れているため、Cuイオンの担持量が減少せず、 NO
x浄化率は実質的に低下することなく、触媒の耐熱性を
高めることができる。[Operation] The Cu/zeolite catalyst according to the present invention deals aluminum of the zeolite by immersing the zeolite powder in an aqueous ammonium fluorosilicate solution (because the size of ammonium fluorosilicate is larger than the pores of the zeolite powder). ), Al present on the outer surface of zeolite powder
Since only the Cu ions are replaced with Si and the Al in the pores is supported as is, the amount of supported Cu ions does not decrease, and NO
x The heat resistance of the catalyst can be increased without substantially reducing the purification rate.
【0010】0010
【実施例】以下、実施例に従って本発明を更に具体的に
説明するが、本発明の範囲を以下の実施例に限定するも
のでないことはいうまでもない。EXAMPLES The present invention will be explained in more detail below with reference to Examples, but it goes without saying that the scope of the present invention is not limited to the following Examples.
【0011】実施例1
Si/Al比が20のH型−ZSM−5ゼオライト粉末
(東ソー(株)製)を、このゼオライト粉末1g当り
0.2Mのケイフッ化アンモニウム[(NH4)2Si
F ]水溶液25ccの水溶液中に加え、温度90℃で
20時間攪拌した。この間、ケイフッ化アンモニウムは
ZSM−5ゼオライトの細孔より大きいため、ゼオライ
ト粉末の外表面に存在するAlのみがSiで置換される
。次いで、この粉末を蒸留水で洗浄した。Example 1 H type-ZSM-5 zeolite powder (manufactured by Tosoh Corporation) with a Si/Al ratio of 20 was added per 1 g of this zeolite powder.
0.2M ammonium fluorosilicate [(NH4)2Si
F ] aqueous solution was added to 25 cc of an aqueous solution and stirred at a temperature of 90° C. for 20 hours. During this time, since the pores of ammonium fluorosilicate are larger than the pores of ZSM-5 zeolite, only Al present on the outer surface of the zeolite powder is replaced with Si. This powder was then washed with distilled water.
【0012】上記方法で調製した脱Alゼオライト粉末
50重量部、シリカゾル (20重量%SiO2) 7
0重量部、純水15重量部及び40重量%硝酸アルミニ
ウム水溶液15重量部を混合して攪拌し、30mmφ×
50mm長 (体積35cc) のコージュライト製モ
ノリステストピースにウォッシュコートし、温度 50
0℃で3時間焼成した。50 parts by weight of Al-free zeolite powder prepared by the above method, silica sol (20% by weight SiO2) 7
0 parts by weight, 15 parts by weight of pure water, and 15 parts by weight of a 40% by weight aluminum nitrate aqueous solution were mixed and stirred to form a 30 mmφ×
A 50 mm long (volume 35 cc) cordierite monolith test piece was wash coated and the temperature was 50°C.
It was baked at 0°C for 3 hours.
【0013】次いで、上で得られたゼオライトコート層
を有するゼオライト粉末を別途調製した0.02M酢酸
銅水溶液に適当時間(例えば3〜10時間)浸漬してゼ
オライトコート層にCuをイオン交換させることにより
担体1リットル当り2.88gのCuを担持した。[0013] Next, the zeolite powder having the zeolite coat layer obtained above is immersed in a separately prepared 0.02M copper acetate aqueous solution for an appropriate time (for example, 3 to 10 hours) to ion-exchange Cu in the zeolite coat layer. 2.88 g of Cu was supported per liter of carrier.
【0014】比較例1
実施例1で用いたSi/Al比が20のH型−ZSM−
5ゼオライト粉末を用いて、脱アルミニウム処理を行な
わずに、実施例1と同様にしてモノリステストピースを
調製した。Comparative Example 1 H type-ZSM- with a Si/Al ratio of 20 used in Example 1
A monolith test piece was prepared in the same manner as in Example 1 using No. 5 zeolite powder and without dealumination treatment.
【0015】比較例2
実施例1で用いたSi/Al比が20のH型−ZSM−
5ゼオライト粉末を用いて、水蒸気雰囲気中にて温度
550℃で 100時間水熱処理し、実施例1と同様に
してモノリステストピースを調製した。Comparative Example 2 H type-ZSM- with a Si/Al ratio of 20 used in Example 1
5 Using zeolite powder, the temperature was
A monolith test piece was prepared in the same manner as in Example 1 by hydrothermal treatment at 550°C for 100 hours.
【0016】性能試験
実施例1並びに比較例1及び2で調製した3種類の触媒
に、空気中において温度 800℃で1時間熱処理を施
し、その後これらの触媒の排気ガス浄化性能を評価した
。試験条件は以下の通りである。
入ガス温度: 400℃、
S.V.(空間速度)=60,000hr−1、A/F
=22。
得られた結果を表1に示す。なお表1において、HCは
炭化水素、COは一酸化炭素を示す。Performance Test The three types of catalysts prepared in Example 1 and Comparative Examples 1 and 2 were heat treated in air at a temperature of 800° C. for 1 hour, and then the exhaust gas purification performance of these catalysts was evaluated. The test conditions are as follows. Inlet gas temperature: 400℃, S. V. (Space velocity) = 60,000hr-1, A/F
=22. The results obtained are shown in Table 1. In Table 1, HC represents hydrocarbon and CO represents carbon monoxide.
【0017】[0017]
【表1】[Table 1]
【0018】表1に示すように、ゼオライト粉末の外表
面のみを脱Al化することにより、Cu/ゼオライト触
媒の耐熱性が格段に向上することが明らかである。[0018] As shown in Table 1, it is clear that the heat resistance of the Cu/zeolite catalyst is significantly improved by de-Alizing only the outer surface of the zeolite powder.
【0019】[0019]
【発明の効果】本発明に従えば、ゼオライト粉末をケイ
フッ化アンモニウム水溶液中に浸漬すると、ゼオライト
粒子の外表面のみが脱Alされてゼオライト粒子の細孔
内部が脱Al化されないので、 NOxの浄化に必要な
Cuイオンが十分に担持されるので、 NOx浄化活性
を低下させることなく排気ガス浄化触媒の耐熱性を高め
ることができる。[Effects of the Invention] According to the present invention, when zeolite powder is immersed in an aqueous ammonium fluorosilicate solution, only the outer surface of the zeolite particles is dealumined and the inside of the pores of the zeolite particles are not dealuminated, thereby purifying NOx. Since the Cu ions required for the exhaust gas purification catalyst are sufficiently supported, the heat resistance of the exhaust gas purification catalyst can be improved without reducing the NOx purification activity.
Claims (1)
NH4)2SiF ]水溶液中にゼオライト粉末を浸漬
して加熱、攪拌し、(ii)該ゼオライト粉末を取り出
してゼオライトスラリーを調製し、(iii)該ゼオラ
イトスラリーを、セラミック又はメタル担体にウォッシ
ュコートして、担体の細孔表面上にゼオライトコート層
を形成し、そして(iv)該担体を銅イオン水溶液に浸
漬してゼオライトコート層に銅をイオン交換することを
特徴とする排気ガス浄化用触媒の製造方法。Claim 1: (i) Ammonium fluorosilicide [(
NH4)2SiF] Zeolite powder is immersed in an aqueous solution, heated and stirred, (ii) the zeolite powder is taken out to prepare a zeolite slurry, and (iii) the zeolite slurry is wash-coated on a ceramic or metal carrier. , forming a zeolite coat layer on the pore surface of a carrier, and (iv) immersing the carrier in an aqueous copper ion solution to ion-exchange copper with the zeolite coat layer. Method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3032641A JPH04271843A (en) | 1991-02-27 | 1991-02-27 | Production of catalyst for purification of exhaust gas |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3032641A JPH04271843A (en) | 1991-02-27 | 1991-02-27 | Production of catalyst for purification of exhaust gas |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH04271843A true JPH04271843A (en) | 1992-09-28 |
Family
ID=12364479
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP3032641A Pending JPH04271843A (en) | 1991-02-27 | 1991-02-27 | Production of catalyst for purification of exhaust gas |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH04271843A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5449504A (en) * | 1992-12-03 | 1995-09-12 | Tosoh Corporation | Process for removing nitrogen oxides from oxygen rich exhaust gas |
-
1991
- 1991-02-27 JP JP3032641A patent/JPH04271843A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5449504A (en) * | 1992-12-03 | 1995-09-12 | Tosoh Corporation | Process for removing nitrogen oxides from oxygen rich exhaust gas |
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