JPH088991B2 - Method for producing oxidation catalyst - Google Patents
Method for producing oxidation catalystInfo
- Publication number
- JPH088991B2 JPH088991B2 JP62070582A JP7058287A JPH088991B2 JP H088991 B2 JPH088991 B2 JP H088991B2 JP 62070582 A JP62070582 A JP 62070582A JP 7058287 A JP7058287 A JP 7058287A JP H088991 B2 JPH088991 B2 JP H088991B2
- Authority
- JP
- Japan
- Prior art keywords
- oxidation catalyst
- nitric acid
- activated alumina
- carrier
- solution
- 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.)
- Expired - Fee Related
Links
Landscapes
- Catalysts (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、炭化水素系燃料を酸化する為の、活性アル
ミナをコートした担体上にPt粒子を均一微細に分散し担
持させた酸化用触媒の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an oxidation catalyst in which Pt particles are uniformly and finely dispersed and supported on a carrier coated with activated alumina for oxidizing a hydrocarbon fuel. The present invention relates to a manufacturing method of.
（従来の技術とその問題点） 従来から酸化用の触媒としては、Pt担持触媒が広く利
用されており、特に近年は活性アルミナをコートした担
体上に高触媒性能のPt粒子を最小限に担持させるPt担持
触媒の開発がなされている。(Prior art and its problems) As a catalyst for oxidation, a Pt-supported catalyst has been widely used, and in recent years, Pt particles with high catalytic performance have been supported to a minimum on a carrier coated with activated alumina. Development of Pt-supported catalysts has been made.
然し乍らPt（NH3）２（NO2）２は微粉末状であり、水
や硝酸には常温で殆んど溶解しない。従ってPt金属の担
持量を多くする為には、水又は硝酸溶液中にコロイド状
に均一に分散せざるを得なかった。However, Pt (NH 3 ) 2 (NO 2 ) 2 is in the form of fine powder and is hardly dissolved in water or nitric acid at room temperature. Therefore, in order to increase the amount of Pt metal supported, it was unavoidable to uniformly disperse it in a colloidal state in water or a nitric acid solution.
本発明はかかる問題点を解決すべくなされたものであ
り、活性アルミナをコートした担体上にPt粒子を均一微
細に担持した高活性の酸化用触媒の製造方法を提供せん
とするものである。The present invention has been made to solve the above problems, and an object thereof is to provide a method for producing a highly active oxidation catalyst in which Pt particles are uniformly and finely supported on a carrier coated with activated alumina.
本発明による酸化用触媒の製造方法は、Pt（NH3）２
（NO2）２を硝酸水溶液に添加した混合液を、60〜100℃
の温度範囲で溶解し且つ熟成し、次に熟成し終えた後調
整した水溶液に活性アルミナをコートした担体を浸漬
し、次いでこの担体に含浸した水溶液のPt化合物を還元
させることを特徴とするものである。The method for producing an oxidation catalyst according to the present invention is based on Pt (NH 3 ) 2
Mix the mixture of (NO 2 ) 2 and nitric acid in water at 60-100 ° C.
Characterized by dissolving and aging in the temperature range of, then immersing the carrier coated with activated alumina in the adjusted aqueous solution after finishing the aging, and then reducing the Pt compound of the aqueous solution impregnated in this carrier Is.
次に本発明の酸化用触媒の製造方法に於いて、Pt（NH
3）２（NO2）２を硝酸水溶液に添加した混合液を、60〜
100℃の温度範囲で溶解し、且つ熟成する理由について
詳述する。本発明者等はこの分散中のPt（NH3）２（N
O2）２を溶解すべく加熱していたところ、60℃の温度か
ら溶解し始めること、つまり60℃の温度が溶解の反応開
始温度であることを知見した。Next, in the method for producing an oxidation catalyst of the present invention, Pt (NH
3 ) Add a mixture of 2 (NO 2 ) 2 and nitric acid to 60-
The reason for melting and aging in the temperature range of 100 ° C. will be described in detail. The present inventors have found that Pt (NH 3 ) 2 (N
It was found that when O 2 ) 2 was heated to dissolve, it started to dissolve at a temperature of 60 ° C., that is, the temperature of 60 ° C. was a reaction initiation temperature for dissolution.
しかし溶解反応温度が100℃を超えると、上記化合物
の分解が生じ、水溶液中にPt化合物の沈澱が生じる。However, when the dissolution reaction temperature exceeds 100 ° C., the above compounds are decomposed and the Pt compound is precipitated in the aqueous solution.
従って前記分散中のPt（NH3）２（NO2）２を溶解する
には60〜100℃が良い。Therefore, 60 to 100 ° C. is good for dissolving Pt (NH 3 ) 2 (NO 2 ) 2 in the dispersion.
また硝酸水溶液中のHNO3量が極端に多い場合、例えば
450g/を超えると、Pt（NH3）２（NO2）２を添加した
際不安定となり、Pt化合物の沈澱が生じる。逆にHNO3量
が極端に少ない場合、例えば250g/に満たないと、そ
のHNO3量に応じたPt（NH3）２（NO2）２が溶解すると思
われるが溶解しきれないPt（NH3）２（NO2）２粉末は硝
酸水溶液中に残る。従って硝酸水溶液中のHNO3量は250g
/〜450g/がより好ましい。When the amount of HNO 3 in the nitric acid aqueous solution is extremely large, for example,
When it exceeds 450 g /, it becomes unstable when Pt (NH 3 ) 2 (NO 2 ) 2 is added, and precipitation of the Pt compound occurs. On the contrary, when the amount of HNO 3 is extremely small, for example, if it is less than 250 g /, Pt (NH 3 ) 2 (NO 2 ) 2 corresponding to the amount of HNO 3 seems to be dissolved, but Pt (NH 3 ) 2 (NO 2 ) 2 powder remains in the nitric acid solution. Therefore, the amount of HNO 3 in the nitric acid solution is 250 g.
/ ~ 450g / is more preferable.
Pt（NH3）２（NO2）２が硝酸水溶液中に完全に溶解す
ると、この溶液は適切な溶解反応温度内で熟成される。
この際、溶液の色は黄淡色から赤褐色、赤褐色から更に
濃い赤褐色へと変化していくので熟成されているのが判
る。When Pt (NH 3 ) 2 (NO 2 ) 2 is completely dissolved in the aqueous nitric acid solution, the solution is aged at an appropriate dissolution reaction temperature.
At this time, the color of the solution changed from yellowish pale to reddish brown, and from reddish brown to darker reddish brown, it can be seen that the solution was aged.
然してこの熟成に於いて、最初のPt（NH3）２（NO2）
２の濃度が十分でないと、活性アルミナをコートした担
体に担持した際、Ptの分散が悪く、酸化用触媒としては
不十分である。即ちPt（NH3）２（NO2）２の濃度がPt金
属として450g/を超えていると、活性アルミナ担体を
コートした担体に担持して還元した際、Pt粒子が凝集し
て巨大化する。また逆にPt金属として250g/に満たな
いと、活性アルミナをコートした担体に担持して還元し
た際、微細なPt粒子が偏って分散する。従ってPt金属と
して250g/〜450g/を含むPt（NH3）２（NO2）２なら
ばより好ましくは適度な熟成時間、例えばPt金属として
300g/を含むPt（NH3）２（NO2）２の場合温度80℃で
９時間〜15時間あれば十分熟成できる。そして十分熟成
し終えた液は担持するPt金属の量に応じて適宜水又は硝
酸水溶液及び添加剤等で希釈して活性アルミナをコート
した担体に担持することができるものである。However, in this aging, the first Pt (NH 3 ) 2 (NO 2 )
If the concentration of 2 is not sufficient, Pt is not well dispersed when loaded on a carrier coated with activated alumina, and is insufficient as an oxidation catalyst. That is, when the concentration of Pt (NH 3 ) 2 (NO 2 ) 2 exceeds 450 g / as Pt metal, Pt particles agglomerate and become huge when loaded on a carrier coated with an activated alumina carrier and reduced. . On the contrary, if the Pt metal is less than 250 g /, fine Pt particles are unevenly dispersed when the Pt metal is carried on a carrier coated with activated alumina and reduced. Therefore, if Pt (NH 3 ) 2 (NO 2 ) 2 containing 250 g / to 450 g / as Pt metal is used, more preferable moderate aging time, for example, as Pt metal
In the case of Pt (NH 3 ) 2 (NO 2 ) 2 containing 300 g /, sufficient aging can be achieved if the temperature is 80 ° C. for 9 hours to 15 hours. Then, the liquid that has been sufficiently aged can be appropriately diluted with water or a nitric acid aqueous solution, an additive and the like according to the amount of Pt metal to be carried, and can be carried on a carrier coated with activated alumina.
以下に本発明の実施例及び従来例について述べる。 Examples of the present invention and conventional examples will be described below.
（実施例） Pt（NH3）２（NO2）２結晶100gを、あらかじめ80℃に
加熱しておいた硝酸溶液（4N）220mlに徐々に投入して
いき、結晶を溶解させる。次いで1Hrs加温し続けて熟成
させたPt化合物硝酸溶液を作成した。 (Example) Pt (NH 3) 2 ( NO 2) 2 crystals 100 g, gradually put into pre-heated to 80 ° C. which had been nitric acid solution (4N) 220 ml, to dissolve the crystals. Next, a Pt compound nitric acid solution was prepared which was aged by continuously heating for 1 Hrs.
この水溶液に活性アルミナをコートをしたセラミック
担体を浸漬し、次いでこの担体に含浸した水溶液のPt化
合物を還元してPt担持した酸化用触媒を得た。A ceramic carrier coated with activated alumina was immersed in this aqueous solution, and then the Pt compound in the aqueous solution impregnated in this carrier was reduced to obtain a Pt-supported oxidation catalyst.
（従来例） Pt（NH3）２（NO2）２粉末（Pt金属として300g）をHN
O3量300g入った１の硝酸水溶液に添加して、常温で溶
解しようとしたところ、完全に溶解することができなく
コロイド溶液となった。このコロイド溶液に活性アルミ
ナをコートした担体を浸漬し、次いでこの担体に含浸し
たPt化合物を還元してPt担持の酸化用触媒を得た。(Conventional example) Pt (NH 3 ) 2 (NO 2 ) 2 powder (300g as Pt metal) was added to HN
When it was added to an aqueous solution of nitric acid containing 300 g of O 3 and tried to dissolve it at room temperature, it could not be completely dissolved and a colloidal solution was obtained. A carrier coated with activated alumina was immersed in this colloidal solution, and then the Pt compound impregnated in the carrier was reduced to obtain a Pt-supported oxidation catalyst.
然して上記実施例及び従来例で得られた触媒について
初期活性試験、即ち触媒120gを用いてメタン90％を含む
天然ガスの接触燃焼を常圧下、空気量60Nm3/時、触媒入
口部ガス流速20m/sec低温着火性能を測定する試験を行
ったところ、実施例の触媒な300℃、従来例は370℃であ
った。Therefore, the catalysts obtained in the above-mentioned examples and conventional examples were subjected to an initial activity test, that is, catalytic combustion of natural gas containing 90% of methane using 120 g of catalyst under normal pressure, air amount of 60 Nm 3 / hour, catalyst inlet gas flow rate of 20 m. A test for measuring the low temperature ignition performance was performed at 300 ° C. for the catalyst of the example and 370 ° C. for the conventional example.
かように実施例の触媒は初期活性温度が低いのに対
し、従来例の触媒は初期活性温度が高い。また走査型電
子顕微鏡でPt粒子の分散を調べたところ、実施例の触媒
は均一、微細に分散していたのに対し、従来例の触媒は
偏ったPt粒子の分散が観察され、またPt粒子の凝集が観
察された。As described above, the catalysts of the examples have a low initial activation temperature, whereas the catalysts of the conventional examples have a high initial activation temperature. Moreover, when the dispersion of Pt particles was examined by a scanning electron microscope, the catalyst of the example was uniformly dispersed, whereas the catalyst of the conventional example was observed to have a biased dispersion of Pt particles. Aggregation was observed.
（発明の効果） 以上の説明で判るように本発明の酸化用触媒の製造方
法によれば、Pt粒子が均一微細に分散され、初期活性に
優れたPt担持の酸化用触媒を作ることができるという実
利的な効果がある。(Effects of the Invention) As can be seen from the above description, according to the method for producing an oxidation catalyst of the present invention, it is possible to produce a Pt-supported oxidation catalyst in which Pt particles are uniformly and finely dispersed and which is excellent in initial activity. There is a pragmatic effect.
Claims (1)
した混合液を60〜100℃の温度範囲で溶解し且つ熟成
し、次に熟成し終えた水溶液に活性アルミナをコートし
た担体を浸漬し、次いでこの担体に含浸した水溶液のPt
化合物を還元することを特徴とする酸化用触媒の製造方
法。1. A mixed solution prepared by adding dinitrodiammine Pt to an aqueous nitric acid solution is melted and aged in a temperature range of 60 to 100 ° C., and then a carrier coated with activated alumina is immersed in the aged aqueous solution, and then, Pt of aqueous solution impregnated in this carrier
A method for producing an oxidation catalyst, which comprises reducing a compound.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62070582A JPH088991B2 (en) | 1987-03-25 | 1987-03-25 | Method for producing oxidation catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62070582A JPH088991B2 (en) | 1987-03-25 | 1987-03-25 | Method for producing oxidation catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63236540A JPS63236540A (en) | 1988-10-03 |
| JPH088991B2 true JPH088991B2 (en) | 1996-01-31 |
Family
ID=13435693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62070582A Expired - Fee Related JPH088991B2 (en) | 1987-03-25 | 1987-03-25 | Method for producing oxidation catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH088991B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6614897B2 (en) * | 2015-02-26 | 2019-12-04 | 大阪瓦斯株式会社 | Methane oxidation removal catalyst manufacturing method and methane oxidation removal method |
-
1987
- 1987-03-25 JP JP62070582A patent/JPH088991B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63236540A (en) | 1988-10-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |