JPS607940A - Manganese catalyst - Google Patents

Abstract

PURPOSE:To obtain Mn catalyst having high activity and high decomposition performance for O3 both at low temp. by adding soln. contg. an oxidizing agent and permanganate to a solution mixture of soluble salts of Mn and Cu. CONSTITUTION:After adding an oxidizing agent (e.g. aq. H2O2) to a solution mixture of soluble Mn salt such as Mn sulphate and soluble Cu salt such as CuSO4, the mixture is neutralized with alkali soln. contg. permanganate. Obtd. precipitate is separated by filtration and dried, and then molded together with alumina sol to pellets and dried again to complete prepn. of Mn catalyst. Obtd. catalyst has high oxidation activity at low temp. and removes effectively CO contained in gas. It has superior decomposition characteristic of O3 at low temp., and removes O3 contained in gas effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention removes all of the carbon monoxide (CO) contained in gas containing manganese and copper, as well as the ozone (contained in NOF). 0,) is related to f unique.

Oxidation catalysts containing mankan include mankan, copper,
A fobcalide catalyst obtained by co-precipitating all soluble salts such as cobalt and silver is known.

Bobcalide catalysts are used as acidification catalysts at low temperatures, for example, for CO removal for gas masks. Up to now, various improved catalysts using 1 g of phocalide as insect carriers have been proposed, but basically none of them can change the overall performance of the phocalide catalyst, and it is necessary to further improve the catalytic activity at low temperatures. there were.

However, recently a new method for producing a manganese dioxide oxidation catalyst has been proposed, for example, Japanese Patent Application Laid-Open No. 17637/1983. This method creates a suspension of by-product manganese dioxide (alkali gold (alpha manganese dioxide)) produced from potassium permanganate used to oxidize organic matter under alkaline conditions.
This is a method for producing a heavy metal manganese dioxide oxidation catalyst by substituting an alkali metal at a pH that is at least 0.5 liters lower than the pH at which the hydroxides of heavy metals such as copper, chromium, iron, cobalt, and nickel precipitate. The fact that a catalyst is produced by substituting a heavy metal with an alkali metal fY at a pH in this specific range is reflected in U.S. Patent No. ,7
No. 00,605 is a new method.

On the other hand, an electroless plating method is known as a method for depositing heavy metal 4 on the surface of manganese dioxide. This method combines manganese dioxide with a sensitizer containing stannous chloride.
After being immersed in a liquid, the pieces are washed door-to-door with water, and then immersed in an activator solution containing palladium chloride and washed door-to-door with water.

Thereafter, the surface of the manganese dioxide particles can be coated with a heavy metal by treating with a necessary heavy metal electroless plating solution. This method has disadvantages 4 in that the electroless plating operation is complicated and the processing cost is high.

The inventors of the present invention have conducted various studies on oxidation catalysts containing manganese and copper (here, manganese refers to manganese and its compounds collectively, and also includes copper compounds). We have discovered a method in which a part of the manganese compound is replaced with copper at the same time when producing a coprecipitate. It was found that this method differs from the catalyst manufacturing method in which heavy metals are substituted with alkali metal delta mankanate in a specific PH range, and that the catalyst obtained by the simple manufacturing process has high oxidation catalytic activity at low temperatures.

Therefore, an object of the present invention is to provide an oxidation catalyst containing manganese and copper that has high oxidation activity at low temperatures. At the same time, as a result of examining the O5 decomposition performance at low temperatures using the catalyst according to the present invention, it was found that the catalyst had extremely excellent O3 decomposition performance.

Therefore, another object of the present invention is to provide an ozone decomposition catalyst containing manganese and copper that has excellent O8 decomposition performance at low temperatures. The catalyst containing manganese and copper according to the present invention is basically produced by adding an oxidizing agent to a mixed solution of a soluble salt of manganese and a soluble salt of copper, and then neutralizing or mixing with an alkaline solution containing permanganate. This is achieved by neutralizing the solution with the alkaline solution and then adding the entire oxidizing agent. The resulting product is amorphous according to X-ray diffraction analysis, and the product cannot be completely identified, but the present catalyst is characterized by its amorphous nature. Also, according to differential thermal analysis, it is known that it is a compound of manganese and copper whose weight gradually decreases by releasing water of crystallization up to about 500°C, but the chemical formula of the compound is unknown.

The catalyst of the present invention was found to have a total CO concentration of 2,500 ± 250 ppm in a smoke prevention test conducted based on the standards for fire evacuation protective equipment, etc. according to the test method described in Examples below.
The CO after passing through the catalyst is
When the concentration was measured, it was less than 1100pp, which was 350pp.
It was found that the performance far exceeded the above-mentioned standard, which set the acceptance standard as below p pm. 10,000 to 150 ppm of air,
Even if processed at a spatial velocity of 000HY-1, 0 of more than 90 inches
It was found that the O3 decomposition performance did not deteriorate even after a 500 hour durability test.

One preferred example of the method for producing the catalyst of the present invention, 11ζ, will be explained in detail below.

Soluble salts of manganese such as manganese nitrate, manganese sulfate, Zn chloride, etc. per 1 mol, preferably 0
．． An aqueous solution containing 1 to 0.3 mol of copper nitrate.

Copper soluble salts such as copper sulfate and copper chloride per 001 to 5
mol, preferably an aqueous solution containing 0.1 to 0.3 mol. This mixture? 0.01 to 0.5 mol of hydrogen peroxide as an oxidizing agent, preferably 0.1 to 0, per ff1lt;
Gradually add 2 moles. When all the hydrogen peroxide solution is added, a slight amount of bubbles will be generated.

Once this point is reached, add the alkali metal salt of permanganate to 0.15 mole of O8 per 1 part, preferably 0.05 to 0.
．． After making an aqueous solution containing 1 mol of potassium hydroxide or sodium hydroxide 'f:1, the above hydrogen peroxide solution was added to an alkaline solution mixed in an aqueous solution containing 1 to 10 mol, preferably 5 to 10 mol, of potassium hydroxide or sodium hydroxide 'f:1. When it is gradually added to the mixed solution, a blackish brown precipitate is formed and bubbles are suddenly generated. It is better for oxidation of the precipitate to end the addition while bubbles are being generated. The alkaline solution may be added while being heated or at room temperature. The obtained precipitate is sufficiently stirred and then left to stand, the supernatant liquid is removed by decantation, and the repulping and decantation are repeated two to three times with heated deionized water. Pl of the supernatant (9.
After it becomes 5 or less, preferably 9 or less, it is separated from house to house using a centrifuge. Once this state is reached, a manganese and copper containing product according to the invention is obtained, which can be
Dehydrate to half-dry state at the temperature after c@, and use activated carbon zeolite if necessary.

Adsorbents such as bentonite and activated alumina are added, and binders such as alumina sol and sodium silicate are added to the precipitate.
Add 5 to 15 parts by weight, preferably 5 to 15 parts by weight, based on the dry weight of 3 to 30 parts per part, and thoroughly homogenize, form into the required shape using a pelletizer, and heat at 100 to 150°C. After drying for several hours, a catalyst according to the invention is obtained.

): It is not necessary to exclude heavy metals other than manganese and copper in the catalyst of the present invention. For example, iron, cobalt,
Nickel, silver, rare earth elements, etc. may be present in the mixed solution as gold or as a compound thereof, or may be mixed with an adsorbent such as activated carbon or zeolite.

EXAMPLES Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto.

Example-1 Manga sulfate (MnSO, .OH, 0) 1,900g
Dissolve r in ion-exchanged water to make a liquid volume 'f of 50 t. Copper sulfate (α phantom 4, 5H, 0) 500 gr fDissolve in ion-exchanged water to make a liquid volume of 13 tons. Next, these solutions were mixed in their entirety at room temperature, and hydrogen peroxide solution (30%
Add 1 t of %.

Potassium permanganate (f(MnO4) 170 g
An alkaline solution mixed with a solution prepared by dissolving r in ion-exchanged water to make a liquid acid of 1°1 t and a solution prepared by dissolving caustic soda 10105O in ion-exchanged water to make a liquid amount of 3.5 t is added. After a precipitate is formed, the mixture is stirred and left to stand for about 1 hour. After the precipitate has settled, the supernatant liquid is separated, warm ion-exchanged water is added, the precipitate Th IJ valve is used, and the same operation is performed. When the pH of the supernatant drops below 95, it is separated using a centrifuge.

The obtained cookie was dried at 100 to 110°C for about 4 hours to a half-dry state, and 500g of alumina sol (10%) was added.
After addition, the mixture was kneaded using a Nigu machine, formed into pellets with a diameter of 1.5 pieces using a pelletizer, and dried at 1-50°C for 5 hours to obtain a product.

As a result of complete analysis of the obtained product, Mn: 57%, Cu
:12% and was amorphous.

Example-2 Precipitate obtained in the same manner as in Example-1, completely dried 1. Activated carbon 200g per 1,000g on dry basis
A manganese catalyst was obtained in the same manner as in Example 1 except that 600 gr of gr and alumina sol (io%) were added.

Test example-1 The catalyst performance test was conducted under the following conditions.

Fire prevention)) Based on the test methods and criteria for IE protective equipment, etc., the smoke collection box contains wood smoke and -carbon oxide concentration.
The smoke and gas concentrations in the input side smoke density meter are each 0.7±.
0.1 (attenuation coefficient), 2500±250 ppm
K ari 74 save money.

This smoke was passed through a test smoke mask with an airflow rate of 30t/-.
Measure the smoke concentration, carbon oxide concentration and ventilation resistance value.

In this test, the smoke concentration Q was 1/m or less, the carbon oxide concentration was 350 ppm or less, and the ventilation resistance was 50 mAq.
If the time is below 3 minutes or more, it is considered a pass.

The method for measuring catalyst performance is to place 100
A mixture of zeolite and activated carbon of equal strength is charged on top of the catalyst, so that the test gas enters from the zeolite side and passes through the catalyst. At this time, the gas concentration and ventilation resistance on the inlet and outlet sides of the gas were measured.

The test results are shown in Table-1. The results of commercially available fobucalide as a comparative catalyst are also listed in Table 1. Test Example 2 03 Decomposition Test 1 was carried out under the following conditions.

Example in which air mixed with 03 obtained from a 03 generator was humidified by passing it through water and filled into a cylindrical container with a diameter of 2 ONR.
1 minute and flowed through 10 mt of the pellet catalyst obtained in Example-2 at a flow rate of 1 to 3017 m, and 0.0 m in the mixed air before and after passing through the catalyst layer. The concentration was analyzed and the 03 decomposition performance was completely measured.

The test results are shown in Figures 1 and 2.

As is clear from the above results, the manganese catalyst of the present invention is extremely effective in removing carbon monoxide and decomposing ozone at low temperatures.

[Brief explanation of drawings]

Figures 1 and 2 are graphs showing ozone decomposition efficiency versus space velocity or test time. Patent applicant Mitsui Mining & Mining Co., Ltd. agent Patent attorney Shibu Mitsuishi (1 other person)

Claims (1)

[Claims] A manganese melting medium consisting of manganese and copper and their compounds, characterized in that an alkali solution containing an oxidizing agent and a permanganate is added to a solution of soluble salts of manganese and copper.