JPS6072977A - Oxidizing agent for carbon monoxide - Google Patents

Abstract

PURPOSE:To obtain an oxidizing agent which is highly active, can be inexpensively produced and can effectively exhibit CO-oxidizing activity even at room temp., by combining a Co compd. and a Lu compd. or an Ni compd. with MnO2. CONSTITUTION:Oanganese dioxide y combining a Co compd. and a Lu compd. or an Ni compd. with MnOruthenium compd. or a nickel compd. alone, or an aq. soln. of at least two members of them, and dried. The dry product is treated with a satd. aq. KMnO4 soln., washed and dried to obtain an oxidizing agent for carbon monoxide. Pref. the quantity of the cobalt compd., the ruthenium compd. or the nickel compd. to be carried is in the range of 0.1-20% (in terms of metal). When the oxidizing agent is powdery, a binder is added thereto and the mixture can be compression molded into the desired shape.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CO oxidizing agent that selectively oxidizes carbon monoxide (hereinafter referred to as CO) in a gas and converts it into non-toxic carbon dioxide (hereinafter referred to as CO).

CO, produced by the incomplete combustion of carbon compounds such as carbon and hydrocarbons, is one of the most toxic air polluting gases. CO has a strong binding force with hemoglobin in the blood, which plays the role of absorbing and transporting oxygen (02) <(0,
(200 to 300 times the binding force of CC), which causes high concentration CC toxicity in the human body, which can even lead to death. Furthermore, long-term exposure to low concentrations of CO is said to cause heart disease. For this reason, there are methods to prevent air pollution from automobile exhaust gas, indoor pollution from heating equipment exhaust gas and smoking, and methods to reduce the CO concentration in environmental gases for safety in the event of an explosion or fire in a mine. There is a strong desire for the establishment of

The CO removal methods that have been proposed so far include (1) adsorption with an adsorbent; (2) Absorb with absorption liquid. (3) Conversion to blue-free COt using an oxidizing agent or an oxidizing catalyst.

Methods for (1) include a method using a porphyrin metal complex as an adsorbent (Japanese Patent Publication No. 54-22951) and a method using a combination of activated carbon and molecular sheep (U.S. Pat. No. 3,658,069). The disadvantage is that the adsorption rate of CO is relatively slow, and the latter is also adsorbed and released at the same time.
qUp to 8, there is a drawback that Buddha 4 Todoroyu ξbemif> + -L.

As an example of the method (2), CO is absorbed into a toluene solution of cuprous chloride and aluminum chloride complex, and 2q is removed (West German Patent No. 1944405, German Patent No. 24).
14801) and a solution cleaning method using a copper ammine complex ion solution are known, but the former loses CO absorption activity due to trace amounts of moisture, and the latter has the disadvantage that copper ions are easily oxidized. This has the disadvantage that CO absorption activity is lost due to this, and as a result, both devices require large-scale equipment, which imposes many restrictions on use.

As an example of (3), the oxidation catalyst fobcalide, which is mainly composed of manganese dioxide and cupric oxide, has been known for a long time, and this catalyst has high CO2 even at room temperature or lower.
However, since it easily loses its activity due to trace amounts of moisture, it is inconvenient that it must be stored in a sealed container and that the gas to be treated must be completely dried before use.

On the other hand, many single metals or metal compounds are known as catalysts for oxidizing CO to COl, but most of them lose their activity at temperatures much higher than room temperature.
Moreover, it is easily deactivated by moisture in the gas.

A small amount of precious metals such as platinum and palladium have C at room temperature.
Although it has O oxidation activity and remains relatively stable and active against moisture, the activity itself is extremely low.

The object of the present invention is to create a new highly active CO oxidizing agent that is effective even at room temperature, where CO oxidation is active, and uses a compound that is cheaper and easier to manufacture than platinum, palladium, etc.

As a result of various studies on CO oxidizing agents that can achieve this purpose, the present inventors impregnated manganese dioxide with a cobalt compound, a ruthenium compound, or a di-Kel compound, and used a potassium permanganate (hereinafter referred to as KMn04) aqueous solution. It has been found that the oxidizing agent obtained by treatment with oxidizing agent is well suited for the purpose.

Compared to platinum and palladium, beni, kel, and cobalt are cheap, and ruthenium is relatively cheap, and although the precious metal content ratio in the ore is low, demand is low, so there is no concern about supply. Although manganese dioxide has CO oxidation capacity, it is very low at room temperature. Also, cobalt,
When ruthenium or di-Kel compounds are used alone, their COriI-forming activity is very low.

The present inventors have demonstrated that the CO oxidation activity at room temperature can be increased by combining manganese dioxide with cobalt compounds, ruthenium compounds, 2- or 2-higher compounds such as chel compounds, which had low activity when used alone. The present invention was completed after discovering that there is an effect of increasing the amount of water.

That is, the present invention is characterized by comprising a compound of one or two higher classes selected from the group of compounds containing Group 8 elements of the periodic table consisting of cobalt compounds, ruthenium compounds, di- and Kel compounds, and manganese dioxide. The present invention provides a carbon monoxide oxidizing agent.

Manganese dioxide can be prepared by the electrolytic oxidation method of divalent manganese salts or by the method of preparing divalent manganese salts and KMn 04 under alkaline conditions (J, Attenbrough et al. J, Chem, 8o
c, 1094 (1952)) *method prepared under nitric acid acidity (J, Tolman British Patent No. 1315374) and method prepared from neutral solution (s, Ball Biochem,
J 42516 (1948)), but the manganese dioxide used in the present invention may be obtained from any of these methods.

The oxidizing agent according to the present invention is a cobalt compound, Ruthenium I) on NnOt which has been previously bolted (GIE) by the above method. It is obtained by impregnating a single aqueous solution or a mixture of two or more of the compound or the Kel compound, drying, and then treating it with a saturated KMnO4 aqueous solution, washing, and drying. The amount of cobalt compound, ruthenium compound, or di-kel compound supported may be any amount, but it is most preferably in the range of 0.1 to 20% in terms of these metals. When the oxidizing agent is a powder, it can be used in a suitable form by adding a binder such as C or by compression molding.

The oxidizing agent thus obtained can effectively convert CO to CO at room temperature.
Applications include gas masks for CO removal, CO reducing agents for air cleaners, and cigarettes for low-range CO in smoke. Examples include filter holders and cigarette filter fillers.

The present invention will be described in detail below using Examples.

Example 1) 5Of of manganese nitrate hexahydrate was dissolved in 300 of distilled water, and 5Of of concentrated nitric acid was added thereto. Separately 5
KMnO4 of No. 01 was dissolved in 2 tons of distilled water, and while stirring this solution, the previously prepared nitric acid acidic manganese nitrate aqueous solution was gradually added. The mixture was allowed to stand for about 10 minutes with stirring, and the activated manganese dioxide produced was washed by a decanting method, and further washed with suction filtration until the V liquid became almost colorless. Next, it was dried at 110°C overnight, and the obtained activated manganese dioxide in the form of 25f blocks was crushed and sieved. Take activated manganese dioxide with a particle size of 20/60 mm, 5 Tl9
CoCL, 6H, 0/* solution 8*tll (soaked, hI
After water was distilled off under C pressure, it was dried at 110°C overnight. The cobalt chloride-supported active manganese dioxide obtained in this way was
Further, it was immersed in a saturated I (MnO, aqueous solution lO-), left for 10 minutes, separated, and washed with distilled water until the pink color of permanganate ions was no longer observed.Next, it was dried at 110°C overnight, and the metal Activated manganese dioxide carrying cobalt of 1.0% by weight was obtained in terms of 1.0% by weight.By using the same procedure as this, metallic cobalt was prepared by 0.02.0.2.2.0,
4.0, 6.0, 8.0, 10.0, 12.0, 14.
Q and other agents supporting OwtKaip≠Pult were prepared. Using 200 μl of each of these oxidizing agents, the CO removal rate was measured according to the following procedure. ■Fill the oxidizing agent into a glass tube and press both ends of the filling with glass wool. ■While flowing helium as a carrier gas through this glass tube, the reaction gas (COs%
, 0.4%, CH44%.

A pulse of 87% helium was applied for 10 d at room temperature (22° C.). ■The gas that has passed through the glass tube is guided directly to the gas cylinder to analyze the gas components.

The results are shown in FXJ 1, and the average CO reduction rate of each oxidizing agent is shown in Fig. 2. Cobalt addition amount 2.0 to 8.0 wt
A range of oxidants were highly active in CO oxidation, and they removed an average of 90% of CO.

Example 2) Commercially available Mn0 obtained by m-deoxidation method
The t4f was immersed in 25-g water in which 100 kg of cobalt chloride hexahydrate was dissolved, and the water was distilled off under reduced pressure. Following the same procedure as described in Example 1, KMnO4 aqueous solution treatment, cleaning,
After drying, 200 μm of the obtained oxidizing agent was subjected to a pulse test. As shown in Table 1KR, commercially available MnO
Even when x was used, the obtained oxidizing agent showed high CO oxidation activity.

Table 1 Example 3) 5" of activated manganese dioxide obtained in Example 1
f RuC4/d 4.52-, and water was distilled off under reduced pressure. Next, an oxidizing agent was prepared in the same manner as in Example 1 to obtain activated manganese dioxide carrying 1, Q wt% of ruthenium. Similarly, 0.02~'l
5. Several activated manganese dioxides loaded with ruthenium in the Q wt% range were prepared. 20 each of the obtained oxidizing agents
When we conducted the Nox test on 0q, the result was the third
It became as shown in Figure 4. The optimum ruthenium addition rate for CO oxidation is 12.0 to N4.0w1%, and the CO
The husband removal rate was approximately 40%.

Example 4) The activated manganese dioxide obtained in Example 1 and a 0.02 to 14.9 w15 aqueous solution of dichloride Kel were added and treated according to the procedure described in Example 1. A seed oxidizer was obtained.

200 q of each of these oxidizers were subjected to a pulse test, and the CO reduction rates shown in FIGS. 5 and 6 were obtained. 92, suitable for CO oxidation, Kel addition rate is 4.0-8. Owt%, especially 60wt
% catalyst had a CO removal rate of 35%.

Example 5) Dissolve 2Of anhydrous manganese sulfate in 100E of water and add to it with stirring 1(H')<MnO
300 mj of sodium hydroxide dissolved in 4 and 51!
of distilled water was gradually added. The resulting black-brown precipitate IQ was separated by suction through a 1'' I filter, and further washed with distilled water until the I' liquid became almost colorless.

Next, this was dried at 110° C. overnight to obtain active manganese dioxide powder. Take lt out of this and 5 mf C0C
L,, 6) After soaking in 16 ml of I207, the sample was treated in the same manner as in Example 1 to obtain an oxidizing agent containing 2.0 wt% cobalt. Table 2 shows the results of a pulse test performed on this oxidizing agent at 200 mf.

Table 2 Practical LffiM Examples 6) Examples 1-5 describe carbon monoxide oxidizers prepared from various manganese dioxides and chlorides of cobalt, di, chel, or ruthenium. However, the cobalt, nickel and ruthenium compounds used are not limited to chlorides, but may also be nitrates, sulfates, acetates or other arbitrary salts. Therefore, an oxidizing agent was prepared from the activated manganese dioxide lf obtained in Example 1 and compounds other than the chlorides of cobalt, nickel, and ruthenium by the same procedure as described in Example 1, and the oxidizing agent was oxidized using 200 mF for each. The activity was examined. The results are shown in Table 3.

In addition, compounds other than those listed in Table 3 (e.g. Cocoa'7
Hs O, Co (CHs Coo)!・4Hs O,
Ni (Noj) 禦・6Ht OrNISOa・6H
, O), similar Co removal activity was observed.

Table 3 From the above examples, it was demonstrated that the cobalt compound rutheni has the ability to efficiently oxidize CO in the gas phase at room temperature.

[Brief explanation of drawings]

Figure 1 is a graph of pulse test results for cobalt-activated manganese dioxide, Figure 2 is a graph of average CO reduction rate for cobalt-activated manganese dioxide, and Figure 3 is a graph of pulse test results for ruthenium-activated manganese dioxide. Fig. 4 is a graph of the average CO reduction rate of ruthenium-activated manganese dioxide, Fig. 5 is a graph of the pulse test results of nickel-activated manganese dioxide, and Fig. 6 is a graph of the average CO reduction rate of ruthenium-activated manganese dioxide. It is a graph of average CO reduction rate. Pulse (times) Figure 1 Cobalt addition rate fwl'/at Figure 2 Pulse 7,, (times) Rate 3 Figure Ruthenicum pressure ml list 1wj%1 Figure 4 I Malus (times) Figure 5 Figure 2 - Nokel) r > Year 1w + %) Figure 6 Procedures Correction Old (Method) % Formula % 3. Relationship with famous event to be corrected ``1. Number 1 Name (4
56) Japan exclusive public! 1 Representative Director: Minoru Nagaoka 4, Designated Agent (1, Address: 2-2-1 Toramon, Minato-ku, Tokyo 1Mj Wa 5)
January 9, 3111 (Delivery date) 6. Details to be amended V; 7. The full text of the written statement has been amended (no changes to the contents).

Claims (1)

[Claims] 1. Cobalt compound, ruthenium compound, 2. A carbon monoxide oxidizing agent characterized by comprising a first or second class higher compound selected from the group of compounds containing Group 8 elements of the periodic table consisting of Kel compounds and manganese dioxide.