KR101277676B1 - A manufacturing method of ruthenium oxide used ultrasonic and direct reduction - Google Patents

Abstract

The present invention has been attracting attention in the field of automobiles and electronic components, which is used as a synthetic reaction catalyst having excellent catalytic activity as metal oxides and complexes, and is effective in resistance materials, various sensor materials, capacitor electrode materials and electromagnetic shielding materials. As environmental issues are raised, the use of electrode materials for the treatment of wastewater is increasing. The present invention relates to a method for producing ruthenium dioxide (RuO ₂ ). The present invention relates to a manufacturing method that can be easily controlled by the present invention and is suitable for mass production. The present invention uses a metal ruthenium as a starting material and provides a manufacturing method comprising a distillation step using a control of impurities generated during the preparation of a ruthenium compound, a particle control step through ultrasonic waves, and a reduction to a tetravalent ruthenium compound.

   Ruthenium oxide, ruthenium dioxide, metal ruthenium, ultrasonic wave, direct reduction

Description

A manufacturing method of ruthenium oxide used ultrasonic and direct reduction}

The present invention relates to a manufacturing method of ruthenium dioxide (RuO ₂ ), in particular by making it manufactured by firing at a high temperature of 400 ℃ or more to make it easy to control the difficulty of particle control by the reduction of alcohols, manufacturing method suitable for mass production It is about.

In order to prepare ruthenium dioxide (RuO ₂ ), a solution of ruthenium chloride (RuCl ₃ xH ₂ O) as a starting material, neutralized it with ammonia water, the fine particles of ruthenium hydroxide were formed, and the obtained fine particles were washed and dried to obtain ruthenium dioxide ( RuO ₂ ) was getting powder. (JP 1990-88432)

      As a method of pyrolysis, nitric acid was added to an aqueous ruthenium chloride solution and evaporated to dryness, and then pyrolyzed at 350 ° C to 370 ° C, and then maintained at 500 ° C to 550 ° C to obtain ruthenium dioxide powder. (GC Bond. Etal Proc. Chem. Soc. 1964, 398)

Further, a method of reducing K ₂ RuO ₄ solution to methanol as a starting material to obtain ruthenium hydroxide, washing the obtained ruthenium hydroxide to remove impurities, and pyrolyzing at 600 ° C. to obtain ruthenium dioxide (JP 59-50032), K ₂ RuO ₄ solution and then reduced with methanol to obtain ruthenium hydroxide, obtaining the ruthenium dioxide after 800 ℃ calcination followed by the addition of K, Na ions in the obtained ruthenium hydroxide (JP1996-268722), hexachloro-ruthenate and potassium (K ₂ RuCl ₆ ), And a method of obtaining ruthenium dioxide by firing at 800 ° C. from potassium pentachlororuthenate (K ₄ Ru ₂ OCl ₁₀ H ₂ O) and potassium pentachlororuthenate (K ₂ RuCl ₅ ) (JP 2007-302497). Conventional methods describe the easy synthesis of ruthenium dioxide through changes in starting materials, but do not describe yield. This is due to the volatilization of ruthenium tetraoxide (RuO ₄ ) by heat during the ruthenium dioxide formation process is difficult to control. In addition, to remove impurities (K, Na) is washed after the formation of ruthenium hydroxide, which is difficult to remove the impurities and yields due to the washing of the fine powder. In addition, there is a problem that it is difficult to control the aggregation of the particles to obtain ruthenium dioxide through high-temperature firing after the removal of impurities.

       SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and when the temperature, concentration and base loading rate of the reaction solution, pH, amount of alcohol, Ultra-sonic, etc. are comprehensively controlled, high purity fine ruthenium dioxide powder can be massed in high yield. It has been found through a number of experiments and examples that it can be produced to reach the present invention.

      Mass production of high purity ruthenium dioxide requires a method of removing the existing washing process and a more convenient and faster manufacturing method to obtain fine powder. Therefore, the existing washing process was directly oxidized and distilled using the reaction with alcohol, and the method of adding K and Na ions needed to prepare fine ruthenium dioxide was added by using Ultra-sonic. Contamination of impurities by elements could be prevented, and the washing process could also be removed. In addition, it was possible to produce ruthenium dioxide at a low temperature rather than a high temperature.

      Therefore, the method for producing a high purity, fine ruthenium dioxide powder of the present invention, the patent is prepared by oxidizing through the firing using the patent JP1996-3207070 prepared by oxidizing through the firing using ruthenium nitrate and potassium nucleochloro ruthenate. Compared with JP2007-302497 and patent JP1996-268722, which is made by removing rubbing and rubbing of ruthenium hydroxide after reducing it in methanol using ruthenium potassium tetrachloride and directly by using ozone gas, The reaction can be synthesized at low cost for short reaction time by controlling the purity, eliminating the washing process, and increasing the dispersibility using Ultra-sonic. That is, it has the advantage of being suitable for mass production.

      Hereinafter, the present invention will be described in more detail.

     In order to achieve the above technical problem, the present invention comprises a distillation step used to form a ruthenium oxide by sodium hypochlorite using a metal ruthenium precursor and then to purify it, synthesizing ruthenium dioxide using an alcohol solvent and And removing the alcohol solvent using a vacuum dryer to prepare a ruthenium dioxide powder.

      First, a caustic soda and potassium hydroxide solution (first solution) of 0.2 to 10 M is added to the metal ruthenium for pH control. Next, sodium hypochlorite is added to the first solution in an amount of 100 to 600% of the metal ruthenium at a rate of 0.2 to 1 g / sec to maintain the reaction temperature at 0 to 25 ° C (when the reaction temperature is 0 ° C or less). It is not completely dissolved, and if it is 25 ° C. or higher, ruthenium tetraoxide is generated.

      20 to 100 ml of 1-5 L / min ozone and 1-5 L / min nitric acid gas are added to the second solution to oxidize ruthenium tetraoxide (but the reaction temperature must be maintained at 50-90 ° C.). . At this time, it is desirable to maximize the generation of ruthenium tetraoxide through the oxidation and reaction temperature by ozone.

    Next, the ruthenium tetraoxide produced above is preferably reduced to ruthenium dioxide using an alcohol solvent (methanol, ethanol, propanol, iso-propanol, buthanol, pentanol, hexanol, hepthanol, etc.). At this time, it is preferable to maintain 50 to 100 ft / s to use Ultra-sonic to increase the catalytic role and dispersibility of the reaction (less than 50ft / s has no effect on the dispersibility, more than 100ft / s agglomerates due to high temperature) This happens).

      In addition, the step of drying the remaining ruthenium dioxide powder from the ruthenium dioxide solution filter and the remaining ruthenium dioxide powder in a vacuum dryer at 50 ~ 150 ℃ (drying temperature is longer than 50 ℃ takes a long time, when the drying temperature is 150 ℃ or more Ruthenium dioxide is aggregated).

      According to the present invention, the reaction yield is high, the reaction time is short, and there is an effect of mass production of ruthenium oxide having excellent purity.

      Hereinafter, the present invention will be described in more detail.

      In the method for producing high purity ruthenium chloride according to the present invention, for mass synthesis

Precursor was used as metal ruthenium and must be completely dissolved by minimizing loss through control of reaction concentration and temperature. The dissolved liquid is oxidized to ruthenium tetraoxide through the reaction of a mixed gas of ozone and nitrogen. At this time, the temperature is raised to 50 ~ 90 ℃ to increase the reactivity. Since the boiling point of the ruthenium tetraoxide to be produced is 40 ℃, the reaction yield can be increased by vaporizing the ruthenium tetraoxide produced through the elevated temperature.

     The vaporized ruthenium tetraoxide is reacted with an alcohol solvent (methanol, ethanol, propanol, iso-propanol, buthanol, pentanol, hexanol, hepthanol, etc.) to prepare ruthenium dioxide. In this case, since the reaction between the gas phase and the liquid phase, the surface area of the gas phase can be increased by using ultra-sonic to increase the reactivity. In addition, the aggregation of the produced ruthenium dioxide is a controllable method. In addition, the method is characterized in that the ruthenium dioxide powder is vacuum dried after filtration of the solution to treat a large amount in a short time.

      The manufacturing method of the present invention is shown in FIG. 1 as a process example.

     1 shows a flowchart of a manufacturing process of ruthenium dioxide according to the present invention. A manufacturing method is demonstrated with reference to FIG. First, ruthenium chloride is prepared by using metal ruthenium as a raw material. A first solution (caustic soda or potassium hydroxide dissolved 0.2-10M) was prepared (S1) and metal ruthenium was added (S2), and sodium hypochlorite was added to the first solution at a rate of 0.2-1 g per second to sodium (or potassium) ruthenate is prepared and completely dissolved. (S3) The reaction temperature of the solution is characterized in that it is properly adjusted to be maintained at 0 ~ 25 ℃. After aging for 1 to 7 hours, the reaction solution is oxidized. (S4)

      At this time, it is preferable to use an oxidant gas mixture of ozone and nitrogen. The ruthenium tetraoxide is then reacted with an alcohol solvent (methanol, ethanol, propanol, iso-propanol, buthanol, pentanol, hexanol, hepthanol, etc.) to produce a ruthenium dioxide solution. At this time, by adding ultra-sonic to increase the reactivity, it is characterized by controlling the particle size of the powder produced. After the solution is removed, the ruthenium dioxide powder is vacuum dried at 50 to 150 ° C. (S7)

      Hereinafter, the embodiment of the present invention will be described in more detail. However, the following examples are illustrative of the present invention, and the content of the present invention is not limited by the examples.

Example 1

First, dissolve 17 g of caustic soda (or potassium hydroxide) (98%, Aldrich) in 40 ml of water in a 2 L reaction vessel and add 20 g of metal ruthenium. The temperature of the solution was maintained at 20 ° C, 268 g of sodium hypochlorite solution was added at a rate of 4.2 ml / min, and stirred to dissolve the metal ruthenium. This solution in ruthenium salt was aged for 2 hours.

      After aging, 2 L / min ozone and nitrogen gas were added to the solution as an oxidizing agent, and then aged at 80 ° C. for 2 hours. The oxidized ruthenium tetraoxide gas was reacted with ethanol. At this time, ultra-sonic was added at 80ft / s to disperse ruthenium dioxide. After filtering the slurry solution, the upper powder was vacuum dried at 80 deg. C to obtain 26 g of ruthenium dioxide.

[Example 2]

      Dissolve 85 g (98%, Aldrich) of caustic soda (or potassium hydroxide) in 200 ml of water in a 10 L beaker and add 100 g of metal ruthenium. The temperature of the solution was maintained at 20 ° C., 1340 g of sodium hypochlorite solution was added at a rate of 4.2 ml / min, and stirred to dissolve the metal ruthenium. This solution in ruthenium salt state was aged for 2 hours. After aging, 2L / min ozone and nitrogen gas were added to the solution as an oxidizing agent, and then aged at 80 ° C for 2 hours. The oxidized ruthenium tetraoxide gas was reacted with ethanol. At this time, ultra-sonic was added at 80 ft / s to disperse ruthenium dioxide. After filtering the slurry liquid, the upper powder was vacuum dried at 80 deg. C to obtain 130 g of this ruthenium oxide.

Comparative Example 1

The K ₂ RuO ₄ solution was reduced with methanol, the reduced ruthenium oxide hydrate was filtered and washed to remove impurities, and then calcined at 600 ° C. for 2 hours to obtain a ruthenium dioxide powder.

Comparative Example 2

Potassium ruthenate chloride (Aldrich) with a concentration of 17 wt% of ruthenium, a mixture of potassium hexachlorothenate (K ₂ RuCl ₆ ) and pentachloro ruthenate (K ₄ Ru ₂ OCl ₁₀ H ₂ O), was used as a starting material. did.

10 g of the potassium ruthenate chloride was placed in an alumina container and calcined in a tubular furnace. In this firing condition, the firing temperature was 800 ° C., the temperature increase rate was 20 ° C./min, and the holding time was 1 hour. As the firing atmosphere, air was flowed at a flow rate of 15 L / min from the start of the temperature rise to the end of the cooling to form an oxidizing atmosphere.

       The calcined material was poured into 300 ml of pure water, stirred for 10 minutes with an ultrasonic cleaner and filtered. Pure water was added, stirred and filtered twice, and then dried at 90 ° C. for 10 hours using a hot air dryer.

scale Ultra-sonic Granularity Reaction time yield water Example 1 Ru 20g 80 ft / s 20 nm 6 hours 99% 99.99% Example 2 Ru 100g 80 ft / s 20 nm 8 hours 99% 99.99% Comparative Example 1 Ru 10g 0 ft / s 45nm 33 hours 99% 99.9% Comparative Example 2 Ru 1.7g 80 ft / s 77 nm 33 hours 73% 99.9%

      Figure 1 shows a flow chart of the manufacturing process of ruthenium oxide water according to the direct reduction and ultrasonic waves of the present invention.

Claims (4)

       In the method for producing a high purity ruthenium oxide compound,       Injecting metal ruthenium into a first solution in which caustic soda or potassium hydroxide is dissolved;       Adding sodium hypochlorite to the first solution to generate a ruthenium oxide salt to generate a second solution;       Maintaining the temperature at 50 ° C. to 90 ° C., oxidizing the second solution with 1 to 5 L / mim of ozone and 1 to 5 L / min of nitrogen gas to oxidize ruthenium tetraoxide;       Adding an alcohol solvent to the ruthenium tetraoxide and reducing the ruthenium oxide while controlling the aggregation using ultrasonic waves of 50-100 ft / s;        Filtering the ruthenium oxide solution to obtain ruthenium oxide powder;       Vacuum drying the ruthenium oxide powder; Method for producing a high purity ruthenium oxide compound comprising a.        The method of claim 1,       The caustic soda or potassium hydroxide is a method for producing a high purity ruthenium oxide compound, characterized in that 1 ~ 10M dissolved.        3. The method of claim 2,       The sodium hypochlorite is added in an amount of 300 to 600% of the metal ruthenium, at a rate of 0.2 to 1 g / sec, and a reaction temperature is maintained at 0 to 25 ° C. A method for producing a high purity ruthenium oxide compound. delete

Images