Preparation method of ruthenium nitrosyl nitrate

Abstract

The invention provides a preparation method of ruthenium nitrosyl nitrate, and relates to the technical field of precious metal compound preparation. The preparation method of ruthenium nitrosyl nitrate provided by the invention comprises the following steps: mixing an organic ruthenium complex and an oxidizing agent, and carrying out oxidation treatment to obtain a ruthenium nitrate solution; the oxidizing agent is a nitric acid solution and ozone; and carrying out nitrosylation on the ruthenium nitrate solution in an NO atmosphere to obtain the ruthenium nitrosyl nitrate. According to the method, the organic ruthenium complex is subjected to oxidation treatment, organic ligands in the organic ruthenium complex are oxidized into water and carbon dioxide, ruthenium ions and nitrate radicals are combined into ruthenium nitrate, NO is introduced into the ruthenium nitrate to introduce nitrosyl, halogen ions and other metal ions are not introduced in the preparation process, a subsequent impurity removal step is not needed, and the yield is high. The obtained ruthenium nitrosyl nitrate is high in purity, the yield reaches 100%, and the method is suitable for industrial production of ruthenium nitrosyl nitrate.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of precious metal compounds, and in particular relates to a method for preparing ruthenium nitrosyl nitrate. Background Art

[0002] The precious metal ruthenium has important applications in the fields of electrode catalytic materials for the chlor-alkali industry, ammonia synthesis catalysts, ammonia decomposition catalysts and hydrogenation reaction catalysts. The preparation of these catalytic materials involves the introduction of the active component ruthenium, which is introduced through ruthenium precursor compounds. So far, the precursors used to prepare supported ruthenium catalysts mainly include hydrated ruthenium trichloride (RuCl3·nH2O), ruthenium nitrosyl nitrate (Ru(NO)(NO3)3), ruthenium acetylacetonate (Ru(acac)3) and triruthenium dodecacarbonyl (Ru3(CO) 12 ) and so on. Among the various precursor compounds of ruthenium, RuCl3·nH2O is the most common ruthenium compound. It is stable, cheap, soluble in water and some organic solvents, and is widely used in the preparation of supported ruthenium catalysts. However, since this active precursor contains a large amount of chloride ions, the chloride ions remaining on the catalyst cannot be completely removed during the catalyst preparation process, which has a certain inhibitory effect on the catalytic performance and may even cause catalyst poisoning. Nitrate-based ruthenium precursors such as ruthenium nitrate solution and ruthenium nitrosyl nitrate, especially ruthenium nitrosyl nitrate, are recognized as ideal precursors for the preparation of ruthenium-based catalytic materials, but their synthesis technology is difficult and the cost is high, which also hinders their application in related fields.

[0003] With the development of industrial technology, higher requirements are placed on the performance of ruthenium electrode materials and supported ruthenium catalysts. It is very necessary to overcome the key technology of industrial preparation of ruthenium nitrosyl nitrate and realize the industrial production of low-cost ruthenium nitrosyl nitrate to meet the needs of related industries. In view of this, the industry and academia have spent a lot of energy on the batch preparation technology of ruthenium nitrosyl nitrate, mainly including oxidative distillation-nitric acid absorption method, silver salt dechlorination method and precipitation conversion method.

[0004] Wherein, during the oxidation distillation-nitric acid absorption method, the generated ruthenium tetroxide and nitric acid belong to strong oxidants, and a reducing agent needs to be added during the absorption process. If improper control is performed, a strong oxidant and a reducing agent are mixed and a violent explosion easily occurs; and ruthenium tetroxide gas is toxic, and it needs to be absorbed completely through multi-stage absorption, which is not suitable for the industrial production of ruthenium nitrate; the silver salt dechlorination method uses expensive silver salts, resulting in a high production cost of ruthenium nitrate. At the same time, while ensuring that chloride ions are completely removed, the silver ion content will be high, and the generated silver chloride will have a strong adsorption capacity for the product, which will result in a reduced yield, and is also not suitable for the industrial production of ruthenium nitrate; the precipitation conversion method produces precipitation filtration and is extremely difficult, and alkali metal ions and chloride ions are difficult to completely remove. Therefore, the above preparation methods all have the defect of being unsuitable for the industrial production of ruthenium nitrate. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing ruthenium nitrosyl nitrate. The present invention uses an organic ruthenium complex precursor as a raw material, performs a one-step oxidation, and then uses NO gas to introduce a nitrosyl group to prepare ruthenium nitrate. The preparation method is simple, no impurities are introduced during the preparation process, no impurity by-products are generated, and no subsequent impurity removal step is required, so the ruthenium nitrate is suitable for industrial production.

[0006] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0007] A method for preparing ruthenium nitrosyl nitrate comprises the following steps:

[0008] The organic ruthenium complex and an oxidant are mixed and subjected to oxidation treatment to obtain a ruthenium nitrate solution; the oxidant is a nitric acid solution and ozone;

[0009] The ruthenium nitrate solution is nitrosylated in a NO atmosphere to obtain the nitrosyl ruthenium nitrate.

[0010] Preferably, the organic ruthenium complex comprises one or more of ruthenium oxalate, ruthenium acetate and ruthenium acetylacetonate.

[0011] Preferably, the concentration of the nitric acid solution is 6-8 mol / L; the solid-liquid ratio of the organic ruthenium complex and the nitric acid solution is 5000 g:3-4 L.

[0012] Preferably, the oxidation treatment is carried out at a temperature of 90 to 95° C. and for a time of 1 to 2 hours.

[0013] Preferably, the ozone is introduced for 1 to 2 hours during the oxidation treatment.

[0014] Preferably, the nitrosylation temperature is 70-90° C. and the time is 10-20 min.

[0015] Preferably, the tail gas obtained by the oxidation treatment is absorbed by an alkaline reagent.

[0016] Preferably, the alkaline agent includes one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide.

[0017] The present invention provides a method for preparing ruthenium nitrate nitrate, comprising the following steps: mixing an organic ruthenium complex and an oxidant, performing oxidation treatment, and obtaining a ruthenium nitrate solution; the oxidant is a nitric acid solution and ozone; and nitrosylating the ruthenium nitrate solution in a NO atmosphere to obtain the ruthenium nitrate nitrate. The present invention performs oxidation treatment on the organic ruthenium complex, wherein the organic ligand in the organic ruthenium complex is oxidized into water and carbon dioxide, and the ruthenium ion and the nitrate ion are combined into ruthenium nitrate, and then NO is introduced into the ruthenium nitrate to introduce nitrosyl groups. No halogen ions and other metal ions are introduced in the preparation process, and no subsequent impurity removal step is required. The obtained ruthenium nitrate nitrate has high purity and a yield of 100%, and is suitable for the industrial production of ruthenium nitrate nitrate.

[0018] In addition, the tail gas obtained after oxidation treatment in the present invention is nitrogen oxides and carbon dioxide, which are absorbed and treated with alkaline reagents to achieve zero emission of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] Figure 1 The present invention is a flow chart for the preparation of ruthenium nitrosyl nitrate. DETAILED DESCRIPTION

[0021] The present invention provides a method for preparing ruthenium nitrosyl nitrate, comprising the following steps:

[0022] The organic ruthenium complex and an oxidant are mixed and subjected to oxidation treatment to obtain a ruthenium nitrate solution; the oxidant is a nitric acid solution and ozone;

[0023] The ruthenium nitrate solution is nitrosylated in a NO atmosphere to obtain the nitrosyl ruthenium nitrate.

[0024] In the present invention, unless otherwise specified, all preparation raw materials are preferably commercially available products well known to those skilled in the art.

[0025] The present invention mixes an organic ruthenium complex and an oxidant, performs an oxidation treatment, and obtains a ruthenium nitrate solution. In the present invention, the mass content of ruthenium in the organic ruthenium complex is 25-39%, and in a specific embodiment, it can be 25.35%, 27.45% or 38.57%.

[0026] In the present invention, the oxidant is a nitric acid solution and ozone; the concentration of the nitric acid solution is 6 to 8 mol / L, and in a specific embodiment, it can be 6.5 mol / L or 7 mol / L; the solid-liquid ratio of the organic ruthenium complex and the nitric acid solution is 5000 g:3 to 4 L, and in a specific embodiment, it can be 5000 g:3.5 L or 5000 g:3.8 L.

[0027] In the present invention, the ozone is introduced for 1 to 2 hours, and in a specific embodiment, it can be 1 hour, 1.5 hours or 2 hours. The present invention has no limitation on the concentration of the ozone, and also has no limitation on the pressure when the ozone is introduced.

[0028] In the present invention, the organic ruthenium complex, nitric acid and oxidant are mixed by stirring; the present invention has no special limitation on the stirring rate. In the present invention, the temperature of the oxidation treatment is 90-95°C, and in a specific embodiment, it can be 92°C, 93°C or 94°C; the time is 1-2h, and in a specific embodiment, it can be 1.5h or 1.8h. The present invention oxidizes the organic ruthenium complex, and the organic ligand in the organic ruthenium complex is oxidized into water and carbon dioxide, and the ruthenium ion and nitrate are combined to form ruthenium nitrate.

[0029] In the present invention, the tail gas obtained by the oxidation treatment is absorbed by an alkaline reagent; the tail gas is nitrogen oxides and carbon dioxide; the alkaline reagent includes one or more of sodium hydroxide, sodium hydroxide and potassium hydroxide, and in a specific embodiment, it can be sodium hydroxide; the sodium hydroxide is used in the form of a sodium hydroxide solution; the concentration of the sodium hydroxide solution in the present invention is 10-30%, and in a specific embodiment, it can be 15%, 20% or 25%.

[0030] After obtaining the ruthenium nitrate solution, the present invention nitrosylates the ruthenium nitrate solution in a NO atmosphere to obtain the nitrosyl ruthenium nitrate. In the present invention, the nitrosylation temperature is 70 to 90° C., and in a specific embodiment, it can be 75° C., 80° C. or 85° C.; the time is 10 to 20 minutes, and in a specific embodiment, it can be 15 minutes or 18 minutes. The present invention has no special restrictions on the concentration and amount of NO. In a specific embodiment of the present invention, an excess of NO is used for nitrosylation.

[0031] In the present invention, the nitrosylation further comprises concentrating the obtained product system; in the present invention, the obtained product system is concentrated to dryness.

[0032] In order to further illustrate the present invention, the preparation method of ruthenium nitrosyl nitrate provided by the present invention is described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0033] Example 1

[0034] according to Figure 1 The flow chart shown is used to prepare ruthenium nitrate nitrosyl, and the specific steps are:

[0035] 5000 g of ruthenium oxalate (ruthenium: 27.45 wt%) was weighed and placed in a 2-liter three-necked round-bottom flask equipped with a condenser. Under stirring, 3 L of 8 mol / L concentrated nitric acid was added dropwise, and ozone was introduced at the same time. The mixture was heated under reflux at 90° C. for 1 h and concentrated to obtain a ruthenium nitrate solution. The obtained tail gas was absorbed by a 30 wt% sodium hydroxide solution.

[0036] NO was introduced into the above ruthenium nitrate solution, and the reaction was continued by heating at 70°C for 10 min. The solution was concentrated to obtain a ruthenium nitrate solution, and the solution was further concentrated to dryness to obtain 3699.46 g of ruthenium nitrate solid with a conversion rate of 100% and a ruthenium content of 37.10 wt%.

[0037] The structure of the obtained ruthenium nitrosyl nitrate was characterized by infrared spectroscopy, the content of impurity metals in the product was determined by ICP, and the content of chloride ions in the ruthenium nitrosyl nitrate was determined by ion chromatography.

[0038] Among them, infrared spectrum (IR), KBr pressed tablet: 1924.09 (s, vRu-NO); metal impurity mass content and chloride ion content, the results are shown in Table 1:

[0039] Table 1 Test results of ruthenium nitrosyl nitrate obtained in Example 1

[0040] Pb (%) <0.001 Mg (%) <0.001 Rh (%) <0.001 Fe (%) 0.002 K(％) <0.001 Ir(％) <0.001 Cu (%) <0.001 Ag (%) <0.001 Au (%) <0.001 Na (%) <0.001 Pt (%) 0.002 Mn (%) <0.001 Ca (%) <0.001 Pd (%) <0.001 Co (%) <0.001 Ni (%) <0.001 Ti (%) <0.001 Si (%) <0.001 Zn (%) <0.001 Mo (%) <0.001 Cl (ppm) 1.3

[0041] Example 2

[0042] 5000 g of ruthenium acetate (ruthenium: 38.57 wt%) was weighed and placed in a 2-liter three-necked round-bottom flask equipped with a condenser. Under stirring, 3 L of 8 mol / L concentrated nitric acid was added dropwise, and ozone was introduced at the same time. The mixture was heated at 95°C for 1.5 h and concentrated to obtain a ruthenium nitrate solution. The obtained tail gas was absorbed by a 20 wt% sodium hydroxide solution.

[0043] NO was introduced into the above ruthenium nitrate solution, and the reaction was continued under reflux at 80°C for 15 min. The solution was concentrated to obtain a ruthenium nitrate solution, and the solution was further concentrated to dryness to obtain 5888.55 g of ruthenium nitrate solid, with a conversion rate of 100% and a ruthenium content of 37.25 wt%.

[0044] The structure of the obtained ruthenium nitrosyl nitrate was characterized by infrared spectroscopy, the content of impurity metals in the product was determined by ICP, and the content of chloride ions in the ruthenium nitrosyl nitrate was determined by ion chromatography.

[0045] Among them, infrared spectrum (IR), KBr pressed tablet: 1924.09 (s, vRu-NO); metal impurity mass content and chloride ion content, the results are shown in Table 2:

[0046] Table 2 Test results of ruthenium nitrosyl nitrate obtained in Example 2

[0047] Pb (%) <0.001 Mg (%) <0.001 Rh (%) <0.001 Fe (%) 0.002 K(％) <0.001 Ir(％) <0.001 Cu (%) 0.002 Ag (%) <0.001 Au (%) <0.001 Na (%) <0.001 Pt (%) 0.002 Mn (%) <0.001 Ca (%) <0.001 Pd (%) <0.001 Co (%) <0.001 Ni (%) <0.001 Ti (%) <0.001 Si (%) 0.002 Zn (%) <0.001 Mo (%) <0.001 Cl (ppm) 1.5

[0048] Example 3

[0049] 5000 g of ruthenium acetylacetonate (ruthenium: 25.35 wt%) was weighed and placed in a 5-liter three-necked round-bottom flask equipped with a condenser. Under stirring, 3 L of 8 mol / L concentrated nitric acid was added dropwise, and ozone was introduced at the same time. The mixture was heated under reflux at 95°C for 2 h and concentrated to obtain a ruthenium nitrate solution. The obtained tail gas was absorbed by a 10 wt% sodium hydroxide solution.

[0050] NO was introduced into the above ruthenium nitrate solution, and the reaction was continued by heating at 90°C for 20 min. The solution was concentrated to obtain a ruthenium nitrate solution, and the solution was further concentrated to dryness to obtain 3409.09 g of ruthenium nitrate solid, with a conversion rate of 100% and a ruthenium content of 37.18 wt%.

[0051] The structure of the obtained ruthenium nitrosyl nitrate was characterized by infrared spectroscopy, the content of impurity metals in the product was determined by ICP, and the content of chloride ions in the ruthenium nitrosyl nitrate was determined by ion chromatography.

[0052] Among them, infrared spectrum (IR), KBr pressed tablet: 1924.09 (s, vRu-NO); metal impurity mass content and chloride ion content, the results are shown in Table 3:

[0053] Table 3 Test results of ruthenium nitrate obtained in Example 3

[0054]

[0055]

[0056] As can be seen from Tables 1 to 3, the present invention successfully prepares ruthenium nitrosyl nitrate obtained from high-purity ruthenium, and the conversion rate of metal ruthenium reaches 100%. The preparation method of ruthenium nitrosyl nitrate provided by the present invention is suitable for industrial production.

[0057] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing ruthenium nitrosyl nitrate, characterized in that: The following steps are involved: The organic ruthenium complex and an oxidant are mixed and subjected to oxidation treatment to obtain a ruthenium nitrate solution; the oxidant is a nitric acid solution and ozone; The ruthenium nitrate solution is nitrosylated in a NO atmosphere to obtain the nitrosyl ruthenium nitrate.

2. The preparation method according to claim 1, characterized in that: The organic ruthenium complex includes one or more of ruthenium oxalate, ruthenium acetate and ruthenium acetylacetonate.

3. The preparation method according to claim 1, characterized in that: The concentration of the nitric acid solution is 6-8 mol / L; the solid-liquid ratio of the organic ruthenium complex and the nitric acid solution is 5000 g:3-4 L.

4. The preparation method according to claim 1, characterized in that: The temperature of the oxidation treatment is 90-95° C. and the time is 1-2 hours.

5. The preparation method according to claim 1, characterized in that: The ozone introduction time during the oxidation treatment is 1 to 2 hours.

6. The preparation method according to claim 1, characterized in that: The temperature of the nitrosylation is 70-90° C. and the time is 10-20 min.

7. The preparation method according to claim 1, characterized in that: The tail gas obtained by the oxidation treatment is absorbed by an alkaline reagent.

8. The preparation method according to claim 7, characterized in that: The alkaline agent includes one or more of sodium hydroxide, potassium hydroxide and calcium hydroxide.

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