Di (hydroxyl) tetraammineplatinum (II) as well as preparation method and application thereof

Abstract

The invention discloses bis (hydroxyl) tetraammineplatinum (II) as well as a preparation method and application thereof, and belongs to the technical field of platinum compound preparation. The preparation method comprises the following steps: (1) dissolving tetraammineplatinum bicarbonate into water to prepare a tetraammineplatinum bicarbonate solution, dissolving alkaline earth metal hydroxide into water to prepare an alkaline earth hydroxide solution, slowly adding the alkaline earth metal hydroxide solution into the tetraammineplatinum bicarbonate solution, reacting for a period of time, adding ammoniated ammonium carboxylate into the liquid, and reacting for a period of time to obtain a mixed solution; carrying out solid-liquid separation treatment on the liquid to obtain precipitate and filtrate; and (2) carrying out rotary evaporation drying on the filtrate to obtain the bis (hydroxyl) tetraammineplatinum (II). In the preparation process, easily soluble harmful ions are not involved, and the bis (hydroxyl) tetraammineplatinum (II) precursor which is relatively high in purity and relatively stable can be prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of platinum compound preparation, and particularly relates to di(hydroxy)tetraamineplatinum (II) and a preparation method and application thereof. Background Art

[0002] Platinum catalyst precursors refer to platinum compounds that incorporate active ingredients into supported catalysts. Common examples include hexachloroplatinic acid (H2PtCl6·xH2O), ammonium chloroplatinate ((NH4)2[PtCl6]), platinum chloride (PtCl2), and tetrachloroplatinum salts (such as K2PtCl4). However, since chlorine-containing compounds almost always have high solubility, these platinum catalyst precursors are prone to generating residual chloride ions during use, which can contaminate the reaction system and leave residual chlorine in the catalyst, inhibiting active sites and significantly reducing the catalyst's catalytic activity and service life. Furthermore, in certain reaction environments (e.g., high temperatures), chloride ions can generate toxic chlorine gas, which can be harmful to humans and corrode equipment. Furthermore, chlorine-containing platinum catalyst precursors can affect the catalyst's crystal structure and particle size distribution, thereby reducing reaction selectivity. Therefore, in applications such as automotive exhaust purification catalysts and VOC treatment catalysts, the chlorine content must be strictly limited, while in areas such as green chemistry or food and medicine, the presence of chlorine must be eliminated.

[0003] Similarly, nitrates are also prone to forming residues. Platinum catalyst precursors produce nitrogen oxides during use, causing damage to the environment, and residues containing compounds such as Na will affect product purity.

[0004] Therefore, it is necessary to provide a di(hydroxy)tetraamineplatinum(II) and its preparation method and application, which avoids the introduction of easily soluble harmful ions such as chloride ions, sodium ions, and nitrate ions during the preparation process, thereby obtaining di(hydroxy)tetraamineplatinum(II) with high purity and environmental friendliness, which helps to improve the catalytic activity and service life of the subsequently prepared platinum catalyst, and at the same time makes the platinum catalyst also environmentally friendly. Summary of the Invention

[0005] In order to overcome the problems in the background technology, the present invention uses tetraammineplatinum bicarbonate ([Pt(NH3)4](HCO3)2) and alkaline earth metal hydroxide to prepare a new platinum catalyst precursor di(hydroxy)tetraammineplatinum (II) ([Pt(NH3)4)](OH)2), thereby avoiding the introduction of easily soluble harmful ions such as chloride ions, sodium ions, and nitrate ions during the entire preparation process, avoiding the residual harmful ions that would negatively affect the use of the platinum catalyst precursor, and at the same time, the platinum catalyst precursor of the present invention itself does not contain the aforementioned harmful ions.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In one aspect, the present invention provides a method for preparing di(hydroxy)tetraamineplatinum(II), comprising the following steps:

[0008] (1) Tetraammine platinum bicarbonate ([Pt(NH3)4](HCO3)2) is dissolved in water to prepare a tetraammine platinum bicarbonate solution, and alkaline earth metal hydroxide is dissolved in water to prepare an alkaline earth hydroxide solution. The alkaline earth metal hydroxide solution is slowly added to the tetraammine platinum bicarbonate solution, and the reaction is heated to a constant temperature for a period of time, and the reaction temperature is continued to be maintained. Ammonium carboxylate is added to the reaction liquid and the reaction is continued to be constant temperature for a certain period of time. After the reaction is completed, the liquid is subjected to solid-liquid separation treatment to obtain a precipitate and a filtrate. The concentrations of the [Pt(NH3)4](HCO3)2 solution and the alkaline earth metal hydroxide solution do not affect the reaction. It is only necessary to dissolve [Pt(NH3)4](HCO3)2 in a sufficient amount of water to completely dissolve [Pt(NH3)4](HCO3)2, and to dissolve the alkaline earth metal hydroxide in a sufficient amount of water to completely dissolve the alkaline earth metal hydroxide.

[0009] (2) The filtrate is subjected to rotary evaporation and drying to obtain di(hydroxy)tetraammineplatinum (II).

[0010] Preferably, in step (1), the molar ratio of tetraammineplatinum bicarbonate to alkaline earth metal hydroxide is tetraammineplatinum bicarbonate:alkaline earth metal hydroxide=1:(1-1.5).

[0011] Preferably, in step (1), the reaction temperature of tetraammineplatinum bicarbonate and alkaline earth metal hydroxide is 60-70° C., and the reaction time is 0.5-1 h.

[0012] Preferably, in step (1), the molar ratio of the amount of ammoniated ammonium carboxylate added to tetraammine platinum bicarbonate is ammoniated ammonium carboxylate:tetraammine platinum bicarbonate=(0.1-0.5):1.

[0013] Preferably, in the step (1), after adding the ammonium carboxylate, the mixture is reacted at a constant temperature for 30 minutes to complete the reaction.

[0014] Preferably, in step (1), before adding the ammoniated ammonium carboxylate to the reaction liquid, an ammonium oxalate solution is first added to the reaction liquid until no more precipitate is generated, and then the ammoniated ammonium carboxylate is added to the reaction liquid.

[0015] On the other hand, the present invention provides di(hydroxy)tetraamineplatinum (II) prepared by the above-mentioned preparation method, wherein the di(hydroxy)tetraamineplatinum (II) includes di(hydroxy)tetraamineplatinum (II) A and di(hydroxy)tetraamineplatinum (II) B.

[0016] The present invention also proposes the application of the two aforementioned di(hydroxy)tetraamineplatinum(II). The di(hydroxy)tetraamineplatinum(II) A is used as a platinum catalyst precursor for preparing an automobile exhaust treatment catalyst, and the di(hydroxy)tetraamineplatinum(II) B is used as a platinum catalyst precursor for preparing a Pt / C catalyst.

[0017] Beneficial effects of the present invention:

[0018] 1. The present invention avoids the introduction of soluble harmful ions throughout the entire preparation process, thereby eliminating the negative impact of soluble harmful ions on the platinum catalyst precursor, so that the prepared novel di(hydroxy)tetraamineplatinum (II) catalyst precursor has excellent performance.

[0019] 2. The di(hydroxy)tetraamineplatinum (II) prepared by the present invention is used as a platinum catalyst precursor. In the subsequent process of preparing the catalyst, it usually needs to be dissolved in water. The better the stability of the precursor, the higher the solubility can be maintained during the storage process, so that the precursor still has a high solubility in the subsequent catalyst preparation process, which is convenient for its use in catalyst preparation. The present invention can effectively improve the stability of the target product by adding ammonium carboxylate, so that its properties are stabilized during the storage process, thereby improving the performance of the precursor product in the subsequent catalyst preparation process.

[0020] 3. The present invention removes residual alkaline earth metal ions by adding ammonium oxalate and utilizing its characteristic of being easily decomposed by heat, with almost no negative impact on the purity of the target product. Thus, by controlling the content of alkaline earth metal ions and oxalate, di(hydroxy)tetraamineplatinum(II)A or di(hydroxy)tetraamineplatinum(II)A is prepared to obtain a platinum catalyst precursor that can be applied to different sub-sectors, making the platinum catalyst precursor more precisely applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a high performance liquid chromatogram of [Pt(NH3)4)](OH)2 prepared in Example 1 of the present invention.

[0022] Figure 2 This is a picture of the stratification of the solution after the reaction with the addition of ammonium oxalate and the actual picture of the filtrate after filtration in Example 1 of the present invention.

[0023] Figure 3This is the surface oxalate ion chromatogram of [Pt(NH3)4)](OH)2 prepared in Example 1 of the present invention.

[0024] Figure 4 This is a thermogravimetric test diagram of [Pt(NH3)4)](OH)2 prepared in Example 5 of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0026] Chemical reagents not otherwise specified in the examples and comparative examples of the present invention were all commercially available analytically pure.

[0027] Example 1

[0028] This example prepares di(hydroxy)tetraammineplatinum(II) B by the following method:

[0029] (1) Weigh 1.93 g (5 mmol) of [Pt(NH3)4](HCO3)2 and 1.56 g (5.2 mmol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution under stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, add 0.20 g of ammonium acetate to the reaction system while maintaining a constant temperature. Stir and react for 30 min. Let it stand until the liquid is separated into two layers: the upper layer is a clear solution and the lower layer is a white solid precipitate. Continue to add ammonium oxalate dropwise to the upper clear solution under constant temperature until no white precipitate is formed. Use a sand core funnel to separate the precipitate and filtrate.

[0030] (2) Rinse the precipitate three times with deionized water, mix the washed liquid with the filtrate (a small amount of filtrate may adhere to the precipitate, and washing the precipitate can wash off the filtrate attached to the precipitate. The washed liquid contains a small amount of filtrate. Combine the washed liquid with the filtrate obtained by separation with the sand core funnel and then perform rotary evaporation to collect the precursor product attached to the precipitate), perform vacuum rotary evaporation on the filtrate to obtain a white product, add ethanol for reverse analysis (since the product will adhere to the rotary evaporation bottle after rotary evaporation, ethanol is needed to wash the product out of the rotary evaporation bottle), filter and collect the solid matter, wash it three times with ethanol, and dry it at 50°C for 4h to obtain a white solid product, i.e. [Pt(NH3)4](OH)2.

[0031] This example produced 1.41 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 95.21%. This indicates that the present invention for preparing [Pt(NH₃)₄)](OH)₂ has a high target product yield and high raw material utilization, which helps reduce production costs.

[0032] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0033] Example 2

[0034] In this example, di(hydroxy)tetraammineplatinum(II)B was prepared by the following method

[0035] (1) Weigh 3.85 g (10 mmol) of [Pt(NH3)4](HCO3)2 and 3.12 g (10.4 mmol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution under stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, add 0.38 g of ammonium acetate to the reaction system while maintaining a constant temperature. Stir and react for 30 min. Let it stand until the liquid is separated into two layers: the upper layer is a clear solution and the lower layer is a white solid precipitate. Continue to add ammonium oxalate dropwise to the upper clear solution under constant temperature until no white precipitate is formed. Use a sand core funnel to separate the precipitate and filtrate.

[0036] (2) The precipitate was washed three times with deionized water, the washed liquid was mixed with the filtrate, and the filtrate was subjected to vacuum rotary evaporation to obtain a white product, which was reversed by adding ethanol. The solid matter was collected by filtration, washed three times with ethanol, and dried at 50°C for 4 hours to obtain a white solid product, namely [Pt(NH3)4](OH)2.

[0037] This example produced 2.81 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 94.85%. This indicates that the present invention for preparing [Pt(NH₃)₄)](OH)₂ has a high target product yield and high raw material utilization, which helps reduce production costs.

[0038] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0039] Example 3

[0040] In this example, di(hydroxy)tetraammineplatinum(II)B was prepared by the following method

[0041] (1) Weigh 38.53 g (0.1 mol) of [Pt(NH3)4](HCO3)2 and 44.92 g (0.15 mol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add the Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution while stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, add 3.08 g of ammonium acetate to the reaction system while maintaining a constant temperature. Stir and react for 30 min. Let it stand until the liquid is separated into two layers: the upper layer is a clear solution and the lower layer is a white solid precipitate. Continue to add ammonium oxalate dropwise to the upper clear solution while maintaining a constant temperature until no white precipitate forms. Use a sand core funnel to separate the precipitate and the filtrate.

[0042] (2) The precipitate was washed three times with deionized water, the washed liquid was mixed with the filtrate, and the filtrate was subjected to vacuum rotary evaporation to obtain a white product, which was reversed by adding ethanol. The solid matter was collected by filtration, washed three times with ethanol, and dried at 50°C for 4 hours to obtain a white solid product, namely [Pt(NH3)4](OH)2.

[0043] This example produced 37.09 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 96.25%. This indicates that the present invention for preparing [Pt(NH₃)₄)](OH)₂ has a high target product yield and high raw material utilization, which helps reduce production costs.

[0044] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0045] Example 4

[0046] In this example, di(hydroxy)tetraammineplatinum(II)B was prepared by the following method

[0047] (1) Weigh 192.77 g (0.5 mol) of [Pt(NH3)4](HCO3)2 and 224.60 g (0.75 mol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add the Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution while stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, add 7.70 g of ammonium acetate to the reaction system while maintaining a constant temperature. Stir and react for 30 min. Let it stand until the liquid is separated into two layers: the upper layer is a clear solution and the lower layer is a white solid precipitate. Continue to add ammonium oxalate dropwise to the upper clear solution while maintaining a constant temperature until no white precipitate forms. Use a sand core funnel to separate the precipitate and filtrate.

[0048] (2) The precipitate was washed three times with deionized water, the washed liquid was mixed with the filtrate, and the filtrate was subjected to vacuum rotary evaporation to obtain a white product, which was reversed by adding ethanol. The solid matter was collected by filtration, washed three times with ethanol, and dried at 50°C for 4 hours to obtain a white solid product, namely [Pt(NH3)4](OH)2.

[0049] This example produced 142.7 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 96%. This indicates that the preparation of [Pt(NH₃)₄)](OH)₂ by the present invention has a high target product yield and high raw material utilization, which helps reduce production costs.

[0050] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0051] Example 5

[0052] This example prepares di(hydroxy)tetraamineplatinum(II) A by the following method:

[0053] (1) Weigh 3.85 g (10.0 mmol) of [Pt(NH3)4](HCO3)2 and 2.02 g (13.0 mol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add the Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution while stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, maintain the constant temperature and add 0.77 g (10.0 mmol) of ammonium acetate to the reaction system. Stir and react for 0.5 h. Let it stand until the liquid is separated into layers. The upper layer is a clear solution and the lower layer is a white solid precipitate. Use a sand core funnel to separate the precipitate and the filtrate.

[0054] (2) The precipitate was washed three times with deionized water, the washed liquid was mixed with the filtrate, and the filtrate was subjected to vacuum rotary evaporation to obtain a white product, which was reversed by adding ethanol. The solid matter was collected by filtration, washed three times with ethanol, and dried at 50°C for 4 hours to obtain a white solid product, namely [Pt(NH3)4](OH)2.

[0055] This example produced 2.82 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 94.86%. This indicates that the preparation of [Pt(NH₃)₄)](OH)₂ by the present invention has a high target product yield and high raw material utilization, which helps reduce production costs.

[0056] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0057] The product prepared in this example was tested by ion chromatography (IC), and the Ba content in the product was obtained. 2+ The content is 0.26mg / L.

[0058] After the product prepared in this example was allowed to stand for 7 days, 0.5 g was added to 10 mL of distilled water to obtain a colorless, clear solution. This demonstrates that the precursor product exhibited good stability during storage and maintained high solubility after storage, facilitating its use in subsequent catalyst preparation.

[0059] Example 6

[0060] This example prepares di(hydroxy)tetraammineplatinum(II) B by the following method:

[0061] (1) Weigh 11.55 g (30 mmol) of [Pt(NH3)4](HCO3)2 and 10.50 g (33.3 mol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add the Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution under stirring. A white precipitate is observed to form. Heat the reaction system to 70°C and continue stirring for 0.5 h. Then, add 1.15 g (14.93 mmol) of ammonium acetate to the reaction system while maintaining a constant temperature. Stir and react for 30 min. Let it stand until the liquid is separated into two layers: the upper layer is a clear solution and the lower layer is a white solid precipitate. Continue to add ammonium oxalate dropwise to the upper clear solution under constant temperature until no white precipitate is formed. Use a sand core funnel to separate the precipitate and filtrate.

[0062] (2) Rinse the precipitate three times with deionized water, and adjust the total weight of the filtrate to 117 g to obtain a colorless, clear solution of [Pt(NH3)4](OH)2 with a Pt content of 5%. The product exists in the form of an aqueous solution.

[0063] Example 7

[0064] This example prepares di(hydroxy)tetraamineplatinum(II) A by the following method:

[0065] (1) Weigh 7.70 g (20.0 mmol) of [Pt(NH3)4](HCO3)2 and 9.46 g (30.0 mol) of Ba(OH)2·8H2O, respectively, and dissolve them in deionized water. Slowly add the Ba(OH)2·8H2O solution to the [Pt(NH3)4](HCO3)2 solution while stirring. A white precipitate is observed to form. Heat the reaction system to 60°C and continue stirring for 0.5 h. Then, maintain the constant temperature and add 0.77 g (10.0 mmol) of ammonium acetate to the reaction system. Stir and react for 0.5 h. Let it stand until the liquid is separated into layers. The upper layer is a clear solution and the lower layer is a white solid precipitate. Use a sand core funnel to separate the precipitate and the filtrate.

[0066] (2) The precipitate was washed three times with deionized water, the washed liquid was mixed with the filtrate, and the filtrate was subjected to vacuum rotary evaporation to obtain a white product, which was reversed by adding ethanol. The solid matter was collected by filtration, washed three times with ethanol, and dried at 50°C for 4 hours to obtain a white solid product, namely [Pt(NH3)4](OH)2.

[0067] This example produced 5.66 g of [Pt(NH₃)₄](OH)₂, with a target product yield of 95.31%. This indicates that the preparation of [Pt(NH₃)₄)](OH)₂ by the present invention has a high target product yield and high raw material utilization, which helps reduce production costs.

[0068] Comparative Example 1

[0069] In this comparative example, [Pt(NH3)4](OH)2 was prepared by the same method as in Example 1, except that no ammoniated ammonium carboxylate was added during the preparation process of this comparative example.

[0070] This comparative example finally obtained 1.43 g of white solid product [Pt(NH3)4](OH)2, with a yield of 96.62%.

[0071] After 7 days of storage, 0.5 g of the product was added to 10 mL of distilled water, and a small amount of insoluble white solid was observed. This demonstrates that the storage stability of the product was reduced in this comparative example without the addition of ammonium carboxylate. The solubility decreased after storage, making it unsuitable for subsequent use of the precursor product in catalyst preparation.

[0072] Comparative Example 2

[0073] In this comparative example, [Pt(NH3)4](OH)2 was prepared in the same manner as in Example 7, except that no ammoniated ammonium carboxylate and ammonium oxalate were added during the preparation process of this comparative example.

[0074] This comparative example obtained 5.62 g of white solid product [Pt(NH3)4](OH)2, with a yield of 94.58%.

[0075] After 7 days of storage, 0.5 g of the product was added to 10 mL of distilled water, and a small amount of insoluble white solid was observed. This demonstrates that the storage stability of the product was reduced in this comparative example without the addition of ammonium carboxylate. The solubility decreased after storage, making it unsuitable for subsequent use of the precursor product in catalyst preparation.

[0076] Effect Example 1

[0077] Test sample: di(hydroxy)tetraammineplatinum(II) B prepared in Examples 1-4.

[0078] Using the di(hydroxy)tetraammineplatinum(II)B prepared in Example 1-4 as a precursor, a platinum catalyst was prepared according to the following method:

[0079] The activated carbon is subjected to acidification and oxidation treatment to obtain pretreated activated carbon. 3 g of the pretreated activated carbon is then added to 20 ml of water and stirred to obtain a slurry. The test sample is added and stirring is continued for 4 hours. Finally, 20 ml of a reducing agent (hydrazine hydrate) is added and stirred for reduction for 4 hours. The Pt-loaded activated carbon is removed, washed to neutrality, and vacuum-dried at 80°C to obtain a Pt / C catalyst. The Pt loading is 4% of the total catalyst mass. The precursor prepared by the present invention can be used to prepare a Pt / C catalyst.

[0080] Effect Example 2

[0081] Test sample: di(hydroxy)tetraamineplatinum(II)A prepared in Example 5 or Example 7.

[0082] Using di(hydroxy)tetraamineplatinum(II)B prepared in Example 5 or Example 7 as a precursor, a platinum catalyst was prepared according to the following method:

[0083] The catalyst was prepared by an impregnation method with the test sample as the active component and the molecular sieve as the carrier. The Pt loading amount was 1.93% of the total mass of the catalyst.

[0084] The prepared catalyst was used for automobile exhaust treatment, namely for the catalytic conversion of CH4 in natural gas (CNG) engines. A small sample simulated gas distribution test (SGB) was used to investigate the catalyst's CH4 oxidation conversion efficiency. The simulated gas distribution conditions were CH4 1000mL / m 3 +8% O2+5% H2O+86.9% N2 (volume fraction), the test space velocity is 80000h -1 The temperature when the CH4 conversion rate is 50% is about 370°C, which shows that the product prepared in Example 5 or Example 7 can be used as a precursor to prepare automobile exhaust treatment catalyst.

[0085] pass Figure 1 It can be seen that the precursor product prepared by the present invention has a higher purity.

[0086] pass Figure 2 It can be seen that the reaction process of the present invention is confirmed to occur.

[0087] pass Figure 3 It can be seen that the product contains oxalate.

[0088] pass Figure 4 It can be seen that the product has good thermal stability.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for preparing di(hydroxy)tetraammineplatinum(II), characterized in that: The preparation method comprises the following steps: (1) dissolving tetraammine platinum bicarbonate in water to prepare a tetraammine platinum bicarbonate solution, dissolving alkaline earth metal hydroxide in water to prepare an alkaline earth hydroxide solution, slowly adding the alkaline earth metal hydroxide solution to the tetraammine platinum bicarbonate solution, heating and isothermal reaction for a period of time, continuing to maintain the reaction temperature, adding ammonium carboxylate to the reaction liquid, and then isothermal reaction for a certain period of time, the reaction is completed, and the liquid is subjected to solid-liquid separation treatment to obtain a precipitate and a filtrate; (2) The filtrate is subjected to rotary evaporation and drying to obtain di(hydroxy)tetraammineplatinum (II).

2. The preparation method according to claim 1, wherein: In the step (1), the molar ratio of tetraammineplatinum bicarbonate to alkaline earth metal hydroxide is tetraammineplatinum bicarbonate:alkaline earth metal hydroxide=1:(1-1.5).

3. The preparation method according to claim 1, wherein: In the step (1), the reaction temperature of tetraammineplatinum bicarbonate and alkaline earth metal hydroxide is 60-70° C., and the reaction time is 0.5-1 h.

4. The preparation method according to claim 1, wherein: In the step (1), the molar ratio of the amount of ammoniated ammonium carboxylate added to tetraammine platinum bicarbonate is ammoniated ammonium carboxylate:tetraammine platinum bicarbonate=(0.1-0.5):

1.

5. The preparation method according to claim 1, wherein: In the step (1), after adding the ammonium carboxylate, the reaction is continued at a constant temperature for 30 minutes to complete the reaction.

6. The preparation method according to any one of claims 1 to 5, characterized in that: In the step (1), before adding the ammoniated ammonium carboxylate to the reaction liquid, an ammonium oxalate solution is first added to the reaction liquid until no more precipitate is generated, and then the ammoniated ammonium carboxylate is added to the reaction liquid.

7. Di(hydroxy)tetraamineplatinum (II) prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The di(hydroxy)tetraamineplatinum(II) is di(hydroxy)tetraamineplatinum(II)A.

8. The di(hydroxy)tetraamineplatinum (II) prepared by the preparation method according to claim 6, characterized in that: The di(hydroxy)tetraamine platinum (II) is di(hydroxy)tetraamine platinum (II) B.

9. The use of di(hydroxy)tetraamineplatinum (II) according to claim 7, characterized in that: The di(hydroxy)tetraamineplatinum(II)A is used as a platinum catalyst precursor for preparing an automobile exhaust treatment catalyst.

10. The use of di(hydroxy)tetraamineplatinum (II) according to claim 8, characterized in that: The di(hydroxy)tetraamineplatinum(II)B is used as a platinum catalyst precursor to prepare a Pt / C catalyst.

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