Method of making an inorganic platinum compound

Abstract

Provided is a method of making an inorganic platinum compound. The method includes the steps of: Step (A): providing a platinum material and a halogen-containing oxidizing agent; and Step (B): treating the platinum material with the halogen-containing oxidizing agent in a hydrochloric acid aqueous solution to obtain the inorganic platinum compound, including chloroplatinic acid or chloroplatinate salt; wherein the halogen-containing oxidizing agent excludes chlorine gas. The method of making an inorganic platinum compound is simple, safe, time-effective, cost-effective, and environment-friendly, and has the advantage of high yield.

Claims

1. A method of making an inorganic platinum compound, comprising steps of: Step (A): providing a platinum material and a halogen-containing oxidizing agent; and Step (B): treating the platinum material with the halogen-containing oxidizing agent in a hydrochloric acid aqueous solution to obtain an inorganic platinum compound; wherein the halogen-containing oxidizing agent excludes chlorine gas, and the halogen-containing oxidizing agent is selected from the group consisting of: a halogen oxoacid, a halogen oxoacid salt, a halogen oxide, and any combination thereof; wherein the halogen oxoacid comprises hypobromous acid, bromous acid, bromic acid, hypoiodous acid, iodic acid, or periodic acid; the halogen oxoacid salt comprises sodium hypobromite, sodium bromite, sodium bromate, sodium hypoiodite, sodium iodate, sodium periodate, potassium hypobromite, potassium bromite, potassium bromate, potassium hypoiodite, potassium iodate, potassium periodate, or ammonium iodate; the halogen oxide comprises dichlorine monoxide, dichlorine trioxide, dibromine monoxide, dibromine trioxide, bromine dioxide, dibromine pentoxide, diiodine monoxide, or diiodine pentoxide; and the inorganic platinum compound comprises chloroplatinic acid or chloroplatinate salt.

2. The method of making the inorganic platinum compound as claimed in claim 1, wherein in Step (B), based on the total weight of the hydrochloric acid aqueous solution, the hydrochloric acid aqueous solution contains 18 wt% to 37 wt% of hydrochloric acid.

3. The method of making the inorganic platinum compound as claimed in claim 1, wherein the halogen-containing oxidizing agent is added into the hydrochloric acid aqueous solution in a form of an aqueous solution composed of the halogen-containing oxidizing agent and water; wherein a weight ratio of the halogen-containing oxidizing agent to the water ranges from 1:1 to 1:200.

4. The method of making the inorganic platinum compound as claimed in claim 3, wherein in Step (A), relative to per gram of the platinum material, a usage of the aqueous solution ranges from 1 mL to 1000 mL.

5. The method of making the inorganic platinum compound as claimed in claim 3, wherein in Step (B), a volume ratio of the aqueous solution to the hydrochloric acid aqueous solution ranges from 1:1 to 1:50.

6. The method of making the inorganic platinum compound as claimed in claim 1, wherein in Step (B), a molar ratio of the halogen-containing oxidizing agent to the hydrochloric acid ranges from 1:1 to 1:500.

7. The method of making the inorganic platinum compound as claimed in claim 1, wherein Step (B) is performed at a temperature ranging from 10 C. to 100 C.

8. The method of making the inorganic platinum compound as claimed in claim 7, wherein the temperature in Step (B) ranges from greater than or equal to 4 C. to less than 15 C.

9. The method of making the inorganic platinum compound as claimed in claim 1, wherein Step (B) comprises: Step (b1): treating the platinum material with the halogen-containing oxidizing agent in the hydrochloric acid aqueous solution to obtain a solution comprising the inorganic platinum compound; and Step (b2): concentrating the solution comprising the inorganic platinum compound to obtain the inorganic platinum compound.

10. The method of making the inorganic platinum compound as claimed in claim 9, wherein Step (b2) is performed by rotary heating evaporation at a temperature ranging from 50 C. to 100 C. and under a pressure ranging from 0.1 mbar to 1.0 mbar.

11. The method of making the inorganic platinum compound as claimed in claim 9, wherein Step (b2) comprises: Step (b2-1): concentrating the solution comprising the inorganic platinum compound at a temperature ranging from 30 C. to 100 C. to obtain a concentrated solution; and Step (b2-2): placing the concentrated solution at a temperature ranging from 0 C. to 30 C. to obtain the inorganic platinum compound; wherein the inorganic platinum compound is in a crystalline state.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic flow diagram illustrating the method of making an inorganic platinum compound in accordance with the instant disclosure.

(2) FIG. 2 is a UV-Vis spectrum of the chloroplatinic acid obtained in Example 1 in 0.1 M HCl.sub.(aq).

(3) FIG. 3 is a UV-Vis spectrum of the sodium chloroplatinate obtained in Example 2 in 0.1 M HCl.sub.(aq).

(4) FIG. 4 is a UV-Vis spectrum of the potassium chloroplatinate obtained in Example 6 in 0.1 M HCl.sub.(aq).

(5) FIG. 5 is a TGA curve diagram of the chloroplatinic acid obtained in Example 1.

(6) FIG. 6 is a TGA curve diagram of the sodium chloroplatinate obtained in Example 2.

(7) FIG. 7 is a TGA curve diagram of the potassium chloroplatinate obtained in Example 6.

(8) FIG. 8 is a schematic flow diagram illustrating the methods of making an inorganic platinum compound in accordance with the prior art.

DETAILED DESCRIPTION OF THE DISCLOSURE

(9) Hereinafter, one skilled in the art can easily realize the advantages and effects of the instant disclosure from the following examples. Therefore, it should be understood that the descriptions proposed herein are just preferable examples for the purpose of illustrations only, not intended to limit the scope of the disclosure. Various modifications and variations could be made in order to practice or apply the instant disclosure without departing from the spirit and scope of the disclosure.

(10) With reference to FIG. 1, a method of making an inorganic platinum compound of the instant disclosure uses the halogen-containing oxidizing agent to oxidize the platinum material, wherein the inorganic platinum compound is the chloroplatinic acid, sodium chloroplatinate, potassium chloroplatinate, or ammonium chloroplatinate. The method of making an inorganic platinum compound is a single step reaction, and it can be performed in a single reactor without isolating an intermediate product.

(11) In the following Examples and Comparative Examples, Ultraviolet-visible (UV-Vis) spectra were measured on Agilent Technologies Cary60 UV-Vis spectrophotometer. TGA spectra were performed on Mettler Toledo TGA/DSC 3+ instrument. ICP-OES for analyses of the proportion of platinum in the inorganic platinum compounds were performed on Perkin Elmer optima 8X00 spectrometer. Rotary evaporation in Step (B) was performed on IKA RV10 rotary evaporator. All the reagents were reagent grade purchased from Acros Organics and were used without further purification. Platinum powder was in 99.9% purity. Water is distilled or deionized for use as a solvent.

COMPARATIVE EXAMPLE 1

Synthesis of Chloroplatinic Acid by Using Aqua Regia in HCl

(12) Platinum powders (30 mg) and aqua regia (3.5 mL of aqueous solution containing 37 wt % hydrochloric acid and 68 wt % nitric acid) were placed in a 10 mL flat-bottomed flask to form a reaction mixture. The reaction mixture was stirred at room temperature for over 6 hours until all the platinum powders were consumed to give a solution containing chloroplatinic acid. After completion of the reaction, 37 wt % hydrochloric acid was added into the solution containing chloroplatinic acid and heated at 100 C. to remove nitrogen oxides. This process of heating with adding the concentrated hydrochloric acid was repeated for several times until no brown gas of nitrogen oxides evolved. The solution was then subjected to rotary evaporation at 100 C. under reduced pressure (0.5 mbar) to concentrate the solution, followed by a stand at room temperature to obtain 79.6 mg of crystals of the chloroplatinic acid in the hexahydrate form. The yield was over 99%.

COMPARATIVE EXAMPLE 2

Two-Step Synthesis of Potassium Chloroplatinate by Using Aqua Regia, Followed by Addition of Potassium Chloride

(13) First step: Platinum powders (30 mg) and aqua regia (3.5 mL of aqueous solution containing 37 wt % hydrochloric acid and 68 wt % nitric acid) were placed in a 10 mL flat-bottomed flask to form a reaction mixture. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to give a solution containing chloroplatinic acid. After completion of the reaction, 37 wt % hydrochloric acid was repeatedly added into the solution containing chloroplatinic acid and heated at 100 C. until no brown gas of nitrogen oxides evolved. The solution was then concentrated by rotary evaporation at 100 C. under reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the chloroplatinic acid hexahydrate.

(14) Second step: The said chloroplatinic acid and 5 mL of 10 wt % aqueous potassium chloride solution were placed in a flat-bottomed flask, and then stirred at room temperature for 2 hours to complete the reaction, giving a product solution containing a yellow precipitate of potassium chloroplatinate. After filtration and drying, 90.6 mg of orange crystals of potassium chloroplatinate was obtained. The yield was over 99%.

EXAMPLE 1

Synthesis of Chloroplatinic Acid by Using Iodic Acid (HIO.SUB.3.) and Perchloric Acid (HClO.SUB.4.)

(15) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 60 mg of HIO.sub.3 and 50 L of 70 wt % HClO.sub.4, wherein a weight ratio of the gross weight of HIO.sub.3 and HClO.sub.4 to the water was 1:10.5. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:25.6. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 1 containing the chloroplatinic acid. Solution 1 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain 79.3 mg of crystals of the chloroplatinic acid hexahydrate. The yield was over 99%.

(16) Additionally, 4.3 mg of the crystal of the chloroplatinic acid hexahydrate was dissolved in 0.1 M hydrochloric acid aqueous solution. As shown in FIG. 2, its .sub.max of the UV-Vis spectrum was at 260 nm. Moreover, 6.6785 mg of the crystal of the chloroplatinic acid hexahydrate was measured by TGA, and the obtained TGA curve diagram was shown in FIG. 5. Furthermore, 8.7 mg of the crystal of the chloroplatinic acid hexahydrate was dissolved in 10.6614 g pure water, and then diluted 10 times and measured by ICP-OES. The measured result was 28.36 ppm, so the content of platinum in the chloroplatinic acid hexahydrate was about 37.67 wt %.

EXAMPLE 2

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorite (NaClO.SUB.2.) and Sodium Chlorate (NaClO.SUB.3.)

(17) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 20 mg of NaClO.sub.2 and 60 mg of NaClO.sub.3, wherein a weight ratio of the gross weight of NaClO.sub.2 and NaClO.sub.3 to the water was 1:12.5. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:38.3. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 2 containing the sodium chloroplatinate. Solution 2 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

(18) Additionally, 4.8 mg of the crystal of the sodium chloroplatinate was dissolved in 0.1 M hydrochloric acid aqueous solution. As shown in FIG. 3, its .sub.max of the UV-Vis spectrum was at 262.0 nm. Moreover, 6.0681 mg of the crystal of the sodium chloroplatinate was measured by TGA, and the obtained TGA curve diagram was shown in FIG. 6.

EXAMPLE 3

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorite (NaClO.SUB.2.) and Sodium Perchlorate (NaClO.SUB.4.)

(19) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 40 mg of NaClO.sub.2 and 60 mg of NaClO.sub.4, wherein a weight ratio of the gross weight of NaClO.sub.2 and NaClO.sub.4 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:32.2. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 3 containing the sodium chloroplatinate. Solution 3 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

EXAMPLE 4

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorite (NaClO.SUB.2.) at Low Temperature

(20) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 100 mg of NaClO.sub.2, wherein a weight ratio of NaClO.sub.2 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:26.9. The reaction mixture was stirred and cooled at 4 C. for 40 minutes until all platinum powders were consumed to obtain a Solution 4 containing the sodium chloroplatinate. Solution 4 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

EXAMPLE 5

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorite (NaClO.SUB.2.)

(21) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 100 mg of NaClO.sub.2, wherein a weight ratio of NaClO.sub.2 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:26.9. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 5 containing the sodium chloroplatinate. Solution 5 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

(22) Additionally, the crystal of the sodium chloroplatinate was measured by ICP-OES. The measured result of the content of platinum in the sodium chloroplatinate was about 42.99 wt %.

EXAMPLE 6

Synthesis of Potassium Chloroplatinate by Using Potassium Chlorate (KClO.SUB.3.)

(23) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 100 mg of KClO.sub.3, wherein a weight ratio of KClO.sub.3 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:36.5. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 6 containing the potassium chloroplatinate. Solution 6 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the potassium chloroplatinate. The yield was over 99%.

(24) Additionally, 5.1 mg of the crystal of the potassium chloroplatinate was dissolved in 0.1 M hydrochloric acid aqueous solution. As shown in FIG. 4, its .sub.max of the UV-Vis spectrum was at 262.0 nm. Moreover, 3.5253 mg of the crystal of the potassium chloroplatinate was measured by TGA, and the obtained TGA curve diagram was shown in FIG. 7. Furthermore, the crystal of the potassium chloroplatinate was measured by ICP-OES. The measured result of the content of platinum in the potassium chloroplatinate was about 40.14 wt %.

EXAMPLE 7

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorate (NaClO.SUB.3.) and Sodium Periodate (NaIO.SUB.4.)

(25) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 50 mg of NaClO.sub.3 and 50 mg of NaIO.sub.4, wherein a weight ratio of the gross weight of NaClO.sub.3 and NaIO.sub.4 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:42.7. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 7 containing the sodium chloroplatinate. Solution 7 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

EXAMPLE 8

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorate (NaClO.SUB.3.) and Perchloric Acid (HClO.SUB.4.)

(26) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 60 mg of NaClO.sub.3 and 90 L of 70 wt % HClO.sub.4, wherein a weight ratio of the gross weight of NaClO.sub.3 and HClO.sub.4 to the water was 1:6.1. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:18.7. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 8 containing the sodium chloroplatinate. Solution 8 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

EXAMPLE 9

Synthesis of Potassium Chloroplatinate by Using Ootassium Iodate (KIO.SUB.3.) and Potassium Perchlorate (KClO.SUB.4.)

(27) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 70 mg of KIO.sub.3 and 30 mg of KClO.sub.4, wherein a weight ratio of the gross weight of KIO.sub.3 and KClO.sub.4 to the water was 1:10. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:54.4. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 9 containing the potassium chloroplatinate. Solution 9 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the potassium chloroplatinate. The yield was over 99%.

EXAMPLE 10

Synthesis of Potassium Chloroplatinate by Using Potassium Iodate (KIO.SUB.3.) and Iodic Acid (HIO.SUB.3.)

(28) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 80 mg of KIO.sub.3 and 30 mg of HIO.sub.3, wherein a weight ratio of the gross weight of KIO.sub.3 and HIO.sub.3 to the water was 1:9.1. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:55.4. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 10 containing the potassium chloroplatinate. Solution 10 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the potassium chloroplatinate. The yield was over 99%.

EXAMPLE 11

Synthesis of Potassium Chloroplatinate by Using Potassium Chlorate (KClO.SUB.3.) and Potassium Perchlorate (KClO.SUB.4.)

(29) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 70 mg of KClO3 and 20 mg of KClO.sub.4, wherein a weight ratio of the gross weight of KClO.sub.3 and KClO.sub.4 to the water was 1:11.1. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:58.6. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 11 containing the potassium chloroplatinate. Solution 11 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the potassium chloroplatinate. The yield was over 99%.

EXAMPLE 12

Synthesis of Sodium Chloroplatinate by Using Perchloric Acid (HClO.SUB.4.) and Potassium Iodate (KIO.SUB.3.)

(30) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 45 L of 70 wt % HClO.sub.4 and 80 mg of KIO.sub.3, wherein a weight ratio of the gross weight of HClO.sub.4 and KIO.sub.3 to the water was 1:7.6. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:33.6. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 12 containing the sodium chloroplatinate. Solution 12 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

EXAMPLE 13

Synthesis of Potassium Chloroplatinate by Using Iodic Acid (HIO.SUB.3.), Potassium Chlorate (KClO.SUB.3.) and Potassium Perchlorate (KClO.SUB.4.)

(31) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 30 mg of HIO.sub.3, 30 mg of KClO.sub.3 and 50 mg of KClO.sub.4, wherein a weight ratio of the gross weight of HIO.sub.3, KClO.sub.3 and KClO.sub.4 to the water was 1:9.1. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:38.8. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 13 containing the potassium chloroplatinate. Solution 13 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the potassium chloroplatinate. The yield was over 99%.

EXAMPLE 14

Synthesis of Ammonium Chloroplatinate by Using Iodic Acid (HIO.SUB.3.) and Ammonium Perchlorate (NH.SUB.4.ClO.SUB.4.)

(32) Platinum powders (30 mg) and 2.5 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 10 mL flat-bottomed flask. Then, 1 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 30 mg of HIO.sub.3 and 80 mg of NH.sub.4ClO.sub.4, wherein a weight ratio of the gross weight of HIO.sub.3 and NH.sub.4ClO.sub.4 to the water was 1:9.1. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:35.2. The reaction mixture was stirred and heated at 50 C. to 60 C. for 10 minutes until all platinum powders were consumed to obtain a Solution 14 containing the ammonium chloroplatinate. Solution 14 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the ammonium chloroplatinate. The yield was over 99%.

(33) Additionally, the crystal of the ammonium chloroplatinate was measured by ICP-OES. The measured result of the content of platinum in the ammonium chloroplatinate was about 43.95 wt %.

EXAMPLE 15

Synthesis of Sodium Chloroplatinate by Using Sodium Chlorite (NaClO.SUB.2.) and Sodium Chlorate (NaClO.SUB.3.)

(34) Platinum powders (1 g) and 100 mL of concentrated hydrochloric acid aqueous solution containing 37 wt % of HCl were placed in a 500 mL flat-bottomed flask. Then, 40 mL of aqueous solution composed of the halogen-containing oxidizing agent and water was added into the flask to obtain a reaction mixture. The halogen-containing oxidizing agent contained 0.8 g of NaClO.sub.2 and 2.4 g of NaClO.sub.3, wherein a weight ratio of the gross weight of NaClO.sub.2 and NaClO.sub.3 to the water was 1:12.5. In the reaction mixture, a molar ratio of the halogen-containing oxidizing agent to HCl was 1:37.5. The reaction mixture was stirred and heated at 50 C. to 60 C. for 30 minutes until all platinum powders were consumed to obtain a Solution 15 containing the sodium chloroplatinate. Solution 15 was then concentrated by rotary evaporation at 100 C. under a reduced pressure (0.5 mbar), followed by a stand at room temperature to obtain crystals of the sodium chloroplatinate. The yield was over 99%.

DISCUSSION OF THE RESULTS

(35) Compared with Comparative Examples 1 and 2, Examples 1 to 15 of the instant disclosure could make chloroplatinic acid or chloroplatinate salts such as sodium chloroplatinate, potassium chloroplatinate and ammonium chloroplatinate without the need of taking a precaution for vigorous reaction because of the use of the specific halogen-containing oxidizing agent, such as NaClO.sub.2, NaClO.sub.3, KClO.sub.3, HClO.sub.4, NaClO.sub.4, KClO.sub.4, NH.sub.4ClO.sub.4, HIO.sub.3, KIO.sub.3, and NaIO.sub.4, to oxidize the platinum material. Specifically, in comparison to Comparative Example 1, adopting Example 1 of the instant disclosure to make the chloroplatinic acid could react completely with the same weight of the platinum powders in a shorter time. Similarly, in comparison to Comparative Example 2, adopting Examples 2 to 14 of the instant disclosure to make the chloroplatinate salts also could react completely with the same weight of the platinum powders in a shorter time, even if Example 4 was carried out at a much lower temperature (4 C.), the time required to process the reaction completely in Example 4 still was obviously shorter than the time required in Comparative Example 2. It demonstrates that the method of making an inorganic platinum compound of the instant disclosure has the advantages of time-effectiveness and high efficiency.

(36) Besides, from the result that the yield of Example 4 could still be over 99%, the method of making an inorganic platinum compound of the instant disclosure can be applied at a low temperature. Accordingly, it demonstrates that the instant disclosure is more suitable to be implemented in a place where temperature, pressure, and exhaust emissions of the process are limited strictly.

(37) Based on Examples above, the method of making an inorganic platinum compound of the instant disclosure has the advantage of simplicity, safety, time-effectiveness, cost-effectiveness, environment-friendliness, and high yield.

(38) Even though numerous characteristics and advantages of the instant disclosure have been set forth in the foregoing description, together with details of the structure and features of the disclosure, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.