Preparation method of Pt3Mn1 intermetallic nanoparticles loaded on SBA-15 molecular sieve as well as product and application of Pt3Mn1 intermetallic nanoparticles loaded on SBA-15 molecular sieve

Abstract

The invention belongs to the technical field of intermetallic nano materials, and particularly relates to a preparation method of Pt3Mn1 intermetallic nano particles loaded on an SBA-15 molecular sieve as well as a product and application of the Pt3Mn1 intermetallic nano particles. According to the method, chloroplatinic acid hexahydrate, manganese chloride tetrahydrate and an SBA-15 molecular sieve are mainly used as raw materials, and deionized water is added to dissolve the raw materials. The preparation method disclosed by the invention is simple, easy to operate, low in equipment requirement, low in cost and suitable for expanded production; in addition, the Pt-based bimetallic nano-catalyst material prepared by the method has excellent performance and good application prospect in the aspect of propylene preparation through propane dehydrogenation.

Description

Technical Field

[0001] The present invention belongs to the technical field of intermetallic nanomaterials, and particularly relates to a preparation method, product and application of Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve. Background Art

[0002] As an important basic organic chemical raw material, the demand for propylene has been increasing year by year with the rapid growth of the demand for downstream products such as polypropylene and acrylonitrile. Propylene is widely used in the production of plastics, rubbers, synthetic fibers and other fields, and is a key product in the petrochemical industry. The propane dehydrogenation technology can not only effectively utilize liquefied petroleum gas resources to convert them into useful olefins, but also the by-product hydrogen can be purified and applied in the new energy field, which is one of the important sources of hydrogen. In the main propane dehydrogenation industrial processes that have been successfully commercialized, CrOx-based and Pt-based catalysts occupy the main position. The catalytic activity of CrOx-based catalysts comes from Lewis acid sites, which are usually more preferable due to their low production cost. However, the inherent toxicity of CrOx species and serious side reactions have greatly hindered their application in industrial production. Regarding Pt-based catalysts, although metallic platinum is widely regarded as a promising PDH catalyst due to its environmental friendliness and excellent affinity for C-H bonds on alkanes, sintering and rapid deactivation of catalytic activity induced by coke as well as high production costs are still huge challenges.

[0003] By reasonably introducing a promoter, the active compounds in Pt-based catalysts and metal oxide-based catalysts can be effectively regulated. The promoter can greatly affect the catalytic behavior in PDH catalysts and show advantages in suppressing side reactions, inhibiting coke deposition, stabilizing active compounds, etc. For Pt-based catalysts, the addition of a promoter can adjust the geometric and electronic structures of Pt particles. This can in turn reduce the desorption energy of propylene, inhibit deep dehydrogenation, and improve the stability and selectivity of Pt-based catalysts towards propylene. In a Pt-based catalytic system, the addition of a promoter can form intermetallic compounds. Compared with disordered Pt-M alloys, structurally ordered intermetallic compound (IMC) catalysts exhibit excellent durability. This may be due to the strengthening of the interatomic bonding in the intermetallic compound alloy during the disorder-to-order transition.

[0004] Mn, as a promoter, can significantly improve the PDH performance of Pt-based catalysts. The SBA-15 molecular sieve support offers advantages such as a high specific surface area, a regular pore structure, good thermal stability, ease of modification, good reusability, and improved anti-coking performance. Therefore, this invention mainly conducts research on the mutual synergy of SBA-15 molecular sieve with Pt and Mn to form a new catalyst to improve the catalytic activity of Pt-based catalysts in propane dehydrogenation. Summary of the Invention

[0005] In view of this, one of the objectives of this invention is to provide a method for preparing Pt 3 Mn 1 intermetallic nanoparticles supported on an SBA-15 molecular sieve support; another objective is to provide a Pt 3 Mn 1 intermetallic nanoparticle catalyst supported on an SBA-15 molecular sieve support; and the third objective is to provide an application of Pt 3 Mn 1 intermetallic nanoparticles in propane dehydrogenation.

[0006] To achieve the above objectives, the specific technical solutions of this invention are as follows: 1. A method for preparing Pt 3 Mn 1 intermetallic nanoparticles supported on an SBA-15 molecular sieve, and the method comprises the following steps: (1) Dissolve chloroplatinic acid hexahydrate in deionized water and label it as precursor solution A, dissolve manganese chloride tetrahydrate in deionized water and label it as precursor solution B, and dissolve the SBA-15 molecular sieve in deionized water to obtain a support solution; (2) According to the volume ratio, take precursor solution A and precursor solution B and mix them, and further ultrasonically dissolve to obtain a precursor mixed solution, and ultrasonically dissolve the support solution as well; (3) Drop the precursor mixed solution treated in step (2) into the support solution and stir. After stirring is completed, freeze-dry the obtained solution to obtain a powder sample; (4) Subject the obtained powder to reduction calcination to obtain Pt 3 Mn 1 intermetallic nanoparticles supported on an SBA-15 molecular sieve. Preferably, the density of precursor solution A is 7-10 mg / ml, the density of precursor solution B is 7-10 mg / ml, and 7-10 ml of deionized water is added to the support SBA-15 molecular sieve.

[0007] Preferably, the volume ratio of the precursor solution A to the precursor solution B in step (2) is 1.77:1, the ultrasonic time of the precursor mixed solution is 30 minutes, and the ultrasonic time of the carrier solution is 5 minutes.

[0008] Preferably, the stirring time in step (3) is 12 hours, the freeze-drying time is 36 hours, and the freeze-drying temperature is ~ -40 °C.

[0009] Preferably, in step (4), the reduction temperature is 850 °C, and the reduction atmosphere condition is "a mixed gas of 10% H 2 and 95% Ar or a mixed gas of 5% H2 and 95% Ar by volume", the mixed gas velocity is 30 mL / min, and the reduction time is 2 - 4 hours.

[0010] 2. The Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve prepared according to the method.

[0011] 3. The application of the Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve as a catalyst for propane dehydrogenation to propylene.

[0012] The beneficial effects of the present invention are as follows: The present invention discloses a preparation method of a Pt 3 Mn 1 intermetallic nanoparticle catalyst supported on an SBA-15 molecular sieve carrier, mainly using hexachloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O), manganese chloride tetrahydrate (MnCl 2 ·4H 2 O), and SBA-15 molecular sieve as raw materials, and dissolving the raw materials by adding deionized water. The preparation method of the present invention is simple, easy to operate, has low requirements for equipment, has the advantages of low cost and low energy consumption, and is suitable for large-scale production; in addition, the Pt 3 Mn 1 intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) prepared by the present invention has the characteristics of stable structure, isolated active sites, and good catalytic performance, and has good application prospects in propane dehydrogenation to propylene.

[0013] Other advantages, objects, and features of the present invention will be set forth in part in the following description, and in part will be obvious to those skilled in the art upon examination of the following, or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where: Figure 1 Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 Intermetallic nanoparticles (Pt 3 Mn 1 / SBA-15 IMC) and the X-ray powder diffraction pattern (XRD) of the promoter-free nanoparticles (Pt / SBA-15) prepared in the comparative example; Figure 2 For the promoter-free nanoparticles (Pt / SBA-15) prepared in the comparative example (a) and Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 Intermetallic nanoparticles (Pt 3 Mn 1 / SBA-15 IMC) (b) transmission electron microscope images (HAADF-STEM) and energy-dispersive X-ray spectrometer (EDS); Figure 3 For the promoter-free nanoparticles (Pt / SBA-15) prepared in the comparative example (a) and Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 Intermetallic nanoparticles (Pt 3 Mn 1 / SBA-15 IMC) (b) aberration-corrected high-angle annular dark-field scanning transmission electron microscope images (AC-HAADF-STEM) and corresponding fast Fourier transform images (FFT); Figure 4 For the promoter-free nanoparticles (Pt / SBA-15) prepared in the comparative example (a) and Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 Intermetallic nanoparticles (Pt 3 Mn 1 / SBA-15 IMC) (b) CO infrared absorption spectra; Figure 5The conversion rate and selectivity of propane dehydrogenation to propylene of the promoter-free nanoparticle catalyst (Pt / SBA-15) (a) prepared in the comparative example and the Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 Intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) (b). Detailed implementation mode

[0015] The following specific examples illustrate the implementation modes of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following examples only illustrate the basic concept of the present invention schematically. Without conflict, the following examples and the features in the examples can be combined with each other.

[0016] Example 1 A Pt 3 Mn 1 intermetallic nanoparticle (Pt 3 Mn 1 / SBA-15 IMC), and the specific preparation method includes the following steps: (1) Add 100 mg of chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O) and 100 mg of manganese chloride tetrahydrate (MnCl 2 ·4H 2 O) into 10 ml of deionized water respectively, stir for 5 - 10 min to make them mix evenly and dissolve, and prepare a 10 mg / ml chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O) solution and a manganese chloride tetrahydrate (MnCl 2 ·4H 2 O) solution; (2) Add 100 mg of SBA-15 molecular sieve into 7 ml of deionized water, stir and ultrasonicate for 30 min, and stir for 10 min to make them mix evenly and dissolve to form a carrier solution; (3) Drop 0.804 ml of chloroplatinic acid tetrahydrate solution and 0.453 ml of manganese chloride solution into the carrier solution, and stir for 12 h. Then freeze-dry the above mixed solution for 24 h to obtain a uniform powder; (4) The obtained powder sample is reduced and calcined in an atmosphere of 850 °C and 5% H2 / Ar for 4 h to obtain Pt supported on the SBA-15 molecular sieve support. 3 Mn 1 Intermetallic nanoparticles (labeled: Pt 3 Mn 1 / SBA-15 IMC).

[0017] Example 2 A kind of Pt 3 Mn 1 intermetallic nanoparticles supported on the SBA-15 molecular sieve support (Pt 3 Mn 1 / SBA-15 IMC), and the specific preparation method includes the following steps: (1) 100 mg of chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O) and 100 mg of manganese chloride tetrahydrate (MnCl 2 ·4H 2 O) are respectively added to 10 ml of deionized water, stirred for 5 - 10 min to make them mix evenly and dissolve, and a 10 mg / ml chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O) solution and a manganese chloride tetrahydrate (MnCl 2 ·4H 2 O) solution are prepared; (2) 100 mg of SBA-15 molecular sieve is added to 10 ml of deionized water, stirred and ultrasonicated for 2 h, and stirred for 1 h to make it mix evenly and dissolve to form a carrier solution; (3) 0.804 ml of chloroplatinic acid tetrahydrate solution and 0.453 ml of manganese chloride solution are added dropwise to the carrier solution, and stirred for 16 h. Then the above mixed solution is freeze-dried for 36 h to obtain a uniform powder; (4) The obtained powder sample is reduced and calcined in an atmosphere of 950 °C and 5% H2 / Ar for 2 h, then cooled to 600 °C at a rate of 1 °C / min, and naturally cooled to room temperature to obtain Pt 3 Mn 1 intermetallic nanoparticles supported on the SBA-15 molecular sieve support (labeled: Pt 3 Mn 1 / SBA-15 IMC ② )

[0018] Comparative Example A kind of Pt nanoparticles supported on SBA-15 molecular sieve carrier (Pt / SBA-15), and the specific preparation method includes the following steps: In step (1) of the above-mentioned Example 1, a 10 mg / ml manganese chloride tetrahydrate solution is not prepared, and manganese chloride tetrahydrate is not added in step (3), and other conditions remain unchanged, to obtain Pt nanoparticles supported on SBA-15 molecular sieve carrier (Pt / SBA-15).

[0019] Performance test Using the Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve carrier (Pt 3 Mn 1 / SBA-15 IMC) prepared in Example 1 as the sample, and the Pt nanoparticles supported on SBA-15 molecular sieve carrier (Pt / SBA-15) prepared in the comparative example as the control, to test the relevant performances, specifically as follows: Taking the Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve carrier (Pt 3 Mn 1 / SBA-15 IMC) prepared in Example 1 and the Pt nanoparticles supported on SBA-15 molecular sieve carrier (Pt / SBA-15) prepared in the comparative example for X-ray powder diffraction test (XRD), and the results are as Figure 1 shown. It can be seen from Figure 1 that the diffraction characteristic peaks of the Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve carrier (Pt 3 Mn 1 / SBA-15 IMC) prepared in Example 1 are consistent with the characteristic peaks of the standard comparison card (PDF#04-003-3878), indicating the successful synthesis of Pt 3 Mn 1 IMC; on the other hand, the XRD pattern shows that the intermetallic order degree in Pt 3 Mn 1 / SBA-15 IMC reaches 69%.

[0020] Taking the Pt nanoparticles supported on SBA-15 molecular sieve carrier (Pt / SBA-15) prepared in the comparative example and the Pt 3 Mn 1 intermetallic nanoparticles supported on SBA-15 molecular sieve carrier (Pt 3 Mn 1 / SBA-15 IMC) was analyzed by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and energy-dispersive X-ray spectroscopy (EDS), and the results are shown in a and b respectively. From Figure 2 as shown in Figure 2 it can be seen that, compared with Figure 2 the Pt nanoparticle catalyst (Pt / SBA-15) supported on the SBA-15 molecular sieve carrier prepared in the comparative example in a, Figure 2 the Pt prepared in Example 1 in b 3 Mn 1 / SBA-15 IMC has significantly reduced particle size, and good aggregation of Pt and Mn elements, which is beneficial to propane adsorption, propylene desorption, and inhibition of coke formation.

[0021] The Pt nanoparticles supported on the SBA-15 molecular sieve carrier (Pt / SBA-15) prepared in the comparative example and the Pt supported on the SBA-15 molecular sieve carrier prepared in Example 1 3 Mn 1 intermetallic nanoparticles (Pt 3 Mn 1 / SBA-15 IMC) were tested by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC-HAADF-STEM) to obtain the corresponding atomic image information, and the results are shown in a and b respectively. Figure 3 as shown in Figure 3 The AC-HAADF-STEM data of Pt / SBA-15 in a shows that Pt nanoparticles are formed, and the fast Fourier transform image (FFT) shows the formation of the (111) plane of Pt nanoparticles; while in b, it shows that Pt 3 Mn 1 / SBA-15 IMC's AC-HAADF-STEM data shows that Pt 3 Mn 1 IMC nanoparticles are formed, and the fast Fourier transform image (FFT) shows the formation of the (100) and (110) planes of Pt 3 Mn 1 IMC.

[0022] The Pt 3 Mn 1 intermetallic nanoparticles (Pt 3 Mn 1The high-resolution transmission electron microscope images (HRTEM) of the Pt nanoparticles supported on the SBA-15 molecular sieve support (Pt / SBA-15) prepared in the comparative example and the Pt-Mn / SBA-15 IMC prepared in Example 1 after the propane dehydrogenation reaction to produce propylene are as follows Figure 4 shown in a and b of Figure 4 As can be seen, the size of the Pt nanoparticles supported on the SBA-15 molecular sieve support prepared in the comparative example (Pt / SBA-15) becomes significantly larger after the propane dehydrogenation reaction, which may be an important reason for the relatively low propane dehydrogenation performance; for the Pt-Mn / SBA-15 IMC catalyst prepared in Example 1, the change in the size of the nanoparticles after the propane dehydrogenation reaction is weak, which plays a crucial role in improving the propane dehydrogenation to produce propylene. 3 Mn 1 / SBA-15 IMC catalyst has a weaker change in nanoparticle size after the propane dehydrogenation reaction, which plays a crucial role in improving the propane dehydrogenation to produce propylene.

[0023] To better verify the properties of the Pt-Mn / SBA-15 IMC catalyst prepared in the present invention, the propane dehydrogenation performance of the Pt-Mn1 / SBA-15 IMC catalyst prepared in Example 1 was tested as follows: First, a mixture of 100 mg of the catalyst and 1.5 g of quartz sand was filled in the middle section of a quartz reaction tube with an inner diameter of 6 mm. And, appropriate amounts of quartz wool were filled above and below the catalyst and quartz sand mixture to prevent the mixture from being carried away by the gas. The catalyst was screened with an 80-mesh sieve; then a thermocouple was inserted in the middle of the catalyst bed to achieve temperature control. Then the temperature was raised from room temperature to 600 °C by program control, and the catalytic heating rate was 5 °C / min. When the temperature reached 600 °C, the catalyst was further reduced in a 5% H-95% Ar (30 mL / min) atmosphere for 90 min. After reduction, a mixture of C-H-H-N (volume ratio of C-H-H-N is 1:1:3) with a total flow rate of 25 mL / min was fed into the reactor at 600 °C; finally, the components flowing out after the reaction were automatically sampled by a gas chromatograph every 10 min to collect the propane dehydrogenation catalytic performance test. 3 Mn 1 / SBA-15 IMC catalyst, the test method is as follows: First, a mixture of 100 mg of the catalyst and 1.5 g of quartz sand was filled in the middle section of a quartz reaction tube with an inner diameter of 6 mm. And, appropriate amounts of quartz wool were filled above and below the catalyst and quartz sand mixture to prevent the mixture from being carried away by the gas. The catalyst was screened with an 80-mesh sieve; then a thermocouple was inserted in the middle of the catalyst bed to achieve temperature control. Then the temperature was raised from room temperature to 600 °C by program control, and the catalytic heating rate was 5 °C / min. When the temperature reached 600 °C, the catalyst was further reduced in a 5% H-95% Ar (30 mL / min) atmosphere for 90 min. After reduction, a mixture of C-H-H-N (volume ratio of C-H-H-N is 1:1:3) with a total flow rate of 25 mL / min was fed into the reactor at 600 °C; finally, the components flowing out after the reaction were automatically sampled by a gas chromatograph every 10 min to collect the propane dehydrogenation catalytic performance test. 3 Mn1 / SBA-15 IMC catalyst for propane dehydrogenation performance, the test method is as follows: First, in the middle section of a quartz reaction tube with an inner diameter of 6 mm, fill a mixture of 100 mg of the catalyst and 1.5 g of quartz sand, and, fill appropriate amounts of quartz wool above and below the catalyst and quartz sand mixture to prevent the mixture from being carried away by the gas. The catalyst was screened with an 80-mesh sieve; then a thermocouple was inserted in the middle of the catalyst bed to achieve temperature control. Then, the temperature was raised from room temperature to 600 °C by program control, and the catalytic heating rate was 5 °C / min. When the temperature reached 600 °C, the catalyst was further reduced in a 5% H-95% Ar (30 mL / min) atmosphere for 90 min. After reduction, a mixture of C-H-H-N (volume ratio of C-H-H-N is 1:1:3) with a total flow rate of 25 mL / min was fed into the reactor at 600 °C; finally, the components flowing out after the reaction were automatically sampled by a gas chromatograph every 10 min to collect the propane dehydrogenation catalytic performance test. 2 / 95% Ar(30 mL / min) atmosphere for 90 min. After reduction, the mixture of C-H-H-N (volume ratio of C-H-H-N is 1:1:3) with a total flow rate of 25 mL / min was fed into the reactor at 600 °C; finally, the components flowing out after the reaction were automatically sampled by a gas chromatograph every 10 min to collect the propane dehydrogenation catalytic performance test. 3 H 8 、H 2 and N 2 (C-H-H-N (volume ratio of C-H-H-N is 1:1:3) 3 H 8 / H 2 / N 2 volume ratio is 1:1:3) was fed into the 600 °C reactor; finally, the components flowing out after the reaction were automatically sampled by a gas chromatograph every 10 min for the propane dehydrogenation catalytic performance test.

[0024] At the same time, the Pt nanoparticles supported on the SBA-15 molecular sieve support prepared in the comparative example (Pt / SBA-15) were also subjected to the same operation. The test results are as Figure 5 shown, where a is the conversion rate and b is the selectivity. FromFigure 5 It can be clearly seen that the propane dehydrogenation catalytic performance of introducing the Mn promoter to form intermetallic compounds has been significantly improved.

[0025] Similarly, for the Pt 3 Mn 1 intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) prepared in Example 2, the above performance tests were carried out, and the results were similar to those of the Pt 3 Mn 1 intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) prepared in Example 1.

[0026] In summary, the present invention discloses a preparation method of a Pt 3 Mn 1 intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) supported on an SBA-15 molecular sieve carrier. The main raw materials are chloroplatinic acid hexahydrate (H 2 PtCl 6 ·6H 2 O), manganese chloride tetrahydrate (MnCl 2 ·4H 2 O), and SBA-15 molecular sieve. The raw materials are dissolved by adding deionized water. The preparation method of the present invention is simple, easy to operate, has low requirements for equipment, and has the advantages of low cost and low energy consumption, and is suitable for large-scale production; in addition, the Pt 3 Mn 1 intermetallic nanoparticle catalyst (Pt 3 Mn 1 / SBA-15 IMC) supported on the SBA-15 molecular sieve carrier prepared by the present invention has the characteristics of stable structure, isolated active sites, and good catalytic performance, and has good application prospects in the dehydrogenation of propane to propylene.

[0027] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A method for preparing Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve, characterized in that: The method comprises the following steps: (1) dissolving chloroplatinic acid hexahydrate in deionized water (labeled as precursor solution A), dissolving manganese chloride tetrahydrate in deionized water (labeled as precursor solution B), and dissolving SBA-15 molecular sieve in deionized water to obtain a carrier solution; (2) Precursor solution A and precursor solution B are mixed according to volume ratio and further ultrasonically dissolved to obtain a precursor mixed solution, and the carrier solution is also ultrasonically dissolved; (3) adding the precursor mixed solution treated in step (2) dropwise to the carrier solution and stirring, and after the stirring is completed, freeze-drying the obtained solution to obtain a powder sample; (4) The obtained powder is subjected to reduction calcination to obtain Pt3Mn1 intermetallic nanoparticles supported on the SBA-15 molecular sieve.

2. The method for preparing Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve according to claim 1, characterized in that: The density of the precursor solution A is 7-10 mg / ml, the density of the precursor solution B is 7-10 mg / ml, and 7-10 ml of deionized water is added to the carrier SBA-15 molecular sieve.

3. The method for preparing Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve according to claim 1, characterized in that: In step (2), the volume ratio of the precursor solution A to the precursor solution B is 1.77:1, the ultrasonic time of the precursor mixed solution is 30 minutes, and the ultrasonic time of the carrier solution is 5 minutes.

4. The method for preparing Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve according to claim 1, characterized in that: The stirring time in step (3) is 12 hours, the freeze-drying time is 36 hours, and the freeze-drying temperature is -40°C.

5. The method for preparing Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve according to claim 1, characterized in that: In step (4), the reduction temperature is 850° C., the reducing atmosphere is “a mixture of 10% H2 and 95% Ar or a mixture of 5% H2 and 95% Ar by volume”, the mixed gas flow rate is 30 mL / min, and the reduction time is 2 to 4 hours.

6. Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve prepared according to the method of any one of claims 1 to 5.

7. Use of the Pt3Mn1 intermetallic nanoparticles supported on SBA-15 molecular sieve as claimed in claim 6 as a catalyst for dehydrogenation of propane to propylene.

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