Rapid preparation method of noble metal catalyst for dehydrogenation of low-carbon alkane

Abstract

The invention discloses a rapid preparation method of a noble metal catalyst for low-carbon alkane dehydrogenation. The preparation method comprises the following steps: firstly mixing a molecular sieve, a binder and a binding agent, then adding an active metal solution and an auxiliary metal solution to form high-concentration slurry, then directly carrying out mechanical forming on the obtained high-concentration slurry to prepare a catalyst precursor, and finally drying, roasting and reducing to obtain the noble metal catalyst. According to the method, the mixed slurry is directly mechanically formed, so that the catalyst is quickly and efficiently prepared, the damage of repeated roasting to the catalyst is effectively reduced, and the obtained catalyst has the characteristics of high strength, good dispersity, excellent catalytic performance and the like, shows remarkable industrial application potential and has a wide application prospect. Therefore, an important reference basis can be provided for development of a formed high-performance industrial catalyst.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst preparation, and particularly relates to a rapid preparation method for a noble metal catalyst for dehydrogenation of light alkanes. Background Art

[0002] As an important chemical intermediate and industrial raw material, propylene plays an important role in the preparation of products such as polyolefins. With the continuous growth of market demand, its application also shows a continuous expansion trend. However, traditional production methods such as naphtha steam cracking and catalytic cracking of light diesel are gradually facing the problem of decreasing olefin yields. To address this challenge, the technology of propane catalytic dehydrogenation to propylene has emerged as a new solution. In the field of propane dehydrogenation to propylene, the mainstream catalyst is the Pt-based catalyst, which has high activity and low pollution and other advantages due to its excellent performance in catalytic dehydrogenation reactions, and has become a hot research direction at home and abroad in recent years. At present, the research on Pt-based catalysts is very in-depth, and good research results have been obtained. However, in the actual industrial dehydrogenation process, due to the long operation cycle, the catalyst particles need to have good mechanical strength to withstand physical wear and pressure changes inside the reactor, ensuring that they are not easily broken during long-term use. Therefore, the catalyst forming method is very important.

[0003] At present, common catalyst forming processes mainly include extrusion forming, rolling forming, spray forming, etc. The traditional catalyst forming process involves multiple steps. For example, Patent CN 116832858 A discloses a method for forming a titanium silicalite catalyst, including drying, primary calcination, recrystallization, secondary spraying, and secondary calcination processes to obtain a titanium silicalite catalyst product. Although large-particle catalysts can be obtained after the catalyst is formed in this invention, it requires repeated calcination, with high energy consumption and a complex process, which is not conducive to large-scale production. Patent CN112844462 A discloses a denitrification catalyst and its forming method. In the process of forming a powder catalyst, a matrix binder, a film binder, a chemical binder, and a lubricant are first added, and after mixing and kneading, it is extruded through a perforated plate of a certain shape under the action of screw rotation. The extruded material of the perforated plate is cut into columnar carrier catalysts of a certain length by slicing, and after drying and calcination, the carrier catalyst is immersed in an active component slurry containing a copper compound, and after filtration, drying, and calcination, the formed catalyst is obtained. This invention not only requires the addition of a large amount of binders, but also requires a post-treatment method to add active components, with a cumbersome process and a long cycle, which is not suitable for industrial applications. Therefore, there is an urgent need to develop a simple and rapid preparation method for forming catalysts. Summary of the Invention

[0004] The object of the present invention is to solve the problems of long preparation cycle, complex process and repeated calcination in the preparation of shaped catalysts. The present invention provides a rapid preparation method for noble metal catalysts for dehydrogenation of light alkanes. Compared with the traditional preparation of shaped catalysts, this method can not only simplify the shaping process, but also further improve the dispersion of active components. Moreover, it can avoid the repeated calcination of shaped catalysts in the conventional process, largely avoid the agglomeration of active components, and the obtained catalysts have high strength, good dispersion and propane dehydrogenation catalytic performance, showing great industrial development prospects.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A rapid preparation method for noble metal catalysts for dehydrogenation of light alkanes, which first mixes molecular sieve, binder and binder, then adds active metal solution and promoter metal solution to form a high-concentration slurry, and then directly mechanically shapes the obtained high-concentration slurry to obtain a catalyst precursor, and finally obtains the noble metal catalyst through drying, calcination and reduction.

[0006] Further, the molecular sieve is any one or several of S-1, Beta, ZSM-5, SSZ-13.

[0007] Further, the binder is any one or a mixture of several of talc powder, corn starch, wheat flour, sweet potato starch.

[0008] Further, the binder is any one or several of silica sol, aluminum sol.

[0009] Further, the active metal solution is an aqueous solution of any one or several of Pt soluble salts.

[0010] Further, the promoter metal solution contains a first promoter metal and a second promoter metal; Among them, the first promoter metal is derived from any one or several soluble salts of Sn, Zn, Cu, Ga, Ge, Ce; the second promoter metal is derived from a mixture of soluble salts of any one or several of Na, K, Ru, Cs, Mg, Ca, Sr, Ba.

[0011] Further, the content of the molecular sieve in the high-concentration slurry is 40-70 wt%, the content of the binder is 5-10 wt%, the content of the binder is 10-50 wt%, the content of the active metal is 0.1-5 wt%, the content of the first promoter metal is 0.1-5 wt%, and the content of the second promoter metal is 0.1-5 wt%.

[0012] Further, the mechanical shaping method is any one of extrusion shaping, rolling ball shaping, spray shaping.

[0013] Further, the catalyst precursor obtained by mechanical forming is spherical, strip-shaped, ingot-shaped, single-columnar or ring-shaped, and its size is 0.20 - 20 mm.

[0014] Further, the drying temperature is 100 - 200 °C, and the time is 1 - 100 h.

[0015] Further, the calcination temperature is 100 - 800 °C, and the time is 1 - 100 h.

[0016] Further, the reduction temperature is 100 - 800 °C, and the time is 1 - 100 h.

[0017] The beneficial effects of the present invention are as follows: The present invention provides a rapid preparation method for a noble metal catalyst for dehydrogenation of light alkanes. The method is to prepare a slurry from a carrier and a metal active component, then directly perform mechanical forming, and then through drying, calcination, and reduction to obtain a high-performance Pt-based catalyst. Compared with the traditional catalyst forming process, the present invention successfully simplifies the preparation process, has a shorter preparation cycle, a simpler process, and lower costs. At the same time, it effectively reduces the damage to the catalyst caused by repeated calcination, reduces energy consumption and emissions, and the obtained catalyst has high strength, good dispersion, and excellent catalytic performance. It also shows excellent stability in the high-temperature reaction of propane dehydrogenation and has broad application potential in the field of industrial catalysis. Description of the Drawings

[0018] Figure 1 It is a physical picture of the strip-shaped PtSn / ZSM-5 catalyst prepared in Example 1.

[0019] Figure 2 It is a transmission electron microscope picture (HADDF-STEM) of the PtSn / ZSM-5 catalysts prepared in Comparative Example (a) and Example 1 (b).

[0020] Figure 3 It is a performance diagram of the PtSn / ZSM-5 catalyst prepared in Example 1 during long-term propane dehydrogenation reaction. Detailed Embodiments

[0021] A rapid preparation method for a noble metal catalyst for dehydrogenation of light alkanes, which comprises the following steps: (1) Mix the molecular sieve, binder, and binder evenly for standby; (2) Prepare an active metal solution containing Pt; (3) Prepare a promoter metal solution containing a first promoter metal and a second promoter metal; (4) Mix the solutions obtained in steps (2) and (3), and slowly add the mixture drop by drop to the mixture obtained in step (1), and stir evenly to obtain a high-concentration slurry; wherein the content of the molecular sieve is 40-70 wt%, the content of the binder is 5-10 wt%, the content of the binder is 10-50 wt%, the content of the active metal is 0.1-5 wt%, the content of the first promoter metal is 0.1-5 wt%, and the content of the second promoter metal is 0.1-5 wt%. (5) Mechanically form the obtained high-concentration slurry to obtain a catalyst precursor. (6) Dry the obtained catalyst precursor at 100-200 °C for 1-100 h, calcine it at 100-800 °C for 1-100 h, and then reduce it at 100-800 °C for 1-100 h in a hydrogen atmosphere to obtain a shaped Pt-based catalyst.

[0022] Among them, in step (1), the molecular sieve is any one or more of S-1, Beta, ZSM-5, and SSZ-13. The binder is any one or a mixture of several of talc powder, corn starch, wheat flour, and sweet potato starch. The binder is any one or more of silica sol and alumina sol.

[0023] In step (2), an active metal solution containing Pt is prepared by using any one or more of Pt soluble salts.

[0024] In step (3), a promoter metal solution is prepared by using soluble salts containing the first promoter metal and the second promoter metal; the first promoter metal is any one or more of Sn, Zn, Cu, Ga, Ge, and Ce; the second promoter metal is any one or more of Na, K, Ru, Cs, Mg, Ca, Sr, and Ba.

[0025] In step (5), the mechanical forming method is any one of extrusion forming, rolling ball forming, and spray forming, and the shape of the obtained catalyst precursor is spherical, strip-shaped, ingot-shaped, single-columnar or annular, and its size is 0.20-20.0 mm.

[0026] In order to make the content of the present invention easier to understand, the technical solutions of the present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited thereto.

[0027] The drugs used in the following examples were all purchased through commercial channels unless otherwise specified. Among them, MFI zeolite (ZSM-5), BEA zeolite (Beta), pure silica zeolite (S-1), chloroplatinic acid (H2PtCl6·6H2O), stannous chloride (SnCl2·2H2O), zinc chloride (ZnCl2), cerium chloride (CeCl3), and potassium chloride (KCl) were all purchased from Aladdin Reagent Co., Ltd.

[0028] Comparative Example 1 (1) First, weigh 50.0 g of ZSM-5 zeolite, 27.1 g of silica sol, and 1.0 g of talc powder separately, mix them evenly, and add 15.0 g of deionized water to obtain a carrier slurry. (2) Add the carrier slurry to an extruder for mechanical shaping to obtain strip-shaped ZSM-5 zeolite with a length of 2 mm. (3) Place the strip-shaped ZSM-5 zeolite in an oven and dry it at 100 °C for 12 h, then place it in a muffle furnace and calcine it at 600 °C for 12 h to obtain a strip-shaped ZSM-5 zeolite carrier. (4) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir it in a 30 °C water bath for 1 h to form a homogeneous active metal solution. (5) Weigh 0.66 g of SnCl2·2H2O and 0.48 g of KCl separately, add them to 15.0 g of deionized water, stir it in a 30 °C water bath for 1 h to form a homogeneous promoter metal solution. (6) Slowly add the active metal solution and the promoter metal solution obtained in steps (4) and (5) drop by drop to the strip-shaped ZSM-5 zeolite carrier obtained in step (3) for uniform impregnation to obtain a mixture of metal and carrier. (7) Place the mixture obtained in step (6) in an oven and dry it at 100 °C for 12 h, then place it in a muffle furnace and calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere and hold it for reduction for 5 h to finally obtain a strip-shaped PtSn / ZSM-5 catalyst, where the Pt loading is 0.3 wt% and the Sn loading is 0.7 wt%.

[0029] Example 1 (1) First, weigh 50.0 g of ZSM-5 zeolite, 27.1 g of silica sol, and 1.0 g of talc powder separately, mix them evenly, and set aside. (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir it in a 30 °C water bath for 1 h to form a homogeneous active metal solution. (3) Weigh 0.66 g of SnCl2·2H2O and 0.48 g of KCl respectively, add them to 15.0 g of deionized water, and stir for 1 h in a 30 °C water bath to form a homogeneous promoter metal solution; (4) Slowly add dropwise the active metal solution and the promoter metal solution obtained in steps (2) and (3) to the mixture obtained in step (1), stir evenly to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extruder for mechanical shaping to obtain a strip-shaped PtSn / ZSM-5 catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtSn / ZSM-5 catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, hold the temperature for reduction for 5 h, and finally obtain a strip-shaped PtSn / ZSM-5 catalyst, where the Pt loading is 0.3 wt% and the Sn loading is 0.7 wt%.

[0030] Example 2 (1) First, weigh 50.0 g of Beta zeolite, 27.1 g of silica sol, and 1.0 g of talc powder respectively, mix them evenly for standby; (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir for 1 h in a 30 °C water bath to form a homogeneous active metal solution; (3) Weigh 0.66 g of SnCl2·2H2O and 0.48 g of KCl respectively, add them to 15.0 g of deionized water, and stir for 1 h in a 30 °C water bath to form a homogeneous promoter metal solution; (4) Slowly add dropwise the active metal solution and the promoter metal solution obtained in steps (2) and (3) to the mixture obtained in step (1), stir evenly to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extruder for mechanical shaping to obtain a strip-shaped PtSn / Beta catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtSn / Beta catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, hold the temperature for reduction for 5 h, and finally obtain a strip-shaped PtSn / Beta catalyst, where the Pt loading is 0.3 wt% and the Sn loading is 0.7 wt%.

[0031] Example 3 (1) First, weigh 50.0 g of S-1 molecular sieve, 27.1 g of silica sol, and 1.0 g of sesbania powder separately, mix them evenly, and set aside; (2) Weigh 0.39 g of H2PtCl6·6H2O, add it to 15.0 g of deionized water, and stir in a 30 °C water bath for 1 h to form a homogeneous active metal solution; (3) Weigh 0.66 g of SnCl2·2H2O and 0.48 g of KCl separately, add them to 15.0 g of deionized water, and stir in a 30 °C water bath for 1 h to form a homogeneous promoter metal solution; (4) Slowly add the active metal solution and the promoter metal solution obtained in steps (2) and (3) dropwise to the mixture obtained in step (1), stir evenly, and obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extruder for mechanical shaping to obtain a strip-shaped PtSn / S-1 catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtSn / S-1 catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tube furnace. Heat it up to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere and hold for 5 h of reduction. Finally, obtain a strip-shaped PtSn / S-1 catalyst, where the Pt loading is 0.3 wt% and the Sn loading is 0.7 wt%.

[0032] Example 4 (1) First, weigh 50.0 g of ZSM-5 molecular sieve, 27.1 g of silica sol, and 1.0 g of sesbania powder separately, mix them evenly, and set aside; (2) Weigh 0.39 g of H2PtCl6·6H2O, add it to 15.0 g of deionized water, and stir in a 30 °C water bath for 1 h to form a homogeneous active metal solution; (3) Weigh 0.73 g of ZnCl2 and 0.48 g of KCl separately, add them to 15.0 g of deionized water, and stir in a 30 °C water bath for 1 h to form a homogeneous promoter metal solution; (4) Slowly add the active metal solution and the promoter metal solution obtained in steps (2) and (3) dropwise to the mixture obtained in step (1), stir evenly, and obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extruder for mechanical shaping to obtain a strip-shaped PtZn / ZSM-5 catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtZn / ZSM-5 catalyst precursor in an oven and dry it at 100 °C for 12 h. Then place it in a muffle furnace and calcine it at 600 °C for 12 h. Next, place it in a tubular furnace and heat it up to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and hold the temperature for reduction for 5 h. Finally, obtain the strip-shaped PtZn / ZSM-5 catalyst, where the loading amount of Pt is 0.3 wt% and the loading amount of Zn is 0.7 wt%.

[0033] Example 5 (1) First, weigh 50.0 g of Beta zeolite, 27.1 g of silica sol, and 1.0 g of carob powder separately, mix them evenly, and set aside. (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir it in a water bath at 30 °C for 1 h to form a homogeneous active metal solution. (3) Weigh 0.73 g of ZnCl2 and 0.48 g of KCl separately, add them to 15.0 g of deionized water, stir it in a water bath at 30 °C for 1 h to form a homogeneous promoter metal solution. (4) Slowly add the active metal solution and the promoter metal solution obtained in steps (2) and (3) drop by drop to the mixture obtained in step (1), stir evenly to obtain a high-concentration slurry. (5) Put the high-concentration slurry obtained in step (4) into an extruder for mechanical shaping to obtain a strip-shaped PtZn / Beta catalyst precursor with a length of 2 mm. (6) Place the obtained strip-shaped PtZn / Beta catalyst precursor in an oven and dry it at 100 °C for 12 h. Then place it in a muffle furnace and calcine it at 600 °C for 12 h. Next, place it in a tubular furnace and heat it up to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and hold the temperature for reduction for 5 h. Finally, obtain the strip-shaped PtZn / Beta catalyst, where the loading amount of Pt is 0.3 wt% and the loading amount of Zn is 0.7 wt%.

[0034] Example 6 (1) First, weigh 50.0 g of S-1 zeolite, 27.1 g of silica sol, and 1.0 g of carob powder separately, mix them evenly, and set aside. (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir it in a water bath at 30 °C for 1 h to form a homogeneous active metal solution. (3) Weigh 0.73 g of ZnCl2 and 0.48 g of KCl separately, add them to 15.0 g of deionized water, stir it in a water bath at 30 °C for 1 h to form a homogeneous promoter metal solution. (4) Slowly add dropwise the active metal solution and the promoter metal solution obtained in steps (2) and (3) into the mixture obtained in step (1), and stir evenly to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extrusion machine for mechanical forming to obtain a strip-shaped PtZn / S-1 catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtZn / S-1 catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it up to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and keep it for reduction for 5 h to finally obtain a strip-shaped PtZn / S-1 catalyst, where the Pt loading is 0.3 wt% and the Zn loading is 0.7 wt%.

[0035] Example 7 (1) First, weigh 50.0 g of ZSM-5 molecular sieve, 27.1 g of silica sol, and 1.0 g of sesbania powder respectively, mix them evenly, and set aside; (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water, stir it in a 30 °C water bath for 1 h to form a homogeneous active metal solution; (3) Weigh 0.62 g of CeCl3 and 0.48 g of KCl respectively, add them to 15.0 g of deionized water, stir it in a 30 °C water bath for 1 h to form a homogeneous promoter metal solution; (4) Slowly add dropwise the active metal solution and the promoter metal solution obtained in steps (2) and (3) into the mixture obtained in step (1), and stir evenly to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extrusion machine for mechanical forming to obtain a strip-shaped PtCe / ZSM-5 catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtCe / ZSM-5 catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it up to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and keep it for reduction for 5 h to finally obtain a strip-shaped PtCe / ZSM-5 catalyst, where the Pt loading is 0.3 wt% and the Ce loading is 0.7 wt%.

[0036] Example 8 (1) First, weigh 50.0 g of Beta molecular sieve, 27.1 g of silica sol, and 1.0 g of sesbania powder respectively, mix them evenly, and set aside; (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water. Stir for 1 h in a water bath at 30 °C to form a homogeneous active metal solution; (3) Weigh 0.62 g of CeCl3 and 0.48 g of KCl respectively, add them to 15.0 g of deionized water, and stir for 1 h in a water bath at 30 °C to form a homogeneous promoter metal solution; (4) Slowly add the active metal solution and the promoter metal solution obtained in steps (2) and (3) drop by drop to the mixture obtained in step (1), and stir to make it uniform to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extrusion machine for mechanical forming to obtain a strip-shaped PtCe / Beta catalyst precursor with a length of 2 mm; (6) Place the obtained strip-shaped PtCe / Beta catalyst precursor in an oven, dry it at 100 °C for 12 h, then place it in a muffle furnace, calcine it at 600 °C for 12 h, and then place it in a tubular furnace. Heat it to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and keep it at this temperature for reduction for 5 h to finally obtain a strip-shaped PtCe / Beta catalyst, where the Pt loading is 0.3 wt% and the Ce loading is 0.7 wt%.

[0037] Example 9 (1) First, weigh 50.0 g of S-1 molecular sieve, 27.1 g of silica sol, and 1.0 g of talc powder respectively, mix them evenly, and set aside; (2) Weigh 0.39 g of H2PtCl6·6H2O and add it to 15.0 g of deionized water. Stir for 1 h in a water bath at 30 °C to form a homogeneous active metal solution; (3) Weigh 0.62 g of CeCl3 and 0.48 g of KCl respectively, add them to 15.0 g of deionized water, and stir for 1 h in a water bath at 30 °C to form a homogeneous promoter metal solution; (4) Slowly add the active metal solution and the promoter metal solution obtained in steps (2) and (3) drop by drop to the mixture obtained in step (1), and stir to make it uniform to obtain a high-concentration slurry; (5) Put the high-concentration slurry obtained in step (4) into an extrusion machine for mechanical forming to obtain a strip-shaped PtCe / S-1 catalyst precursor with a length of 2 mm; (6) The obtained strip-shaped PtCe / S-1 catalyst precursor was placed in an oven and dried at 100 °C for 12 h. Then it was placed in a muffle furnace and calcined at 600 °C for 12 h. Subsequently, it was placed in a tubular furnace and heated to 600 °C at a rate of 2 °C / min in a high-purity H2 atmosphere, and held for reduction for 5 h. Finally, a strip-shaped PtCe / S-1 catalyst was obtained, where the loading amount of Pt was 0.3 wt% and the loading amount of Ce was 0.7 wt%.

[0038] Figure 1 It is a physical picture of the strip-shaped PtSn / ZSM-5 catalyst prepared in Example 1.

[0039] Figure 2 It is a STEM picture of the PtSn / ZSM-5 catalysts prepared in the comparative example and Example 1. As can be seen from the figure, in the PtSn / ZSM-5 catalyst prepared in the comparative example, the active metal species agglomerated into large particles (~5 nm), while the metal particles on the surface of the PtSn / ZSM-5 catalyst prepared in Example 1 were smaller (<1 nm) and very uniformly dispersed.

[0040] The propane dehydrogenation performance of the Pt-based molecular sieve catalysts prepared in the examples and comparative examples was evaluated using a fixed-bed reactor. The specific operation was to load a certain amount of shaped Pt-based molecular sieve catalyst into the quartz tube of the reaction furnace and precisely control the temperature using a three-stage thermocouple; subsequently, hydrogen was introduced and pre-reduced at 600 °C for 5 h, and then pure propane was introduced as the reaction gas for dehydrogenation reaction, and the mass space velocity of propane was 7.0 h -1 , the reaction temperature was 600 °C, and it was calcined in an air atmosphere at 600 °C for 2 h every 12 h of reaction for regeneration, so as to investigate the catalytic activity and stability of the catalyst.

[0041] Table 1 Performance comparison of different Pt-based molecular sieve catalysts

[0042] In the present invention, the molecular sieve and the metal component were directly formulated into a slurry and mechanically rapidly formed to obtain a Pt-based molecular sieve catalyst. As can be seen from the results in Table 1, the catalysts obtained in Examples 1-9 can maintain excellent conversion and selectivity for a long time under high-temperature conditions, and the catalyst is hardly deactivated, indicating its excellent catalytic performance and cyclic regeneration performance.

[0043] Figure 3 It is a performance diagram of the PtSn / ZSM-5 catalyst prepared in Example 1 for long-time propane dehydrogenation reaction. From Figure 3 it can be seen that the prepared PtSn / ZSM-5 catalyst exhibits excellent stability, and its catalytic performance shows no obvious decreasing trend after 3000 h of reaction.

[0044] The above fully proves that the present invention prepares a Pt-based catalyst for propane dehydrogenation with excellent catalytic performance by jointly formulating a slurry of a molecular sieve and a metal component and subjecting it to one-step mechanical shaping. Its catalytic performance significantly exceeds that of the currently reported Pt-based catalysts, thus laying a foundation for the future design of high-performance shaped Pt-based catalysts.

[0045] The above are only the preferred embodiments of the present invention, and all equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A rapid preparation method of a noble metal catalyst for dehydrogenation of light alkanes, characterized in that: First, mix the molecular sieve, binder, and binder aid, then add the active metal solution and promoter metal solution to form a high-concentration slurry. Next, directly subject the obtained high-concentration slurry to mechanical shaping to obtain a catalyst precursor. Finally, through drying, calcination, and reduction, the noble metal catalyst is obtained; The promoter metal solution contains a first promoter metal and a second promoter metal.

2. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: The molecular sieve is any one or several of S-1, Beta, ZSM-5, and SSZ-13.

3. The rapid preparation method of the noble metal catalyst according to claim 1, wherein: The binder is any one or a mixture of several of sesbania powder, corn starch, wheat flour, and sweet potato starch.

4. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: The binder aid is any one or several of silica sol and alumina sol.

5. The rapid preparation method of the noble metal catalyst according to claim 1, wherein: The active metal solution is an aqueous solution of any one or several of Pt soluble salts.

6. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: The first promoter metal is derived from soluble salts of any one or several of Sn, Zn, Cu, Ga, Ge, and Ce; The second promoter metal is derived from a mixture of soluble salts of any one or several of Na, K, Ru, Cs, Mg, Ca, Sr, and Ba.

7. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: In the high-concentration slurry, the content of the molecular sieve is 40 - 70 wt%, the content of the binder is 5 - 10 wt%, the content of the binder aid is 10 - 50 wt%, the content of the active metal is 0.1 - 5 wt%, the content of the first promoter metal is 0.1 - 5 wt%, and the content of the second promoter metal is 0.1 - 5 wt%.

8. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: The method of mechanical shaping is any one of extrusion forming, rolling ball forming, and spray forming.

9. The rapid preparation method of the noble metal catalyst according to claim 1, wherein: The size of the obtained catalyst precursor is 0.20 - 20 mm.

10. The rapid preparation method of the noble metal catalyst according to claim 1, characterized in that: The drying temperature is 100 - 200 °C, and the time is 1 - 100 h; the calcination temperature is 100 - 800 °C, and the time is 1 - 100 h; the reduction temperature is 100 - 800 °C, and the time is 1 - 100 h.

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