Supported catalyst for catalytic oxidation of glycerol to lactic acid and preparation method and application thereof

Abstract

The present application relates to the technical field of catalyst, in particular to a supported catalyst for catalytic oxidation of glycerol to lactic acid and its preparation method and application. The supported catalyst comprises active metal, auxiliary metal and carrier; wherein the active metal comprises Pt, the auxiliary metal comprises one or more of Zn, K, Co, Cu and Ni, and the carrier is a heteroatom-containing molecular sieve; the content of Lewis acid in the heteroatom-containing molecular sieve is 0.1-0.3 mmol / g. The supported catalyst can realize efficient conversion of glycerol to lactic acid under alkali-free and mild reaction conditions by constructing a bifunctional active center of metal monatomic, cluster or alloy supported on a heteroatom molecular sieve with Lewis acid metal, and significantly improves the glycerol conversion rate and lactic acid selectivity. Moreover, the preparation method of the supported catalyst is simple and efficient, which is conducive to industrialization and has good development prospect.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and in particular to a supported catalyst for the catalytic oxidation of glycerol to lactic acid, its preparation method, and its application. Background Technology

[0002] Biodiesel is a clean and renewable energy source produced through transesterification of vegetable oils with alcohols. During biodiesel production, a significant amount of glycerol is generated as a byproduct, accounting for approximately 10 wt% of biodiesel production. Over the past few decades, the rapid development of the biodiesel industry has led to a decoupling between glycerol production and actual demand. Limited by the size of the glycerol commodity market, a large surplus of glycerol has caused a sharp decline in its price. Therefore, catalyzing the conversion of glycerol into high-value-added chemicals will comprehensively improve the economics of glycerol production.

[0003] Lactic acid is an important, multifunctional platform compound with wide applications in food, pharmaceuticals, textiles, environmental protection, and agriculture. Through different reaction pathways, lactic acid can yield downstream products with higher application value. Currently, the main methods for industrial production of lactic acid include chemical synthesis and bio-fermentation. Both methods have inherent drawbacks, such as demanding reaction conditions, severe environmental pollution, and low production efficiency. Therefore, the catalytic conversion of glycerol into lactic acid, with its advantages of low cost and high atom utilization, is considered a green and sustainable production method.

[0004] In existing technologies, the production of lactic acid from glycerol requires two reaction steps. First, glycerol undergoes oxidative dehydrogenation to generate aldehydes or ketones, which can interconvert. Second, the ketone undergoes dehydration, followed by hydration and disproportionation reactions to convert it into lactic acid. However, the efficient production of lactic acid from glycerol faces numerous challenges, including the directed activation of primary and secondary hydroxyl groups, multi-step tandem catalysis, and catalyst deactivation.

[0005] In existing technologies, heterogeneous catalysts for the production of lactic acid from glycerol mainly use carbon materials, metal oxides, and molecular sieves as supports to support noble metal catalysts such as Pt, Au, and Pd. Among them, one researcher disclosed a Cu-Pt / AC catalyst, in which the formed Pt-Cu interface is beneficial to glycerol conversion. Under optimal experimental conditions (90℃, 0.1 MPa O2, reaction time 4 h), it can achieve a maximum glycerol conversion rate of 80% and a lactic acid selectivity of 69.3% (Journal of Molecular Catalysis A: Chemical, 2016, 424: 91-97); however, this method not only requires the addition of an additional base, but also produces a relatively large amount of byproducts such as glyceric acid. In addition, CN106810436A discloses a method for the catalytic oxidation of glycerol to prepare lactic acid, which involves introducing molecular oxygen into a reaction system composed of glycerol, water, catalyst, and base to carry out the oxidation reaction. Glycerol is converted to lactic acid in an aqueous solution in one step under the action of a supported metal catalyst; however, this system still requires the addition of an inorganic base.

[0006] It is evident that the currently available catalysts still have some problems in the catalytic oxidation of glycerol to produce lactic acid. For example, the reaction conditions require the addition of additional bases, which causes environmental pollution and increased costs. Furthermore, the selectivity, activity, and stability of the catalysts are still not ideal.

[0007] Therefore, providing a highly active, selective, and stable catalyst capable of catalytically oxidizing glycerol to lactic acid under alkali-free conditions is a pressing technical challenge that needs to be addressed.

[0008] In view of this, the present invention is proposed. Summary of the Invention

[0009] The purpose of this invention is to provide a supported catalyst for the catalytic oxidation of glycerol to lactic acid, its preparation method and application, so as to solve the above-mentioned technical problems and achieve efficient catalytic conversion of glycerol to lactic acid without the need to add any base.

[0010] In a first aspect, the present invention provides a supported catalyst for the catalytic oxidation of glycerol to lactic acid, comprising an active metal, a promoter metal, and a support;

[0011] The active metal includes Pt, the auxiliary metal includes one or more of Zn, K, Co, Cu and Ni, and the support is a molecular sieve containing heteroatoms; the heteroatoms are Sn.

[0012] This invention discovers that a supported catalyst composed of the above-mentioned bimetallic nanoparticles and Sn-containing molecular sieves can achieve efficient conversion of glycerol to lactic acid under alkali-free and mild reaction conditions by constructing bifunctional active centers of metal single atoms, clusters or alloys supported on heteroatom molecular sieves with Lewis acid metals, significantly improving glycerol conversion rate and lactic acid selectivity.

[0013] Meanwhile, in this invention, the addition of the auxiliary metal to the precious metal Pt not only helps to reduce the amount of precious metal Pt used, but also plays a role in dispersing and stabilizing Pt, effectively solving the problem of metal leaching in liquid phase reaction.

[0014] Preferably, the auxiliary metal is K.

[0015] When potassium (K) is introduced into a catalytic system, its poisoning effect can damage some active sites of the catalyst, causing catalyst deactivation. Therefore, it is common knowledge among those skilled in the art that potassium is not introduced when catalytically oxidizing glycerol to lactic acid. For example, patent CN106810436A uses numerous auxiliary metals, including Cu, Co, Fe, Mn, Ce, La, Ni, Mo, V, Cr, and Zn, but still does not introduce potassium (K). However, this application unexpectedly discovered that, in the aforementioned catalytic system, the strong interfacial interaction between K and Pt / Sn can significantly improve the selectivity of lactic acid while ensuring the conversion rate of glycerol.

[0016] Preferably, the Lewis acid content in the heteroatom-containing molecular sieve is 0.1–0.3 mmol / g.

[0017] Preferably, the molar ratio of Si to Sn in the heteroatom-containing molecular sieve is (50-300):1; more preferably, the molar ratio is (80-200):1.

[0018] This invention discovers that by controlling the ratio of Si to heteroatoms in a molecular sieve containing heteroatoms, the Lewis acid content of the molecular sieve can be optimized, thereby improving lactic acid selectivity.

[0019] Preferably, the molecular sieve containing heteroatoms includes one or more of MFI-type zeolite, BEA-type zeolite, MOR-type zeolite, MWW-type zeolite, and FAU-type zeolite; more preferably, the molecular sieve containing heteroatoms includes MFI-type zeolite and / or BEA-type zeolite.

[0020] Preferably, in the supported catalyst, the loading of the active metal is 0.1–10 wt%; more preferably 0.5–5 wt%; even more preferably 0.5–1.5 wt%; and most preferably 1 wt%.

[0021] Preferably, in the supported catalyst, the loading of the auxiliary metal is 0.1–10 wt%; more preferably 0.5–5 wt%; and more preferably 0.5–1.5 wt%.

[0022] Secondly, the present invention provides a method for preparing the supported catalyst for the catalytic oxidation of glycerol to lactic acid, comprising:

[0023] 1) Mix the molecular sieve containing heteroatoms, water, a soluble salt solution of an active metal, and a soluble salt solution of an auxiliary metal to obtain a mixed slurry;

[0024] 2) Evaporate all the water in the mixed slurry to obtain an intermediate product;

[0025] 3) The intermediate product is reduced in a reducing atmosphere and then cooled to room temperature in a passivating atmosphere to obtain the supported catalyst.

[0026] Preferably, the reducing atmosphere comprises 5-15 wt% H2 and 85-95 wt% N2, the reduction temperature is 300-600°C, and the isothermal reduction time is 2-8 h.

[0027] Preferably, the passivation atmosphere comprises 0.5–1.5 wt% O2 and 98.5–99.5 wt% N2, the passivation temperature is below 100°C, and the passivation time is 0.5–2 h.

[0028] Preferably, the soluble salt solution of the active metal includes one or more of chloroplatinic acid, potassium chloroplatinate, sodium chloroplatinate, and platinum acetylacetonate; more preferably, the soluble salt solution of the active metal is chloroplatinic acid.

[0029] As a preferred embodiment of the present invention, the method for preparing the supported catalyst for the catalytic oxidation of glycerol to lactic acid includes the following steps:

[0030] 1) The molecular sieve containing heteroatoms is ground and dispersed in water to obtain a suspension. Then, a soluble salt of the active metal and a soluble salt solution of the auxiliary metal are mixed, and the resulting mixed solution is added dropwise to the suspension to obtain a mixed slurry.

[0031] 2) The water in the mixed slurry is completely evaporated, and then dried and ground in sequence to obtain an intermediate product;

[0032] 3) The intermediate product is reduced in a reducing atmosphere and then cooled to room temperature in a passivating atmosphere to obtain the supported catalyst.

[0033] In practice, those skilled in the art can stir the mixture during step 1) according to the actual situation, and the stirring time is preferably 0.5 to 3 hours.

[0034] Preferably, the mixing temperature in step 1) is 30–80°C.

[0035] Preferably, in step 2), the drying temperature is 60–90°C and the drying time is 6–12 hours.

[0036] Secondly, the present invention further provides the application of the supported catalyst for the catalytic oxidation of glycerol to lactic acid in the selective catalytic oxidation of glycerol to lactic acid.

[0037] Preferably, the method for the catalytic oxidation of glycerol to lactic acid includes: mixing an aqueous glycerol solution with the supported catalyst and reacting it under an oxygen-containing atmosphere; wherein no additional alkali is added to the reaction system.

[0038] Preferably, the reaction temperature is 110–150°C; the holding time is 0.5–24 h; and the reaction pressure is 0.2–1.5 MPa.

[0039] More preferably, the reaction is heated at a rate of 2 to 5 °C / min.

[0040] As a preferred embodiment of the present invention, the method for catalytic oxidation of glycerol to lactic acid includes the following steps:

[0041] The supported catalyst and an aqueous glycerol solution were added to a high-pressure reactor and stirred to form a homogeneous mixture. Oxygen was purged several times to replace the air in the reactor, and then oxygen was added until the pressure inside the reactor was 3 MPa > P > 0 MPa. The reaction was initiated at 110–150 °C for 0.5–24 h. After the reaction was completed, the reaction solution was immediately cooled to room temperature, centrifuged, and filtered to recover the supported catalyst. The resulting filtrate was a mixture of glycerol and the product.

[0042] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0043] The supported catalyst of this invention, by constructing bifunctional active centers of metal single atoms, clusters, or alloys supported on heteroatom molecular sieves with Lewis acid metals, enables highly efficient conversion of glycerol to lactic acid under alkali-free and mild reaction conditions, significantly improving glycerol conversion rate and lactic acid selectivity. Furthermore, the preparation method of the supported catalyst is simple and efficient, conducive to industrialization, and has good development prospects. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0045] Unless otherwise specified, all raw materials used in the embodiments are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0046] Example 1

[0047] This embodiment first provides a supported catalyst, the preparation method of which includes the following steps:

[0048] (1) Mix 0.0096 g of potassium chloride solid with 2.67 mL of chloroplatinic acid hexahydrate solution (mass concentration 0.01 g / mL), then add an equal volume of deionized water to the chloroplatinic acid hexahydrate solution and sonicate for 10 min to disperse, thus obtaining a Pt-K precursor solution. Weigh 1 g of Sn-MFI molecular sieve with a silicon-to-tin ratio of 80 (using the Sn-MFI molecular sieve prepared in Example 1) and place it in a beaker. Add the Pt-K precursor solution dropwise onto the Sn-MFI molecular sieve, then add 10 mL of deionized water, stir evenly, and then place in an 80°C water bath and stir until all the solvent has evaporated.

[0049] (2) Transfer the sample to an 80℃ oven and dry for 12 hours. Take it out and grind the dried product into powder for later use.

[0050] (3) The catalyst to be reduced was reduced at 550℃ and under a 10% H2 / N2 reducing atmosphere for 2h to obtain a 1Pt-1K / Sn-MFI catalyst (the loading of the auxiliary metal K was 0.5wt%). The heating rate was controlled at 2℃ / min. The reduced catalyst was passivated by 1% O2 / N2 for 30min and then taken out for use. The flow rate of the above gases was controlled at 30mL / min.

[0051] The Sn-MFI molecular sieve contains 0.25 mmol / g of Lewis acid, and its preparation method includes the following steps:

[0052] 1) Initial gel preparation: 0.42 g of tin chloride pentahydrate (SnCl4·5H2O) and 34.00 g of tetrapropylammonium hydroxide (TPAOH, 25%) aqueous solution were added to a beaker and stirred at 500 rpm until the solid dissolved. 20.41 g of tetraethyl orthosilicate (TEOS, 98%) was added to the above solution, and the mixture was stirred at 500 rpm for 0.5 h. Then, 12.40 g of deionized water was added, and the mixture was stirred continuously for 24 h to obtain the initial gel.

[0053] 2) Hydrothermal crystallization: The initial gel obtained in step 1) was transferred to a stainless steel reactor lined with polytetrafluoroethylene and sealed. It was placed in a constant temperature drying oven at 170℃ and reacted under autogenous pressure for 48 hours.

[0054] 3) Cooling and centrifugation: Place the crystallized reaction vessel in a water bath for rapid cooling. After it has cooled to room temperature, use deionized water to repeatedly centrifuge and wash the reaction solution until the pH value of the solution drops to about 7.

[0055] 4) Drying: Place the product obtained by centrifugation in a constant temperature drying oven at 100℃ and dry for 6 hours.

[0056] 5) Calcination: The dried product is ground into powder and calcined in a muffle furnace at 550℃ for 6 hours with a heating rate of 2℃ / min to obtain Sn-MFI molecular sieve.

[0057] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, comprising the following steps:

[0058] 0.1 g of the supported catalyst was added to the lining of a high-pressure reactor equipped with a stirrer. Separately, 40 mL of a 0.3 mol / L glycerol aqueous solution was added to the lining. The reactor was purged several times with oxygen to replace the air. The reactor pressure was then increased to 0.5 MPa with oxygen. The reaction temperature was set to 120 °C and maintained for 24 h. After the reaction, the liquid was removed, cooled, centrifuged, and filtered to recover the catalyst. The resulting filtrate was a mixture of glycerol and the product. Liquid chromatography analysis showed a glycerol conversion rate of 88.8% and a lactic acid selectivity of 88.3%.

[0059] Example 2

[0060] This embodiment first provides a supported catalyst, the preparation method of which includes the following steps:

[0061] (1) Mix 0.0301 g of anhydrous copper nitrate solid with 2.67 mL of chloroplatinic acid hexahydrate solution (mass concentration 0.01 g / mL), then add an equal volume of deionized water to the chloroplatinic acid hexahydrate solution and sonicate for 10 min to disperse, thus obtaining a Pt-Cu precursor solution. Weigh 1 g of Sn-MFI molecular sieve with a silicon-to-tin ratio of 80 (using the Sn-MFI molecular sieve prepared in Example 1) and place it in a beaker. Add the Pt-Cu precursor solution dropwise onto the Sn-MFI molecular sieve, then add 10 mL of deionized water, stir evenly, and then stir in an 80°C water bath until all the solvent evaporates.

[0062] (2) Transfer the sample to an 80℃ oven and dry for 12 hours. Take it out and grind the dried product into powder.

[0063] (3) The catalyst to be reduced was reduced at 550℃ and under a 10% H2 / N2 reducing atmosphere for 2h to obtain a 1Pt-1Cu / Sn-MFI catalyst (the loading of the auxiliary metal Cu was 1wt%). The heating rate was controlled at 2℃ / min. The reduced catalyst was passivated by passing 1% O2 / N2 for 30min and then taken out for use. The flow rate of the above gases was controlled at 30mL / min.

[0064] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 99.0% and the lactic acid selectivity is 68.7%.

[0065] Example 3

[0066] This embodiment first provides a supported catalyst, the preparation method of which differs from that of Example 1 only in that 0.0096g of potassium chloride solid is replaced with 0.0460g of zinc nitrate hexahydrate, that is, the auxiliary metal is Zn.

[0067] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 98.7% and the lactic acid selectivity is 54.6%.

[0068] Example 4

[0069] This embodiment first provides a supported catalyst, the preparation method of which differs from that of Example 1 only in that 0.0096g of potassium chloride solid is replaced with 0.0499g of cobalt nitrate hexahydrate, that is, the auxiliary metal is Co.

[0070] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 98.2% and the lactic acid selectivity is 52.4%.

[0071] Example 5

[0072] This embodiment first provides a supported catalyst, the preparation method of which differs from that of Example 1 only in that 0.0096g of potassium chloride solid is replaced with 0.0506g of nickel nitrate hexahydrate, that is, the auxiliary metal is Ni.

[0073] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 99.1% and the lactic acid selectivity is 59.1%.

[0074] Example 6

[0075] This embodiment first provides a supported catalyst, the preparation method of which differs from that of Example 2 only in that: the support is a Sn-MFI molecular sieve with a silicon-tin ratio of 300 and a Lewis acid content of 0.1 mmol / g. The preparation method of this catalyst differs from that of Example 1 only in that the amount of tin chloride pentahydrate (SnCl4·5H2O) added in the initial gel preparation is 0.112 g.

[0076] This embodiment further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 99.6% and the lactic acid selectivity is 58%.

[0077] Example 7

[0078] This embodiment uses the supported catalyst 1Pt-1Cu / Sn-MFI prepared in Example 2 to catalyze the oxidation of glycerol to lactic acid. The only difference between this embodiment and Example 1 is the reaction temperature: 110°C. Liquid chromatography analysis showed that the glycerol conversion rate was 97.9% and the lactic acid selectivity was 62.7%.

[0079] Example 8

[0080] This embodiment uses the supported catalyst 1Pt-1Cu / Sn-MFI prepared in Example 2 to catalyze the oxidation of glycerol to lactic acid. The only difference between this embodiment and Example 1 is the holding time, which is 5 hours. Liquid chromatography analysis showed that the glycerol conversion rate was 85.4%, and the lactic acid selectivity was 60.5%.

[0081] Comparative Example 1

[0082] This comparative example provides a supported catalyst whose preparation method differs from that of Example 2 only in that the Sn-MFI molecular sieve with a silicon-to-tin ratio of 80 is replaced with a Ti-MFI molecular sieve with a titanium-to-tin ratio of 80, and the content of Lewis acid is 0.13 mmol / g.

[0083] This comparative example further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 98.7% and the lactic acid selectivity is 11.1%.

[0084] Comparative Example 2

[0085] This comparative example provides a supported catalyst whose preparation method differs from that of Example 2 only in that the Sn-MFI molecular sieve with a silicon-to-tin ratio of 80 is replaced with commercially available silicon carbide, and its Lewis acid content is 0.

[0086] This comparative example further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 95.0% and the lactic acid selectivity is 17.8%.

[0087] Comparative Example 3

[0088] This comparative example provides a supported catalyst whose preparation method differs from that of Example 1 only in that potassium chloride is not added.

[0089] This comparative example further provides a method for the catalytic oxidation of glycerol to lactic acid using the supported catalyst, which is the same as the method in Example 1. Liquid chromatography analysis results show that the glycerol conversion rate is 99.4% and the lactic acid selectivity is 67.6%.

[0090] This invention reveals that Lewis acidic framework Sn species are active centers with high lactic acid selectivity, while similarly Lewis acidic framework Ti species exhibit low lactic acid selectivity, highlighting the unique role of Sn species. Although SiC possesses a high specific surface area, it typically requires alkaline conditions to exhibit lactic acid selectivity. Furthermore, by introducing promoter metals, the interfacial interactions between the promoter metals and Pt and Sn species are enhanced, resulting in superior catalytic activity and selectivity.

[0091] Test case

[0092] The present invention further uses the supported catalyst 1Pt-1Cu / Sn-MFI prepared in Example 2 to verify its recovery effect in the catalytic oxidation of glycerol to lactic acid. Specifically:

[0093] 40 mL of a 0.3 mol / L glycerol aqueous solution and 0.1 g of 1Pt-1Cu / Sn-MFI catalyst were added to a high-pressure reactor equipped with a stirrer. The air in the reactor was replaced several times by purging with oxygen. Then, the reactor pressure was increased to 0.5 MPa with oxygen, and the reaction temperature was set to 120 °C and maintained for 5 h. After the reaction, the liquid was removed, cooled, centrifuged, and filtered to recover the catalyst. The filtrate was a mixture of glycerol and the product, which was analyzed by liquid chromatography. Five cycles of testing were performed, and the catalyst activity and stability remained stable. The catalyst Pt loading was 1 wt%, and the Si / Sn ratio of the Sn-MFI molecular sieve was 80. The results of glycerol-to-lactic acid conversion under the above conditions are shown in Table 1.

[0094] Table 1

[0095]

[0096] In this invention, when the auxiliary metal is Zn, K, Co or Ni other than Cu, the recovery effect of catalytic oxidation of glycerol to lactic acid is comparable to the above results, and the catalyst activity and stability remain stable.

[0097] 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 foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The application of a supported catalyst for the catalytic oxidation of glycerol to lactic acid in the selective catalytic oxidation of glycerol to lactic acid, characterized in that, The supported catalyst includes an active metal, a promoter metal, and a support; Wherein, the active metal includes Pt, the auxiliary metal is K, and the support is a molecular sieve containing heteroatoms; the heteroatoms are Sn; The molecular sieve containing heteroatoms includes one or more of the following: MFI type zeolite, BEA type zeolite, MOR type zeolite, MWW type zeolite and FAU type zeolite. The application includes: mixing an aqueous glycerol solution with the supported catalyst and carrying out an oxidation reaction under an oxygen-containing atmosphere; wherein no additional alkali is added to the reaction system.

2. The application according to claim 1, characterized in that, The content of Lewis acids in the molecular sieve containing heteroatoms is 0.1~0.3 mmol / g.

3. The application according to claim 1, characterized in that, The molar ratio of Si to Sn in the molecular sieve containing heteroatoms is (50~300):

1.

4. The application according to claim 1, characterized in that, In the supported catalyst, the loading of the active metal is 0.1~10 wt%; and / or In the supported catalyst, the loading of the promoter metal is 0.1~10 wt%.

5. The application according to claim 4, characterized in that, In the supported catalyst, the loading of the active metal is 0.5~5 wt%; and / or In the supported catalyst, the loading of the promoter metal is 0.5~5 wt%.

6. The application according to claim 5, characterized in that, In the supported catalyst, the loading of the active metal is 0.5~1.5 wt%; and / or In the supported catalyst, the loading of the promoter metal is 0.5~1.5 wt%.

7. The application according to any one of claims 1 to 6, characterized in that, The preparation method of the supported catalyst includes: 1) Mix the molecular sieve containing heteroatoms, water, a soluble salt solution of an active metal, and a soluble salt solution of an auxiliary metal to obtain a mixed slurry; 2) Evaporate all the water in the mixed slurry to obtain an intermediate product; 3) The intermediate product is reduced in a reducing atmosphere and then cooled to room temperature in a passivating atmosphere to obtain the supported catalyst.

8. The application according to claim 7, characterized in that, The reducing atmosphere consists of 5-15 wt% H2 and 85-95 wt% N2, the reduction temperature is 300-600℃, and the isothermal reduction time is 2-8h.

9. The application according to claim 8, characterized in that, The passivation atmosphere comprises 0.5~1.5wt% O2 and 98.5~99.5wt% N2, the passivation temperature is below 100℃, and the passivation time is 0.5~2h.

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