Na-modified Zn@MFI molecular sieve monatomic catalyst, and preparation method and application thereof

Abstract

The application belongs to the technical field of catalysts, and particularly relates to a Na-modified Zn@MFI molecular sieve monatomic catalyst and a preparation method and application thereof. The catalyst is represented by a formula Zn-Na@MFI, wherein Zn and Na are active components, MFI is a molecular sieve carrier, Zn is dispersed in the MFI molecular sieve carrier in a monatomic form, and the loading amounts of the active components Zn and Na in the catalyst are 0.1-1wt% and 0.2-2wt% respectively. In the reaction of preparing acetaldehyde by dehydrogenation of ethanol, the catalyst realizes 100% atom utilization, and can realize high activity, high selectivity and high stability of ethanol to generate the target product acetaldehyde under mild reaction conditions. Compared with the existing metal molecular sieve catalysts for the reaction of preparing acetaldehyde by dehydrogenation of ethanol, the catalyst provided by the application has the significant advantages of good stability and high selectivity.

Description

Technical Field

[0001] The present invention belongs to the field of catalyst technology, and specifically relates to a Na-modified Zn@MFI single-atom molecular sieve catalyst, a preparation method thereof, and an application in the non-oxidative dehydrogenation of ethanol. Specifically, the coordination structure of Zn and the acidity and alkalinity of the catalyst are adjusted by using a strategy of ligand protection and Na modification, thereby achieving the conversion of ethanol into acetaldehyde with high activity, high selectivity, and high stability. Background Art

[0002] Acetaldehyde, as an important platform compound, can be catalytically converted into a series of chemical products such as acetone, butanol, crotonaldehyde, sorbitol, butadiene, and pentaerythritol, with high industrial application value [ACS Catal., 13(2023)11291-11304.]. The ethanol dehydrogenation process plays a vital role as an intermediate step in the conversion of ethanol into high-value-added products. In recent decades, the production of bioethanol has been continuously upgraded, and the use of biomass (such as cassava and cellulose) as feedstock has made the process more attractive. [Resources Chemicals and Materials, 2(2023)189-207.] In addition, ethanol dehydrogenation is a crucial step in the ethanol-liquid organic hydrogen carrier cycle system. Compared with commercially available copper-based catalysts, precious metal catalysts show higher activity in ethanol dehydrogenation reactions, but their high cost limits their widespread application [Chinese Journal of Catalysis, 49(2023)91-101.]. Therefore, there is an urgent need to develop low-cost, efficient and highly selective ethanol dehydrogenation catalysts.

[0003] Single-atom catalysts can reduce catalyst costs and maximize metal utilization efficiency. Precious metal (Au, Ag, Pt, etc.) single-atom catalysts have shown excellent catalytic performance in ethanol dehydrogenation. However, single-atom catalysts based on inexpensive metals as active centers have rarely been reported in ethanol dehydrogenation. Summary of the Invention

[0004] The present invention aims to provide a Na-modified Zn@MFI single-atom molecular sieve catalyst, its preparation method, and its application in the non-oxidative dehydrogenation of ethanol. A Zn single-atom molecular sieve catalyst is constructed by a one-step hydrothermal synthesis and crystallization method through ligand protection and base center regulation strategies, wherein Zn is dispersed in the molecular sieve in a single-atom state. The catalyst can achieve 100% Zn atom utilization, nearly 100% acetaldehyde selectivity, and 300 hours of reaction stability.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] On the one hand, the present invention provides a Na-modified Zn@MFI molecular sieve single-atom catalyst, which is represented by the formula Zn-Na@MFI, wherein Zn and Na are active components, and an MFI molecular sieve carrier is used. Zn is dispersed in the MFI molecular sieve carrier in the form of single atoms, and the loading amounts of the active components Zn and Na elements in the catalyst are 0.1-1wt% and 0.2-2wt%, respectively.

[0007] In the above technical solution, further, the loading amount of Zn element in the catalyst is 0.01-0.2 wt%; the loading amount of Na element in the catalyst is 0.02-0.5 wt%.

[0008] Another aspect of the present invention provides a method for preparing the above-mentioned catalyst, which comprises the following steps:

[0009] (1) Mixing a silicon source, a template, a ligand protective agent, a sodium source, a zinc source, and water, controlling the pH value to 9-13, and stirring for 1-5 hours to obtain a gel;

[0010] (2) subjecting the gel obtained in step (1) to a hydrothermal crystallization reaction;

[0011] (3) After the hydrothermal crystallization is completed, the catalyst is centrifuged and dried under vacuum conditions, and then reduced and calcined in a hydrogen atmosphere at a temperature of 350-750° C. for 2-6 hours to obtain the catalyst.

[0012] In the above technical solution, further, in step (1), the molar ratio of the silicon source, template, ligand protective agent, sodium source, zinc source and water is 1:2-5:0.02-0.1:0.001-0.02:0.001-0.01:20-50.

[0013] In the above technical solution, further, in step (1), the silicon source is one or both of ethyl orthosilicate and silica sol;

[0014] The sodium source is one or more of sodium nitrate, sodium hydroxide, sodium chloride, sodium benzoate, and sodium carbonate;

[0015] The zinc source is one or more of zinc nitrate, zinc chloride, zinc acetylacetonate and zinc acetate;

[0016] The template agent is one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide, and tetrabutylammonium hydroxide;

[0017] The ligand protecting agent is one or more of ethylenediamine, ethylenediaminetetraacetic acid and dopamine.

[0018] In the above technical solution, further, in step (2), the hydrothermal crystallization temperature is 100-200°C and the time is 36-120h, preferably the hydrothermal crystallization temperature is 120-180°C and the time is 60-90h.

[0019] In the above technical solution, further, in step (3), the drying temperature is 50-120°C, preferably 80-120°C;

[0020] The hydrogen flow rate is 10-100 ml / min, preferably 30-50 ml / min;

[0021] The reduction roasting temperature is 400-500° C., and the roasting time is 3-5 hours.

[0022] The present invention also provides an application of the above catalyst in the non-oxidative dehydrogenation of ethanol to acetaldehyde, wherein the reaction is carried out in a fixed bed reactor, the ethanol feed flow rate is 0.005-1 ml / min, preferably 0.01-0.2 ml / min, and the reaction mass space velocity is WHSV=0.5-10 h -1 , preferably WHSV = 1-3h -1 At least one of argon, nitrogen and helium is used as the carrier gas, the carrier gas flow rate is 40-200 mL / min, and the reaction temperature is 150-400°C, preferably 250-350°C.

[0023] The beneficial effects of the present invention are:

[0024] (1) Zn is dispersed in the molecular sieve in a single-atom state, achieving 100% atomic utilization efficiency.

[0025] (2) Using low-cost metal Zn as the active component is more economical and has a more prominent industrialization prospect than traditional precious metal (such as Au, Ag) catalysts.

[0026] (3) By introducing the base center Na, 100% selectivity for acetaldehyde was achieved.

[0027] (4) The Zn species was stabilized in the molecular sieve through a ligand protection strategy, achieving reaction stability that could last for more than 300 hours in a single run. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The XRD characterization results of the catalysts prepared in Examples 1-4 are as follows;

[0029] Figure 2 The N2 physical adsorption characterization results of the catalyst prepared in Example 1;

[0030] Figure 3The dispersion state of the active components of the catalyst prepared in Example 1 before and after the reaction;

[0031] Figure 4 The results of the catalyst stability test are shown in Example 1. DETAILED DESCRIPTION

[0032] The following examples are provided to further illustrate the present invention. The following examples may enable a person skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0033] Unless otherwise specified, the materials used in the examples of the present invention can be obtained from commercial sources or prepared according to conventional methods well known to those skilled in the art.

[0034] Example 1

[0035] The Zn-Na@MFI molecular sieve single-atom catalyst was prepared by a one-step hydrothermal synthesis crystallization method, which includes the following steps:

[0036] (1) A silicon source (ethyl orthosilicate), a template (tetrapropylammonium hydroxide), a ligand protective agent (ethylenediaminetetraacetic acid), a sodium source (sodium hydroxide), zinc acetate, and water were mixed in a molar ratio of 1:2.3:0.1:0.002:0.001:40, the pH value was adjusted to about 9, and the gel was obtained after stirring for 3 h;

[0037] (2) The obtained gel was transferred to a hydrothermal reactor and crystallized in an oven at 170°C for 72 h;

[0038] (3) After the hydrothermal crystallization is completed, the white gel is obtained by centrifugation three times, which is then vacuum dried at 120°C and then reduced and calcined at 550°C for 4 h in a hydrogen atmosphere (flow rate of 30 ml / min) to obtain a single-atom catalyst, which is recorded as Zn1-Na2@MFI.

[0039] Examples 2-4

[0040] Preparation of single-atom Zn-Na@MFI molecular sieve catalysts with different zinc loadings

[0041] The preparation process of Examples 2-4 is similar to that of Example 1, except that the content ratio of zinc to silicon is different. The molar ratio of silicon to zinc is 1:0.002, 1:0.005 and 1:0.01 respectively. The obtained catalysts are named Zn2-Na2@MFI, Zn5-Na2@MFI, Zn 10 -Na2@MFI.

[0042] The ICP results of Zn and Na in Zn-Na@MFI catalysts with different zinc loadings are shown in Table 1.

[0043] Table 1 ICP results of Zn and Na in Zn-Na@MFI catalysts with different zinc loadings

[0044] Example Catalyst Zinc loading (%) Sodium loading (%) 1 <![CDATA[Zn1-Na2@MFI]]> 0.1 0.2 2 <![CDATA[Zn2-Na2@MFI]]> 0.2 0.2 3 <![CDATA[Zn5-Na2@MFI]]> 0.5 0.2 4 <![CDATA[Zn 10 -Na2@MFI]]> 1 0.2

[0045] ICP results showed that the zinc loading in Zn-Na@MFI catalyst was in the range of 0.1%-1%.

[0046] Examples 5-7

[0047] Preparation of single-atom Zn-Na@MFI molecular sieve catalysts with different sodium contents

[0048] The preparation process of Examples 5-7 is similar to that of Example 1, except that the content ratio of sodium to silicon is different. The molar ratio of silicon to sodium is 1:0.004, 1:0.006 and 1:0.01, respectively. They are named Zn1-Na4@MFI, Zn1-Na6@MFI, Zn1-Na 10 @MFI.

[0049] ICP results of Zn and Na in Zn-Na@MFI catalysts with different sodium loadings.

[0050] Table 2 ICP results of Zn and Na in Zn-Na@MFI catalysts with different sodium loadings

[0051] Example Catalyst Zinc loading (%) Sodium loading (%) 1 Zn1-Na2@MFI 0.1 0.2 5 <![CDATA[Zn1-Na4@MFI]]> 0.1 0.4 6 <![CDATA[Zn1-Na 10 @MFI]]> 0.1 1 7 <![CDATA[Zn1-Na 20 @MFI]]> 0.1 2

[0052] ICP results showed that the sodium content in the Zn-Na@MFI catalyst was in the range of 0.2%-2%.

[0053] Examples 8-11

[0054] Preparation of single-atom Zn-Na@MFI molecular sieve catalysts at different calcination temperatures:

[0055] The preparation process of Examples 8-11 is similar to that of Example 1, except that the calcination temperatures are 350°C, 450°C, 650°C, and 750°C, respectively.

[0056] Comparative Example 1

[0057] The preparation of single-atom Zn@MFI molecular sieve catalyst includes the following steps:

[0058] (1) A silicon source (tetraethyl orthosilicate), a template (tetrapropylammonium hydroxide), a ligand protective agent (ethylenediaminetetraacetic acid), zinc acetate, and water were mixed in a molar ratio of 1:2.3:0.1:0.001:40, the pH value was adjusted to about 9, and the gel was obtained after stirring for 3 h;

[0059] (2) The obtained gel was transferred to a hydrothermal reactor and crystallized in an oven at 170°C for 72 h;

[0060] (3) After the hydrothermal crystallization is completed, the white gel is obtained by centrifugation three times, which is then vacuum dried at 120°C and then reduced and calcined at 550°C for 4 h in a hydrogen atmosphere (flow rate of 30 ml / min) to obtain the Zn@MFI single-atom catalyst.

[0061] Comparative Example 2

[0062] Nano Zn nano -The preparation of Na@MFI molecular sieve catalyst includes the following steps:

[0063] (1) A silicon source (ethyl orthosilicate), a template (tetrapropylammonium hydroxide), zinc acetate, and water were mixed in a molar ratio of 1:2.3:0.001:40, the pH value was adjusted to about 9, and the mixture was stirred for 3 h to obtain a gel;

[0064] (2) The obtained gel was transferred to a hydrothermal reactor and crystallized in an oven at 170°C for 72 h;

[0065] (3) After the hydrothermal crystallization is completed, the white gel is centrifuged three times and then dried in a vacuum at 120°C. Then, it is reduced and calcined at 550°C for 4 h in a hydrogen atmosphere (flow rate of 30 ml / min) to obtain nano Zn nano -Na@MFI catalyst.

[0066] Comparative Examples 3-5

[0067] Preparation of single-atom Zn-M@MFI molecular sieve catalysts, where M is other alkali metal centers, Li, K, and Mg.

[0068] The preparation process is similar to that of Example 1, except that the alkali metal sources are lithium hydroxide, potassium hydroxide, and magnesium hydroxide, respectively.

[0069] Comparative Example 6

[0070] The same amount of sodium was introduced into the single-atom Zn@MFI molecular sieve catalyst by impregnation method and ion exchange method. Preparation of Na / Zn@MFI catalyst by impregnation method:

[0071] The same amount of sodium as in Example 1 was introduced into the single-atom Zn@MFI molecular sieve catalyst by an impregnation method. Specifically, a certain amount of sodium nitrate was dissolved in 1 g of ultrapure water, and after sufficient stirring and dissolution, 1 g of the single-atom Zn@MFI molecular sieve catalyst in Comparative Example 1 was added and impregnated with an equal volume for 12 hours. After vacuum drying at 120°C, the catalyst was reduced and calcined at 550°C for 4 hours under a hydrogen atmosphere (flow rate of 30 ml / min) to obtain a Na / Zn@MFI catalyst.

[0072] Comparative Example 7

[0073] Preparation of Na-Zn@MFI catalyst by ion exchange method:

[0074] The same amount of sodium as in Example 1 was introduced into the single-atom Zn@MFI molecular sieve catalyst by an ion exchange method. Specifically, a certain amount of sodium nitrate was dissolved in 100 g of ultrapure water, stirred and dissolved, 1 g of the single-atom Zn@MFI molecular sieve catalyst in Comparative Example 1 was added, and the ion exchange was stirred at room temperature for 12 h. The solid sample was filtered to obtain a solid sample. After vacuum drying at 120 ° C, it was reduced and calcined at 550 ° C for 4 h in a hydrogen atmosphere (flow rate of 30 ml / min) to obtain a Na / Zn@MFI catalyst.

[0075] Application Example 1

[0076] Evaluation process of ethanol dehydrogenation catalyst to acetaldehyde: 1 g of the catalyst prepared in Comparative Examples 1-5 and Examples 1-11 was pelletized and loaded into a fixed bed reactor. The ethanol flow rate was 0.02 ml / min. The raw materials were brought into the reactor by pump feeding and nitrogen carrier gas (flow rate was 100 mL / min). The reaction space velocity was WHSV = 1 h -1 , the reaction temperature is 300℃.

[0077] Calculation method of reaction conversion and selectivity:

[0078] Ethanol conversion rate (%) = (n 反应前的乙醇 -n 反应后剩余乙醇 ) / n 反应前的乙醇 *100%

[0079] Acetaldehyde selectivity (%) = n 产物中乙醛 / (n 反应前的乙醇 -n 反应后剩余乙醇 )*100%

[0080] The performance evaluation results of the Zn-Na@MFI catalysts with different zinc loadings in Examples 1-4 are shown in Table 3.

[0081] Table 3 Performance evaluation results of Zn-Na@MFI catalysts with different zinc loadings

[0082] Example Catalyst Ethanol conversion (%) Acetaldehyde selectivity (%) 1 <![CDATA[Zn1-Na2@MFI]]> 36 100 2 <![CDATA[Zn2-Na2@MFI]]> 37 98 3 <![CDATA[Zn5-Na2@MFI]]> 38 99 4 <![CDATA[Zn 10 -Na2@MFI]]> 38 98

[0083] It can be seen from the reaction results that high selectivity for acetaldehyde can be achieved when the Zn loading is in the range of 0.01-0.1%.

[0084] The performance evaluation results of Zn-Na@MFI catalysts with different sodium loading amounts in Examples 1 and 5-7 are shown in Table 4.

[0085] Table 4 Performance evaluation results of Zn-Na@MFI catalysts with different sodium loadings

[0086] Example Catalyst Ethanol conversion (%) Acetaldehyde selectivity (%) 1 Zn1-Na2@MFI 36 100 5 <![CDATA[Zn1-Na4@MFI]]> 33 100 6 <![CDATA[Zn1-Na 10 @MFI]]> 32 100 7 <![CDATA[Zn1-Na 20 @MFI]]> 30 100

[0087] From the reaction results, it can be seen that a high selectivity of 100% for acetaldehyde can be achieved when the sodium loading is in the range of 0.2-2%.

[0088] The performance evaluation results of the Zn-Na@MFI catalysts at different calcination temperatures of Examples 1 and 8-11 are shown in Table 5.

[0089] Table 5 Catalytic performance evaluation results of single-atom Zn-Na@MFI molecular sieve catalyst at different calcination temperatures

[0090] Example Calcination temperature (°C) Ethanol conversion (%) Acetaldehyde selectivity (%) 1 550 36 100 8 350 30 97 9 450 33 99 10 650 45 98 11 750 47 96

[0091] As can be seen from the table, the catalyst provided by the present invention can stably exist and produce the target product acetaldehyde under the conditions of calcination temperature of 350-750℃, and the optimal calcination temperature for the reaction is 550℃.

[0092] In order to further highlight the superiority of the present invention, the reaction performance of the Zn-Na@MFI catalysts modified with different base centers in Example 1 and Comparative Examples 3-5 were compared. The performance evaluation results are shown in Table 6.

[0093] Table 6 Performance evaluation results of single-atom Zn-M@MFI molecular sieve catalysts modified with different base centers

[0094] Group Ethanol conversion (%) Acetaldehyde selectivity (%) Example 1 36 100 Comparative Example 3 10 70 Comparative Example 4 8 68 Comparative Example 5 5 73

[0095] The above results indicate that only the Na-modified zeolite catalyst can achieve high selectivity and high conversion of acetaldehyde.

[0096] Compared with the nanocatalyst Zn nano The reaction performance of Zn-Na@MFI with single-atom catalyst Zn-Na@MFI is shown in Table 7.

[0097] Table 7 Performance evaluation results of nanocatalysts and single-atom catalysts

[0098] Group Ethanol conversion (%) Acetaldehyde selectivity (%) Example 1 36 100 Comparative Example 2 13 79

[0099] From the reaction, it can be seen that compared with the nanocatalyst, the single-atom catalyst has significantly higher ethanol activity and acetaldehyde selectivity.

[0100] To further highlight the uniqueness of the present invention, the reaction performance of Na-modified single-atom catalysts (Na / Zn@MFI and Na-Zn@MFI) synthesized by different methods, as well as Zn@MFI single-atom catalysts without Na modification and Zn-Na@MFI single-atom catalysts were compared to further highlight the superiority of the catalyst of the present invention and prove that the effect of the present invention is unpredictable. The performance evaluation results are shown in Table 8.

[0101] Table 8 Performance evaluation results of Na-modified single-atom catalysts synthesized by different methods

[0102] Group Ethanol conversion (%) Acetaldehyde selectivity (%) Example 1 36 100 Comparative Example 1 16 72 Comparative Example 6 13 83 Comparative Example 7 15 82

[0103] As can be seen from the above table, compared with the sodium modification process in the hydrothermal synthesis process, the sodium modification process without sodium modification, the impregnation method and the ion exchange method are all unable to achieve high selectivity for acetaldehyde and high activity for ethanol. This result once again confirms the uniqueness of the present invention.

[0104] Application Example 2

[0105] 1 g of the catalyst prepared in Example 1 was pelletized and loaded into a fixed bed reactor. The ethanol flow rate was 0.02 ml / min. The raw materials were brought into the reactor by pump feeding and nitrogen carrier gas (flow rate was 100 mL / min). The reaction space velocity was WHSV=1 h -1 The catalytic performance was investigated at different reaction temperatures.

[0106] Table 9 Catalytic performance evaluation results of single-atom Zn-Na@MFI molecular sieve catalyst at different reaction temperatures

[0107] Reaction temperature (°C) Ethanol conversion (%) Acetaldehyde selectivity (%) 250 18 100 275 27 100 300 36 100 325 45 100 350 47 98 375 53 97 400 69 95

[0108] As can be seen from the table, the catalyst provided by the present invention can produce the target product acetaldehyde under the reaction conditions of 250-400°C.

[0109] Application Example 3

[0110] 1 g of the single-atom Zn-Na@MFI molecular sieve catalyst prepared in Example 1 was pelletized and loaded into a fixed bed reactor. The ethanol flow rate was 0.02 ml / min. The raw materials were brought into the reactor by pump feeding and nitrogen carrier gas (flow rate was 100 mL / min). The reaction space velocity was WHSV=1 h -1 , the reaction temperature was 300℃ for stability evaluation.

[0111] from Figure 4 It can be seen that the catalyst can operate stably for more than 300 hours, and its reaction stability is higher than that of the currently reported Zn-based catalysts, indicating that the present invention has superiority.

[0112] like Figure 1 The XRD characterization results show that the catalyst has an MFI topological structure and no characteristic peak of Zn oxide appears, indicating that Zn in the catalyst is highly dispersed.

[0113] like Figure 2 The physical adsorption characterization results show that the catalyst has a multi-level pore structure, confirming the effectiveness of the present invention.

[0114] In order to further reveal the effectiveness and innovation of base center modification, the particle size distribution of Zn nanoparticles before and after the reaction of Zn-Na@MFI catalyst was investigated by HRTEM, such as Figure 3 Electron microscopy results show that the active components of the Zn-Na@MFI catalyst are dispersed at the atomic level, demonstrating the effectiveness of the present invention in preparing single-atom metal molecular sieve catalysts. Furthermore, the Zn particles in the catalyst do not agglomerate after the reaction, a major innovation of the present invention.

[0115] In summary, the present invention uses a base-centered Na-modified Zn@MFI molecular sieve single-atom catalyst for the nonoxidative dehydrogenation of ethanol to acetaldehyde. The catalyst prepared by this strategy has the advantages of good activity, high acetaldehyde selectivity, 100% Zn atomic utilization, and good reaction cycle stability.

[0116] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the scope defined in the claims. Other variations or modifications may be made based on the above description. Obvious variations or modifications derived therefrom shall remain within the scope of protection of the present invention.

Claims

1. A Na-modified Zn@MFI molecular sieve single-atom catalyst, characterized by: The catalyst is represented by the formula Zn-Na@MFI, wherein Zn and Na are active components, pure silicon MFI molecular sieve is used as a carrier, Zn is dispersed in the pure silicon MFI molecular sieve carrier in the form of single atoms, and the loading amounts of the active components Zn and Na elements in the catalyst are 0.1-1wt% and 0.2-2wt%, respectively.

2. The catalyst according to claim 1, characterized in that: The loading amount of Zn element in the catalyst is 0.1-0.2wt%; the loading amount of Na element in the catalyst is 0.2-0.5wt%.

3. A method for preparing the catalyst according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: (1) Mix the silicon source, template, ligand protective agent, sodium source, zinc source and water, control the pH value to 9-13, and stir for 1-5 hours to obtain a gel; (2) subjecting the gel obtained in step (1) to a hydrothermal crystallization reaction; (3) After the hydrothermal crystallization is completed, centrifuge and dry under vacuum conditions, and then reduce and roast in a hydrogen atmosphere at a temperature of 350-750 o C, and the calcination time is 2-6 h to obtain the catalyst.

4. The preparation method according to claim 3, wherein: In step (1), the molar ratio of the silicon source, template, ligand protective agent, sodium source, zinc source and water is 1:2-5:0.02-0.1:0.001-0.02:0.001-0.01:20-50.

5. The preparation method according to claim 3, wherein: In step (1), the silicon source is one or both of ethyl orthosilicate and silica sol; The sodium source is one or more of sodium nitrate, sodium hydroxide, sodium chloride, sodium benzoate, and sodium carbonate; The zinc source is one or more of zinc nitrate, zinc chloride, zinc acetylacetonate and zinc acetate; The template agent is one or more of tetraethylammonium hydroxide, tetrapropylammonium hydroxide and tetrabutylammonium hydroxide; The ligand protecting agent is one or more of ethylenediamine, ethylenediaminetetraacetic acid and dopamine.

6. The preparation method according to claim 3, wherein: In step (2), the temperature of the hydrothermal crystallization is 100-200 o C, time is 36-120 h.

7. The preparation method according to claim 3, wherein: In step (3), the drying temperature is 50-120 o C, the hydrogen flow rate is 10-100 ml / min.

8. Use of the catalyst according to any one of claims 1 to 2 or the catalyst prepared by the preparation method according to any one of claims 3 to 7 in the non-oxidative dehydrogenation of ethanol to acetaldehyde, characterized in that: The reaction was carried out in a fixed bed reactor, the ethanol feed rate was 0.005-1 ml / min, and the reaction mass space velocity was WHSV = 0.5-10 h -1 At least one of argon, nitrogen, and helium is used as the carrier gas, the carrier gas flow rate is 40-200 mL / min, and the reaction temperature is 150-400 o C.

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