A nitrogen-carbon modified catalyst for the production of butadiene from ethanol, its preparation method and application

Abstract

This invention discloses a nitrogen-carbon modified ethanol-to-butadiene catalyst, its preparation method, and its application, belonging to the field of ethanol-to-butadiene technology. The catalyst of this invention is loaded with two active components, M1 and M2. M1 is one or more of Cu, Zn, Ag, Cr, and Co, and M2 is one or more of oxidized Zr, Hf, Ta, Y, Sn, and Nb. The total loading of the active metals M1 and M2 in the catalyst is ≥0.1 wt%. The loadings of nitrogen and carbon in the catalyst are both ≥0.1 wt%. The support is a silicon-based support. The catalyst is obtained by co-impregnating a solution containing soluble salts of active components M1 and M2 and a soluble nitrogen-carbon source in the silicon-based support, drying, and calcining in an inert gas atmosphere. The catalyst of this invention exhibits extremely high activity and butadiene selectivity in the one-step ethanol-to-butadiene reaction, with an ethanol conversion rate of over 90% and a butadiene selectivity of over 70%. It can operate stably for over 200 hours and has excellent application prospects.

Description

Technical Field

[0001] This invention belongs to the field of ethanol-to-butadiene technology, specifically relating to a nitrogen-carbon modified ethanol-to-butadiene catalyst, its preparation method, and its application in the one-step catalytic conversion of ethanol to butadiene. Background Technology

[0002] 1,3-Butadiene (butadiene for short) is an important basic organic raw material in petrochemicals, widely used in the preparation of polymer products such as synthetic rubber and synthetic resins. With the acceleration of global industrialization, the demand for butadiene has continued to grow, reaching tens of millions of tons annually, and is increasing year by year at a stable growth rate (Han Qiao, Tan Zhihe, Gao Yujian, et al. Research progress on catalysts for the preparation of 1,3-butadiene from ethanol [J]. Industrial Catalysis, 2024, 32(03): 1-8.). Currently, the main source of butadiene is the separation of by-products from the process of ethylene production by naphtha steam cracking, which makes butadiene production highly dependent on the scale of ethylene production and the supply of cracking feedstock. However, with the increase in shale gas production, the composition of cracking feedstock has changed significantly, which has had a significant impact on butadiene production. In view of this, exploring a sustainable and environmentally friendly butadiene production route has become an urgent problem to be solved.

[0003] The technology for producing butadiene from ethanol has a long history, dating back more than a century, and was once the dominant process for industrial butadiene production (Bin Samsudin I, Zhang H, Jaenicke S, Chuah GK. Recent Advances in Catalysts for the Conversion of Ethanol to Butadiene. Chemistry AnAsian Journal. 2020; 15(24): 4199-214.). Ethanol, as a biomass resource that is abundant, inexpensive, and environmentally friendly, is more in line with my country's carbon peaking and carbon neutrality goals compared to non-renewable fossil resources. Therefore, using ethanol as a raw material to produce butadiene not only has broad market application prospects but also has important scientific research value.

[0004] There are two main processes for producing butadiene from ethanol: the one-step process and the two-step process. The one-step process uses only ethanol as a feedstock to produce butadiene in a single step; while the two-step process uses both ethanol and acetaldehyde as feedstocks to produce butadiene. The one-step process has lower selectivity due to the synergistic effects of multiple active sites, including dehydrogenation, aldol condensation, and dehydration. Furthermore, the catalyst stability is significantly lower than that of the two-step process due to carbon deposition and the aggregation of dehydrogenation sites. Currently, the highest reported stability for the one-step process is around 80 hours, indicating considerable room for improvement. Summary of the Invention

[0005] The purpose of this invention is to provide a nitrogen-carbon modified ethanol-to-butadiene catalyst, its preparation method, and its application in the one-step catalytic conversion of ethanol to butadiene. The nitrogen-carbon modified catalyst prepared by this invention can achieve high activity, high selectivity, and high stability in the production of the target product butadiene from ethanol. Moreover, the catalyst preparation method has significant advantages such as low cost, simplicity, ease of implementation, and strong universality.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a nitrogen-carbon modified catalyst for the production of butadiene from ethanol, wherein the catalyst is represented by the formula M1-M2 / NC@support, wherein M1 and M2 are both active components, M1 is one or more of Cu, Zn, Ag, Cr, and Co, and M2 is one or more of Zr, Hf, Ta, Y, Sn, and Nb in oxidized state, and the total loading of active metals M1 and M2 in the catalyst is ≥0.1wt%; NC represents the nitrogen and carbon modification of the catalyst, the loading of nitrogen in the catalyst is ≥0.1wt%, and the loading of carbon in the catalyst is ≥0.1wt%; support is a silicon-based support.

[0008] Based on the above technical solution, further, the loading of M1 element in the catalyst is 0.1-25 wt%; the loading of M2 element in the catalyst is 1-50 wt%; the loading of nitrogen element in the catalyst is 1-15 wt%; and the loading of carbon element in the catalyst is 0.5-25 wt%.

[0009] Preferably, the loading of M1 element in the catalyst is 0.2-20 wt%; the loading of M2 element in the catalyst is 1.5-30 wt%; the loading of nitrogen element in the catalyst is 1.5-10 wt%; and the loading of carbon element in the catalyst is 1.5-20 wt%.

[0010] More preferably, the loading of M1 element in the catalyst is 0.4-10 wt%; the loading of M1 element in the catalyst is 4-20 wt%; the loading of nitrogen element in the catalyst is 2-8 wt%; and the loading of carbon element in the catalyst is 2-15 wt%.

[0011] Based on the above technical solution, the silicon-based carrier is further described as a silicon-based molecular sieve or porous silica. The silicon-based molecular sieve includes one or more of SBA-15, SBA-16, silicate-1, deAl-beta, MCM-41, MWW, and NMSS. The porous silica includes one or more of silica, silica sol, and mesoporous silica. The specific surface area of ​​the porous silica is greater than 20 m² / g.

[0012] Based on the above technical solution, the preparation method of the NMSS silicon-based molecular sieve is as follows: 100 mL of 90N hexadecyltrimethylammonium chloride aqueous solution with a mass fraction of 15-35 wt% is added to 120-180 mL of ultrapure water, followed by the addition of 0.5-0.9 g of triethanolamine. The mixture is stirred until homogeneous, and the resulting solution is stirred at 50-70°C for 0.5-5 hours. 50-100 mL of tetraethyl orthosilicate / cyclohexane solution with a volume percentage of 10-30% is slowly added. After continuous stirring at 60-80°C for 10-20 hours, the upper oil phase of cyclohexane is removed, and the mixture is aged at 90-95°C for 2-5 hours. The resulting solid is centrifuged, washed, and dried, and then calcined at 600-700°C for 2-8 hours.

[0013] Secondly, the present invention provides a method for preparing the above-mentioned catalyst, comprising the following steps: a solution containing soluble salts of active components M1 and M2 and a soluble nitrogen and carbon source is co-impregnated in a silicon-based support, dried, and then calcined in an inert gas at a temperature of 350-750°C for 1-24 hours to obtain the catalyst.

[0014] Based on the above technical solution, further, the soluble salts of the active components M1 and M2 are one or more of the corresponding nitrates, chlorides, oxynitrates, oxychlorides, and organic alkoxides.

[0015] Based on the above technical solution, the nitrogen and carbon source is one or more of urea, cyanamide, dicyandiamide, melamine, thiourea, isobutyramide, diformylhydrazine, and dopamine.

[0016] Based on the above technical solution, the inert gas is one or more of nitrogen, argon, and helium.

[0017] Based on the above technical solution, the drying temperature is further 60-200℃, the calcination temperature is 500-600℃, and the calcination time is 2-6 hours.

[0018] Thirdly, the present invention provides the application of the above-mentioned catalyst in the one-step production of butadiene from ethanol.

[0019] Based on the above technical solution, the reaction is further carried out in an atmospheric pressure fixed-bed reactor with a reaction space velocity (WHSV) range of 0.12-10 h⁻¹. -1 Using inert gas as the carrier gas, the carrier gas space velocity (GSHV) is 500-10000 h⁻¹. -1 The reaction temperature is 200-500℃.

[0020] Based on the above technical solution, furthermore, the reaction temperature is 300-400℃, and the reaction space velocity range is WHSV = 0.25-6h. -1 The inert gas is one or more of nitrogen, argon, and helium, and the carrier gas space velocity is 1000-5000 h⁻¹. -1 .

[0021] Based on the above technical solution, further, in the reaction process, the ethanol conversion rate is 40-100%, and the 1,3-butadiene product selectivity is 50-80%.

[0022] The present invention has the following beneficial effects:

[0023] (1) The present invention uses nitrogen and carbon modification to prepare a one-step catalyst for the production of butadiene from ethanol. The modified catalyst can achieve high activity, high selectivity, high stability of ethanol and generate the target product butadiene. Different commercial supports can also be used for the catalyst support, and the catalyst reaction performance for different active components is also improved.

[0024] (2) The reaction stability of the catalyst for one-step ethanol-to-butadiene synthesis prepared in this invention is significantly improved, which is superior to all known catalysts reported to date.

[0025] (3) The catalyst of the present invention exhibits extremely high activity and butadiene selectivity in the one-step ethanol-to-butadiene reaction. The ethanol conversion rate can reach more than 90%, and the butadiene selectivity is as high as 70%. It can operate stably for more than 200 hours and has a very good application prospect. Attached Figure Description

[0026] Figure 1 The stability test results are for 0.5% Zn-4% Zr / NMSS.

[0027] Figure 2 The stability test results are for 0.5% Zn-4% Zr / NC@NMSS. Detailed Implementation

[0028] The following detailed description is provided through specific embodiments.

[0029] Example 1

[0030] The preparation of Zn-Zr / NC@NMSS catalysts with different loadings includes the following steps:

[0031] (1) Synthesis method of carrier NMSS:

[0032] 96 mL of a 25 wt% aqueous solution of hexadecyltrimethylammonium chloride (CTAC) was added to 144 mL of ultrapure water, followed by 0.72 g of triethanolamine (TEA). The mixture was stirred until homogeneous, and the resulting solution was transferred to a 500 mL round-bottom flask and stirred slowly in an oil bath at 60 °C for 1 hour. 80 mL of a tetraethyl orthosilicate / cyclohexane (20 vol / vol%) solution was slowly added to the above solution, and the mixture was stirred continuously in an oil bath at 75 °C for 12 hours. The cyclohexane solution in the upper oil phase was completely removed, and the mixture was aged at 90 °C for 3 hours. The solid product was centrifuged and washed several times, and then dried overnight in an oven at 80 °C. The white solid obtained by calcining the solid at 650 °C for 4 hours in a muffle furnace was NMSS.

[0033] (2) Preparation of Zn-Zr / NC@NMSS catalysts with different loadings:

[0034] Zinc nitrate and zirconium oxynitrate of different concentrations were dissolved in water, and 1g of urea was added. The mixture was stirred thoroughly to dissolve the zinc nitrate and zirconium oxynitrate, and then impregnated with the above-mentioned NMSS support in equal volume for 12h. The loading of Zn was selected as 0.5%, 1%, 2%, 5%, 10%, and 20%, and the loading of Zr was selected as 2%, 4%, 8%, 12%, and 16% (all mass fractions). After drying at 80℃ for 8h, the above samples were calcined in a tube furnace at 550℃ and 100mL / min nitrogen atmosphere for 4h to obtain catalysts with different loadings.

[0035] Comparative Example 1

[0036] The preparation of Zn-Zr / NMSS catalyst includes the following steps:

[0037] The NMSS support was synthesized using the same method as in Example 1. Then, an aqueous solution of zinc nitrate and zirconium oxynitrate was impregnated with the support in equal volumes for 12 h. The loading of Zn was selected as 0.5%, and the loading of Zr was selected as 2%, 4%, 8%, 12%, and 16% (all by mass fractions). After drying at 80 °C for 8 h, the above samples were calcined in a muffle furnace at 550 °C for 4 h to obtain Zn-Zr / C(@NMSS catalysts) with different loadings.

[0038] Comparative Example 2

[0039] The preparation of Zn-Zr / C@NMSS catalyst includes the following steps:

[0040] (1) Synthesis method of carrier C@NMSS:

[0041] The preparation process is similar to the NMSS synthesis method in Example 1, except that the last step is not calcined in a muffle furnace, but in a tube furnace at 300°C and 100 mL / min in an air atmosphere for 4 h, and the resulting black solid is named C@NMSS.

[0042] (2) Preparation of Zn-Zr / C@NMSS catalysts with different loadings:

[0043] The Zn-Zr / C@NMSS catalysts with different loadings were impregnated with aqueous solutions of zinc nitrate and zirconium oxynitrate for 12 h. The Zn loading was 0.5%, and the Zr loading was 2% and 4%. After drying at 80 °C for 8 h, the samples were calcined in a tube furnace at 550 °C and 100 mL / min nitrogen atmosphere for 4 h to obtain Zn-Zr / C@NMSS catalysts with different loadings.

[0044] Example 2

[0045] The preparation of NC-modified Zn-Zr-based catalysts with different types of supports includes the following steps:

[0046] The preparation process is similar to that in Example 1, with Zn loading of 0.5% and Zr loading of 2%. The difference is that the support is replaced with deAl-beta, MFI, MWW, SBA-15 and gaseous SiO2. The gaseous SiO2 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., and SBA-15 and MFI were purchased from Nankai Catalyst Factory. All the above supports were used directly after purchase without further processing.

[0047] The synthesis method of MWW is as follows: Deionized water, silica, boric acid, and piperidine (PI) are mixed and stirred evenly to form a synthetic gel with the composition 1SiO2:1.4PI:1.33H3BO3:19H2O. This gel is then crystallized in a rotary oven at 130℃ for 1 day, 150℃ for 1 day, and 170℃ for 5 days. The resulting sample is filtered, washed, dried at 80℃, and calcined at 550℃ for 4 hours to obtain the MWW-B sample. The MWW-B sample is then mixed with 6mol / L nitric acid (solid-liquid ratio 1g / 20mL), refluxed at 100℃ for 20 hours, dried at 80℃, and calcined at 550℃ for 4 hours, denoted as MWW.

[0048] The deAl-beta synthesis method is as follows: A beta sample with a silicon-to-aluminum ratio of 12.5 was purchased from Nankai Catalyst Factory and subjected to dealuminization treatment. The beta was mixed with 16 mol / L nitric acid (solid-to-liquid ratio 1 g / 20 mL), refluxed at 80 °C for 24 h, dried at 80 °C, and calcined at 550 °C for 4 h to obtain deAl-beta.

[0049] Comparative Example 3

[0050] The preparation of non-NC-modified Zn-Zr-based catalysts with different types of supports includes the following steps:

[0051] The preparation process is similar to that in Example 2, except that urea is not added, but only zinc nitrate and zirconium oxynitrate are added.

[0052] Example 3

[0053] The preparation of NC-modified catalysts with different active components on the same support includes the following steps:

[0054] The preparation process is similar to that in Example 1. The metal precursors M1 are copper nitrate (copper loading of 0.5%), silver nitrate (silver loading of 0.5%), and zinc nitrate (zinc loading of 0.5%), respectively. The metal precursors M2 are zirconium oxynitrate (zirconium loading of 2%), hafnium chloride (hafnium loading of 2%), tantalum chloride (tantalum loading of 2%), and yttrium chloride (yttrium loading of 2%), respectively.

[0055] Comparative Example 4

[0056] Preparation of non-NC-modified catalysts with different active components on the same support:

[0057] The preparation process is similar to that in Example 3, except that urea is not added.

[0058] Example 4

[0059] Evaluation process of the ethanol-to-butadiene catalyst: 0.25 g of the catalyst prepared in the above example was granulated and packed into a fixed-bed reactor. The feedstock was introduced into the reactor by pump feeding and carrier gas (flow rate of 40 mL / min). The ethanol feed rate was 0.005 mL / min, and the reaction space velocity (WHSV) was 0.96 h⁻¹. -1 The reaction temperature is 350℃.

[0060] Methods for calculating reaction conversion rate and selectivity:

[0061] 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%

[0062] Butadiene selectivity (%) = 2n 产物中丁二烯 / (n 反应前的乙醇 -n 反应后剩余乙醇 )*100%

[0063] Example 5

[0064] The performance of Zn-Zr / NC@NMSS catalysts with different loadings in Example 1 was evaluated under the same reaction conditions as in Example 4. The results are shown in Table 1.

[0065] Table 1 Catalytic performance of Zn-Zr / NC@NMSS catalysts with different loadings in Example 1

[0066]

[0067] The reaction results show that when the Zn loading is fixed at 0.5%, the Zr loading of 2-8% has relatively good catalytic performance. Among them, the active component Zr loading of 4% has better catalytic performance, and the butadiene selectivity can reach more than 70%. As the Zr content increases, the conversion rate gradually increases and the butadiene selectivity gradually decreases.

[0068] Example 6

[0069] The performance of Zn-Zr / NMSS with different loadings in Comparative Example 1 was evaluated under the same reaction conditions as in Example 4. The results are shown in Table 2.

[0070] Table 2 shows the catalytic performance of Zn-Zr / NMSS catalysts with different loadings in Comparative Example 1.

[0071]

[0072] As can be seen from the comparison in Table 1-2, under the same Zr loading, the ethanol conversion rate and butadiene selectivity of the Zn-Zr / NC@NMSS catalyst of the present invention are higher than those of the catalyst without nitrogen and carbon modification, which demonstrates the uniqueness and superiority of the present invention.

[0073] Example 7

[0074] The performance of the catalysts in Example 1 and Comparative Examples 1-2 was evaluated under the same reaction conditions as in Example 4, and the results are shown in Table 3.

[0075] Table 3 Comparison of catalytic performance of the catalysts in Example 1 and Comparative Examples 1-2

[0076]

[0077] The comparison of the performance of several catalysts in the table shows that, under the same Zn and Zr loading, the ethanol conversion rate and butadiene selectivity of the NC-modified catalyst of this invention are higher than those of the catalyst without nitrogen and carbon modification and the catalyst with only C modification. Although the C-modified catalyst has improved the selectivity of butadiene, the conversion rate is reduced. This demonstrates the uniqueness and superiority of the NC modification strategy proposed in this invention.

[0078] Example 8

[0079] In Example 2 and Comparative Example 3, the catalyst performance was evaluated by changing the support under the same Zr and Zn loadings. The reaction conditions were the same as in Example 4, and the results are shown in Table 4.

[0080] Table 4. Catalytic performance of catalysts with different supports in Example 2 and Comparative Example 3.

[0081]

[0082]

[0083] As can be seen from the table, the catalyst performance of different silicon-based supports was improved after nitrogen-carbon modification. This improvement primarily reduced the selectivity for dehydration products such as ethylene and increased the further conversion of the intermediate acetaldehyde, thus enhancing the selectivity for butadiene. Furthermore, the conversion rate of ethanol was also improved. In summary, the NC modification strategy is applicable to most silicon-based support systems, demonstrating its universality and highlighting the superiority and uniqueness of this invention.

[0084] Example 9

[0085] The catalytic performance of 0.5% Zn-2% Zr / NC@NMSS was investigated at different reaction temperatures. The reaction space velocity and feed flow rate were the same as in Example 4. The results are shown in Table 5.

[0086] Table 5 Catalytic performance of 0.5% Zn-2% Zr / NC@NMSS catalyst

[0087]

[0088] As can be seen from the table, the 0.5%Zn-2%Zr / NC@NMSS catalyst provided by this invention can react at a relatively low temperature (275℃), and can ensure high butadiene selectivity (>60%) and conversion rate (>50%) above 350℃. At higher temperatures, it can even achieve 100% conversion with high selectivity (>60%), demonstrating the superiority of this invention.

[0089] Example 10

[0090] The catalytic performance of 0.5% Zn-2% Zr / NC@NMSS under different space velocities was investigated. The reaction conditions were the same as in Example 4, except that the reaction space velocity was changed. The results are shown in Table 6.

[0091] Table 6 Catalytic performance of 0.5% Zn-2% Zr / NC@NMSS catalyst

[0092] <![CDATA[WHSV(h -1 )]]> Ethanol conversion rate (%) Butadiene selectivity (%) 0.38 100 70 0.96 79 65 1.92 55 52 3.84 40 41

[0093] The data in the table show that the catalyst provided by this invention exhibits good reaction performance at different reaction space velocities (WHSVs), with the best performance at a WHSV of 0.38 h⁻¹. -1 When the time is right, the optimal catalytic effect can be achieved.

[0094] Example 11

[0095] The stability of 0.5% Zn-4% Zr / NMSS and 0.5% Zn-4% Zr / NC@NMSS was investigated under the same reaction conditions as in Example 4. The results are shown in Appendix. Figure 1 and Figure 2 As shown in the figure, the conversion rate of 0.5% Zn-4% Zr / NMSS decreased from 75% to 65% within 120 h, indicating significant deactivation. In contrast, 0.5% Zn-4% Zr / NC@NMSS not only achieved a higher conversion rate (over 90%) but also maintained an ethanol conversion rate of over 85% within 250 h, with butadiene selectivity remaining above 60%. This demonstrates that the NC-modified catalyst exhibits significantly higher activity and stability than the unmodified catalyst, showcasing the superiority of the NC modification strategy.

[0096] In summary, the ethanol-to-butadiene catalyst prepared by the nitrogen-carbon modification strategy of urea-assisted pyrolysis in this invention can achieve high activity, high selectivity, and high stability in the preparation of butadiene. Moreover, this method is universal and applicable to most metal-silicon-based support systems. It can also be mass-produced and is easy to industrialize, thus having broad application prospects.

Claims

1. The application of a nitrogen-carbon modified catalyst for the catalytic conversion of ethanol to butadiene in the reaction of ethanol to butadiene, characterized in that, The reaction was carried out in an atmospheric pressure fixed-bed reactor with a reaction space velocity (WHSV) ranging from 0.12 to 10 h⁻¹. -1 Using inert gas as the carrier gas, the carrier gas space velocity (GSHV) is 500-10000 h⁻¹. -1 The reaction temperature is 200-500℃; The catalyst is represented by the formula M1-M2 / NC@support, where M1 and M2 are active components, M1 is Zn, M2 is oxidized Zr, NC represents the nitrogen and carbon modification of the catalyst, and support is a silicon-based support. The loading of M1 element in the catalyst is 0.4-10 wt%; the loading of M2 element in the catalyst is 1-50 wt%; the loading of nitrogen element in the catalyst is 1-15 wt%; and the loading of carbon element in the catalyst is 2-15 wt%. The catalyst preparation method includes the following steps: impregnating a solution containing soluble salts of active components M1 and M2 and a soluble nitrogen and carbon source onto a silicon-based support, drying it, and then calcining it in an inert gas at a calcination temperature of 350-750°C. o C, roasting time is 1-24 hours, then it is obtained.

2. The application according to claim 1, characterized in that, The silicon-based support is a silicon-based molecular sieve or porous silica. The silicon-based molecular sieve includes one or more of SBA-15, SBA-16, silicate-1, deAl-beta, MCM-41, MWW, and NMSS. The porous silica includes one or more of silica, silica sol, and mesoporous silica, and the specific surface area of ​​the porous silica is >20 m². 2 / g.

3. The application according to claim 2, characterized in that, The preparation method of NMSS silica-based molecular sieve is as follows: 90-100 mL of a 15-35 wt% hexadecyltrimethylammonium chloride aqueous solution is added to 120-180 mL of ultrapure water, followed by 0.5-0.9 g of triethanolamine. The mixture is stirred until homogeneous and then stirred at 50-70℃ for 0.5-5 hours. 50-100 mL of a 10-30% volume percentage tetraethyl orthosilicate / cyclohexane solution is slowly added. After continuous stirring at 60-80℃ for 10-20 hours, the upper oil phase of cyclohexane is removed. The mixture is then heated to 90-95℃ and aged for 2-5 hours. The resulting solid is centrifuged, washed, and dried, and then calcined at 600-700℃ for 2-8 hours.

4. The application according to claim 1, characterized in that, The soluble salts of the active components M1 and M2 are one or more of the following: nitrates, chlorides, oxynitrates, oxychlorides, and organic alkoxides of the corresponding metals; the nitrogen and carbon sources are one or more of the following: urea, cyanamide, dicyandiamide, melamine, thiourea, isobutyramide, dicarboxyhydrazide, and dopamine; and the inert gas is one or more of the following: nitrogen, argon, and helium.

5. The application according to claim 1, characterized in that, The drying temperature is 60-200℃, the calcination temperature is 500-600℃, and the calcination time is 2-6 hours.

6. The application according to claim 1, characterized in that, The reaction temperature is 300-400℃, and the reaction space velocity range is WHSV = 0.25-6 h⁻¹. -1 The inert gas is one or more of nitrogen, argon, and helium, and the carrier gas space velocity is 1000-5000 h⁻¹. -1 .

7. The application according to claim 6, characterized in that, During the reaction, the ethanol conversion rate was 40-100%, and the selectivity of 1,3-butadiene product was 50-80%.

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