A ternary metal oxide catalyst for hydrogen production by high-temperature methanol reforming, and a preparation method and application thereof

Abstract

The application relates to a high-temperature-resistant methanol reforming hydrogen production catalyst as well as a preparation method and application thereof, and belongs to the field of chemical engineering and energy. w M m Zr y O z Wherein M is selected from one of Ce, Re, Y, La, Ga and In. Compared with a traditional CuO / ZnO / Al2O3 catalyst, the ternary metal oxide catalyst can effectively improve product selectivity and high-temperature thermal stability. The methanol conversion rate of the catalyst can reach 99.8% at a reaction temperature of 400 DEG C, and the catalyst can be stably operated for a long time at 400 DEG C and 9.0h ‑1 -1 under high temperature and high air speed. The catalyst has the advantages of high activity, low CO selectivity and good stability under high temperature and high air speed.

Description

Technical Field

[0001] This invention belongs to the field of chemical engineering and energy, specifically relating to a ternary metal oxide catalyst for hydrogen production by high-temperature methanol steam reforming, its preparation method, and its application. Background Technology

[0002] Hydrogen energy, as a green energy source with abundant reserves, high calorific value, high energy density, and diverse sources, is hailed as an ideal clean energy source for the 21st century. To address the challenges of hydrogen storage and transportation, researchers have proposed a strategy to produce high-purity hydrogen using liquid organic hydrogen carriers. Methanol, as an ideal hydrogen storage feedstock, is widely used in proton exchange membrane fuel cells and stationary hydrogen refueling stations due to its high hydrogen-to-carbon ratio and low price. The mixed gas (including carbon dioxide, hydrogen, and carbon monoxide) obtained from methanol steam reforming can be separated into high-purity hydrogen using a palladium membrane. To prevent palladium membrane embrittlement, the operating temperature is typically around 400℃.

[0003] Currently, there are three main types of catalysts used for methanol steam reforming to produce hydrogen: copper-based catalysts, noble metal catalysts, and metal oxide catalysts. Copper-based catalysts have high activity but poor stability and are prone to high-temperature sintering. Copper-based catalysts generally use Cu as the active center; for example, CuO / ZnO / Al2O3 catalysts are widely used in methanol reforming reactions. However, their operating temperature is generally below 300℃, as higher temperatures cause CuO to sinter, reducing its stability. Catalysts containing noble metals also have high activity and selectivity, and their operating temperature is generally around 200℃. However, noble metals are expensive, hindering large-scale industrial production and use. Metal oxide catalysts (containing no noble metals or Cu) are commonly used in high-temperature methanol reforming reactions. For example, ZnCr2O4 spinel, ZnO-Al2O3, and ZnO / ZrO2 solid solutions all exhibit high activity at 400℃. Compared to copper-based and noble metal catalysts, metal oxide catalysts exhibit high stability at high temperatures. However, they are prone to side reactions such as direct methanol decomposition and reverse water-gas shift reaction at high temperatures, often resulting in the production of carbon monoxide. Excessive carbon monoxide content can poison the platinum electrode of fuel cells. Therefore, developing catalysts with high activity, high selectivity, and high stability at high temperatures is extremely challenging. Summary of the Invention

[0004] Based on the above technical problems, this invention develops a metal oxide catalyst that can be used for high-temperature methanol steam reforming. This type of catalyst has high activity and selectivity at high temperatures, and due to the stability of the structure of the metal oxide catalyst itself and its excellent anti-carbon deposition performance, this catalyst also has the advantages of strong heat resistance, anti-sintering, and good stability.

[0005] According to one aspect of this application, a ternary metal oxide catalyst is provided, the ternary metal oxide catalyst having a composition of Zn. w M m Zr y O z M is selected from one of Ce, Re, Y, La, Ga, and In.

[0006] Optionally, in the ternary metal oxide catalyst, the molar amount of zinc accounts for 4% to 25% of the total molar amount of zinc, M, and zirconium, and the molar amount of M accounts for 1% to 20% of the total molar amount of zinc, M, and zirconium.

[0007] Optionally, in the ternary metal oxide catalyst, the upper limit of the molar amount of zinc as a percentage of the total molar amount of all metal elements is selected from 24%, 23%, 22%, 20%, 18%, 16%, 15%, or any value between any two of the above; the lower limit is selected from 5%, 6%, 8%, 10%, 12%, 15%, or any value between any two of the above.

[0008] Optionally, in the ternary metal oxide catalyst, the upper limit of the molar amount of element M relative to the total molar amount of all metal elements is selected from 18%, 17%, 16%, 15%, 12%, 10%, or any value between any two of the above points; the lower limit is selected from 2%, 4%, 5%, 6%, 8%, 10%, or any value between any two of the above points.

[0009] Optionally, the specific surface area of ​​the ternary metal oxide catalyst is 47–62 m². 2 / g.

[0010] According to one aspect of this application, a method for preparing the above-mentioned ternary metal oxide catalyst is provided, the preparation method comprising method one or method two;

[0011] Method 1:

[0012] (1) Solution I containing M metal salt, zirconium source and precipitant is reacted to obtain MZr hydroxide precursor;

[0013] (2) The solution I' containing the zinc source is impregnated into the MZr hydroxide precursor to obtain the ternary metal oxide catalyst;

[0014] Method 2:

[0015] (i) Solution II containing zirconium source and precipitant is reacted with reaction II to obtain Zr hydroxide precursor;

[0016] (ii) Impregnate the solution II' containing the M metal salt and zinc source into the Zr hydroxide precursor to obtain the ternary metal oxide catalyst.

[0017] Optionally, solution I is obtained by mixing solution a containing metal salt M and zirconium source with solution b containing precipitant;

[0018] Solution II is obtained by mixing solution c containing a zirconium source with solution d containing a precipitant.

[0019] In this application, the solution containing the zirconium source is prepared by heating and stirring at 60–80 °C.

[0020] Optionally, the mixing temperature of solution a and solution b is 60–80°C;

[0021] The volume ratio of solution a to solution b is 1 to 4; in solution a, the concentration of metal element M is 0 to 0.10 mol / L (excluding 0), and the concentration of zirconium element is 0.1 to 0.2 mol / L.

[0022] Optionally, after mixing solution a and solution b, the pH is adjusted to 8-8.5 to obtain precipitate I;

[0023] The precipitate I was stirred at 300-600 r / min for 5-20 min at 60-80°C.

[0024] Optionally, the mixing temperature of solution c and solution d is 60–80°C;

[0025] The volume ratio of solution c to solution d is 1 to 4; the concentration of zirconium in solution c is 0.1 to 0.2 mol / L.

[0026] Preferably, after mixing solution c and solution d, the pH is adjusted to 8-8.5 to obtain precipitate II;

[0027] The precipitate II was stirred at 300-600 r / min for 5-20 min at 60-80°C.

[0028] Optionally, in the solution II', the concentration of metal element M is 0 to 0.10 mol / L (excluding 0).

[0029] Optionally, the M metal salt is selected from at least one of the nitrate, sulfate, acetate, and ammonium salts corresponding to the M metal; the M metal is selected from one of Ce, Re, Y, La, Ga, and In.

[0030] Optionally, the zirconium source is selected from at least one of zirconium oxynitrate, zirconium nitrate pentahydrate, and zirconium oxychloride.

[0031] Optionally, the precipitant is selected from at least one of ammonium carbonate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, potassium hydroxide, sodium hydroxide, and ammonia water.

[0032] Optionally, the zinc source is selected from at least one of zinc acetate and zinc nitrate.

[0033] Optionally, in step (2), the amount of zinc source used for each 1g MZr hydroxide precursor is 0.08 to 2 mmol.

[0034] Optionally, in step (2), the upper limit of the amount of zinc source used for each 1g MZr hydroxide precursor is selected from 1.8mmol, 1.5mmol, 1.2mmol, 1mmol, 0.8mmol, 0.6mmol, or any value between any two of the above; the lower limit is selected from 0.1mmol, 0.2mmol, 0.3mmol, 0.5mmol, 0.6mmol, or any value between any two of the above.

[0035] Optionally, in step (ii), the amount of zinc source used for each 1g Zr hydroxide precursor is 0.08 to 2 mmol.

[0036] Optionally, in step (ii), the upper limit of the amount of zinc source used per 1g Zr hydroxide precursor is selected from 1.8mmol, 1.5mmol, 1.2mmol, 1mmol, 0.8mmol, 0.6mmol, or any value between any two of the above; the lower limit is selected from 0.1mmol, 0.2mmol, 0.3mmol, 0.5mmol, 0.6mmol, or any value between any two of the above.

[0037] Optionally, when the precipitant is selected from at least one of ammonium carbonate or sodium carbonate, the concentration of the precipitant in solution b and solution d is independently 0.1 to 0.2 mol / L;

[0038] When the precipitant is selected from at least one of sodium bicarbonate, potassium carbonate, potassium bicarbonate, potassium hydroxide, or sodium hydroxide, the concentration of the precipitant in solution b and solution d is independently 0.2–0.4 mol / L.

[0039] When the precipitant is selected from ammonia, the volume concentration of the precipitant in solution b and solution d is independently 10% to 20%.

[0040] Optionally, in Method 1 and Method 2, the impregnation involves first grinding and stirring, then allowing it to stand for impregnation; after impregnation, the catalyst is dried and calcined to obtain the ternary metal oxide catalyst.

[0041] Optionally, the grinding and stirring time is 5 to 15 minutes;

[0042] The soaking time is 6–12 hours;

[0043] The drying temperature is 80–120°C;

[0044] The calcination temperature is 450–550°C, and the time is 3–6 hours; the calcination atmosphere is air.

[0045] According to one aspect of this application, a method for producing hydrogen by high-temperature methanol steam reforming is provided, wherein a feedstock containing methanol and water is reacted with a ternary metal oxide catalyst, wherein the ternary metal oxide catalyst is selected from at least one of the above-mentioned ternary metal oxide catalysts or ternary metal oxide catalysts prepared by the above-mentioned preparation method.

[0046] Optionally, the reaction is carried out under normal pressure, at a temperature of 350–420°C, and with a mass hourly space velocity (HHSV) of 1.2–9.0 h⁻¹. -1 .

[0047] Optionally, the molar ratio of water to methanol is 1.0 to 1.6; the dilution gas for the reaction is nitrogen, and the flow rate of the dilution gas is 5 to 30 mL / min.

[0048] Optionally, the ternary metal oxide catalyst is subjected to reduction treatment before use.

[0049] Optionally, the reduction process is carried out at 200–450°C for 2–6 hours in a hydrogen-containing atmosphere.

[0050] Optionally, the hydrogen gas component in the hydrogen-containing atmosphere is 10% to 100%.

[0051] As one embodiment of this application, a method for preparing the above-mentioned ternary metal oxide catalyst is provided, comprising the following steps:

[0052] Step 1: Prepare an aqueous solution A containing M metal salt and zirconium source; mix aqueous solution A with aqueous solution B containing precipitant at 60-80℃, adjust pH to 8-8.5 to obtain precipitate, dry at 80-120℃ to obtain MZr hydroxide precursor;

[0053] In the aqueous solution A, the concentration of metal element M is 0–0.10 mol / L (excluding 0), and the concentration of zirconium is 0.1–0.2 mol / L.

[0054] The precipitant is ammonia water, and the volume concentration of the precipitant in solution B is 10% to 20%.

[0055] Step 2: Prepare an aqueous solution C containing a zinc source; drop the aqueous solution C onto the surface of the MZr hydroxide precursor, grind and stir for 5-15 min, let it stand and soak for 6-12 h, dry it at 80-120℃, and calcine it at 450-550℃ for 3-6 h to obtain the ternary metal oxide catalyst.

[0056] The amount of zinc source used for each 1g of MZr hydroxide precursor is 0.08–2 mmol.

[0057] The ternary metal oxide catalyst described in this application exhibits the best catalytic performance at a reaction temperature of 400°C, achieving near-complete conversion of methanol and low CO selectivity. Furthermore, it performs well at a high space velocity (9.0 h⁻¹) at 400°C. -1 It runs smoothly and maintains good stability.

[0058] The beneficial effects that this application can produce include:

[0059] This invention discloses a ternary metal oxide catalyst for high-temperature methanol steam reforming reaction, its preparation method, and its application. The catalyst composition is Zn. w M m Zr y O z M is represented by Ce, Re, Y, La, In, etc. The catalyst exhibits high conversion rate and low CO selectivity at high temperatures, and can be used at 400℃ for 9.0 h. -1 Under long-term stable operation, the methanol conversion rate can reach 99.8%, overcoming the shortcomings of metal oxide catalysts that are prone to phase change and carbon deposition at high temperatures. This catalyst has the advantages of high activity, good selectivity, good thermal stability, resistance to carbon deposition, and good stability at high temperature and high space velocity, making it a high-performance high-temperature methanol steam reforming hydrogen production catalyst. Attached Figure Description

[0060] Figure 1 In the image, (a) represents the Zn1Ce1Zr9O described in Embodiment 2 of this application. x The methanol conversion rate and CO selectivity of the catalyst as a function of reaction time are shown in Figure (b). Detailed Implementation

[0061] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0062] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially.

[0063] The analysis method in the embodiments of this application is as follows:

[0064] Online analysis of the eluent gas was performed using an Agilent gas chromatograph equipped with dual detectors of TCD and FID. The packed column was a TDX-01, and the capillary column was a TG BOND Q.

[0065] In the embodiments of this application, the conversion rate and selectivity are calculated as follows:

[0066] In the embodiments of this application, the methanol conversion rate and product selectivity are calculated based on the number of carbon moles.

[0067] Methanol conversion rate: C1 and C2 represent the molar amounts of methanol entering and exiting, respectively.

[0068] Product selectivity: Where xi represents the molar percentage of product i; ni represents the number of carbon atoms in product i.

[0069] Example 1

[0070] Weigh 0.05 mol Zr(NO3)4·5H2O and 3.1 mmol Ce(NO3)3·6H2O and dissolve them in 500 mL of deionized water. Heat and stir at 70 °C to dissolve, obtaining a mixed solution. Separately, measure 20 mL of ammonia water and dilute it to 200 mL of deionized water. Quickly add the diluted ammonia solution to the above mixed solution to adjust the pH to 8.3. Continue stirring the resulting precipitate at 70 °C for 10 min at a stirring speed of 500 r / min. Then, allow the resulting precipitate to cool to room temperature, filter, and wash three times with deionized water until the filtrate is neutral. Dry the resulting filter cake overnight at 100 °C to obtain Ce. 0.5 Zr9(OH) x Precursor.

[0071] Weigh 1.3 mmol of Zn(NO3)2·6H2O and dissolve it in 0.5 ml of deionized water to obtain a Zn solution. Weigh 2 g of Ce. 0.5 Zr9(OH) x The precursor was placed in an evaporating dish, and the Zn solution was added dropwise to Ce. 0.5 Zr9(OH) x The precursor was ground and stirred for 5 min, then impregnated at room temperature for 7 h, dried at 100 °C, and finally calcined in an air atmosphere in a muffle furnace at 500 °C for 4 h. The resulting catalyst was designated Zn1Ce. 0.5 Zr9O x .

[0072] The catalyst was tableted, crushed, and sieved to a mesh size of 40–80 for evaluation. 0.3 g of the sieved catalyst was weighed and placed in a reaction tube with an inner diameter of 6 mm. Reduction was carried out at 400 °C in hydrogen gas for 2 h at a hydrogen flow rate of 20 mL / min. The reaction was conducted under normal pressure, using a methanol and water mixture as the feedstock, where n(MeOH):n(H₂O) = 1.0. Nitrogen was used as the dilution gas at a flow rate of 30 mL / min. The reaction temperature was 400 °C, and the mass hourly space velocity (H₂S₀) was 4.5 h⁻¹. -1 The catalyst evaluation results are shown in Table 1.

[0073] Example 2

[0074] The metal salt used in the catalyst preparation was 6.2 mmol Ce(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.2 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was designated Zn1Ce1Zr9O. x The catalyst evaluation results are shown in Table 1.

[0075] Example 3

[0076] The metal salt used in the catalyst preparation was 12.4 mmol Ce(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.1 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was designated Zn1Ce2Zr9O. x The catalyst evaluation results are shown in Table 1.

[0077] Example 4

[0078] The metal salt used in the catalyst preparation was 6.2 mmol Ce(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.8 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was denoted as Zn. 1.5 Ce1Zr9O x The catalyst evaluation results are shown in Table 1.

[0079] Example 5

[0080] The metal salt used in the catalyst preparation was 6.2 mmol Ce(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 3.2 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was denoted as Zn. 2.5 Ce1Zr9O x The catalyst evaluation results are shown in Table 1.

[0081] Example 6

[0082] The metal salt used in the catalyst preparation was 3.1 mmol NH4ReO4, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.3 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was designated Zn1Re. 0.5 Zr9O x The catalyst evaluation results are shown in Table 1.

[0083] Example 7

[0084] The metal salt used in the catalyst preparation was 3.1 mmol Y(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.3 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was designated Zn1Y. 0.5 Zr9O x The catalyst evaluation results are shown in Table 1.

[0085] Example 8

[0086] The metal salt used in the catalyst preparation was 3.1 mmol La(NO3)3·6H2O, the zirconium source was 0.05 mol Zr(NO3)4·5H2O, and the zinc source was 1.3 mmol Zn(NO3)2·6H2O. Other preparation and evaluation steps were the same as in Example 1. The resulting catalyst was designated Zn1La. 0.5 Zr9O x The catalyst evaluation results are shown in Table 1.

[0087] Example 9

[0088] Weigh 35.0 g of Zr(NO3)4·5H2O and dissolve it in 500 mL of deionized water. Heat and stir at 70 °C to dissolve, obtaining a Zr solution. Separately, measure 21.0 mL of ammonia solution and dilute it in 200 mL of deionized water. Quickly add the diluted ammonia solution to the Zr solution. Continue stirring the resulting precipitate at 70 °C for 10 min at a stirring speed of 500 r / min. Then, allow the resulting precipitate to cool to room temperature, filter it, and wash it three times with deionized water until the filtrate is neutral. Dry the resulting filter cake overnight at 100 °C to obtain the Zr(OH)4 precursor.

[0089] The metal salts used in the impregnation process were 1.2 mmol Zn(NO3)2·6H2O and 0.1 mmol Ga(NO3)3. Zn(NO3)2·6H2O and Ga(NO3)3 were dissolved in 1 mL of deionized water to obtain a mixed solution. This mixed solution was dropwise added to 2 g of Zr(OH)4 precursor, ground and stirred for 5 min, then impregnated at room temperature for 7 h, dried at 100 °C, and finally calcined in an air atmosphere in a muffle furnace at 500 °C for 4 h. The resulting catalyst was designated Zn1Ga. 0.1 Zr 10 O x The evaluation steps were the same as in Example 1, and the catalyst evaluation results are shown in Table 1.

[0090] Example 10

[0091] The metal salt used in the catalyst preparation was 1.2 mmol In(NO3)3·5H2O, the zirconium source was 0.08 mol Zr(NO3)4·5H2O, and the zinc source was 1.2 mmol Zn(NO3)2·6H2O. Other preparation steps were the same as in Example 9. The resulting catalyst was designated Zn1In1Zr. 10 O x The evaluation steps were the same as in Example 1, and the catalyst evaluation results are shown in Table 1.

[0092] Comparative Example 1

[0093] The catalyst was prepared using 1.2 mmol of zinc nitrate and 2 g of Zr(OH)4 precursor, with the precursor preparation method being the same as in Example 9. Zn(NO3)2·6H2O was dissolved in 1 mL of deionized water to obtain a zinc solution. The zinc solution was then dropped onto 2 g of Zr(OH)4 precursor, ground and stirred for 5 min, then impregnated at room temperature for 7 h, dried at 100 °C, and finally calcined in a muffle furnace at 500 °C for 4 h. The resulting catalyst was denoted as 9% ZnO / ZrO2 (9% refers to the percentage of zinc molar amount relative to the total molar amount of zinc and zirconium). The evaluation steps were the same as in Example 1, and the catalyst evaluation results are shown in Table 1.

[0094] Comparative Example 2

[0095] The commercial CuO / ZnO / Al2O3 catalyst (SCST-401 from Sichuan Shutai Chemical Technology Co., Ltd.) was evaluated using the same procedure as in Example 1. The catalyst evaluation results are shown in Table 1.

[0096] Table 1. Catalyst Evaluation Results of Examples and Comparative Examples

[0097]

[0098] As shown in Comparative Example 2, traditional copper-based catalysts exhibit relatively high methanol conversion rates at high temperatures, but these are often accompanied by significant CO production. Therefore, maintaining high methanol conversion rates while reducing CO selectivity at high temperatures is extremely challenging. Examples 1-10 demonstrate that the ternary metal oxide catalyst described herein exhibits a high methanol conversion rate at 400°C and demonstrates a significant advantage over copper-based catalysts in reducing CO selectivity. Therefore, compared to traditional CuO / ZnO / Al2O3 catalysts, the ternary metal oxide catalyst described in this invention can effectively improve product selectivity.

[0099] Figure 1 The graphs show the stability test results for the catalysts in Example 2 and Comparative Example 1. The stability test reaction conditions were: atmospheric pressure, 400°C, and a mass hourly space velocity (H₂Sv) of 9.0 h⁻¹. -1 Water:Methanol (mol / mol) = 1.0. From Figure 1 As can be seen from (b) above, the 9% ZnO / ZrO2 catalyst at 400℃ for 9.0 h... -1 After running for 225 hours, the conversion rate decreased by nearly 30%. At high temperatures, metal oxide catalysts often experience phase transitions and carbon buildup, leading to reduced activity. Figure 1 As can be seen from (a) in the figure, Zn1Ce1Zr9O x The catalyst maintained good stability under the same harsh conditions, with only a 5% decrease in methanol conversion after 250 hours of operation. Therefore, the stability of the catalyst was significantly improved after Ce doping, indicating that the ternary metal oxide catalyst has good thermal stability and can effectively suppress carbon deposition.

[0100] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for producing hydrogen by high-temperature methanol steam reforming, characterized in that, Raw materials containing methanol and water react with a ternary metal oxide catalyst. The composition of the ternary metal oxide catalyst is Zn1Ga 0.1 Zr 10 O x .

2. The method according to claim 1, characterized in that, The reaction was carried out under normal pressure at a temperature of 350–420 °C and a mass hourly space velocity (HHSV) of 1.2–9.0 h⁻¹. -1 ; The molar ratio of water to methanol is 1.0 to 1.6; The diluent gas used in the reaction is nitrogen, and the flow rate of the diluent gas is 5~30 mL / min.

3. The method according to claim 1, characterized in that, The ternary metal oxide catalyst is subjected to reduction treatment before use; The reduction process is carried out in a hydrogen-containing atmosphere at 200-450°C for 2-6 hours. The hydrogen gas fraction in the hydrogen-containing atmosphere is 10% to 100%.

4. The method according to claim 1, characterized in that, The ternary metal oxide catalyst was prepared by a method comprising the following steps: (i) React a solution containing a zirconium source and a precipitant to obtain a Zr hydroxide precursor; (ii) Immerse the Zr hydroxide precursor in a solution containing gallium salt and zinc source; The impregnation process involves grinding and stirring first, followed by standing impregnation; after impregnation, the catalyst is dried and calcined to obtain the ternary metal oxide catalyst.

5. The method according to claim 4, characterized in that, The grinding and stirring time is 5-15 minutes; The soaking time is 6-12 hours; The drying temperature is 80~120℃; The calcination temperature is 450~550℃, and the time is 3~6h.

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