Aluminum-doped NiCoCe catalyst, preparation method thereof and application of aluminum-doped NiCoCe catalyst in low-temperature CO2 hydrogenation methane preparation reaction

Abstract

The invention provides an aluminum-doped NiCoCe catalyst, a preparation method thereof and application of the aluminum-doped NiCoCe catalyst in low-temperature CO2 hydrogenation methane preparation reaction, the preparation method comprises the following steps: (1) dissolving nickel nitrate, cobalt nitrate, cerium nitrate, aluminum nitrate and an alkaline precipitator in deionized water, and fully stirring the solution at room temperature to obtain a solution A; (2) putting the solution A into a reaction kettle, and crystallizing the mother liquid at a constant temperature for a certain time to obtain a solid-liquid mixture B; (3) centrifuging and washing the solid-liquid mixture B in the step (2) to obtain a precipitate C; (4) drying the precipitate C in the step (3) to obtain a precursor D; and (5) reducing and passivating the precursor D in the step (4) to obtain the catalyst. The catalyst prepared by the invention effectively solves the problem of low CO2 conversion rate in low-temperature CO2 methanation reaction, lattice distortion is promoted by introducing the Al element, the migration ability of lattice oxygen is increased, and the formation of a large number of oxygen vacancies is beneficial to improving the oxidation-reduction property of the catalyst.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of catalyst preparation, and particularly relates to an aluminum-doped NiCoCe catalyst, a preparation method thereof, and application of the catalyst in a low-temperature CO2 hydrogenation reaction to produce methane. BACKGROUND

[0002] CO2 methanation converts CO2 captured by chemical looping combustion technology and H2 produced by water electrolysis of renewable energy into clean fuel methane, and methane combustion changes carbon, oxygen and hydrogen, thus forming a green and clean energy cycle, enabling captured CO2 to be converted into reusable energy instead of being discharged into the atmosphere, thereby helping to reduce greenhouse gas emissions and forming low-carbon transportation fuel, and being an effective solution to achieve carbon neutrality.

[0003] Ni-based catalysts have defects such as instability under heat, easy carbon deposition, and deactivation of flowing carbonyl Ni species due to the interaction of metal particles with CO at a lower temperature; the activity of Co-based catalysts generally increases with increasing temperature, but the reaction kinetics is limited at low temperature, and a higher temperature is required to achieve an ideal conversion rate. Therefore, the research prospect of improving the CO2 methanation reaction performance of NiCo bimetallic catalysts at low temperature is broad. At low temperature, the oxygen vacancies on the surface of the catalyst are quite different from those at high temperature, and these factors affect the adsorption and activation of CO2 and H2, the catalytic activity and the reaction path. Therefore, the influence of the regulation of the oxygen vacancies on the surface of the catalyst on the structure, surface properties and low-temperature activity of the CO2 methanation catalyst and the mechanism of action need to be systematically studied.

[0004] The catalytic effect of the CO2 methanation catalyst prepared by the traditional hydrothermal method is poor, and there are problems such as low catalytic reaction activity at low temperature and poor catalytic performance. Therefore, it is necessary to design a new method to achieve a breakthrough in regulating oxygen vacancies to improve the catalytic performance of the CO2 methanation catalyst at low temperature, so as to solve the above problems. SUMMARY

[0005] The application aims to overcome the defects of the prior art, and provides an aluminum-doped NiCoCe catalyst, a preparation method thereof, and application of the catalyst in a low-temperature CO2 hydrogenation reaction to produce methane, effectively solving the problems of poor effect of the CO2 methanation catalyst prepared by the traditional method and low CO2 conversion rate at low temperature.

[0006] The application provides the following technical solutions:

[0007] The application provides a preparation method of an aluminum-doped NiCoCe catalyst, including the following steps:

[0008] (1) Dissolve nickel nitrate, cobalt nitrate, cerium nitrate, aluminum nitrate and an alkaline precipitant in deionized water to prepare a mixed homogeneous solution, and fully stir the solution at room temperature to obtain solution A;

[0009] (2) Put solution A into a reaction kettle, and crystallize the mother liquor at a constant temperature for a certain time to obtain a solid-liquid mixture B;

[0010] (3) Centrifuge and wash the solid-liquid mixture B obtained in step (2) to remove excess precipitant to obtain precipitate C;

[0011] (4) Dry the precipitate C obtained in step (3) to obtain layered hydrotalcite precursor D;

[0012] (5) Put the precursor D obtained in step (4) into a H2 atmosphere to perform reduction passivation to obtain the Al-doped NiCoCe catalyst.

[0013] The content of oxygen vacancies in the CO2 methanation catalyst prepared by the traditional hydrothermal method is less. Considering the influence of the content of oxygen vacancies on the methanation reaction, the Al element is doped in the NiCoCe catalyst in the present application, the metal dispersion on the catalyst surface is changed, the metal-support interaction is enhanced, the number of surface basic sites is increased, the lattice oxygen is activated and migrated to the crystal surface, the number of oxygen vacancies on the catalyst surface is increased, and the CO2 adsorption capacity of the catalyst surface is improved. At the same time, the precursor is directly reduced without calcination to prepare the reduced catalyst, and the degree of reduction of Co 0 species in the catalyst is improved, so that the hydrogenation capacity of the catalyst is obviously improved. By adjusting the proportion of Al to change the CO2 adsorption capacity and hydrogenation capacity of the catalyst, the present application makes the two consistent, so that the high CO2 conversion rate of the CO2 methanation reaction at low temperature is realized. In addition, no Na ion is introduced by selecting urea as the precipitant, so that the influence of alkali metal on the experimental results is avoided, and the urea aqueous solution is weakly basic, which slowly hydrolyzes at the crystallization temperature to provide OH - and CO3 2- required for precipitation, which is beneficial to the formation of the precursor structure of hydrotalcite.

[0014] Further, in step (1), the molar ratio of the nickel nitrate, cobalt nitrate, cerium nitrate and aluminum nitrate is Ni+Co:Ce+Al=2:1, the proportion of Al is adjusted on the basis of not changing this ratio, the molar ratio Al:Al+Ce=0.05-0.95, and an appropriate amount of deionized water is added to make the solution concentration 0.1-0.2 mol / L.

[0015] Further, in step (1), the alkaline precipitant is 1.0-2.0 mol / L of urea.

[0016] Furthermore, in step (1), the stirring time is 1 to 1.5 hours.

[0017] Furthermore, in step (2), the crystallization temperature is 100-120℃ and the crystallization time is 10-12h.

[0018] Furthermore, in step (3), deionized water is used for washing, and the washing is repeated 6 to 8 times until the pH value of the solution is 7 to 8.

[0019] Furthermore, in step (4), the drying temperature is 80-100℃ and the drying time is 10-18h.

[0020] Furthermore, in step (5), during reduction, the reducing atmosphere is 10%–99.9% H2 (40 mL / min), the reduction temperature is 500–600 °C, the heating rate is 2–3 °C / min, the reduction time is 1–3 h, the passivation atmosphere is 1%–20% O2 / N2 (40 mL / min), and the passivation time is 4–6 h.

[0021] The present invention also provides an aluminum-doped NiCoCe catalyst prepared by the above preparation method, wherein the catalyst is composed of a bimetallic active component and a dual support, wherein the active component is Ni and Co, and the support is aluminum oxide and cerium oxide.

[0022] The present invention also provides the application of the aluminum-doped NiCoCe catalyst prepared above in the low-temperature CO2 hydrogenation to methane reaction.

[0023] The present invention has the following beneficial effects:

[0024] 1. The aluminum-doped NiCoCe catalyst prepared by this invention effectively solves the problem of low CO2 conversion rate in low-temperature CO2 methanation reaction; the introduction of Al element leads to the activation of lattice oxygen and migration to the crystal surface, increasing the number of oxygen vacancies on the catalyst surface and improving the CO2 adsorption capacity of the catalyst surface.

[0025] 2. This invention simplifies the preparation process and increases the Co content in the catalyst by directly reducing the precursor. 0 The degree of species reduction significantly enhances the catalyst's hydrogenation capacity;

[0026] 3. In this invention, urea is added as a precipitant. The urea aqueous solution is weakly alkaline, and slow hydrolysis at the crystallization temperature provides the OH- required for precipitation. - and CO3 2- This is conducive to the formation of precursor structures for hydrotalcite structures;

[0027] 4. The aluminum-doped NiCoCe catalyst prepared by this invention uses green, non-precious metals as raw materials, which are low in cost, simple in process, and suitable for industrial production. The catalyst of this invention is suitable for reaction at low temperature, which reduces reaction energy consumption and has stable chemical properties, which is conducive to large-scale application. Detailed Implementation

[0029] This invention provides a method for preparing an aluminum-doped NiCoCe catalyst, comprising the following steps:

[0030] (1) Dissolve nickel nitrate, cobalt nitrate, cerium nitrate, aluminum nitrate and alkaline precipitant in deionized water to prepare a mixed homogeneous solution, and stir the solution thoroughly at room temperature to obtain solution A;

[0031] (2) Place solution A into a stainless steel reactor lined with polytetrafluoroethylene and allow it to liquidate at a constant temperature for a certain period of time to obtain a solid-liquid mixture B.

[0032] (3) Centrifuge and wash the solid-liquid mixture B obtained in step (2) to remove excess precipitant and obtain precipitate C;

[0033] (4) The precipitate C obtained in step (3) is dried to obtain layered hydrotalcite precursor D;

[0034] (5) The precursor D obtained in step (4) is placed in H2 atmosphere for reduction passivation to obtain catalyst E.

[0035] Traditional hydrothermal methods produce CO2 methanation catalysts with low oxygen vacancy content. Considering the impact of oxygen vacancy content on the methanation reaction, this invention dops NiCoCe catalyst with Al, altering the metal dispersion on the catalyst surface, enhancing metal-support interactions, and increasing the number of surface basic sites. Simultaneously, lattice oxygen is activated and migrates to the crystal surface, further increasing the number of oxygen vacancies on the catalyst surface and improving CO2 adsorption capacity. Furthermore, the precursor is directly reduced without calcination to prepare the reduced catalyst, enhancing the reduction of Co to Co in the catalyst. 0 The degree of species concentration significantly enhances the catalyst's hydrogenation capacity. This invention modifies the catalyst's CO2 adsorption and hydrogenation capacity by adjusting the Al ratio, thereby converging the two to achieve a high CO2 conversion rate in the CO2 methanation reaction at low temperatures.

[0036] Metallic Al was introduced into the NiCoAl catalyst to form a layered double hydroxide (LDH) precursor, which was then calcined and reduced to obtain a supported catalyst. This catalyst meets the conventional M... 1-x 2+ and M x 3+The hydrotalcite structure formed by the metal combination provides LDH precursors with a high specific surface area and good metal ion dispersion, promoting CO2 adsorption. Supported catalysts prepared by the reduction method are less prone to agglomeration and sintering, exhibiting high catalytic activity and stable catalytic performance. Furthermore, due to the diversity of layered metal ions and interlayer anions, LDHs possess advantages such as tunable basicity and ease of modification; selective catalysis of specific reactions can be achieved by adjusting the types and ratios of ions. Therefore, adjusting the Al ratio during catalyst preparation is beneficial for better formation of the hydrotalcite structure, thereby improving catalytic activity.

[0037] Compared with CO2 methanation catalysts prepared by traditional hydrothermal methods, the catalyst prepared in this invention has more basic sites and oxygen vacancies, which can improve CO2 conversion rate and catalytic stability.

[0038] The present invention will be further illustrated below through specific embodiments.

[0039] Example 1

[0040] The preparation method of the aluminum-doped NiCoCe catalyst in this example specifically includes the following steps:

[0041] (1) Preparation of mixed solution A: Weigh 2.90g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O), 2.91g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 4.12g of cerium nitrate hexahydrate (Ce(NO3)3·6H2O), 0.18g of aluminum nitrate nonahydrate (Al(NO3)3·9H2O), and 12.012g of urea, dissolve them in 200mL of deionized water, stir at 800r / min for 1h, and obtain solid-liquid mixture A;

[0042] (2) Place the solid-liquid mixture A obtained in step (1) into a stainless steel reactor lined with polytetrafluoroethylene and liquidify the mother liquid at 120°C for 12 hours to obtain solid-liquid mixture B.

[0043] (3) Wash the solid-liquid mixture B obtained in step (2) with deionized water 6 to 8 times to remove excess precipitant until the pH of the solution is 7 to 8, and obtain precipitate C.

[0044] (4) Place the precipitate E obtained in step (3) in an oven and dry it at 80°C for 10 hours to obtain the layered hydrotalcite precursor NiCoCeAl. 0.05 -LDH;

[0045] (5) The precursor NiCoAlCe obtained in step (4) 0.05-LDH was placed in a tube furnace and reduced at 600°C for 3 hours under a 99.9% H2 atmosphere, followed by passivation under a 1% O2 / N2 atmosphere to obtain the catalyst NiCoCeAl. 0.05 .

[0046] Example 2

[0047] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 3.90 g of Ce(NO3)3·6H2O and 0.37 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.1 .

[0048] Example 3

[0049] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 3.03 g of Ce(NO3)3·6H2O and 1.12 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.3 .

[0050] Example 4

[0051] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 2.17 g of Ce(NO3)3·6H2O and 1.87 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.5 .

[0052] Example 5

[0053] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 1.30 g of Ce(NO3)3·6H2O and 2.62 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.7 .

[0054] Example 6

[0055] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 0.43 g of Ce(NO3)3·6H2O and 3.37 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.9 .

[0056] Example 7

[0057] The preparation method of the aluminum-doped NiCoCe catalyst in this embodiment is basically the same as that in Example 1, except that 0.21 g of Ce(NO3)3·6H2O and 3.56 g of Al(NO3)3·9H2O are added in step (1). Accordingly, the catalyst prepared in this example by doping metallic aluminum to increase oxygen vacancies and improve the low-temperature CO2 methanation performance is labeled as NiCoCeAl. 0.95 .

[0058] Comparative Example 1

[0059] The NiCoCe catalyst preparation method in this example specifically includes the following steps:

[0060] (1) Preparation of mixed solution A: Weigh 2.90g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O), 2.91g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 4.34g of cerium nitrate hexahydrate (Ce(NO3)3·6H2O), and 12.012g of urea, dissolve them in 200mL of deionized water, stir at 800r / min for 1h, and obtain solid-liquid mixture A;

[0061] (2) Place the solid-liquid mixture A obtained in step (1) into a stainless steel reactor lined with polytetrafluoroethylene and liquidify the mother liquid at 120°C for 12 hours to obtain solid-liquid mixture B.

[0062] (3) Wash the solid-liquid mixture B obtained in step (2) with deionized water 6 to 8 times to remove excess precipitant until the pH of the solution is 7 to 8, and obtain precipitate C.

[0063] (4) Place the precipitate E obtained in step (3) in an oven and dry it at 80°C for 10 hours to obtain the layered hydrotalcite precursor NiCoCe-LDH;

[0064] (5) The precursor NiCoAlCe obtained in step (4) 0.05 -LDH was placed in a tube furnace and reduced at 600°C for 3 hours under a 99.9% H2 atmosphere, followed by passivation under a 1% O2 / N2 atmosphere to obtain the catalyst NiCoCe.

[0065] Comparative Example 2

[0066] The NiCoAl catalyst preparation method in this example specifically includes the following steps:

[0067] (1) Preparation of mixed solution A: Weigh 2.90g of nickel nitrate hexahydrate (Ni(NO3)2·6H2O), 2.91g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 3.75g of aluminum nitrate nonahydrate (Al(NO3)3·9H2O), and 12.012g of urea, dissolve them in 200mL of deionized water, stir at 800r / min for 1h, and obtain solid-liquid mixture A;

[0068] (2) Place the solid-liquid mixture A obtained in step (1) into a stainless steel reactor lined with polytetrafluoroethylene and liquidify the mother liquid at 120°C for 12 hours to obtain solid-liquid mixture B.

[0069] (3) Wash the solid-liquid mixture B obtained in step (2) with deionized water 6 to 8 times to remove excess precipitant until the pH of the solution is 7 to 8, and obtain precipitate C.

[0070] (4) Place the precipitate E obtained in step (3) in an oven and dry it at 80°C for 10 hours to obtain the layered hydrotalcite precursor NiCoAl-LDH;

[0071] (5) The precursor NiCoAlCe obtained in step (4) 0.05 -LDH was placed in a tube furnace and reduced at 600°C for 3 hours under a 99.9% H2 atmosphere, followed by passivation under a 1% O2 / N2 atmosphere to obtain the catalyst NiCoAl.

[0072] The catalysts prepared in Examples 1-7 and Comparative Examples 1-2 were subjected to catalyst performance testing and characterization:

[0073] When evaluating the performance of the catalyst, in order to ensure that the catalyst particles are uniform in size and do not clog the reaction tube, the catalysts prepared in Examples 1 to 7 and Comparative Examples 1 to 2 of the present invention should all be made into catalyst particles of 40 to 60 mesh.

[0074] The catalysts prepared in Examples 1-7 and Comparative Examples 1-2 were evaluated in a micro-stationary reactor. The process conditions were: 0.5-1 g of 40-60 mesh catalyst, reaction temperature 150-300℃, reaction pressure 0.1-2 MPa, feed gas H2 / CO2 = 4, and space velocity 10000-20000 mL·h. -1 ·g -1 .

[0075] For example, the NiCoCeAl prepared in Example 6 was tested in a fixed-bed reactor. 0.9 The catalyst performance was evaluated using the following steps: 0.5g of catalyst was weighed and placed in the isothermal zone of the reaction tube. The feed gas ratio (H2 / CO2) was 4, the temperature was 150–300℃, the pressure was 1 MPa, and the space velocity (GHSV) was 20000 mL·h. -1 ·g -1 After reaching a stable state, samples were taken for analysis at 1-hour intervals. Gas chromatography was used to perform quantitative and qualitative analysis of the feed gas and products. Using the methane correlation method described in "Determination of H2, N2, CO, CO2 and C1-C8 Hydrocarbons in Coal-Based Fischer-Tropsch Synthesis Tail Gas and Gas Chromatography," the CO2 conversion rate and CH4 selectivity were calculated. Specific results are shown in Table 1.

[0076] Table 1. Catalysts prepared in Examples 1-7 and Comparative Examples 1-2 under conditions of 1 MPa, 200 °C, and 20000 mL·h -1 ·g -1 Catalytic activity experimental data

[0077]

[0078] Table 2 shows the catalyst prepared in Example 6 at 1 MPa and 20000 mL·h. -1 ·g -1 Reaction performance at different temperatures

[0079]

[0080] Table 1 shows that the catalyst is effective at 1 MPa, 200 °C, and 20000 mL·h. -1 ·g -1 The catalytic activity experimental data showed that the CH4 selectivity of all catalysts was close to 99.8%–99.9%, indicating that changing the amount of Al doping did not affect the methanation selectivity, but the CO2 conversion rate showed significant differences. Compared with NiCoCe catalysts prepared by the traditional hydrothermal method, the series of catalysts prepared by introducing Al showed more significant catalytic performance. Among them, Example 6 (NiCoCeAl) 0.9 The catalyst exhibited the highest CO2 conversion rate (86.2%), indicating that the Al ratio was optimally adjusted to ensure that the CO2 adsorption capacity and H2 dissociation capacity were nearly identical, thus achieving a high CO2 conversion rate at a low temperature (200℃). This is attributed to the NiCoCeAl content. 0.9 The catalyst exhibits higher metal dispersion and stronger metal-support interaction, resulting in a greater number of surface basic sites and oxygen vacancies, thus enhancing its CO2 adsorption capacity. Furthermore, in NiCoCeAl... 0.9 Co in catalyst 0 A higher proportion enhances hydrogenation capacity.

[0081] As can be seen from Table 2, Example 6 (NiCoCeAl) 0.9 The conversion rate of the catalyst at 1 MPa and 20000 mL·h⁻¹·g⁻¹ rapidly increased from 6.1% to 86.2% in the low-temperature range (150–200 °C), indicating that increasing temperature promoted the reaction. This is because the kinetics of the CO₂ methanation catalyst are slow at low temperatures, and increasing temperature accelerates the reaction. In the medium-high temperature range (200–300 °C), the conversion rate stabilized at around 87.3% and no longer increased significantly. This indicates that a high CO₂ conversion rate can be achieved at around 200 °C, without the need for higher temperatures, demonstrating the advantages of low-temperature methanation. Furthermore, as the temperature increased from 150 °C to 200 °C and above, the CH₄ selectivity increased from 98.4% to 99.9% and remained stable. This shows that increasing temperature not only accelerates the reaction but also further suppresses side reactions, achieving optimal methane selectivity. Therefore, by adjusting the CO2 adsorption capacity with Al doping, enhancing the hydrogenation capacity through direct reduction of the precursor, and optimizing the Al ratio to match the two, a high conversion rate and high selectivity of CO2 methanation at low temperature (around 200℃) were finally achieved.

[0082] The catalyst prepared by this invention, which increases oxygen vacancies to improve the performance of low-temperature CO2 methanation, effectively solves the problem of low CO2 conversion rate in low-temperature CO2 methanation reaction. By introducing Al, the crystal lattice is distorted, increasing the migration ability of lattice oxygen. The formation of a large number of oxygen vacancies is beneficial to improving the redox properties of the catalyst.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an aluminum-doped NiCoCe catalyst, characterized in that, Includes the following steps: (1) Dissolve nickel nitrate, cobalt nitrate, cerium nitrate, aluminum nitrate and alkaline precipitant in deionized water to prepare a mixed homogeneous solution, and stir the solution thoroughly at room temperature to obtain solution A; (2) Place solution A into a reaction vessel and allow it to liquidate at a constant temperature for a certain period of time to obtain a solid-liquid mixture B. (3) Centrifuge and wash the solid-liquid mixture B obtained in step (2) to remove excess precipitant and obtain precipitate C; (4) The precipitate C obtained in step (3) is dried to obtain layered hydrotalcite precursor D; (5) The precursor D obtained in step (4) is placed in an H2 atmosphere for reduction passivation to obtain the aluminum-doped NiCoCe catalyst.

2. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (1), the molar ratio of nickel nitrate, cobalt nitrate, cerium nitrate, and aluminum nitrate is Ni+Co:Ce+Al=2:

1. Without changing this ratio, the proportion of Al is adjusted to a molar ratio of Al:Al+Ce=0.05~0.95, and an appropriate amount of deionized water is added to make the solution concentration 0.1~0.2mol / L.

3. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (1), the alkaline precipitant is urea at a concentration of 1.0 to 2.0 mol / L.

4. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (1), the stirring time is 1 to 1.5 hours.

5. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (2), the crystallization temperature is 100-120℃ and the crystallization time is 10-12h.

6. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (3), deionized water is used for washing, and the washing is repeated 6 to 8 times until the pH value of the solution is 7 to 8.

7. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (4), the drying temperature is 80-100℃ and the drying time is 10-18h.

8. The method for preparing the aluminum-doped NiCoCe catalyst as described in claim 1, characterized in that: In step (5), during reduction, the reducing atmosphere is 10%–99.9% H2 (40 mL / min), the reduction temperature is 500–600℃, the heating rate is 2–3℃ / min, the reduction time is 1–3 h, the passivation atmosphere is 1%–20% O2 / N2 (40 mL / min), and the passivation time is 4–6 h.

9. The aluminum-doped NiCoCe catalyst prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The catalyst consists of a bimetallic active component and a dual support, wherein the active component is Ni and Co, and the support is alumina and cerium oxide.

10. The application of the aluminum-doped NiCoCe catalyst according to claim 9 in the low-temperature CO2 hydrogenation to methane reaction.

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