A multi-metal doped ceria catalyst, a preparation method and application thereof

Abstract

This invention belongs to the field of catalyst technology, specifically relating to a multi-metal-doped cerium oxide catalyst and its preparation and application. The catalyst comprises a γ-Al₂O₃ support and an active component supported thereon, wherein the chemical formula of the active component is Ni. a Fe b Ru c Co d Ce1 a b c d O 2‑δ Wherein, 0.05≤a≤0.1, 0.04≤b≤0.06, 0.04≤c≤0.06, 0≤d≤0.06, and a+b+c+d≤0.2. The catalyst is prepared by solution impregnation, by preparing a metal salt solution and impregnating it on a γ-Al2O3 support to obtain a sol with a complexing agent, which is then aged, dried, and calcined in stages. The catalyst is used in the steam reforming reaction of aviation kerosene (n-dodecane simulation), and can achieve 100% catalytic conversion at 700 °C, without deactivation after 100 h of continuous operation, exhibiting low-temperature activity and anti-carbon deposition performance; wherein Ni 0.05 Fe 0.05 Ru 0.05 Co 0.05 Ce 0.8 O 2‑δ When reformed gas drives a tubular solid oxide fuel cell, the power density reaches 830.90 mW / cm³. 2 It operates stably for 100 hours without significant degradation. The process of this invention is simple and cost-controllable, and it is applicable to the fields of hydrogen production from aviation kerosene reforming and SOFC coupled power generation.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a multi-metal doped cerium oxide catalyst, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Solid oxide fuel cells (SOFCs), as efficient and clean energy conversion devices, can directly convert the chemical energy of fuel into electrical energy. They possess advantages such as strong fuel adaptability, high energy conversion efficiency, and an all-solid-state structure, showing broad application prospects in distributed power generation and portable power supplies. Aviation kerosene, as a typical high-energy-density liquid hydrocarbon fuel, exhibits unique research value and application potential in the field of SOFC fuel supply due to its high volumetric energy density of 42-46 MJ / kg, ease of transportation and storage, and utilization of existing fuel infrastructure. However, aviation kerosene is a complex mixture composed of C8-C16 long-chain alkanes, cycloalkanes, and aromatics, and its reforming for hydrogen production faces a series of severe challenges. First, the breaking of C-C bonds in long-chain hydrocarbons requires higher activation energies, and reforming reactions typically need to be carried out at high temperatures of 700-900 °C. Second, heavy hydrocarbons are prone to cracking and carbon deposition on the surface of traditional Ni-based catalysts, and trace amounts of sulfides in fuels can also poison Ni catalysts. In addition, the high olefin content in long-chain hydrocarbon reforming products further exacerbates the risk of carbon deposition. Carbon deposition not only covers active sites but may also damage the catalyst structure through physical stress, leading to irreversible performance loss.

[0004] Currently, research on aviation kerosene reforming catalysts mainly focuses on Ni-based and noble metal (such as Pt and Ru) supported catalysts. Noble metal catalysts (such as Pt and Ru) exhibit high activity and stability in aviation kerosene reforming due to their excellent C / C bond breaking ability and superior resistance to carbon deposition; however, their high cost limits their large-scale application. Ni-based catalysts, due to their low cost and high C / C bond breaking activity, have become the most widely used non-noble metal catalysts in aviation kerosene reforming research. However, traditional Ni-based catalysts face two major challenges: the easy sintering and agglomeration of active Ni nanoparticles and their susceptibility to deactivation due to carbon deposition.

[0005] In the existing technology, there have been studies on using single or binary metals doped into cerium-based oxides for hydrocarbon reforming. However, there are still the following defects in the dedicated catalysts for aviation kerosene steam reforming: (1) Single / bimetallic doped catalysts, such as Ni-CeO2, although they have certain activity, Ni-based catalysts are prone to forming encapsulated carbon deposits, leading to rapid deactivation; while Ru-based catalysts are expensive and have limited hydrogen selectivity improvement; (2) Traditional composite oxide catalysts, such as Co-CaO-Al2O3 or Rh / CeO2-ZrO2, usually require a high reaction temperature (≥750 ℃) to achieve complete conversion of diesel, and some catalysts have poor thermal stability and metal particles are prone to sintering; (3) Existing multi-metal doped catalysts fail to give full play to the synergistic effect between multiple metals due to unreasonable metal ratios, resulting in insufficient oxygen vacancy concentration, weak ring-opening cracking ability of aromatic hydrocarbons in diesel, and significant decay of catalytic conversion rate after long-term operation. Therefore, developing a catalyst that can achieve efficient and stable conversion of aviation kerosene at lower temperatures and is well matched with the SOFC anode, and revealing its anti-carbon deposition mechanism, is of great significance for promoting the practical application of aviation kerosene in tubular SOFCs. Summary of the Invention

[0006] This invention addresses the problems of existing aviation kerosene steam reforming catalysts, such as high complete conversion temperature, weak resistance to carbon deposition, poor long-term catalytic stability, and poor coupling performance with SOFC, by providing a multi-metal doped cerium oxide catalyst, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a multi-metal-doped cerium oxide catalyst, comprising a porous γ-Al₂O₃ support and an active component supported thereon; the active component is doped by substituting a metal element for Ce sites in the CeO₂ lattice, and its general chemical formula is Ni. a Fe b Ru c Co d Ce (1 a b c d) O 2-δ a, b, c, and d are mole fractions that satisfy 0.05 ≤ a ≤ 0.1, 0.04 ≤ b ≤ 0.06, 0.04 ≤ c ≤ 0.06, 0 ≤ d ≤ 0.06, and a + b + c + d ≤ 0.2.

[0008] Furthermore, δ in the chemical formula represents the non-stoichiometric ratio of oxygen, and its value ranges from 0 to 0.5. The specific value depends on the metal doping ratio and preparation conditions. The presence of δ indicates that there are oxygen vacancies in the material lattice.

[0009] This invention introduces multiple metals such as Ni, Fe, Ru, and Co, utilizing their synergistic effects to enhance the oxygen vacancy concentration, metal dispersion, and anti-carbon deposition capabilities of the catalyst, thereby achieving complete catalytic conversion of aviation kerosene at low temperatures. Simultaneously, the use of γ-Al₂O₃ as a support significantly improves the dispersion of the active components and the mechanical strength of the catalyst.

[0010] Furthermore, when the catalyst is a ternary doped catalyst, the chemical formula of its active component is preferably Ni. 0.1 Fe 0.05 Ru 0.05 Ce 0.8 O 2-δ .

[0011] Furthermore, when the catalyst is a quaternary doped catalyst, the chemical formula of its active component is preferably Ni. 0.05 Fe 0.05 Ru 0.05 Co 0.05 Ce 0.8 O 2-δ .

[0012] This invention also provides a method for preparing the above-mentioned multi-metal doped cerium oxide catalyst, the method comprising the following steps: (1) Weigh out nickel source, iron source, ruthenium source, cobalt source and cerium source as metal precursors according to the molar ratio of the chemical formula of the active components, add complexing agent, dissolve in ethanol aqueous solution to form metal salt solution; (2) Immerse the porous γ-Al2O3 support in the metal salt solution and use vacuum to assist the impregnation so that the solution can fully penetrate into the pores of the support; take out the impregnated support and dry it to remove residual moisture on the surface; repeat once or multiple times to increase the loading of active components. (3) The sample dried in step (2) is sintered in an oxygen-containing atmosphere to obtain the multi-metal doped cerium oxide catalyst.

[0013] Furthermore, in step (1), the nickel source is nickel nitrate, the iron source is ferric nitrate, the ruthenium source is ruthenium trichloride, the cobalt source is cobalt nitrate, and the cerium source is cerium nitrate; the raw materials need to be added in the order of cerium source, nickel source, iron source, ruthenium source, and cobalt source, and the next raw material is added after one raw material has been completely dissolved.

[0014] Furthermore, the ethanol in the impregnation solution has a volume fraction of 10-30%, which is used to reduce surface tension and promote the penetration of the impregnation solution into the micropores of the carrier.

[0015] Furthermore, the vacuum filtration time in step (2) is 20 min; the drying temperature is 80~120 ℃ and the time is 4~12 h.

[0016] Furthermore, the sintering process in step (3) involves heating to 600~800 ℃ at a heating rate of 2 ℃ / min and calcining for 1~3 h.

[0017] Furthermore, after sintering in step (3), the active component loading of the catalyst is approximately 5 wt.%.

[0018] Ce, as a catalyst support, provides lattice oxygen and oxygen vacancies, oxidizing and removing carbon species generated in the reaction and inhibiting coking; at the same time, it stabilizes metal nanoparticles through strong metal-support interactions, preventing sintering; Ni, the main active metal, has excellent C / C bond cleaving ability, improving aviation kerosene conversion efficiency and hydrogen selectivity; Fe regulates the redox performance of the catalyst, increases oxygen vacancy concentration, enhances the activation ability of steam, and assists in the cracking of aromatic hydrocarbons; Ru, a noble metal promoter, significantly improves the catalyst's resistance to coking, inhibits the formation of encapsulated coking deposits, and lowers the complete conversion temperature of aviation kerosene; Co synergistically improves metal dispersibility, enhances the thermal stability of the catalyst, and further improves hydrogen selectivity and long-term operational stability.

[0019] The reforming reaction was carried out under the following conditions: reduction at 650–750 °C for 3–6 h in a hydrogen atmosphere; a vapor-to-carbon ratio (S / C) of 3.0–3.5; and a space velocity (GHSV) of 3000–3500 h⁻¹. -1 .

[0020] This invention also provides a multi-metal doped cerium oxide catalyst for use in aviation kerosene steam at atmospheric pressure; reformed gas is directly introduced into a tubular SOFC stack to achieve reforming-power generation coupling, with the SOFC operating temperature at 650~750 ℃.

[0021] Furthermore, the application also includes using reformed gas generated from the reforming reaction of aviation kerosene steam to drive solid oxide fuel cells.

[0022] The beneficial effects of the technical solution provided by this invention are: (1) The two catalysts provided by this invention can achieve 100% conversion of aviation kerosene at a low temperature of 700 °C. Compared with the high temperature of 750-800 °C required by traditional catalysts (such as Rh / CeO2-ZrO2, Ni / Al2O3), the reaction temperature is reduced by 50-100 °C, which significantly reduces energy consumption and is more suitable for the operation requirements of medium-temperature SOFC.

[0023] (2) Through the synergistic effect of multiple metals such as Ni, Fe, Ru and Co, the catalyst surface has a high oxygen vacancy concentration, which can effectively oxidize and remove carbon species generated in the reaction. After running continuously at 700 °C for 100 h, the catalyst can still maintain 100% conversion rate, without activity decay and obvious carbon deposition. Its long-term stability is significantly better than that of the NFCO catalyst in Comparative Example 1.

[0024] (3) The catalyst prepared by the solution impregnation method of this invention is a nano-sized powder with small and uniformly distributed active metal particles. After sintering, there is no obvious particle growth, which shows excellent thermal stability and can adapt to temperature fluctuations in the SOFC coupling process.

[0025] (4) When the aviation kerosene reformed gas generated by the catalyst of this invention drives a tubular SOFC, the maximum power density of the SOFC corresponding to the ternary doped catalyst reaches 778.57 mW / cm³. 2 The quaternary doped catalyst reached 830.90 mW / cm². 2 Compared to the previous performance, it improved by 11%-19%, and showed no significant degradation after 100 hours of stable operation. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the test device for coupling liquid fuel vapor reforming and solid oxide fuel cell of the present invention; Figure 2 Figure 1 shows the nitrogen adsorption-desorption isotherms and pore size distributions of different catalysts and γ-Al2O3 prepared in Examples 1, 2, and Comparative Example 1; Figure (a) is the nitrogen adsorption-desorption isotherm; and (b) is the corresponding pore size distribution curve. Figure 3 The XRD patterns of the catalysts prepared in Examples 1, 2 and Comparative Example 1 are shown; Figure (a) shows the catalysts before hydrogen reduction and Figure (b) shows the catalysts after hydrogen reduction. Figure 4 The performance of the catalyst in aviation kerosene steam reforming at an S / C ratio of 3 is shown in the graph; (a) is the conversion rate; (b) is the product concentration; (c) is the selectivity of H2 and CO; (d) is the c(H2) / c(CO). Figure 5 Long-term stability tests of the catalysts prepared for Example 1, Example 2 and Comparative Example 1 on aviation kerosene steam reforming at 700 °C; (a) conversion rate; (b) product concentration; (c) CO selectivity; Figure 6 The XRD and SEM images of the catalysts prepared in Examples 1, 2 and Comparative Example 1 after being treated with aviation kerosene steam atmosphere for 5 h are shown. Figure 7 The current-voltage curves of a tubular fuel cell under an aviation kerosene steam reforming atmosphere are shown. Detailed Implementation

[0027] The specific embodiments of the present invention are described in detail below. These embodiments are intended to more fully demonstrate the technical content of the present invention and help to understand the specific implementation process of the present invention, but their content should not be construed as limiting the scope of the claims of the present invention in any way. For those skilled in the art, various adjustments, modifications, and substitutions made to the embodiments without departing from the spirit and scope of the present invention are all within the scope of protection sought by the present invention.

[0028] Example 1 Ni 0.1 Fe 0.05 Ru 0.05 Ce 0.8 O 2-δ Preparation of @γ-Al2O3 (NFRCO@γ-Al2O3) catalyst.

[0029] Nickel acetate, ferric nitrate, ruthenium chloride, and cerium nitrate were weighed according to the molar ratio of Ni:Fe:Ru:Ce = 0.1:0.05:0.05:0.8, dissolved in deionized water, and glycine (molar ratio to total metal ions 1.5:1) was added. 20 vol.% ethanol was also added to prepare a 0.3 mol / L metal salt solution. Porous γ-Al₂O₃ spheres were immersed in the above solution, and a vacuum of 1 MPa was applied for 20 min. The sample was then removed and dried at 90 °C for 10 h. The above immersion-drying process was repeated once.

[0030] Sintering: The dried sample was sintered at 800 °C for 2 h to obtain an NFRCO@γ-Al2O3 catalyst with an active component loading of about 5 wt.%.

[0031] Reduction: Before use, the catalyst was reduced in a hydrogen atmosphere at 750 °C for 5 h to obtain the active catalyst NFRCO@γ-Al2O3, which was used for the final hydrocarbon fuel steam reforming reaction.

[0032] Example 2 Ni 0.05 Fe 0.05 Ru 0.05 Co 0.05 Ce 0.8 O 2-δ Preparation of @γ-Al2O3 (NFRCCO@γ-Al2O3) catalyst.

[0033] Weigh out nickel acetate, ferric nitrate, ruthenium chloride, cobalt nitrate, and cerium nitrate in a molar ratio of Ni:Fe:Ru:Co:Ce = 0.05:0.05:0.05:0.8, dissolve them in deionized water, add glycine (molar ratio to total metal ions 1.5:1), and add 25 vol.% ethanol to prepare a 0.3 mol / L metal salt solution. Impregnation: Immerse porous γ-Al₂O₃ spheres in the above solution, apply a vacuum of 1 MPa, and maintain for 20 min. Remove the sample and dry it at 90 °C for 8 h. Repeat the above impregnation-drying process once.

[0034] Sintering: The dried sample was sintered at 800 °C for 2 h to obtain an NFRCCO@γ-Al2O3 catalyst with an active component loading of approximately 5 wt.%.

[0035] Reduction: Before use, the catalyst is reduced in a hydrogen atmosphere at 750 °C for 5 h to obtain the active catalyst.

[0036] Comparative Example 1 Undoped Ru (Ni) 0.10 Fe 0.10 Ce 0.8 O 2-δ Preparation of γ-Al2O3 (NFCO@γ-Al2O3) catalyst.

[0037] Weigh nickel acetate, ferric nitrate, and cerium nitrate according to the molar ratio of Ni:Fe:Ce = 0.10:0.10:0.8, dissolve them in deionized water, add glycine (molar ratio to total metal ions 1.5:1), and add 20 vol.% ethanol to prepare a 0.3 mol / L metal salt solution. Impregnation: Immerse porous γ-Al₂O₃ spheres in the above solution, apply a vacuum of 1 MPa, and maintain for 20 min. Remove the sample and dry it at 90 ℃ for 8 h. Repeat the above impregnation-drying process once.

[0038] Sintering: The dried sample was sintered at 800 °C for 2 h to obtain an NFRCCO@γ-Al2O3 catalyst with an active component loading of approximately 5 wt.%.

[0039] Reduction: Before use, the catalyst was reduced in a hydrogen atmosphere at 750 °C for 5 h to obtain NFCO@γ-Al2O3 catalyst.

[0040] like Figure 2As shown, the isotherms of the catalysts prepared in Examples 1, 2, and Comparative Example 1 all belong to type IV isotherms, exhibiting a hysteresis loop at a relative pressure (P / P0) of 0.6-1, indicating that the samples exhibit a mesoporous structure. Comparison of the γ-Al₂O₃ samples before and after loading reveals that the isotherm curves and the position of the hysteresis loop do not change significantly, indicating that the active catalyst material can be uniformly deposited on the support surface without significantly altering the pore structure characteristics of the support.

[0041] Figure 3 In (a), NFCO exhibits a pure-phase fluorite structure with no impurity peaks, and trace amounts of RuO2 phase are detected on the NFRCO / NFRCCO matrix. Figure 3 As shown in (b), after sample reduction, Ni-Fe alloy is precipitated in NFCO; Ru metal nanoparticles are formed on the surface of NFRCO; Ni-Fe and Ru metal nanoparticles are precipitated in NFRCO. Through lattice doping and controllable precipitation, multi-metals form a dual active center structure in which Ni-Fe alloy and Ru nanoparticles coexist synergistically. This is the basis for the catalyst to have both low-temperature high activity and ultra-strong stability.

[0042] Figure 4 The results show that the NFCO catalyst exhibits excellent initial conversion efficiency for the steam reforming of aviation kerosene at 800℃. However, as the reaction temperature decreases, the activity of the catalyst decreases significantly, while the selectivity for H2 and CO decreases sharply, accompanied by an increase in CH4 and CO2 concentrations. This phenomenon can be attributed to the decrease in the efficiency of the methane reforming reaction at low temperatures and the enhanced thermodynamic advantages of the water-gas shift reaction. Compared with NFCO@γ-Al2O3, NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 catalysts show significantly enhanced catalytic performance in the steam reforming of aviation kerosene. They can maintain 100% complete conversion above 700℃, and even at 700℃, they maintain high activity, with aviation kerosene conversion efficiencies reaching 93.459% and 100%, respectively, while maintaining nearly 100% H2 selectivity and approximately 52% CO selectivity. As the temperature decreased to 650 °C, the conversion rate of NFRCO@γ-Al2O3 for aviation kerosene steam reforming was only 67.948%, but NFRCCO@γ-Al2O3 could still maintain a conversion rate of 89.448%, indicating that Co doping can improve the catalytic activity of the material to a certain extent.

[0043] like Figure 5As shown, the NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 catalysts exhibited excellent long-term operational stability at 700℃. During a continuous test period of up to 100 h, the aviation kerosene conversion rate of both catalysts remained close to 100% without significant degradation. Simultaneously, the concentrations of each component in the reformate remained stable, and the selectivity of H2 and CO did not decrease throughout the entire test period. These results demonstrate that the NFRCO and NFRCCO catalysts possess excellent resistance to deactivation at 700℃.

[0044] The excellent long-term stability of NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 catalysts can be attributed to several factors: First, the addition of Ru effectively promotes water activation, facilitates steam reforming, inhibits coke formation, and maintains the active sites of the catalyst. Second, Co doping enhances the low-temperature activity of the catalyst and improves the material's selective cleavage ability for C2C, enabling it to maintain efficient and stable catalytic performance even at 700 °C. Furthermore, the good thermal stability of the γ-Al2O3 support and the metal-support interaction help suppress the sintering and loss of active components. Among these, the synergistic effect of Co in the NFRCCO@γ-Al2O3 catalyst further enhances the overall stability of the catalytic system, laying the foundation for its practical application in aviation kerosene steam reforming.

[0045] like Figure 6 As shown, no obvious filamentous carbon deposits or carbon fiber structures were observed in the SEM images of the three catalysts after treatment with aviation kerosene steam atmosphere for 5 h. The catalyst particles had intact morphology, and the metal nanoparticles were uniformly dispersed on the support surface. Combined with the XRD analysis results, it can be seen that a large number of filamentous carbon (carbon fiber) structures appeared on the surface of the NFCO@γ-Al2O3 catalyst. These carbon filaments were densely interwoven and covered the catalyst surface, and in some areas, they even completely enveloped the active metal particles. Furthermore, the characteristic diffraction peak of nitrogen-containing carbon species (CNx) was detected at 2θ≈33° in its XRD spectrum, indicating that carbon species existed on its surface in the form of thin layers or nanocrystals. In contrast, no carbon deposition signals were detected in the SEM and XRD of the NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 catalysts, confirming that their surfaces were truly clean and free of carbon deposits. In summary, the NFCO@γ-Al2O3 catalyst deactivates rapidly due to filamentous carbon deposition, while the NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 catalysts maintain stable catalytic performance during long-term operation due to their excellent resistance to carbon deposition.

[0046] To evaluate the feasibility of aviation kerosene as a fuel cell fuel, reformed aviation kerosene gas, after being reformed by NFCO@γ-Al2O3, NFRCO@γ-Al2O3, and NFRCCO@γ-Al2O3 catalysts, was introduced into the anode of a tubular fuel cell, and its electrochemical performance in the temperature range of 750–600 °C was investigated. The results are as follows: Figure 7 As shown, when using NFRCO@γ-Al2O3 and NFRCCO@γ-Al2O3 reformed gas, the open-circuit voltage of the battery in the range of 750~600℃ is successively higher than that of NFCO@γ-Al2O3, indicating that the syngas fuel concentration is higher and the thermodynamic driving force is stronger. Within the range of 750~600℃, the peak power density of the battery consistently follows the pattern of NFRCCO@γ-Al2O3>NFRCO@γ-Al2O3>NFCO@γ-Al2O3, with NFRCCO@γ-Al2O3 showing an improvement of approximately 34% in the high-temperature region and approximately 11% in the low-temperature region compared to NFCO@γ-Al2O3. The NFRCCO@γ-Al2O3 catalyst can still maintain nearly 90% aviation kerosene conversion rate in the low-temperature region of 650℃, while the reforming activity and stability of NFCO@γ-Al2O3 are poor. The output performance of fuel cells is highly correlated with the activity of reforming catalysts. NFRCCO@γ-Al2O3, with its excellent low-temperature activity and anti-carbon deposition ability, provides high-quality syngas for the battery and shows potential for integrated applications.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-metal-doped cerium oxide catalyst, characterized in that, The catalyst comprises a porous γ-Al₂O₃ support and an active component supported thereon; the chemical formula of the active component is: Ni a Fe b Ru c Co d Ce1 a b c d O 2-δ a, b, c, and d represent the mole fractions of the corresponding metallic elements, satisfying: 0.05≤a≤0.1, 0.04≤b≤0.06, 0.04≤c≤0.06, 0≤d≤0.06, and a+b+c+d≤0.2; δ represents the oxygen vacancy content.

2. The multi-metal doped cerium oxide catalyst according to claim 1, characterized in that, The chemical formula of the active component is Ni. 0.1 Fe 0.05 Ru 0.05 Ce 0.8 O 2-δ or Ni 0.05 Fe 0.05 Ru 0.05 Co 0.05 Ce 0.8 O 2-δ .

3. A method for preparing a multi-metal-doped cerium oxide catalyst according to any one of claims 1 or 2, characterized in that, The following steps are adopted: (1) Weigh out nickel source, iron source, ruthenium source, cobalt source and cerium source according to stoichiometric ratio, add complexing agent, dissolve in aqueous ethanol solution to form metal salt solution; (2) Immerse the porous γ-Al2O3 support in the metal salt solution of step (1) using vacuum-assisted impregnation, remove and dry, and repeat the impregnation-drying process once; (3) The sample obtained in step (2) is sintered to obtain the multi-metal doped cerium oxide catalyst.

4. The preparation method according to claim 3, characterized in that, In step (1), the nickel source is nickel nitrate, the iron source is ferric nitrate, the ruthenium source is ruthenium trichloride, the cobalt source is cobalt nitrate, and the cerium source is cerium nitrate; the complexing agent is glycine; and the molar ratio of glycine to total metal ions is 1.5:

1.

5. The preparation method according to claim 3, characterized in that, In step (1), the volume fraction of ethanol in the impregnation solution is 10-30%; the concentration of the metal salt solution is 0.2-0.5 mol / L.

6. The preparation method according to claim 3, characterized in that, The drying temperature in step (2) is 80-120℃ and the time is 4-12 h.

7. The method according to claim 4, characterized in that, In step (3), the sintering process involves heating to 600~800 ℃ at a heating rate of 2 ℃ / min and calcining for 1~3 h.

8. The application of a catalyst as described in any one of claims 1 and 2 or a catalyst prepared by any one of claims 3-7 in an aviation kerosene steam reforming reaction.

9. The application according to claim 8, characterized in that, The conditions for the aviation kerosene steam reforming reaction are as follows: reduction at 650-750 °C for 3-6 h in a hydrogen atmosphere, a water-to-carbon ratio of 3.0-3.5, and a gas hourly space velocity of 3000-3500 (mL·h). -1 ) / mL.

10. The application according to claim 8 or 9, characterized in that, The reformed gas generated by the aviation kerosene steam reforming reaction is used to drive the solid oxide fuel cell.

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