Process for the preparation of a trans-cerium dioxide-nickel catalyst and use thereof

Abstract

The application belongs to the technical field of metal catalysts, and particularly relates to a preparation method and application of a trans-cerium dioxide-nickel catalyst. Nickel nitrate, polyvinylpyrrolidone, ethylene glycol, urea and water are mixed to perform a hydrothermal reaction, and then are separated to obtain a reaction product; the reaction product is washed, dried, calcined and cooled to obtain a catalyst precursor; water is added to the catalyst precursor for dispersion to obtain a turbid liquid, cerium nitrate is added to the turbid liquid for dissolution and heating to obtain a solid product; the solid product is calcined and cooled, and then subjected to a reduction reaction to obtain the trans-cerium dioxide-nickel catalyst. The trans-cerium dioxide-nickel catalyst in the application takes CeO2 as a metal active site and takes Ni as a catalyst carrier, and overcomes the problems of reduction of oxygen vacancies and recession of oxygen storage / release capacity of traditional large-size CeO2 due to grain growth and structure tending to perfect stability at high temperatures, and the trans-cerium dioxide-nickel catalyst has excellent catalytic effect with a small amount of Ce, and has important significance for utilization of rare earth resources.

Description

Technical Field

[0001] This invention belongs to the field of metal catalyst technology, specifically relating to a method for preparing and applying a trans-cerium dioxide-nickel catalyst. Background Technology

[0002] The core of the methane-carbon dioxide dry reforming reaction is to convert methane and carbon dioxide, two greenhouse gases, into syngas (H2+CO) under the action of a high-temperature catalyst. This reaction has the dual value of "emission reduction" and "resource production," and is one of the key technologies for addressing the energy crisis and the greenhouse effect. The core background demand for the methane-carbon dioxide dry reforming reaction stems from two points: first, the CH4 and CO2 emissions from fossil fuel consumption exacerbate global warming, necessitating an efficient conversion pathway; second, syngas can be further used to produce chemical feedstocks such as methanol and olefins, realizing the "carbon resource utilization." Traditional nickel-cerium dioxide catalysts have attracted much attention due to their excellent catalytic performance and stability. However, as research has deepened, their shortcomings have gradually become apparent: First, catalyst deactivation due to sintering. At high temperatures, Ni nanoparticles are prone to agglomeration and growth (i.e., "sintering"), leading to a sharp reduction in the number of active sites and causing rapid catalyst failure. Second, severe carbon deposition. The cracking of CH4 on the Ni surface easily produces carbon species (such as carbon deposits and carbon fibers). These carbons cover active sites and block catalyst pores, directly causing catalyst "poisoning" and deactivation. Third, poor stability of the CeO2 support. At high temperatures, CeO2 is prone to grain growth, which significantly reduces its oxygen storage / release capacity, further weakening the overall performance of the catalyst.

[0003] Chinese patent CN114733528A discloses a method for preparing and applying a nickel / cerium oxide catalyst. At room temperature, a cerium salt solution and an alkaline precipitant solution are mixed and stirred for 10-30 minutes before being transferred to a reaction vessel for reaction. The resulting product A is washed with deionized water, centrifuged, and dried to obtain a basic cerium carbonate precursor. At room temperature, the basic cerium carbonate precursor is dissolved in a sodium hydroxide solution, and a nickel salt solution is slowly added dropwise. After the addition is complete, stirring continues for 30-40 minutes, and the mixture is aged at 20-25°C for 2-4 days to obtain product B. Product B is then washed, centrifuged, vacuum dried, and calcined to obtain the nickel / cerium oxide catalyst. This patent describes a long preparation time for the nickel / cerium oxide catalyst, and the use of a large amount of rare earth oxide cerium oxide as a precursor, along with the method of adjusting catalyst properties by loading a small amount of nickel, leads to a significant waste of rare earth resources. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a trans-cerium dioxide-nickel catalyst. The trans-cerium dioxide-nickel catalyst prepared by this method has excellent catalytic activity and thermal stability. This invention also provides applications of the trans-cerium dioxide-nickel catalyst.

[0005] The preparation method of the trans-cerium dioxide-nickel catalyst of the present invention includes the following steps:

[0006] (1) Nickel nitrate, polyvinylpyrrolidone, ethylene glycol, urea and water are mixed and subjected to hydrothermal reaction, then separated to obtain the reaction product;

[0007] (2) The reaction products were washed, dried, calcined, and cooled to obtain the catalyst precursor;

[0008] (3) Water is added to the catalyst precursor to disperse it, resulting in a turbid liquid. Cerium nitrate is added to the turbid liquid to dissolve it, and the mixture is heated to obtain a solid product.

[0009] (4) The solid product was calcined, cooled, and reduced to obtain a trans-cerium dioxide-nickel catalyst.

[0010] In step (1), the ratio of the number of moles of nickel nitrate to the total volume of water and ethylene glycol is 1:11-15, where nickel nitrate is expressed in mol and the total volume of water and ethylene glycol is expressed in L.

[0011] In step (1), the volume ratio of water to ethylene glycol is 1:0.5-0.75, and the ratio of nickel nitrate, polyvinylpyrrolidone and urea is 1:250-300:300-350. Nickel nitrate is expressed in mol, while polyvinylpyrrolidone and urea are expressed in g.

[0012] In step (1), the hydrothermal reaction temperature is 160-240℃ and the hydrothermal reaction time is 12-24 hours.

[0013] In step (2), the drying temperature is 60-80℃ and the drying time is 12-14 hours.

[0014] In step (2), the calcination temperature is 400-500℃, the calcination time is 2-4 hours, the calcination heating rate is 2-5℃ / min, and the cooling is natural cooling to room temperature.

[0015] In step (3), the mass of cerium in cerium nitrate is 1-10% of the mass of the catalyst precursor, the heating temperature is 70-90℃, and the heating time is 3-5 hours.

[0016] In step (3), the ratio of catalyst precursor to water is 1:20-80, where the catalyst precursor is expressed in g and the water in mL.

[0017] In step (4), the calcination temperature is 400-500℃, the calcination time is 2-4 hours, the calcination heating rate is 2-5℃ / min, and the cooling is natural cooling to room temperature.

[0018] In step (4), the reduction reaction atmosphere is hydrogen atmosphere, the reduction reaction temperature is 550-650℃, and the reduction reaction time is 1.5-2.5 hours.

[0019] In step (4), the particle size of CeO2 in the trans-cerium dioxide-nickel catalyst is 6.56-18.18 nm.

[0020] The trans-cerium dioxide-nickel catalyst prepared by the method described in this invention is used in the dry reforming of methane and carbon dioxide.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) Traditional nickel-cerium catalysts use CeO2 as the substrate and Ni as the active metal. Small-sized Ni particles are prone to Oswald ripening, which leads to agglomeration and catalyst deactivation. However, the trans-cerium dioxide-nickel catalyst (trans-CeO2-Ni catalyst) in this invention uses CeO2 as the metal active site and Ni as the catalyst support. CeO2 is anchored on a continuous Ni substrate. Compared with the ripening driving force of Ni in traditional nickel-cerium catalysts, the ripening driving force of CeO2 is significantly reduced, the kinetic process is severely hindered, and agglomeration is not easy, so the catalyst maintains high activity. In traditional nickel-cerium catalysts, although Ni particles are supported on a CeO2 substrate, the interaction between the two is mostly weak. At high temperatures, high surface energy Ni atoms or small Ni subclusters have strong migration capabilities on the CeO2 surface. When Ni atoms detach from the CeO2 surface, they diffuse on the CeO2 surface and are captured by another larger Ni particle, resulting in agglomeration. However, in the trans-CeO2-Ni catalyst of this invention, CeO2 is firmly "anchored" to the continuous Ni substrate through strong chemical bonds. The small-sized CeO2 has more sufficient contact with the Ni substrate and stronger interaction forces. At the same time, CeO2 itself has high stability and a large migration energy barrier on the Ni surface, which significantly reduces the ripening driving force of CeO2, making CeO2 less prone to agglomeration.

[0023] (2) The small-sized CeO2 in this invention has extremely high specific surface area and surface energy, and is in a thermodynamically metastable state. This high-energy state greatly reduces the formation energy of oxygen vacancies (i.e., oxygen defects), enabling CeO2 to spontaneously generate a large number of oxygen vacancies, while promoting the generation of more CeO2. 4+ Restored to Ce 3+To release lattice strain, CeO2 transitions from a metastable to a stable state. Numerous dense oxygen vacancies serve as active sites for oxygen storage and release in CeO2, significantly enhancing oxygen migration and exchange rates, thus endowing the catalyst with superior redox capabilities. By constructing a strong metal-support interaction interface between CeO2 and Ni, atomic-level control of CeO2 grain growth is achieved: thermodynamically, the CeO2 / Ni interface energy is significantly lower than the surface energy of CeO2 itself, allowing the system to reach a low-energy state through a stable interface configuration, eliminating the driving force for grain growth; kinetically, the Ni substrate acts as an inert barrier, isolating CeO2 and allowing it to grow in a stable state. 4+ / O 2- The activation energy for cross-interface migration is increased to an insurmountable level, thereby blocking the mass transport path of Oswald ripening, preventing CeO2 grain growth, and stabilizing CeO2 in a small size state (particle size of 6.56-18.18 nm). Therefore, this invention fundamentally overcomes the bottleneck problem of reduced oxygen vacancies and decreased oxygen storage / release capacity caused by grain growth and near-perfect structural stability of traditional large-size CeO2 at high temperatures.

[0024] (3) When the trans-CeO2-Ni catalyst of the present invention is used in the dry reforming reaction of methane and carbon dioxide, the metallic Ni substrate is responsible for activating and cracking CH4 to generate surface carbon species, while the CeO2 active sites are responsible for providing oxygen vacancies to activate CO2 and providing active oxygen species in the reaction (surface adsorbed active oxygen formed after CO2 dissociates from oxygen vacancies and lattice oxygen activated and migrated in CeO2 lattice). These active oxygen species will immediately remove the surface carbon species that migrate to the CeO2-Ni interface and oxidize them to the target product CO, thereby efficiently eliminating them before carbon deposition occurs and realizing a "carbon removal" cycle at the interface; the trans-CeO2-Ni catalyst induces electron transfer from Ni to CeO2 through strong metal-support interaction. The Ni surface is made electron-deficient. This electron-deficient state weakens the deep dissociation ability of Ni on CH bonds, reducing the formation of graphitic carbon precursors at the source. On the other hand, it enhances the polarity of Ni-C bonds, making adsorbed carbon species more susceptible to nucleophilic attack. This significantly improves the oxidation and scavenging efficiency of carbon species by reactive oxygen species at the interface, thus inhibiting carbon deposition from both the source and process aspects and significantly improving the catalyst's resistance to carbon deposition. CeO2 is dispersed on the Ni support with extremely high utilization rate. Almost every cerium site can be exposed as an active site to participate in the reaction. At the same time, this highly dispersed state causes strong electronic interactions between cerium atoms and the surrounding environment, leading to changes in the electronic structure of cerium atoms and significantly enhancing their variable valence state (CeO2). 3+ / Ce 4+The high cycling efficiency and fluidity of lattice oxygen enable the limited cerium sites to possess a highly efficient oxygen storage and release capacity far exceeding their loading capacity. This allows for the continuous and rapid supply of active oxygen during the reaction to remove surface carbon species and carbon deposits, ultimately achieving excellent catalytic effects with a low Ce content. This is of great significance for the utilization of rare earth resources. Attached Figure Description

[0025] Figure 1 This is a transmission electron microscope (TEM) image of the trans-CeO2-Ni catalyst.

[0026] Figure 2 This is a graph showing the CH4 conversion rate versus temperature during the dry reforming of methane and carbon dioxide.

[0027] Figure 3 The thermogravimetric analysis (TGA) diagrams of the catalysts in Example 1 and Comparative Example 1 are shown, where a is the TGA diagram of the catalyst in Comparative Example 1 and b is the TGA diagram of the catalyst in Example 1.

[0028] Figure 4 The images show the X-ray diffraction patterns of the catalysts in Example 1 and Comparative Example 1. Detailed Implementation

[0029] The present invention will be further described below with reference to embodiments.

[0030] Example 1

[0031] (1) Weigh 1.5g of polyvinylpyrrolidone and dissolve it in 40mL of deionized water. Add 30mL of ethylene glycol and stir for 30min to completely dissolve the polyvinylpyrrolidone. Then add 1.746g of nickel nitrate hexahydrate and 1.8g of urea and continue stirring for 30min to make the solution clear and transparent. After stirring, transfer the above solution to a 100mL reactor for hydrothermal reaction. Set the temperature to 160℃ and the reaction time to 12 hours. After the reaction is completed, separate the reaction products.

[0032] (2) The reaction product was washed four times with 600 mL of deionized water and then dried in a blast drying oven at 70 °C for 12 hours. It was then ground into powder and placed in a muffle furnace and heated (heating rate of 2 °C / min) to 400 °C for 2 hours. It was then naturally cooled to room temperature to obtain the NiO precursor.

[0033] (3) Add 25 mL of deionized water to 0.5 g NiO precursor. Under the combined action of ultrasound and stirring, the NiO precursor is fully dispersed to obtain a turbid liquid. Add 0.0155 g of cerium nitrate hexahydrate to the turbid liquid and dissolve it completely. Then transfer it to an oil bath and heat it at 80 °C. Stir for 4 hours until all the water evaporates to obtain a solid product.

[0034] (4) The solid product was ground into powder and placed in a muffle furnace and heated to 400°C for 2 hours (heating rate of 2°C / min) to obtain CeO2-NiO catalyst. After natural cooling to room temperature, it was heated to 600°C and reduced for 2 hours in a mixed atmosphere of hydrogen and argon to obtain trans-CeO2-Ni catalyst. Since the mass of cerium in cerium hexahydrate in step (3) is 1% of the mass of NiO precursor, the obtained trans-CeO2-Ni catalyst is recorded as 1%CeO2-Ni catalyst. The interplanar spacing of CeO2(111) crystal plane is 0.31 nm, and the particle size of CeO2 is 6.56-18.18 nm. The transmission electron microscope image of the trans-CeO2-Ni catalyst is shown in the figure. Figure 1 .

[0035] Example 2

[0036] (1) Weigh 1.8g of polyvinylpyrrolidone and dissolve it in 60mL of deionized water. Add 30mL of ethylene glycol and stir for 30min to completely dissolve the polyvinylpyrrolidone. Then add 1.746g of nickel nitrate hexahydrate and 2.1g of urea and continue stirring for 30min to make the solution clear and transparent. After stirring, transfer the above solution to a 100mL reactor for hydrothermal reaction. Set the temperature to 240℃ and the reaction time to 18 hours. After the reaction is completed, separate the reaction products.

[0037] (2) The reaction product was washed 4 times with 600 mL of deionized water and then dried in a blast drying oven at 60 °C for 13 hours. Then it was ground into powder and placed in a muffle furnace and heated (heating rate of 5 °C / min) to 500 °C for 3 hours. After natural cooling to room temperature, NiO precursor was obtained.

[0038] (3) Add 25 mL of deionized water to 0.5 g NiO precursor. Under the combined action of ultrasound and stirring, the NiO precursor is fully dispersed to obtain a turbid liquid. Add 0.0775 g of cerium nitrate hexahydrate to the turbid liquid and dissolve it completely. Then transfer it to an oil bath and heat it at 90 °C. Stir for 3 hours until all the water evaporates to obtain a solid product.

[0039] (4) The solid product is ground into powder and placed in a muffle furnace and heated to 500°C for 3 hours (heating rate is 5°C / min) to obtain CeO2-NiO catalyst. It is then naturally cooled to room temperature and heated to 650°C for 1.5 hours under a mixed atmosphere of hydrogen and argon to obtain trans CeO2-Ni catalyst. Since the mass of cerium in cerium hexahydrate in step (3) is 5% of the mass of NiO precursor, the trans CeO2-Ni catalyst obtained is recorded as 5% CeO2-Ni catalyst.

[0040] Example 3

[0041] (1) Weigh 1.65g of polyvinylpyrrolidone and dissolve it in 50mL of deionized water. Add 30mL of ethylene glycol and stir for 30min to completely dissolve the polyvinylpyrrolidone. Then add 1.746g of nickel nitrate hexahydrate and 1.95g of urea and continue stirring for 30min to make the solution clear and transparent. After stirring, transfer the above solution to a 100mL reactor for hydrothermal reaction. Set the temperature to 200℃ and the reaction time to 24 hours. After the reaction is completed, separate the reaction products.

[0042] (2) The reaction product was washed four times with 600 mL of deionized water and then dried in an oven at 80 °C for 14 hours. It was then ground into powder and placed in a muffle furnace and heated (heating rate of 3 °C / min) to 450 °C for 4 hours. After cooling naturally to room temperature, NiO precursor was obtained.

[0043] (3) Add 25 mL of deionized water to 0.5 g NiO precursor. Under the combined action of ultrasound and stirring, the NiO precursor is fully dispersed to obtain a turbid liquid. Add 0.1549 g of cerium nitrate hexahydrate to the turbid liquid and dissolve it completely. Then transfer it to an oil bath and heat it at 70 °C. Stir for 5 hours until all the water evaporates to obtain a solid product.

[0044] (4) The solid product is ground into powder and placed in a muffle furnace and heated to 450°C for 4 hours (heating rate is 3°C / min) to obtain CeO2-NiO catalyst. It is then naturally cooled to room temperature and heated to 550°C for 2.5 hours under a mixed atmosphere of hydrogen and argon to obtain trans CeO2-Ni catalyst. Since the mass of cerium in cerium hexahydrate in step (3) is 10% of the mass of NiO precursor, the obtained trans CeO2-Ni catalyst is recorded as 10% CeO2-Ni catalyst.

[0045] Comparative Example 1

[0046] (1) Weigh 21.6g of sodium hydroxide and place it in the lining of a 100mL reactor. Add 60mL of deionized water and stir for 15min to obtain a concentrated sodium hydroxide solution. Weigh 1.95g of cerium nitrate hexahydrate and dissolve it in 30mL of deionized water to obtain a clear and transparent solution. Add the clear and transparent solution to the concentrated sodium hydroxide solution and then transfer it to the reactor for hydrothermal reaction. Set the temperature to 180℃ and the reaction time to 24 hours. After the reaction is completed, separate the reaction product I.

[0047] (2) The reaction product I was washed 4 times with 600 mL of deionized water and then dried in a blast drying oven at 70 °C for 12 hours. It was then ground into powder and placed in a muffle furnace and heated (heating rate of 2 °C / min) to 400 °C for 2 hours. It was then naturally cooled to room temperature to obtain CeO2 precursor.

[0048] (3) Add 25 mL of deionized water to 0.5 g of CeO2 precursor. Under the combined action of ultrasound and stirring, the CeO2 precursor is fully dispersed to obtain a turbid liquid. Weigh 0.0248 g of nickel nitrate hexahydrate and dissolve it in 25 mL of deionized water to obtain solution A. Weigh 0.53 g of anhydrous sodium carbonate and dissolve it in 20 mL of deionized water to obtain solution B. Add solution A dropwise to the turbid liquid, and add solution B dropwise at the same time until solution A is completely added, so that the pH of the solution is 9. Separate to obtain reaction product II. Aged reaction product II for 2 hours, washed 4 times with 600 mL of deionized water, and dried in a 70℃ drying oven for 12 hours to obtain a solid product.

[0049] (4) The solid product is ground into powder and placed in a muffle furnace and heated to 400°C for 2 hours (heating rate is 2°C / min) to obtain NiO-CeO2 catalyst. It is then naturally cooled to room temperature and heated to 600°C for 2 hours under a mixed atmosphere of hydrogen and argon to obtain Ni-CeO2 catalyst. Since the mass of nickel in nickel hexahydrate in step (3) is 1% of the mass of CeO2 precursor, the obtained Ni-CeO2 catalyst is recorded as 1% Ni-CeO2 catalyst.

[0050] methane-carbon dioxide dry reforming reaction experiment

[0051] Reaction conditions:

[0052] The reaction temperature was 790-810℃, and experiments were conducted at 790℃, 792℃, 794℃, 796℃, 798℃, 800℃, 802℃, 804℃, 806℃, 808℃ and 810℃ respectively; the reaction pressure was 0.1MPa; the catalysts were the 1%CeO2-Ni catalyst prepared in Example 1 and the 1%Ni-CeO2 catalyst prepared in Comparative Example 1, with a catalyst mass of 0.25g; the volume ratio of CH4 to CO2 in the reaction feed gas was 1:1; and the flow rates of CH4 and CO2 were both 50mL / min.

[0053] Experimental steps:

[0054] Weigh 0.25g of catalyst powder and place it into a quartz reaction tube with an inner diameter of 6mm. Place quartz wool at both ends of the reaction tube and introduce the reaction raw material gas. Analyze the peak area values ​​of each reactant before the reaction using a gas chromatograph. Collect the composition and content of the tail gas at different reaction times online using a gas chromatograph and perform calculation and analysis. After the reaction is completed, switch the reaction raw material gas to nitrogen, stop heating, and allow it to cool down naturally.

[0055] CH4 conversion rate The calculation formula is as follows:

[0056] ,

[0057] In the formula, This indicates the flow rate at the CH4 inlet. This indicates the flow rate at the CH4 outlet.

[0058] The experimental results of the dry reforming reaction of methane and carbon dioxide are shown in Table 1. The CH4 conversion rate versus temperature change graph in the dry reforming reaction of methane and carbon dioxide is shown in Table 1. Figure 2 .

[0059] Table 1. Experimental results of the dry reforming reaction of methane and carbon dioxide.

[0060]

[0061] As shown in Table 1, at 790-810℃, the CH4 conversion rate of the 1%CeO2-Ni catalyst is much higher than that of the 1%Ni-CeO2 catalyst, which fully demonstrates that the low-cerium-content trans-CeO2-Ni catalyst exhibits higher activity than the traditional Ni-CeO2 catalyst in the high-temperature methane-carbon dioxide dry reforming reaction.

[0062] The trans-CeO2-Ni catalyst prepared by this invention, with only a small amount of CeO2 loaded, can significantly improve the catalyst activity and maintain a high conversion rate of methane compared with the traditional nickel-cerium catalyst, which is of great significance for the full utilization of rare earth resources.

[0063] Thermogravimetric analysis test

[0064] Thermogravimetric analysis (TG) was used to study the thermal stability of the 1% CeO2-Ni catalyst prepared in Example 1 and the 1% Ni-CeO2 catalyst prepared in Comparative Example 1. The catalyst samples after reaction were placed in a sample crucible in a high-temperature furnace and heated from room temperature to 800°C at a constant heating rate in air atmosphere. Simultaneously, the mass change of the samples was monitored in real time. The degree of carbon deposition was quantitatively assessed by comparing the total weight loss rate of different catalysts during the heating process. The thermogravimetric analysis figures of the catalysts in Example 1 and Comparative Example 1 are shown below. Figure 3 .

[0065] The results showed that the 1%Ni-CeO2 catalyst exhibited significant weight loss in the intermediate temperature range, with a total weight loss rate of 28.7542%, while the total weight loss rate of the 1%CeO2-Ni catalyst (20.5524%) was significantly lower than that of the 1%Ni-CeO2 catalyst, indicating that the 1%CeO2-Ni catalyst can reduce carbon deposition to a certain extent.

[0066] X-ray diffraction test

[0067] X-ray diffraction tests were performed using a PANalytical X'pert3 powder diffractometer. The powder sample was placed on a glass slide and the surface was flattened. The tests were conducted using a CuKα radiator (λ=0.15418nm) at 40kV and 40mA. The diffraction angle range during the tests was 10° to 90°. The X-ray diffraction patterns of the catalysts in Example 1 and Comparative Example 1 are shown below. Figure 4 .

[0068] The results show that the 1%CeO2-Ni catalyst in Example 1 only exhibited obvious diffraction peaks corresponding to metallic nickel, and no obvious CeO2 diffraction peaks were observed. This indicates that CeO2 exists as extremely small nanoparticles or in a highly dispersed amorphous form, thus demonstrating that the CeO2 phase is highly dispersed on the Ni substrate and has not agglomerated to form large crystals. Similarly, the 1%Ni-CeO2 catalyst in Comparative Example 1 only exhibited obvious diffraction peaks corresponding to the cerium oxide fluorite phase, and no obvious metallic Ni diffraction peaks were observed, indicating that Ni is highly dispersed on the CeO2 support. Therefore, it can be concluded that the active sites of the catalysts in Example 1 and Comparative Example 1 are highly dispersed on the support.

Claims

1. The application of a trans-cerium dioxide-nickel catalyst in the dry reforming of methane and carbon dioxide, wherein the trans-cerium dioxide-nickel catalyst uses CeO2 as the metal active site and Ni as the catalyst support, characterized in that... The preparation method of the trans-cerium dioxide-nickel catalyst includes the following steps: (1) Nickel nitrate, polyvinylpyrrolidone, ethylene glycol, urea and water are mixed and subjected to hydrothermal reaction, then separated to obtain the reaction product; (2) The reaction products were washed, dried, calcined, and cooled to obtain the catalyst precursor; (3) Water is added to the catalyst precursor to disperse it, resulting in a turbid liquid. Cerium nitrate is added to the turbid liquid to dissolve it, and the mixture is heated to obtain a solid product. (4) The solid product was calcined, cooled, and reduced to obtain a trans-cerium dioxide-nickel catalyst; In step (3), the mass of cerium in cerium nitrate is 1-10% of the mass of the catalyst precursor; In step (4), the reduction reaction temperature is 550-650℃, and the particle size of CeO2 in the trans-cerium dioxide-nickel catalyst is 6.56-18.18nm.

2. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (1), the ratio of the number of moles of nickel nitrate to the total volume of water and ethylene glycol is 1:11-15, where nickel nitrate is expressed in mol and the total volume of water and ethylene glycol is expressed in L.

3. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (1), the volume ratio of water to ethylene glycol is 1:0.5-0.75, and the ratio of nickel nitrate, polyvinylpyrrolidone and urea is 1:250-300:300-350. Nickel nitrate is expressed in mol, while polyvinylpyrrolidone and urea are expressed in g.

4. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (1), the hydrothermal reaction temperature is 160-240℃ and the hydrothermal reaction time is 12-24 hours.

5. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (2), the drying temperature is 60-80℃ and the drying time is 12-14 hours.

6. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (2), the calcination temperature is 400-500℃ and the calcination time is 2-4 hours.

7. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (3), the heating temperature is 70-90℃ and the heating time is 3-5 hours.

8. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (4), the calcination temperature is 400-500℃ and the calcination time is 2-4 hours.

9. The application of the trans-cerium dioxide-nickel catalyst according to claim 1 in the dry reforming of methane and carbon dioxide, characterized in that... In step (4), the reduction reaction atmosphere is hydrogen atmosphere, and the reduction reaction time is 1.5-2.5 hours.

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