A perovskite oxide modified supported ni-based catalyst, and a preparation method and application thereof

Abstract

The present application relates to a kind of perovskite oxide modified supported Ni-based catalyst and its preparation method and application.Catalyst composition is Ni-MO x -ABO3 / supporter, wherein Ni is the active component of catalyst;ABO3 is perovskite structure, A is Ca, Sr, or combination of Ca and Sr, B is Ti or Zr;MO x Is an auxiliary component, and the component is La2O3 or CeO2;Supporter is TiO2, ZrO2, TiO2-SiO2 or ZrO2-SiO2.Directly use the component of supporter and load alkaline earth metal element to react, perovskite oxide is generated in situ on the surface of supporter, promote the interaction of perovskite and supporter, and it is beneficial to the oxygen vacancy generated by perovskite to promote carbon dioxide activation.Loaded Ni is used as catalyst for CO2 methanation reaction, and it shows high activity while also having good stability.CO2 Methanation reaction conversion rate can reach 90%, and stability test 100h does not deactivate.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, and more specifically, to a perovskite oxide-modified supported Ni-based catalyst, its preparation method, and its application in the field of CO2 methanation. Background Technology

[0002] With economic development, the massive consumption of fossil fuels has led to substantial CO2 emissions. As a greenhouse gas, excessive CO2 emissions have caused global warming, sea-level rise, and other climate problems, exacerbating the instability of the climate system. To protect the ecological environment, it is imperative to control CO2 emissions in a reasonable manner. Currently, the main technologies used for emission reduction include CO2 capture, separation, storage, and recycling. Among these, CO2 recycling reduces carbon emissions while simultaneously realizing the resource utilization of CO2.

[0003] Compared to the combustion of fossil fuels, the combustion of renewable energy is cleaner and more efficient. Replacing fossil fuels with renewable energy can effectively reduce carbon emissions. However, renewable energy sources, primarily wind and solar power, are seasonal. Excess during peak seasons leads to energy waste, while insufficient supply during off-seasons. This mismatch between electricity supply and demand urgently necessitates efficient energy storage technologies. Excess renewable energy can be converted into hydrogen (H2) through water electrolysis. H2 has a high energy density (9.7 MJ / m³). 3 Hydrogen is considered an ideal energy storage material. However, due to the risks of hydrogen storage and transportation, using hydrocarbons as energy carriers is one of the most promising approaches. Methane (CH4) has a high energy density (32.8 MJ / m³). 3 Furthermore, methane possesses a well-developed transportation and distribution system, making it an ideal energy storage substance. In addition, besides being a high-quality fuel, methane is also a raw material for synthesizing various chemicals, offering a broad application market. Therefore, using a highly efficient and appropriate catalyst to catalyze the conversion of CO2 to CH4 reduces carbon emissions, contributing to controlling global warming; furthermore, the generated CH4 is a highly efficient energy storage substance, overcoming the inherent intermittency of renewable energy sources. By coupling electrical and chemical energy, locally surplus renewable energy is combined with the greenhouse gas CO2 to convert it into CH4, achieving multiple benefits. In conclusion, CO2 hydrogenation to methane, as a technology that can simultaneously utilize greenhouse gas resources and store renewable energy, has promising application prospects and research value.

[0004] Currently, reported catalysts for CO2 methanation are those with metals such as Ru, Pt, Pd, Rh, Ni, Co, and Fe as active components. Among them, noble metal catalysts such as Ru and Rh exhibit excellent performance and good resistance to carbon deposition, but their high price limits their industrial application. Ni-based catalysts, on the other hand, possess relatively high activity and selectivity, are inexpensive, and readily available, thus showing potential for industrial application and attracting widespread attention from researchers. However, research has revealed several issues that still limit the industrial application of Ni-based catalysts. Firstly, because CO2 molecules are very stable and inert compounds, with carbon atoms in their highest oxidation state, they are difficult to activate at low temperatures. Therefore, improving the low-temperature activity of the catalyst is a key problem to be solved. Secondly, CO2 methanation is a strongly exothermic reaction, and Ni-based catalysts suffer from the problem of active metal sintering during the reaction.

[0005] Perovskite-type oxides (PTOs), typically represented by the structural formula ABO3, exhibit good thermal and chemical stability. Their chemical composition and crystal structure can be flexibly adjusted; by modifying the A-site and B-site elements, the structure and properties of the perovskite can be controlled to better meet catalytic requirements. Furthermore, the metal ions in ABO3 are uniformly mixed at the atomic level, leading to strong interactions between the metals after reduction. Additionally, oxygen vacancies readily form on the perovskite surface, which is beneficial for CO2 activation. In summary, perovskite oxides can be considered excellent catalyst materials and precursors for CO2 catalytic conversion.

[0006] Pure perovskites synthesized by conventional methods such as citric acid complexation and autogenous combustion typically have a small specific surface area, which is detrimental to the dispersion of surface-active components. To address this issue, perovskites are usually loaded onto the surface of a support with a higher specific surface area. Li et al. prepared SiO2-supported perovskite LaNi 1-x Mo x O3 precursor, after reduction, Ni nanoparticles are in close contact and highly dispersed with La2O3 and MoO3, exhibiting good CO2 methanation activity as well as good anti-sintering ability [Li S, Guo S, Gong D, et al. Nano composite composed of MoO3]. x -La2O3-Ni on SiO2 for storing hydrogen into CH4 via CO2methanation[J].International Journal of HydrogenEnergy, 2019,44(3):1597-1609.]; Song et al. 1-x Cox O3 was supported on the ZrO2 surface, and the resulting Co nanoparticles and LaAlO3 were highly dispersed on the support surface after reduction. The catalyst exhibited good activity in the hydrogenation of CO to lower alcohols [Song P, Fang Y, Liu X, et al. LaAlO3-Tailored Active Pairs of Co]. 0 –Co δ+ Supported on ZrO2 for Higher Alcohol Synthesis from Syngas[J].Ind.Eng.Chem.Res.,2023,62:16696-16706.]. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of low activity and poor stability of existing CO2 methanation catalysts, and to provide a perovskite oxide-modified supported Ni-based catalyst and its preparation method. When used in CO2 methanation reaction, it exhibits good activity and anti-sintering properties.

[0008] To improve the low-temperature activity and stability of the catalyst, this invention directly utilizes the reaction between the support component and the supported alkaline earth metal element to generate perovskite oxide in situ on the support surface. This further promotes the interaction between the perovskite and the support, enhances the high dispersion of the perovskite, and facilitates the generation of abundant oxygen vacancies in the perovskite, thus promoting carbon dioxide activation. Simultaneously, Ni is supported as a catalyst for the CO2 methanation reaction, exhibiting high activity and good stability.

[0009] To address the above objectives, the present invention provides the following technical solution:

[0010] A supported metal catalyst modified with perovskite oxide, the catalyst having a Ni-MO composition. x -ABO3 / support, where Ni is the active component of the catalyst, accounting for 5-20% of the catalyst's mass fraction; ABO3 has a perovskite structure, accounting for 6-40% of the catalyst's mass fraction; A is Ca, Sr, or a combination of Ca and Sr; when Ca and Sr are combined, the molar ratio Ca:Sr = 1:(0.01~99); B is Ti or Zr; the molar ratio A:B = 1:1; MO x As an auxiliary agent, the composition is La2O3 or CeO2, accounting for 0-12% of the catalyst by mass; the support is TiO2, ZrO2, TiO2-SiO2 or ZrO2-SiO2, accounting for 28-89% of the catalyst by mass.

[0011] in MO x Under conditions where there is no additive, the catalyst structure is: Ni-ABO3 / support.

[0012] in MO x Under conditions where the additive content is not zero, the catalyst structure is: Ni-MO x -ABO3 / carrier; MO x The preferred mass fraction of the additives is 1-12%.

[0013] The method for preparing the perovskite oxide-modified supported metal catalyst of the present invention includes the following steps:

[0014] 1) Dissolve nickel nitrate, perovskite A-site corresponding metal nitrate, nitrate added as an auxiliary agent, and citric acid in distilled water to obtain a mixed solution, wherein the molar ratio of all nitrates to citric acid is 1:(1~3); immerse an equal volume of the dissolved solution on a carrier and seal it for 12~48h;

[0015] 2) Unseal the carrier from step 1), place it in a constant temperature drying oven at 50–90℃ for 2–10 hours, and then at 100–150℃.

[0016] The dried product is obtained by drying overnight.

[0017] 3) Calcine the dried product obtained in step 2) at 250-400℃ for 1-6 hours, and then continue to calcine at 550-900℃ for 3-10 hours to obtain the catalyst precursor;

[0018] 4) Place the catalyst precursor obtained in step 3) in a reactor, introduce reducing gas into the reactor to reduce the catalyst precursor, and obtain catalyst Ni-ABO3 / support or Ni-MO. x -ABO3 / vector.

[0019] In step 1), the metal nitrate corresponding to the perovskite A site is one of calcium nitrate or strontium nitrate, or a mixture of calcium nitrate and strontium nitrate, wherein the molar ratio of the mixture is calcium nitrate: strontium nitrate = 1:(0.01~99).

[0020] The nitrate added to the auxiliary agent in step 1) is lanthanum nitrate or cerium nitrate.

[0021] In step 3), the product is calcined at 250-400℃ for 1-6 hours, and then further heated to 550-900℃ for 3-10 hours at a heating rate of 1-10℃ / min.

[0022] In step 4), the rate of introducing reducing gas is 10-30 mL / min, the reduction time is 1-3 h, the reduction temperature is 400-700 °C, and the heating rate is 1-10 °C / min.

[0023] In step 4), the reducing gas is hydrogen or carbon monoxide; or a mixture of an inert gas and one or two of hydrogen or carbon monoxide; the volume percentage of the inert gas in the mixed gas atmosphere is 1%-99%.

[0024] The perovskite oxide-modified supported metal catalyst of the present invention is applied to the CO2 methanation reaction.

[0025] The perovskite oxide-modified supported metal catalyst described above is applied to the CO2 methanation reaction; the catalyst is added to a fixed-bed reactor, and under conditions of 200–600 °C and 1–5 MPa, it is added to the reactor at a volume hourly space velocity (VHSV) of 3000–60000 mL / (g). cat h) Introduce carbon dioxide and hydrogen gas, wherein the molar ratio of carbon dioxide to hydrogen gas is 1:(1-5); to obtain the target product methane.

[0026] The perovskite oxide-modified supported metal catalyst of this invention is applied to CO2 methanation. The catalyst is added to a fixed-bed reactor at a temperature of 200–600°C and a pressure of 1–5 MPa, with a volume hourly space velocity (VHSV) of 3000–60000 mL / (g). cat h) Carbon dioxide and hydrogen are introduced, with a molar ratio of carbon dioxide to hydrogen of 1:(1-5). The target product, methane, is obtained. The CO2 conversion rate reaches 90%, and the methane selectivity is 100%.

[0027] As described above, the preparation method and application of the perovskite oxide-modified supported Ni-based catalyst of the present invention have the following beneficial effects:

[0028] (1) The perovskite oxide-modified supported Ni-based catalyst of the present invention is prepared by an equal-volume impregnation method combined with high-temperature calcination, which is simple and easy to operate.

[0029] (2) This invention utilizes the solid-phase reaction between the loaded alkaline earth metal elements and the elements on the surface of the support to generate perovskite, thereby highly dispersing the perovskite oxide on the catalyst surface and utilizing the oxygen vacancies on the perovskite surface to promote CO2 activation.

[0030] (3) When the catalyst prepared in this invention is applied to the CO2 methanation reaction, it can exhibit good activity and stability. The CO2 methanation reaction conversion rate can reach 90%, and the stability test shows no deactivation after 100h, which has certain industrialization prospects. Attached Figure Description

[0031] Figure 1 The images show the X-ray diffraction (XRD) patterns of the catalysts after calcination in Examples 1, 2, 5, and 6.

[0032] Figure 2 The images show the Raman spectra of Examples 5 and 7 and the Ni / ZrO2 catalyst.

[0033] Figure 3 This is a high-resolution TEM image of the catalyst in Example 7.

[0034] Figure 4 The results show the stability test results of the catalyst in the CO2 methanation reaction in Example 5. The reaction conditions were: H2:CO2 composition = 4:1, reaction pressure = 3 MPa, and reaction space velocity = 15000 mL g cat. -1 h -1 .

[0035] Figure 5 The X-ray diffraction (XRD) patterns of the catalysts after calcination in Examples 15 and 16 are shown below. Detailed Implementation

[0036] Example 1

[0037] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:1:2.4, wherein 0.495 g of nickel nitrate is weighed out. Immerse it onto 0.805 g of ZrO2 support and seal for 24 h.

[0038] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0039] 3) After drying, the product is heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor NiO-CaZrO3 / ZrO2.

[0040] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550℃ for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2℃ / min to obtain a 10% Ni-CaZrO3 / ZrO2 catalyst, wherein the mass fraction of Ni was 10% and the mass fraction of CaZrO3 was 31%. Figure 1 The XRD pattern shows that the catalyst exhibits a perovskite structure.

[0041] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0042] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0043] At 250℃, the CO2 conversion rate was 53.8%; at 300℃, the CO2 conversion rate was 75.8%; and at 350℃, the CO2 conversion rate was 86.5%. At all these temperatures, the CH4 selectivity was 100%.

[0044] Example 2

[0045] 1) Prepare a mixed salt solution of nickel nitrate, strontium nitrate, and citric acid in a molar ratio of 1:1:2.4, wherein 0.495 g of nickel nitrate is weighed out. Immerse it onto 0.715 g of ZrO2 support and seal for 24 h.

[0046] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0047] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 10% Ni-SrZrO3 / ZrO2.

[0048] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550℃ for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2℃ / min to obtain a 10% Ni-SrZrO3 / ZrO2 catalyst, wherein the mass fraction of Ni was 10% and the mass fraction of SrZrO3 was 40%. Figure 1 The XRD pattern shows that the catalyst exhibits a perovskite structure.

[0049] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0050] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0051] At 250℃, the CO2 conversion rate was 46.2%; at 300℃, the CO2 conversion rate was 72.6%; and at 350℃, the CO2 conversion rate was 85.9%. At all these temperatures, the CH4 selectivity was 100%.

[0052] Example 3

[0053] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, strontium nitrate, and citric acid in a molar ratio of 1:0.2:0.2:1.68, wherein 0.297 g of nickel nitrate is weighed out. Immerse it onto 0.907 g of ZrO2 support and seal for 24 h.

[0054] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0055] 3) After drying, the product was heated to 350℃ at a rate of 2℃ / min and calcined for 2 hours, then further heated to 700℃ and calcined for 5 hours to obtain a catalyst precursor of 6% NiO-Ca. 0.5 Sr 0.5 ZrO3 / ZrO2.

[0056] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain the catalyst 6% Ni-Ca. 0.5 Sr 0.5 ZrO3 / ZrO2, wherein the mass fraction of Ni is 6%, and Ca... 0.5 Sr 0.5 The ZrO3 mass fraction is 8%.

[0057] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was conducted by introducing CO2 and hydrogen in a molar ratio of 4:1.

[0058] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0059] At 250℃, the CO2 conversion rate was 43.5%; at 300℃, the CO2 conversion rate was 78.2%; and at 350℃, the CO2 conversion rate was 85.7%. At all these temperatures, the CH4 selectivity was 100%.

[0060] Example 4

[0061] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.86, with 0.248 g of nickel nitrate weighed out. Immerse it onto 0.931 g of ZrO2 support and seal for 12 h.

[0062] 2) Place the product in a constant temperature drying oven at 90°C for 3 hours, and then dry it overnight at 150°C to obtain the dried product;

[0063] 3) After drying, the product was heated to 400℃ at 2℃ / min and calcined for 3h, and then heated to 650℃ and calcined for 5h to obtain the catalyst precursor 5% NiO-CaZrO3 / ZrO2.

[0064] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 5% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni is 5% and the mass fraction of CaZrO3 is 6%.

[0065] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0066] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0067] At 250℃, the CO2 conversion rate was 44.2%; at 300℃, the CO2 conversion rate was 69.1%; and at 350℃, the CO2 conversion rate was 83.4%. At all these temperatures, the CH4 selectivity was 100%.

[0068] Example 5

[0069] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.68, with 0.743 g of nickel nitrate weighed out. Impregnate the solution onto 0.793 g of ZrO2 support and seal for 24 h.

[0070] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0071] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0072] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550℃ for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2℃ / min to obtain a 15% Ni-CaZrO3 / ZrO2 catalyst, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 19%. Although Figure 1 The XRD pattern did not show obvious perovskite characteristic peaks for this catalyst, but Figure 2 In the Raman spectrum, 139, 210, 247, 281, 353, 433, 455 cm⁻¹ -1 The bands shown can be attributed to CaZrO3, confirming the existence of the perovskite structure.

[0073] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0074] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0075] At 250℃, the CO2 conversion rate was 62.5%; at 300℃, the CO2 conversion rate was 80.2%; and at 350℃, the CO2 conversion rate was 87.8%. At all these temperatures, the CH4 selectivity was 100%. No inactivation was observed during a stability test at 600℃ for 100 hours, as shown in the attached figure. Figure 4 As shown.

[0076] Example 6

[0077] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.68, with 0.991 g of nickel nitrate weighed out. Immerse it onto 0.724 g of ZrO2 support and seal for 24 h.

[0078] 2) Place the product in a constant temperature drying oven at 70°C for 6 hours, and then dry it overnight at 110°C to obtain the dried product;

[0079] 3) After drying, the product was heated to 300℃ at 2℃ / min and calcined for 2h, and then heated to 650℃ and calcined for 5h to obtain the catalyst precursor 20% NiO-CaZrO3 / ZrO2.

[0080] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 20% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni is 20% and the mass fraction of CaZrO3 is 25%.

[0081] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was conducted by introducing CO2 and hydrogen in a molar ratio of 4:1.

[0082] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0083] At 250℃, the CO2 conversion rate was 53.3%; at 300℃, the CO2 conversion rate was 71.6%; and at 350℃, the CO2 conversion rate was 82.3%. At all these temperatures, the CH4 selectivity was 100%.

[0084] Example 7

[0085] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.68, with 0.743 g of nickel nitrate weighed out. Impregnate the solution onto 0.793 g of ZrO2 support and seal for 24 h.

[0086] 2) Place the product in a constant temperature drying oven at 70°C for 3 hours, and then dry it overnight at 120°C to obtain the dried product;

[0087] 3) After drying, the product was heated to 250℃ at 2℃ / min and calcined for 3h, and then heated to 550℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0088] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550℃ for 1 h in an H2 mixture at a flow rate of 30 mL / min and a heating rate of 2℃ / min to obtain a 15% Ni-CaZrO3 / ZrO2 catalyst, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 19%. Although Figure 1 The XRD pattern did not show obvious perovskite characteristic peaks for this catalyst, but Figure 2 In the Raman spectrum, 141, 206, 251, 283, 355, 433, 452 cm⁻¹ -1 The bands observed at this location can be attributed to CaZrO3, confirming the presence of the perovskite structure. Furthermore, in... Figure 3 In the high-resolution TEM image shown, in addition to the lattice fringes corresponding to Ni and m-ZrO2, lattice fringes of CaZrO3 were also observed.

[0089] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0090] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0091] At 250℃, the CO2 conversion rate was 66.2%; at 300℃, the CO2 conversion rate was 86.5%; and at 350℃, the CO2 conversion rate was 93.6%. At all these temperatures, the CH4 selectivity was 100%.

[0092] Example 8

[0093] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.68, with 0.743 g of nickel nitrate weighed out. Impregnate the solution onto 0.793 g of ZrO2 support and seal for 24 h.

[0094] 2) Place the product in a constant temperature drying oven at 50°C for 6 hours, and then dry it overnight at 100°C to obtain the dried product;

[0095] 3) After drying, the product is heated to 250℃ at 1℃ / min and calcined for 1h, and then heated to 550℃ and calcined for 3h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0096] 4) The obtained catalyst precursor was placed in a reactor and reduced at 400°C for 1 h in a 1% H2 / Ar mixed gas at a flow rate of 10 mL / min and a heating rate of 1 °C / min to obtain a catalyst of 15% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni is 15% and the mass fraction of CaZrO3 is 19%.

[0097] 5) Under a pressure of 1 MPa, the contents are introduced into the reactor at a volumetric space velocity of 3000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:5.

[0098] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0099] At 250℃, the CO2 conversion rate was 60.6%; at 300℃, the CO2 conversion rate was 75.8%; and at 350℃, the CO2 conversion rate was 89.6%. At all these temperatures, the CH4 selectivity was 100%.

[0100] Example 9

[0101] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.68, with 0.743 g of nickel nitrate weighed out. Impregnate the solution onto 0.793 g of ZrO2 support and seal for 24 h.

[0102] 2) Place the product in a constant temperature drying oven at 90°C for 6 hours, and then dry it overnight at 150°C to obtain the dried product;

[0103] 3) After drying, the product was heated to 500℃ at 10℃ / min and calcined for 6 hours, and then heated to 900℃ and calcined for 10 hours to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0104] 4) The obtained catalyst precursor was placed in a reactor and reduced at 700°C for 3 h in a 99% H2 / Ar mixed gas at a flow rate of 20 mL / min and a heating rate of 10 °C / min to obtain a catalyst of 15% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 19%.

[0105] 5) Under a pressure of 5 MPa, the contents are introduced into the reactor at a volumetric space velocity of 60,000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:1.

[0106] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0107] At 250℃, the CO2 conversion rate was 30.1%; at 300℃, the CO2 conversion rate was 57.2%; and at 350℃, the CO2 conversion rate was 76.3%. At all these temperatures, the CH4 selectivity was 100%.

[0108] Example 10

[0109] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:1.4, wherein 0.743 g of nickel nitrate is weighed out. Immerse it onto 0.793 g of ZrO2 support and seal for 24 h.

[0110] 2) Place the product in a constant temperature drying oven at 70°C for 2 hours, and then dry it overnight at 110°C to obtain the dried product;

[0111] 3) After drying, the product was heated to 300℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0112] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in CO at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 15% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 19%.

[0113] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0114] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0115] At 250℃, the CO2 conversion rate was 58.4%; at 300℃, the CO2 conversion rate was 77.2%; and at 350℃, the CO2 conversion rate was 85.4%. At all these temperatures, the CH4 selectivity was 100%.

[0116] Example 11

[0117] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, and citric acid in a molar ratio of 1:0.4:4.2, with 0.743 g of nickel nitrate weighed out. Immerse it onto 0.793 g of ZrO2 support and seal for 24 h.

[0118] 2) Place the product in a constant temperature drying oven at 90°C for 10 hours, and then dry it overnight at 150°C to obtain the dried product;

[0119] 3) After drying, the product was heated to 300℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2.

[0120] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in 10% CO / N2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 15% Ni-CaZrO3 / ZrO2, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 19%.

[0121] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0122] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0123] At 250℃, the CO2 conversion rate was 57.5%; at 300℃, the CO2 conversion rate was 76.2%; and at 350℃, the CO2 conversion rate was 86.3%. At all these temperatures, the CH4 selectivity was 100%.

[0124] Example 12

[0125] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate, strontium nitrate, and citric acid in a molar ratio of 1:0.1:0.3:1.68, wherein 0.743 g of nickel nitrate is weighed out. Impregnate the solution onto 0.793 g of ZrO2 support and seal for 24 h.

[0126] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0127] 3) After drying, the product was calcined at 350℃ for 2 hours by increasing the temperature at 2℃ / min, and then calcined at 700℃ for 5 hours to obtain the catalyst precursor 15% NiO-Ca. 0.25 Sr 0.75 ZrO3 / ZrO2.

[0128] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain the catalyst 15% Ni-Ca. 0.25 Sr 0.75 ZrO3 / ZrO2, wherein the mass fraction of Ni is 15%, and Ca... 0.25 Sr 0.75 The ZrO3 mass fraction is 20%.

[0129] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 4:1.

[0130] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0131] At 250℃, the CO2 conversion rate was 56.8%; at 300℃, the CO2 conversion rate was 80.3%; and at 350℃, the CO2 conversion rate was 90.1%. At all these temperatures, the CH4 selectivity was 100%.

[0132] Example 13

[0133] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, strontium nitrate, and citric acid in a molar ratio of 1:0.3:0.1:1.68, wherein 0.743 g of nickel nitrate is weighed out. Immerse it onto 0.793 g of ZrO2 support and seal for 24 h.

[0134] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0135] 3) After drying, the product was calcined at 350℃ for 2 hours by increasing the temperature at 2℃ / min, and then calcined at 700℃ for 5 hours to obtain the catalyst precursor 15% NiO-Ca. 0.75 Sr 0.25 ZrO3 / ZrO2.

[0136] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain the catalyst 15% Ni-Ca. 0.75 Sr 0.25 ZrO3 / ZrO2, wherein the mass fraction of Ni is 15%, and Ca... 0.75 Sr 0.25 The ZrO3 mass fraction is 18%.

[0137] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 4:1.

[0138] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0139] At 250℃, the CO2 conversion rate was 58.8%; at 300℃, the CO2 conversion rate was 81.2%; and at 350℃, the CO2 conversion rate was 91.2%. At all these temperatures, the CH4 selectivity was 100%.

[0140] Example 14

[0141] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate and citric acid in a molar ratio of 1:0.125:1.35, wherein 0.743 g of nickel nitrate is weighed out. Impregnate it onto 0.793 g of ZrO2-SiO2 support and seal for 24 h.

[0142] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0143] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-CaZrO3 / ZrO2-SiO2.

[0144] 4) The obtained catalyst precursor was placed in a reactor and reduced at 450°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 15% Ni-CaZrO3 / ZrO2-SiO2, wherein the mass fraction of Ni was 15% and the mass fraction of CaZrO3 was 6%.

[0145] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0146] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0147] At 250℃, the CO2 conversion rate was 50.9%; at 300℃, the CO2 conversion rate was 87.6%; and at 350℃, the CO2 conversion rate was 91.1%. At all these temperatures, the CH4 selectivity was 100%.

[0148] Example 15

[0149] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, lanthanum nitrate, and citric acid in a molar ratio of 1:0.4:0.025:1.71, wherein 0.743 g of nickel nitrate is weighed out. Impregnate the solution onto 0.783 g of ZrO2 support and seal for 24 h.

[0150] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0151] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-La2O3-CaZrO3 / ZrO2.

[0152] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 15% Ni-La2O3-CaZrO3 / ZrO2, wherein the mass fraction of Ni was 15%, the mass fraction of CaZrO3 was 19%, and the mass fraction of La2O3 was 1%.

[0153] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0154] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0155] At 250℃, the CO2 conversion rate was 64.3%; at 300℃, the CO2 conversion rate was 81.7%; and at 350℃, the CO2 conversion rate was 88.5%. At all these temperatures, the CH4 selectivity was 100%.

[0156] Example 16

[0157] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, lanthanum nitrate, and citric acid in a molar ratio of 1:0.4:0.1:1.8, wherein 0.743 g of nickel nitrate is weighed out. Impregnate the solution onto 0.753 g of ZrO2 support and seal for 24 h.

[0158] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0159] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 700℃ and calcined for 5h to obtain the catalyst precursor 15% NiO-La2O3-CaZrO3 / ZrO2.

[0160] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 15% Ni-La2O3-CaZrO3 / ZrO2, wherein the mass fraction of Ni was 15%, the mass fraction of CaZrO3 was 19%, and the mass fraction of La2O3 was 4%.

[0161] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0162] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0163] At 250℃, the CO2 conversion rate was 65.2%; at 300℃, the CO2 conversion rate was 82.4%; and at 350℃, the CO2 conversion rate was 90.8%. At all these temperatures, the CH4 selectivity was 100%.

[0164] Example 17

[0165] 1) Prepare a mixed salt solution of nickel nitrate, calcium nitrate and citric acid in a molar ratio of 1:1.5:3, wherein 0.495 g of nickel nitrate is weighed out. Impregnate it onto 0.750 g of TiO2 support and seal for 24 h.

[0166] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0167] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 10% NiO-CaTiO3 / TiO2.

[0168] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 10% Ni-CaTiO3 / TiO2, wherein the mass fraction of Ni was 10% and the mass fraction of CaTiO3 was 28%. Figure 5 The XRD pattern showed characteristic peaks of CaTiO3, which proves the formation of CaTiO3 in the catalyst.

[0169] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0170] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0171] At 250℃, the CO2 conversion rate was 7.4%; at 300℃, the CO2 conversion rate was 50.1%; and at 350℃, the CO2 conversion rate was 75.6%. At all these temperatures, the CH4 selectivity was >99%.

[0172] Example 18

[0173] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, lanthanum nitrate, and citric acid in a molar ratio of 1:1.5:0.4:3.48, wherein 0.495 g of nickel nitrate is weighed out. Impregnate the solution onto 0.639 g of TiO2 support and seal for 24 h.

[0174] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0175] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 10% NiO-La2O3-CaTiO3 / TiO2.

[0176] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 10% Ni-La2O3-CaTiO3 / TiO2, wherein the mass fraction of Ni is 10%, the mass fraction of La2O3 is 10%, and the mass fraction of CaTiO3 is 28%. Figure 5 The XRD pattern showed characteristic peaks of CaTiO3, which proves the formation of CaTiO3 in the catalyst.

[0177] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0178] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0179] At 250℃, the CO2 conversion rate was 16.5%; at 300℃, the CO2 conversion rate was 69.5%; and at 350℃, the CO2 conversion rate was 82.2%. At all these temperatures, the CH4 selectivity was >99%.

[0180] Example 19

[0181] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, lanthanum nitrate, and citric acid in a molar ratio of 1:1.5:0.04:3.48, wherein 0.495 g of nickel nitrate is weighed out. Impregnate the solution onto 0.729 g of TiO2 support and seal for 24 h.

[0182] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0183] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 10% NiO-La2O3-CaTiO3 / TiO2.

[0184] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 10% Ni-La2O3-CaTiO3 / TiO2, wherein the mass fraction of Ni was 10%, the mass fraction of La2O3 was 1%, and the mass fraction of CaTiO3 was 28%.

[0185] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0186] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0187] At 250℃, the CO2 conversion rate was 10.7%; at 300℃, the CO2 conversion rate was 53.4%; and at 350℃, the CO2 conversion rate was 77.1%. At all these temperatures, the CH4 selectivity was >99%.

[0188] Example 20

[0189] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, cerium nitrate, and citric acid in a molar ratio of 1:1.5:0.4:3.48, where 0.495 g of nickel nitrate is weighed. Impregnate the solution onto 0.639 g of TiO2 support and seal for 24 h.

[0190] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0191] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 10% NiO-CeO2-CaTiO3 / TiO2.

[0192] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 10% Ni-CeO2-CaTiO3 / TiO2, wherein the mass fraction of Ni was 10%, the mass fraction of CeO2 was 12%, and the mass fraction of CaTiO3 was 28%.

[0193] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0194] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0195] At 250℃, the CO2 conversion rate was 14.1%; at 300℃, the CO2 conversion rate was 58.4%; and at 350℃, the CO2 conversion rate was 79.9%. At all these temperatures, the CH4 selectivity was >99%.

[0196] Example 22

[0197] 1) Prepare a mixed salt solution with nickel nitrate, calcium nitrate, lanthanum nitrate, and citric acid in a molar ratio of 1:1.5:0.4:3.48, wherein 0.495 g of nickel nitrate is weighed out. Impregnate the solution onto 0.639 g of TiO2-SiO2 support and seal for 24 h.

[0198] 2) Place the product in a constant temperature drying oven at 80℃ for 6 hours, and then dry it overnight at 120℃ to obtain the dried product;

[0199] 3) After drying, the product was heated to 350℃ at 2℃ / min and calcined for 2h, and then heated to 600℃ and calcined for 5h to obtain the catalyst precursor 10% NiO-La2O3-CaTiO3 / TiO2-SiO2.

[0200] 4) The obtained catalyst precursor was placed in a reactor and reduced at 550°C for 2 h in H2 at a flow rate of 30 mL / min and a heating rate of 2 °C / min to obtain a catalyst of 10% Ni-La2O3-CaTiO3 / TiO2-SiO2, wherein the mass fraction of Ni was 10%, the mass fraction of La2O3 was 10%, and the mass fraction of CaTiO3 was 28%.

[0201] 5) Under a pressure of 3 MPa, the contents are introduced into the reactor at a volumetric space velocity of 15000 mL / (g). cat h) A CO2 methanation test was performed by introducing CO2 and hydrogen in a molar ratio of 1:4.

[0202] Under the above conditions, the catalytic performance of the CO2 hydrogenation methanation reaction is as follows:

[0203] At 250℃, the CO2 conversion rate was 12.2%; at 300℃, the CO2 conversion rate was 52.2%; and at 350℃, the CO2 conversion rate was 72.7%. At all these temperatures, the CH4 selectivity was >99%.

[0204] All embodiments involved in this invention exhibit good catalytic performance in CO2 methanation reactions, and after long-term stability testing, the selectivity of the products remains stable without significant deactivation, demonstrating excellent stability and high application value.

[0205] The technical solutions disclosed and proposed in this invention can be implemented by those skilled in the art by appropriately modifying the conditions and routes, etc. Although the methods and preparation techniques of this invention have been described through preferred embodiments, those skilled in the art can obviously modify or recombine the methods and technical routes described herein without departing from the content, spirit, and scope of this invention to achieve the final preparation technique. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the spirit, scope, and content of this invention.

Claims

1. A perovskite oxide-modified supported Ni-based catalyst, characterized in that, The catalyst has a Ni-MO composition. x -ABO3 / support, where Ni is the active component of the catalyst, accounting for 5-20% of the catalyst's mass fraction; ABO3 has a perovskite structure, accounting for 6-40% of the catalyst's mass fraction; A is Ca, Sr, or a combination of Ca and Sr; when Ca and Sr are combined, the molar ratio Ca:Sr = 1:(0.01~99); B is Ti or Zr; the molar ratio A:B = 1:1; MO x As an auxiliary agent, its composition is La2O3 or CeO2, accounting for 0-12% of the catalyst by mass; the support is TiO2, ZrO2, TiO2-SiO2 or ZrO2-SiO2, accounting for 28-89% of the catalyst by mass. The preparation method of perovskite oxide-modified supported Ni-based catalysts includes the following steps: 1) Dissolve nickel nitrate, perovskite A-site corresponding metal nitrate, citric acid, and nitrate added as an auxiliary agent in distilled water to obtain a mixture, wherein the molar ratio of all nitrates to citric acid is 1:(1~3); immerse an equal volume of the dissolved solution on a carrier and seal it for 12~48h; 2) Unseal the carrier sealed in step 1), place it in a constant temperature drying oven at 50-90 ℃ for 2-10 hours, and then dry it overnight at 100-150 ℃ to obtain the dried product; 3) Calcine the dried product obtained in step 2) at 250-400ºC for 1-6 hours, and then continue to calcine at 550-900ºC for 3-10 hours to obtain the catalyst precursor; 4) Place the catalyst precursor obtained in step 3) in a reactor, introduce reducing gas into the reactor to reduce the catalyst precursor, and obtain catalyst Ni-ABO3 / support or Ni-MO. x -ABO3 / vector.

2. The method for preparing the perovskite oxide-modified supported Ni-based catalyst of claim 1, characterized in that... Includes the following steps: 5) Dissolve nickel nitrate, perovskite A-site corresponding metal nitrate, citric acid, and nitrate added as an auxiliary agent in distilled water to obtain a mixture, wherein the molar ratio of all nitrates to citric acid is 1:(1~3); immerse an equal volume of the dissolved solution on a carrier and seal it for 12~48h. 6) Unseal the carrier sealed in step 1), place it in a constant temperature drying oven at 50-90 ℃ for 2-10 hours, and then dry it overnight at 100-150 ℃ to obtain the dried product; 7) Calcine the dried product obtained in step 2) at 250-400ºC for 1-6 hours, and then continue to calcine at 550-900ºC for 3-10 hours to obtain the catalyst precursor; 8) Place the catalyst precursor obtained in step 3) in a reactor, introduce reducing gas into the reactor to reduce the catalyst precursor, and obtain catalyst Ni-ABO3 / support or Ni-MO. x -ABO3 / vector.

3. The preparation method according to claim 2, characterized in that: Step 1) The metal nitrate corresponding to the perovskite A site is one of calcium nitrate or strontium nitrate, or a mixture of calcium nitrate and strontium nitrate, in which the molar ratio of calcium nitrate to strontium nitrate is 1: (0.01~99).

4. The preparation method according to claim 2, characterized in that: Step 1) The nitrate added to the additive is lanthanum nitrate or cerium nitrate.

5. The preparation method according to claim 2, characterized in that: Step 3) The heating rate is 1 to 10 °C / min.

6. The preparation method according to claim 2, characterized in that: In step 4), the rate of introducing reducing gas is 10–30 mL / min, the reduction time is 1–3 h, the reduction temperature is 400–700 ℃, and the heating rate is 1–10 ℃ / min.

7. The preparation method according to claim 2, characterized in that: Step 4) The reducing gas is hydrogen or carbon monoxide; or a mixture of an inert gas and one or two of hydrogen or carbon monoxide; the volume percentage of the inert gas in the mixed gas atmosphere is 1%-99%.

8. The perovskite oxide-modified supported Ni-based catalyst of claim 1 is applied to the CO2 methanation reaction.

9. The perovskite oxide-modified supported Ni-based catalyst as described in claim 8 is applied to the CO2 methanation reaction; the catalyst is added to a fixed-bed reactor, and under conditions of a temperature of 200–600 °C and a pressure of 1–5 MPa, it is added to the reactor at a volume hourly space velocity of 3000–60000 mL / (g) cat h) Introduce carbon dioxide and hydrogen gas, wherein the molar ratio of carbon dioxide to hydrogen gas is 1:(1-5); to obtain the target product methane.

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