Catalysts, methods for producing and using the same, and methods for methane-carbon dioxide reforming.

Abstract

This invention discloses a catalyst, its manufacturing method and use, and a method for methane-carbon dioxide reforming. The catalyst comprises an active matrix and CeO2, the active matrix comprising a La-Ni oxide having a perovskite structure. X-ray diffraction measurements show that the catalyst has diffraction peaks at 2θ positions of 32.7±0.3°, 31.3±0.3°, and 28.0±0.3°. Measurement by H2-TPR shows that the catalyst has at least one reduction peak below 400°C, and the CeO2 content is 1-20 wt% relative to the total amount of the catalyst. The catalyst has relatively high activity and stability, can effectively enhance CO2 adsorption during the reaction, can reduce CH4 adsorption and cracking, and has excellent carbon deposition resistance.

Description

Detailed description of the invention

[0001] [Cross-reference of related applications] This application claims the interests of Chinese patent application 202310636802.0, filed on 31 May 2023, the contents of which are incorporated herein by reference.

[0002] [Technical Field] This invention relates to the technical field of catalysts, and more specifically to catalysts, methods for producing and using the same, and methods for methane-carbon dioxide reforming reactions.

[0003] [Background technology] Methane and carbon dioxide are both greenhouse gases. The production of synthesis gas by methane-carbon dioxide reforming is an effective means of utilizing CO2 on a large scale, and synthesis gas (CO + H2) can be produced using relatively inexpensive natural gas, which can then be converted into other high-value downstream hydrocarbon products. However, the biggest challenge in this reaction process is that the catalysts used in the production of synthesis gas by methane-carbon dioxide reforming are mainly nickel-based catalysts, and these catalysts are prone to carbon deposition. If this carbon deposition problem cannot be effectively solved, it will seriously limit the stability of the catalyst and the industrialization process.

[0004] Perovskites have attracted attention in many fields due to their excellent conductivity, magnetism, thermoelectric properties, piezoelectricity, and other characteristics, as well as their low manufacturing cost and thermodynamic and mechanical stability even at high temperatures. Perovskite composite oxide materials are excellent conductors of oxygen ions and electrons under high-temperature conditions, can release oxygen even under inert conditions, and can replenish oxygen through the redox process. Therefore, using perovskite oxides as catalysts for methane-carbon dioxide reforming reactions is advantageous because it can effectively remove carbon deposits from the catalyst surface and improve the catalyst's ability to resist carbon deposition; however, the catalyst's activity and carbon deposition resistance are still not ideal.

[0005] CN113600200A discloses a method for producing a Ni-based alkaline earth metal modified catalyst for dry gas reforming of methane with carbon deposition resistance, which involves first producing an alkaline earth metal-doped LaAl perovskite support, and then supporting Ni on the support by an impregnation method. However, the stability of the catalyst is still not ideal. CN114588912A discloses a method for doping the A site of LaNiO3 perovskite with alkali metal K ions and then La x K 1-x The present invention discloses a method for producing a perovskite-type catalyst suitable for dry methane reforming, which involves forming NiO3 and then adding CeO2 solid powder, which has a stable structure and high oxygen capacity, based on it. CN114471581A discloses a carbon deposition-resistant catalyst for methane-carbon dioxide reforming, which involves supporting Ce on the surface of a perovskite oxide to obtain a Ce-supported ABO3-type perovskite oxide catalyst. Both of the above solutions utilize the oxygen storage properties of CeO2 to rapidly remove carbon deposits from the catalyst surface during the methane-carbon dioxide reforming reaction, but because the amount of CeO2 supported is high, it does not contribute to improving catalytic activity.

[0006] [Summary of the Invention] [Problems the invention aims to solve] The objective of the present invention is to provide a catalyst with excellent carbon deposition resistance, relatively high activity and stability, a method for producing and using the same, and a method for the methane-carbon dioxide reforming reaction, in order to solve the problems of conventional technologies, such as insufficient activity, poor stability and poor carbon deposition resistance of catalysts for methane-carbon dioxide reforming.

[0007] [Means for solving the problem] To achieve the above objective, a first aspect of the present invention provides a catalyst comprising an active matrix and CeO2, wherein the active matrix comprises a La-Ni oxide having a perovskite structure, and as measured by X-ray diffraction, the catalyst has diffraction peaks at 2θ positions of 32.7±0.3°, 31.3±0.3°, and 28.0±0.3°. Results measured by H2-TPR showed that the catalyst exhibits at least one reduction peak below 400°C. Based on the total amount of the catalyst, the CeO2 content is 1 to 20 wt%.

[0008] Preferably, the CeO2 content is 1 to 6 wt%, more preferably 2 to 4 wt%, based on the total amount of the catalyst.

[0009] A second aspect of the present invention is: Step (1) involves mixing a La source and a Ni source in the presence of a complexing agent to obtain a mixture, Step (2) involves reacting the mixture to form a gel, and then performing a first roasting to obtain a catalyst semi-product, The process includes (3) bringing a solution of a soluble compound containing Ce into contact with the catalyst semi-finished product in the presence of a surfactant, and then performing a second roasting. The present invention provides a method for producing a catalyst, wherein the surfactant includes polyoxyethylene-based nonionic surfactants and polyol-based nonionic surfactants.

[0010] A third aspect of the present invention provides the use of a catalyst described in the first aspect or a catalyst produced by the production method described in the second aspect in a methane-carbon dioxide reforming reaction.

[0011] A fourth aspect of the present invention provides a method for a methane-carbon dioxide reforming reaction, comprising contacting methane and carbon dioxide with a catalyst under reforming reaction conditions, wherein the catalyst is the catalyst described in the first aspect or a catalyst produced by the production method described in the second aspect.

[0012] [Effects of the invention] The catalyst provided in this invention has relatively high activity and stability, can effectively enhance CO2 adsorption during the reaction, can reduce CH4 adsorption and cracking, and has excellent carbon deposition resistance.

[0013] [Brief explanation of the drawing] [Figure 1] XRD spectra of the catalysts produced in Examples 1, 2, 3, and 4 of the present invention, as well as Comparative Examples 6 and 7. [Figure 2] Crystal phase analysis spectra of catalyst samples produced in Example 1 and Comparative Example 2 of the present invention. [Figure 3] H2-TPR curves of catalysts produced in Examples 1, 2, 3, 4, and 6 and Comparative Example 6 of the present invention. [Figure 4] This shows the H2-TPR curves of the catalysts produced in Example 1 and Comparative Example 8 of the present invention. [Figure 5] This shows the results of evaluating the stability of the catalysts produced in Examples 1 and 6 and Comparative Example 1 of the present invention. [Figure 6] This is a diagram showing the loss of heat after 100 hours of the catalytic reaction produced in Example 1, Example 6, and Comparative Example 6 of the present invention.

[0014] [Modes for carrying out the invention] The endpoints and any values ​​of the ranges disclosed herein should be understood to include values ​​close to those exact ranges or values, rather than being limited to those exact ranges or values. With respect to numerical ranges, one or more new numerical ranges can be obtained by combining the endpoint values ​​of each range, the endpoint values ​​of each range with individual dot values, and individual dot values, and these numerical ranges are deemed to be specifically disclosed herein.

[0015] A first aspect of the present invention provides a catalyst comprising an active matrix and CeO2, wherein the active matrix comprises a La-Ni oxide having a perovskite structure, and as measured by X-ray diffraction, the catalyst has diffraction peaks at 2θ positions of 32.7±0.3°, 31.3±0.3°, and 28.0±0.3°, and as measured by H2-TPR, the catalyst has at least one reduction peak below 400°C. Based on the total amount of the catalyst, the CeO2 content is 1 to 20 wt%.

[0016] In the present invention, the term "perovskite structure" has a broad definition and refers to a crystal structure identical or similar to that of perovskite CaTiO3. The "La-Ni-based oxide having a perovskite structure" refers to a compound containing Li, Ni, and O elements and having a crystal structure identical or similar to that of perovskite CaTiO3, and may include LaNiO3 and / or La2NiO4.

[0017] In the prior art, the research on perovskite catalysts has usually been limited to element doping and loading, and there has been no research on the special structure of perovskite composite oxide materials. The catalyst provided in the present invention has a special composite perovskite structure. As a result of measurement by X-ray diffraction (XRD), the catalyst has diffraction peaks at positions of 32.7 ± 0.3°, 31.3 ± 0.3°, and 28.0 ± 0.3°. According to the JCPDS standard card fitting analysis, the diffraction peak at the position where 2θ is 32.7 ± 0.3° belongs to the LaNiO3 species of the perovskite structure, the diffraction peak at the position where 2θ is 31.3 ± 0.3° belongs to the La2NiO4 species of the perovskite-like structure, and the diffraction peak at the position where 2θ is 28.0 ± 0.3° belongs to the CeO2 species.

[0018] In the present invention, the X-ray diffraction (XRD) test is carried out using a Cu Kα target line (incident wavelength 1.54056 Å), with a scan range of 0 to 90° and a scan speed of 10° / min, on an X'Pert3 Powder diffractometer.

[0019] In the present invention, the statement that "the catalyst has at least one reduction peak at a temperature of 400 °C or lower" means that the reduction temperature corresponding to the peak top of the reduction peak in the H2-TPR curve is 400 °C or lower. Similarly, all the following descriptions of "reduction temperature" refer to the temperature corresponding to the peak top of the reduction peak in the H2-TPR curve.

[0020] In the prior art, the Ni-based catalyst has a relatively high reduction temperature. The reported reduction temperature of the existing Ni-based perovskite composite oxides is usually 400°C or higher. In the present invention, as a result of measurement by H2-TPR, at least one reduction peak exists in the catalyst at 400°C or lower. Preferably, as a result of measurement by H2-TPR, at least one reduction peak exists in the catalyst at 350 - 390°C. More preferably, at least two reduction peaks exist in the catalyst at 350 - 390°C. For example, one reduction peak may exist at 350 - 370°C and one reduction peak may exist at 380 - 390°C.

[0021] In the present invention, the test conditions for H2-TPR include the following.

[0022] The reduction behavior of the catalyst is tested using a TP-5080 adsorption apparatus. First, 30 mg of the sample is filled into a quartz tube, N2 is introduced at a flow rate of 30 mL / min, the temperature is raised to 150°C at a rate of 10°C / min in a N2 atmosphere, held for 30 minutes, and then cooled to room temperature. The gas atmosphere is switched to 5 vol% H2 - 95 vol% N2, and the temperature is raised to 900°C at a heating rate of 10°C / min to obtain an H2-TPR curve. The tail gas is detected by TCD.

[0023] In the present invention, the catalyst has a relatively low reduction temperature, relatively high activity and stability. This is considered to be because CeO2 dispersed on the surface of the La-Ni-based oxide forms an interfacial effect. Due to the synergistic effect of CeO2, the unique spatial structure in which the LaNiO3 structure with an infinite perovskite layer and the La2NiO4 structure in which the rock salt layer and the perovskite layer are alternately stacked coexist is more advantageous for the reduction of Ni. Therefore, it is more advantageous to significantly lower the reduction temperature of the catalyst and further reduce the average particle size of the reduced Ni particles. In addition, the existence of this interfacial structure significantly improves the electron transfer ability and oxygen vacancy transport ability inside the catalyst during the reaction, enhances the suppression of the carbon deposition process of the catalyst and the conversion ability for the existing carbon deposits, thereby improving the activity and stability of the catalyst.

[0024] According to the present invention, preferably, the Ni element in the La-Ni oxide having a perovskite structure includes divalent nickel and trivalent nickel. Underlying this, the divalent nickel may be a Ni species with a La2NiO4 structure, and the trivalent nickel may be a Ni species with a LaNiO3 structure.

[0025] In a more preferred embodiment, as measured by X-ray diffraction, the catalyst has a ratio of S2 / S1 of (0.5 to 1.5):1, preferably (1.1 to 1.4):1, where S1 is the area of ​​a characteristic peak at 2θ = 32.7 ± 0.3° and S2 is the peak area of ​​the diffraction peak at 2θ = 31.3 ± 0.3°. In the above preferred case, the catalyst contains LaNiO3 and La2NiO4 species in appropriate ratios, which helps to further improve the activity and stability of the catalyst and enhance carbon deposition resistance.

[0026] In this invention, the peak area of ​​the diffraction peak in the XRD spectrum is measured by the Gaussian fitting integral method.

[0027] In a more preferred embodiment, the molar ratio of Ni to La in the catalyst, as determined by XPS, is (1.5 to 2.5):1, and may be typical and non-limiting molar ratios such as 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, or in a range between both, but preferably, the molar ratio of Ni to La in the catalyst, as determined by XPS, is (1.8 to 2.2):1.

[0028] In this invention, the valence state of elements and the elemental content on the surface are measured using XPS. XPS characterization is performed using an AXIS-ULTRADLD-line photoelectron spectrometer with a monochromatic Al-Kα target source, and is performed at a rate of 1 × 10⁻⁶ -8 Vacuum suction is performed under Pa conditions. To subtract charge effects, the C1s peak of contaminating carbon (binding energy 284.6 eV) is used as the calibration standard.

[0029] According to some preferred embodiments of the present invention, the average particle size of Ni particles measured by XRD of the catalyst reduced at 450°C for 2 hours in a hydrogen atmosphere is 13-22 nm, which may be a range of typical and non-limiting particle size values ​​such as 13 nm, 15 nm, 16 nm, 17 nm, 18 nm, 20 nm, 22 nm, or any two of these, but preferably the average particle size of Ni particles is 15-18 nm. In the prior art, the average particle size of Ni particles in Ni-based perovskite catalysts after reduction is typically 30-45 nm. The catalyst provided in the present invention has a smaller crystal grain size after reduction.

[0030] In this invention, the method for testing the average particle size of Ni particles is to determine the Ni particle size corresponding to 2θ = 44.5° by XRD characterization. 0 This involves measuring the crystal plane diffraction angles and full width at half maximum of the phase, and then measuring the crystal grain size of the active center using Scherrer's formula.

[0031] In conventional technology, the introduction of CeO2 into a catalyst is advantageous in promoting the removal of carbon deposits on the catalyst surface during the reaction, mainly by utilizing the oxygen storage properties of CeO2. However, achieving the above objective usually requires a relatively high CeO2 content of 10 wt% or more. On the other hand, in the present invention, CeO2 is introduced to form an interfacial effect, so it is not necessary to have an excessively high CeO2 content. According to the present invention, the CeO2 content is 1 to 20 wt% based on the total amount of the catalyst, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, or 20 wt%. Preferably, the CeO2 content is 1 to 6 wt%, preferably 2 to 4 wt%, based on the total amount of the catalyst. In the preferred case described above, it is advantageous for the CeO2 and the perovskite matrix to form the most interfaces. If the CeO2 content is too low, the contact area between the CeO2 and the perovskite matrix will be relatively small. On the other hand, if the amount of CeO2 is too high, the excess CeO2 will cover most of the surface of the perovskite matrix, resulting in reduced interface exposure and decreased activity.

[0032] The catalyst composition is analyzed by X-ray fluorescence spectroscopy (XRF, EAGLE III, EDAX). A total elemental scan of the catalyst is performed to analyze its elemental composition and the content of each element.

[0033] In a more preferred embodiment, characterization by XPS shows that the molar ratio of Ni to Ce in the catalyst is (1-20):1, for example, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 18:1, 20:1, and preferably (2-15):1.

[0034] According to a preferred embodiment of the present invention, the active matrix further comprises an auxiliary element, the auxiliary element being at least one selected from alkaline earth metals, preferably at least one selected from Mg, Ca, and Sr, and more preferably Mg. The above preferred case is advantageous for further improving the carbon deposition resistance and stability of the catalyst.

[0035] According to the present invention, preferably, the content of the auxiliary element in terms of oxides, based on the total mass of the active matrix, is 1 to 5 wt%, and may be, for example, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 4 wt%, 5 wt%, etc., but preferably 1.5 to 3 wt%.

[0036] According to a preferred embodiment of the present invention, the active matrix further comprises a molecular sieve. The regular pore structure of the molecular sieve, and the well-developed surface organic groups (e.g., hydroxyl) within the pores, interact with the perovskite, which is advantageous for further improving the carbon deposition resistance of the catalyst and for further limiting the average particle size of the Ni particles.

[0037] Preferably, the silicon dioxide content of the molecular sieve, based on the total mass of the active matrix, is 5 to 15 wt%, and may be, for example, 5 wt%, 8 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, etc., but preferably 9 to 11 wt%.

[0038] In this invention, the presence of the molecular sieve can be proven by crystalline phase analysis, and its content is determined by the XRF characterization method.

[0039] Crystalline phase analysis of the sample is performed using a Philips PW1710 model X-ray diffractometer with a Cu target, Kα source, tube voltage of 40kV, tube current of 30mA, scan step size of 0.02°, scan speed of 1.2° / min, and scan range 2θ=1~10°.

[0040] In a more preferred embodiment, the molecular sieve is a perfect Si mesoporous molecular sieve having a regular pore structure, preferably at least one of the MCM-41, SBA-15, MCM-48, and SBA-16 type molecular sieves, and more preferably an MCM-41 type molecular sieve.

[0041] In some particularly preferred embodiments of the present invention, the catalyst comprises an active matrix and CeO2, wherein the active matrix comprises a La-Ni oxide having a perovskite structure, auxiliary elements, and a molecular sieve, and as measured by X-ray diffraction, the catalyst has diffraction peaks at 2θ positions of 32.7±0.3°, 31.3±0.3°, and 28.0±0.3°.

[0042] Results measured by H2-TPR showed that the catalyst exhibits at least one reduction peak below 400°C. Based on the total amount of the catalyst, the CeO2 content is 1 to 20 wt%.

[0043] The selection range and content of the aforementioned auxiliary elements and molecular sieves are the same as those described above, and therefore will not be explained in detail here.

[0044] A second aspect of the present invention is: Step (1) involves mixing a La source, a Ni source, and a solvent in the presence of a complexing agent to obtain a mixture, Step (2) involves reacting the mixture to form a gel, and then performing a first roasting to obtain a catalyst semi-product, The process includes (3) bringing a solution of a soluble compound containing Ce into contact with the catalyst semi-finished product in the presence of a surfactant, and then performing a second roasting. The present invention provides a method for producing a catalyst, wherein the surfactant includes polyoxyethylene-based nonionic surfactants and polyol-based nonionic surfactants.

[0045] According to some preferred embodiments of the present invention, in step (1), the ratio of the molar amounts of the Ni source and the La source in terms of metallic elements is (0.5 to 2):1, preferably (0.5 to 1.5):1, for example, 0.5:1, 1:1, 1.5:1, etc.

[0046] Preferably, the molar ratio of the total molar amount of the La source and Ni source in terms of metallic elements to the complexing agent is 0.5 to 3:1, preferably 1 to 2:1.

[0047] In the present invention, the range of selection for the specific types of La and Ni sources is relatively broad, and all soluble organic or inorganic salts of metals can be applied to the present invention. For example, at least one selected from metal nitrates, acetates, and oxalates may be used.

[0048] Those skilled in the art know that the aforementioned La source and Ni source may further contain crystal water.

[0049] In the present invention, the range of selection for the complexing agent is relatively broad, and any complexing agent capable of complexing La sources and Ni sources in the field can be used in the present invention. Preferably, the complexing agent is selected from citric acid and / or ethylenediaminetetraacetic acid.

[0050] According to some preferred embodiments of the present invention, the mixing method may involve first dissolving the complexing agent in a solvent, and then mixing it with the La source and the Ni source. In step (1), the mixing may be carried out with stirring, but in the present invention, the specific conditions for stirring are not particularly limited, as long as each component is thoroughly mixed. Preferably, the mixing temperature is 50 to 100°C.

[0051] In the present invention, in step (1), the range of selection for the solvent is relatively broad, and preferably, the solvent is water. In the present invention, the amount of solvent used is not particularly limited, as long as it is sufficient to sufficiently disperse and mix each component.

[0052] According to a preferred embodiment of the present invention, in step (1), the mixture further comprises an auxiliary element precursor, the auxiliary element being at least one of alkaline earth metals, preferably at least one selected from Mg, Ca, and Sr, and more preferably Mg.

[0053] Preferably, the amount of the auxiliary element precursor used is such that the content of the auxiliary element in terms of oxide in the manufactured catalyst semi-finished product is 1 to 5 wt%, for example, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 4 wt%, 5 wt%, etc., but preferably 1.5 to 3 wt%.

[0054] According to some preferred embodiments of the present invention, the auxiliary element precursor may be an oxide of the auxiliary element or a substance that can optionally form an oxide thereof by roasting, for example, at least one of a nitrate, acetate, and oxalate containing the auxiliary element.

[0055] According to some preferred embodiments of the present invention, in step (1), the mixture further comprises a molecular sieve. The method of mixing involves first dissolving the complexing agent in a solvent, and then mixing it with the La source, the Ni source, an optional auxiliary element precursor, and an optional molecular sieve.

[0056] Preferably, the amount of molecular sieve used is such that the content of the molecular sieve in the manufactured catalyst semi-finished product, in terms of silicon dioxide, is 5 to 15 wt%, for example, 5 wt%, 8 wt%, 9 wt%, 9.5 wt%, 10 wt%, 10.5 wt%, 11 wt%, etc., but preferably it is 9 to 11 wt%.

[0057] The selection range of the molecular sieve is the same as in the first aspect of the present invention, and therefore will not be described in detail here.

[0058] Preferably, the average pore size of the molecular sieve is 1 to 15 nm, preferably 5 to 10 nm. Utilizing a molecular sieve with the above preferred pore structure is advantageous for precisely controlling the crystal grain size of the catalyst and preventing aggregation.

[0059] According to some preferred embodiments of the present invention, in step (2), the conditions for the reaction include a temperature of 50 to 100°C, preferably 60 to 90°C, and a time of 1 to 12 hours, preferably 6 to 8 hours.

[0060] Preferably, the conditions for the first roasting include a temperature of 300 to 1200°C, preferably 400 to 600°C, and a duration of 2 to 20 hours, preferably 4 to 8 hours. Optionally, drying may be included before the first roasting, and in the present invention, the drying conditions are not particularly limited, as long as the solvent can be removed. Preferably, the drying temperature is 80 to 120°C.

[0061] In this invention, the synergistic effect of the polyoxyethylene-based nonionic surfactant and the polyol-based nonionic surfactant is advantageous for forming an interfacial effect between CeO2 / La-Ni oxides, thereby lowering the reduction temperature of the catalyst and improving the activity and stability of the catalyst.

[0062] According to some preferred embodiments of the present invention, the polyoxyethylene-based nonionic surfactant is selected from polyethylene glycol and / or aliphatic alcohol polyoxyethylene ethers, preferably at least one of PEG200, PEG400, PEG600, AEO-7, AEO-8, and AEO-9, more preferably at least one of PEG200, PEG400, and PEG600, and even more preferably PEG400.

[0063] According to some preferred embodiments of the present invention, the polyol-based nonionic surfactant is a sorbitan fatty acid ester, preferably at least one of sorbitan monopalmitate (Span 40), sorbitan monooleate (Span 80), and sorbitan monostearate (Span 60), more preferably sorbitan monooleate (Span 80).

[0064] In a more preferred embodiment, the mass ratio of the polyoxyethylene-based nonionic surfactant to the polyol-based nonionic surfactant is 1:(0.1~1), and may be, for example, 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, or in a range between both, but preferably the mass ratio of the polyoxyethylene-based nonionic surfactant to the polyol-based nonionic surfactant is 1:(0.1~0.5), more preferably 1:(0.1~0.2). In the above preferred case, CeO2 is well dispersed on the catalyst surface, which is advantageous for optimizing the interfacial effect.

[0065] In the present invention, the objectives of the present invention can be achieved if it is ensured that the contact in step (3) is carried out in the presence of the surfactant. According to some preferred embodiments of the present invention, the ratio of the mass of the Ce-soluble compound in terms of CeO2 to the mass of the surfactant is 1:(1~10), and may be, for example, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, etc., but is preferably 1:(1~8). The above preferred case is advantageous for further improving the activity and stability of the catalyst.

[0066] In the present invention, the method for introducing the surfactant is not particularly limited. The surfactant may be introduced by preparing a solution with a Ce-soluble compound and then contacting the catalyst semi-finished product, or by contacting the catalyst semi-finished product with a solution of a Ce-containing soluble compound.

[0067] In the present invention, the range of selectable Ce soluble compounds is relatively broad, as long as they can provide Ce element, and preferably, the Ce soluble compound is at least one selected from cerium nitrate, cerium acetate, and cerium oxalate.

[0068] According to the present invention, the solvent in the solution of the Ce-containing soluble compound may be an organic solvent commonly used in the art, but is preferably at least one of alcohols, ketones, or hydrocarbons, preferably at least one selected from methanol, ethanol, acetone, and petroleum ether, and more preferably ethanol and / or methanol.

[0069] In the present invention, the amount of solvent used is not particularly limited, as long as it can dissolve the Ce-soluble compound. Preferably, the mass ratio of the Ce-soluble compound to the solvent in terms of oxide is 1:(1 to 50), and more preferably, 1:(10 to 30).

[0070] According to the present invention, preferably, the amount of the solution of the soluble compound containing Ce used is such that the CeO2 content in the produced catalyst is 1 to 20 wt%, for example, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, or 20 wt%. Preferably, the amount of the solution of the soluble compound containing Ce used is such that the CeO2 content in the produced catalyst is 1 to 6 wt%, more preferably 2 to 4 wt%.

[0071] In some preferred embodiments of the present invention, the second roasting conditions include a roasting temperature of 400 to 600°C and a holding time of 2 to 6 hours.

[0072] Preferably, the second roasting method includes first raising the temperature to 100-150°C at a heating rate of 3-6°C / min, for example, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, then raising the temperature to 200-250°C at a heating rate of 0.2-0.6°C / min, for example, 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, and then raising the temperature to the roasting temperature at a heating rate of 3-6°C / min and maintaining the temperature.

[0073] In the present invention, a second drying may be further included before the second roasting, the conditions for the second drying including a temperature of 80 to 120°C and a duration of 8 to 48 hours.

[0074] In the present invention, preferably, the product of the contact in step (3) is subjected to a second roasting directly (for example, if a second drying is further included, the second drying and second roasting are performed directly).

[0075] A third aspect of the present invention provides the use of a catalyst described in the first aspect or a catalyst produced by the production method described in the second aspect in a methane-carbon dioxide reforming reaction.

[0076] A fourth aspect of the present invention provides a method for a methane-carbon dioxide reforming reaction, comprising contacting methane and carbon dioxide with a catalyst under reforming reaction conditions, wherein the catalyst is the catalyst described in the first aspect or a catalyst produced by the production method described in the second aspect.

[0077] According to some preferred embodiments of the present invention, the conditions for the reforming reaction are as follows: the molar ratio of methane to carbon dioxide is 1:1 to 2, preferably 1:1.2 to 1.5; the reaction temperature is 700 to 950°C, preferably 750 to 850°C, more preferably 780 to 800°C; the pressure is 0.1 to 1 MPa, preferably 0.1 to 0.5 MPa, more preferably 0.2 to 0.4 MPa; and the total space velocity of the raw material gases is 10,000 to 30,000 h. -1 Preferably, 15,000 to 25,000 hours-1 More preferably, 18,000 to 22,000 hours -1 This includes being.

[0078] According to some preferred embodiments of the present invention, the method further includes reducing the catalyst in a hydrogen atmosphere prior to the contact.

[0079] Preferably, the reduction conditions include a temperature of 400 to 600°C, preferably 400 to 550°C, a duration of 1 to 20 hours, preferably 2 to 6 hours, and a pressure of 0.1 to 0.5 MPa, preferably 0.2 to 0.3 MPa.

[0080] The present invention will be described in detail below with reference to examples.

[0081] Unless otherwise noted, all raw materials used in the following examples are commercially available products.

[0082] The MCM-41 molecular sieves used in the following examples are perfect Si molecular sieves with an average pore size of 6 nm.

[0083] X-ray diffraction (XRD) testing is performed using an X' Pert3 Powder diffractometer with a Cu Kα target line (incident wavelength 1.54056 Å), a scan range of 0-90°, and a scan speed of 10° / min.

[0084] Crystalline phase analysis of the sample is performed using a Philips PW1710 model X-ray diffractometer with a Cu target, Kα source, tube voltage of 40kV, tube current of 30mA, scan step size of 0.02°, scan speed of 1.2° / min, and scan range 2θ=1~10°.

[0085] The H2-TPR test is carried out using a TP-5080 adsorption analyzer. First, 30 mg of the sample is filled into a quartz tube, N2 is introduced at a flow rate of 30 mL / min, heated to 150 °C at a rate of 10 °C / min in an N2 atmosphere, held for 30 minutes, and then cooled to room temperature. The gas atmosphere is switched to 5% H2-95% N2, and heated to 900 °C at a heating rate of 10 °C / min. The tail gas is detected by a TCD. The reduction rate of the sample is measured by the amount of hydrogen consumed in the in-situ reduction of CuO.

[0086] The composition of the catalyst is analyzed by X-ray fluorescence spectroscopy (XRF, EAGL EIII, manufactured by EDAX). By performing a full-element scan of the catalyst, the elemental composition of the catalyst and the content of each element are analyzed.

[0087] Method for testing the average particle size of Ni particles: After the catalyst is reduced at 450 °C for 2 hours in a hydrogen atmosphere, an XRD test is performed using a Cu Kα target line (incident wavelength 1.54056 Å) on an X’ Pert3 Powder diffractometer with a scan range of 0-90° and a scan speed of 10° / min. Next, the particle size is calculated using the Scherrer formula.

[0088] The amount of carbon deposition in the catalyst after the reaction is characterized by TGA. The thermal analysis is carried out using a thermogravimetric analyzer (SETSYS Evolution, manufactured by SETARAM) combined with a mass spectrometer (Hider, UK) manufactured by Perkin Elmer, USA. The heating rate is 10 °C·min -1 and the test is carried out in an air atmosphere with a gas flow rate of 30 mL·min -1 and the measurement temperature range is from room temperature to 900 °C.

[0089] Example 1 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min. A catalyst semi-finished product was obtained. The composition of the catalyst semi-finished product by XRF testing is shown in Table 1. Subsequently, 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-1 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) tests were performed on the above catalyst. The XRD spectrum shown in Figure 1 indicates that the catalyst has diffraction peaks at 2θ positions of 28.0°, 31.2°, and 32.7°. It was revealed that the catalyst has perovskite LaNiO3 and perovskite-like La2NiO4 structures, and that CeO2 is present. Crystal phase analysis of the sample shown in Figure 2 clearly revealed a characteristic peak for MCM-41, indicating the presence of MCM-41 molecules in the catalyst. H2-TPR tests were performed on the catalyst described above, and the results are shown in Figures 3 and 4. The catalyst exhibits two reduction peaks at 354°C and 385°C.

[0090] Example 2 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 158 g of La(NO3)3·6H2O and 106 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 1 g of MgO and 9 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 10g of ethanol, 1.9g of PEG200, and 0.3g of span60 were taken and mixed. 2g of Ce(NO3)3·6H2O was dissolved in the above mixture. Then, 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 120°C, and then roasted in a muffle oven. Muffle oven heating method: 50 ℃~120 Between 1°C and 220°C, the heating rate was 5°C / min; between 120°C and 220°C, it was 0.5°C / min; and between 220°C and 450°C, it was 5°C / min. Then, the catalyst CAT-2 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) tests were performed on the above catalyst. The XRD spectrum shown in Figure 1 indicates that the catalyst has diffraction peaks at 2θ positions of 28.1°, 31.4°, and 32.9°. It was revealed that the catalyst forms a perovskite LaNiO3 structure and a perovskite-like La2NiO4 structure, and that CeO2 is present. An H2-TPR test was performed on the catalyst described above, and the results are shown in Figure 3. The catalyst exhibits two reduction peaks at 354°C and 389°C.

[0091] Example 3 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 151.4 g of La(NO3)3·6H2O and 101.7 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 3 g of MgO and 11 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 100°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 129g of ethanol, 29.4g of AEO-8, and 5.8g of span40 were taken and mixed. 12.9g of Ce(NO3)3·6H2O was dissolved in the above mixture. Then, 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-3 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) tests were performed on the above catalyst. The XRD spectrum shown in Figure 1 indicates that the catalyst has diffraction peaks at 2θ positions of 28.0°, 31.3°, and 32.7°. It was revealed that the catalyst forms a perovskite LaNiO3 structure and a perovskite-like La2NiO4 structure, and that CeO2 is present. An H2-TPR test was performed on the catalyst described above, and the results are shown in Figure 3. The catalyst exhibits two reduction peaks at 366°C and 386°C.

[0092] Example 4 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 260g of ethanol, 65g of PEG400, and 6.5g of span80 were taken and mixed. 50.5g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-4 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) tests were performed on the above catalyst. The XRD spectrum shown in Figure 1 indicates that the catalyst has diffraction peaks at 2θ positions of 28.0°, 31.2°, and 32.7°. It was revealed that the catalyst forms a perovskite LaNiO3 structure and a perovskite-like La2NiO4 structure, and that CeO2 is present. An H2-TPR test was performed on the catalyst described above, and the results are shown in Figure 3. The catalyst exhibits one reduction peak at 390°C.

[0093] Example 5 70.3 g of citric acid was dissolved in 264 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 158.5 g of La(NO3)3·6H2O and 106.5 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 10 g of a commercially available MCM-41 molecular sieve was added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-5 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) testing of the above catalyst revealed that the XRD spectrum was similar to that of Example 1 in Figure 1. H2-TPR testing of the above catalyst revealed that the catalyst has one reduction peak at 355°C and another reduction peak at 386°C.

[0094] Example 6 76.5 g of citric acid was dissolved in 286.6 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 172.3 g of La(NO3)3·6H2O and 115.8 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of commercially available MgO was added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture. Then, 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-6 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) testing of the above catalyst revealed that the XRD spectrum is similar to that of Example 1 in Figure 1. H2-TPR testing of the above catalyst revealed that, as shown in Figure 3, the catalyst has two reduction peaks at 352°C and 382°C.

[0095] Example 7 78.1 g of citric acid was dissolved in 293 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 176 g of La(NO3)3·6H2O and 118.3 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 9 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst CAT-7 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) testing of the above catalyst revealed that the XRD spectrum is similar to that of Example 1 in Figure 1. H2-TPR testing of the above catalyst revealed that the catalyst has two reduction peaks at 356°C and 392°C.

[0096] Example 8 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was 5°C / min between 50°C and 450°C. Catalyst CAT-8 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 1. X-ray diffraction (XRD) tests performed on the above catalyst revealed that it has diffraction peaks at 2θ positions of 28.1°, 31.3°, and 32.8°. It was found that the catalyst contains perovskite LaNiO3 and perovskite-like La2NiO4 structures, and that CeO2 is present. H2-TPR testing of the above catalyst revealed that it exhibits a single reduction peak at 390°C.

[0097] Comparative Example 1 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. Catalyst DCAT-1 was obtained. The catalyst composition is shown in Table 2. H2-TPR tests were performed on the catalyst, and the results showed that the catalyst exhibited one reduction peak at 432°C and another reduction peak at 571°C.

[0098] Comparative Example 2 77.6 g of Ni(NO3)2·6H2O was dissolved in 192 g of water, and 80 g of a commercially available SiO2 support was impregnated for 8 hours. Then, it was dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst DCAT-2 was obtained by roasting at 450°C for 4 hours. H2-TPR testing of the above catalyst revealed that it exhibits a single reduction peak at 421°C. The catalyst composition is shown in Table 2. The crystal phase analysis spectra of the catalyst sample are shown in Figure 2.

[0099] Comparative Example 3 77.6 g of Ni(NO3)2·6H2O was dissolved in 192 g of water, and 80 g of a commercially available Al2O3 support was impregnated for 8 hours. Then, it was dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst DCAT-3 was obtained by roasting at 450°C for 4 hours. H2-TPR testing of the above catalyst revealed that it exhibits a single reduction peak at 431°C. The catalyst composition is shown in Table 2.

[0100] Comparative Example 4 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Co(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of a commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture. Then, 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst DCAT-4 was obtained by roasting at 450°C for 4 hours. H2-TPR testing of the above catalyst revealed that it exhibits a single reduction peak within the range of 410°C to 430°C. The catalyst composition is shown in Table 2.

[0101] Comparative Example 5 77.6 g of Ni(NO3)2·6H2O was dissolved in 192 g of water, and 80 g of commercially available MCM-41 support was impregnated for 8 hours. Then, it was dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of ethanol, 4g of PEG400, and 0.4g of span80 were taken and mixed. 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixture, and then 80g of the catalyst semi-finished solid was impregnated in the Ce(NO3)3·6H2O solution for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst DCAT-5 was obtained by roasting at 450°C for 4 hours. H2-TPR testing of the above catalyst revealed that it exhibits a single reduction peak at 425°C. The catalyst composition is shown in Table 2.

[0102] Comparative Example 6 78.1 g of citric acid was dissolved in 293 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 176 g of La(NO3)3·6H2O and 118.3 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 9 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. Catalyst DCAT-6 was obtained. The catalyst composition is shown in Table 2. X-ray diffraction (XRD) tests performed on the above catalyst revealed, as shown in Figure 1, that the catalyst's physical phase is mainly a perovskite LaNiO3 phase. H2-TPR testing of the above catalyst revealed that it exhibits three reduction peaks within the range of 400°C to 650°C.

[0103] Comparative Example 7 77.6 g of Ni(NO3)2·6H2O was dissolved in 192 g of water, and 80 g of a commercially available CeO2 support was impregnated for 8 hours. Then, it was dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. Catalyst DCAT-7 was obtained. The catalyst composition is shown in Table 2. X-ray diffraction (XRD) tests were performed on the above catalyst, and as shown in Figure 1, the catalyst's physical phase was mainly CeO2. H2-TPR testing of the above catalyst revealed that the catalyst exhibits two reduction peaks within the range of 410°C to 480°C.

[0104] Comparative Example 8 68.8 g of citric acid was dissolved in 258 mL of water and stirred at 80°C for 30 min to completely dissolve the citric acid. 155 g of La(NO3)3·6H2O and 104 g of Ni(NO3)2·6H2O were added to the aqueous solution of citric acid and stirred at 80°C for 1 hour. 2 g of MgO and 10 g of commercially available MCM-41 molecular sieve were added to the solution and stirred at 80°C for 8 hours to form a gel. The gel was then dried at 110°C and roasted at 650°C for 6 hours, with a heating rate of 5°C / min during roasting. A catalyst semi-finished solid was obtained. 40g of water was taken, and 8.4g of Ce(NO3)3·6H2O was dissolved in the above mixed solution. Then, 80g of the catalyst semi-finished solid was impregnated in the solution containing Ce(NO3)3·6H2O for 8 hours. After impregnation, it was dried directly in an oven at 100°C, and then roasted in a muffle oven. The heating method for the muffle oven was as follows: between 50°C and 120°C, the heating rate was 5°C / min; between 120°C and 220°C, the heating rate was 0.5°C / min; and between 220°C and 450°C, the heating rate was 5°C / min. Finally, the catalyst DCAT-8 was obtained by roasting at 450°C for 4 hours. The catalyst composition is shown in Table 2. X-ray diffraction (XRD) analysis was performed on the above catalyst, and no characteristic peaks for La2NiO4 were observed. As a result of H2-TPR testing on the above catalyst, it became clear that a large number of nickel species that have been reduced at high temperatures exist above 400°C, as shown in Figure 4.

[0105] [Table 1] Note: In the table above, the CeO2 content is based on the total amount of catalyst, while the content of auxiliary elements and molecular sieves is based on the mass of the catalyst semi-finished product.

[0106] [Table 2] Note: In the table above, the CeO2 content is based on the total amount of catalyst, while the content of auxiliary elements and molecular sieves is based on the mass of the catalyst semi-finished product.

[0107] Test example The catalyst-mediated methane-carbon dioxide reforming reaction in the above examples and comparative examples was evaluated. First, the catalyst described above was reduced at 450°C and a hydrogen pressure of 0.3 MPa for 4 hours, and then the methane-carbon dioxide reforming reaction was carried out. The reaction conditions were: a molar ratio of methane to carbon dioxide of 1:1.2, a reaction temperature of 800°C, a pressure of 0.3 MPa, and a total space velocity of 20,000 hF for the raw material gases. -1 This includes the following. After 96 hours of reaction, the product was collected, its composition was analyzed by gas chromatography, and the CO2 conversion rate and CH4 conversion rate were calculated. The amount of carbon deposit on the catalyst was tested by the loss on heat method in an air atmosphere. The results are shown in Table 3.

number

[0108] [Table 3]

[0109] As can be seen from the results in Table 3, the catalysts produced using the examples provided in this invention exhibit high CO2 conversion rates and CH4 conversion rates even after 96 hours of reaction, and have low carbon deposition. Figure 6 shows the thermal loss in an oxygen atmosphere after 100 hours of reaction for the catalysts of Examples 1 and 6 and Comparative Example 6. The catalysts provided in this invention were found to have strong carbon deposition resistance and good stability.

[0110] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, several simple modifications can be made to the technical solution of the present invention, including combining each technical feature in any other suitable manner, and these simple modifications and combinations should also be considered as part of the disclosure of the present invention and all fall within the scope of protection of the present invention. [Brief explanation of the drawing]

[0111] [Figure 1] These are the XRD spectra of the catalysts produced in Examples 1, 2, 3, and 4 of the present invention, as well as Comparative Examples 6 and 7. [Figure 2] These are the crystal phase analysis spectra of the catalyst samples produced in Example 1 and Comparative Example 2 of the present invention. [Figure 3] These are the H2-TPR curves of the catalysts produced in Examples 1, 2, 3, 4, and 6 of the present invention and Comparative Example 6. [Figure 4] These are the H2-TPR curves of the catalysts produced in Example 1 and Comparative Example 8 of the present invention. [Figure 5] These are the results of evaluating the stability of the catalysts produced in Examples 1 and 6 and Comparative Example 1 of the present invention. [Figure 6] This is a diagram showing the loss of heat after 100 hours of the catalytic reaction produced in Example 1, Example 6, and Comparative Example 6 of the present invention.

Claims

1. A catalyst comprising an active matrix and CeO ２ The active matrix comprises a La-Ni oxide having a perovskite structure, and as measured by X-ray diffraction, the catalyst has diffraction peaks at 2θ positions of 32.7±0.3°, 31.3±0.3°, and 28.0±0.3°. H ２ - As measured by TPR, the catalyst exhibits at least one reduction peak below 400°C. Based on the total amount of the catalyst, the CeO ２ A catalyst characterized by having a content of 1 to 20 wt%.

2. The catalyst, reduced in a hydrogen atmosphere at 450°C for 2 hours, had an average particle size of Ni particles measured by X-ray diffraction of 13 to 22 nm, preferably 15 to 18 nm. Preferably, H ２ -Measurements by TPR showed that the catalyst exhibited at least one reduction peak between 350 and 390°C. Preferably, the catalyst has at least two reduction peaks at 350 to 390°C, as described in claim 1.

3. Based on the total amount of the catalyst, the CeO ２ The content is 1 to 6 wt%, preferably 2 to 4 wt%, Preferably, the catalyst according to claim 1 or 2, characterized by XPS, the molar ratio of Ni element to Ce element in the catalyst is (1 to 20):1, preferably (2 to 15):

1.

4. The Ni element in the La-Ni oxide having the perovskite structure includes divalent nickel and trivalent nickel. Preferably, the catalyst according to any one of claims 1 to 3, wherein, as measured by X-ray diffraction, the catalyst has a characteristic peak area at a position where 2θ is 32.7 ± 0.3°, where S1 is the area of ​​the diffraction peak at a position where 2θ is 31.3 ± 0.3°, and S2 is the peak area of ​​the diffraction peak, and S2 / S1 is (0.5 to 1.5):1, preferably (1.1 to 1.4):

1.

5. The catalyst according to any one of claims 1 to 4, wherein, as a result of characterization by XPS, the molar ratio of Ni element to La element in the catalyst is (1.5 to 2.5):1, preferably (1.8 to 2.2):

1.

6. The active matrix further comprises an auxiliary element, the auxiliary element being at least one selected from alkaline earth metals, preferably at least one selected from Mg, Ca, and Sr, and more preferably Mg. Preferably, the content of the auxiliary element in terms of oxides, based on the total mass of the active matrix, is 1 to 5 wt%, preferably 1.5 to 3 wt%, according to claim 5.

7. The catalyst according to any one of claims 1 to 6, further comprising a molecular sieve.

8. The catalyst according to claim 7, wherein the content of the molecular sieve, in terms of silicon dioxide, is 5 to 15 wt%, preferably 9 to 11 wt%, based on the total mass of the active matrix.

9. The catalyst according to claim 7 or 8, wherein the molecular sieve is a perfect Si mesoporous molecular sieve, preferably at least one of MCM-41, SBA-15, MCM-48, and SBA-16 type molecular sieves, more preferably an MCM-41 type molecular sieve.

10. A method for manufacturing a catalyst, Step (1) involves mixing a La source, a Ni source, and a solvent in the presence of a complexing agent to obtain a mixture, Step (2) involves reacting the mixture to form a gel, and then performing a first roasting to obtain a catalyst semi-product, The process includes the step (3) of contacting a solution of a soluble compound containing Ce with the catalyst semi-finished product in the presence of a surfactant, and then performing a second roasting. A method for producing a catalyst, characterized in that the surfactant includes a polyoxyethylene-based nonionic surfactant and a polyol-based nonionic surfactant.

11. In step (1), the ratio of the molar amounts of the Ni source and the La source in terms of metallic elements is (0.5 to 2):1, preferably (0.5 to 1.5):

1. Preferably, the manufacturing method according to claim 10, wherein the molar ratio of the total molar amount of the La source and Ni source in terms of metal elements to the complexing agent is 0.5 to 3:

1.

12. The mixture further comprises an auxiliary element precursor, the auxiliary element being at least one of the alkaline earth metals, preferably at least one selected from Mg, Ca, and Sr, and more preferably Mg. Preferably, the amount of the auxiliary element precursor used is such that the content of the auxiliary element in terms of oxides in the manufactured catalyst semi-finished product is 1 to 5 wt%, preferably 1.5 to 3 wt%, the manufacturing method according to claim 11.

13. In step (2), the reaction conditions include a temperature of 50 to 100°C, preferably 60 to 90°C, and a time of 1 to 12 hours, preferably 6 to 8 hours. Preferably, the manufacturing method according to any one of claims 10 to 12, wherein the conditions for the first roasting include a temperature of 300 to 1200°C and a time of 2 to 20 hours.

14. The polyoxyethylene-based nonionic surfactant is selected from polyethylene glycol and / or aliphatic alcohol polyoxyethylene ethers, and is preferably at least one of PEG200, PEG400, PEG600, AEO-7, AEO-8, and AEO-9. Preferably, the polyol-based nonionic surfactant is a sorbitan fatty acid ester, preferably at least one of sorbitan monopalmitate, sorbitan monooleate, and sorbitan monostearate. Preferably, the mass ratio of the polyoxyethylene-based nonionic surfactant to the polyol-based nonionic surfactant is 1:(0.1 to 1), preferably 1:(0.1 to 0.5), the manufacturing method according to any one of claims 10 to 13.

15. CEO ２ The ratio of the mass of the Ce-soluble compound to the mass of the surfactant in the conversion is 1:(1 to 10), preferably 1:(1 to 8). Preferably, the amount of the solution of the soluble compound containing Ce used in the manufactured catalyst is such that CeO ２ The manufacturing method according to any one of claims 10 to 14, wherein the content of is 1 to 20 wt%, preferably 1 to 6 wt%, and more preferably 2 to 4 wt%.

16. The second roasting conditions include a roasting temperature of 400 to 600°C and a holding time of 2 to 6 hours. Preferably, the second roasting method includes first raising the temperature to 100 to 150°C at a heating rate of 3 to 6°C / min, then raising the temperature to 200 to 250°C at a heating rate of 0.2 to 0.6°C / min, and then raising the temperature to the roasting temperature at a heating rate of 3 to 6°C / min and maintaining the temperature, as described in any one of claims 10 to 15.

17. In step (1), the mixture further comprises a molecular sieve, Preferably, the amount of molecular sieve used is such that the content of the molecular sieve in the manufactured catalyst semi-finished product is 5 to 15 wt%, preferably 9 to 11 wt%, according to any one of claims 10 to 16.

18. The molecular sieve is a complete Si mesoporous molecular sieve, preferably at least one selected from MCM-41, SBA-15, MCM-48, and SBA-16 type molecular sieves, more preferably an MCM-41 type molecular sieve. Preferably, the average pore size of the molecular sieve is 1 to 15 nm, according to the manufacturing method of claim 17.

19. Use of a catalyst according to any one of claims 1 to 9 or a catalyst produced by a manufacturing method according to any one of claims 10 to 18 in a methane-carbon dioxide reforming reaction.

20. A method for a methane-carbon dioxide reforming reaction, comprising contacting methane and carbon dioxide with a catalyst under reforming reaction conditions, wherein the catalyst is the catalyst described in any one of claims 1 to 9 or a catalyst produced by the manufacturing method described in any one of claims 10 to 18.

21. The conditions of the reforming reaction are as follows: the molar ratio of methane to carbon dioxide is 1:1 to 2, preferably 1:1.2 to 1.5; the reaction temperature is 700 to 950 °C, preferably 750 to 850 °C, more preferably 780 to 800 °C; the pressure is 0.1 to 1 MPa, preferably 0.1 to 0.5 MPa, more preferably 0.2 to 0.4 MPa; and the total space velocity of the raw material gas is 10,000 to 30,000 h －１ , preferably 15,000 to 25,000 h －１ , more preferably 18,000 to 22,000 h －１ The method according to claim 20, comprising being such.

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