Low-temperature methane-dry-reforming carbon dioxide catalyst and preparation method thereof

Abstract

The application discloses a low-temperature methane-dry-reforming carbon dioxide catalyst and a preparation method thereof, and steps are as follows: a mixture solution is obtained by mixing a molecular sieve carrier, an organic alkali and a metal complex solution, then modification treatment is carried out to obtain a modified molecular sieve; the obtained modified molecular sieve is subjected to impregnation modification by using an alkaline earth metal and / or a rare earth metal to obtain a methane-dry-reforming carbon dioxide catalyst. The catalyst can carry out a methane-dry-reforming carbon dioxide reaction at a low temperature (≤600 DEG C), has a high methane and carbon dioxide conversion rate, the conversion rates are all more than 90%, and a molar ratio of reaction product synthesis gas CO / H2 is close to 1:1. Moreover, the catalyst preparation route is simple, the structure is stable, energy consumption is reduced, and the catalyst has certain industrial application potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resource utilization of carbon dioxide-rich natural gas, and particularly relates to a low-temperature methane-dry-reforming carbon dioxide catalyst and a preparation method thereof. BACKGROUND

[0002] The South China Sea has abundant geological resources of natural gas, accounting for 1 / 3 of the total oil and gas resources in China, equivalent to 12% of the global total, and the natural gas in the South China Sea is rich in 20-80% of carbon dioxide. As a major gas causing the greenhouse effect, how to resourcefully and rationally utilize carbon dioxide has become a global issue. Among numerous process routes, the methane-carbon dioxide dry reforming technology has a wide range of raw material sources and is a clean conversion route for effectively utilizing carbon dioxide and reducing carbon emissions from the source, and therefore has attracted much attention from the academic and industrial circles. The methane dry reforming (DRM) process is different from the methane steam reforming (SMR), and the production of steam is an energy-intensive process, and dry reforming does not require water, so the energy burden of steam production can be avoided; in addition to low energy consumption, dry reforming can also consume two greenhouse gases, CO2 and methane; compared with partial oxidation, dry reforming also has better cost-effectiveness. In addition, the n(H2) / n(CO) of the synthesis gas produced by the dry reforming method is approximately 1, while the n(H2) / n(CO) of the steam conversion is approximately 3, and the n(H2) / n(CO) of the partial oxidation is approximately 2, and the hydrogen-carbon ratio produced by the dry reforming process can be directly used as a raw material for low-carbon olefin carbonylation or hydroformylation, and is also suitable for the route of synthesis gas directly producing olefins (FTO), which makes up for the deficiency of the high hydrogen-carbon ratio of the synthesis gas in the methane steam reforming process. The dry reforming technology can not only be used for the conversion of natural gas, but also can be widely applied to shale gas, coal-bed gas, energy and chemical enterprise purge gas and coke oven gas, and is also suitable for the utilization of saturated gas in refining enterprises.

[0003] Although the methane-carbon dioxide dry reforming technology is highly valued, there are two major deficiencies in the reaction process: first, the dry reforming process usually has a reaction temperature of about 850℃, which has high energy consumption and high requirements for equipment materials, i.e., high investment, and affects long-period operation; second, the non-noble metal catalyst used for the reaction is prone to sintering and carbon deposition, which hinders its industrial application. Therefore, how to develop a low-temperature, high-efficiency and high-stability dry reforming technology is extremely important, which not only needs to overcome the technical bottleneck of the catalyst, but also needs to develop a new reaction process to reduce investment and energy consumption and realize long-period stable operation of the device. SUMMARY

[0004] The present application provides a low-temperature methane carbon dioxide dry reforming catalyst and a preparation method thereof to solve the problem of easy sintering and carbon deposition of existing catalysts in the methane-carbon dioxide dry reforming technology.

[0005] In a first aspect, the present application provides a preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, which is implemented by using the following technical scheme.

[0006] The preparation method of the low-temperature methane carbon dioxide dry reforming catalyst comprises the following steps.

[0007] S1. Mixing a molecular sieve carrier, an organic base and a metal complex solution to obtain a mixed solution, and then performing modification treatment to obtain a modified molecular sieve;

[0008] The organic base and the metal complex together serve as a template agent, and the amount of the template agent is controlled so that the molar ratio of the silicon source to the template agent in the reaction system is 1:(0.01-5); the metal complex solution is obtained by mixing a metal solution and a complexing agent, and the mass of the metal element introduced by the modification treatment is 0.5-20wt% of the mass of the molecular sieve carrier;

[0009] S2. Impregnating the modified molecular sieve obtained in step S1 with an alkaline earth metal and / or a rare earth metal to obtain a methane carbon dioxide dry reforming catalyst.

[0010] Further, in step S1, the preparation method of the molecular sieve carrier is as follows:

[0011] a. Mixing silica sol and eight-membered zeolite at a mass ratio of (5-40):(95-60) to obtain a slurry with a solid content of 5-80wt%;

[0012] b. Drying the slurry obtained in step a to obtain a molecular sieve carrier with D50≥90% and a molecular sieve purity of greater than 99%.

[0013] Further, the preparation method of the silica sol is as follows: mixing a silicon source dispersion liquid and an acid solution to make the pH value of the system be 1.5-6, and reacting for 1-5h to obtain silica sol; the silicon source dispersion liquid is obtained by mixing a silicon source and water at a molar ratio of 1:(0.05-5), and stirring for 0.5-2h at room temperature; the silicon source includes any one or a combination of several of tetraethyl orthosilicate, water glass or white carbon black; and the acid solution is 12% dilute sulfuric acid.

[0014] Further, the eight-membered zeolite includes SSZ-13 and / or SAPO-34.

[0015] Further, in step S1, the concentration of the organic base in the mixed solution is 0.05-10wt%, and the concentration of the organic base used is 0.01-5mol / L.

[0016] Further, in step S1, the organic base includes any one or a combination of at least two of n-butylamine, tetrapropylammonium hydroxide, tetrapropylammonium chloride, tetrapropylammonium bromide, adamantylamine, triethylamine, and morpholine.

[0017] Further, in step S1, the molar ratio of the metal solution to the complexing agent in the metal complex solution is 1:(1-5).

[0018] Further, the preparation method of the metal complex solution is: mixing a specified amount of metal solution with a complexing agent, and reacting at 30℃ for 3-6h.

[0019] Further, in step S1, the metal element in the metal solution includes any one or a combination of at least two of Zn, Ni, Co, Mo, or Cu.

[0020] Further, the metal solution is one or several of a nitrate, an acetate, a sulfate, a chloride, or an oxalate of the metal element.

[0021] Further, in step S1, the complexing agent includes any one or a combination of at least two of ethylenediamine, triethylamine, diethylenetriamine, cetyltrimethylammonium bromide, and polyvinylpyrrolidone.

[0022] Further, in step S1, the solid-liquid ratio of the molecular sieve carrier to the mixed solution containing the organic base and the metal complex is 1:10.

[0023] Further, in step S1, the modification treatment temperature is 90-180℃, and the time is 4-72h.

[0024] Further, in step S2, the alkaline earth metal includes any one or a combination of at least two of Mg, Ca, Sr, or Ba; and the rare earth metal includes Ce and / or La.

[0025] Further, in step S2, the metal loading is 0.5-20%.

[0026] Further, in step S2, the impregnation conditions are: impregnation at room temperature for 3-12h.

[0027] In a second aspect, the present application provides a low-temperature methane-dioxide carbon dry reforming catalyst, which is realized by the following technical scheme.

[0028] The low-temperature methane-dry-reforming carbon dioxide catalyst prepared by the preparation method has the following beneficial effects. -1 .

[0029] The application has the following beneficial effects.

[0030] The application has the following beneficial effects. DETAILED DESCRIPTION

[0031] The application is further described below in combination with examples.

[0032] The experimental methods used in the following preparation examples and examples are conventional methods unless otherwise specified; the materials, reagents, etc. used in the following preparation examples and examples are commercially available unless otherwise specified.

[0033] Example 1

[0034] A preparation method of a low-temperature methane-dry-reforming carbon dioxide catalyst, the steps are as follows:

[0035] (1) Preparation of special silicon sol for molding

[0036] At room temperature, take water glass as the silicon source, mix SiO2 and water in a molar ratio of 1:10, and stir for 2 h to make them uniformly mixed; drop the mixed solution into a 0.66 mol of 12% dilute sulfuric acid solution within 30 min, adjust the pH to 2.5, and react for 2 h to obtain the special silicon sol for molding.

[0037] (2) Preparation of SSZ-13 molecular sieve catalyst for molding

[0038] The prepared shaped silica sol is slurried with SSZ-13 at a mass ratio of SiO2 to raw zeolite of 20:80, the solid content of the catalyst is 15%, and then the slurry is added to a liquid tank of a spray forming device, and then the slurry is pumped into an atomizing chamber to be sprayed, dried by hot air, and formed into catalyst particles; finally, the microspherical catalyst is obtained by cyclone separation, and the average particle size is 70-80 μm. The shaped sample is placed in an oven at 110°C and dried overnight, and then the dried sample is placed in a muffle furnace, heated at a rate of 2°C / min from room temperature to 100°C, kept at 100°C for 60 minutes, then heated at a rate of 2°C / min from 100°C to 200°C, kept at 200°C for 60 minutes, then heated to 540°C according to the heating method, and then kept at 540°C for 6 hours, and then naturally cooled down, and the SSZ-13 zeolite catalyst can be taken out when the temperature is cooled down to room temperature.

[0039] (3) Preparation of high-zeolite-content Ni encapsulated SSZ-13 zeolite catalyst

[0040] The complexation reaction is carried out between nickel nitrate and ethylenediamine at a molar ratio of 1:1, the complexation temperature is 30°C, and the reaction time is 3h, and the obtained ethylenediamine complexed nickel ion solution has a mass fraction of 15% of Ni element, then adamantane amine solution is added thereto, the ethylenediamine complex and adamantane amine are used as co-template agents, 100mL of solution is prepared, so that the total template agent concentration in the mixed solution is 2.5wt%, and then 10g of the prepared shaped SSZ-13 zeolite catalyst is added to the above mixed solution, the solid-liquid ratio is 1:10, and hydrothermal reaction is carried out at 170°C for 24h; then the treated sample is washed with deionized water until it is neutral, and then transferred to an oven for drying at 110°C overnight, and then transferred to a muffle furnace, heated at a rate of 2°C / min from room temperature to 100°C, kept at 100°C for 60 minutes, then heated at a rate of 2°C / min from 100°C to 200°C, kept at 200°C for 60 minutes, then heated to 540°C according to the heating method, and then kept at 540°C for 6 hours, and then naturally cooled down, and the Ni@SSZ-13 binderless shaped catalyst can be taken out when the temperature is cooled down to room temperature.

[0041] (4) Preparation of “metal-alkaline” bifunctional catalyst

[0042] The Ni@SSZ-13 binderless shaped catalyst is immersed in an equal volume of a mixed solution of 2wt% calcium nitrate and 2wt% cerium nitrate at room temperature for 6h, dried and calcined, and finally a “metal-alkaline” bifunctional catalyst with Ni-CaO-CeO as the active center is obtained.

[0043] Example 2

[0044] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 1 in that: in the first step, a special silicon sol for molding is prepared, using tetraethyl orthosilicate as a silicon source, mixing SiO2 and water in a molar ratio of 1:10, stirring for 2 h to make them uniformly mixed, dropping the mixed solution into a 0.66 mol 12% dilute sulfuric acid solution within 30 min, adjusting the pH to 2.5, and reacting for 2 h to obtain a special silicon sol for molding.

[0045] Example 3

[0046] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 1 in that: in the second step, the prepared molding silicon sol is slurried with SSZ-13 at a SiO2 to raw molecular sieve powder mass ratio of 40:60, the solid content of the catalyst is 15%, the slurry is then added to a liquid tank of a spray molding device, and then the slurry is pumped into an atomization chamber to be sprayed, dried by hot air, and formed into catalyst particles; finally, cyclone separation is performed to obtain a microspherical catalyst with an average particle size of 70-80 μm. The molded sample is placed in an oven at 110°C and dried overnight, and then the dried sample is placed in a muffle furnace and calcined for 6 h according to the procedure of the second step, and the molded SSZ-13 molecular sieve catalyst is taken out when the temperature is reduced to room temperature.

[0047] Example 4

[0048] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 1 in that: in the second step, the prepared molding silicon sol is slurried with SAPO-34 at a SiO2 to raw molecular sieve powder mass ratio of 20:80, the solid content of the catalyst is 15%, the slurry is then added to a liquid tank of a spray molding device, and then the slurry is pumped into an atomization chamber to be sprayed, dried by hot air, and formed into catalyst particles; finally, cyclone separation is performed to obtain a microspherical catalyst with an average particle size of 70-80 μm. The molded sample is placed in an oven at 110°C and dried overnight, and then the dried sample is placed in a muffle furnace and calcined for 6 h according to the procedure of the second step, and the molded SAPO-34 molecular sieve catalyst is taken out when the temperature is reduced to room temperature.

[0049] In the third step, the nickel nitrate and ethylenediamine are complexed at a molar ratio of 1:1, the complexing temperature is 30°C, and the reaction time is 3h. The ethylenediamine complexed nickel ion solution obtained has a mass fraction of 15% of Ni element. The triethylamine solution is introduced, and the ethylenediamine complex and the triethylamine are used as the template agent together. A 100mL solution is prepared, and the total template agent concentration is 2.5wt%. The prepared shaped SAPO-34 molecular sieve catalyst is added to the above mixed solution in a solid-liquid ratio of 1:10, and hydrothermal reaction is performed at 170°C for 24h. Then, the treated sample is washed with deionized water until neutral, and then transferred to an oven for drying at 110°C overnight. The sample is transferred to a muffle furnace, and calcination is performed according to the procedure of the third step for 6h. When the temperature is reduced to room temperature, the Ni@SAPO-34 binderless shaped catalyst can be obtained.

[0050] Example 5

[0051] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, which is different from that of Example 1 in that in the third step, the metal active component is further introduced with Co on the basis of Ni. First, the nickel nitrate and the cobalt nitrate are added at a mass ratio of 1:1. The mixture is complexed with ethylenediamine at a molar ratio of 1:1, the total content of Ni and Co is 15%, the complexing temperature is 30°C, and the reaction time is 3h. The ethylenediamine complexed nickel-cobalt ion solution is obtained. Further, the adamantane amine solution is introduced, and the ethylenediamine complex and the adamantane amine are used as the template agent together. A 100mL solution is prepared, and the total template agent concentration is 2.5wt%. The prepared shaped SSZ-13 molecular sieve catalyst is added to the above mixed solution in a solid-liquid ratio of 1:10, and hydrothermal reaction is performed at 170°C for 24h. Then, the treated sample is washed with deionized water until neutral, and then transferred to an oven for drying at 110°C overnight. The sample is transferred to a muffle furnace, and calcination is performed according to the procedure of the third step for 6h. When the temperature is reduced to room temperature, the Ni-Co@SSZ-13 binderless shaped catalyst can be obtained.

[0052] Example 6

[0053] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 1 is that: in the third step, the complexation reaction of cobalt nitrate and ethylenediamine is carried out at a molar ratio of 1:1, the complexation temperature is 30°C, the reaction time is 3h, the obtained ethylenediamine complexed cobalt ion solution has a Co element mass fraction of 15%, then the adamantylamine solution is added thereto, the ethylenediamine complex and the adamantylamine are used as the template agent together, 100mL of solution is prepared, so that the total template agent concentration in the mixed solution is 2.5wt%, then 10g of the prepared shaped SSZ-13 molecular sieve catalyst is added to the above mixed solution, the solid-liquid ratio is 1:10, and the hydrothermal reaction is carried out at 170°C for 24h; then the treated sample is washed with deionized water until neutral, and then is transferred to an oven for drying at 110°C overnight, is transferred to a muffle furnace, and is calcined according to the procedure of the third step for 6h, and the Co@SSZ-13 binderless shaped catalyst can be obtained when the temperature is reduced to room temperature.

[0054] Example 7

[0055] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 4 is that: in the third step, the complexation reaction of nickel nitrate and ethylenediamine is carried out at a molar ratio of 1:1, the Ni content is 15%, the complexation temperature is 30°C, the reaction time is 3h, and the obtained ethylenediamine complexed nickel ion solution is further added with the triethylamine and morpholine solution, the triethylamine and morpholine are mixed at a molar ratio of 1:1, the ethylenediamine complex, the triethylamine and the morpholine are used as the template agent together, 100mL of solution is prepared, the total template agent concentration is 2.5wt%, then the prepared shaped SSZ-13 molecular sieve catalyst is added to the above mixed solution in a solid-liquid ratio of 1:10, and the hydrothermal reaction is carried out at 170°C for 24h; then the treated sample is washed with deionized water until neutral, and then is transferred to an oven for drying at 110°C overnight, is transferred to a muffle furnace, and is calcined according to the procedure of the third step for 6h, and the Ni@SAPO-34 binderless shaped catalyst can be obtained when the temperature is reduced to room temperature.

[0056] Example 8

[0057] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, different from example 1 is that: in the fourth step, the Ni@SSZ-13 binderless shaped catalyst is added to an equal volume of mixed solution of 2wt% magnesium nitrate solution and 2wt% cerium nitrate solution, is immersed at room temperature for 6h, is dried and calcined, and finally a “metal-alkali” bifunctional catalyst with a Ni-MgO-CeO active center is obtained.

[0058] Example 9

[0059] A preparation method of a low-temperature methane carbon dioxide dry reforming catalyst, which is different from example 1 in that: in the fourth step, the Ni@SSZ-13 binderless shaped catalyst is added into a mixed solution of 2wt% barium nitrate and 2wt% cerium nitrate for equal-volume impregnation, impregnated at room temperature for 6h, dried and calcined, and finally a "metal-alkali" bifunctional catalyst with Ni-BaO-CeO as the active center is obtained.

[0060] Comparative example 1:

[0061] A preparation method of a methane carbon dioxide dry reforming catalyst, the steps are as follows:

[0062] (1) At room temperature, mix SiO2 and water in a molar ratio of 1:10 with water glass as the silicon source, and stir for 2h to make them uniformly mixed; drop the mixed solution into a 0.66mol 12% dilute sulfuric acid solution within 30min, adjust the pH to 2.5, and react for 2h to obtain a special-shaped silica sol.

[0063] (2) Mix the prepared special-shaped silica sol with SSZ-13 at a SiO2 to original molecular sieve powder mass ratio of 20:80, and the solid content of the catalyst is 15%, then add the slurry into the liquid tank of the spray forming device, and then pump the slurry into the atomizing chamber for spraying, dry with hot air, form catalyst particles, and finally perform cyclone separation to obtain a microspherical catalyst with an average particle size of 70-80μm. Place the shaped sample in an oven at 110℃ and dry overnight, then place the dried sample in a muffle furnace, start heating from room temperature to 100℃ at a rate of 2℃ / min, keep at 100℃ for 60min, then start heating from 100℃ to 200℃ at a rate of 2℃ / min, keep at 200℃ for 60min, then follow the heating method to heat to 540℃, then keep at this temperature for 6h, and then start natural cooling, and when the temperature cools to room temperature, the shaped SSZ-13 molecular sieve catalyst can be taken out.

[0064] (3) Add the shaped SSZ-13 molecular sieve catalyst into a mixed solution of 10wt% nickel nitrate, 2wt% calcium nitrate and 2wt% cerium nitrate for equal-volume impregnation for 12h, then transfer to an oven at 110℃ and dry overnight, then transfer to a muffle furnace, start heating from room temperature to 100℃ at a rate of 2℃ / min, keep at 100℃ for 60min, then start heating from 100℃ to 200℃ at a rate of 2℃ / min, keep at 200℃ for 60min, then follow the heating method to heat to 540℃, then keep at this temperature for 6h, and then start natural cooling, and when the temperature cools to room temperature, the Ni-CaO-CeO / SSZ-13 catalyst can be taken out.

[0065] Catalyst performance evaluation

[0066] The 1 g catalyst prepared in Example 1-9 and Comparative Example 1 was mixed with quartz sand 5 mL and then loaded into the reaction tube of a 20 mL adiabatic micro fixed bed reactor. The two ends were filled with quartz sand and quartz wool. Nitrogen was continuously introduced during the programmed temperature rising process. The temperature was stabilized at 300 DEG C and 450 DEG C for 20 min, respectively. After the temperature was raised to 600 DEG C, the catalyst was activated for 30 min and then the reaction gas was introduced. The volume ratio of the raw materials methane and carbon dioxide was 1:1. Nitrogen was continuously introduced as the carrier gas. The feeding flow rate was 100 mL / min. The reaction pressure was 0.1 MPa. The reaction space velocity was 15000 h-1. -1 The reaction was analyzed 30 min after the reaction started to ensure that the reaction was stable. Then, the product was analyzed every 1 h using an online gas chromatograph. The experimental results are shown in Table 1.

[0067] Table 1: Experimental results of the catalytic performance of the catalysts under the same reaction conditions

[0068]

[0069] From the reaction results, under the same reaction conditions, the catalysts used in Examples 1-9 can achieve CH4 conversion and CO2 conversion of more than 90%, and the reaction performance is good. The catalyst used in Comparative Example 1 has poor reaction effect, with CH4 conversion of only 15% and CO2 conversion as low as 16%. Therefore, the "metal-alkaline" bifunctional binderless shaped catalyst prepared in Examples 1-9 has obvious reaction activity advantage.

[0070] The examples in the specific embodiments are preferred embodiments of the present application, and do not limit the protection scope of the present application. Therefore, equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A method for preparing a low-temperature methane-carbon dioxide dry reforming catalyst, characterized in that: Includes the following steps: S1. A mixture is prepared by mixing a molecular sieve support, an organic base, and a metal complex solution, and then modified to obtain a modified molecular sieve. In this system, an organic base and a metal complex are used together as template agents. The amount of template agent is controlled so that the molar ratio of silicon source to template agent in the reaction system is 1:(0.01~5). The metal complex solution is obtained by mixing a metal solution with a complexing agent. The mass of the metal element introduced during the modification treatment is 0.5-20 wt% of the mass of the molecular sieve support. The organic base includes any one or a combination of at least two of the following: n-butylamine, tetrapropylammonium hydroxide, tetrapropylammonium chloride, tetrapropylammonium bromide, adamantane, triethylamine, and morpholine; The metal element in the metal solution includes any one or a combination of at least two of Zn, Ni, Co, Mo or Cu; The complexing agent includes any one or a combination of at least two of ethylenediamine, triethylamine, diethylenetriamine, hexadecyltrimethylammonium bromide, and polyvinylpyrrolidone; The modification treatment temperature is 90-180℃, and the time is 4-72h; S2. The modified molecular sieve obtained in step S1 is impregnated with alkaline earth metals and rare earth metals to obtain a methane-carbon dioxide dry reforming catalyst. The alkaline earth metal includes any one or a combination of at least two of Mg, Ca, Sr or Ba; the rare earth metal includes Ce and / or La.

2. The method for preparing a low-temperature methane-carbon dioxide dry reforming catalyst according to claim 1, characterized in that: In step S1, the molecular sieve support is prepared as follows: Silica sol and SSZ-13 were slurried at a SiO2 to molecular sieve powder mass ratio of 20:80, with a solid content of 15%. The slurry was then added to the feed tank of a spray molding device and pumped into an atomization chamber for spraying. After hot air drying, catalyst particles were formed. Finally, cyclone separation was performed to obtain microsphere catalysts with an average particle size of 70-80 μm. The formed samples were placed in an oven at 110℃ and dried overnight. Then, the dried samples were placed in a muffle furnace and heated from room temperature to 100℃ at a rate of 2℃ / min, held at 100℃ for 60 minutes, and then heated from 100℃ to 200℃ at a rate of 2℃ / min, held at 200℃ for 60 minutes. The temperature was then increased to 540℃ using the same method and held at that temperature for 6 hours before being allowed to cool naturally. Once cooled to room temperature, the SSZ-13 molecular sieve catalyst was removed.

3. The method for preparing a low-temperature methane-carbon dioxide dry reforming catalyst according to claim 2, characterized in that: The method for preparing the silica sol is as follows: a silica source dispersion is mixed with an acid solution to make the pH of the system 1.5-6, and the reaction is carried out for 1-5 hours to obtain silica sol; the silica source dispersion is obtained by mixing a silica source and water in a molar ratio of 1:(0.05-5); the silica source includes any one or a combination of several of tetraethyl orthosilicate, water glass or silica.

4. A low-temperature methane-carbon dioxide dry reforming catalyst prepared by any one of the preparation methods described in claims 1-3.

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