Reforming catalysts, methods of making and using the same, and methods of dry reforming of methane and carbon dioxide to produce syngas

Abstract

The present application provides a kind of reforming catalyst and its preparation method and application and the method for preparing synthesis gas by dry reforming of methane carbon dioxide, the catalyst contains high specific surface carrier MgAl2O4 And active metal component supported on the carrier, the active metal element contains first metal element, second metal element and third metal element, the first metal element is Ni, second metal element is Bi, and third metal element is one or more of Co, Ru and Ag, the specific surface area of the carrier MgAl2O4 It is above 120m 2 / g. The catalyst of the present application has the advantages of good thermal stability, high activity and stable carbon deposition resistance under high pressure. It does not react with the carrier under high temperature and high pressure conditions, can maintain small alloy grain size, and does not involve pore problems. Under the reaction conditions, the catalyst can ensure uniform dispersion of the active component on the carrier, small particle size, and is not easy to sinter and agglomerate.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and specifically relates to a reforming catalyst, its preparation method and application, as well as a method for preparing syngas by dry reforming methane and carbon dioxide. Background Technology

[0002] Methane dry reforming can simultaneously and efficiently utilize two greenhouse gases to produce syngas, providing basic feedstocks for Fischer-Tropsch synthesis and methanol synthesis, and is an important new green chemical process. This reaction is endothermic, and to reduce carbon buildup, the reaction temperature is generally chosen above 700℃; considering industrial economics, high pressure is selected for the reaction. However, methane dry reforming catalysts used under high pressure are prone to carbon buildup and sintering, affecting long-term stability and industrial application. Currently, most existing catalysts can achieve reaction stability under normal pressure; the catalytic stability of catalysts under high pressure is often a technical bottleneck. Furthermore, it is worth noting that the dry reforming of methane differs significantly from the steam reforming of methane in terms of reaction mechanism, thermodynamics, and kinetics (RGDing, ZFYan, LHSong, XMLiu, J.Nat.Gas Chem., 2001, 10, 237-255; Li Chunyi, Shen Shikong, Journal of China University of Petroleum, 2000, 24, 113-117; JGZhang, H.Wang, and AKDalai, Ind.Eng.Chem.Res. 2009, 48, 677-684). Catalysts suitable for steam reforming of methane may not be suitable for dry reforming of methane. Therefore, it is necessary to design and prepare suitable catalysts based on the characteristics and challenges of the reaction.

[0003] Methane-activating agents include noble metals (Rh, Ru, Pt, Pd, Ir) and transition metals (Ni, Co). Noble metals exhibit excellent activity in methane dry reforming reactions and good resistance to carbon deposition, but they are very expensive. Ni-based catalysts are widely used due to their excellent activity and low cost; however, Ni-based catalysts are prone to carbon deposition and deactivation. Therefore, promoters or suitable supports can be added to improve catalyst performance. Commonly used promoters include S, Sn, Au, Ag, K, and Mn, which passivate active sites and slow down the rate of carbon deposition. Promoters such as Fe, Co, Ru, Pt, and Rh increase oxygen coverage and accelerate carbon oxidation. Commonly used supports include MgO, Al2O3, and SiO2.For example: WO175755 A1 uses MgO as a support and loads Ni, Mg, and Fe for methane dry reforming under conditions of 0-5 bar and 500-1000℃; CN106607032A uses δ-Al2O3 as a support and loads a metal active component for methane dry reforming; CN106512999 A provides a catalyst for methane dry reforming with SiO2 as the support and loading Ni, Co, or Mg; CN103586030 A discloses a method for preparing a mesoporous confined nickel-based methane dry reforming catalyst; CN109759074 A discloses a catalyst for carbon dioxide dry reforming with γ-Al2O3 as the support and loading the active component nickel and the promoter yttrium oxide; CN101773835 A uses SiO2 as the support and Ni and La as the active components to prepare a Ni-La / SiO2 catalyst using a co-impregnation method; CN104475098 CN105381818 discloses a catalyst using CeO2 as a promoter and Rh-supported silica for the partial oxidation of methane to syngas; CN103055868 discloses a catalyst with highly dispersed Ni supported on mesoporous SBA-15 silica for the reforming of methane to carbon dioxide to syngas. CN103055913B discloses a nickel-based catalyst supported on mesoporous silica and its preparation method; CN105964261A discloses a method for preparing a Ni-based catalyst for dry reforming of methane that resists carbon deposition and sintering, using mesoporous silica-based material as a support, and forming a stable silica layer by adding a basic complexing agent nickel complex and silanol groups on the surface of the silica-based material to confine nickel particles; CN107552054A relates to a core-shell structured nickel-based catalyst for dry reforming of methane and its preparation method; CN107008328A provides a high-loading catalyst for triple reforming of methane and its preparation method, which contains a nickel-cobalt alloy, Al2O3 and SiO2; CN109967081A discloses a catalyst and its preparation method, which uses a precipitation method to obtain a stable gel with a nanosheet structure, and then performs in-situ encapsulation of a second component; however, generally, although these catalysts can achieve stable operation for a relatively short time under normal pressure conditions. However, under harsh high-pressure conditions, it cannot operate stably for extended periods, easily generating large amounts of carbon deposits or agglomeration, leading to catalyst deactivation. The formation of high-mechanical-strength, whisker-like carbon deposits can also cause catalyst pulverization and increased bed pressure drop. High-pressure conditions not only thermodynamically favor carbon deposit formation, but also, since the carbon deposition rate is proportional to the methane partial pressure, increased pressure inevitably accelerates carbon deposition kinetically. Furthermore, under high-pressure conditions, to improve conversion, the reaction temperature needs to be increased simultaneously. At high temperature and high pressure, gas-phase methane cracking can also form carbon deposit precursors, promoting the carbon deposition reaction on the catalyst.Therefore, high-pressure reaction conditions pose new challenges to the catalyst's resistance to carbon deposition and high-temperature stability, which is the main difficulty faced by methane dry reforming. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to solve the stability problem of reforming catalysts in the prior art, such as the stability problem in the high temperature and high pressure reaction environment of methane and carbon dioxide dry reforming, and to provide a reforming catalyst with good stability and high activity.

[0005] According to a first aspect of the present invention, a reforming catalyst is provided, the catalyst comprising a support MgAl2O4 and an active metal component supported on the support, the active metal comprising a first metal element, a second metal element, and a third metal element, wherein the first metal element is Ni, the second metal element is Bi, and the third metal element is one or more selected from Co, Ru, and Ag, and the specific surface area of ​​the support MgAl2O4 is 120 m². 2 / g or more.

[0006] According to a second aspect of the present invention, the present invention provides a method for preparing the catalyst of the present invention, wherein the method comprises: impregnating and contacting a source solution containing an active metal component in a specified ratio with a support MgAl2O4, drying by rotary evaporation to obtain a solid, and then subjecting it to calcination, reduction, and passivation.

[0007] According to a third aspect of the present invention, the present invention provides the application of the catalyst described herein in the production of syngas from methane through dry reforming, combined reforming, or triple reforming.

[0008] According to a fourth aspect of the present invention, the present invention provides a method for preparing syngas by dry reforming methane with carbon dioxide, wherein methane and carbon dioxide are contacted in the presence of the reforming catalyst described in the present invention; preferably, the contact conditions include: the flow rates of methane and carbon dioxide are each 30-70 ml / min; the pressure is 0.5-4.0 MPa; and the temperature is 600-1100 °C.

[0009] The catalyst of the present invention has a concentration greater than 120m 2 Using MgAl2O4 with a specific surface area of ​​ / g as a support, combined with the active components of this invention, it has the advantages of good thermal stability and high activity. No support reaction occurs under high temperature and high pressure conditions, and pore structure issues are not involved. During the reaction, the catalyst ensures uniform dispersion of the active components on the support, preventing agglomeration.

[0010] In summary, the catalyst of this invention has a simple preparation process, high reforming activity, and good stability. Even after 150 hours of stable operation under high temperature and high pressure conditions during methane dry reforming, it remains stable with almost no carbon buildup, completely solving the problem of carbon buildup and deactivation in methane dry reforming under high pressure. The method of this invention can be applied to industrial syngas production technology.

[0011] The catalyst of the present invention can be used in the reaction technology of dry reforming of methane and carbon dioxide to produce syngas, and can also be used as a catalyst for methane combined reforming or triple reforming. Attached Figure Description

[0012] Figure 1 The image shows the XRD pattern of the fresh catalyst in Example 1 of this invention.

[0013] Figure 2 The image shows the XRD pattern of the catalyst in Example 1 after 150 h of methane-CO2 reforming catalysis.

[0014] Figure 3 The image shows the XRD pattern of the catalyst in Comparative Example 1 after 150 h of methane-CO2 reforming catalysis.

[0015] Figure 4 The TG results are for the catalysts of Example 1 and Comparative Examples 1, 2, and 3 after catalytic reaction of methane CO2 reforming for 150 h.

[0016] Figure 5 The performance curve of the catalyst in Example 1 during the methane-CO2 reforming catalytic reaction after 150 h is shown.

[0017] Figure 6 The performance curve of the catalyst in Comparative Example 1 during the methane-CO2 reforming catalytic reaction after 150 h is shown. Detailed Implementation

[0018] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0019] This invention provides a reforming catalyst comprising a support MgAl2O4 and an active metal component supported on the support. The active metal component comprises a first metal element, a second metal element, and a third metal element. The first metal element is Ni, the second metal element is Bi, and the third metal element is one or more of Co, Ru, and Ag. The specific surface area of ​​the MgAl2O4 support is 120 m². 2 / g or more. The catalyst of the present invention, at 120m 2Using MgAl2O4 with a specific surface area of ​​over / g as a support, combined with the active components of this invention, it has the advantages of good thermal stability and high activity. No support reaction occurs under high temperature and high pressure conditions, and pore issues are not involved. During the reaction, the catalyst ensures uniform dispersion of the active components on the support, preventing agglomeration.

[0020] According to a preferred embodiment of the present invention, based on the total mass of the catalyst, the content of the first metal Ni is 2-10.2 wt.%, preferably 2-3 wt.%, the content of the second metal Bi is 0.01-3 wt.%, preferably 1-1.2 wt.%, and the content of the third metal is 0.01-3 wt.%, preferably 0.2-0.4 wt.%. Using the aforementioned proportions can further improve the stability and activity of the catalyst.

[0021] According to a preferred embodiment of the present invention, the specific surface area of ​​the MgAl2O4 support is 120-130 m². 2 / g. Using the aforementioned support can further improve the stability and activity of the catalyst.

[0022] Catalysts possessing the aforementioned features of this invention can achieve the objectives of this invention. There are no special requirements for the preparation method of the catalyst. According to a preferred embodiment of this invention, this invention provides a method for preparing the catalyst described in this invention, wherein the method includes: impregnating and contacting a source solution containing an active metal component in a specified ratio with a support MgAl2O4, drying by rotary evaporation to obtain a solid, and then subjecting it to calcination, reduction, and passivation.

[0023] In this invention, the impregnation contact can be a conventional impregnation loading method and condition. According to a preferred embodiment of the invention, the conditions of the impregnation contact include: a solid-liquid ratio of 1-2.5:100, preferably 1.4-2:100.

[0024] In this invention, the solid-liquid ratio refers to the weight ratio of the carrier MgAl2O4 to the source solution of the active metal component.

[0025] According to a preferred embodiment of the present invention, the immersion contact time is 3-20 hours, preferably 3-5 hours.

[0026] According to a preferred embodiment of the present invention, the immersion contact temperature is 20-30°C.

[0027] According to the present invention, the drying, calcination, reduction, and passivation can all be performed using conventional techniques.

[0028] According to a preferred embodiment of the present invention, the conditions for rotary drying include: a temperature of 50-180°C, preferably 80-130°C; and a time of 3-15 hours, preferably 3-5 hours.

[0029] According to a preferred embodiment of the present invention, the calcination conditions include: raising the temperature to 550°C-1100°C at a rate of 1-5°C / min, preferably 600-800°C; and calcining for 3-20 hours, preferably 3-5 hours.

[0030] According to a preferred embodiment of the present invention, the reduction conditions include: a temperature of 600-1100°C and reduction in a hydrogen atmosphere for 1-4 hours.

[0031] According to a preferred embodiment of the present invention, the passivation conditions include: passivation in an Ar / O2 mixture for 1-4 hours at a temperature of 600-1100°C.

[0032] In this invention, the first metal source, the second metal source, and the third metal source can be common compounds, such as each including, but not limited to, one or more selected from nitrates and hydrochlorides.

[0033] The catalyst of this invention has a simple preparation process, high reforming activity, and good stability. It remains stable after 150 hours of stable operation under high temperature and high pressure conditions for methane dry reforming, with almost no carbon buildup, completely solving the problem of carbon buildup and deactivation in methane dry reforming under high pressure. The method of this invention can be applied to industrial syngas production technology.

[0034] The catalyst of the present invention can be used in the reaction technology of dry reforming of methane and carbon dioxide to produce syngas, and can also be used as a catalyst for methane combined reforming or triple reforming.

[0035] This invention provides the application of the catalyst described herein in the production of syngas from methane through dry reforming, combined reforming, or triple reforming.

[0036] This invention provides a method for preparing syngas by dry reforming methane with carbon dioxide. In the presence of the reforming catalyst described in this invention, methane and carbon dioxide are contacted. Preferably, the contact conditions include: the flow rates of methane and carbon dioxide are each 30-70 ml / min; the pressure is 0.5-4.0 MPa; and the temperature is 600-1100℃.

[0037] X-ray polycrystalline powder diffraction (XRD) was performed using a BRUKER D8 Advance SS X-ray diffractometer to analyze the crystal structure of the samples. Using a Cu target with Kα1 as the radiation source, the samples were scanned and recorded at 40 kV and 40 mA, with diffraction angles 2θ = 5–80°, to obtain XRD diffraction patterns for characterizing the crystalline phases.

[0038] In this invention, the thermogravimetric analysis characterization of the catalyst was performed on a TGA Q600 SDT thermogravimetric analyzer from Thermo Fisher Scientific in the United States. This thermogravimetric analyzer includes a gas flow control and mass detection system, which can accurately measure the change in mass of the catalyst over time or temperature during the heating process. The heating test conditions were: 25°C in an air atmosphere, heating rate of 10°C / min, up to 800°C.

[0039] Catalyst evaluation: Weigh 0.05-1.5g of methane dry reforming catalyst, mix it evenly with silicon carbide diluent, and then load it into the fixed-bed isothermal section. After confirming that the reactor is leak-proof, raise the temperature to 600℃-1100℃, and then introduce the reaction gas. The flow rates of methane and carbon dioxide are the same, at 30-70ml / min. Finally, increase the pressure to 0.5-4MPa for the reaction.

[0040] Methane conversion rate:

[0041] Carbon dioxide conversion rate:

[0042] Hydrogen / Carbon Monoxide:

[0043]

[0044]

[0045] Where X represents conversion rate, S represents selectivity, and F represents gas flow rate.

[0046]

Example 1

[0047] Catalyst preparation: At 20℃, 0.3257 g of nickel nitrate, 0.0679 g of bismuth nitrate, and 0.0407 g of cobalt nitrate were weighed and dissolved in deionized water to prepare a solution. Then, MgAl2O4 (specific surface area 121 m²) with a high specific surface area prepared by the Pechini method was added. 2 2.6461 g of support (MgAl2O4 support to active metal component source solution) was prepared, with a solid-liquid weight ratio of 1.8:100. The mixture was stirred for 4 h, followed by rotary evaporation at 120 °C for 6 h. The dried sample was then placed in a muffle furnace and calcined at 850 °C at a rate of 3 °C for 4 h. The resulting catalyst was then reduced at 850 °C under a hydrogen atmosphere for 2 h, cooled to room temperature, and passivated in an Ar / O2 mixed gas for 2 h. The crystal phase of the catalyst was characterized by XRD, as shown below. Figure 1 As shown, it exhibits the crystal phase of magnesium aluminum spinel.

[0048] The stability evaluation results of the catalyst are shown in [link to relevant documentation]. Figure 5As shown in Table 1, the catalyst exhibits excellent stability under high temperature and pressure conditions, with no decrease in activity after 150 hours of reaction. To understand the changes in the surface composition and structure of the catalyst after the reaction, XRD diffraction analysis was performed. (See Table 1 for details.) Figure 2 The spectra showed that the structure of the catalyst remained unchanged after the reaction compared to the fresh catalyst, and no carbon deposition peaks were observed. To understand the quantity and type of surface carbon deposition on the catalyst after the reaction, thermogravimetric characterization was performed, see [reference needed]. Figure 4 As can be seen, after 150 hours of reaction, only a small amount of gasifiable soft carbon deposits (<2.0 wt.%) remained on the catalyst surface. This indicates that the catalyst has a significant anti-carbon deposition effect and excellent catalyst stability.

[0049]

Examples 2-6

[0050] Following the catalyst synthesis steps shown in Example 1, the amount of bismuth nitrate added was varied to synthesize catalysts of the present invention with Bi contents of 0.05 wt.%, 0.5 wt.%, 1.5 wt.%, 2 wt.%, and 2.5 wt.%, respectively. The catalyst formulations are shown in Table 1. The catalyst evaluation method was the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0051]

Examples 7-11

[0052] Following the catalyst synthesis steps shown in Example 1, the amount of nickel nitrate added was varied to synthesize catalysts of the present invention with Ni contents of 2 wt.%, 2.5 wt.%, 3 wt.%, 3.5 wt.%, and 4 wt.%, respectively. The catalyst formulations are shown in Table 1. The catalyst evaluation method was the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0053]

Examples 12-14

[0054] Following the catalyst synthesis steps shown in Example 1, the amount of cobalt nitrate added was varied to synthesize catalysts of the present invention with Co contents of 0.05 wt.%, 0.5 wt.%, and 2.5 wt.%, respectively. The catalyst formulations are shown in Table 1. The catalyst evaluation method was the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0055]

Example 15

[0056] Following the catalyst synthesis method and steps shown in Example 1, cobalt nitrate was replaced with silver nitrate, and the catalyst formulation is shown in Table 1. The catalyst evaluation method was the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0057]

Example 16

[0058] Following the catalyst synthesis method and steps shown in Example 1, cobalt nitrate was replaced with ruthenium nitrate, and the catalyst formulation is shown in Table 1. The catalyst evaluation method was the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0059]

Examples 17-27

[0060] Following the catalyst synthesis steps shown in Example 1, the solid-liquid ratio, impregnation time and temperature, and calcination time and temperature were varied during catalyst preparation to obtain the catalyst of this invention. The catalyst preparation method is shown in Table 2. The catalyst evaluation method is the same as in Example 1, and the catalytic reaction results are shown in Table 3.

[0061] Table 1. Synthesis raw materials, proportions, and specific surface areas of the catalysts in Examples 1-16

[0062]

[0063]

[0064] Table 2. Preparation conditions of catalysts in Examples 17-27

[0065]

[0066]

[0067] Comparative Example 1

[0068] Catalyst preparation: Weigh 0.4071 g of nickel nitrate, dissolve it in deionized water to prepare a solution, and then add MgAl2O4 (specific surface area 121 m²) prepared by the Pechini method, which has a high specific surface area. 2 2.6461 g of support was stirred for more than 3 hours; then rotary evaporation was performed; the dried sample was placed in a muffle furnace and calcined at 850 °C at a rate of 3 °C for 4 hours. The resulting catalyst was then reduced at 850 °C in a hydrogen atmosphere for 2 hours, cooled to room temperature, and then passivated in an Ar / O2 mixed gas for 2 hours.

[0069] The stability evaluation results of the catalyst are as follows Figure 6 As shown in Table 3, the catalyst performance gradually decreased in the initial stage of the reaction, and the catalyst activity dropped sharply with the extension of reaction time, indicating that the catalyst was deactivated. After 150 h of reaction, the methane conversion rate decreased from the initial 50% to 12%. The XRD pattern of the catalyst after the reaction is shown in [Figure 3]. Figure 3 As can be seen from the figure, the catalyst after the reaction exhibits a relatively obvious characteristic peak at 2θ = 26.6° belonging to the (003) crystal plane of graphitic carbon, indicating that the catalyst has undergone carbon deposition and deactivation. The TG results of the catalyst after the reaction are shown in [Figure number missing]. Figure 4It can be seen that two types of carbon deposits exist on the catalyst surface: stubborn carbon deposits and soft carbon deposits, and the carbon deposit content is very high (>10.0 wt.%). XRD and TG results show that a large amount of carbon deposits are deposited on the catalyst surface.

[0070] Comparative Example 2

[0071] The catalyst was prepared using a specific surface area of ​​39m. 2 / g MgAl2O4 was used as the support, and everything else was the same as in Example 1. The TG results of the catalyst after the reaction are shown in [Figure 1]. Figure 4 It can be seen that soft carbon deposits exist on the catalyst surface, with a carbon content of 1.8 wt.%.

[0072] Comparative Example 3

[0073] Catalyst preparation: Weigh 0.3664 g of nickel nitrate and 0.0407 g of cobalt nitrate, dissolve them in deionized water to prepare a solution, and then add a high specific surface area MgAl2O4 support (specific surface area 251 m²) prepared by the Pechini method. 2 2.6461 g of the sample was stirred for more than 3 hours, followed by rotary evaporation. The dried sample was then placed in a muffle furnace and calcined at 850°C at a rate of 3°C for 4 hours. The resulting catalyst was then reduced at 850°C under a hydrogen atmosphere for 2 hours. After 150 hours of reaction, the TG results of the catalyst after the reaction are shown in [Figure number missing]. Figure 4 It can be seen that there are two types of carbon deposits on the catalyst surface: stubborn carbon deposits and soft carbon deposits, with a total carbon deposit amount of 7.4 wt.%.

[0074] Table 3 Comparison of catalytic performance of catalysts in Examples 1-27 of the present invention and Comparative Examples 1-3 in the dry reforming reaction of methane and carbon dioxide.

[0075]

[0076]

[0077]

[0078] As shown in Table 3, compared with the monometallic Ni catalyst and the bimetallic Ni-Co catalyst, the trimetallic Ni-Bi-Co catalyst exhibits the best catalytic stability. After 150 hours of high-temperature and high-pressure reaction, almost no catalyst deactivation occurred, and the conversion rates of methane and carbon dioxide were maintained. The initial activities of Comparative Examples 1 and 2 were slightly higher than those of Examples 1-27, but after a long reaction time, the conversion rates of methane and carbon dioxide decreased rapidly, and carbon deposition and deactivation occurred quickly. After the reaction, the catalysts of Comparative Examples 1 and 2 were almost completely deactivated, generating a large amount of carbon deposits, and the H2 content in the products was high, thus increasing the H2 / CO ratio. The catalyst of Comparative Example 3 used a support with a small specific surface area and low metal component dispersion, resulting in lower initial activity and lower stability than Example 1.

[0079] Based on the data in the tables above, it can be seen that the trimetallic catalyst of this invention exhibits significantly improved catalytic performance in the dry reforming reaction of methane and carbon dioxide, and can achieve long-term stability evaluation under conditions of 850℃ and 2MPa. Table 3 shows the examples and comparative examples, indicating that the catalyst of this invention exhibits superior stability and anti-carbon deposition performance when only the three metal components are present. Table 3 also shows that each of the three metal components has an optimal input amount, and the catalyst activity decreases with increasing Bi content and increases with increasing Co and Ni content. The preferred Ni content is 2-3 wt.%, the Bi content is 1-1.2 wt.%, and the third metal content is 0.2-0.4 wt.%. The experimental data in Examples 17-27 demonstrate that different preparation conditions have different effects on catalyst performance; a large specific surface area support is beneficial to improving catalyst activity and stability; the impregnation time, impregnation temperature, calcination time, and calcination temperature of the catalyst all need to be optimized during the preparation process.

[0080] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A reforming catalyst, characterized in that, The catalyst contains a support MgAl2O4 and an active metal component supported on the support. The active metal element consists of a first metal element, a second metal element, and a third metal element. The first metal element is Ni, the second metal element is Bi, and the third metal element is one or more of Co, Ru, and Ag. The specific surface area of ​​the support MgAl2O4 is 120-350 m². 2 / g; Based on the total mass of the catalyst, the content of the first metal Ni is 2-3 wt.%; the content of the second metal Bi is 1-1.2 wt.%; and the content of the third metal is 0.2-0.4 wt.%.

2. The method for preparing the catalyst according to claim 1, wherein, The method includes: impregnating and contacting a source solution containing an active metal component in a specified ratio with a carrier MgAl2O4, drying by rotary evaporation to obtain a solid, and then calcining, reducing, and passivating it.

3. The preparation method according to claim 2, wherein, The conditions for the immersion contact include: The solid-liquid ratio is 1-2.5:100; and / or the time is 3-20 h; and / or the temperature is 20-30 ℃; The solid-liquid ratio refers to the weight ratio of the carrier MgAl2O4 to the source solution of the active metal component.

4. The preparation method according to claim 3, wherein, The solid-liquid ratio is 1.4-2:100; and / or the time is 3-5 hours.

5. The preparation method according to claim 2, wherein, The conditions for rotary drying include: a temperature of 50-180 ℃ and a time of 3-15 h.

6. The preparation method according to claim 5, wherein, The conditions for rotary drying include: a temperature of 80-130 ℃ and a time of 3-5 h.

7. The preparation method according to claim 2, wherein, The calcination conditions include: increasing the temperature to 550℃-1100℃ at a rate of 1-5℃ / min; and calcining for 3-20 h.

8. The preparation method according to claim 7, wherein, The calcination conditions include: heating to 600-800℃ at a rate of 1-5℃ / min; and calcining for 3-5 hours.

9. The preparation method according to claim 2, wherein, The reduction conditions include: a temperature of 600-1100 ℃ and a reduction in a hydrogen atmosphere for 1-4 h; The passivation conditions include: passivation in an Ar / O2 mixture for 1-4 h at a temperature of 600-1100 ℃.

10. The application of the catalyst according to claim 1 in the dry reforming of methane and carbon dioxide to produce syngas.

11. A method for preparing syngas by dry reforming methane with carbon dioxide, characterized in that, Methane is contacted with carbon dioxide in the presence of the reforming catalyst as described in claim 1.

12. The method according to claim 11, wherein, The contact conditions include: methane and carbon dioxide flow rates of 30-70 ml / min each; pressure of 0.5-4.0 MPa; and temperature of 600-1100℃.

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