Sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst as well as preparation method and application thereof

Abstract

The invention relates to the technical field of catalytic materials, and discloses a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst as well as a preparation method and an application of the sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst. According to the catalyst, hydroxyapatite (HAP) is used as a carrier, NiFe alloy is used as an active component, CeLaOx is used as a composite additive, and the problems that a traditional catalyst is prone to sulfur poisoning and sintering inactivation are solved through the three-element synergistic effect of'carrier-active component-additive '. Under the conditions that the temperature is 350 DEG C and the air speed is 30000 mL.g <-1 >. H <-1 >, the CO / CO2 conversion rate of the catalyst exceeds 90%, the CH4 selectivity is nearly 100%, and the sulfur-resistant effect is remarkable under the sulfur-containing working condition. The catalyst is suitable for coal pyrolysis gas multi-component coupling methanation reaction, high-value utilization of coal-based energy is achieved, and the application prospect is wide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalytic materials, in particular to a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst, a preparation method and application thereof, and especially to the application of the catalyst in a coal pyrolysis gas multi-component coupling methanation reaction. BACKGROUND

[0002] As an important intermediate product of clean coal conversion, coal pyrolysis gas is rich in CO, CO2, H2 and trace amounts of H2S, etc., and can be converted into synthetic natural gas through a methanation reaction, which is a key technology for realizing high-value utilization of coal-based energy and relieving the contradiction between supply and demand of natural gas. However, this process faces the problem of catalyst sulfur poisoning. Trace amounts of H2S can form strong bonds with active metals, leading to irreversible poisoning, and high-temperature reactions can easily cause metal particle sintering, which can easily lead to rapid deactivation of the catalyst.

[0003] In the prior art, Ni-based catalysts have become mainstream due to their high activity and high CH4 selectivity, but pure Ni can easily react with H2S to form Ni3S2, leading to irreversible poisoning. Fe-based catalysts have better sulfur resistance, but have lower activity and poor C2 + hydrocarbon selectivity. Although NiFe alloys can balance activity and sulfur resistance, traditional supports such as Al2O3 and SiO2 lack strong interaction sites, which can easily lead to alloy particle migration and agglomeration. Hydroxyapatite (HAP) as a support has unique surface chemical properties and can anchor active components, but single HAP supports lack sulfur resistance and sintering resistance. CeO2 and La2O3 as additives have anti-carbon deposition and anti-sulfur effects, respectively, but there is still a lack of research on the synergistic effect of NiFe active components, CeLaOx additives and HAP supports, especially in the performance verification of a coal pyrolysis gas multi-component coexistence system.

[0004] Therefore, developing a catalyst with high activity, strong sulfur resistance and sintering resistance, and constructing a ternary synergistic system of "support-active component-additive", is a core requirement for solving the industrialization bottleneck of coal pyrolysis gas methanation. SUMMARY

[0005] The present application aims to solve the problems of catalyst sulfur poisoning and sintering deactivation in the prior art, and provides a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst, a preparation method and application thereof. Through the synergistic effect of the support, active component and additive, efficient coupling conversion of coal pyrolysis gas multi-components is achieved.

[0006] To achieve the above objectives, the present invention provides a NiFe-CeLaOx / HAP methanation catalyst, characterized in that it comprises a support, an active component, and a composite additive; the support is hydroxyapatite (HAP), the composite additive is CeLaOx, and the active component is a NiFe alloy; the CeLaOx composite additive and the NiFe alloy are uniformly dispersed on the surface of the HAP support, forming a ternary synergistic structure of "support-active component-additive".

[0007] Preferably, the molar ratio of Ce to La in the CeLaOx composite additive is (1:2) to (2:1), and the total loading is 8% to 12%.

[0008] Furthermore, the molar ratio of Ni to Fe in the NiFe alloy is (1:3) to (3:1), and the total loading is 10% to 20%.

[0009] More preferably, the HAP carrier has a Ca / P molar ratio of 1.60 to 1.70, a mesoporous rod-like structure, and a specific surface area of ​​80 to 90 m². 2 / g, with an average pore size of 10–11 nm.

[0010] To achieve the above objectives, the present invention also provides a method for preparing a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst, characterized by comprising the following steps:

[0011] Step 1: Preparation of HAP carrier. Calcium nitrate tetrahydrate and diammonium hydrogen phosphate were dissolved in equal volumes of deionized water at a Ca / P molar ratio of 1.60–1.70 to obtain solutions A and B, respectively. Solution B was added dropwise to solution A at a rate of 0.8–1.2 mL / min. The pH was adjusted to 9.5–10.5 with ammonia. After stirring for 20–40 min, a hydrothermal reaction was carried out at 110–130 °C for 10–14 h. The mixture was then centrifuged and washed until the pH reached 6.5–7.5. It was dried at 70–90 °C for 10–14 h and calcined at 480–520 °C for 3–5 h at a heating rate of 4–6 °C / min to obtain the HAP carrier.

[0012] Step 2: Composite additive loading process. Weigh cerium nitrate hexahydrate and lanthanum nitrate hexahydrate according to the Ce / La molar ratio (1:2) to (2:1), dissolve them in deionized water to prepare an impregnation solution, impregnate them with an equal volume of HAP carrier, let stand at room temperature for 10 to 14 hours, dry at 70 to 90°C for 10 to 14 hours, calcine at 480 to 520°C for 2 to 4 hours, with a heating rate of 4 to 6°C / min, to obtain CeLaOx / HAP intermediate;

[0013] Step 3: Active component loading process. Weigh nickel nitrate hexahydrate and ferric nitrate nonahydrate according to the Ni / Fe molar ratio (1:3) to (3:1) and the total loading amount of 10% to 20%. Dissolve them in deionized water to prepare an impregnation solution. Impregnate the solution with an equal volume of CeLaOx / HAP intermediate. Let it stand at room temperature for 10 to 14 hours, dry it at 70 to 90°C for 10 to 14 hours, and calcine it at 480 to 520°C for 2 to 4 hours with a heating rate of 4 to 6°C / min to obtain the oxidized catalyst.

[0014] Step 4, reduction treatment: H2 / N2 mixed gas (volume ratio 1:3 to 1:5) is introduced at a flow rate of 40 to 60 mL / min, and reduction is carried out at 430 to 470 °C for 2 to 4 h with a heating rate of 4 to 6 °C / min. Under N2 protection, the mixture is cooled to room temperature to obtain the target NiFe-CeLaOx / HAP catalyst.

[0015] Preferably, in step one, the centrifugation speed is 7000-9000 r / min and the centrifugation time is 8-12 min.

[0016] Furthermore, in steps two and three, the volume of the impregnation liquid is consistent with the water absorption rate of the corresponding carrier or intermediate.

[0017] More preferably, the ammonia concentration in step one is 25% to 28%, and the volume ratio of the H2 / N2 mixed gas in step four is 1:4.

[0018] To achieve efficient coupling conversion of multiple components in coal pyrolysis gas, this invention further provides an application of a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst in the multi-component coupled methanation reaction of coal pyrolysis gas. The reaction conditions are characterized by: a temperature of 300–400℃ and a space velocity of 20,000–40,000 mL·g. -1 ·h -1 At atmospheric pressure, the simulated coal pyrolysis gas volume composition is CO2 (8-15)%, CO (15-30)%, with other gases being N2 and containing trace amounts of H2S, and hydrogen is introduced.

[0019] Preferably, the simulated coal pyrolysis gas has an H to C ratio of (4-5):1, an H2S concentration ≤500ppm, a catalyst loading of 0.2g, a particle size of 40-60 mesh, and is filled with quartz sand at the top and bottom to eliminate dead volume, making it suitable for industrial fixed-bed reactor conditions.

[0020] The present invention provides a sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst, its preparation method, and its application, which have the following advantages compared with the prior art:

[0021] (1) Excellent catalytic performance and strong stability: Through the synergistic effect of the ternary catalyst “NiFe alloy active component-CeLaOx composite additive-HAP support”, the methane selectivity is almost 100%, and it also has excellent resistance to sulfur poisoning, which solves the industry pain point of easy deactivation of existing catalysts.

[0022] (2) The preparation process is simple and the cost is controllable: the conventional impregnation method is used for preparation. The steps are simple and easy to operate. No complicated equipment is required. Common nitrates and HAP carriers are selected as raw materials, which are inexpensive and can be directly used for industrial scale-up production.

[0023] (3) Wide applicability and high practicality: It can work efficiently under mild conditions (300-400℃, normal pressure) of pyrolysis gas methanation coupling reaction without the need to modify existing industrial equipment. It can promote the clean and efficient conversion of pyrolysis gas resources and has extremely high promotion and application value.

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0025] Figure 1 XRD pattern of hydroxyapatite (HAP) support with a Ca / P ratio of 1.67;

[0026] Figure 2 Here are the SEM (a) and TEM (b) images of the HAP;

[0027] Figure 3 XRD pattern of NiFe-CeLaOx / HAP catalyst;

[0028] Figure 4 TEM image of NiFe-CeLaOx / HAP catalyst;

[0029] Figure 5 Stability and sulfur poisoning resistance curves of NiFe-CeLaOx / HAP catalyst

[0030] like Figure 1 The XRD pattern of the HAP support with a Ca / P ratio of 1.67 is shown. The strong characteristic diffraction peaks of the (002), (211), and (112) crystal planes at 2θ = 25.9°, 31.8°, and 32.2° indicate that the HAP crystal structure is complete. Figure 2 In the hydrothermal synthesis, HAP is short rod-shaped, uniform in morphology, and has good crystallinity, which is consistent with the XRD characteristics. It also has a regular structure and abundant interparticle voids, which is conducive to metal loading. It has good dispersibility when the Ca / P ratio is 1.67, but it tends to agglomerate or form irregular blocky particles if it deviates from this ratio. Figure 3 In the diffraction pattern, characteristic diffraction peaks of Ni or Ni-Fe alloys appear at 2θ = 44.5° and 51.8°, but no elemental Fe peaks are observed.Figure 4 In the images, (a) shows that the HAP rod-like structure remains intact, and (b) shows that the active components and auxiliaries are uniformly dispersed in small particles, which is beneficial for the exposure of active sites and the enhancement of catalytic activity. Figure 5 In the H2S-free operation for 800 hours, the CO and CO2 conversion rates stabilized at 87.12% and 85.01%, respectively, with the activity remaining at 90% of the initial value. After introducing 100 ppm H2S, the stable conversion rates reached 82.01% and 80.07%, respectively, recovering to 83.85% and 81.93% after the introduction was stopped, indicating partial reversibility of sulfur poisoning. Introducing 200 ppm H2S resulted in a greater decrease, dropping to 77.07% and 75.01% after 500 hours. The high stability of this catalyst is ensured by a triple synergistic effect: the Ca²⁺ of HAP… 2+ -PO4 3- Anchoring NiFe alloys inhibits sintering; CeLaOx synergistically resists sulfur, La / Ce preferentially captures sulfur, and Ce's oxygen vacancies oxidize carbon species; NiFe alloy electron transfer enhances activity, matching the needs of coal pyrolysis gas conversion. Detailed Implementation

[0031] The following examples and test cases will further illustrate the present invention, but the present invention is not limited to the following examples and test cases.

[0032] Example 1: Preparation of HAP carrier

[0033] According to a Ca / P molar ratio of 1.67, 2.36 g of calcium nitrate tetrahydrate was dissolved in 50 mL of deionized water to obtain solution A, and 0.93 g of diammonium hydrogen phosphate was dissolved in 50 mL of deionized water to obtain solution B. Under stirring at 30 °C, solution B was added dropwise to solution A at a rate of 1 mL / min, and the pH was adjusted to 10.0 with 25% ammonia water. Stirring was continued for 30 min. The mixture was transferred to a hydrothermal reactor and reacted at 120 °C for 12 h. After cooling, the mixture was centrifuged at 8000 r / min for 10 min, and the precipitate was collected and washed with deionized water until the pH reached 7.0. The mixture was dried at 80 °C for 12 h and calcined at 500 °C for 4 h with a heating rate of 5 °C / min to obtain the HAP carrier.

[0034] Product Validation: Figure 1 XRD characterization showed that the diffraction peaks completely matched the HAP standard card (JCPDS No. 09-0432), indicating a pure phase structure. Figure 2 SEM and TEM observations revealed a uniform short rod-shaped structure with numerous voids between particles; BET measurements showed a specific surface area of ​​87.36 m². 2 / g, pore volume 0.2311cm³ 3 / g, average pore size 10.54nm; CO2-TPD test showed that the number of strong basic sites reached 0.29mmol / g.

[0035] Example 2: Preparation of catalysts with different Ni / Fe molar ratios

[0036] The HAP support prepared in Example 1 was used to prepare a composite additive impregnation solution with a Ce / La molar ratio of 1:1 and a total loading of 10%. After impregnation with an equal volume, the solution was allowed to stand for 12 hours, dried at 80°C for 12 hours, and calcined at 500°C for 3 hours to obtain a CeLaOx / HAP intermediate. Active component impregnation solutions were prepared with Ni / Fe molar ratios of 3:1, 1:1, and 1:3 (total loading of 15%), and impregnated with the intermediate with an equal volume. After standing for 12 hours, drying at 80°C for 12 hours, and calcining at 500°C for 3 hours, oxidized catalysts were obtained. A H2 / N2 (1:4) mixed gas was introduced at a flow rate of 50 mL / min, and the solution was reduced at 450°C for 3 hours with a heating rate of 5°C / min. The solution was cooled under N2 protection to obtain catalysts 2-1 (Ni / Fe = 3:1), 2-2 (Ni / Fe = 1:1), and 2-3 (Ni / Fe = 1:3), respectively.

[0037] Product verification: Catalyst 2-2 was characterized by XRD ( Figure 3 The characteristic diffraction peaks of NiFe alloys were observed, but no elemental Fe impurity peaks were observed. Figure 4 TEM observation showed that the active components and additives were uniformly dispersed on the carrier surface, with no obvious agglomeration.

[0038] Example 3: Preparation of catalysts with different Ce / La molar ratios

[0039] The HAP support prepared in Example 1 was used to prepare composite additive impregnation solutions at Ce / La molar ratios of 2:1, 1:1, and 1:3 (total loading 10%). After impregnation with equal volumes, standing for 12 hours, drying at 80°C for 12 hours, and calcination at 500°C for 3 hours, different CeLaOx / HAP intermediates were obtained. An active component impregnation solution was prepared at a Ni / Fe molar ratio of 1:1 and a total loading of 15%. The active component was impregnated with the intermediates at equal volumes. The subsequent steps were the same as in Example 2, and catalysts 3-1 (Ce / La = 2:1), 3-2 (Ce / La = 1:1), and 3-3 (Ce / La = 1:3) were obtained.

[0040] Product verification: XPS characterization of catalyst 3-2 showed that Ce was Ce2. 3+ / Ce 4+ In mixed valence states, La mainly exhibits Lao valence. 3+ exist.

[0041] Example 4: Preparation of catalysts with different total NiFe loading

[0042] The HAP support prepared in Example 1 was used to prepare Ce1La1-O / HAP intermediates at a Ce / La molar ratio of 1:1 and a total loading of 10%. Active component impregnation solutions were prepared at NiFe total loadings of 10%, 15%, and 20% (Ni / Fe = 1:1), and impregnated with the intermediates in equal volumes. The subsequent steps were the same as in Example 2, and catalysts 4-1 (10%), 4-2 (15%), and 4-3 (20%) were obtained, respectively.

[0043] Product validation: The specific surface area of ​​catalyst 4-2 was 97.54 m² according to BET testing. 2 / g, pore volume 0.2433cm³ 3 / g, with an average pore size of 11.02nm, providing ample space for the dispersion of active components.

[0044] Example 5: Preparation of the optimal catalyst

[0045] By integrating the optimal parameters: Ca / P molar ratio 1.67, Ni / Fe molar ratio 1:1, Ce / La molar ratio 1:1, total NiFe loading 15%, and total CeLaOx loading 10%, the catalyst was prepared according to the steps of Examples 1 to 4, thus obtaining the optimal catalyst NiFe-CeLaOx / HAP.

[0046] Experimental Example 1: Characterization and Analysis of Physicochemical Properties of Catalysts

[0047] To clarify the key physicochemical characteristics such as the microstructure and surface properties of the HAP supports and catalysts prepared in Examples 1-5, a variety of characterization methods were used for systematic analysis, as detailed below:

[0048] (1) Test objects: HAP supports and corresponding catalysts prepared in Examples 1-5;

[0049] (2) Test methods: X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption (BET), carbon dioxide temperature programmed desorption (CO2-TPD), and hydrogen temperature programmed reduction (H2-TPR).

[0050] (3) Test results:

[0051] XRD analysis: The HAP support exhibits a pure phase structure with sharp diffraction peaks and no impurities; the optimal catalyst (Cat-5) prepared in Example 5 shows obvious characteristic diffraction peaks of NiFe alloy, CeO2 and La2O3, indicating that the active components and additives were successfully loaded and have good crystallinity.

[0052] SEM / TEM observation: The HAP support has a uniform short rod morphology and regular structure; the NiFe active component and Ce and La promoters in the optimal catalyst (Cat-5) are uniformly dispersed on the surface of the HAP support in the form of nano-sized particles, without obvious agglomeration, which is conducive to exposing active sites.

[0053] BET test: The optimal catalyst (Cat-5) has a specific surface area of ​​97.54 m². 2 / g, pore volume is 0.2433cm³ 3 / g, with an average pore size of 11.02nm. The suitable pore structure can reduce the mass transfer resistance between reactants and products.

[0054] CO2-TPD analysis: The surface of the optimal catalyst (Cat-5) contains weakly basic and moderately basic sites, among which the number of moderately basic sites is sufficient to efficiently adsorb and activate CO2 molecules.

[0055] H2-TPR test: The reduction peak of the optimal catalyst (Cat-5) is concentrated in the range of 300-400℃, indicating that it contains a large number of reducible active species and that there is a moderate interaction between the active component and the support, which is conducive to the initiation and progress of the catalytic reaction.

[0056] Experimental Example 2: Evaluation of Catalyst Methanation Activity

[0057] To investigate the effects of total metal loading, Ni / Fe molar ratio, and Ce / La molar ratio on the methanation activity of the catalyst, the catalyst prepared in Example 5 (Cat-5) was used for performance testing, as detailed below:

[0058] (1) Test subject: HAP supported catalyst (Cat-5) prepared in Example 5;

[0059] (2) Test conditions: A fixed-bed quartz reactor was used, with a catalyst loading of 0.2 g (40-60 mesh), a reaction temperature of 350℃, and a space velocity of 30000 mL·g. -1 ·h -1 At atmospheric pressure, the reaction feedstock is simulated coal pyrolysis gas (containing 10-20% CO2, 15-30% CO, and the remainder is N2 balance gas);

[0060] (3) Test results:

[0061] The catalyst exhibits optimal activity when the Ca / P molar ratio is 1.67, the Ni / Fe molar ratio is 1:1, the Ce / La molar ratio is 1:1, the total NiFe loading is 15%, and the total CeLaOx loading is 10%, with a CO conversion rate of 97.22%, a CO2 conversion rate of 94.54%, and a CH4 selectivity of nearly 100%. Example 3: Evaluation of the optimal catalyst's stability and resistance to sulfur poisoning.

[0062] The optimal catalyst (Cat-5) prepared in Example 5 was selected to investigate its long-term stability and resistance to sulfur poisoning in the methanation reaction, as detailed below:

[0063] (1) Test subject: The optimally proportioned HAP supported catalyst (Cat-5) prepared in Example 5;

[0064] (2) Test conditions: reaction temperature 350℃, space velocity 30000 mL·g -1 ·h -1 At atmospheric pressure, simulated coal pyrolysis gas containing no H2S, 100ppm H2S, and 200ppm H2S were introduced respectively.

[0065] (3) Test results:

[0066] Stability: After 800 hours of continuous operation in the absence of H2S, the catalyst activity remained stable, the CO conversion rate remained at 87.12%, the CO2 conversion rate remained stable at 85.01%, and the activity retention rate reached 90%.

[0067] Sulfur resistance: After operating for 500 hours with 100 ppm H2S, the CO conversion rate remained stable at 82.01%, the CO2 conversion rate at 80.07%, and the activity retention rate at 85%. After stopping the H2S supply, the catalyst conversion rate could recover to 83.85% (CO) and 81.93% (CO2), with an activity recovery rate of 87%.

[0068] High sulfur tolerance: After operating for 500 hours in harsh conditions with 200 ppm H2S, the CO conversion rate can still be maintained at 77.07% and the CO2 conversion rate at 75.01%, demonstrating good resistance to sulfur poisoning.

[0069] The above description is merely a preferred embodiment and experimental example of the present invention, and does not constitute any limitation on the present invention. Any simple modifications, alterations, and equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the technical solution of the present invention.

Claims

1. A sulfur-resistant and sintering-resistant NiFe-CeLaOx / HAP methanation catalyst, characterized in that, It includes a carrier, an active component, and a composite additive; the carrier is hydroxyapatite (HAP), the active component is a NiFe alloy, and the composite additive is CeLaOx; the NiFe alloy and CeLaOx composite additive are uniformly dispersed on the surface of the HAP carrier to form a ternary synergistic structure of "carrier-active component-additive".

2. The catalyst according to claim 1, characterized in that, The HAP carrier has a Ca / P molar ratio of 1.60–1.70, a mesoporous rod-like structure, and a specific surface area of ​​80–90 m². 2 / g, with an average pore size of 10–11 nm.

3. The catalyst according to claim 1, characterized in that, The molar ratio of Ce to La in the CeLaOx composite additive is (1:2) to (2:1), and the total loading is 8% to 12%.

4. The catalyst according to claim 1, characterized in that, The molar ratio of Ni to Fe in the NiFe alloy is (1:3) to (3:1), and the total loading is 10% to 20%.

5. A method for preparing the catalyst according to any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Preparation of HAP carrier. Calcium nitrate tetrahydrate and diammonium hydrogen phosphate were dissolved in equal volumes of deionized water at a Ca / P molar ratio of 1.60–1.70 to obtain solutions A and B, respectively. Solution B was added dropwise to solution A at a rate of 0.8–1.2 mL / min. The pH was adjusted to 9.5–10.5 with ammonia. After stirring for 20–40 min, a hydrothermal reaction was carried out at 110–130 °C for 10–14 h. The mixture was then centrifuged and washed until the pH reached 6.5–7.

5. It was dried at 70–90 °C for 10–14 h and calcined at 480–520 °C for 3–5 h at a heating rate of 4–6 °C / min to obtain the HAP carrier. Step 2: Composite additive loading process. Weigh cerium nitrate hexahydrate and lanthanum nitrate hexahydrate according to the Ce / La molar ratio (1:2) to (2:1), dissolve them in deionized water to prepare an impregnation solution, impregnate them with an equal volume of HAP carrier, let stand at room temperature for 10 to 14 hours, dry at 70 to 90°C for 10 to 14 hours, calcine at 480 to 520°C for 2 to 4 hours, with a heating rate of 4 to 6°C / min, to obtain CeLaOx / HAP intermediate; Step 3: Active component loading process. Weigh nickel nitrate hexahydrate and ferric nitrate nonahydrate according to the Ni / Fe molar ratio (1:3) to (3:1) and the total loading amount of 10% to 20%. Dissolve them in deionized water to prepare an impregnation solution. Impregnate the solution with an equal volume of CeLaOx / HAP intermediate. Let it stand at room temperature for 10 to 14 hours, dry it at 70 to 90°C for 10 to 14 hours, and calcine it at 480 to 520°C for 2 to 4 hours with a heating rate of 4 to 6°C / min to obtain the oxidized catalyst. Step 4, reduction treatment: H2 / N2 mixed gas (volume ratio 1:3 to 1:5) is introduced at a flow rate of 40 to 60 mL / min, and reduction is carried out at 430 to 470 °C for 2 to 4 h with a heating rate of 4 to 6 °C / min. Under N2 protection, the mixture is cooled to room temperature to obtain the target NiFe-CeLaOx / HAP catalyst.

6. The preparation method according to claim 5, characterized in that, In step one, the centrifugation speed is 7000-9000 r / min and the centrifugation time is 8-12 min.

7. The preparation method according to claim 5, characterized in that, In steps two and three, the volume of the impregnation solution is consistent with the water absorption rate of the corresponding carrier or intermediate.

8. The preparation method according to claim 5, characterized in that, In step one, the concentration of ammonia water is 25% to 28%, and in step four, the volume ratio of H2 / N2 mixed gas is 1:

4.

9. The application of the catalyst according to any one of claims 1 to 4 in the multi-component coupled methanation reaction of coal pyrolysis gas, characterized in that, The reaction conditions were: temperature 300–400℃, space velocity 20,000–40,000 mL·g. -1 ·h -1 At atmospheric pressure, the simulated coal pyrolysis gas volume composition is CO2 (8-15)%, CO (15-30)%, with other gases being N2 and containing trace amounts of H2S, and hydrogen is introduced.

10. The application according to claim 9, characterized in that, The simulated coal pyrolysis gas composition has an H to C ratio of (4-5):1, an H2S concentration ≤500ppm, a catalyst loading of 0.2g, a particle size of 40-60 mesh, and is filled with quartz sand at the top and bottom to eliminate dead volume.

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