A preparation method and application of a modified metal sulfide catalyst for acid natural gas co-conversion

Abstract

This invention relates to the field of catalyst technology, specifically to a method for preparing and applying a modified metal sulfide catalyst for the co-conversion of acidic natural gas. The preparation method includes: S1. Dissolving ammonium molybdate tetrahydrate in a modified solvent and stirring until completely dissolved to obtain a transparent and homogeneous solution; S2. Adding 2-3 parts of a modified support precursor to the solution and transferring it to an autoclave for reaction for 22-24 hours; S3. Centrifuging the solution and washing the precipitate 2-3 times with deionized water and anhydrous ethanol, respectively, followed by drying and grinding to obtain the modified metal sulfide catalyst. This invention utilizes concentrated light technology to synergistically apply light and heat energy to the reaction system, achieving high-efficiency conversion at a lower temperature (450-550℃) and atmospheric pressure compared to traditional thermocatalysis, significantly reducing energy consumption. It is the first catalyst designed for CH4. 4 and H 2 A metal sulfide composite catalyst system for S-concentrated photocatalytic co-conversion converts two harmful / low-value gases into high-value CS in one step. 2 and clean H 2 This has enabled "waste treatment" and resource recycling.

Description

A method for preparing and applying a modified metal sulfide catalyst for the co-conversion of acidic natural gas. Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to a method for preparing and applying a modified metal sulfide catalyst for the co-conversion of acidic natural gas. Background Technology

[0002] Given the kinetic stability of methane molecules (CH bond energy 439 kJ / mol) and the inherent limitations of the Claus process for hydrogen sulfide, the development of mild and efficient novel conversion pathways is urgently needed. While photocatalysis has shown promise, existing systems suffer from fundamental limitations in catalyst performance, such as narrow light absorption range, severe carrier recombination, and poor control of surface reaction pathways. This results in low efficiency for the single conversion of CH4 or H2S, let alone the construction of a synergistic reaction network between the two. Therefore, developing rationally designed photocatalytic materials and corresponding application schemes for the specific reaction of CH4 and H2S co-conversion is a cutting-edge field that urgently needs exploration.

[0003] For H2S-involved reaction systems, metal sulfides (such as MoS2, WS2, and CoS2) exhibit unique intrinsic advantages compared to metal oxides or noble metals: their surface sulfur atoms are thermodynamically compatible with sulfur species in the reaction environment, maintaining structural stability and avoiding deactivation due to the formation of metal sulfates; the unsaturated coordination sites of metal sulfides (such as sulfur vacancies at the edges) are considered ideal active centers for the efficient adsorption and dissociation of H2S; many metal sulfides have narrow band gaps, enabling them to effectively utilize visible light, which meets the requirements of photothermal catalysis for light-absorbing materials.

[0004] Among numerous metal sulfides, molybdenum disulfide (MoS2) has been extensively studied in the field of catalysis due to its unique two-dimensional layered structure and tunable electronic properties. Theoretical studies generally suggest that the edge sites of MoS2, especially the molybdenum edges with sulfur vacancies, exhibit high activity for the decomposition of H2S. Despite its great potential, experimental studies on the direct use of MoS2 to catalyze the reforming of CH4 and H2S to produce hydrogen and CS2 are relatively few, and the results are not entirely satisfactory. Existing MoS2 catalysts used in the literature are mostly commercial powders or prepared through conventional high-temperature calcination and solid-state methods. These materials generally suffer from problems such as low specific surface area, insufficient exposure of edge active sites, and excessive crystallinity leading to a large proportion of basal inertness. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing and applying a modified metal sulfide catalyst for the co-conversion of acidic natural gas.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas includes the following preparation steps:

[0008] S1. Dissolve 0.8-1.2 parts by weight of ammonium molybdate tetrahydrate in 70-80 parts of modified solvent and stir until completely dissolved to obtain a transparent and homogeneous solution;

[0009] S2. Add 2-3 parts of the modified carrier precursor to the solution obtained in step S1 and transfer it to a polytetrafluoroethylene-lined autoclave. React at 170-180℃ for 22-24 hours.

[0010] S3. Centrifuge the solution after the reaction in step S2 for 8-10 min, wash the precipitate with deionized water and anhydrous ethanol 2-3 times respectively, and obtain the modified metal sulfide catalyst after drying and grinding.

[0011] The preparation of the modified carrier precursor includes the following steps:

[0012] S21. By weight, mix 20-25 parts deionized water, 10-15 parts anhydrous ethanol, 0.5-0.7 parts hexadecyltrimethylammonium bromide and 0.3-0.5 parts polyethylene glycol-600 and stir for 10-20 minutes to obtain a preliminary mixture;

[0013] S22. Slowly add 5-6 parts of modifier and 0.2-0.4 parts of ammonia to the preliminary mixture obtained in step S21 at a rotation speed of 450-500 r / min to obtain the secondary mixture;

[0014] S23. The secondary mixture obtained in step S22 is aged in a water bath at 35-40℃ at a rotation speed of 200-250r / min for 2-4h to finally obtain the modified carrier precursor.

[0015] Preferably, the preparation of the modified solvent includes the following steps:

[0016] S11. By mass, mix 70-80 parts of ethylene glycol and 8-10 parts of deionized water at a speed of 250-300 r / min for 10-15 min to obtain a preliminary solvent;

[0017] S12. Add 0.1-0.3 parts of cobalt chloride hexahydrate, 0.1-0.15 parts of nickel chloride hexahydrate and 0.5-1 parts of trisodium citrate to the preliminary solvent obtained in step S11, and stir for 20-30 minutes to obtain the solvent for the second step;

[0018] S13. Add 3-4 parts of thiourea to the solvent obtained in step S12, and continue stirring at 400-450 r / min for 40-50 min under water bath conditions at 38-42℃ to obtain the modified solvent.

[0019] Preferably, the preparation of the modified reinforcing agent includes the following steps:

[0020] S221. By weight, mix 1-2 parts tetraisopropyl titanate and 1-1.5 parts acetylacetone at a speed of 200-250 r / min for 20-30 min, then add 25-30 parts anhydrous ethanol and stir until homogeneous.

[0021] S222. Add 2-3 parts of tetraethyl orthosilicate and 0.5-1 parts of zinc nitrate hexahydrate to the sol obtained in step S221, disperse by ultrasonication for 20-30 min, add 0.5-1 parts of ammonia water dropwise, stir at 150-200 r / min for 2-4 h, and then dry at 60℃ for 20-24 h to obtain a light yellow solid;

[0022] S223. The pale yellow solid obtained in step S222 is placed in a tube furnace for segmented heating treatment. After naturally cooling to room temperature, it is washed 1-2 times with dilute hydrochloric acid and then washed with deionized water until neutral. It is then dried at 80°C for 10-12 hours to finally obtain the modified reinforcing agent.

[0023] Preferably, the centrifugation speed in step S3 is 7000-8000 rpm.

[0024] Preferably, in step S21, the mixing and stirring are carried out under water bath conditions at 35-40℃, and the rotation speed is 150-200 r / min.

[0025] Preferably, in step S12, the stirring is carried out in a water bath at 38-42℃, and the stirring speed is 450-500 r / min.

[0026] Preferably, the frequency of ultrasonic dispersion in step S222 is 40 kHz.

[0027] Preferably, the segmented heating in step S223 is as follows: the temperature is increased from room temperature to 350°C at a rate of 2°C / min, held for 1 hour, and then increased to 700°C at a rate of 5°C / min, held for 2 hours.

[0028] Application of a modified metal sulfide catalyst for the co-conversion of acidic natural gas in the catalytic co-conversion of acidic natural gas.

[0029] Compared with the prior art, the beneficial effects of the present invention are:

[0030] 1. This invention utilizes concentrated light technology to synergistically apply light and heat energy to the reaction system, achieving highly efficient conversion at a lower temperature (450-550℃) and normal pressure compared to traditional thermocatalysis, significantly reducing energy consumption. It is the first to design a metal sulfide composite catalyst system for the concentrated photocatalytic co-conversion of CH4 and H2S, converting two harmful / low-value gases into high-value CS2 and clean H2 in one step, realizing "waste treatment with waste" and resource recovery.

[0031] 2. This invention utilizes the synergistic effect of modified carrier precursors and modifiers to form a stable structure, providing robust skeletal support for the catalyst and preventing structural collapse during the reaction. Simultaneously, it enhances the absorption of visible and infrared light, promotes the separation and utilization of photogenerated electron-hole pairs, and improves the photothermal synergistic catalytic efficiency.

[0032] 3. This invention inhibits the sintering, loss or sulfur poisoning of active components through the synergistic effect of modified solvent, modified support precursor and modified reinforcing agent, and prolongs the service life of catalyst. It constructs an integrated structure of "highly dispersed active component-porous support-stable reinforcing framework", which enables the catalyst to exhibit high activity and high selectivity in the co-conversion of CH4 and H2S under concentrated light conditions. Attached Figure Description

[0033] Figure 1 is a process flow diagram of the preparation of the modified metal sulfide catalyst for the co-conversion of acidic natural gas according to the present invention;

[0034] Figure 2 is a process flow diagram of the preparation of the modified solvent of the present invention;

[0035] Figure 3 is a process flow diagram of the preparation of the modified carrier precursor of the present invention;

[0036] Figure 4 is a process flow diagram of the preparation of the modified reinforcing agent of the present invention;

[0037] Figure 5 is a TEM image of the modified metal sulfide catalyst obtained in Example 1 of the present invention at 200 nm.

[0038] Figure 6 is a TEM image of the modified metal sulfide catalyst obtained in Example 1 of the present invention at 100 nm.

[0039] Figure 7 is a TEM image of the modified metal sulfide catalyst obtained in Example 1 of the present invention at 50 nm.

[0040] Figure 8 is a TEM image of the modified metal sulfide catalyst obtained in Example 1 of the present invention at 5 nm.

[0041] Figure 9 is a line graph showing the CS2 yield of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention.

[0042] Figure 10 is a line graph showing the H2 yield of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention.

[0043] Figure 11 is a line graph showing the H2S conversion rate of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention.

[0044] Figure 12 is a line graph showing the CH4 conversion rate of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0045] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0046] Please refer to Figures 1-12. This invention provides a technical solution:

[0047] Example 1

[0048] A method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas:

[0049] Before preparing the modified metal sulfide catalyst, the modifying agent, modifying solvent, and modified support precursor are prepared first:

[0050] The preparation of the modified reinforcing agent includes the following steps:

[0051] S221. Mix 1g tetraisopropyl titanate and 1g acetylacetone at 200r / min for 20min, then add 25g anhydrous ethanol and stir until homogeneous.

[0052] S222. Add 2g of tetraethyl orthosilicate and 0.5g of zinc nitrate hexahydrate to the sol obtained in step S221, disperse it ultrasonically at a frequency of 40kHz for 20min, then add 0.5g of ammonia water dropwise, stir at a speed of 150r / min for 2h, and then dry at 60℃ for 20h to obtain a light yellow solid.

[0053] S223. The pale yellow solid obtained in step S222 is placed in a tube furnace for segmented heating (heated from room temperature to 350℃ at a rate of 2℃ / min, held for 1h, then heated to 700℃ at a rate of 5℃ / min, held for 2h). After naturally cooling to room temperature, it is washed once with dilute hydrochloric acid and then washed with deionized water until neutral. It is then dried at 80℃ for 10h to finally obtain the modified reinforcing agent.

[0054] The preparation of the modified solvent includes the following steps:

[0055] S11. Mix 70g of ethylene glycol and 8g of deionized water at 250r / min for 10min to obtain a preliminary solvent;

[0056] S12. Add 0.1g cobalt chloride hexahydrate, 0.1g nickel chloride hexahydrate and 0.5g trisodium citrate to the preliminary solvent obtained in step S11, and stir at 450r / min for 20min in a water bath at 38℃ to obtain the secondary solvent.

[0057] S13. Add 3g of thiourea to the solvent obtained in step S12, and continue stirring at 400r / min for 40min in a water bath at 38℃ to obtain the modified solvent.

[0058] The preparation of the modified carrier precursor includes the following steps:

[0059] S21. Mix 20g deionized water, 10g anhydrous ethanol, 0.5g cetyltrimethylammonium bromide and 0.3g polyethylene glycol-600 in a water bath at 35℃ and a speed of 150r / min for 10min to obtain a preliminary mixture;

[0060] S22. Slowly add 5g of modifier and 0.2g of ammonia to the preliminary mixture obtained in step S21 at a rotation speed of 450r / min to obtain the secondary mixture;

[0061] S23. The secondary mixture obtained in step S22 is aged in a water bath at 35°C at a rotation speed of 200 r / min for 2 h to finally obtain the modified carrier precursor.

[0062] The preparation of modified metal sulfide catalysts includes the following steps:

[0063] S1. Dissolve 0.8g of ammonium molybdate tetrahydrate in 70g of modified solvent and stir until completely dissolved to obtain a transparent and homogeneous solution;

[0064] S2. Add 2g of modified carrier precursor to the solution obtained in step S1 and transfer it to a polytetrafluoroethylene-lined autoclave, and react at 170°C for 22h.

[0065] S3. The solution after the reaction in step S2 is centrifuged at 7000 rpm for 8 min. The precipitate is washed twice with deionized water and anhydrous ethanol, respectively. After drying and grinding, the modified metal sulfide catalyst is obtained.

[0066] Example 2

[0067] A method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas:

[0068] Before preparing the modified metal sulfide catalyst, the modifying agent, modifying solvent, and modified support precursor are prepared first:

[0069] The preparation of the modified reinforcing agent includes the following steps:

[0070] S221. Mix 2g tetraisopropyl titanate and 1.5g acetylacetone at 250r / min for 30min, then add 30g anhydrous ethanol and stir until homogeneous.

[0071] S222. Add 3g of tetraethyl orthosilicate and 1g of zinc nitrate hexahydrate to the sol obtained in step S221, disperse it ultrasonically at a frequency of 40kHz for 30min, add 1g of ammonia water dropwise, stir at a speed of 200r / min for 4h, and then dry at 60℃ for 24h to obtain a light yellow solid.

[0072] S223. The pale yellow solid obtained in step S222 is placed in a tube furnace for segmented heating (heated from room temperature to 350℃ at a rate of 2℃ / min, held for 1h, then heated to 700℃ at a rate of 5℃ / min, held for 2h). After naturally cooling to room temperature, it is washed twice with dilute hydrochloric acid and then washed with deionized water until neutral. It is then dried at 80℃ for 12h to finally obtain the modified reinforcing agent.

[0073] The preparation of the modified solvent includes the following steps:

[0074] S11. Mix 80g of ethylene glycol and 10g of deionized water at 300r / min for 15min to obtain a preliminary solvent;

[0075] S12. Add 0.3g cobalt chloride hexahydrate, 0.15g nickel chloride hexahydrate and 1g trisodium citrate to the preliminary solvent obtained in step S11, and stir at 500r / min for 30min in a water bath at 42℃ to obtain the secondary solvent.

[0076] S13. Add 4g of thiourea to the solvent obtained in step S12, and continue stirring at 450r / min for 50min in a water bath at 42℃ to obtain the modified solvent.

[0077] The preparation of the modified carrier precursor includes the following steps:

[0078] S21. Mix 25g deionized water, 15g anhydrous ethanol, 0.7g cetyltrimethylammonium bromide and 0.5g polyethylene glycol-600 in a water bath at 40℃ and a speed of 200r / min for 20min to obtain a preliminary mixture;

[0079] S22. Slowly add 6g of modifier and 0.4g of ammonia to the preliminary mixture obtained in step S21 at a rotation speed of 500r / min to obtain the secondary mixture;

[0080] S23. The secondary mixture obtained in step S22 is aged in a water bath at 40°C at a rotation speed of 250 r / min for 4 h to finally obtain the modified carrier precursor.

[0081] The preparation of modified metal sulfide catalysts includes the following steps:

[0082] S1. Dissolve 1.2g of ammonium molybdate tetrahydrate in 80g of modified solvent and stir until completely dissolved to obtain a transparent and homogeneous solution;

[0083] S2. Add 3g of modified carrier precursor to the solution obtained in step S1 and transfer it to a polytetrafluoroethylene-lined autoclave, and react at 180°C for 24h.

[0084] S3. The solution after the reaction in step S2 is centrifuged at 8000 rpm for 10 min. The precipitate is washed three times with deionized water and anhydrous ethanol, respectively. After drying and grinding, the modified metal sulfide catalyst is obtained.

[0085] Example 3

[0086] A method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas:

[0087] Before preparing the modified metal sulfide catalyst, the modifying agent, modifying solvent, and modified support precursor are prepared first:

[0088] The preparation of the modified reinforcing agent includes the following steps:

[0089] S221. Mix 1.5g tetraisopropyl titanate and 1.2g acetylacetone at 220r / min for 25min, then add 27g anhydrous ethanol and stir until homogeneous.

[0090] S222. Add 2.5g of tetraethyl orthosilicate and 0.8g of zinc nitrate hexahydrate to the sol obtained in step S221, disperse it ultrasonically at a frequency of 40kHz for 25min, add 0.7g of ammonia water dropwise, stir at a speed of 170r / min for 3h, and then dry at 60℃ for 22h to obtain a light yellow solid.

[0091] S223. The pale yellow solid obtained in step S222 is placed in a tube furnace for segmented heating (heated from room temperature to 350℃ at a rate of 2℃ / min, held for 1h, then heated to 700℃ at a rate of 5℃ / min, held for 2h). After naturally cooling to room temperature, it is washed once with dilute hydrochloric acid and then washed with deionized water until neutral. It is then dried at 80℃ for 11h to finally obtain the modified reinforcing agent.

[0092] The preparation of the modified solvent includes the following steps:

[0093] S11. Mix 75g of ethylene glycol and 9g of deionized water at a speed of 230r / min for 13min to obtain a preliminary solvent;

[0094] S12. Add 0.2g cobalt chloride hexahydrate, 0.13g nickel chloride hexahydrate and 0.7g trisodium citrate to the preliminary solvent obtained in step S11, and stir at 480r / min for 25min under a water bath at 40℃ to obtain the secondary solvent.

[0095] S13. Add 3.5g of thiourea to the solvent obtained in step S12, and continue stirring at 420r / min for 45min under 40℃ water bath conditions to obtain the modified solvent.

[0096] The preparation of the modified carrier precursor includes the following steps:

[0097] S21. Mix 23g of deionized water, 12g of anhydrous ethanol, 0.6g of cetyltrimethylammonium bromide and 0.4g of polyethylene glycol-600 in a water bath at 38°C and at a speed of 160r / min for 15min to obtain a preliminary mixture.

[0098] S22. Slowly add 5.5g of modifier and 0.3g of ammonia to the preliminary mixture obtained in step S21 at a rotation speed of 480r / min to obtain the secondary mixture;

[0099] S23. The secondary mixture obtained in step S22 is aged in a water bath at 38°C at a rotation speed of 240 r / min for 3 h to finally obtain the modified carrier precursor.

[0100] The preparation of modified metal sulfide catalysts includes the following steps:

[0101] S1. Dissolve 1g of ammonium molybdate tetrahydrate in 75g of modified solvent and stir until completely dissolved to obtain a transparent and homogeneous solution;

[0102] S2. Add 2.5g of modified carrier precursor to the solution obtained in step S1 and transfer it to a polytetrafluoroethylene-lined autoclave, and react at 175°C for 23h.

[0103] S3. The solution after the reaction in step S2 is centrifuged at 7500 rpm for 9 min. The precipitate is washed three times with deionized water and anhydrous ethanol, respectively. After drying and grinding, the modified metal sulfide catalyst is obtained.

[0104] Comparative Example 1

[0105] The only difference between Comparative Example 1 and Example 1 is that no modifier was added in this comparative example; the other steps are exactly the same in Comparative Example 1 and Example 1.

[0106] Comparative Example 2

[0107] The only difference between Comparative Example 2 and Example 1 is that no modified solvent was added in this comparative example; the other steps are exactly the same in Comparative Example 2 and Example 1.

[0108] Comparative Example 3

[0109] The only difference between Comparative Example 3 and Example 1 is that no modified carrier precursor was added in this comparative example; the other steps are exactly the same in Comparative Example 3 and Example 1.

[0110] Performance testing:

[0111] Figures 5-8 are TEM images of the modified metal sulfide catalyst obtained in Example 1 of this invention at 200, 100, 50, and 5 nm, respectively. The figures confirm that the metal nanoparticles are uniformly distributed on the support surface, with a particle size controlled within the range of 1-10 nm, and no obvious agglomeration.

[0112] The present invention sets up a performance testing experiment in which the co-conversion reaction of CH4 and H2S is carried out in a quartz tubular reactor with an internal catalyst bed, simulating sunlight, and the light intensity is set at 3.67 W / cm². 2 The reaction temperature was 793.15 K, the reactant gases were CH4 and H2S in a volume ratio of 1:2, and the total gas hourly space velocity (GHSV) was controlled at 2000-3000 h⁻¹. -1 The product composition was analyzed using online gas chromatography (GC). The conversion rates of CH4, H2S, H2, and CS2 were tested using the system, and the data are shown in Table 1 below.

[0113] Table 1

[0114]

[0115] Figure 9 is a line graph showing the CS2 yield of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention; Figure 10 is a line graph showing the H2 yield of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention; Figure 11 is a line graph showing the H2S conversion of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention; and Figure 12 is a line graph showing the CH4 conversion of the modified metal sulfide catalysts obtained in Example 1 and Comparative Example 1 of the present invention. As can be seen from Table 1 and Figures 9-12, the catalytic activity of the modified metal sulfide catalysts obtained in the examples for the co-conversion of acidic natural gas is superior to that in the comparative example. This indicates that the synergistic effect of the modifier, modified solvent, and modified support precursor effectively improves the catalytic performance, enabling the catalysts to exhibit high activity and high selectivity for the co-conversion of CH4 and H2S under concentrated light conditions.

[0116] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas, characterized in that, The preparation steps include: S1. Dissolve 0.8-1.2 parts by mass of ammonium molybdate tetrahydrate in 70-80 parts of modified solvent and stir until completely dissolved to obtain a transparent and homogeneous solution; S2. Add 2-3 parts of the modified support precursor to the solution obtained in step S1 and transfer it to a polytetrafluoroethylene-lined autoclave. React at 170-180℃ for 22-24 hours. S3. Centrifuge the solution after reaction in step S2 for 8-10 minutes. Wash the precipitate 2-3 times with deionized water and anhydrous ethanol, respectively. After drying and grinding, obtain the modified metal sulfide catalyst. The preparation of the modified support precursor includes the following steps: S21. Mix and stir 20-25 parts of deionized water, 10-15 parts of anhydrous ethanol, 0.5-0.7 parts of hexadecyltrimethylammonium bromide and 0.3-0.5 parts of polyethylene glycol-600 for 10- S21. After 20 minutes, a preliminary mixture is obtained; S22. At a rotation speed of 450-500 r / min, 5-6 parts of the modifier and 0.2-0.4 parts of ammonia are slowly added to the preliminary mixture obtained in step S21 to obtain a secondary mixture; S23. The secondary mixture obtained in step S22 is aged in a water bath at 35-40℃ at a rotation speed of 200-250 r / min for 2-4 hours to finally obtain the modified carrier precursor; The preparation of the modified solvent includes the following steps: S11. By mass, 70-80 parts of ethylene glycol and 8-10 parts of deionized water are mixed and stirred at a rotation speed of 250-300 r / min for 10-15 minutes to obtain a preliminary solvent; S24.

12. Add 0.1-0.3 parts of cobalt chloride hexahydrate, 0.1-0.15 parts of nickel chloride hexahydrate, and 0.5-1 parts of trisodium citrate to the preliminary solvent obtained in step S11, and stir for 20-30 min to obtain the secondary solvent; S13. Add 3-4 parts of thiourea to the secondary solvent obtained in step S12, and continue stirring at 400-450 r / min for 40-50 min under a water bath at 38-42℃ to obtain the modified solvent; the preparation of the modified reinforcing agent includes the following steps: S221. By mass, mix 1-2 parts of tetraisopropyl titanate and 1-1.5 parts of acetylacetone by stirring at 200-250 r / min for 20 min. -30 min later, add 25-30 parts of anhydrous ethanol and stir evenly; S222. Add 2-3 parts of tetraethyl orthosilicate and 0.5-1 parts of zinc nitrate hexahydrate to the sol obtained in step S221, sonicate for 20-30 min, then add 0.5-1 parts of ammonia water dropwise, stir at 150-200 r / min for 2-4 h, and then dry at 60℃ for 20-24 h to obtain a light yellow solid; S223. Place the light yellow solid obtained in step S222 in a tube furnace for segmented heating treatment, cool naturally to room temperature, wash 1-2 times with dilute hydrochloric acid, then wash with deionized water until neutral, and dry at 80℃ for 10-12 h to finally obtain the modified reinforcing agent.

2. The method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas according to claim 1, characterized in that, The centrifugation speed in step S3 is 7000-8000 rpm.

3. The method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas according to claim 1, characterized in that, In step S21, the mixing and stirring are carried out in a water bath at 35-40℃ with a rotation speed of 150-200 r / min.

4. The method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas according to claim 1, characterized in that, In step S12, the stirring is carried out in a water bath at 38-42℃, and the stirring speed is 450-500 r / min.

5. The method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas according to claim 1, characterized in that, In step S222, the frequency of ultrasonic dispersion is 40 kHz.

6. The method for preparing a modified metal sulfide catalyst for the co-conversion of acidic natural gas according to claim 1, characterized in that, The segmented heating in step S223 is as follows: the temperature is increased from room temperature to 350℃ at a rate of 2℃ / min, and held for 1 hour, and then increased to 700℃ at a rate of 5℃ / min, and held for 2 hours.

7. The application of a modified metal sulfide catalyst prepared by the preparation method according to any one of claims 1-6 for the synergistic catalytic conversion of acidic natural gas in the photothermal synergistic catalytic conversion of CH4 and H2S into CS2 and H2.

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