Preparation method of coal gasification fine slag derived Co3O4 (at) Z-ZIS catalyst for preparing methyl formate by co-conversion of CO2 and methanol through photo-thermal catalysis

Abstract

The invention discloses a preparation method of a Co3O4 (at) Z-ZIS catalyst for preparing methyl formate by co-conversion of CO2 and methanol through photo-thermal catalysis. Gasification fine slag generated after coal gasification is subjected to drying, screening, acid pickling, water washing, drying, alkaline leaching, water washing and drying processes to synthesize Na-P1 type zeolite. The preparation method comprises the following steps: growing indium zinc sulfide on Na-P1 type zeolite in situ by adopting a hydrothermal method, and loading Co metal oxide by adopting the hydrothermal method to finally prepare the novel efficient photo-thermal catalyst Co3O4 (at) Z-ZIS. Compared with the existing industrial catalyst, the catalyst Co3O4 (at) Z-ZIS shows excellent photo-thermal catalytic performance under the mild conditions of normal pressure and lower temperature. When the catalyst is applied to a reaction for preparing methyl formate through partial oxidative dehydrogenation of methanol in a CO2 atmosphere, the catalytic efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a coal gasification fine slag catalyst, and belongs to the field of waste resource recycling, in particular to a preparation method of a coal gasification fine slag derived Co3O4@Z-ZIS catalyst for preparing methyl formate through photocatalytic co-conversion of CO2 and methanol. BACKGROUND

[0002] Gasification slag is a byproduct of the gasification process, including fine slag (FS) from the filter and coarse slag (CS) from the lock hopper. Using landfill to store or dispose of the slag will seep into the soil and pollute water sources, and because the slag contains various heavy metals, it has caused serious harm to human health and the natural environment. In addition, the nanoparticles in the coal gasification slag can be inhaled by the human body, causing the immune system to weaken. Therefore, the rapid growth of the annual output of coal gasification slag poses a huge challenge to its environmental harmless treatment, and controlling its pollution has become an urgent problem.

[0003] The main components of coal gasification fine slag are silicon (SiO2, content 40%-60%) and aluminum (Al2O3, content 15%-25%), and the core structure of zeolite is exactly a silicate-aluminate framework, and the components are highly compatible, without the need for additional large amounts of high-purity silicon source and aluminum source. Even part of the residual carbon can be burned in the pretreatment stage to provide auxiliary heat for the reaction, further reducing energy consumption, directly reducing the complexity and cost of raw material preparation from the composition. In the gasification process, due to high-temperature reaction and gas flow impact, coal gasification fine slag naturally forms a micrometer-sized particle structure with hollow or porous structure, and the specific surface area is high (usually 50-150 m 2 / g) by itself. This pre-existing porous structure can become a "skeleton template" for crystal growth in the subsequent synthesis of zeolite, helping the zeolite to form a microporous-mesoporous composite structure more quickly without the need for additional complex processes to construct pores. The specific surface area of the finally prepared zeolite can be increased to 300-500 m 2 / g.

[0004] Methanol is an important energy-containing platform molecule in the chemical industry. In the field of C1 chemistry, methanol is used as a raw material to produce aldehydes, ethers, alcohols, esters, olefins and other chemical products. Using methanol as fuel can reduce carbon dioxide emissions and air pollution. With the rapid development of coal-to-methanol (CTM) industry, the total methanol production will increase from 110 million tons in 2018 to 220 million tons in 2030. However, the demand for traditional methanol downstream products is low, mainly formaldehyde, dimethyl ether and methyl tertiary butyl ether (MTBE), so it is urgent to convert methanol into higher value-added chemicals.

[0005] Methyl formate (MF) is an important downstream product of methanol, which can be used to produce more than fifty important chemicals such as ethylene glycol, N,N-dimethylformamide and formamide. Therefore, the route from methanol to MF to other chemicals is not only a promising route for current chemical production, but also for the future. MF can be obtained in industry by esterification, carbonylation or dehydrogenation of methanol. The esterification process has been discontinued due to large raw material consumption, equipment corrosion and environmental problems. Carbonylation is still working in industry. However, high working pressure, easy hydrolysis of sodium methoxide catalyst and equipment corrosion resulting therefrom are inherent difficulties of this process. Methanol dehydrogenation to MF, including oxidative dehydrogenation and direct dehydrogenation, has attracted wide attention in the past decades compared with carbonylation process due to its relatively moderate reaction conditions. Methanol conversion is usually high in oxidative dehydrogenation method, and hydrogen gas, a green energy, is produced. Therefore, methanol oxidative dehydrogenation to MF has been widely and deeply studied. SUMMARY

[0006] The purpose of the present application is to solve the problems of easy corrosion of existing catalysts, large reaction pressure and the resulting problems.

[0007] One kind of coal gasification fine slag derived Co3O4@Z-ZIS catalyst for photo-thermal catalytic CO2 and methanol co-conversion to prepare methyl formate, comprising the following steps:

[0008] (1) After the coal gasification fine slag is passed through a 180 mesh sieve, drying treatment is carried out to obtain coal gasification fine slag powder;

[0009] (2) After the coal gasification fine slag powder is added to a hydrochloric acid solution for pickling treatment, water washing and drying, it is added to a NaOH solution for alkali leaching, water washing and drying treatment, to obtain Na-P1 type zeolite;

[0010] (3) The NaP1 type zeolite synthesized in step 2) is weighed, a zinc source and an indium source are dissolved in deionized water and stirred vigorously, a surfactant is added and stirred again, and then a sulfur source is added and stirred until dissolved, transferred to a hydrothermal kettle for hydrothermal reaction, and finally centrifuged, washed and dried to obtain a yellow-black solid;

[0011] (4) The solid synthesized in step 3) is weighed, a cobalt source is dissolved in deionized water and stirred vigorously, transferred to a hydrothermal kettle for hydrothermal reaction, and finally centrifuged, washed and dried to obtain a gray-black solid Co3O4@Z-ZIS catalyst.

[0012] Preferably, the concentration of hydrochloric acid in step 2) is 1 mol / L, and the concentration of NaOH solution is 2 mol / L. The ratio of coal gasification fine slag powder to hydrochloric acid is 1g:20mL, and the ratio to NaOH solution is 1g:20mL. The temperature of acid washing is 85°C, the stirring speed is 1000rpm, and the stirring time is 4h. The temperature of alkali leaching is 90°C, the stirring speed is 1000rpm, and the stirring time is 10h.

[0013] Preferably, the zinc source in step 3) is Zn(NO3)2·6H2O, the indium source is InCl3, the surfactant is CTAB, and the sulfur source is thioacetamide.

[0014] Preferably, the mass ratio of NaP1 type zeolite in the mixed solution in step 3) is 5-15%, the mass ratio of the zinc source is 14-17%, the mass ratio of the indium source is 30-34%, and the mass ratio of the sulfur source is 29-32%.

[0015] Preferably, the vigorous stirring in step 3) is 700rpm for 2h.

[0016] Preferably, the hydrothermal reaction temperature in step 3) is 160°C for 16h.

[0017] Preferably, the drying temperature in steps 2), 3), and 4) is 60°C, and the vacuum oven drying is 12h.

[0018] Preferably, the cobalt source in step 4) is Co(NO3)2·6H2O, and the mass ratio is 90-95%.

[0019] Preferably, the vigorous stirring in step 4) is 700rpm for 0.5h.

[0020] Preferably, the hydrothermal reaction temperature in step 4) is 180°C for 12h.

[0021] II. Performance test of Co3O4@Z-ZIS catalyst for photo-thermal catalytic methanol to methyl formate Test method: First, 1-3mg of the catalyst with a cobalt source mass ratio of 90-95% is added to the photo-thermal reactor, then 10mL of methanol is added, and CO2 is bubbled in the suspension for 10min to exhaust the air in the reactor and saturate the CO2 in the reactor. The reactor is sealed and allowed to react at a temperature of 80-140°C, a rotation speed of 300rpm, and a 300W xenon lamp irradiation for 1-4h. Test results: Among all the catalysts studied, the catalyst loaded with a cobalt source mass ratio of 93% showed the highest catalytic activity, and the generation rate of product MF reached 6.9mmol·g -1 ·h -1 .

[0022] The test results show that the Co3O4@Z-ZIS catalyst prepared in the application has excellent performance in the production of methyl formate by methanol oxidation dehydrogenation in a CO2 atmosphere, and improves the yield of methyl formate while expanding the high-value utilization of coal gasification waste residue. BRIEF DESCRIPTION OF DRAWINGS Figure 1 The photo-thermal catalytic methanol production rate of methyl formate of the Co3O4@Z-ZIS catalyst prepared for the application examples 1-5 at different temperatures, different catalyst dosages, different reaction times and different cobalt source mass ratios. Figure 2 The photo-thermal catalytic methanol production rate of methyl formate of the different catalysts (comparative examples 1-3) obtained by the application. DETAILED DESCRIPTION

[0023] Example 1 The coal gasification fine slag was dried after being sieved through a 180-mesh screen to obtain coal gasification fine slag powder. The coal gasification fine slag powder was added to a hydrochloric acid solution with a concentration of 1 mol / L, and the ratio of the coal gasification fine slag powder to the hydrochloric acid was 1 g:20 mL. After acid washing, the mixture was washed with distilled water three times, dried in a vacuum oven at 60°C for 12 h, and then added to a sodium hydroxide solution with a concentration of 2 mol / L at a ratio of 1 g:20 mL. The mixture was stirred at 90°C for 10 h for alkali leaching, washed with distilled water three times, and dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O and 624 mg of InCl3 were dissolved in 50 mL of water and stirred vigorously for 30 min. Then 230 mg of CTAB was added and stirring was continued for 1 h. 604 mg of thioacetamide was weighed into the above dispersion and stirring was continued until the thioacetamide was dissolved. The mixture was transferred to a 100 mL high-pressure reaction sign and kept in an environment of 160°C for 16 h. After natural cooling to room temperature, the mixture was washed with ethanol and distilled water three times and dried in a vacuum at 60°C for 12 h. 1.164 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS were dissolved in 60 mL of water and stirred vigorously for 30 min. Then the mixture was transferred to a 100 mL high-pressure reaction sign and kept in an environment of 180°C for 12 h. After natural cooling to room temperature, the mixture was washed with distilled water three times and dried in a vacuum at 60°C for 12 h to obtain gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of catalyst with a cobalt source mass ratio of 92% was added to the photo-thermal reaction kettle, followed by the addition of 10 mL of methanol. CO2 was then bubbled in the suspension for 10 min to exhaust the air in the reaction kettle and saturate the amount of CO2 in the kettle. The reactor was sealed and allowed to react at a temperature of 110°C, a rotation speed of 300 rpm and a 300W xenon lamp irradiation for 1 h.

[0024] Example 2 The fine coal gasification slag was passed through an 180-mesh sieve and dried to obtain fine coal gasification slag powder. The fine coal gasification slag powder was added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h. Then, it was added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 200 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, and then transfer it to a 100 mL high-pressure reactor and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water and dry in a vacuum at 60 °C for 12 h. Weigh 1.746 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL high-pressure reactor and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 2 mg of a cobalt source catalyst (94% by mass) was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0025] Example 3 The fine coal gasification slag was passed through an 180-mesh sieve and dried to obtain fine coal gasification slag powder. The fine coal gasification slag powder was added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h. Then, it was added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, transfer it to a 100 mL high-pressure reactor, and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. Weigh 2.328 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL high-pressure reactor and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of a cobalt source catalyst (96% by mass) was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 100°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0026] Example 4 The fine coal gasification slag was passed through an 180-mesh sieve and dried to obtain fine coal gasification slag powder. The fine coal gasification slag powder was added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h. Then, it was added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 300 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, transfer it to a 100 mL high-pressure reactor, and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. Weigh 1.746 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL high-pressure reactor and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of a cobalt source catalyst (94% by mass) was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 2 hours at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0027] Example 5 The fine coal gasification slag was passed through an 180-mesh sieve and dried to obtain fine coal gasification slag powder. The fine coal gasification slag powder was added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h. Then, it was added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it was dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, transfer it to a 100 mL high-pressure reactor, and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. Weigh 1.746 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL high-pressure reactor and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of a cobalt source catalyst (94% by mass) was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0028] Comparative Example 1 Similar to Example 5, except that step 4) is missing. After passing the coal gasification fine slag through an 180-mesh sieve, the coal gasification fine slag powder is obtained. The coal gasification fine slag powder is added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h. Then, it is added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, and stir continuously until the thioacetamide dissolves. Transfer the solution to a 100 mL high-pressure reactor and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. First, 1 mg of catalyst was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge the air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0029] Comparative Example 2 Similar to Example 5, except that in step 5), the cobalt source is cobalt chloride. The fine coal gasification slag is passed through an 180-mesh sieve and then dried to obtain fine coal gasification slag powder. The fine coal gasification slag powder is added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h. Then, it is added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 230 mg of CTAB and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, transfer it to a 100 mL high-pressure reactor, and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. Weigh 1.427 g of CoCl2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL high-pressure reactor and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of catalyst was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge the air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

[0030] Comparative Example 3 Same as Example 6, except that in step 3), the surfactant is SDBS. The coal gasification fine slag is passed through an 180-mesh sieve and dried to obtain coal gasification fine slag powder. The coal gasification fine slag powder is added to a 1 mol / L hydrochloric acid solution at a ratio of 1 g: 20 mL for acid washing. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h. Then, it is added to a 2 mol / L NaOH solution at a ratio of 1 g: 20 mL and stirred at 90°C for 10 h for alkali leaching. After washing with distilled water three times, it is dried in a vacuum oven at 60°C for 12 h to obtain Na-P1 type zeolite. Weigh 100 mg of NaP1 type zeolite, 304 mg of Zn(NO3)2·6H2O, and 624 mg of InCl3, dissolve them in 50 mL of water, and stir vigorously for 30 min. Then add 220 mg of SDBS and continue stirring for 1 h. Weigh 604 mg of thioacetamide into the above dispersion, stir continuously until the thioacetamide dissolves, transfer it to a 100 mL autoclave, and maintain it at 160 °C for 16 h. After naturally cooling to room temperature, wash three times with ethanol and distilled water, and dry in a vacuum at 60 °C for 12 h. Weigh 1.746 g of Co(NO3)2·6H2O and 60 mg of Z-ZIS, dissolve them in 60 mL of water, and stir vigorously for 30 min. Then transfer it to a 100 mL autoclave and maintain it at 180 °C for 12 h. After naturally cooling to room temperature, the catalyst was washed three times with distilled water and dried in a vacuum at 60°C for 12 hours to obtain a gray-black solid Co3O4@Z-ZIS catalyst. First, 1 mg of catalyst was added to the photothermal reactor, followed by 10 mL of methanol. CO2 was then bubbled in the suspension for 10 minutes to purge the air from the reactor and saturate it with CO2. The reactor was then sealed and allowed to react for 1 hour at 110°C, 300 rpm, and under 300 W xenon lamp irradiation.

Claims

1. A method for preparing a Co3O4@Z-ZIS catalyst derived from coal gasification fine slag for photothermal catalytic co-conversion of CO2 and methanol to methyl formate, comprising the following steps: (1) After passing the coal gasification fine slag through an 80-180 mesh sieve, dry it to obtain coal gasification fine slag powder for later use. (2) The coal gasification fine slag powder is added to hydrochloric acid solution for acid washing, then washed with water and dried. Then it is added to NaOH solution for alkaline leaching, water washing and drying to obtain Na-P1 type zeolite. (3) Weigh the NaP1 type zeolite synthesized in step 2), add zinc source and indium source to dissolve in deionized water and stir vigorously, add surfactant and stir vigorously again, add sulfur source and continue stirring until dissolved, transfer to hydrothermal reactor for hydrothermal reaction, and finally centrifuge, wash and dry to obtain yellow-black solid. (4) Weigh the solid synthesized in step 3), add cobalt source and dissolve in deionized water and stir vigorously. Transfer to a hydrothermal reactor for hydrothermal reaction, and finally centrifuge, wash and dry to obtain gray-black solid Co3O4@Z-ZIS catalyst.

2. The preparation method according to claim 1, characterized in that, In step 2), the concentration of hydrochloric acid is 0.5-1.5 mol / L, and the concentration of NaOH solution is 1-2 mol / L.

3. The preparation method according to claim 1, characterized in that, In step 2), the ratio of coal gasification fine slag powder to hydrochloric acid is 1g:20mL, and the ratio of it to NaOH solution is 1g:20mL.

4. The preparation method according to claim 1, characterized in that, In step 2), the pickling temperature is 80-100℃, the stirring speed is 800-1200 rpm, and the stirring time is 1-6 hours. The alkali leaching temperature is 80-100℃, the stirring speed is 800-1200 rpm, and the stirring time is 8-12 hours.

5. The preparation method according to claim 1, characterized in that, In step 3), the zinc source is zinc nitrate, zinc sulfate, or zinc chloride; the indium source is indium nitrate, indium sulfate, or indium chloride; the surfactant is CTAB or SDBS; and the sulfur source is thioacetamide, sodium sulfide, or sodium thiosulfate.

6. The preparation method according to claim 1, characterized in that, In step 3), the mass ratio of NaP1 type zeolite in the mixture is 5-15%, the mass ratio of zinc source is 14-17%, the mass ratio of indium source is 30-34%, and the mass ratio of sulfur source is 29-32%.

7. The preparation method according to claim 1, characterized in that, Step 3) involves vigorous stirring at 700 rpm for 1-4 hours, with a hydrothermal reaction temperature of 140-180℃ and a reaction time of 15-18 hours.

8. The preparation method according to claim 1, characterized in that, In steps 2), 3), and 4), the drying temperature is 60°C, and the drying is carried out in a vacuum oven for 12 hours.

9. The preparation method according to claim 1, characterized in that, In step 4), the cobalt source is Co(NO3)2·6H2O, with a mass ratio of 90-95%.

10. The preparation method according to claim 1, characterized in that, In step 4), the vigorous stirring is performed at 500-1000 rpm for 0.5-1 h, and the hydrothermal reaction temperature in step 4) is 160-200℃ for 12 h.

Images