Carbon dioxide hydrogenation synthesis methanol catalyst, its preparation method and application

Abstract

The application discloses a carbon dioxide hydrogenation synthesis methanol catalyst and a preparation method and application thereof, and belongs to the technical field of catalyst synthesis and fine chemical industry. The carbon dioxide hydrogenation synthesis methanol catalyst provided by the application is composed of sulfur-bridged atom-level dispersed molybdenum anchored by a nitrogen-containing porous material. The catalyst has the advantages of high active metal dispersion, synergistic effect between atom-level dispersed molybdenum active sites and pore enrichment effect of the nitrogen-containing porous material, and the like. In the catalytic effect, the carbon dioxide hydrogenation synthesis methanol process can be realized in a wide temperature and pressure range including normal temperature, and the problem of catalytic conversion of carbon dioxide into methanol under mild conditions can be solved. In addition, the catalyst shows excellent stability in the reaction process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalyst synthesis and fine chemical technology, and particularly relates to a carbon dioxide hydrogenation synthesis methanol catalyst, a preparation method and application thereof. BACKGROUND

[0002] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the general background of the application and does not necessarily pertain to the prior art that is already known to those of ordinary skill in the art.

[0003] At present, the process of CO2 hydrogenation to methanol still faces many challenges. First, CO2 is a molecule with high chemical inertness, and the activation of its carbon-oxygen double bond is difficult. Traditional CO2 hydrogenation to methanol process often needs to be carried out under harsh reaction conditions such as high temperature and high pressure (220-350℃, 5-10MPa), and the design of CO2 hydrogenation to methanol catalyst under mild conditions is challenging. In addition, CO2 hydrogenation to prepare methanol reaction involves a multi-step hydrogenation process, and the design of high-selectivity hydrogenation to methanol catalyst is challenging. At present, heterogeneous catalysts for catalytic CO2 hydrogenation to methanol mainly include Cu-based catalysts, noble metal-based catalysts and metal oxide or sulfide catalysts. Among them, Cu-based catalysts (such as Cu-ZnO-Al2O3 catalyst produced by ICI company) are the earliest developed and most in-depth studied catalyst system. In terms of catalytic activity, the conversion rate of traditional Cu-ZnO-Al2O3 catalyst under harsh reaction conditions of 220-300℃ and >5MPa is about 30%, and the CH3OH selectivity is about 30-70%, which is difficult to achieve high selectivity conversion under mild conditions; the introduction of noble metal can further moderate the operation conditions of carbon dioxide hydrogenation to methanol, but the selectivity of methanol is low. Metal oxide catalysts, such as In2O3, ZnO-ZrO2 solid solution disclosed in patents CN109420486A or CN114602449A, exhibit very excellent methanol selectivity in carbon dioxide hydrogenation to methanol catalytic reaction, but their catalytic activity is relatively low, and the operating conditions usually require high temperature and high pressure conditions of 300℃ and 5MPa or more. Metal sulfide catalysts, such as FL-MoS2 catalyst disclosed in patent CN113499787A, are a high-efficiency catalytic system developed in recent years, which can catalyze carbon dioxide hydrogenation to synthesize methanol under relatively mild reaction conditions (180℃, 5MPa), but its catalytic activity under normal temperature and low pressure conditions is relatively poor.

[0004] In summary of the above technical analysis, the current carbon dioxide hydrogenation to methanol catalyst still generally needs harsh operating conditions such as high temperature and high pressure. Therefore, it is of great practical significance and industrial value to develop a carbon dioxide hydrogenation to methanol catalyst under mild conditions. SUMMARY

[0005] In order to solve the problems in the prior art, the present application aims to provide a carbon dioxide hydrogenation synthesis methanol catalyst, a preparation method and application thereof. The catalyst provided by the present application can catalyze carbon dioxide hydrogenation to methanol in a wide temperature (including normal temperature) and pressure range, and has excellent stability.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] In a first aspect, the present application provides a carbon dioxide hydrogenation synthesis methanol catalyst, comprising a carrier and a catalytic component supported on the carrier. The carrier is a nitrogen-containing porous material, and the catalytic component is sulfur and molybdenum. The molybdenum is dispersed on the surface of the nitrogen-containing porous material carrier in an atomic level, and the content of molybdenum is 0.001wt.%-50wt.% of the total mass of the catalyst, and the content of sulfur is 0.001wt.%-50wt.% of the total mass of the catalyst.

[0008] The carbon dioxide hydrogenation synthesis methanol catalyst provided by the present application is composed of sulfur-bridged atomic-level dispersed molybdenum anchored by a nitrogen-containing porous material. The catalyst has the advantages of high active metal dispersion, synergistic effect between atomic-level dispersed molybdenum active sites, and pore enrichment effect of the nitrogen-containing porous material. In terms of catalytic effect, the catalyst can realize carbon dioxide hydrogenation to methanol in a wide temperature (including normal temperature) and pressure range, and is expected to solve the problem of catalytic conversion of carbon dioxide to methanol under mild conditions. Moreover, the catalyst exhibits excellent stability during the reaction process.

[0009] In some embodiments of the present application, the nitrogen-containing porous material is a covalent triazine framework material or a nitrogen-doped porous carbon material.

[0010] The specific surface area of the nitrogen-containing porous material is preferably 100-5000m 2 / g, and the nitrogen content is preferably 0.01-60wt.%, specifically 0.01wt.%, 0.5wt.%, 1wt.%, 2wt.%, 5wt.%, 10wt.%, 15wt.%, 20wt.%, 25wt.%, 30wt.%, 35wt.%, 40wt.%, 45wt.%, 50wt.%, 55wt.%, or 60wt.%. The nitrogen content refers to the percentage of nitrogen in the whole nitrogen-containing porous material. In the present application, the nitrogen content can be adjusted by the amount of nitrogen source used during preparation.

[0011] In a second aspect, the present application provides a preparation method of the carbon dioxide hydrogenation synthesis methanol catalyst of the first aspect, comprising the following steps:

[0012] Mixing a molybdenum source, a sulfur source, a nitrogen-containing porous material and a solvent, carrying out a solvothermal reaction, after the reaction, filtering, washing and drying the obtained mixed solution to obtain a catalyst precursor material;

[0013] Carrying out high-temperature reduction treatment on the catalyst precursor material in a reducing atmosphere to obtain a carbon dioxide hydrogenation synthesis methanol catalyst.

[0014] In some embodiments of the present application, the nitrogen-containing porous material is a covalent triazine framework material or a nitrogen-doped porous carbon material.

[0015] The preparation method of the covalent triazine framework material comprises the following steps:

[0016] After grinding and uniformly mixing the organic monomer and the zinc salt, baking at 380-420 DEG C under vacuum for 18-22 h, then increasing the temperature to 600-700 DEG C and baking for 18-22 h, grinding the product after baking and washing in an acid solution, then filtering, washing with deionized water, washing with tetrahydrofuran, and drying to obtain the covalent triazine framework material.

[0017] In some embodiments of the present application, the organic monomer is preferably one of 2,6-pyridine dicyanide, 7,7,8,8-tetracyanoquinodimethane or 1,4-dicyanobenzene; the zinc salt is preferably zinc chloride; and the molar ratio of the organic monomer to the zinc salt is preferably 1:1-1:10.

[0018] When the organic monomer is 2,6-pyridine dicyanide, preferably, after grinding and uniformly mixing 2,6-pyridine dicyanide and zinc salt, baking at 400 DEG C under vacuum for 20 h, then increasing the temperature to 600 DEG C and baking for 20 h, grinding the product after baking and washing in an acid solution, then filtering, washing with deionized water, washing with tetrahydrofuran, and drying to obtain the covalent triazine framework material;

[0019] When the organic monomer is 1,4-dicyanobenzene, preferably, after grinding and uniformly mixing 1,4-dicyanobenzene and zinc salt, baking at 400 DEG C under vacuum for 20 h, then increasing the temperature to 700 DEG C and baking for 20 h, grinding the product after baking and washing in an acid solution, then filtering, washing with deionized water, washing with tetrahydrofuran, and drying to obtain the covalent triazine framework material;

[0020] When the organic monomer is 7,7,8,8-tetracyanoquinodimethane, preferably, 7,7,8,8-tetracyanoquinodimethane is mixed with a zinc salt by grinding, then calcined at 400 ℃ for 20 h under vacuum, and then calcined at 600 ℃ for 20 h, the calcined product is ground and washed in an acid solution, then filtered, washed with deionized water, washed with tetrahydrofuran, dried, and the dried product is calcined at 880-920 ℃ for 2 h under a nitrogen atmosphere, preferably at 900 ℃ for 2 h, to obtain a covalent triazine framework material.

[0021] In some embodiments of the present application, the molybdenum source is at least one of molybdenum oxide, molybdenum chloride, ammonium molybdate, sodium molybdate, phosphomolybdic acid, sodium phosphomolybdate, ammonium thiomolybdate, preferably ammonium molybdate.

[0022] In some embodiments of the present application, the sulfur source is at least one of sulfur, hydrogen sulfide, sodium sulfide, potassium sulfide, thiourea, carbon disulfide, thioacetamide, dimethyl sulfoxide, sulfur dioxide, cysteine, methionine, mercaptan, thiophenol, and thioether, preferably thiourea.

[0023] In some embodiments of the present application, the solvent is at least one of water, methanol, ethanol, dimethyl sulfoxide, acetonitrile, and hexanediamine, preferably water.

[0024] In some embodiments of the present application, the elemental molar ratio of sulfur to molybdenum in the sulfur source and molybdenum source is 0.05-50:1, and the mass ratio of molybdenum element to nitrogen-containing porous material is 0.001-50:100.

[0025] In some embodiments of the present application, the solvothermal reaction is carried out at a temperature of 120-250 ℃ for 2-48 h.

[0026] In some embodiments of the present application, the high-temperature reduction treatment is carried out at a temperature of 150-350 ℃ for 2-6 h.

[0027] In a third aspect of the present application, the carbon dioxide hydrogenation synthesis of methanol catalyst of the first aspect is used in the catalytic synthesis of methanol from carbon dioxide and hydrogen.

[0028] In the use, the reaction temperature is 30-350 ℃, and the reaction pressure is 0.1-10 MPa.

[0029] In a fourth aspect of the present application, a method for synthesizing methanol from carbon dioxide hydrogenation is provided, which uses the carbon dioxide hydrogenation synthesis of methanol catalyst of the first aspect to catalyze the synthesis of methanol from carbon dioxide hydrogenation at a temperature of 30-350 ℃ and a pressure of 0.1-10 MPa.

[0030] The carbon dioxide hydrogenation to synthesize methanol is carried out in any one of a fixed bed reactor, a batch tank reactor, a slurry bed reactor, a fluidized bed reactor or a moving bed reactor.

[0031] The beneficial effects of the present application are:

[0032] The carbon dioxide hydrogenation to synthesize methanol catalyst provided by the present application is composed of sulfur-bridged atomic-level dispersed molybdenum anchored by a nitrogen-containing porous material, and the active metal molybdenum in the catalyst presents an atomic-level dispersed state. The catalyst has the advantages of high activity metal dispersion, synergistic effect between atomic-level dispersed molybdenum active sites and pore enrichment effect of the nitrogen-containing porous material, and the like. In terms of catalytic effect, the catalyst can realize the process of carbon dioxide hydrogenation to synthesize methanol at a wide temperature (30-350℃) and pressure (0.1-10MPa) range including room temperature. It has been verified that the catalyst catalyzes carbon dioxide hydrogenation to synthesize methanol at room temperature and low pressure, and the selectivity of methanol is as high as 99%, and the catalyst exhibits excellent stability during the reaction process, which is expected to solve the problem of catalytic conversion of carbon dioxide to methanol under mild conditions.

[0033] The catalyst preparation method provided by the present application is simple to operate, the parameters are easy to control, and industrial scale production can be easily realized BRIEF DESCRIPTION OF DRAWINGS

[0034] The drawings accompanying the specification of the present application serve to provide a further understanding of the present application, and the illustrative embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application.

[0035] Figure 1 The spherical aberration electron microscope image of the catalyst Cat1 prepared in Example 1 of the present application;

[0036] Figure 2 The reaction performance comparison chart of the catalysts Cat1, Cat13 and Cat14 in Application Examples 2, 3 and 4 catalyzing carbon dioxide hydrogenation to synthesize methanol at different temperatures;

[0037] Figure 3 The reaction stability line chart of Application Example 5 and Application Example 6 of the present application. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to more clearly understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with specific embodiments.

[0039] Example 1

[0040] A carbon dioxide hydrogenation to synthesize methanol catalyst, which uses a covalent triazine frame material prepared by taking 2,6-dicyanopyridine (2,6-DCP) as a precursor as a carrier, and the specific preparation method is as follows:

[0041] 1. Preparation of nitrogen-containing porous material

[0042] Weigh 3.0 g of 2,6-dicyanopyridine and 15.9 g of ZnCl2 solid, mix and grind in a glove box, after uniform grinding, load into an ampoule for vacuumizing and sealing, then put into a 400℃ muffle furnace for calcination for 20 hours, then increase the calcination temperature to 600℃ for further calcination for 20 hours, after cooling to room temperature, grind the calcined sample and add 1L 2mol / L hydrochloric acid solution for stirring and washing for 12 hours, then filter, deionized water washing, tetrahydrofuran washing, and vacuum drying at 150℃ for 12 hours to obtain a covalent triazine framework material 2,6-DCP-CTF.

[0043] 2. Step of loading MoS2 on 2,6-DCP-CTF,

[0044] Weigh 0.4 g of 2,6-DCP-CTF, 0.05 g of ammonium molybdate, 0.1 g of thiourea and 10 mL of water in an autoclave, then react in a 200℃ air drying oven for 20 hours, then open after cooling to room temperature, then filter, deionized water washing, tetrahydrofuran washing, and vacuum drying at 150℃ for 12 hours to obtain a MoS2-loaded nitrogen-doped carbon material sample MoS2-CTF-5.

[0045] 3. Reduce MoS2-CTF-5 in a hydrogen atmosphere at 300℃ for 2 hours to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat1.

[0046] Figure 1 The spherical aberration electron microscope image of Cat1 is shown in the figure, and the active metal molybdenum in the catalyst is in an atomic dispersion state.

[0047] Example 2

[0048] A carbon dioxide hydrogenation synthesis methanol catalyst, which uses a covalent triazine framework material prepared by taking 2,6-dicyanopyridine (2,6-DCP) as a precursor as a carrier, the difference between the specific preparation method and Example 1 is that in the step of loading MoS2 on 2,6-DCP-CTF, 0.4 g of 2,6-DCP-CTF, 0.1 g of ammonium molybdate, 0.2 g of thiourea and 20 mL of water are mixed in an autoclave, and the remaining steps are consistent with those of Example 1, to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat1.

[0049] Example 3

[0050] A carbon dioxide hydrogenation synthesis methanol catalyst, which is prepared by taking 2,6-dicyanopyridine (2,6-DCP) as a precursor of a covalent triazine framework material as a carrier, and the difference between the specific preparation method and Example 1 is that in the step of loading MoS2 on 2,6-DCP-CTF, 0.4g of 2,6-DCP-CTF, 0.2g of ammonium molybdate, 0.4g of thiourea and 40mL of water are mixed in an autoclave, and the remaining steps are consistent with those of Example 1, to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat3.

[0051] Example 4

[0052] A carbon dioxide hydrogenation synthesis methanol catalyst, which is prepared by taking 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a precursor of a covalent triazine framework material as a carrier, and the specific preparation method is as follows:

[0053] 1. Preparation of nitrogen-containing porous material

[0054] Take 3.0g of 7,7,8,8-tetracyanoquinodimethane and 10.0g of ZnCl2 solid, grind and mix in a glove box, grind uniformly, then load into an ampoule for vacuumizing and sealing, then put into a 400℃ muffle furnace for calcination for 20 hours, then increase the calcination temperature to 700℃ for further calcination for 20 hours, then grind the calcined sample and add 1L of 2mol / L hydrochloric acid solution for stirring and washing for 12 hours, then filter, deionized water washing, tetrahydrofuran washing, then vacuum drying at 150℃ for 12 hours, then place the material in a nitrogen atmosphere at 900℃ for 2 hours, to obtain a covalent triazine framework material TCNQ-CTF.

[0055] 2. Step of loading MoS2 on TCNQ-CTF

[0056] Take 0.4g of TCNQ-CTF, 0.05g of ammonium molybdate, 0.1g of thiourea and 10mL of water and mix them in an autoclave, then dry in a 200℃ air drying oven for 20 hours, then open after cooling to room temperature, then filter, deionized water washing, tetrahydrofuran washing, then vacuum drying at 150℃ for 12 hours, to obtain a MoS2-loaded nitrogen-doped carbon material sample MoS2-CTF-5.

[0057] 3. Reduce MoS2-CTF-5 in a hydrogen atmosphere at 300℃ for 2 hours to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat4.

[0058] Example 5

[0059] A carbon dioxide hydrogenation synthesis methanol catalyst, which uses a covalent triazine framework material prepared by using 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a precursor as a carrier, and the difference between the specific preparation method and Example 4 is that in the step of loading MoS2 on TCNQ-CTF, 0.4g of TCNQ-CTF, 0.1g of ammonium molybdate, 0.2g of thiourea and 20mL of water are mixed in an autoclave, and the remaining steps are consistent with Example 4, to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat5.

[0060] Example 6

[0061] A carbon dioxide hydrogenation synthesis methanol catalyst, which uses a covalent triazine framework material prepared by using 7,7,8,8-tetracyanoquinodimethane (TCNQ) as a precursor as a carrier, and the difference between the specific preparation method and Example 4 is that in the step of loading MoS2 on TCNQ-CTF, 0.4g of TCNQ-CTF, 0.1g of ammonium molybdate, 0.2g of thiourea and 20mL of water are mixed in an autoclave, and the remaining steps are consistent with Example 4, to obtain a carbon dioxide hydrogenation synthesis methanol catalyst Cat5.

[0062] Example 7

[0063] A carbon dioxide hydrogenation synthesis methanol catalyst, which uses a covalent triazine framework material prepared by using 1,4-dicyanobenzene as a precursor as a carrier, and the specific preparation method is as follows:

[0064] 1. Preparation of nitrogen-containing porous material

[0065] Take 3.0g of 1,4-dicyanobenzene and 10.0g of ZnCl2 solid, mix and grind in a glove box, then load into an ampoule for vacuumizing and sealing, then put into a 400℃ muffle furnace for calcination for 20 hours, then increase the calcination temperature to 600℃ for further calcination for 20 hours, then grind the calcined sample and add 1L of 2mol / L hydrochloric acid solution for stirring and washing for 12 hours, then filter, wash with deionized water, wash with tetrahydrofuran, and then vacuum dry at 150℃ for 12 hours to obtain a covalent triazine framework material CTF-1.

[0066] 2. Step of loading MoS2 on CTF-1

[0067] Take 0.4g of CTF-1, 0.05g of ammonium molybdate, 0.1g of thiourea and 10mL of water and mix in an autoclave, then react in a 200℃ air drying oven for 20 hours, then open after cooling to room temperature, then filter, wash with deionized water, wash with tetrahydrofuran, and then vacuum dry at 150℃ for 12 hours to obtain a MoS2-loaded nitrogen-doped carbon material sample MoS2-CTF-1.

[0068] 3. The MoS2-CTF-1 was reduced in a hydrogen atmosphere at 300 °C for 2 hours to obtain carbon dioxide hydrogenation to methanol catalyst Cat7.

[0069] Example 8

[0070] A carbon dioxide hydrogenation to methanol catalyst with a covalent triazine framework material prepared with 1,4-dicyanobenzene as a support, the difference between the specific preparation method and Example 7 is that in the step of loading MoS2 on CTF-1, 0.4 g of CTF-1, 0.1 g of ammonium molybdate, 0.2 g of thiourea and 20 mL of water are mixed in an autoclave, and the remaining steps are consistent with Example 7, to obtain carbon dioxide hydrogenation to methanol catalyst Cat8.

[0071] Example 9

[0072] A carbon dioxide hydrogenation to methanol catalyst with a covalent triazine framework material prepared with 1,4-dicyanobenzene as a support, the difference between the specific preparation method and Example 7 is that in the step of loading MoS2 on CTF-1, 0.4 g of CTF-1, 0.2 g of ammonium molybdate, 0.4 g of thiourea and 40 mL of water are mixed in an autoclave, and the remaining steps are consistent with Example 7, to obtain carbon dioxide hydrogenation to methanol catalyst Cat9.

[0073] Example 10

[0074] A carbon dioxide hydrogenation to methanol catalyst with a commercial nitrogen-containing porous activated carbon (specific surface area ~ 1000 m 2 / g, nitrogen content ~ 5 wt.%) as a support, the specific preparation method is as follows:

[0075] 1. 0.4 g of commercial nitrogen-containing porous activated carbon, 0.05 g of ammonium molybdate, 0.1 g of thiourea and 10 mL of water are mixed in an autoclave, then dried in a blast drying oven at 200 °C for 20 hours, and then filtered, washed with deionized water, washed with tetrahydrofuran, and vacuum dried at 150 °C for 12 hours to obtain a MoS2-loaded nitrogen-doped carbon material sample.

[0076] 2. The MoS2-loaded nitrogen-doped carbon material sample is reduced in a hydrogen atmosphere at 300 °C for 2 hours to obtain carbon dioxide hydrogenation to methanol catalyst Cat10.

[0077] Example 11

[0078] A carbon dioxide hydrogenation to methanol catalyst with a commercial nitrogen-containing porous activated carbon (specific surface area ~ 1000 m 2Using a carrier (with a nitrogen content of ~5wt.%), the specific preparation method differs from that of Example 10 in that 0.4g of commercial nitrogen-containing porous activated carbon, 0.1g of ammonium molybdate, 0.2g of thiourea and 20mL of water are weighed and mixed in a hydrothermal reactor, while the remaining steps are the same as in Example 10, to obtain the carbon dioxide hydrogenation to methanol synthesis catalyst Cat11.

[0079] Example 12

[0080] A catalyst for the hydrogenation of carbon dioxide to methanol, which uses commercially available nitrogen-containing porous activated carbon (specific surface area ~1000 m²) 2 Using a carrier (with a nitrogen content of ~5wt.%), the specific preparation method differs from that of Example 10 in that 0.4g of commercial nitrogen-containing porous activated carbon, 0.2g of ammonium molybdate, 0.4g of thiourea and 40mL of water are weighed and mixed in a hydrothermal reactor, while the remaining steps are the same as in Example 10, to obtain the carbon dioxide hydrogenation to methanol synthesis catalyst Cat12.

[0081] Comparative Example 1

[0082] A catalyst for the hydrogenation of carbon dioxide to methanol, which is a layered MoS2 catalyst without a support, is prepared by the following method:

[0083] 1. Weigh 0.2g ammonium molybdate, 0.4g thiourea and 20mL water and mix them in a hydrothermal reactor. Then react in a 200℃ forced-air drying oven for 20 hours. After cooling to room temperature, open the oven, filter, wash with deionized water and tetrahydrofuran, and then dry under vacuum at 150℃ for 12 hours to obtain a layered MoS2 catalyst.

[0084] 2. The layered MoS2 catalyst was reduced in a hydrogen atmosphere at 300°C for 2 hours to obtain the carbon dioxide hydrogenation to methanol catalyst Cat13.

[0085] Comparative Example 2

[0086] A catalyst for the hydrogenation of carbon dioxide to methanol, using commercial alumina as a support, is prepared as follows:

[0087] 1. Steps for supporting MoS2 on alumina

[0088] Weigh 0.4g of alumina, 0.05g of ammonium molybdate, 0.1g of thiourea and 10mL of water and mix them in a hydrothermal reactor. Then react in a drying oven at 200℃ for 20 hours. After cooling to room temperature, open the oven, filter, wash with deionized water and tetrahydrofuran, and then vacuum dry at 150℃ for 12 hours to obtain MoS2-supported alumina material.

[0089] 2. The alumina material supported on MoS2 was reduced in a hydrogen atmosphere at 300°C for 2 hours to obtain the catalyst Cat14 for the hydrogenation of carbon dioxide to methanol.

[0090] Application Example 1

[0091] 0.1 g of Cat 1 catalyst with particle size of 30-60 mesh was charged into a fixed bed reactor, and pure hydrogen gas stream was introduced at a pressure of 1 bar and a flow rate of 20 mL / min. The catalyst was pretreated by heating to 300°C for 2 h, and then the temperature was lowered to 30°C. The mixed gas atmosphere of carbon dioxide and hydrogen was switched to, with a volume ratio of hydrogen to carbon dioxide of 3:1, and the pressure was increased to 9 bar. The carbon dioxide hydrogenation reaction was carried out at 30°C with a gas flow rate of 30 mL / min. The reaction products were analyzed online by a gas chromatograph, and qualitative and quantitative analyses were performed by TCD and FID detectors, respectively. The specific reaction performance is listed in Table 1.

[0092] Cat 1 catalyst was replaced by Cat 2-Cat 12 catalysts, and it was determined that Cat 2-Cat 12 catalysts exhibited similar catalytic performance to Cat 1 catalyst.

[0093] Application Example 2

[0094] 0.1 g of Cat 1 catalyst with particle size of 30-60 mesh was charged into a fixed bed reactor, and pure hydrogen gas stream was introduced at a pressure of 1 bar and a flow rate of 20 mL / min. The catalyst was pretreated by heating to 300°C for 2 h, and then the temperature was lowered to 30°C. The mixed gas atmosphere of carbon dioxide and hydrogen was switched to, with a volume ratio of hydrogen to carbon dioxide of 3:1, and the pressure was increased to 15 bar. The carbon dioxide hydrogenation reaction was carried out at 30°C, 60°C, 120°C, 180°C, 220°C, and 260°C, respectively, with a gas flow rate of 30 mL / min, and each temperature was reacted for 5 h. The reaction products were analyzed online by a gas chromatograph, and qualitative and quantitative analyses were performed by TCD and FID detectors, respectively. The specific reaction performance is listed in Table 1.

[0095] Cat 1 catalyst was replaced by Cat 2-Cat 12 catalysts, and it was determined that Cat 2-Cat 12 catalysts exhibited similar catalytic performance to Cat 1 catalyst.

[0096] Table 1. Evaluation results of Cat 1 catalyst performance

[0097]

[0098] Application Example 3:

[0099] Take 0.1 g (the mass of the active component) of Cat 13 catalyst with particle size of 30-60 mesh and load into a fixed bed reactor, pass pure hydrogen gas stream, under the conditions of pressure of 1 bar, flow rate of 20 mL / min, warm up to 300°C to pretreat the catalyst, time of 2 h, then reduce the temperature to 30°C. Switch to a mixed atmosphere of carbon dioxide and hydrogen, where the volume ratio of hydrogen to carbon dioxide is 3:1, pressurize to 15 bar, gas flow rate is 30 mL / min, respectively, at 30°C, 60°C, 120°C, 180°C, 220°C, 260°C, carry out carbon dioxide hydrogenation to methanol reaction, each temperature reaction for 5 h. The reaction product is analyzed online using a gas chromatograph, and qualitative and quantitative analysis is carried out using TCD and FID detectors, respectively.

[0100] Application Example 4

[0101] Take 0.1 g (the mass of the active component) of Cat 13 catalyst with particle size of 30-60 mesh and load into a fixed bed reactor, pass pure hydrogen gas stream, under the conditions of pressure of 1 bar, flow rate of 20 mL / min, warm up to 300°C to pretreat the catalyst, time of 2 h, then reduce the temperature to 30°C. Switch to a mixed atmosphere of carbon dioxide and hydrogen, where the volume ratio of hydrogen to carbon dioxide is 3:1, pressurize to 15 bar, gas flow rate is 30 mL / min, respectively, at 30°C, 60°C, 120°C, 180°C, 220°C, 260°C, carry out carbon dioxide hydrogenation to methanol reaction, each temperature reaction for 5 h. The reaction product is analyzed online using a gas chromatograph, and qualitative and quantitative analysis is carried out using TCD and FID detectors, respectively.

[0102] Figure 2 The reaction performance comparison chart of carbon dioxide hydrogenation to methanol reaction catalyzed by Cat 1, Cat 13 and Cat 14 in Application Examples 2, 3 and 4, from the chart, it can be seen that the catalytic performance of Cat 1 is much greater than that of Cat 13 and Cat 14 at any temperature.

[0103] Application Example 5

[0104] Take 0.1 g (mass of active component) of Cat1 catalyst with particle size of 30-60 mesh into a fixed bed reactor, and pre-treat the catalyst by passing pure hydrogen gas stream at a pressure of 1 bar and a flow rate of 20 mL / min, and heating to 300℃ for 2 h, and then reduce the temperature to 30℃. Switch to a mixed atmosphere of carbon dioxide and hydrogen with a volume ratio of hydrogen to carbon dioxide of 3:1, and pressurize to 15 bar, and test the stability of the carbon dioxide hydrogenation to methanol reaction at 30℃ at a gas flow rate of 30 mL / min, and analyze the reaction products on-line by gas chromatography, and qualitatively and quantitatively analyze by TCD and FID detectors, respectively.

[0105] Application Example 6

[0106] Take 0.1 g (mass of active component) of Cat1 catalyst with particle size of 30-60 mesh into a fixed bed reactor, and pre-treat the catalyst by passing pure hydrogen gas stream at a pressure of 1 bar and a flow rate of 20 mL / min, and heating to 300℃ for 2 h, and then reduce the temperature to 30℃. Switch to a mixed atmosphere of carbon dioxide and hydrogen with a volume ratio of hydrogen to carbon dioxide of 3:1, and pressurize to 15 bar, and test the stability of the carbon dioxide hydrogenation to methanol reaction at 180℃ at a gas flow rate of 30 mL / min, and analyze the reaction products on-line by gas chromatography, and qualitatively and quantitatively analyze by TCD and FID detectors, respectively.

[0107] Figure 3 For the reaction stability test of the Cat1 catalyzed carbon dioxide hydrogenation to methanol reaction at different temperatures in Application Example 5 and Application Example 6, it can be seen from the figure that, whether at high temperature (180℃) or at low temperature (30℃), the Cat1 catalyst still maintains high catalytic activity after 120 h of reaction.

[0108] The above only describes preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A catalyst for the synthesis of methanol by the hydrogenation of carbon dioxide comprising a support and a catalytic component supported on said support, characterized in that, The carbon dioxide hydrogenation synthesis methanol catalyst is composed of sulfur-bridged atomic-level dispersed molybdenum anchored by a nitrogen-containing porous material, the carrier is a nitrogen-containing porous material, the catalytic component is sulfur and molybdenum, the molybdenum is dispersed on the surface of the nitrogen-containing porous material carrier in an atomic level, the molybdenum accounts for 0.001 wt.%-50 wt.% of the total mass of the catalyst, and the sulfur accounts for 0.001 wt.%-50 wt.% of the total mass of the catalyst; The nitrogen-containing porous material is a covalent triazine framework material or a nitrogen-doped porous carbon material; The preparation method of the carbon dioxide hydrogenation synthesis methanol catalyst comprises the following steps: mixing a molybdenum source, a sulfur source, a nitrogen-containing porous material and a solvent, carrying out a solvothermal reaction, filtering, washing and drying the obtained mixed solution after the reaction is completed, and obtaining a catalyst precursor material; The catalyst precursor material is subjected to high-temperature reduction treatment in a reducing atmosphere to obtain the carbon dioxide hydrogenation synthesis methanol catalyst; The solvothermal reaction is carried out at a reaction temperature of 120-250 DEG C for 2-48 h; The high-temperature reduction treatment is carried out at a reduction temperature of 150-350 DEG C for 2-6 h.

2. The catalyst for carbon dioxide hydrocarbon synthesis of methanol according to claim 1, wherein, The nitrogen-containing porous material has a specific surface area of 100-5000 m 2 / g and a nitrogen content of 0.01-60 wt.%.

3. A process for preparing a catalyst for the synthesis of methanol by the hydrogenation of carbon dioxide as claimed in claim 1 or 2, characterized in that, The preparation method comprises the following steps: Mixing a molybdenum source, a sulfur source, a nitrogen-containing porous material and a solvent, carrying out a solvothermal reaction, filtering, washing and drying the obtained mixed solution after the reaction is completed, and obtaining a catalyst precursor material; The catalyst precursor material is subjected to high-temperature reduction treatment in a reducing atmosphere to obtain the carbon dioxide hydrogenation synthesis methanol catalyst; The solvothermal reaction is carried out at a reaction temperature of 120-250 DEG C for 2-48 h; The high-temperature reduction treatment is carried out at a reduction temperature of 150-350 DEG C for 2-6 h.

4. The method for preparing the catalyst for the hydrogenation of carbon dioxide to methanol as described in claim 3, characterized in that, The nitrogen-containing porous material is a covalent triazine framework material or a nitrogen-doped porous carbon material, and the preparation method of the covalent triazine framework material comprises the following steps: The organic monomer and the zinc salt are uniformly ground and mixed, then calcined at 380-420 DEG C for 18-22 h under vacuum, and then heated to 600-700 DEG C for calcination for 18-22 h, the calcined product is ground and washed in an acid solution, and then filtered, washed with deionized water, washed with tetrahydrofuran, and dried to obtain the covalent triazine framework material.

5. The method for preparing the catalyst for the hydrogenation of carbon dioxide to methanol as described in claim 4, characterized in that, The organic monomer is selected from one of 2,6-pyridine dicyanide, 7,7,8,8-tetracyanoquinodimethane or 1,4-dicyanobenzene; the zinc salt is zinc chloride; and the molar ratio of the organic monomer to the zinc salt is 1:1-1:

10.

6. The method for preparing the catalyst for the hydrogenation of carbon dioxide to methanol as described in claim 4, characterized in that, The organic monomer is 7,7,8,8-tetracyanoquinodimethane, and the obtained product is calcined at 880-920 DEG C for 2 h under a nitrogen atmosphere to obtain the covalent triazine framework material.

7. The method of claim 3, wherein the catalyst is prepared by the steps of: (a) preparing a solution of the catalyst precursor; (b) adding the solution of the catalyst precursor to the support; (c) drying the support; (d) calcining the support; (e) reducing the support; and (f) washing the support. The molybdenum source is at least one of molybdenum oxide, molybdenum chloride, ammonium molybdate, sodium molybdate, phosphomolybdic acid, sodium phosphomolybdate, and ammonium thiomolybdate; The sulfur source is at least one of sulfur, hydrogen sulfide, sodium sulfide, potassium sulfide, thiourea, carbon disulfide, thioacetamide, dimethyl sulfoxide, sulfur dioxide, cysteine, methionine, mercaptan, thiophenol, and sulfide; The solvent is at least one of water, methanol, ethanol, dimethyl sulfoxide, acetonitrile, and hexanediamine; The element molar ratio of sulfur to molybdenum in the feeding of the sulfur source and the molybdenum source is 0.05-50:1; the mass ratio of molybdenum element to the nitrogen-containing porous material is 0.001-50:

100.

8. Use of the carbon dioxide hydrogenation methanol synthesis catalyst of claim 1 or 2 in catalyzing carbon dioxide hydrogenation synthesis of methanol. In the use, the reaction temperature is 30-350 DEG C, and the reaction pressure is 0.1-10 MPa.

9. A process for the synthesis of methanol from carbon dioxide by hydrogenation, characterized in that, The carbon dioxide hydrogenation methanol synthesis catalyst of claim 1 or 2 is used to catalyze carbon dioxide hydrogenation synthesis of methanol at 30-350 DEG C and 0.1-10 MPa. The carbon dioxide hydrogenation methanol synthesis is carried out in any one of a fixed bed reactor, a batch tank reactor, a slurry bed reactor, a fluidized bed reactor or a moving bed reactor.

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