Indium-based catalyst as well as preparation method and application thereof

Abstract

The invention discloses an indium-based catalyst as well as a preparation method and application thereof, and relates to the technical field of catalysts. The indium-based catalyst comprises a molecular sieve carrier and an active metal component limited in a molecular sieve; wherein the molecular sieve carrier is an all-silicon MFI type molecular sieve carrier; wherein the active metal component comprises a main active metal component and a noble metal auxiliary agent; the main active metal component comprises In, and the precious metal auxiliary agent comprises any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir. The catalyst disclosed by the invention has relatively high carbon dioxide hydrogenation activity, the catalyst is not inactivated within 100 hours of reaction, and the reaction performance is maintained at a relatively high level. The prepared indium-based metal confinement catalyst has excellent performance in the reaction of preparing methanol through carbon dioxide hydrogenation, and has a good application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to an indium-based catalyst and a preparation method and application thereof, and in particular to an indium-based catalyst for preparing methanol by hydrogenating carbon dioxide and a preparation method and application thereof. Background Art

[0002] Carbon dioxide is a typical greenhouse gas that is emitted into the atmosphere through the burning of fossil fuels and various human industrial activities. As of now, the concentration of carbon dioxide has reached 419ppm. The rising level of carbon dioxide in the atmosphere has led to global warming, which seriously threatens the human living environment. Therefore, it is urgent to develop and establish a reliable CO 2 Control method.

[0003] Converting carbon dioxide into economically relevant products, such as methanol, is an eco-friendly and green way to alleviate the shortage of fossil fuels and provide cheap chemical raw materials. In the process of balanced conversion of carbon dioxide into methanol at high temperature, the development of effective catalysts for high concentrations of CO 2 Catalyst design to improve methanol selectivity and yield under CO2-rich conditions is a challenge in the development of this process. 2 In the hydrogenation reaction, the reverse water-gas shift reaction (side reaction) competes with the reaction to produce methanol.

[0004] In industry, Cu-ZnO-Al is generally used. 2 O 3 As a catalyst, although the catalyst has good carbon dioxide conversion activity, the reverse water gas shift reaction is relatively serious, and the catalyst is easily deactivated in high temperature, high pressure and water vapor conditions. Therefore, it is urgent to find a CO2 catalyst with higher selectivity and more stable performance. 2 Hydrogenation methanol catalyst to replace Cu-ZnO-Al 2 O 3 .

[0005] Recently, studies have found that In containing rich oxygen vacancies 2 O 3 Oxide catalysts can significantly inhibit the highly selective production of methanol in the RWGS reaction. Especially when used in combination with other hydrogenation metals, such as rhodium, gold, palladium, platinum, nickel, and cobalt, indium-based catalysts exhibit good carbon dioxide hydrogenation activity and methanol selectivity, and have good application prospects. 2 O 3 The activity of indium-based catalysts is weaker than that of Cu-based catalysts, and the yield of methanol from currently known indium-based catalysts is still low. In addition, the relatively high metal dosage (price) and the uncertainty of the stability of the indium system have limited the use of indium-based catalysts.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide an indium-based catalyst and its preparation method and application. The indium-based catalyst of the present invention confines indium metal with high methanol selectivity and noble metal with high hydrogenation activity in zeolite crystals, while reducing the amount of metal used, so that the catalyst can obtain extremely high methanol yield and stability in the reaction of hydrogenating carbon dioxide to methanol.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides an indium-based catalyst, the indium-based catalyst comprising a molecular sieve carrier and an active metal component confined in the molecular sieve;

[0010] Wherein, the molecular sieve carrier is an all-silicon MFI type molecular sieve carrier;

[0011] Among them, the active metal component includes a main active metal component and a precious metal additive; the main active metal component includes In, and the precious metal additive includes any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir.

[0012] Preferably, the indium-based catalyst is composed of the following components in terms of mass percentage: 0.5-5% of a main active metal component, 0.1-2% of a noble metal additive, and the remainder being a molecular sieve carrier.

[0013] Preferably, the all-silicon MFI type molecular sieve carrier is an S-1 type all-silicon molecular sieve.

[0014] In a second aspect, the present invention provides a method for preparing the indium-based catalyst as described in the first aspect, the preparation method comprising:

[0015] The indium metal compound and the noble metal compound are respectively prepared into solutions to obtain an indium metal solution and a noble metal solution;

[0016] Mixing ethyl orthosilicate, tetrapropylammonium hydroxide and water to obtain a mixed solution;

[0017] Adding indium metal solution and noble metal solution dropwise to the mixed solution, stirring and performing a hydrothermal reaction;

[0018] The product obtained by the hydrothermal reaction is washed, filtered, dried and calcined in sequence to obtain an indium-based catalyst.

[0019] Preferably, the indium metal compound includes any one of indium salt, indium oxide, indium hydroxide or indium complex, or a combination of at least two thereof, preferably an indium salt.

[0020] Preferably, the indium salt comprises indium nitrate and / or indium halide, and more preferably indium nitrate;

[0021] Preferably, the precious metal compound comprises any one or a combination of at least two of precious metal salts, precious metal oxides, precious metal hydroxides or precious metal complexes, preferably precious metal salts; wherein the precious metal additive comprises any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir.

[0022] Preferably, the noble metal salt includes any one of noble metal nitrates, noble metal halides or noble metal sulfates, or a combination of at least two of them.

[0023] Preferably, the noble metal is Rh and / or Pd.

[0024] Preferably, the solvent of the indium metal solution is water.

[0025] Preferably, the concentration of the indium metal compound in the indium metal solution is 0.1-1 g / mL.

[0026] Preferably, the solvent of the noble metal solution is an aqueous solution of ethylenediamine.

[0027] Preferably, the concentration of ethylenediamine in the ethylenediamine aqueous solution is 0.1-0.5 g / mL.

[0028] Preferably, the concentration of the noble metal compound in the noble metal solution is 0.01 to 0.05 g / mL.

[0029] Preferably, the mass ratio of tetraethyl orthosilicate, tetrapropylammonium hydroxide and water is (3-4):(0.8-1.2):(10-25).

[0030] Preferably, the temperature for dropwise adding the indium metal solution and the noble metal solution is 10-35°C.

[0031] Preferably, the stirring time is 5 to 15 hours.

[0032] Preferably, the temperature of the hydrothermal reaction is 140-180° C., and the time of the hydrothermal reaction is 24-96 hours.

[0033] Preferably, the specific steps of the hydrothermal reaction are:

[0034] (a) tetrapropylammonium hydroxide and water are mixed, and a noble metal solution is added dropwise to obtain a mixed solution 1;

[0035] (b) adding tetraethyl orthosilicate to the mixed solution 1 to obtain a mixed solution 2;

[0036] (c) adding indium metal solution dropwise to the second mixed solution to carry out a hydrothermal reaction to obtain a product.

[0037] Preferably, in step (b), stirring is continued for 5 to 15 hours after adding ethyl orthosilicate.

[0038] Preferably, in step (c), the indium metal solution is stirred for 0.1 to 1 h after being added.

[0039] Preferably, in step (c), the heating rate of the hydrothermal reaction is 1 to 10° C. / min, the temperature of the hydrothermal reaction is 140 to 180° C., and the time of the hydrothermal reaction is 24 to 96 h.

[0040] Preferably, the drying temperature is 70-90° C., and the drying time is 6-12 hours.

[0041] Preferably, the calcination temperature is 450-650° C., and the calcination time is 2-10 hours.

[0042] Preferably, the calcination further includes a molding step, wherein the molding is: tableting molding, followed by granulation molding or extrusion molding.

[0043] In a third aspect, the present invention provides a use of the indium-based catalyst as described in the first aspect, or the indium-based catalyst prepared by the preparation method as described in the second aspect, in catalyzing the hydrogenation of carbon dioxide to produce methanol.

[0044] In a fourth aspect, the present invention provides a method for preparing methanol by hydrogenating carbon dioxide, the method comprising the following steps:

[0045] In the presence of an indium-based catalyst, carbon dioxide and hydrogen are reacted to prepare methanol;

[0046] Wherein, the indium-based catalyst includes the indium-based catalyst described in the first aspect, or the indium-based catalyst prepared by the preparation method described in the second aspect.

[0047] Preferably, the reaction is carried out in any one of a fixed bed reactor, a moving bed reactor or a fluidized bed reactor.

[0048] Preferably, the molar ratio of hydrogen to carbon dioxide is (1-30):1.

[0049] Preferably, the reaction temperature is 200-350° C., and the reaction pressure is 2-10 MPa.

[0050] Preferably, the space velocity of the reaction is 6000 to 12000 mL / h / g.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] (1) The indium-based catalyst of the present invention uses an all-silicon MFI molecular sieve carrier to confine the metal component, which can effectively prevent the catalyst from sintering, and the performance has no significant change after 100 hours of testing;

[0053] (2) The active metal component in the indium-based catalyst of the present invention is a uniformly dispersed metal nanostructure, which can improve the catalyst activity, reduce the amount of metal used, and save metal resources;

[0054] (3) The indium-based catalyst of the present invention uses a bimetallic catalyst, which greatly improves the selectivity of methanol while ensuring high activity, so that the overall yield of methanol is significantly increased;

[0055] (4) The indium-based catalyst of the present invention is preferably used in a gas with a molar ratio of H 2 :CO 2 is 6, the temperature is 290℃, the pressure is 5Mpa, and the space velocity is 6000mL g cat -1 h -1 Under these conditions, the carbon dioxide conversion rate can reach 27%, the methanol yield can reach 24% (close to the equilibrium yield), and the selectivity of the main by-product CO is less than 12%, which has good industrial application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0057] Figure 1 This is a graph showing the stability test results of 3% In-0.5% Rh@S-1 catalyst. DETAILED DESCRIPTION

[0058] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0059] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0061] In a first aspect, the present invention provides an indium-based catalyst, the indium-based catalyst comprising a molecular sieve carrier and an active metal component confined in the molecular sieve;

[0062] Wherein, the molecular sieve carrier is an all-silicon MFI type molecular sieve carrier;

[0063] Among them, the active metal component includes a main active metal component and a precious metal additive; the main active metal component includes In, and the precious metal additive includes any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir.

[0064] In the present invention, the indium-based catalyst uses an all-silicon MFI-type molecular sieve carrier to confine the metal component, which can effectively prevent the catalyst sintering problem; and the active metal component in the indium-based catalyst of the present invention is a uniformly dispersed metal nanostructure, which can improve the catalyst activity, reduce the amount of metal used, and save metal resources; in addition, the indium-based catalyst of the present invention uses a bimetallic catalyst, which greatly improves the selectivity of methanol while ensuring high activity, thereby significantly increasing the overall yield of methanol.

[0065] As an optional implementation, the indium-based catalyst is composed of the following components in terms of mass percentage: 0.5-5% of a main active metal component, 0.1-2% of a noble metal additive, and the remainder being a molecular sieve carrier.

[0066] Taking the total mass of the indium-based catalyst as 100%, the content of the main active metal component is 0.5-5%, for example, it can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc.

[0067] Taking the total mass of the indium-based catalyst as 100%, the content of the precious metal additive is 0.1-2%, for example, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, etc.

[0068] As an optional embodiment, the all-silicon MFI type molecular sieve carrier is an S-1 type all-silicon molecular sieve.

[0069] In a second aspect, the present invention provides a method for preparing the indium-based catalyst as described in the first aspect, the preparation method comprising:

[0070] The indium metal compound and the noble metal compound are respectively prepared into solutions to obtain an indium metal solution and a noble metal solution;

[0071] Mixing ethyl orthosilicate, tetrapropylammonium hydroxide and water to obtain a mixed solution;

[0072] Adding indium metal solution and noble metal solution dropwise to the mixed solution, stirring and performing a hydrothermal reaction;

[0073] The product obtained by the hydrothermal reaction is washed, filtered, dried and calcined in sequence to obtain an indium-based catalyst.

[0074] As an optional embodiment, the indium metal compound includes any one of an indium salt, an indium oxide, an indium hydroxide or an indium complex, or a combination of at least two of them.

[0075] As an optional embodiment, the indium metal compound is preferably an indium salt.

[0076] As an optional embodiment, the indium salt includes indium nitrate and / or indium halide, and is more preferably indium nitrate.

[0077] As an optional embodiment, the precious metal compound includes any one of precious metal salts, precious metal oxides, precious metal hydroxides or precious metal complexes, or a combination of at least two of them; wherein the precious metal additive includes any one of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir, or a combination of at least two of them.

[0078] As an optional embodiment, the precious metal compound is preferably a precious metal salt; wherein the precious metal additive includes any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir.

[0079] As an optional embodiment, the noble metal salt includes any one of noble metal nitrates, noble metal halides or noble metal sulfates, or a combination of at least two of them.

[0080] As an optional embodiment, the noble metal is preferably Rh and / or Pd.

[0081] As an optional implementation, the solvent of the indium metal solution is water.

[0082] As an optional embodiment, the concentration of the indium metal compound in the indium metal solution is 0.1-1 g / mL, for example, it can be 0.1 g / mL, 0.2 g / mL, 0.3 g / mL, 0.4 g / mL, 0.5 g / mL, 0.6 g / mL, 0.7 g / mL, 0.8 g / mL, 0.9 g / mL, 1 g / mL, etc.

[0083] As an optional embodiment, the solvent of the noble metal solution is an aqueous solution of ethylenediamine.

[0084] As an optional embodiment, the concentration of ethylenediamine in the ethylenediamine aqueous solution is 0.1-0.5 g / mL, for example, it can be 0.1 g / mL, 0.15 g / mL, 0.2 g / mL, 0.25 g / mL, 0.3 g / mL, 0.35 g / mL, 0.4 g / mL, 0.45 g / mL, 0.5 g / mL, etc.

[0085] As an optional embodiment, the concentration of the noble metal compound in the noble metal solution is 0.01 to 0.05 g / mL, for example, 0.01 g / mL, 0.02 g / mL, 0.03 g / mL, 0.04 g / mL, 0.05 g / mL, etc.

[0086] As an optional embodiment, the mass ratio of tetraethyl orthosilicate, tetrapropylammonium hydroxide and water is (3-4):(0.8-1.2):(10-25);

[0087] Among them, "3-4" can be, for example, 3, 3.2, 3.4, 3.6, 3.8, 4, etc.;

[0088] Here, “0.8-1.2” can be, for example, 0.8, 0.9, 1.0, 1.1, 1.2, etc.;

[0089] Here, “10-25” can be, for example, 10, 12, 14, 16, 18, 20, 22, 24, 25, etc.

[0090] As an optional embodiment, the temperature for dripping the indium metal solution and the precious metal solution is 10-35°C, for example, it can be 10°C, 12°C, 14°C, 16°C, 18°C, 20°C, 22°C, 24°C, 25°C, 26°C, 28°C, 30°C, 32°C, 34°C, 35°C, etc.

[0091] As an optional embodiment, the stirring time is 5 to 15 hours, for example, it can be 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, etc.

[0092] As an optional embodiment, the temperature of the hydrothermal reaction is 140-180°C, for example, it can be 140°C, 142°C, 145°C, 148°C, 150°C, 152°C, 155°C, 158°C, 160°C, 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, 180°C, etc.

[0093] As an optional embodiment, the time of the hydrothermal reaction is 24 to 96 h, for example, it can be 24h, 26h, 28h, 30h, 32h, 34h, 36h, 38h, 40h, 42h, 44h, 46h, 48h, 50h, 52h, 54h, 56h, 58h, 60h, 62h, 64h, 66h, 68h, 70h, 72h, 74h, 76h, 78h, 80h, 82h, 84h, 86h, 88h, 90h, 92h, 94h, 96h and the like.

[0094] As an optional embodiment, the specific steps of the hydrothermal reaction are:

[0095] (a) tetrapropylammonium hydroxide and water are mixed, and a noble metal solution is added dropwise to obtain a mixed solution 1;

[0096] (b) adding tetraethyl orthosilicate to the mixed solution 1 to obtain a mixed solution 2;

[0097] (c) adding indium metal solution dropwise to the second mixed solution to carry out a hydrothermal reaction to obtain a product.

[0098] As an optional embodiment, in step (b), after adding tetraethyl orthosilicate, stirring is required for 5 to 15 hours, for example, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, etc.

[0099] As an optional implementation, in step (c), after adding the indium metal solution, stirring is required for 0.1 to 1 h, for example, 0.1 h, 0.2 h, 0.4 h, 0.5 h, 0.6 h, 0.8 h, 1 h, etc.

[0100] As an optional embodiment, in step (c), the heating rate of the hydrothermal reaction is 1 to 10°C / min, for example, it can be 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, etc.

[0101] As an optional embodiment, in step (c), the temperature of the hydrothermal reaction is 140-180°C, for example, it can be 140°C, 142°C, 144°C, 146°C, 148°C, 150°C, 152°C, 155°C, 158°C, 160°C, 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, 180°C, etc.

[0102] As an optional embodiment, in step (c), the time of the hydrothermal reaction is 24 to 96 h, for example, it can be 24 h, 26 h, 28 h, 30 h, 32 h, 34 h, 36 h, 38 h, 40 h, 42 h, 44 h, 46 h, 48 h, 50 h, 52 h, 54 h, 56 h, 58 h, 60 h, 62 h, 64 h, 66 h, 68 h, 70 h, 72 h, 74 h, 76 h, 78 h, 80 h, 82 h, 84 h, 86 h, 88 h, 90 h, 92 h, 94 h, 96 h, etc.

[0103] As an optional embodiment, the drying temperature is 70-90°C, for example, it can be 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, etc.

[0104] As an optional implementation manner, the drying time is 6 to 12 hours, for example, it can be 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, etc.

[0105] As an optional embodiment, the calcination temperature is 450-650°C, for example, it can be 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, 560°C, 580°C, 600°C, 620°C, 640°C, 650°C, etc.

[0106] As an optional embodiment, the calcination time is 2 to 10 hours, for example, it can be 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, etc.

[0107] As an optional embodiment, the calcination further includes a molding step, and the molding is: tableting molding, and then granulation molding or extrusion molding.

[0108] In a third aspect, the present invention provides a use of the indium-based catalyst as described in the first aspect, or the indium-based catalyst prepared by the preparation method as described in the second aspect, in catalyzing the hydrogenation of carbon dioxide to produce methanol.

[0109] In a fourth aspect, the present invention provides a method for preparing methanol by hydrogenating carbon dioxide, the method comprising the following steps:

[0110] In the presence of an indium-based catalyst, carbon dioxide and hydrogen are reacted to prepare methanol;

[0111] Wherein, the indium-based catalyst includes the indium-based catalyst described in the first aspect, or the indium-based catalyst prepared by the preparation method described in the second aspect.

[0112] As an optional embodiment, the reaction is carried out in any one of a fixed bed reactor, a moving bed reactor or a fluidized bed reactor.

[0113] As an optional embodiment, the molar ratio of hydrogen to carbon dioxide is (1-30):1, for example, it can be 1:1, 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, 22:1, 24:1, 26:1, 28:1, 30:1, etc.

[0114] As an optional embodiment, the reaction temperature is 200-350°C, for example, it can be 200°C, 220°C, 240°C, 260°C, 280°C, 300°C, 320°C, 340°C, 350°C, etc.

[0115] As an optional embodiment, the reaction pressure is 2 to 10 MPa, for example, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, etc.

[0116] As an optional embodiment, the space velocity of the reaction is 6000-12000 mL / h / g, for example, it can be 6000 mL / h / g, 7000 mL / h / g, 8000 mL / h / g, 9000 mL / h / g, 10000 mL / h / g, 11000 mL / h / g, 12000 mL / h / g, etc.

[0117] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0118] Example 1

[0119] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, and the indium-based catalyst 3% In-0.5% Rh@S-1 is prepared by the following steps:

[0120] S1. Dissolve 1 g of indium nitrate in 10 mL of water to obtain an indium metal solution; dissolve 1 g of hydrated rhodium chloride in 25 mL of a 0.35 g / mL aqueous solution of ethylenediamine to obtain a metallic rhodium solution;

[0121] S2, weigh 7.78g ultrapure water and 2.22g tetrapropylammonium hydroxide (TPAOH, 25wt.%), add them to 100mL hydrothermal kettle in turn, stir for 3min; add 0.3mL of the prepared metal rhodium solution, stir for 1min; then add 3.47g of tetraethyl orthosilicate (TEOS), stir for 7.5h; add 0.8mL of indium metal solution, continue stirring for 30min; heat to 170℃ at a rate of 5℃ / min, and hydrothermally react for 72h;

[0122] S3. Wash and filter the material obtained from the hydrothermal reaction, collect the solid product, dry it at 80° C. for 9 hours, and then calcine it at 550° C. for 6 hours to obtain the indium-based catalyst 3% In-0.5% Rh@S-1.

[0123] Example 2

[0124] This embodiment provides an indium-based catalyst 3% In-0.5% Pd@S-1, and the indium-based catalyst 3% In-0.5% Pd@S-1 is prepared by the following steps:

[0125] S1. Dissolve 1 g of indium nitrate in 10 mL of water to obtain an indium metal solution; dissolve 1 g of palladium chloride in a hydrochloric acid solution, add 8 mL of ethylenediamine, stir to dissolve, and dilute to 25 mL to obtain a metal palladium solution;

[0126] S2, weigh 7.78g ultrapure water and 2.22g tetrapropylammonium hydroxide (TPAOH, 25wt.%), add them to 100mL hydrothermal kettle in turn, stir for 3min; add 0.2mL of prepared metal palladium solution, stir for 1min; then add 3.47g of tetraethyl orthosilicate (TEOS), stir for 7.5h; add 0.8mL of indium metal solution, continue stirring for 30min; heat to 170℃ at a rate of 5℃ / min, and hydrothermally react for 72h;

[0127] S3. Wash and filter the material obtained from the hydrothermal reaction, collect the solid product, dry it at 80° C. for 9 hours, and then calcine it at 550° C. for 6 hours to obtain the indium-based catalyst 3% In-0.5% Pd@S-1.

[0128] Example 3

[0129] This embodiment provides an indium-based catalyst 3% In-0.5% Pt@S-1, which differs from Embodiment 1 in that rhodium chloride is replaced with an equal mass of platinum nitrate, and the rest is completely the same as Embodiment 1.

[0130] Example 4

[0131] This embodiment provides an indium-based catalyst 3% In-0.5% Ir@S-1, which differs from Embodiment 1 in that rhodium chloride is replaced with iridium chloride of equal mass, and the rest is completely the same as Embodiment 1.

[0132] Example 5

[0133] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Embodiment 1 in that indium nitrate is replaced with indium chloride of equal mass, and the rest is completely the same as Embodiment 1.

[0134] Example 6

[0135] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Embodiment 1 in that indium nitrate is replaced with indium hydroxide of equal mass, and the rest is completely the same as Embodiment 1.

[0136] Example 7

[0137] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which differs from Embodiment 1 in that rhodium chloride is replaced with rhodium nitrate of equal mass, and the rest is completely the same as Embodiment 1.

[0138] Example 8

[0139] This embodiment provides an indium-based catalyst 3% In-0.5% Au@S-1, which differs from Embodiment 1 in that rhodium chloride is replaced by chloroauric acid of equal mass, and the rest is completely the same as Embodiment 1.

[0140] Example 9

[0141] This embodiment provides an indium-based catalyst 5% In-0.1% Rh@S-1, wherein the indium-based catalyst 3% In-0.5% Rh@S-1 is prepared by the following steps:

[0142] S1. Dissolve 1 g of indium nitrate in 10 mL of water to obtain an indium metal solution; dissolve 1 g of rhodium chloride in 25 mL of a 0.32 g / mL ethylenediamine aqueous solution to obtain a metal rhodium solution;

[0143] S2, weigh 7.78g ultrapure water and 2.22g tetrapropylammonium hydroxide (TPAOH, 25wt.%), add them to 100mL hydrothermal kettle in turn, stir for 3min; add 0.06mL of the prepared metal rhodium solution, stir for 1min; then add 3.47g of tetraethyl orthosilicate (TEOS), stir for 7.5h; add 0.8mL of indium metal solution, continue stirring for 30min; heat to 170℃ at a rate of 5℃ / min, and hydrothermally react for 72h;

[0144] S3. Wash and filter the material obtained from the hydrothermal reaction, collect the solid product, dry it at 80° C. for 9 hours, and then calcine it at 550° C. for 6 hours to obtain the indium-based catalyst 5% In-0.1% Rh@S-1.

[0145] Example 10

[0146] This embodiment provides an indium-based catalyst 0.5% In-2% Rh@S-1, and the indium-based catalyst 3% In-0.5% Rh@S-1 is prepared by the following steps:

[0147] S1. Dissolve 1 g of indium nitrate in 10 mL of water to obtain an indium metal solution; dissolve 1 g of hydrated rhodium chloride in 25 mL of a 0.32 g / mL aqueous solution of ethylenediamine to obtain a metallic rhodium solution;

[0148] S2, weigh 7.78g ultrapure water and 2.22g tetrapropylammonium hydroxide (TPAOH, 25wt.%), add them to 100mL hydrothermal kettle in turn, stir for 3min; add 3mL of the prepared rhodium complex solution, stir for 1min; then add 3.47g of tetraethyl orthosilicate (TEOS), stir for 7.5h; add 0.13mL of indium metal solution, continue stirring for 30min; heat to 170℃ at a rate of 5℃ / min, and hydrothermally react for 72h;

[0149] S3. Wash and filter the material obtained from the hydrothermal reaction, collect the solid product, dry it at 80° C. for 9 hours, and then calcine it at 550° C. for 6 hours to obtain the indium-based catalyst 0.5% In-2% Rh@S-1.

[0150] Embodiment 11

[0151] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Example 1 only in that the hydrothermal reaction temperature is 150° C. and the hydrothermal reaction time is 96 h. The rest is completely consistent with Example 1.

[0152] Example 12

[0153] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Example 1 only in that the hydrothermal reaction temperature is 130° C. and the hydrothermal reaction time is 96 h. The rest is completely consistent with Example 1.

[0154] Example 13

[0155] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from the embodiment 1 only in that the calcination temperature is 450° C. and the calcination time is 10 h, and the rest is completely the same as the embodiment 1.

[0156] Embodiment 14

[0157] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Example 1 only in that the calcination temperature is 650° C. and the calcination time is 2 h. The rest is completely consistent with Example 1.

[0158] Embodiment 15

[0159] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Example 1 only in that ethyl orthosilicate is replaced by an equal mass of methyl orthosilicate, and tetrapropylammonium hydroxide is replaced by an equal mass of ethanolamine, and the rest is exactly the same as Example 1.

[0160] Example 16

[0161] This embodiment provides an indium-based catalyst 3% In-0.5% Rh@S-1, which is different from Example 1 only in that ethyl orthosilicate is replaced by an equal mass of ethyl metasilicate, and tetrapropylammonium hydroxide is replaced by an equal mass of tetraethylammonium chloride, and the rest is exactly the same as Example 1.

[0162] Comparative Example 1

[0163] This comparative example provides a commercially available CuO-ZnO-Al 2 O 3 catalyst.

[0164] Comparative Example 2

[0165] This comparative example provides a 0.5% Rh-In 2 O 3 Catalyst, the 0.5% Rh-In 2 O 3 The catalyst is prepared by the following steps:

[0166] 0.016 g Rh(NO 3 ) 3 ·2H 2 O, 1.10 g indium nitrate In(NO 3 ) 3 ·4H 2 O and 1.40 g of Na 2 CO 3 10H 2 O were dissolved in 5 mL, 20 mL and 24 mL of deionized water respectively. Then Na 2 CO 3 The aqueous solution was added dropwise with Rh(NO 3 ) 3 Aqueous solution and In(NO 3 ) 3The mixture was stirred at 80°C for 6 hours, and then the precipitate was washed with deionized water. The filtered product was dried at 80°C overnight and calcined in air at 450°C for 3 hours. The obtained product was recorded as 0.5% Rh-In 2 O 3 catalyst.

[0167] Comparative Example 3

[0168] This comparative example provides a 0.5% Pd-In 2 O 3 Catalyst, the 0.5% Pd-In 2 O 3 The catalyst is prepared by the following steps:

[0169] 0.011gPd(NO 3 ) 2 、1.10gIn(NO 3 ) 3 ·4H 2 O and 1.40g Na 2 CO 3 10H 3 O were dissolved in 5 mL, 20 mL and 24 mL of deionized water respectively. Then Na 2 CO 3 The aqueous solution was added dropwise with Pd(NO 3 ) 2 Aqueous solution and In(NO 3 ) 3 The mixture was stirred at 80°C for 6 hours, and then the precipitate was washed with deionized water. The filtered product was dried at 80°C overnight and calcined in air at 500°C for 3 hours. The obtained product was recorded as 0.5% Pd-In 2 O 3 catalyst.

[0170] Test Example 1

[0171] Test samples: catalysts provided in Examples 1 to 16, catalysts provided in Comparative Examples 1 to 3

[0172] Test method: Weigh 150 mg of each of the above catalyst samples and place them into a quartz reaction tube. 2 :H 2 =1:6) atmosphere, the temperature was raised to 290°C at a rate of 10°C / min, and after reacting for 20 hours, the reaction product was analyzed online using a gas chromatograph.

[0173] The test results are shown in Table 1 and Figure 1 As shown:

[0174] Table 1

[0175]

[0176]

[0177] It can be seen from the evaluation results of Examples 1 and 2 and Comparative Example 1 that the 3% In-0.5% Rh@S-1 and 3% In-0.5% Pd@S-1 metal confined catalysts prepared by the present invention can significantly improve the selectivity of methanol. Under the same conditions, the methanol yield is higher than that of the traditional commercial CuO-ZnO-Al 2 O 3 6% to 9% higher. In particular, when the gas mole ratio H 2 :CO 2 is 6, the temperature is 290℃, the pressure is 5Mpa, and the space velocity is 6000mL g cat -1 h -1 Under the above conditions, the carbon dioxide conversion rate can reach 25%, the methanol yield can reach 23% (close to the equilibrium yield), and the selectivity of the main by-product CO is less than 12%.

[0178] It can be seen from the evaluation results of Examples 1 and 2 and Comparative Examples 1 and 2 that the 3% In-0.5% Rh@S-1 and 3% In-0.5% Pd@S-1 metal confined catalysts prepared by the present invention can significantly improve the activity and methanol selectivity of the catalyst while reducing the amount of indium metal used, thereby effectively improving the utilization efficiency of the metal.

[0179] From Table 1 and Figure 1 It can be seen that the 3% In-0.5% Rh@S-1 metal confined catalyst prepared by the present invention has a high carbon dioxide hydrogenation activity. Within 100 hours of reaction, the catalyst is not deactivated and the reaction performance is maintained at a high level. This shows that the prepared indium-based metal confined catalyst has excellent performance in the carbon dioxide hydrogenation to methanol reaction and has good application prospects.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An indium-based catalyst, characterized in that The indium-based catalyst comprises a molecular sieve carrier and an active metal component confined within the molecular sieve; Wherein, the molecular sieve carrier is an all-silicon MFI type molecular sieve carrier; Among them, the active metal component includes a main active metal component and a precious metal additive; the main active metal component includes In, and the precious metal additive includes any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir.

2. The indium-based catalyst according to claim 1, characterized in that The indium-based catalyst is composed of the following components in terms of mass percentage: 0.5-5% of a main active metal component, 0.1-2% of a noble metal auxiliary agent, and the remainder being a molecular sieve carrier.

3. The indium-based catalyst according to claim 1 or 2, characterized in that The all-silicon MFI type molecular sieve carrier is an S-1 type all-silicon molecular sieve.

4. A method for preparing an indium-based catalyst according to any one of claims 1 to 3, characterized in that: The preparation method comprises: The indium metal compound and the noble metal compound are respectively prepared into solutions to obtain an indium metal solution and a noble metal solution; and tetraethyl orthosilicate, tetrapropylammonium hydroxide and water are mixed to obtain a mixed solution; Adding indium metal solution and noble metal solution dropwise to the mixed solution, stirring and performing a hydrothermal reaction; The product obtained by the hydrothermal reaction is washed, filtered, dried and calcined in sequence to obtain an indium-based catalyst.

5. The preparation method according to claim 4, characterized in that: The indium metal compound includes any one of indium salt, indium oxide, indium hydroxide or indium complex, or a combination of at least two thereof, preferably indium salt; Preferably, the indium salt comprises indium nitrate and / or indium halide, and more preferably indium nitrate; And / or, the noble metal compound includes any one or a combination of at least two of a noble metal salt, a noble metal oxide, a noble metal hydroxide or a noble metal complex, preferably a noble metal salt; wherein the noble metal additive includes any one or a combination of at least two of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Pt or Ir; Preferably, the noble metal salt includes any one of a noble metal nitrate, a noble metal halide or a noble metal sulfate, or a combination of at least two thereof; Preferably, the noble metal is Rh and / or Pd; Preferably, the solvent of the indium metal solution is water; Preferably, the concentration of the indium metal compound in the indium metal solution is 0.1 to 1 g / mL; Preferably, the solvent of the noble metal solution is an aqueous solution of ethylenediamine; Preferably, the concentration of ethylenediamine in the ethylenediamine aqueous solution is 0.1 to 0.5 g / mL; Preferably, the concentration of the noble metal compound in the noble metal solution is 0.01 to 0.05 g / mL.

6. The preparation method according to claim 4, characterized in that: The mass ratio of the tetraethyl orthosilicate, tetrapropylammonium hydroxide and water is (3-4):(0.8-1.2):(10-25); Preferably, the temperature for dropping the indium metal solution and the noble metal solution is 10 to 35° C.; Preferably, the stirring time is 5 to 15 hours; Preferably, the temperature of the hydrothermal reaction is 140-180°C, and the time of the hydrothermal reaction is 24-96h; Preferably, the specific steps of the hydrothermal reaction are: (a) tetrapropylammonium hydroxide and water are mixed, and a noble metal solution is added dropwise to obtain a mixed solution 1; (b) adding tetraethyl orthosilicate to the mixed solution 1 to obtain a mixed solution 2; (c) adding an indium metal solution dropwise to the mixed solution 2 to carry out a hydrothermal reaction to obtain a product; Preferably, in step (b), stirring is further performed for 5 to 15 hours after adding ethyl orthosilicate; Preferably, in step (c), stirring is further performed for 0.1 to 1 h after adding the indium metal solution; Preferably, in step (c), the heating rate of the hydrothermal reaction is 1 to 10° C. / min, the temperature of the hydrothermal reaction is 140 to 180° C., and the time of the hydrothermal reaction is 24 to 96 h.

7. The preparation method according to claim 4, characterized in that: The drying temperature is 70 to 90° C., and the drying time is 6 to 12 hours; Preferably, the calcination temperature is 450-650°C, and the calcination time is 2-10h; Preferably, the calcination further includes a molding step, wherein the molding is: tableting molding, followed by granulation molding or extrusion molding.

8. Use of the indium-based catalyst according to any one of claims 1 to 3, or the indium-based catalyst prepared by the preparation method according to any one of claims 4 to 7, in catalyzing the hydrogenation of carbon dioxide to produce methanol.

9. A method for preparing methanol by hydrogenating carbon dioxide, characterized in that: The method comprises the following steps: In the presence of an indium-based catalyst, carbon dioxide and hydrogen are reacted to prepare methanol; Wherein, the indium-based catalyst comprises the indium-based catalyst described in any one of claims 1 to 3, or the indium-based catalyst prepared by the preparation method described in any one of claims 4 to 7.

10. The method according to claim 9, characterized in that The reaction is carried out in any one of a fixed bed reactor, a moving bed reactor or a fluidized bed reactor; Preferably, the molar ratio of hydrogen to carbon dioxide is (1-30):1; Preferably, the reaction temperature is 200-350°C, and the reaction pressure is 2-10 MPa; Preferably, the space velocity of the reaction is 6000 to 12000 mL / h / g.

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