Catalyst for methane dry reforming reaction and preparation and application thereof

Abstract

The invention relates to a catalyst for methane dry reforming reaction and preparation and application thereof, the catalyst comprises an active metal, an inert porous dispersion medium and an auxiliary agent, the active metal is nickel, the inert porous dispersion medium is silicon dioxide, and the auxiliary agent is alkali metal, alkaline earth metal or rare earth metal; the preparation method comprises the following steps: adjusting the pH value of an aqueous solution containing nickel salt and a structure-directing agent by using ammonia water, then separating solids from the obtained mixture, and then adding a tetraethoxysilane-ethanol solution into the obtained colloid; after tetraethoxysilane is completely hydrolyzed, silicon dioxide solid is separated out, and the solid is washed, dried and roasted to obtain a porous NiO-coated SiO2 compound; then, an auxiliary agent is introduced into the compound through an impregnation method, and a catalyst precursor is obtained; and finally, carrying out heat treatment on the precursor in a reducing atmosphere to obtain the target catalyst. According to the present invention, the catalyst has advantages of excellent catalytic activity, excellent sintering resistance and excellent carbon deposition resistance, and can be used in reforming reactions and other reactions of hydrocarbons and oxygen-containing compounds.

Description

Technical Field

[0001] The invention belongs to the technical field of preparing synthesis gas by dry reforming of methane, and particularly relates to a catalyst for methane dry reforming reaction and a preparation and application thereof. Background Art

[0002] As the main component of natural gas, methane (CH4) is not only an important carbon-containing resource, but also the hydrocarbon compound with the highest hydrogen content. Methane reacts with simple oxygen-containing compounds, such as oxygen (O2), water (H2O) and carbon dioxide (CO2), to produce hydrogen (H2) and carbon monoxide (CO). Hydrogen and carbon monoxide can be further converted into important industrial products such as methanol, ethylene, benzene, gasoline and diesel.

[0003] The reaction of methane and carbon dioxide to produce hydrogen and carbon monoxide is called methane dry reforming. Without large-scale infrastructure reconstruction, using clean energy to convert carbon dioxide into fuels or chemicals may produce significant negative carbon emissions. Therefore, the methane dry reforming reaction has both significant environmental and economic benefits.

[0004] Methane dry reforming reaction is a highly endothermic process. From the perspective of thermodynamics and kinetics, high temperature is not only conducive to improving the yield of synthesis gas, but also conducive to the rapid conversion of reactants. In order to increase the synthesis gas generation rate, the participation of solid catalysts is usually required.

[0005] Studies have found that most Group VIII metals can catalyze methane dry reforming reactions. At present, the active components used as solid catalysts for methane dry reforming are platinum group metals and cheap metals such as iron, cobalt and nickel. Platinum group metals have excellent catalytic performance, but the high cost problem greatly limits their commercial application. Non-precious metals, especially nickel, show good application potential due to their low price and high activity. For example, the patent application with publication number CN107282086A discloses a catalyst for catalyzing methane dry reforming reactions and its preparation method and application, wherein the catalyst is a BA / C catalyst obtained by using an oxide as a carrier C to load two metals A and B, and the catalyst is sequentially loaded with two metals A and B by an impregnation method and a redox substitution method between metals and metal cations, wherein metal A is Ni or Cu, metal B is Rh or Pt, and carrier C is Al2O3, SiO2, ZrO2 or SBA-15. However, compared with precious metals, metal Ni is prone to sintering and carbon deposition, which limits its large-scale application.

[0006] Therefore, how to effectively improve the anti-sintering and anti-carbon deposition performance of nickel-based catalysts is a bottleneck problem that urgently needs to be solved. Summary of the invention

[0007] In view of the bottleneck problems of the above-mentioned prior art, the present invention aims to provide a catalyst for methane dry reforming reaction and its preparation and application, which uniformly isolates nickel nanoparticles in a porous silica matrix so that it has excellent catalytic activity and also has excellent resistance to sintering and carbon deposition, thereby realizing stable and efficient activation and directional recombination of methane and carbon dioxide.

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

[0009] A catalyst for methane dry reforming reaction, composed of an active metal, an inert porous dispersion medium and an auxiliary agent, the mass fractions of the three components are 2-20 parts, 80-95 parts and 0.1-2.5 parts, the active metal is nickel; the inert porous dispersion medium is silicon dioxide; the auxiliary agent is an alkali metal, an alkaline earth metal or a rare earth metal.

[0010] The present invention also discloses a method for preparing the methane dry reforming catalyst, comprising the following steps:

[0011] (1) adding a soluble nickel salt to pure water and stirring the water sufficiently to completely dissolve the nickel salt to obtain a solution A;

[0012] (2) adding a structure directing agent to the above solution A, stirring it thoroughly to dissolve it completely, and obtaining a solution B; the structure directing agent is one or more of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, and cetyltrimethylammonium p-toluenesulfonate in any ratio;

[0013] (3) adjusting the pH of solution B to alkaline and allowing to stand overnight to obtain a mixture;

[0014] (4) separating the solid from the mixture to obtain colloid C;

[0015] (5) adding tetraethyl orthosilicate to ethanol and stirring thoroughly to completely dissolve it to obtain solution D;

[0016] (6) Add solution D dropwise to colloid C and stir thoroughly to mix the two to obtain solution E;

[0017] (7) After the solution E is continuously stirred for 0.5 h to 24 h, a solid-liquid mixture is obtained; during the stirring, the temperature of the solution E is maintained at 10° C. to 60° C.;

[0018] (8) separating the solid-liquid mixture, and washing the obtained filter cake repeatedly with an ethanol-water solution;

[0019] (9) The washed filter cake is first dried at a temperature of 60°C to 150°C for a drying time of 3h to 24h, and then calcined at a temperature of 300°C to 600°C for a calcination time of 3h to 24h to obtain a porous solid, which is recorded as F powder;

[0020] (10) dissolving the auxiliary agent precursor in pure water to obtain a solution G; adding the solution G dropwise to the porous solid F powder to form a paste; the auxiliary agent precursor is one or more soluble compounds of alkali metals, alkaline earth metals, and rare earth metals in any ratio;

[0021] (11) The paste is first placed in the shade at room temperature for 24 hours to 96 hours; then dried at a temperature of 60°C to 150°C for 3 hours to 24 hours; and finally calcined at a temperature of 500°C to 900°C for 3 hours to 24 hours to obtain a catalyst precursor powder;

[0022] (12) The catalyst precursor powder is loaded into a fixed bed reactor, and a reducing gas is introduced for reduction, wherein the ratio of the reducing gas flow rate to the catalyst precursor powder is 100 mL / min·g to 10000 mL / min·g; and a nickel-based catalyst for dry reforming of methane to produce synthesis gas is obtained.

[0023] In the step (1):

[0024] The nickel salt is one or more of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate, preferably nickel nitrate;

[0025] The concentration of nickel in the solution A is 0.01M to 1M, preferably 0.03M to 0.25M.

[0026] In the step (2):

[0027] The structure directing agent is preferably hexadecyltrimethylammonium bromide;

[0028] The concentration of the structure directing agent in the solution B is 0.01M to 0.5M, preferably 0.02M to 0.2M;

[0029] In the step (3):

[0030] The alkali solution for adjusting pH is concentrated ammonia water, and the pH of solution B is adjusted to 8-12, preferably 8.5-10.5;

[0031] While standing, the temperature of solution B is maintained at 10°C to 60°C, preferably 20°C to 40°C.

[0032] In the step (5), the mass fraction of ethyl orthosilicate in solution D is 5% to 50%, preferably 10% to 30%.

[0033] In the step (6), colloid C and solution D are mixed at room temperature, and the volume ratio of the colloid C and solution D is 2-5.

[0034] In the step (7), the stirring time is preferably 0.5 h to 10 h; during stirring, the temperature of the solution E is maintained at 20° C. to 40° C.

[0035] In the step (9), the drying atmosphere is air; the drying temperature is 80°C to 120°C; the drying time is 12h to 18h; the roasting temperature is 400°C to 550°C; the roasting time is 12h to 18h; and the roasting atmosphere is air.

[0036] In the step (10):

[0037] The auxiliary agent precursor is preferably potassium or cerium;

[0038] The ratio of the volume of the pure water to the pore volume of the solid F powder is 1:1;

[0039] The mass of the auxiliary agent is 1% to 10% of the mass of the solid F powder, preferably 2% to 5%;

[0040] The porous solid F powder is pre-vacuumed.

[0041] In the step (11):

[0042] The paste is dried in the shade for 36 hours to 72 hours;

[0043] The drying temperature is 80°C to 120°C, the drying time is 12h to 18h, and the drying atmosphere is air;

[0044] The calcination temperature is 600° C. to 800° C., the calcination time is 12 h to 18 h, and the calcination atmosphere is air.

[0045] The step (12) is specifically as follows:

[0046] The reducing gas is a mixture of hydrogen and an inert gas, and the inert gas is one or more combinations of nitrogen, helium, and argon, preferably helium;

[0047] The ratio of the reducing gas flow rate to the catalyst precursor powder is 500 mL / min·g to 5000 mL / min·g; the volume content of hydrogen in the reducing gas is 1% to 50%, preferably 5% to 25%;

[0048] The reduction temperature is 600°C to 1000°C, preferably 700°C to 950°C;

[0049] The reduction time is 0.25h to 6h, preferably 0.5h to 3h.

[0050] The invention discloses an application of a catalyst for methane dry reforming reaction, which is used in the reforming reaction of hydrocarbons and oxygen-containing compounds.

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

[0052] (1) The addition of the structure directing agent in step 2 of the present invention, as well as the subsequent preparation and combustion processes, makes the porous solid obtained in step 9 a porous silica matrix, so that the nickel nanoparticles of the nickel salt in step 1 are evenly isolated in the porous silica matrix, which not only makes it have excellent catalytic activity, but also makes it have excellent anti-sintering and anti-carbon deposition capabilities.

[0053] (2) The catalyst obtained by the present invention is prepared using cheap and readily available chemicals and common unit operations in the entire preparation process. The catalyst manufacturing cost is low, the preparation method is simple and easy, the preparation conditions are easy to accurately control, and the preparation process has high repeatability.

[0054] (3) The catalyst obtained by the present invention can be widely used in the reforming reaction of hydrocarbons and oxygen-containing compounds and has extremely strong adaptability.

[0055] In summary, the catalyst of the present invention isolates nickel nanoparticles uniformly in a porous silica matrix, so that it has excellent catalytic activity, and also has excellent resistance to sintering and carbon deposition, thereby achieving stable and efficient activation and directional recombination of methane and carbon dioxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 The figure is a flowchart of the process for preparing the nickel-based catalyst precursor according to the present invention.

[0057] Figure 2 This is a graph showing the change trend of methane and carbon dioxide conversion rates versus reaction time in Example 1.

[0058] Figure 3 This is the structure and morphology of the nickel-based catalyst described in Example 2 of the present invention. DETAILED DESCRIPTION

[0059] The process technology of the present invention is clearly and completely described below in conjunction with the examples. However, it will be understood by those skilled in the art that the following described embodiments are part of the present invention rather than all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of use of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention. Those who do not specify the specific conditions in the embodiments are used according to conventional conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are all conventional products that can be purchased commercially.

[0060] The features and performance of the present invention are further described in detail below in conjunction with the embodiments:

[0061] Example 1

[0062] This embodiment discloses a method for preparing the methane dry reforming catalyst, referring to Figure 1 , including the following steps:

[0063] (1) Weigh 5.8 g of nickel nitrate hexahydrate, add it to 200 mL of pure water, and stir at room temperature to completely dissolve the nickel salt to obtain a nickel salt aqueous solution;

[0064] (2) heating the aqueous solution, and then adding 3.6 g of hexadecyltrimethylammonium bromide to the hot aqueous solution. The aqueous solution is heated to promote the dissolution of the structure-directing agent hexadecyltrimethylammonium bromide, and the solution is stirred sufficiently to completely dissolve the structure-directing agent hexadecyltrimethylammonium bromide to obtain a three-component solution.

[0065] (3) After the three-component solution is cooled to room temperature, the pH of the three-component solution is adjusted to 8.6 with concentrated aqueous ammonia, and then the solution is placed in a constant temperature water bath at 20° C. and allowed to stand overnight to obtain a mixture;

[0066] (4) At room temperature, separate the solids in the mixture using a high-speed centrifuge and collect the colloid for later use;

[0067] (5) adding 1.8 g of tetraethyl orthosilicate to 13.6 g of ethanol, and stirring at room temperature to completely dissolve the tetraethyl orthosilicate to obtain an alcohol solution;

[0068] (6) heating the colloid to 40° C. and then adding the alcohol solution while stirring;

[0069] (7) After the addition was completed, the temperature was kept constant and stirring was continued for 6 h to obtain a suspension;

[0070] (8) At room temperature, the suspension was separated into solid and liquid using a high-speed centrifuge, and the obtained solid was washed with pure water and ethanol in turn;

[0071] (9) The solid was then dried at 100°C overnight and finally calcined at 450°C for 16 h to obtain a porous solid powder. The drying and calcination were both carried out in an air atmosphere.

[0072] (10) Weigh 0.1 g of potassium hydroxide, add it to 4 mL of pure water, and stir at room temperature to completely dissolve the potassium hydroxide to obtain an impregnation solution; add the impregnation solution dropwise to 5 g of the porous solid powder to form a paste;

[0073] (11) The paste was dried in a ventilated place at room temperature for 4 days; then dried at 120° C. overnight, and finally calcined at 800° C. for 12 h to obtain a catalyst precursor; the drying and calcination were both carried out in an air atmosphere;

[0074] (12) Place 0.03 g of catalyst precursor powder in a quartz tube with an inner diameter of 10 mm, and place the quartz tube in a high-temperature vertical electric furnace; introduce 30 mL / min of a binary mixture of argon and hydrogen into the quartz tube, with the hydrogen volume fraction in the mixture being 10%; then increase the temperature of the electric furnace to 800°C at a heating rate of 10°C / min, and after maintaining this temperature for 1 hour, reduce the temperature of the electric furnace to 750°C, switch the mixture of argon and hydrogen to pure argon, purge with pure argon for 0.25 hours, and then switch to a ternary mixture of argon, methane and carbon dioxide; the molar ratio of argon:methane:carbon dioxide in the mixture is 4:3:3, and the flow rate is 20 mL / min; the gas composition at the outlet of the quartz tube is analyzed online by a gas chromatograph equipped with a thermal conductivity cell detector to obtain the target catalyst powder. Figure 2 As shown, the methane and carbon dioxide conversion rates hardly decreased within a reaction time of 50 hours.

[0075] Example 2

[0076] This embodiment discloses a method for preparing the methane dry reforming catalyst, referring to Figure 1 , including the following steps:

[0077] (1) Weigh 3 g of nickel nitrate hexahydrate, add it to 200 mL of pure water, and stir at room temperature to completely dissolve the nickel salt to obtain a nickel salt aqueous solution;

[0078] (2) heating the aqueous solution, then adding 5 g of hexadecyltrimethylammonium chloride to the hot aqueous solution, stirring it thoroughly to completely dissolve it, to obtain a three-component solution;

[0079] (3) After the three-component solution is cooled to room temperature, the pH of the three-component solution is adjusted to 8.8 with concentrated ammonia water, and then the solution is placed in a constant temperature water bath at 20° C. and allowed to stand overnight to obtain a mixture;

[0080] (4) At room temperature, separate the solids in the mixture using a high-speed centrifuge and collect the colloid for later use;

[0081] (5) adding 2 g of tetraethyl orthosilicate to 15 g of ethanol, stirring at room temperature to completely dissolve the tetraethyl orthosilicate, to obtain an alcohol solution;

[0082] (6) Heat the colloid to 30°C, and then add the alcohol solution while stirring;

[0083] (7) After the addition was completed, the temperature was kept constant and stirring was continued for 6 h to obtain a suspension;

[0084] (8) At room temperature, the suspension was separated into solid and liquid using a high-speed centrifuge, and the obtained solid was washed with pure water and ethanol in turn;

[0085] (9) The solid was then dried at 90° C. overnight, and finally calcined at 550° C. for 12 h to obtain a porous solid powder; the drying and calcining were both carried out in an air atmosphere;

[0086] (10) Weigh 0.05 g of potassium carbonate, add it to 4 mL of pure water, and stir at room temperature to completely dissolve the potassium salt to obtain an impregnation solution; add the impregnation solution dropwise to 5 g of the porous solid powder to form a paste;

[0087] (11) The paste was dried in a ventilated place at room temperature for 3 days; then dried at 120° C. overnight, and finally calcined at 750° C. for 15 h to obtain a catalyst precursor; the drying and calcination were both carried out in an air atmosphere;

[0088] (12) 0.1 g of catalyst precursor powder was placed in a quartz tube with an inner diameter of 10 mm, and the quartz tube was placed in a high-temperature vertical electric furnace; 50 mL / min of a binary mixture of argon and hydrogen was introduced into the quartz tube, and the volume fraction of hydrogen in the mixture was 15%; then the temperature of the electric furnace was increased to 800°C at a heating rate of 10°C / min, and after maintaining this temperature for 0.5 h, the electric furnace was naturally cooled to obtain the target catalyst powder. Figure 3 As shown, the nickel nanoparticles in the catalyst are isolated in a porous silica matrix.

[0089] Example 3

[0090] This embodiment discloses a method for preparing the methane dry reforming catalyst, referring to Figure 1 , including the following steps:

[0091] (1) Weigh 5 g of nickel acetate tetrahydrate, add it to 200 mL of pure water, and stir at room temperature to completely dissolve the nickel salt to obtain a nickel salt aqueous solution;

[0092] (2) heating the aqueous solution, then adding 4 g of hexadecyltrimethylammonium bromide to the hot aqueous solution, stirring it thoroughly to completely dissolve it, to obtain a three-component solution;

[0093] (3) After the three-component solution is cooled to room temperature, the pH of the three-component solution is adjusted to 8.4 with concentrated aqueous ammonia, and then the solution is placed in a constant temperature water bath at 20° C. and allowed to stand overnight to obtain a mixture;

[0094] (4) At room temperature, separate the solids in the mixture using a high-speed centrifuge and collect the colloid for later use;

[0095] (5) adding 3 g of tetraethyl orthosilicate to 15 g of ethanol and stirring at room temperature to completely dissolve the tetraethyl orthosilicate to obtain an alcohol solution;

[0096] (6) heating the colloid to 35° C. and then adding the alcohol solution while stirring;

[0097] (7) After the addition was completed, the temperature remained unchanged and stirring was continued for 4 h to obtain a suspension;

[0098] (8) At room temperature, the suspension was separated into solid and liquid using a high-speed centrifuge, and the obtained solid was washed with pure water and ethanol in turn;

[0099] (9) The solid was then dried at 100° C. overnight, and finally calcined at 450° C. for 12 h to obtain a porous solid powder; the drying and calcining were both carried out in an air atmosphere;

[0100] (10) Weigh 0.8 g of cerium nitrate hexahydrate, add it to 4 mL of pure water, and stir at room temperature to completely dissolve the cerium salt to obtain an impregnation solution; add the impregnation solution dropwise to 5 g of the porous solid powder to form a paste;

[0101] (11) The paste was dried in a ventilated place at room temperature for 2 days; then dried at 100° C. overnight, and finally calcined at 800° C. for 15 h to obtain a catalyst precursor; the drying and calcination were both carried out in an air atmosphere;

[0102] (12) 0.25 g of catalyst precursor powder was placed in a quartz tube with an inner diameter of 10 mm, and the quartz tube was placed in a high-temperature vertical electric furnace; 100 mL / min of a binary mixture of argon and hydrogen was introduced into the quartz tube, and the volume fraction of hydrogen in the mixture was 10%; then the temperature of the electric furnace was increased to 800 °C at a heating rate of 10 °C / min, and after maintaining this temperature for 1 hour, the electric furnace was naturally cooled to obtain the target catalyst powder.

[0103] Example 4

[0104] This embodiment discloses a method for preparing the methane dry reforming catalyst, referring to Figure 1 , including the following steps:

[0105] (1) Weigh 6 g of nickel nitrate hexahydrate, add it to 200 mL of pure water, and stir at room temperature to completely dissolve the nickel salt to obtain a nickel salt aqueous solution;

[0106] (2) heating the aqueous solution, then adding 4 g of hexadecyltrimethylammonium bromide to the hot aqueous solution, stirring it thoroughly to completely dissolve it, to obtain a three-component solution;

[0107] (3) After the three-component solution is cooled to room temperature, the pH of the three-component solution is adjusted to 8.8 with concentrated ammonia water, and then the solution is placed in a constant temperature water bath at 35° C. and allowed to stand overnight to obtain a mixture;

[0108] (4) At room temperature, separate the solids in the mixture using a high-speed centrifuge and collect the colloid for later use;

[0109] (5) adding 3 g of tetraethyl orthosilicate to 15 g of ethanol and stirring at room temperature to completely dissolve the tetraethyl orthosilicate to obtain an alcohol solution;

[0110] (6) heating the colloid to 35° C. and then adding the alcohol solution while stirring;

[0111] (7) After the addition was completed, the temperature was kept constant and stirring was continued for 6 h to obtain a suspension;

[0112] (8) At room temperature, the suspension was separated into solid and liquid using a high-speed centrifuge, and the obtained solid was washed with pure water and ethanol in turn;

[0113] (9) The solid was then dried at 100° C. overnight and finally calcined at 500° C. for 8 h to obtain a porous solid powder; the drying and calcining were both carried out in an air atmosphere;

[0114] (10) Weigh 0.6 g of cerium nitrate hexahydrate, add it to 4 mL of pure water, and stir at room temperature to completely dissolve the cerium salt to obtain an impregnation solution;

[0115] Add the impregnation liquid dropwise to 5 g of porous solid powder to form a paste;

[0116] (11) The paste was dried in a ventilated place at room temperature for 2 days; then dried at 100° C. overnight, and finally calcined at 800° C. for 15 h to obtain a catalyst precursor; the drying and calcination were both carried out in an air atmosphere;

[0117] (12) 0.1 g of catalyst precursor powder was placed in a quartz tube with an inner diameter of 10 mm, and the quartz tube was placed in a high-temperature vertical electric furnace; 50 mL / min of a binary mixture of argon and hydrogen was introduced into the quartz tube, and the volume fraction of hydrogen in the mixture was 10%; then the temperature of the electric furnace was increased to 800 °C at a heating rate of 10 °C / min, and after maintaining this temperature for 1 hour, the electric furnace was naturally cooled to obtain the target catalyst powder.

[0118] Example 5

[0119] This embodiment discloses a method for preparing the methane dry reforming catalyst, referring to Figure 1 , including the following steps:

[0120] (1) Weigh 3 g of nickel nitrate hexahydrate and 2.5 g of nickel acetate tetrahydrate, add them to 100 mL of pure water, and stir at room temperature to completely dissolve the nickel salt to obtain a nickel salt aqueous solution;

[0121] (2) heating the aqueous solution, then adding 1.5 g of hexadecyltrimethylammonium bromide and 2 g of hexadecyltrimethylammonium chloride to the hot aqueous solution, stirring them thoroughly to completely dissolve them, to obtain a four-component solution;

[0122] (3) After the four-component solution is cooled to room temperature, the pH of the four-component solution is adjusted to 8.6 with concentrated ammonia water, and then the solution is placed in a constant temperature water bath at 35° C. and allowed to stand overnight to obtain a mixture;

[0123] (4) At room temperature, separate the solids in the mixture using a high-speed centrifuge and collect the colloid for later use;

[0124] (5) adding 3 g of tetraethyl orthosilicate to 15 g of ethanol and stirring at room temperature to completely dissolve the tetraethyl orthosilicate to obtain an alcohol solution;

[0125] (6) heating the colloid to 35° C. and then adding the alcohol solution while stirring;

[0126] (7) After the addition was completed, the temperature was kept constant and stirring was continued for 6 h to obtain a suspension;

[0127] (8) At room temperature, the suspension is separated into solid and liquid using a high-speed centrifuge, and the obtained solid is washed with pure water and ethanol in sequence;

[0128] (9) The solid was then dried at 100° C. overnight and finally calcined at 500° C. for 8 h to obtain a porous solid powder; the drying and calcining were both carried out in an air atmosphere;

[0129] (10) Weigh 0.8 g of cerium nitrate hexahydrate, add it to 8 mL of pure water, and stir at room temperature to completely dissolve the cerium salt to obtain an impregnation solution A; add the impregnation solution A dropwise to 10 g of the porous solid powder to form a paste;

[0130] (11) The paste was dried in the shade in a ventilated place at room temperature for 2 days; then dried at 100°C overnight, and finally calcined at 600°C for 12 hours to obtain catalyst precursor B; both drying and calcining were carried out in an air atmosphere; 0.05 g of potassium carbonate was weighed, added to 4 mL of pure water, and stirred at room temperature to completely dissolve the potassium salt to obtain an impregnation solution B; the impregnation solution B was added dropwise to 5 g of catalyst precursor B to form a paste; the paste was dried in the shade in a ventilated place at room temperature for 3 days; then dried at 120°C overnight, and finally calcined at 800°C for 12 hours to obtain catalyst precursor C; both drying and calcining were carried out in an air atmosphere;

[0131] (12) 0.1 g of precursor C was placed in a quartz tube with an inner diameter of 10 mm, and the quartz tube was placed in a high-temperature vertical electric furnace; 80 mL / min of a mixture of argon and hydrogen was introduced into the quartz tube, and the hydrogen volume fraction in the mixture was 10%; then the temperature of the electric furnace was increased to 800°C at a heating rate of 10°C / min, and after maintaining this temperature for 1 hour, the electric furnace was naturally cooled to obtain the target catalyst powder.

[0132] The catalysts of the above five embodiments can all be used for reforming reactions of hydrocarbons and oxygen-containing compounds, such as propane reforming, ethanol reforming and biomass tar reforming, and have extremely strong adaptability.

Claims

1. A catalyst for methane dry reforming reaction, characterized in that: The invention is composed of active metal, inert porous dispersion medium and auxiliary agent, wherein the mass proportions of the three components are 2-20 parts, 80-95 parts and 0.1-2.5 parts respectively. The active metal is soluble nickel; the inert porous dispersion medium is silicon dioxide; and the auxiliary agent is alkali metal, alkaline earth metal or rare earth metal.

2. A method for preparing the methane dry reforming catalyst according to claim 1, characterized in that: The following steps are involved: (1) adding a soluble nickel salt to pure water and stirring the water sufficiently to completely dissolve the nickel salt to obtain a solution A; (2) adding a structure directing agent to the above solution A, stirring it thoroughly to dissolve it completely, and obtaining a solution B; the structure directing agent is one or more of cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, and cetyltrimethylammonium p-toluenesulfonate in any ratio; (3) adjusting the pH of solution B to alkaline and allowing to stand overnight to obtain a mixture; (4) separating the solid from the mixture to obtain colloid C; (5) adding tetraethyl orthosilicate to ethanol and stirring thoroughly to completely dissolve it to obtain solution D; (6) Add solution D dropwise to colloid C and stir thoroughly to mix the two to obtain solution E; (7) After the solution E is continuously stirred for 0.5 h to 24 h, a solid-liquid mixture is obtained; during the stirring, the temperature of the solution E is maintained at 10° C. to 60° C.; (8) separating the solid-liquid mixture, and washing the obtained filter cake repeatedly with an ethanol-water solution; (9) The washed filter cake is first dried at a temperature of 60°C to 150°C for a drying time of 3h to 24h, and then calcined at a temperature of 300°C to 600°C for a calcination time of 3h to 24h to obtain a porous solid, which is recorded as F powder; (10) dissolving the additive precursor in pure water to obtain solution G; The solution G is added dropwise to the porous solid F powder to form a paste; the additive precursor is one or more combinations of soluble compounds of alkali metals, alkaline earth metals and rare earth metals in any ratio; (11) The paste is first placed in the shade at room temperature for 24 hours to 96 hours; then dried at a temperature of 60°C to 150°C for 3 hours to 24 hours; and finally calcined at a temperature of 500°C to 900°C for 3 hours to 24 hours to obtain a catalyst precursor powder; (12) The catalyst precursor powder is loaded into a fixed bed reactor, and a reducing gas is introduced for reduction, wherein the ratio of the reducing gas flow rate to the catalyst precursor powder is 100 mL / min·g to 10000 mL / min·g; and a nickel-based catalyst for dry reforming of methane to produce synthesis gas is obtained.

3. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (1): The nickel salt is one or more of nickel nitrate, nickel chloride, nickel sulfate, and nickel acetate, preferably nickel nitrate; The concentration of nickel in the solution A is 0.01M to 1M, preferably 0.03M to 0.25M; In the step (2): The structure directing agent is preferably hexadecyltrimethylammonium bromide; The concentration of the structure directing agent in the solution B is 0.01M to 0.5M, preferably 0.02M to 0.2M.

4. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (3): The alkali solution for adjusting pH is concentrated ammonia water, and the pH of solution B is adjusted to 8-12, preferably 8.5-10.5; When standing, the temperature of solution B is maintained at 10°C to 60°C, preferably 20°C to 40°C; In the step (5), the mass fraction of ethyl orthosilicate in solution D is 5% to 50%, preferably 10% to 30%.

5. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (6), colloid C and solution D are mixed at room temperature, and the volume ratio of the colloid C and solution D is 2 to 5; In the step (7), the stirring time is preferably 0.5 h to 10 h; during stirring, the temperature of the solution E is maintained at 20° C. to 40° C.

6. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (9), the drying atmosphere is air; the drying temperature is 80°C to 120°C; the drying time is 12h to 18h; the roasting temperature is 400°C to 550°C; the roasting time is 12h to 18h; and the roasting atmosphere is air.

7. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (10): The auxiliary agent precursor is preferably potassium or cerium; The ratio of the volume of the pure water to the pore volume of the solid F powder is 1:1; The mass of the auxiliary agent is 1% to 10% of the mass of the solid F powder, preferably 2% to 5%; The porous solid F powder is pre-vacuumed.

8. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: In the step (11): The paste is dried in the shade for 36 hours to 72 hours; The drying temperature is 80°C to 120°C, the drying time is 12h to 18h, and the drying atmosphere is air; The calcination temperature is 600° C. to 800° C., the calcination time is 12 h to 18 h, and the calcination atmosphere is air.

9. The method for preparing a methane dry reforming catalyst according to claim 2, characterized in that: The step (12) is specifically as follows: The reducing gas is a mixture of hydrogen and an inert gas, and the inert gas is one or more combinations of nitrogen, helium, and argon, preferably helium; The ratio of the reducing gas flow rate to the catalyst precursor powder is 500 mL / min·g to 5000 mL / min·g; the volume content of hydrogen in the reducing gas is 1% to 50%, preferably 5% to 25%; The reduction temperature is 600°C to 1000°C, preferably 700°C to 950°C; The reduction time is 0.25h to 6h, preferably 0.5h to 3h.

10. Use of a catalyst for methane dry reforming reaction according to claims 1-10, characterized in that: Used in reforming reactions of hydrocarbons and oxygen-containing compounds.

Images