Formed catalyst for Ru-based ammonia synthesis promoted by charcoal ash, preparation method of formed catalyst and application of formed catalyst in green ammonia preparation

Abstract

The invention discloses a forming catalyst for Ru-based ammonia synthesis promoted by charcoal ash, a preparation method of the forming catalyst and application of the forming catalyst in green ammonia preparation. The formed activated carbon carrier is prepared from the following raw materials: a carbon source, charcoal ash and an adhesive, the formed catalyst comprises the formed activated carbon carrier, active metal Ru and an auxiliary agent. The formed catalyst provided by the invention shows excellent ammonia synthesis catalytic performance; the molding catalyst provided by the invention has the advantages of cheap raw materials in the molding process and easiness in large-scale preparation, and has a relatively strong industrial application prospect.

Description

Technical Field

[0001] The present invention relates to the field of catalyst material preparation, a shaped catalyst for Ru-based ammonia synthesis promoted by carbon ash, a preparation method thereof, and an application thereof in green ammonia production. Background Art

[0002] Ammonia (NH3) is one of the most important bulk chemicals related to the national economy and people's livelihood. It is not only the main raw material for fertilizer production but also a new hydrogen storage carrier. The traditional industrial Haber-Bosch method for ammonia synthesis requires harsh reaction conditions, operating at high temperature (≥430 °C) and high pressure (15 - 30 MPa), resulting in high energy consumption, which accounts for about 2% of the global total energy consumption every year. Therefore, it is particularly important to develop mild and efficient ammonia synthesis catalysts. The difficulties in industrial ammonia synthesis are as follows: (1) The dissociation energy of N≡N is relatively high (945 kJ mol -1 ) and it is difficult to be activated at low temperature and low pressure; (1) There is a restrictive relationship between the dissociation energy of N2 and the desorption energy of intermediate species (NH x ). Adding appropriate promoters can reduce the activation energy required for N2 dissociation on the catalyst, thereby achieving the goal of ammonia synthesis under mild conditions. Traditional promoters are generally metal promoters such as alkali metals (Na, K, and Cs), alkaline earth metals (Mg, Ca, and Ba), and rare earth metals (La, Ce, and Sm), which can transfer electrons to Ru to promote N2 dissociation. However, carbon ash (mainly composed of C 60 and C 70 ) can not only release electrons but also absorb electrons on Ru after N2 dissociation to promote NH3 desorption. The team of Jiang Lilong from Fuzhou University has demonstrated the advantages of C 60 as a promoter: (1) C 60 as an "electron buffer" can reversibly store and release electrons to balance the electron density of transition metal sites; (2) The size of C 60 is comparable to that of transition metal active catalytic sites, which helps to construct precisely separated N2 and H2 activation sites, thereby optimizing the activation and migration paths of N2 and H2. These characteristics make it possible for C 60 -TM to achieve efficient ammonia synthesis. However, when using C 60 as a carrier, there are still the following problems: The preparation process is relatively complex, resulting in too high preparation costs and it is difficult to achieve industrial application value. Therefore, in order to further improve the catalytic performance of industrial ammonia synthesis catalysts and realize the application of new Ru-based catalysts, we designed a Ru-based ammonia synthesis catalyst co-promoted by carbon ash (C 60 and C 70 ) and metal promoters (such as alkali metals, alkaline earth metals, and rare earth metals) to achieve efficient, mild and green ammonia synthesis. Summary of the Invention

[0003] To solve the above technical problems, the present invention provides the following technical solutions:

[0004] A formed activated carbon carrier, wherein the raw materials of the formed activated carbon carrier include a carbon source, carbon ash, and a binder.

[0005] According to an embodiment of the present invention, the carbon source is selected from at least one of powdered activated carbon AC (for example, purchased from Fujian Xinsen Carbon Industry Co., Ltd.) and carrier NC.

[0006] According to an embodiment of the present invention, the carbon ash includes C 60 and / or C 70 and, for example, is C 60 .

[0007] According to an embodiment of the present invention, the carbon ash accounts for 2-8 wt.%, 4 wt.%, 6 wt.% of the mass of the carbon source.

[0008] According to an embodiment of the present invention, the binder is selected from at least one or more of starch, high-temperature graphite binder, sesbania powder, activated carbon, glycerol, oxalic acid, citric acid, silica sol, aluminum sol, nitric acid, polyethylene glycol, polyvinyl alcohol, cellulose, formic acid, acetic acid, hydrochloric acid, etc.

[0009] According to an embodiment of the present invention, the binder accounts for 2-8 wt.%, for example, 4 wt.%, 6 wt.% of the mass of the carbon source.

[0010] According to an embodiment of the present invention, the formed activated carbon carrier is selected from at least one of a cylindrical shape, a clover shape, and a spherical shape.

[0011] According to an embodiment of the present invention, the dimensions of the cylindrical formed activated carbon carrier: the outer dimension length is about 3-10 mm, and the diameter is about 3-5 mm; the dimensions of the clover-shaped formed activated carbon carrier: the outer dimension length is about 3-10 mm, and the diameter is about 3-5 mm; the dimensions of the spherical formed activated carbon carrier: the diameter is about 3-5 mm.

[0012] The present invention also provides a forming process for the above-mentioned formed activated carbon carrier, and the forming process includes: after mixing the carbon source, carbon ash, and binder, carrying out kneading, then forming, and then performing drying treatment and sintering treatment to obtain the formed activated carbon carrier.

[0013] According to an embodiment of the present invention, before mixing, the carbon source is further crushed and optionally screened, for example, screened through 200-500 mesh.

[0014] According to an embodiment of the present invention, a dispersant, such as water, can also be added during mixing.

[0015] According to an embodiment of the present invention, the shaping is to obtain the shape of the desired shaped activated carbon carrier, such as cylindrical, spherical or clover-shaped.

[0016] According to an embodiment of the present invention, the shaping can be carried out by using methods known in the art, such as extrusion molding and / or extrusion-spheronization molding.

[0017] According to an embodiment of the present invention, the drying treatment is specifically drying at 80-150 °C for 12-24 h (such as 12 h, 20 h).

[0018] According to an embodiment of the present invention, the sintering treatment includes sintering in an N2 atmosphere for 2-12 h (such as 5 h, 10 h). Preferably, the sintering temperature is 400-900 °C, such as 500 °C, 600 °C, 700 °C, 800 °C.

[0019] The present invention also provides a shaped catalyst, which includes: a shaped activated carbon carrier, an active metal Ru and a promoter.

[0020] According to an embodiment of the present invention, in the shaped catalyst, the mass of Ru accounts for 1-10 wt.% of the total mass of the shaped activated carbon carrier, such as 2 wt.%, 4 wt.%, 6 wt.%, 8 wt.%.

[0021] According to an embodiment of the present invention, the promoter is selected from at least one of alkali metals, alkaline earth metals and rare earth metals.

[0022] According to an embodiment of the present invention, the content of the promoter accounts for 0-20 wt.% of the total mass of the shaped activated carbon carrier, such as 5 wt.%, 10 wt.%, 15 wt.%.

[0023] According to an embodiment of the present invention, in the shaped catalyst, the alkali metal is selected from at least one of Na, K and Cs.

[0024] According to an embodiment of the present invention, in the shaped catalyst, the alkaline earth metal is selected from at least one of Mg, Ca and Ba.

[0025] According to an embodiment of the present invention, in the shaped catalyst, the rare earth metal is selected from at least one of La, Ce and Sm.

[0026] Exemplarily, when the promoter is selected from alkali metals, the alkali metal accounts for 5-20 wt.% of the total mass of the shaped activated carbon carrier, such as 10 wt.%, 15 wt.%.

[0027] Exemplarily, when the promoter is selected from alkaline earth metals, the alkaline earth metal accounts for 4-16 wt.%, 5 wt.%, 10 wt.%, or 15 wt.% of the total mass of the shaped activated carbon support.

[0028] Exemplarily, when the promoter is selected from rare earth metals, the rare earth metal accounts for 0-5 wt.%, such as 1 wt.%, 2 wt.%, 3 wt.%, or 4 wt.% of the total mass of the shaped activated carbon support.

[0029] The present invention also provides a method for preparing the above-mentioned shaped catalyst, and the preparation method includes:

[0030] (1) Preparing a shaped activated carbon support loaded with active metal Ru: After mixing the shaped activated carbon support and a compound containing active metal (Ru), drying is carried out; preferably, calcination treatment and reduction treatment can also be carried out after drying;

[0031] (2) Preparing a shaped activated carbon support loaded with active metal Ru and a promoter: Mixing a compound containing the promoter with the shaped activated carbon support loaded with active metal Ru in step (1), and carrying out drying;

[0032] (3) After successively carrying out calcination treatment and reduction treatment on the shaped activated carbon support loaded with active metal Ru and the promoter in step (2), the shaped catalyst is obtained.

[0033] According to the embodiments of the present invention, in steps (1)-(3), the drying conditions can be the same or different. Preferably, the drying conditions are selected to be drying at 80-150 °C for 6-24 h.

[0034] According to the embodiments of the present invention, in step (2), the compound containing the promoter is selected from at least one of a compound containing an alkali metal, a compound containing an alkaline earth metal, and a compound containing a rare earth metal.

[0035] According to the embodiments of the present invention, in step (1) or (3), the conditions of the calcination treatment are the same or different, and independently include: at a heating rate of 2-5 °C / min -1 and calcining at 500-800 °C for 2-10 h.

[0036] According to the embodiments of the present invention, in step (3), the calcination treatment is carried out in an inert atmosphere, such as in a N2 atmosphere.

[0037] According to the embodiments of the present invention, in step (3), the conditions of the reduction treatment include at a heating rate of 2-5 °C / min -1 and reducing at a temperature not higher than 500 °C for 2-6 h in a reducing atmosphere.

[0038] According to an embodiment of the present invention, in step (3), the reducing atmosphere is, for example, 10H2 / Ar.

[0039] The present invention also provides the application of the above-mentioned shaped catalyst in the preparation of green ammonia synthesis.

[0040] The present invention also provides a preparation method for green ammonia synthesis, and the preparation method uses the above-mentioned shaped catalyst.

[0041] In the present invention, green ammonia synthesis refers to the electrolysis of water to prepare green hydrogen through renewable energy, and then the synthesis of ammonia with nitrogen.

[0042] Advantages of the present invention:

[0043] 1. The present invention prepares a nano-scale Ru-based ammonia synthesis catalyst through a simple heat treatment method. This method is simple to operate and has a low cost, providing a preparation method for the preparation of nano-scale catalysts.

[0044] 2. The present invention prepares spherical, clover-shaped, and cylindrical activated carbon carriers modified with carbon ash through an extrusion molding method and an extrusion-spheronization molding method, and loads active metals and promoter metals through an incipient wetness impregnation method to prepare a K-Ba-Ru / xC 60 -AC (x = 2-8Wt.%) catalyst, providing an idea for the forming preparation of industrial ammonia synthesis catalysts.

[0045] 3. The forming process of the present invention is simple, easy to operate, has a high output, and a low cost. The forming method is simple and has obvious prospects for industrial application. Description of the Drawings

[0046] Figure 1 For the different particle model diagrams of the three prepared shaped K-Ba-Ru / xC 60 -AC (x = 2-8wt.%) catalysts.

[0047] Figure 2 For the comparison diagrams of the mechanical strength and abrasion rate of different particles of the three prepared shaped K-Ba-Ru / xC 60 -AC (x = 2-8wt.%) catalysts. Detailed Embodiments

[0048] The technical solutions of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are only for illustrative and explanatory purposes of the present invention and should not be construed as limiting the protection scope of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0049] Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available products or can be prepared by known methods.

[0050] Preparation Example 1

[0051] Activated carbon (AC) carriers modified with carbon ash were prepared separately as follows:

[0052] a. Molding of cylindrical activated carbon carriers (2C 60 -AC) modified with 2 wt.% carbon ash:

[0053] Step A: Weigh 500 g of AC powder with a particle size of 200 - 500 mesh (purchased from Fujian Xinsen Carbon Co., Ltd.), 10 g of carbon ash, 50 g of carboxymethyl cellulose, 10 g of high-temperature graphite binder, etc., mix them evenly, then add 10 g of sodium silicate and 300 - 400 mL of deionized water, and further mix and knead evenly;

[0054] Step B: Place the sample kneaded evenly in Step A into an extrusion molding machine for molding. Then, place the carbon ash-promoted cylindrical activated carbon carrier under an infrared lamp for drying, and then transfer the dried cylindrical carrier to a drying oven at 120 °C for further drying for 12 h;

[0055] Step C: Transfer the sample dried in Step B to a tube furnace containing a N2 atmosphere, and calcine it at 500 °C for 4 h at a heating rate of 3 °C / min; -1 After it cools to room temperature, name it the cylindrical activated carbon carrier 2C 60 -AC modified with carbon ash;

[0056] b. Molding of cylindrical activated carbon carriers (4C 60 -AC) modified with 4 wt.% carbon ash:

[0057] Step A: Weigh 500 g of AC powder with a particle size of 200 - 500 mesh, 20 g of carbon ash, 50 g of carboxymethyl cellulose, 10 g of high-temperature graphite binder, etc., mix them evenly, then add 10 g of sodium silicate and 300 - 400 mL of deionized water, and further mix and knead evenly;

[0058] Step B: Place the sample kneaded evenly in Step A into an extrusion molding machine for molding. Then, place the carbon ash-promoted cylindrical activated carbon carrier under an infrared lamp for drying, and then transfer the dried cylindrical carrier to a drying oven at 120 °C for further drying for 12 h;

[0059] Step C: Transfer the sample dried in Step B to a tube furnace containing a N2 atmosphere, and calcine it at 500 °C for 4 h at a heating rate of 3 °C / min; -1 After it cools to room temperature, name it the cylindrical activated carbon carrier (4C 60 -AC) modified with carbon ash;

[0060] c. Molding of cylindrical activated carbon support modified with 5 wt.% carbon ash (5C 60 -AC):

[0061] Step A: Weigh 500 g of AC powder with a mesh size of 200 - 500, 25 g of carbon ash, 50 g of carboxymethyl cellulose, 10 g of high-temperature graphite binder, etc., mix them evenly, then add 10 g of sodium silicate and 300 - 400 mL of deionized water, and further mix and knead evenly;

[0062] Step B: Place the sample kneaded evenly in Step A into an extrusion molding machine for molding. Then, place the carbon ash-promoted cylindrical activated carbon support under an infrared lamp for drying, and then transfer the dried cylindrical support to a vacuum drying oven at 120 °C for further drying for 12 h;

[0063] Step C: Transfer the sample dried in Step B to a tube furnace containing a N2 atmosphere, and at a heating rate of 3 °C / min -1 , calcine at 500 °C for 4 h; After it cools to room temperature, name it the cylindrical activated carbon support modified with carbon ash (5C 60 -AC);

[0064] d. Molding of cylindrical activated carbon support modified with 6 wt.% carbon ash (6C 60 -AC):

[0065] Step A: Weigh 500 g of AC powder with a mesh size of 200 - 500, 30 g of carbon ash, 50 g of carboxymethyl cellulose, 10 g of high-temperature graphite binder, etc., mix them evenly, then add 10 g of sodium silicate and 300 - 400 mL of deionized water, and further mix and knead evenly;

[0066] Step B: Place the sample kneaded evenly in Step A into an extrusion molding machine for molding. Then, place the carbon ash-promoted cylindrical activated carbon support under an infrared lamp for drying, and then transfer the dried cylindrical support to a drying oven at 120 °C for further drying for 12 h;

[0067] Step C: Transfer the sample dried in Step B to a tube furnace containing a N2 atmosphere, and at a heating rate of 3 °C / min -1 , calcine at 500 °C for 4 h; After it cools to room temperature, name it the cylindrical activated carbon support modified with carbon ash (6C 60 -AC);

[0068] e. Molding of cylindrical activated carbon support modified with 8 wt.% carbon ash (8C 60 -AC):

[0069] Step A: Weigh 500 g of AC powder with a particle size of 200 - 500 mesh, 40 g of carbon ash, 50 g of carboxymethyl cellulose, 10 g of high-temperature graphite binder, etc., mix them evenly, then add 10 g of sodium silicate and 300 - 400 mL of deionized water, and further mix and knead evenly;

[0070] Step B: Place the sample kneaded evenly in Step A into an extrusion molding machine for molding. Then, place the carbon ash-promoted cylindrical activated carbon carrier under an infrared lamp for drying. Next, transfer the dried cylindrical carrier to a drying oven at 120 °C for further drying for 12 h;

[0071] Step C: Transfer the sample dried in Step B to a tubular furnace containing an N2 atmosphere, and at a heating rate of 3 °C / min, -1 calcine at 500 °C for 4 h; After it cools to room temperature, name it the cylindrical activated carbon carrier modified with carbon ash (8C 60 -AC);

[0072] Preparation Example 2

[0073] Refer to Preparation Example 1 to prepare a spherical activated carbon carrier modified with carbon ash. Its preparation method is basically the same as that of the cylindrical activated carbon carrier in Preparation Example 1, with the only difference being that: the extrusion molding is combined with the rolling and rounding molding method. This preparation example uses a spherical activated carbon carrier modified with 5 wt.% of carbon ash for illustration. Specifically:

[0074] When preparing a spherical activated carbon carrier modified with 5 wt.% of carbon ash (5C 60 -AC), in Step B, on the basis of extrusion molding, combine the preparation method of rolling and rounding molding. The rest is the same as in Preparation Example 1, and a spherical activated carbon carrier 5C 60 -AC modified with carbon ash is obtained.

[0075] Preparation Example 3

[0076] Refer to Preparation Example 1 to prepare a clover-shaped activated carbon carrier modified with carbon ash. Its preparation method is basically the same as that of the cylindrical activated carbon carrier in Preparation Example 1, with the only difference being that: replace the cylindrical mold for extrusion molding with a clover shape. This preparation example uses a clover-shaped activated carbon carrier modified with 5 wt.% of carbon ash for illustration. Specifically:

[0077] When preparing a clover-shaped activated carbon carrier modified with 5 wt.% of carbon ash (5C 60 -AC), in Step B, replace the mold for extrusion molding. The rest is the same as in Preparation Example 1, and a clover-shaped activated carbon carrier 5C 60 -AC modified with carbon ash is obtained.

[0078] Example 1: Preparation of Ba-Ru / 2C 60 -AC catalyst:

[0079] 1) Ru / 2C 60 - Preparation of AC catalyst:

[0080] Step 1: Weigh 100 g of the cylindrical activated carbon support (2C 60 -AC) modified with carbon ash prepared in Preparation Example 1 above, with a particle size of 12 - 16 mesh, measure 8 mL (1 g / mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0081] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon support modified with carbon ash by the method of equal - volume impregnation multiple times, then dry it under an infrared lamp, and then place it in a vacuum drying oven at 120 °C for 12 h and impregnate repeatedly.

[0082] Step 3: Transfer the sample dried in Step 2 to a tubular furnace, and at a heating rate of 2 °C / min -1 , calcine it at 500 °C for 2 h in an N2 atmosphere. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C / min -1 , conduct a reduction treatment at 500 °C for 2 h. After cooling to room temperature, name it Ru / 2C 60 -AC catalyst.

[0083] 2) Ba - Ru / 2C 60 - Preparation of AC catalyst:

[0084] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water, and in the same loading manner as the active metal, load Ba(CH3COO)2 onto the above - prepared Ru / 2C 60 -AC catalyst, and at a heating rate of 2 °C / min -1 , calcine it at 500 °C for 2 h in an N2 atmosphere. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C / min -1 , conduct a reduction treatment at 500 °C for 2 h. Finally, name it Ru - Ba / 2C 60 -AC catalyst.

[0085] Example 2: Ba - Ru / 4C 60 - Preparation of AC catalyst:

[0086] 1) Ru / 4C 60 - Preparation of AC catalyst:

[0087] Step 1: Weigh 100 g of the cylindrical activated carbon support (4C60 -AC), measure 8 mL (1 g / mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for later use;

[0088] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto a cylindrical activated carbon carrier modified with carbon ash by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp, and then dry it in a vacuum drying oven at 120 °C for 12 h, and impregnate it repeatedly.

[0089] Step 3: Transfer the sample dried in Step 2 to a tubular furnace and heat it at a heating rate of 2 °C / min. -1 Under a N2 atmosphere, calcine it at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. -1 After cooling to room temperature, name it Ru / 4C 60 -AC catalyst.

[0090] 2) Preparation of Ba-Ru / 4C 60 -AC catalyst:

[0091] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. In the same loading method as the active metal, load Ba(CH3COO)2 onto the above-prepared Ru / 4C 60 -AC catalyst and heat it at a heating rate of 2 °C / min. -1 Under a N2 atmosphere, calcine it at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. -1 Finally, name it Ru-Ba / 4C 60 -AC catalyst.

[0092] Example 3: Preparation of Ba-Ru / 5C 60 -AC catalyst:

[0093] 1) Preparation of Ru / 5C 60 -AC catalyst:

[0094] Step 1: Weigh 100 g of the bar-shaped activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 1 with a mesh size of 12-16, measure 8 mL (1 g / mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for later use;

[0095] Step 2: The ruthenium precursor solution prepared in Step 1 was loaded onto a bar-shaped activated carbon support modified with carbon ash by the method of multiple equal-volume impregnation, then dried under an infrared lamp, and then dried in a vacuum drying oven at 120 °C for 12 h, and impregnated repeatedly.

[0096] Step 3: The sample dried in Step 2 was transferred to a tubular furnace and heated at a rate of 2 °C min -1 in an N2 atmosphere and calcined at 500 °C for 2 h. After cooling to room temperature, the calcination atmosphere was switched to 10H2 / Ar, and reduction treatment was carried out at 500 °C for 2 h at a heating rate of 3 °C min -1 . After cooling to room temperature, it was named Ru / 5C 60 -AC catalyst.

[0097] 2) Preparation of Ba-Ru / 5C 60 -AC catalyst:

[0098] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. In the same loading method as the active metal, Ba(CH3COO)2 was loaded onto the above-prepared Ru / 5C 60 -AC catalyst and calcined at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C min -1 . After cooling to room temperature, the calcination atmosphere was switched to 10H2 / Ar, and reduction treatment was carried out at 500 °C for 2 h at a heating rate of 3 °C min -1 . Finally, it was named Ru-Ba / 5C 60 -AC catalyst.

[0099] Example 4: Preparation of Ba-Ru / 6C 60 -AC catalyst:

[0100] 1) Preparation of Ru / 6C 60 -AC catalyst:

[0101] Step 1: Weigh 100 g of the above-prepared cylindrical activated carbon support (6C 60 -AC) with 12-16 mesh, measure 8 mL (1 g mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0102] Step 2: The ruthenium precursor solution prepared in Step 1 was loaded onto the cylindrical activated carbon support modified with carbon ash by the method of multiple equal-volume impregnation, then dried under an infrared lamp, and then dried in a vacuum drying oven at 120 °C for 12 h, and impregnated repeatedly.

[0103] Step 3: Transfer the sample dried in Step 2 to a tubular furnace and calcine it at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C / min. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. After cooling to room temperature, name it Ru / 6C -1 -AC catalyst. -1 Step 1: Weigh 100 g of the cylindrical activated carbon support (8C 60 -AC) modified with carbon ash prepared in Preparation Example 1 with a mesh size of 12 - 16, measure 8 mL (1 g / mL

[0104] ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby; 60 2) Preparation of Ba-Ru / 6C

[0105] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as the active metal, load Ba(CH3COO)2 onto the Ru / 6C 60 -AC catalyst prepared above and calcine it at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C / min. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. Finally, name it Ru-Ba / 6C -1 -AC catalyst. -1 Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon support modified with carbon ash by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp and then dry it in a vacuum drying oven at 120 °C for 12 h, and impregnate it repeatedly. 60

[0106] Example 5: Preparation of Ba-Ru / 8C 60 -AC catalyst:

[0107] 1) Preparation of Ru / 8C 60 -AC catalyst:

[0108] Step 3: Transfer the sample dried in Step 2 to a tubular furnace and calcine it at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C / min. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. 60 -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby; -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0109] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon support modified with carbon ash by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp and then dry it in a vacuum drying oven at 120 °C for 12 h, and impregnate it repeatedly.

[0110] Step 3: Transfer the sample dried in Step 2 to a tubular furnace and calcine it at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C / min. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h at a heating rate of 3 °C / min. -1 After cooling to room temperature, name it Ru / 8C -1The heating rate was 500 °C for 2 h under reduction treatment. After cooling to room temperature, it was named Ru / 8C 60 -AC catalyst.

[0111] 2) Preparation of Ba-Ru / 8C 60 -AC catalyst:

[0112] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as the active metal, load Ba(CH3COO)2 onto the above-prepared Ru / 8C 60 -AC catalyst, and at a heating rate of 2 °C min -1 Under N2 atmosphere, calcine at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C min -1 Reduce at 500 °C for 2 h. Finally, name it Ru-Ba / 8C 60 -AC catalyst.

[0113] Comparative Example 1: Preparation of Ba-Ru / AC catalyst:

[0114] Step 1: Weigh 100 g of a cylindrical activated carbon carrier (AC) with a particle size of 12-16 mesh, measure 8 mL (1 g mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0115] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon carrier by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp, and then place it in a vacuum drying oven at 120 °C for 12 h, and impregnate repeatedly.

[0116] Step 3: Transfer the sample dried in Step 2 to a tube furnace, and at a heating rate of 2 °C min -1 Under N2 atmosphere, calcine at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C min -1 Reduce at 500 °C for 2 h. After cooling to room temperature, name it Ru / AC catalyst.

[0117] 3) Preparation of Ba-Ru / AC catalyst:

[0118] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as the active metal, load Ba(CH3COO)2 onto the above-prepared Ru / 8C 60 -AC catalyst, and at a heating rate of 2 °C min -1The heating rate was maintained at 3 °C min⁻¹, and the sample was calcined at 500 °C for 2 h in an N₂ atmosphere. After cooling to room temperature, the calcination atmosphere was switched to 10% H₂ / Ar, and the sample was reduced at 500 °C for 2 h at a heating rate of 3 °C min⁻¹. Finally, it was named the Ru-Ba / AC catalyst. -1 The cylindrical activated carbon 5C-AC was preferably used to support the active metal and metal promoter:

[0119] Example 6: 4K-Ba-Ru / 5C-AC catalyst preparation: 60 1) Preparation of Ru / 5C-AC catalyst:

[0120] Step 1: Weigh 100 g of the cylindrical activated carbon support (5C-AC) modified with carbon ash prepared in Preparation Example 1, with a particle size of 12-16 mesh, and measure 8 mL of ruthenium nitrate solution (1 g mL⁻¹) and add an appropriate amount of deionized water for later use. 60 Step 2: The ruthenium precursor solution prepared in Step 1 was loaded onto the cylindrical activated carbon support modified with carbon ash by the method of equal-volume impregnation multiple times. Then it was dried under an infrared lamp and then placed in a vacuum drying oven at 120 °C for 12 h, and the impregnation process was repeated several times.

[0121] Step 3: The dried sample from Step 2 was transferred to a tube furnace and calcined at 500 °C for 2 h in an N₂ atmosphere at a heating rate of 2 °C min⁻¹. After cooling to room temperature, the calcination atmosphere was switched to 10% H₂ / Ar, and the sample was reduced at 500 °C for 2 h at a heating rate of 3 °C min⁻¹. After cooling to room temperature, it was named the Ru / 5C-AC catalyst. 60 2) Preparation of Ba-Ru / 5C-AC catalyst:

[0122] Weigh 15.23 g of barium acetate (Ba(CH₃COO)₂) and an appropriate amount of deionized water. Using the same loading method as for the active metal, Ba(CH₃COO)₂ was loaded onto the Ru / 5C-AC catalyst prepared above, and it was calcined at 500 °C for 2 h in an N₂ atmosphere at a heating rate of 2 °C min⁻¹. After cooling to room temperature, the calcination atmosphere was switched to 10% H₂ / Ar, and the sample was reduced at 500 °C for 2 h at a heating rate of 3 °C min⁻¹. 60 The heating rate was maintained at 3 °C min⁻¹, and the sample was calcined at 500 °C for 2 h in an N₂ atmosphere. After cooling to room temperature, the calcination atmosphere was switched to 10% H₂ / Ar, and the sample was reduced at 500 °C for 2 h at a heating rate of 3 °C min⁻¹. After cooling to room temperature, it was named the Ba-Ru / 5C-AC catalyst. -1

[0123]

[0124] -1 -1 60

[0125] 60

[0126] 60 -1 -1The heating rate was [X] °C / min, and it was reduced at 500 °C for 2 h. Finally, it was named Ru-Ba / 5C 60 -AC catalyst.

[0127] 3) 4K-Ba-Ru / 5C 60 Preparation of -AC catalyst:

[0128] Weigh 10.34 g of potassium nitrate (KNO3) and an appropriate amount of deionized water. Using the same loading method as the active metal, load KNO3 onto the above-prepared Ba-Ru / 5C 60 -AC catalyst. Finally, it was named 4K-Ru-Ba / 5C 60 -AC catalyst.

[0129] Example 7: 8K-Ba-Ru / 5C 60 Preparation of -AC catalyst:

[0130] 1) Ru / 5C 60 Preparation of -AC catalyst:

[0131] Step 1: Weigh 100 g of the cylindrical activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 1 with a particle size of 12-16 mesh. Measure 8 mL (1 g / mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0132] Step 2: The ruthenium precursor solution prepared in Step 1 was loaded onto the cylindrical activated carbon carrier modified with carbon ash by the method of equal-volume impregnation multiple times. Then it was dried under an infrared lamp, and then placed in a vacuum drying oven at 120 °C for 12 h and impregnated repeatedly.

[0133] Step 3: The sample dried in Step 2 was transferred to a tubular furnace and calcined at 500 °C for 2 h in an N2 atmosphere at a heating rate of 2 °C / min -1 . After cooling to room temperature, the calcination atmosphere was switched to 10H2 / Ar, and it was reduced at 500 °C for 2 h at a heating rate of 3 °C / min -1 . After cooling to room temperature, it was named Ru / 5C 60 -AC catalyst.

[0134] 2) Ba-Ru / 5C 60 Preparation of -AC catalyst:

[0135] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as the active metal, load Ba(CH3COO)2 onto the above-prepared Ru / 5C 60- on the AC catalyst, and at a heating rate of 2 °C min -1 , in an N2 atmosphere, calcine at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C min -1 , perform reduction treatment at 500 °C for 2 h. Finally, name it Ru-Ba / 5C 60 -AC catalyst.

[0136] 3) Preparation of 8K-Ba-Ru / 5C 60 -AC catalyst:

[0137] Weigh 20.68 g of potassium nitrate (KNO3) and an appropriate amount of deionized water. Using the same loading method as the active metal, load KNO3 onto the above-prepared Ba-Ru / 5C 60 -AC catalyst. Finally, name it 8K-Ru-Ba / 5C 60 -AC catalyst.

[0138] Example 8: Preparation of 12K-Ba-Ru / 5C 60 -AC catalyst:

[0139] 1) Preparation of Ru / 5C 60 -AC catalyst:

[0140] Step A: Weigh 100 g of the cylindrical activated carbon support (5C 60 -AC) modified with carbon ash prepared in Preparation Example 1 with a particle size of 12 - 16 mesh. Measure 8 mL (1 g mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for standby;

[0141] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon support modified with carbon ash by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp, and then place it in a vacuum drying oven at 120 °C for 12 h, and impregnate repeatedly.

[0142] Step 3: Transfer the sample dried in Step 2 to a tubular furnace, and at a heating rate of 2 °C min -1 , in an N2 atmosphere, calcine at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C min -1 , perform reduction treatment at 500 °C for 2 h. After cooling to room temperature, name it Ru / 5C 60 -AC catalyst.

[0143] 2) Preparation of Ba-Ru / 5C 60 -AC catalyst:

[0144] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as for the active metal, load Ba(CH3COO)2 onto the Ru / 5C 60 -AC catalyst prepared above, and with a heating rate of 2 °C min -1 , calcine it at 500 °C for 2 h under a N2 atmosphere. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h with a heating rate of 3 °C min -1 . Finally, name it the Ru-Ba / 5C 60 -AC catalyst.

[0145] 3) Preparation of the 12K-Ba-Ru / 5C 60 -AC catalyst:

[0146] Weigh 31.02 g of potassium nitrate (KNO3) and an appropriate amount of deionized water. Using the same loading method as for the active metal, load KNO3 onto the Ba-Ru / 5C 60 -AC catalyst prepared above. Finally, name it the 12K-Ru-Ba / 5C 60 -AC catalyst.

[0147] Example 9: Preparation of the 16K-Ba-Ru / 5C 60 -AC catalyst:

[0148] 1) Preparation of the Ru / 5C 60 -AC catalyst:

[0149] Step A: Weigh 100 g of the cylindrical activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 1 above, with a particle size of 12 - 16 mesh. Measure 8 mL (1 g mL -1 ) of ruthenium nitrate solution and add an appropriate amount of deionized water for later use;

[0150] Step 2: Load the ruthenium precursor solution prepared in Step 1 onto the cylindrical activated carbon carrier modified with carbon ash by the method of equal-volume impregnation multiple times. Then dry it under an infrared lamp, and then place it in a vacuum drying oven at 120 °C for 12 h, and impregnate it repeatedly.

[0151] Step 3: Transfer the sample dried in Step 2 to a tube furnace and calcine it at 500 °C for 2 h under a N2 atmosphere with a heating rate of 2 °C min -1 . After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar and reduce it at 500 °C for 2 h with a heating rate of 3 °C min -1 . After cooling to room temperature, name it Ru / 5C 60-AC catalyst.

[0152] 2) Ba-Ru / 5C 60 Preparation of -AC catalyst:

[0153] Weigh 15.23 g of barium acetate (Ba(CH3COO)2) and an appropriate amount of deionized water. Using the same loading method as the active metal, load Ba(CH3COO)2 onto the Ru / 5C 60 -AC catalyst prepared above, and at a heating rate of 2 °C / min -1 Under a N2 atmosphere, calcine at 500 °C for 2 h. After cooling to room temperature, switch the calcination atmosphere to 10H2 / Ar, and at a heating rate of 3 °C / min -1 Reduce at 500 °C for 2 h. Finally, name it Ru-Ba / 5C 60 -AC catalyst.

[0154] 3) 16K-Ba-Ru / 5C 60 Preparation of -AC catalyst:

[0155] Weigh 40.36 g of potassium nitrate (KNO3) and an appropriate amount of deionized water. Using the same loading method as the active metal, load KNO3 onto the Ba-Ru / 5C 60 -AC catalyst prepared above. Finally, name it 16K-Ru-Ba / 5C 60 -AC catalyst.

[0156] The carriers used in Examples 1-9 and Comparative Example 1 above are all cylindrical, so the catalysts are also all cylindrical catalysts.

[0157] Example 10

[0158] Refer to Example 3 to prepare a spherical Ba-Ru / 5C60-AC catalyst, with the only difference being: replace the cylindrical activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 10 with the spherical activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 3 to obtain a spherical Ba-Ru / 5C60-AC catalyst.

[0159] Example 11

[0160] Refer to Example 3 to prepare a spherical Ba-Ru / 5C60-AC catalyst, with the only difference being: replace the cylindrical activated carbon carrier (5C 60 -AC) modified with carbon ash prepared in Preparation Example 11 with the clover-shaped activated carbon carrier (5C 60-(AC), a clover-shaped Ba-Ru / 5C60-AC catalyst was obtained.

[0161] Test Example 1

[0162] Certain amounts of the catalysts of Example 3, Example 10, and Example 11 were taken respectively to test the mechanical strength (the test method refers to GB / T 7702.3-2008, the sample amount is 1 g, and no steel balls are placed during the test) and the attrition rate (the test method refers to GB / T30202.3-2013, and the running time during the attrition rate test is 20 min). The specific results are as follows:

[0163] From Figure 1 It can be seen that the particle models of the catalysts are cylindrical (the catalyst of Example 1), spherical (the catalyst of Example 10), and clover-shaped (the catalyst of Example 11) respectively.

[0164] From Figure 2 It can be seen that the average mechanical strengths of the catalysts of Example 3, Example 10, and Example 11 are 280.5, 280.1, and 314.7 N cm -1 , and the average attrition rates are 0.1, 0, and 0.1% respectively. It can be seen that the above three-shaped catalysts of the present invention all have high mechanical strength and small attrition rate, and all meet the industrial requirements.

[0165] Application Example 1

[0166] Catalyst performance evaluation

[0167] 2 mL of the catalysts of Examples 1-11 were respectively used, and the mass space velocity was 60,000 mL g -1 h -1 , and ammonia synthesis was determined on a fixed-bed ammonia synthesis catalyst activity test device. The volume fraction of ammonia (NH3%) in the outlet gas was determined by the sulfuric acid neutralization method, and the reaction gas composition was: 25% N2 + 75% H2. The temperature was at 375 and 400 °C, and the pressure was at 5 and 10 MPa. The catalytic performance of the catalyst was determined, and the test results are shown in Table 1.

[0168] Table 1 Ammonia synthesis catalytic performance of different catalysts

[0169]

[0170]

[0171] It can be found from Examples 1-5 and Comparative Example 1 in Table 1 that the Ru-Ba / 5C 60 -AC catalyst has the optimal catalytic activity, which is about 1.4 times that of the carbon ash Ru-Ba / AC catalyst. Therefore, the inventor used Ru-Ba / 5C60 - Based on the AC catalyst, the catalysts of Examples 6 - 9 were prepared by further loading the alkali metal promoter potassium. It can be found from Examples 6 - 9 in Table 1 that they have high catalytic activity at relatively low pressures and temperatures. Among them, 12K-Ru-Ba / 5C 60 - AC can reach an ammonia concentration of 11.39% at 375 °C and 5 MPa.

[0172] When the shaped catalysts of Examples 9 and 10 were used to synthesize ammonia by the method of Application Example 3, the ammonia concentrations were also greater than 10%, and the catalytic efficiency of ammonia production was basically the same as that of Example 3. It can be seen that the shape of the shaped catalyst of the present invention does not affect its catalytic efficiency.

[0173] The above has described the exemplary embodiments of the present invention. However, the protection scope of this application is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A shaped activated carbon carrier, characterized in that: The raw materials of the shaped activated carbon carrier include a carbon source, carbon ash and a binder; The carbon source is selected from at least one of powdered activated carbon AC and carrier NC; The carbon ash includes C 60 and / or C 70 ; The adhesive is selected from at least one or more of starch, high temperature graphite adhesive, sesbania powder, activated carbon, glycerol, oxalic acid, citric acid, silica sol, aluminum sol, nitric acid, polyethylene glycol, polyvinyl alcohol, cellulose, formic acid, acetic acid, and hydrochloric acid.

2. The shaped activated carbon carrier according to claim 1, characterized in that The carbon ash accounts for 2-8wt.% of the mass of the carbon source; and / or, the binder accounts for 2-8 wt.% of the mass of the carbon source; And / or, the shaped activated carbon carrier is selected from at least one of a cylindrical, a clover-shaped and a spherical shape.

3. The molding process of the molded activated carbon carrier according to claim 1 or 2, characterized in that: The molding process comprises: mixing a carbon source, carbon ash and a binder, kneading them, molding them, and then drying and sintering them to obtain the molded activated carbon carrier.

4. The molding process according to claim 3, characterized in that: The drying treatment is specifically drying at 80-150° C. for 12-24 hours; And / or, the sintering treatment includes sintering in a N2 atmosphere for 2-12 hours; the sintering temperature is 400-900°C.

5. A shaped catalyst, characterized in that: The shaped catalyst comprises: the shaped activated carbon carrier according to claim 1 or 2, the active metal Ru and an auxiliary agent.

6. The shaped catalyst according to claim 5, characterized in that In the molded catalyst, the mass of Ru accounts for 1-10wt.% of the total mass of the molded activated carbon carrier; And / or, the auxiliary agent is selected from at least one of alkali metals, alkaline earth metals and rare earth metals; And / or, the content of the auxiliary agent accounts for 0-20wt.% of the total mass of the shaped activated carbon carrier; And / or, in the molded catalyst, the alkali metal is selected from at least one of Na, K and Cs; And / or, in the shaped catalyst, the alkaline earth metal is selected from at least one of Mg, Ca and Ba; And / or, in the shaped catalyst, the rare earth metal is selected from at least one of La, Ce and Sm.

7. The method for preparing a shaped catalyst according to claim 5 or 6, characterized in that: The preparation method comprises: (1) Preparing a shaped activated carbon carrier loaded with active metal Ru: mixing the shaped activated carbon carrier and a compound containing active metal (Ru), and then drying; after drying, calcining and reducing treatment are optionally performed; (2) preparing a shaped activated carbon carrier loaded with active metal Ru and an additive: mixing a compound containing an additive with the shaped activated carbon carrier loaded with active metal Ru in step (1), and drying the mixture; (3) The shaped activated carbon carrier loaded with active metal Ru and auxiliary agents in step (2) is subjected to calcination treatment and reduction treatment in sequence to obtain the shaped catalyst.

8. The preparation method according to claim 7, characterized in that: In step (2), the auxiliary agent-containing compound is selected from at least one of an alkali metal-containing compound, an alkaline earth metal-containing compound and a rare earth metal-containing compound; And / or, in step (1) or (3), the calcination conditions are the same or different and independently include: -1 Heating rate: calcination at 500-800℃ for 2-10h; And / or, in step (3), the calcination treatment is carried out under an inert atmosphere; And / or, in step (3), the reduction treatment conditions include 2-5°C min -1 The heating rate is in a reducing atmosphere and the reduction is carried out at a temperature not exceeding 500°C for 2-6 hours.

9. Use of the shaped catalyst according to claim 5 or 6 in the preparation of green ammonia.

10. A method for preparing green ammonia, characterized in that: The preparation method adopts the shaped catalyst described in claim 5 or 6.

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