Preparation device and preparation method of catalyst for catalytic oxidation of methanol and hydrogen

Abstract

The invention provides a preparation device and a preparation method of a catalyst for catalytic oxidation of methanol and hydrogen. The preparation method comprises the following steps: step 1, preparation of a cerium-aluminum composite oxide: calculating corresponding Ce according to a proportion, dissolving the Ce in water, adding corresponding Al2O3, stirring for 2-6 hours, adding a precipitator, and putting the mixture into a barrel for filtering and cleaning; then, the precipitate is dried and calcined, and a carrier Ce-Al2O3 is obtained; and 2, mixing the Pt-containing solution with a corresponding auxiliary agent X solution, loading the mixture on a cerium-aluminum composite oxide Ce-Al2O3, carrying out ion exchange for 12-24 hours, and drying at 80-120 DEG C to obtain a finished product catalyst, the preparation device and the preparation method of the catalyst for catalytic oxidation of methanol and hydrogen provided by the invention have the advantages that the production efficiency of the catalyst is improved, and the preparation method which is simple, easy to operate and suitable for large-scale production and the application of the preparation method are provided.

Description

Technical Field

[0001] The present invention relates to the technical field of catalyst preparation, and particularly to a preparation device and a preparation method of a catalyst for catalytic oxidation of methanol and hydrogen. Background Art

[0002] With the development of the times, people pay more and more attention to the concept of low-carbon environmental protection and have higher and higher requirements for the environment and quality of life. At the same time, the country has also put forward new goals for the development of new energy and environmental protection. In particular, the use of fossil energy has caused a large amount of pollution. Therefore, the use of clean energy has received extensive attention. Among them, hydrogen fuel cells and their hydrogen supply systems have become the focus of attention, but the source of hydrogen has become one of the difficulties. Compared with high-pressure hydrogen storage, methanol is an excellent liquid hydrogen storage and transportation carrier with good application prospects. The methanol reforming hydrogen production system mainly includes raw material vaporization, methanol reforming, gas purification and catalytic combustion, etc. The role of the catalytic combustion part is to oxidize methanol and combustible gases in the fuel cell tail gas.

[0003] The methanol reforming hydrogen production system mainly includes raw material vaporization, methanol reforming, gas purification, etc. Among them, a large amount of heat is required for raw material vaporization, and the methanol reforming reaction is an endothermic reaction, consuming a large amount of heat during the reaction. Currently, most methanol hydrogen production systems on the market use natural gas heating, electric heating and other methods, which are complex in process, high in energy consumption and poor in environmental protection. To solve this situation, some researchers have developed methanol catalytic combustion catalysts, using the heat released by methanol oxidation to provide energy for methanol vaporization and reforming. Among them, platinum and palladium noble metal catalysts have excellent activity and longer service life compared with traditional catalysts. The catalysts prepared according to the documents [A catalyst for rapid combustion of methanol at room temperature - An Baoli, Study on the synthesis of Al2O3 supported Pt catalyst and its performance for low-temperature catalytic combustion of methanol - Zhu Miao] still have problems such as high noble metal loading, uneven distribution, poor low-temperature activity, and cumbersome steps; according to the patent document [A low-temperature catalyst for catalytic oxidation of methanol and its preparation method] (CN: 112007682), the prepared catalyst needs to be calcined at high temperature multiple times, resulting in agglomeration of noble metal particles and uneven loading. Traditional methods need to use reducing agents / precipitating agents, such as sodium tantalate, ammonia water, etc., generating a large amount of waste gas and waste water, which does not conform to the trend of green chemistry; and existing catalysts such as Pt / Al2O3 have problems such as low methanol conversion rate at low temperatures.

[0004] Therefore, it is necessary to provide a new preparation device and a preparation method of a catalyst for catalytic oxidation of methanol and hydrogen to solve the above technical problems. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a preparation device and a preparation method for a catalyst used for catalytic oxidation of methanol and hydrogen, which can improve the production efficiency of the catalyst and ensure that the prepared catalyst has uniform distribution and good activity.

[0006] To solve the above technical problem, the preparation device for the catalyst used for catalytic oxidation of methanol and hydrogen provided by the present invention includes: a cylinder body, a compression mechanism for adjusting the internal pressure of the cylinder body is installed at the top of the cylinder body, and a filtering mechanism for filtering precipitates is installed at the bottom of the cylinder body, and a flushing mechanism for cleaning the precipitates is installed inside the cylinder body; an adjusting mechanism for improving the cleaning efficiency of the precipitates is installed inside the cylinder body. The adjusting mechanism includes a discharge pipe, the discharge pipe is installed at the bottom of the cylinder body, a backflush pipe is obliquely installed on the side wall of the discharge pipe, and the discharge pipe is threadedly connected with an adjusting rod; a support column is installed inside the filtering mechanism, a fixing block is installed inside the support column, and the discharge pipe is clamped inside the fixing block; the top end of the adjusting rod is fixedly connected with a first piston with an arc-shaped bottom side wall, and the first piston is slidably connected inside the fixing block; a second piston is installed at the top end of the first piston, a rubber pad with a frustum-shaped surface is installed on the side wall of the second piston, and the rubber pad abuts against the surface of the fixing block. The diameter of the first piston is equal to the inner diameter of the fixing block, and the inner diameter of the fixing block is greater than the diameter of the second piston.

[0007] Preferably, a feed pipe is installed at the top of the cylinder body, and a sewage discharge pipe is installed at the bottom of the cylinder body with a funnel-shaped bottom end.

[0008] Preferably, the compression mechanism includes a hydraulic rod, the hydraulic rod is installed on the surface of the cylinder body, a compression plate is slidably connected inside the cylinder body, and the surface of the compression plate is connected with the hydraulic rod; connecting pipes are installed at both ends of the cylinder body, and both ends of the communicating pipe are respectively connected with the connecting pipes.

[0009] Preferably, the filtering mechanism includes a support ring, the support ring is fixedly connected inside the cylinder body, and a clamping ring is clamped inside the support ring; the cylinder body is threadedly connected with a plurality of screw rods, and the screw rods abut against the surface of the clamping ring.

[0010] Preferably, the filtering mechanism further includes a support net, the support net is installed inside the clamping ring through a plurality of bolts, a plurality of pressing rods are fixedly connected inside the clamping ring, a filter membrane is laid between the pressing rods and the support net; one end of the pressing rod is fixedly connected with the support column, and the support column penetrates through the filter membrane and the support net.

[0011] Preferably, the flushing mechanism includes a flushing pipe. A plurality of annular flushing pipes are installed at the bottom end of the cylinder body. The side wall of the flushing pipe communicates with a water inlet pipe and one of the connecting pipes. The flushing pipes are communicated with each other through support rods. A plurality of spray heads are installed on the side wall of each flushing pipe.

[0012] Preferably, the spray heads are inclined on the surface of the flushing pipe, and the orientation of the spray heads gradually becomes vertical along the direction from the center of the cylinder body towards the edge of the cylinder body.

[0013] Preferably, the top end of the discharge pipe is funnel-shaped, and a gasket is provided between the discharge pipe and the support column.

[0014] Preferably, valves are installed on the side walls of the feed pipe, the sewage discharge pipe, the connecting pipe, the communicating pipe, the discharge pipe, the backwashing pipe, and the water inlet pipe.

[0015] A preparation method for a catalyst for catalytic oxidation of methanol and hydrogen specifically includes the following steps:

[0016] Step 1: Prepare the carrier Ce-Al2O3: Disperse Al2O3 powder and cerium nitrate in deionized water, and ultrasonicate for 30 min. The mass ratio of Al2O3 to cerium nitrate is 8:5, and 40 mL of deionized water is used for every 1 g of cerium nitrate. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH value to 8, and then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, and then pour the solution into the interior of the cylinder body. The filtering mechanism inside the cylinder body separates the precipitate from the liquid. At the same time, the compression mechanism operates to increase the pressure inside the cylinder body and accelerate the filtering efficiency. After filtering, make the water spray out through the flushing mechanism and the adjusting mechanism. The adjusting mechanism makes the water drive the precipitate on the surface of the filtering mechanism towards the outside of the cylinder body. The flushing mechanism drives the water to backwash the filtering mechanism obliquely upwards, making the precipitate constantly turn upwards. And the compression mechanism operates to drive the precipitate to constantly turn in the cleaning solution, accelerating the cleaning efficiency. The cleaned precipitate is dried at 120 °C for 12 h and calcined in a muffle furnace at 400 - 600 °C for 2 h to obtain the carrier Ce-Al2O3.

[0017] Step 2: Mix the platinum nitrate solution and the corresponding additive X solution, and disperse them in deionized water to obtain a noble metal solution. The X solution is one or a combination of solutions containing Co, Fe, Mn, Ni, Cu, and Zn elements. The mass ratio of Pt to additive X is 1:0 to 1:20, and 500 mL of deionized water is used per 1 g of Pt. Ultrasonic the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 80 - 100 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonic for 30 min to obtain a carrier solution, and 20 mL of deionized water is used per 1 g of Ce-Al2O3. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, then quickly filter it into the interior of the cylinder to obtain a precipitate. Wash the precipitate clean inside the cylinder, and dry the washed precipitate at 80 - 120 °C to obtain the finished catalyst.

[0018] Compared with the related technology, the preparation device and preparation method of the catalyst for catalytic oxidation of methanol and hydrogen provided by the present invention have the following beneficial effects:

[0019] First, the present invention uses a composite oxide of active nano-Al2O3 and CeO2 as the base powder, retaining its characteristics of porous and large specific surface area, which is beneficial to the uniform loading of noble metal Pt, greatly improving the utilization rate of noble metal, and thus achieving the problem of reducing the usage amount of noble metal. Second, a large amount of CeO2 is introduced into the catalyst. The conversion between Ce3+ and Ce4+ greatly improves the oxygen storage capacity, provides more active oxygen for the catalyst, and can assist methanol to achieve stable low-temperature catalytic combustion. Third, the addition of additive X (additive X is one or a combination of Co, Fe, Mn, Ni, Cu, and Zn) increases the uniform loading of Pt to a certain extent, and at the same time weakens the adsorption of a small amount of CO in the fuel cell tail gas on Pt, which can improve the low-temperature combustion effect of H2. At the same time, additive X is a transition metal with diverse valence states, which can also provide active oxygen for the reaction and reduce the usage amount of noble metal to a certain extent.

[0020] Fourth, during the production process of the catalyst, when it is necessary to filter and wash the precipitate, the solution-mixed precipitate enters the interior of the cylinder. The filtering mechanism inside the cylinder separates the precipitate from the liquid. At the same time, the compression mechanism operates to increase the pressure inside the cylinder, accelerating the filtering efficiency. After filtering, water is sprayed through the flushing mechanism and the regulating mechanism. The regulating mechanism makes the water drive the precipitate on the surface of the filtering mechanism to move towards the outside of the cylinder. At the same time, the flushing mechanism drives the water to reverse-flush the filtering mechanism obliquely upwards, making the precipitate continuously turn upwards. And the compression mechanism operates to drive the precipitate to continuously turn in the cleaning solution, accelerating the cleaning efficiency of the precipitate and facilitating the next-step processing of the precipitate.

[0021] Fifthly, the catalyst prepared according to the present invention adopts an ion exchange technology. Without introducing a reducing agent or a precipitating agent, the active component (such as Pt) is tightly combined with the cerium-aluminum composite oxide (Ce-Al2O3) through chemical bonds, significantly improving the distribution uniformity of the noble metal and the stability of the catalyst. By adopting the ion exchange technology, complex steps such as multiple impregnations and high-temperature calcination in the traditional impregnation method are avoided, significantly reducing the energy consumption and the emissions of waste gas and waste water during the preparation process, and simplifying the preparation process. Through the chemical bond combination method, the loading amount of the noble metal (such as Pt) is significantly reduced, and at the same time, the distribution is more uniform, improving the low-temperature activity and stability of the catalyst and the utilization rate of the noble metal. The catalyst of the present invention can achieve the efficient catalytic oxidation of methanol and hydrogen at room temperature, significantly reducing the reaction temperature and energy consumption. Moreover, the preparation method provided by the present invention is simple and easy to operate, suitable for large-scale industrial production, and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of a preferred embodiment of the preparation device and the preparation method of the catalyst for catalytic oxidation of methanol and hydrogen provided by the present invention;

[0023] Figure 2 is Figure 1 a side view of the internal structure of the shown cylinder body;

[0024] Figure 3 is Figure 2 an enlarged schematic view of the structure at A shown;

[0025] Figure 4 is Figure 2 an enlarged schematic view of the structure at B shown;

[0026] Figure 5 is Figure 2 an enlarged schematic view of the structure at C shown;

[0027] Figure 6 is Figure 1 a top view of the internal structure of the shown cylinder body;

[0028] Figure 7 is Figure 3 a disassembled schematic view of the snap ring, filter membrane and support net structure shown;

[0029] Figure 8 is Figure 4 a schematic view of the first piston and the fixed block structure shown;

[0030] Figure 9 is a comparison schematic diagram of t 200 and t 400 of the catalyst samples of Examples 1-4 and Comparative Example 1 under Test Condition 1;

[0031] Figure 10 For the catalyst samples of Examples 1-4 and Comparative Example 1 under Test Condition 2, t 200 and t 400 Comparison schematic diagram.

[0032] Reference numerals in the figure: 1, cylinder body; 11, feed pipe; 12, sewage pipe; 2, valve; 3, compression mechanism; 31, hydraulic rod; 32, connecting pipe; 33, communicating pipe; 34, compression plate; 4, adjustment mechanism; 41, discharge pipe; 42, backwash pipe; 43, adjustment rod; 44, gasket; 45, support column; 46, first piston; 47, fixed block; 48, second piston; 49, rubber pad; 5, filtering mechanism; 51, support ring; 52, snap ring; 53, support mesh; 54, filter membrane; 55, pressure rod; 56, bolt; 57, screw rod; 6, flushing mechanism; 61, flushing pipe; 62, spray head; 63, support rod; 64, water inlet pipe. Detailed implementation manners

[0033] The present invention will be further described below in conjunction with the accompanying drawings and implementation manners.

[0034] Please refer to Figures 1 to 8 , Figure 1 which is a schematic structural diagram of a preferred embodiment of the preparation device and preparation method of the catalyst for catalytic oxidation of methanol and hydrogen provided by the present invention; Figure 2 is Figure 1 a side view of the internal structure of the cylinder body shown in Figure 3 is Figure 2 an enlarged schematic diagram of the structure at A shown in Figure 4 is Figure 2 an enlarged schematic diagram of the structure at B shown in Figure 5 is Figure 2 an enlarged schematic diagram of the structure at C shown in Figure 6 is Figure 1 a top view of the internal structure of the cylinder body shown in Figure 7 is Figure 3 an exploded schematic diagram of the structures of the snap ring, filter membrane and support mesh shown in Figure 8 is Figure 4Schematic diagram of the first piston and fixed block shown. The preparation device for the catalyst used to catalytically oxidize methanol and hydrogen includes: a cylinder body 1, a filtering mechanism 5 for filtering precipitates is installed at the bottom end of the cylinder body 1. The filtering mechanism 5 includes a support ring 51, the support ring 51 is fixedly connected inside the cylinder body 1, and a snap ring 52 is engaged inside the support ring 51; the cylinder body 1 is threadedly connected with a plurality of screw rods 57, and the screw rods 57 abut against the surface of the snap ring 52; the filtering mechanism 5 further includes a support net 53, the support net 53 is installed inside the snap ring 52 through a plurality of bolts 56, and a plurality of pressing rods 55 are fixedly connected inside the snap ring 52, and a filter membrane 54 is laid between the pressing rods 55 and the support net 53; one end of the pressing rod 55 is fixedly connected with the support column 45, and the support column 45 penetrates through the filter membrane 54 and the support net 53; when installing the filter membrane 54, first place the filter membrane 54 inside the snap ring 52 to abut against the pressing rods 55, and then fix the support net 53 inside the snap ring 52 through the bolts 56, thereby installing the filter membrane 54 inside the snap ring 52; place the snap ring 52 inside the cylinder body 1 to engage with the support ring 51, and rotate the screw rods 57 to abut against the surface of the snap ring 52, so as to quickly complete the installation of the filter membrane 54 and facilitate the replacement of the filter membrane 54; and when using the filter membrane 54, the pressing rods 55 and the support net 53 clamp the filter membrane 54 to prevent the filter membrane 54 from shifting.

[0035] A feed pipe 11 is installed at the top end of the cylinder body 1, and a sewage discharge pipe 12 is installed at the bottom end of the cylinder body 1 with a funnel-shaped bottom end; a compression mechanism 3 for adjusting the internal pressure of the cylinder body 1 is installed at the top end of the cylinder body 1. The compression mechanism 3 includes a hydraulic rod 31, the hydraulic rod 31 is installed on the surface of the cylinder body 1, a compression plate 34 is slidably connected inside the cylinder body 1, and the surface of the compression plate 34 is connected to the hydraulic rod 31; connection pipes 32 are respectively installed at both ends of the cylinder body 1, and both ends of a communicating pipe 33 are respectively connected to the connection pipes 32. When the precipitate solution enters the inside of the cylinder body 1 through the feed pipe 11, use a valve 2 to close the feed pipe 11; open the connection pipe 32 at the top end of the cylinder body 1 to make the inside of the top end of the cylinder body 1 communicate with the outside through the connection pipe 32, connect the hydraulic rod 31 to the power supply, and open the hydraulic rod 31 to push the compression plate 34 to move downward. The compression plate 34 squeezes the gas and liquid inside the cylinder body 1 to increase the internal pressure of the cylinder body 1, facilitating the solution to penetrate through the filter membrane 54 and enter the bottom end of the cylinder body 1. Open the sewage discharge pipe 12 at regular intervals to discharge the solution, then close the sewage discharge pipe 12 again, and at the same time, the hydraulic rod 31 moves again to push the compression plate 34 downward to maintain the internal pressure of the cylinder body 1 and increase the filtration efficiency.

[0036] An adjusting mechanism 4 for accelerating the cleaning efficiency of sediment is installed inside the cylinder body 1. The adjusting mechanism 4 includes a discharge pipe 41, and the discharge pipe 41 is installed at the bottom end of the cylinder body 1. A backflush pipe 42 is installed obliquely on the side wall of the discharge pipe 41, and the discharge pipe 41 is threadedly connected to an adjusting rod 43; a support column 45 is installed inside the filtering mechanism 5, a fixing block 47 is installed inside the support column 45, and the discharge pipe 41 is clamped inside the fixing block 47; the top end of the adjusting rod 43 is fixedly connected to a first piston 46 with an arc-shaped bottom side wall, and the first piston 46 is slidably connected inside the fixing block 47; a second piston 48 is installed at the top end of the first piston 46, a rubber pad 49 with a frustum-shaped surface is installed on the side wall of the second piston 48, and the rubber pad 49 abuts against the surface of the fixing block 47. The diameter of the first piston 46 is equal to the inner diameter of the fixing block 47, and the inner diameter of the fixing block 47 is greater than the diameter of the second piston 48. When installing the snap ring 52, the snap ring 52 drives the support column 45 to move downward, the discharge pipe 41 enters the inside of the fixing block 47, and the adjusting rod 43 is rotated. The adjusting rod 43 drives the second piston 48 and the rubber pad 49 into the inside of the fixing block 47, and the rubber pad 49 is squeezed inside the fixing block 47. As the second piston 48 slides out of the inside of the fixing block 47, the rubber pad 49 returns to its original frustum-shaped structure after separating from the fixing block 47. The adjusting rod 43 is rotated downward so that the adjusting rod 43 is closely attached to the surface of the fixing block 47, and the first piston 46 is located inside the fixing block 47 to seal it (as shown in the appendix Figure 4 ), to prevent sediment from being discharged from the inside of the fixing block 47.

[0037] The top end of the discharge pipe 41 is funnel-shaped. To facilitate the sediment on the surface of the filter membrane 54 to enter the inside of the discharge pipe 41 through the fixing block 47, a sealing gasket 44 is provided between the discharge pipe 41 and the support column 45 to facilitate increasing the sealing performance between the discharge pipe 41 and the support column 45.

[0038] Inside the cylinder body 1, a flushing mechanism 6 is installed for cleaning the sediment; the flushing mechanism 6 includes a flushing pipe 61. A plurality of annular flushing pipes 61 are installed at the bottom end of the cylinder body 1. A water inlet pipe 64 and one of the connecting pipes 32 are communicated with the side wall of the flushing pipe 61; the flushing pipes 61 are communicated with each other through support rods 63. A plurality of nozzles 62 are installed on the side wall of each flushing pipe 61; the nozzles 62 are inclined on the surface of the flushing pipe 61. When the sediment remains on the surface of the filter membrane 54 and needs to be washed, the reverse flushing pipe 42 and the flushing pipe 61 are connected to a water pump, so that water enters the inside of the reverse flushing pipe 42 and the flushing pipe 61. Rotate the adjusting rod 43 upward to push the first piston 46 upward. The bottom end of the first piston 46 is located at the water outlet of the fixed block 47 (as shown in the attachment Figure 8 ), the bottom end of the first piston 46 is arc-shaped, and the water discharged from the fixed block 47 moves along the side wall of the first piston 46, so that the water moves from the center of the filter membrane 54 to the edge of the filter membrane 54, blowing up the sediment on the surface of the filter membrane 54. At the same time, the water inside the flushing pipe 61 is sprayed obliquely upward through the nozzles 62 to perform reverse flushing on the filter membrane 54, further pushing the sediment upward to make the sediment and water mix evenly; and the orientation of the nozzles 62 gradually becomes vertical along the direction from the center of the cylinder body 1 to the edge of the cylinder body 1. The water sprayed from the nozzles 62 drives the sediment to move towards the inner side wall of the cylinder body 1, thereby further blowing up the sediment and mixing it with water; when the water level reaches the height of the feed pipe 11, turn the adjusting rod 43 to make the first piston 48 close the fixed block 47 and turn off the water pump; open the hydraulic rod 31, and at the same time open the connecting pipe 32 located at the bottom end of the cylinder body 1. The hydraulic rod 31 drives the compression plate 34 to move up and down continuously. When the compression plate 34 moves downward, the compression plate 34 squeezes the water inside the cylinder body 1 downward, and the water enters the bottom end of the cylinder body 1 through the nozzles 62, the flushing pipe 61, the connecting pipe 32, and the communicating pipe 33. When the compression plate 34 moves upward, the compression plate 34 pushes the water at the top end of the cylinder body 1 to be sprayed out through the nozzles 62 again. As the compression plate 34 moves up and down continuously, the sediment and water move continuously to clean the surface of the sediment; after the sediment is cleaned, open the discharge pipe 41, turn the adjusting rod 43 downward to separate the first piston 46 from the fixed block 47, and at the same time connect the water inlet pipe 64 to the water pump to discharge the sediment on the surface of the filter membrane 54 through the discharge pipe 41.

[0039] Valves 2 are installed on the side walls of the feed pipe 11, the sewage discharge pipe 12, the connecting pipe 32, the communicating pipe 33, the discharge pipe 41, the backwashing pipe 42, and the water inlet pipe 61 to control the opening and closing of the pipelines through the valves 2.

[0040] Example 1

[0041] A preparation method of a catalyst for catalytic oxidation of methanol and hydrogen specifically includes the following steps:

[0042] Step 1: Prepare the carrier Ce-Al2O3: Disperse Al2O3 powder and cerium nitrate in deionized water, and ultrasonicate for 30 min. The mass ratio of Al2O3 to cerium nitrate is 8:5, and 40 mL of deionized water is paired with every 1 g of cerium nitrate. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH to 8, and then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, and then pour the solution into the interior of the cylinder 1. The precipitate is quickly filtered and washed inside the cylinder 1. The washed precipitate is dried at 120 °C for 12 h and calcined in a muffle furnace at 600 °C for 2 h. CeO2 is formed from cerium oxalate under high-temperature conditions, and CeO2 and Al2O3 are mixed during the smelting process to obtain the carrier Ce-Al2O3, where Ce accounts for 20 wt%.

[0043] Step 2: Mix platinum nitrate solution and iron nitrate and disperse them in deionized water to obtain a noble metal solution. 14.4 g of iron nitrate powder is paired with every 1 g of Pt, and 500 mL of deionized water is paired with every 1 g of Pt. Ultrasonicate the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 97 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonicate for 30 min to obtain a carrier solution. 20 mL of deionized water is paired with every 1 g of Ce-Al2O3. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, and then quickly filter it into the interior of the cylinder 1 to obtain a precipitate. Wash the precipitate clean inside the cylinder 1. The washed precipitate is dried at 80 - 120 °C to obtain the finished catalyst A. Reduce the catalyst A in an atmosphere of 10% H2 at 400 °C for 2 h.

[0044] Example 2

[0045] A preparation method of a catalyst for catalytic oxidation of methanol and hydrogen specifically includes the following steps:

[0046] Step 1: Prepare the carrier Ce-Al2O3: Disperse Al2O3 powder and cerium nitrate in deionized water, and ultrasonicate for 30 min. The mass ratio of Al2O3 to cerium nitrate is 8:5, and 40 mL of deionized water is added per 1 g of cerium nitrate. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH to 8, then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, and then pour the solution into the interior of the cylinder 1. The precipitate is quickly filtered and washed inside the cylinder 1. The washed precipitate is dried at 120 °C for 12 h and calcined in a muffle furnace at 600 °C for 2 h. Cerium oxalate generates CeO2 under high-temperature conditions, and during the smelting process, CeO2 and Al2O3 are mixed to obtain the carrier Ce-Al2O3, where Ce accounts for 20 wt%.

[0047] Step 2: Mix platinum nitrate solution and iron nitrate and disperse them in deionized water to obtain a noble metal solution. 72 g of iron nitrate powder is added per 1 g of Pt, and 500 mL of deionized water is added per 1 g of Pt. Ultrasonicate the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 97 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonicate for 30 min to obtain a carrier solution. 20 mL of deionized water is added per 1 g of Ce-Al2O3. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, and then quickly filter to obtain a precipitate inside the cylinder 1. Wash the precipitate clean inside the cylinder 1. The washed precipitate is dried at 80 - 120 °C to obtain the finished catalyst B. Reduce the catalyst B in an atmosphere of 10% H2 at 400 °C for 2 h.

[0048] Example 3

[0049] A preparation method of a catalyst for catalytic oxidation of methanol and hydrogen, specifically including the following steps:

[0050] Step 1: Prepare the carrier Ce-Al2O3: Disperse Al2O3 powder and cerium nitrate in deionized water, and ultrasonicate for 30 min. The mass ratio of Al2O3 to cerium nitrate is 8:5, and 40 mL of deionized water is added per 1 g of cerium nitrate. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH to 8, then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, and then pour the solution into the interior of the cylinder 1. The precipitate is quickly filtered and washed inside the cylinder 1. The washed precipitate is dried at 120 °C for 12 h and calcined in a muffle furnace at 600 °C for 2 h. Cerium oxalate generates CeO2 under high-temperature conditions, and during the smelting process, CeO2 and Al2O3 are mixed to obtain the carrier Ce-Al2O3, where Ce accounts for 20 wt%.

[0051] Step 2: Mix the platinum nitrate solution and iron nitrate and disperse them in deionized water to obtain a noble metal solution. For every 1 g of Pt, 28.8 g of iron nitrate powder is used, and for every 1 g of Pt, 1000 mL of deionized water is used. Ultrasonic the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 97 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonic for 30 min to obtain a carrier solution. For every 1 g of Ce-Al2O3, 20 mL of deionized water is used. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, then quickly filter it inside the cylinder 1 to obtain a precipitate. Wash the precipitate clean inside the cylinder 1, and dry the washed precipitate at 80 - 120 °C to obtain the finished catalyst C. Reduce the catalyst C in an atmosphere of 10% H2 at 400 °C for 2 h.

[0052] Example 4

[0053] A preparation method of a catalyst for catalytic oxidation of methanol and hydrogen, specifically including the following steps:

[0054] Step 1: Prepare the carrier Ce-Al2O3: Disperse the Al2O3 powder and cerium nitrate in deionized water, ultrasonic for 30 min, where the mass ratio of Al2O3 to cerium nitrate is 8:5. For every 1 g of cerium nitrate, 40 mL of deionized water is used. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH to 8, then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, then pour the solution into the inside of the cylinder 1, and quickly filter and wash the precipitate inside the cylinder 1. Dry the washed precipitate at 120 °C for 12 h, and calcine it in a muffle furnace at 600 °C for 2 h. Cerium oxalate generates CeO2 under high temperature conditions, and CeO2 and Al2O3 are mixed during the smelting process to obtain the carrier Ce-Al2O3, where the Ce content is 20 wt%.

[0055] Step 2: Mix the platinum nitrate solution and cobalt nitrate and disperse them in deionized water to obtain a noble metal solution. For every 1 g of Pt, 9.7 g of cobalt nitrate powder is used, and for every 1 g of Pt, 500 mL of deionized water is used. Ultrasonic the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 97 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonic for 30 min to obtain a carrier solution. For every 1 g of Ce-Al2O3, 20 mL of deionized water is used. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, then quickly filter it inside the cylinder 1 to obtain a precipitate. Wash the precipitate clean inside the cylinder 1, and dry the washed precipitate at 80 - 120 °C to obtain the finished catalyst D. Reduce the catalyst D in an atmosphere of 10% H2 at 400 °C for 2 h.

[0056] Comparative Example 1

[0057] A method for preparing a catalyst for catalytic oxidation of methanol and hydrogen, specifically comprising the following steps:

[0058] Step 1: Prepare the support Ce-Al2O3: Disperse Al2O3 powder and cerium nitrate in deionized water, and ultrasonicate for 30 min. The mass ratio of Al2O3 to cerium nitrate is 8:5, and 40 mL of deionized water is added per 1 g of cerium nitrate. After ultrasonicating the solution, stir it and add ammonia water to adjust the pH to 8, and then add ammonia water to precipitate cerium oxalate. Continue to stir the solution for 5 h, and then pour the solution into the interior of the cylinder 1. The precipitate is quickly filtered and washed inside the cylinder 1. The washed precipitate is dried at 120 °C for 12 h and calcined in a muffle furnace at 600 °C for 2 h. Cerium oxalate generates CeO2 under high-temperature conditions, and CeO2 and Al2O3 are mixed during the melting process to obtain the support Ce-Al2O3, where Ce accounts for 20 wt%.

[0059] Step 2: Disperse platinum nitrate solution in deionized water to obtain a noble metal solution. 9.7 g of cobalt nitrate powder is added per 1 g of Pt, and 500 mL of deionized water is added per 1 g of Pt. Ultrasonicate the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 97 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonicate for 30 min to obtain a support solution, and 20 mL of deionized water is added per 1 g of Ce-Al2O3. Slowly add the noble metal solution to the support solution, perform ion exchange for 12 - 24 h, then put it into the interior of the cylinder 1 and quickly filter to obtain a precipitate. Wash the precipitate clean inside the cylinder 1, and dry the washed precipitate at 80 - 120 °C to obtain the finished catalyst E. Reduce the catalyst E in an atmosphere of 10% H2 at 400 °C for 2 h.

[0060] Perform performance evaluation on the catalyst samples A - E prepared in Examples 1 - 4 and Comparative Example 1: Perform activity evaluation of the prepared catalysts A - E for catalytic oxidation of methanol / H2. Test condition 1: The catalyst filling amount is 1 g, the methanol flow rate is 0.15 mL / min, and the flow rate of O2 with a concentration of 21% is 1000 mL / min. Test condition 2: The catalyst filling amount is 1 g, the H2 flow rate is 50 mL / min, and the flow rate of O2 with a concentration of 21% is 1000 mL / min; and thereby obtain the t of the catalyst sample 200 and the t of the catalyst sample 400 , and the specific results are listed in the attached Figure 9 and the attached Figure 10 .

[0061] From the attached Figure 9 and the attachedFigure 10 It can be seen that t 200 is the time required for catalytic combustion to reach 200 °C from room temperature, and t 400 is the time required for catalytic combustion to reach 400 °C from room temperature. The lower t 200 and t 400 are, the higher the activity of the catalyst is. Combining Examples 1 to 4 and Comparative Example 1, the activity of Experimental Example A (Pt:Fe = 1:2) is significantly improved compared with that of Comparative Example E (without Fe); Example D (Pt:Co = 1:2) is superior to the traditional catalyst. It can be seen that adding different promoters can all play a good promoting role in the catalyst, and reducing the noble metal loading can still maintain good catalytic activity; comparing with the patent document with the publication number CN112007682 (equal-volume impregnation + multiple calcination), the present invention adopts the ion exchange technology without high-temperature steps, and the active components are fixed by chemical bonds, solving the problems of uneven distribution and stability; Ce-Al2O3 and transition metals cooperate to break through the low-temperature activity bottleneck. In the prior art, the noble metal loading is high (≥1%) and the low-temperature activity is poor (t200 > 200 s), while in the present invention, the Pt loading is as low as 0.1% - 5% through ion exchange, and t200 < 160 s.

[0062] In summary, the finished catalyst obtained by the preparation method and reduction method of the present invention has good low-temperature catalytic activity.

[0063] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. An apparatus for preparing a catalyst for catalytic oxidation of methanol and hydrogen, characterized in that, Comprising: A cylinder body (1), at the top end of the cylinder body (1) is installed a compression mechanism (3) for adjusting the internal pressure of the cylinder body (1), and at the bottom end of the cylinder body (1) is installed a filtering mechanism (5) for filtering sediment, and inside the cylinder body (1) is installed a flushing mechanism (6) for cleaning the sediment clean; Inside the cylinder body (1) is installed an adjusting mechanism (4) for accelerating the sediment cleaning efficiency. The adjusting mechanism (4) includes a discharge pipe (41), the discharge pipe (41) is installed at the bottom end of the cylinder body (1), a backwashing pipe (42) is installed obliquely on the side wall of the discharge pipe (41), and the discharge pipe (41) is in threaded connection with an adjusting rod (43); inside the filtering mechanism (5) is installed a support column (45), inside the support column (45) is installed a fixing block (47), and the discharge pipe (41) is engaged inside the fixing block (47); the top end of the adjusting rod (43) is fixedly connected to a first piston (46) with an arc-shaped bottom side wall, and the first piston (46) is slidably connected inside the fixing block (47); at the top end of the first piston (46) is installed a second piston (48), on the side wall of the second piston (48) is installed a rubber pad (49) with a frustum-shaped surface, and the rubber pad (49) abuts against the surface of the fixing block (47). The diameter of the first piston (46) is equal to the inner diameter of the fixing block (47), and the inner diameter of the fixing block (47) is greater than the diameter of the second piston (48).

2. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 1, characterized in that, At the top end of the cylinder body (1) is installed a feed pipe (11), and at the bottom end of the cylinder body (1) with a funnel-shaped bottom is installed a sewage discharge pipe (12).

3. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 2, characterized in that, The compression mechanism (3) includes a hydraulic rod (31), the hydraulic rod (31) is installed on the surface of the cylinder body (1), a compression plate (34) is slidably connected inside the cylinder body (1), and the surface of the compression plate (34) is connected to the hydraulic rod (31); at both ends of the cylinder body (1) are respectively installed connecting pipes (32), and both ends of a communicating pipe (33) are respectively connected to the connecting pipes (32).

4. The preparation device of the catalyst for catalytically oxidizing methanol and hydrogen according to claim 3, characterized in that, The filtering mechanism (5) includes a support ring (51), the support ring (51) is fixedly connected inside the cylinder body (1), and a snap ring (52) is engaged inside the support ring (51); the cylinder body (1) is in threaded connection with multiple screw rods (57), and the screw rods (57) abut against the surface of the snap ring (52).

5. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 4, characterized in that, The filtering mechanism (5) further includes a support net (53), the support net (53) is installed inside the snap ring (52) through multiple bolts (56), multiple pressing rods (55) are fixedly connected inside the snap ring (52), a filter membrane (54) is laid between the pressing rods (55) and the support net (53); one end of the pressing rod (55) is fixedly connected to the support column (45), and the support column (45) penetrates through the filter membrane (54) and the support net (53).

6. The preparation device of the catalyst for catalytically oxidizing methanol and hydrogen according to claim 5, characterized in that, The flushing mechanism (6) includes a flushing pipe (61). A plurality of annular flushing pipes (61) are installed at the bottom end of the cylinder body (1). A water inlet pipe (64) and one of the connecting pipes (32) are communicated with the side wall of the flushing pipe (61). The flushing pipes (61) are communicated with each other through support rods (63). A plurality of nozzles (62) are installed on the side wall of each flushing pipe (61).

7. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 6, characterized in that, The nozzles (62) are inclined on the surface of the flushing pipe (61), and the orientation of the nozzles (62) gradually becomes vertical along the direction from the center of the cylinder body (1) to the edge of the cylinder body (1).

8. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 1, characterized in that, The top end of the discharge pipe (41) is funnel-shaped, and a gasket (44) is arranged between the discharge pipe (41) and the support column (45).

9. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 7, characterized in that, Valves (2) are installed on the side walls of the feed pipe (11), the sewage pipe (12), the connecting pipe (32), the communicating pipe (33), the discharge pipe (41), the backwash pipe (42), and the water inlet pipe (61).

10. The preparation device of the catalyst for catalytic oxidation of methanol and hydrogen according to claim 6, characterized in that, It includes a preparation method of a catalyst for catalytic oxidation of methanol and hydrogen, specifically including the following steps: Step 1: Prepare cerium-aluminum composite oxide: Calculate the corresponding Ce dissolved in water according to the ratio, add the corresponding Al2O3, and stir for 2 - 6 h, where the mass ratio of Ce to Al2O3 is 1:1 - 1:

20. Add a precipitant to form a precipitate inside the solution, and the precipitant includes one or more combinations of Na2CO3, NaOH, ammonia water, acetic acid, oxalic acid, etc. Then pour the solution into the inside of the cylinder body (1). The filtering mechanism (5) inside the cylinder body (1) separates the precipitate from the liquid. At the same time, the compression mechanism (3) operates to increase the pressure inside the cylinder body (1) and accelerate the filtering efficiency. After filtering, make the water spray out through the flushing mechanism (6) and the adjusting mechanism (4). The adjusting mechanism (4) makes the water drive the precipitate on the surface of the filtering mechanism (5) to move towards the outside of the cylinder body (1). The flushing mechanism (6) drives the water to flush the filtering mechanism (5) obliquely upwards, making the precipitate continuously turn upwards. And the compression mechanism (3) operates to drive the precipitate to continuously turn in the cleaning solution, accelerating the cleaning efficiency. The washed precipitate is dried at 120°C for 12 h and calcined in a muffle furnace at 400 - 600°C for 2 - 6 h to obtain the carrier Ce-Al2O3; Step 2: Mix the platinum-containing solution and the corresponding additive X solution and disperse them in deionized water to obtain a noble metal solution, where the X solution is one or a combination of solutions containing Co, Fe, Mn, Ni, Cu, and Zn elements. The mass ratio of Pt to additive X is 1:0 to 1:20, and 500 mL of deionized water is used per 1 g of Pt. Ultrasonic the mixed solution for 30 min. According to the following mass ratio: Pt: 1 part, Ce-Al2O3: 80 - 100 parts, disperse the Ce-Al2O3 obtained in Step 1 in deionized water and ultrasonic for 30 min to obtain a carrier solution, and 20 mL of deionized water is used per 1 g of Ce-Al2O3. Slowly add the noble metal solution to the carrier solution, perform ion exchange for 12 - 24 h, then quickly filter it into the inside of the cylinder (1) to obtain a precipitate. Wash the precipitate clean inside the cylinder (1), and dry the washed precipitate at 80 - 120 °C to obtain the finished catalyst.

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