Metal net substrate for in-situ infrared testing and preparation method and application thereof
By preparing metal mesh substrates with specific materials and morphologies, the problem of difficult catalyst sample preparation was solved, enabling effective transmission and stable measurement of infrared light, and simplifying the sample preparation process for in-situ infrared testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-11-12
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies make it difficult to prepare catalyst samples that meet the requirements of in-situ infrared testing, especially thin and strong self-supporting sheets, which result in infrared light not being able to pass through or severe sample scattering effects, hindering in-situ measurements under high temperature, vacuum and other environments.
Using a metal mesh of a specific material and shape as a substrate, and through cleaning and fine grinding, an in-situ infrared testing metal mesh substrate is prepared to support catalyst samples, replacing the traditional self-supporting sample preparation.
It simplifies the sample preparation process, overcomes the limitations of catalyst physicochemical properties, achieves effective infrared light transmission, and ensures stable measurement under high temperature, vacuum and other environments.
Smart Images
Figure CN122016656A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of infrared spectroscopy testing technology, specifically relating to a metal mesh substrate for in-situ infrared testing, its preparation method, and its application. Background Technology
[0002] In-situ catalytic characterization is an advanced method for catalytic research, and in-situ molecular spectroscopy, especially in-situ infrared spectroscopy, is the most important tool for in-situ studies. When using in-situ infrared transmission spectroscopy for catalytic characterization, a key process is often involved: preparing a pure solid catalyst sample into a complete, uniform, self-supporting thin film with a diameter of 13 mm. Due to the influence of diffraction effects and the required spectral transmittance, the thickness of this thin film should be less than 100 micrometers. If the film is too thick, infrared light will not be able to pass through the sample; if the sample is incomplete, it will produce severe scattering effects; the sample film must also have sufficient strength, otherwise stable in-situ measurements cannot be performed under varying temperatures, vacuum, high pressure, or gas flow conditions. These stringent requirements for sample preparation increase the difficulty of implementing in-situ infrared characterization, because the properties of many catalysts are not conducive to preparing sample morphologies that meet measurement requirements: for example, some catalysts have poor formability and are difficult to effectively form into thin sheets with sufficient strength; some catalysts have a certain viscosity and are prone to adhering to the tablet mold and cannot be demolded; strong absorbing samples with extremely low transmittance, such as dark catalysts, must be made into thinner self-supporting sheets with a smaller sample volume to ensure infrared light transmission. Researchers and experimenters are often limited by the experimental techniques of in-situ infrared sample preparation, spending a lot of time and energy but failing to obtain high-quality data results, or even being directly blocked from the threshold of in-situ infrared characterization. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a metal mesh substrate for in-situ infrared testing, its preparation method, and its application. This invention uses a metal mesh of specific material and shape as a substrate for supporting sample preparation in in-situ infrared testing, completely replacing traditional self-supporting sample preparation. It overcomes the problem that various catalysts are limited by their physicochemical properties, making sample preparation difficult or resulting in poor performance.
[0004] One objective of this invention is to provide a metal mesh substrate for in-situ infrared testing, comprising a single-layer metal mesh finely ground with a polishing solution, wherein the metal mesh substrate is effective in the mid-infrared band (400–4000 cm⁻¹). -1 The light transmittance is 25-80%.
[0005] According to the present invention, the single-layer metal mesh has a mesh count of 20 to 120 (for example, the mesh count of the metal mesh can be 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120 mesh or any value between any two of the above ranges), and a wire diameter of 0.05 to 0.25 mm (for example, the wire diameter of the metal mesh can be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.21, 0.22, 0.23, 0.24, 0.25 mm or any value between any two of the above ranges); preferably, the single-layer metal mesh has a mesh count of 20 to 100 and a wire diameter of 0.09 to 0.2 mm.
[0006] According to the present invention, the metal material used in the metal mesh is selected from at least one of titanium, tungsten, and stainless steel.
[0007] The second objective of this invention is to provide a method for preparing the metal mesh substrate for in-situ infrared testing as described in the first objective of this invention, which includes the step of finely grinding the cleaned metal mesh with a polishing liquid.
[0008] According to the present invention, the method for preparing the metal mesh substrate for in-situ infrared testing specifically includes the following steps:
[0009] (1) Soak and clean the metal mesh in an alkaline solution for the first time, then soak and clean it in an acidic solution for the second time, and then dry it.
[0010] (2) The dried metal mesh obtained in step (1) is placed in a grinding and polishing machine for fine grinding, and then cleaned and dried to obtain the metal mesh substrate.
[0011] According to the present invention, in step (1) of the method for preparing the metal mesh substrate for in-situ infrared testing:
[0012] The alkaline compound in the alkaline solution is selected from at least one inorganic alkaline compound, preferably from at least one of sodium hydroxide and sodium carbonate;
[0013] The concentration of the alkaline compound in the alkaline solution can be adjusted within a wide range. Preferably, the concentration of the alkaline compound in the alkaline solution is 0.5 to 10 mol / L (for example, it can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 mol / L or any value between two of the above ranges), and more preferably 0.5 to 2 mol / L.
[0014] The acidic compound in the acidic solution is selected from at least one inorganic acid, preferably from at least one of HCl, carbonic acid, and nitrous acid;
[0015] The concentration of the acidic compound in the acidic solution can be adjusted within a wide range. Preferably, the concentration of the acidic compound in the acidic solution is 0.05 to 10 mol / L (for example, it can be 0.05, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10 mol / L or any value between any two of the above ranges), and more preferably 0.1 to 2 mol / L.
[0016] According to the present invention, in step (1) of the method for preparing the metal mesh substrate for in-situ infrared testing:
[0017] The soaking process is not particularly limited; it can be done by soaking thoroughly at room temperature. Preferably, the first soaking time is 1 to 12 hours, more preferably 1 to 6 hours; and the second soaking time is 1 to 12 hours, more preferably 1 to 6 hours.
[0018] The cleaning is performed using ultrasonic cleaning, preferably at a temperature of 0–45°C; the cleaning solvent is water.
[0019] In step (1), the drying can be carried out using drying equipment and drying conditions commonly used in the prior art. Preferably, the drying conditions in step (1) are: drying at 80-120℃ for 0.5-2 hours, and more preferably drying at 100-120℃ for 1-2 hours.
[0020] According to the present invention, in the method for preparing the metal mesh substrate for in-situ infrared testing:
[0021] The fine grinding process in step (2) can be achieved using a commonly used grinding and polishing machine (e.g., a metallographic polishing machine). Specifically, the conditions for the fine grinding process include:
[0022] Diamond grinding discs are used, preferably with a mesh size of 100 to 800.
[0023] Polyurethane polishing pads are used;
[0024] The polishing disc rotates at a speed of 10–60 r / min;
[0025] The polishing solution includes hydrogen peroxide, silicon dioxide, and water. Preferably, the concentration of hydrogen peroxide in the polishing solution is 1-5 wt%, and the concentration of silicon dioxide is 10-30 wt%. Commercially available silicon dioxide powder can be used as the silicon dioxide.
[0026] The flow rate of the polishing fluid is 1–10 mL / min, preferably 1–5 mL / min;
[0027] The polishing and grinding time is 1 to 30 minutes, preferably 5 to 15 minutes.
[0028] According to the present invention, in step (2) of the preparation method of the metal mesh substrate for in-situ infrared testing, the cleaning is carried out by ultrasonic cleaning. Preferably, the cleaning solvent is an alcohol solvent, the cleaning time is 30 to 180 min, and the cleaning temperature is not limited and can be completed at room temperature.
[0029] In step (2), the drying can be carried out using commonly used drying equipment and conditions in the prior art, as long as the metal mesh substrate is fully dried; for example, the drying conditions are: drying at 80-120℃ for 0.5-4 hours.
[0030] A third objective of this invention is to provide a method for in-situ infrared testing of solid catalysts, comprising the steps of spreading a catalyst sample on a metal mesh substrate, pressing it into a tablet, and then performing in-situ infrared testing. The metal mesh substrate is either the in-situ infrared testing metal mesh substrate described in one objective of this invention or the in-situ infrared testing metal mesh substrate obtained by the preparation method described in another objective of this invention. Preferably, the tableting conditions are: pressure of 0–4 MPa and time of 10–60 s.
[0031] This invention uses a metal mesh of a specific material and shape. After cleaning and fine grinding, the metal mesh substrate is used to support the sample preparation instead of pressing the sample to support the self-supporting thin sheet. This greatly simplifies the sample preparation process and overcomes the problem that various catalysts are difficult to prepare or have poor sample preparation results due to their own physicochemical properties. This makes in-situ infrared characterization of catalytic in-situ research methods easier to implement. Attached Figure Description
[0032] Figure 1 Image of the metal mesh substrate prepared in Example 1.
[0033] Figure 2 The transmittance curve of the metal mesh substrate prepared in Example 1 in the mid-infrared band.
[0034] Figure 3 The transmittance curve of the metal mesh substrate prepared in Example 2 in the mid-infrared band.
[0035] Figure 4 The transmittance curve of the metal mesh substrate prepared in Example 3 in the mid-infrared band.
[0036] Figure 5 The transmittance curve of the metal mesh substrate prepared in Example 4 in the mid-infrared band.
[0037] Figure 6The transmittance curve of the metal mesh substrate prepared in Example 5 in the mid-infrared band.
[0038] Figure 7 The transmittance curve of the metal mesh substrate prepared in Example 6 in the mid-infrared band.
[0039] Figure 8 The transmittance curve of the metal mesh substrate prepared in Example 7 in the mid-infrared band.
[0040] Figure 9 The transmittance curve of the metal mesh substrate prepared for Comparative Example 1 in the mid-infrared band.
[0041] Figure 10 The image shows the tablets prepared by using a metal mesh substrate to support the ZSM-5 molecular sieve catalyst in Test Example 1.
[0042] Figure 11 The images show the in-situ infrared spectra of the ZSM-5 molecular sieve catalyst tablets in Test Example 1 adsorbing pyridine at room temperature, 100℃, 150℃, 200℃, 300℃, and 400℃.
[0043] Figure 12 The image shows the tablets prepared by supporting the Co-Al catalyst on a metal mesh substrate in Test Example 2.
[0044] Figure 13 The image shows the in-situ infrared spectrum of CO adsorption at -150℃ after reduction of the Co-Al catalyst at 550℃ in Test Example 2. Detailed Implementation
[0045] This invention uses a metal screen of a specific shape, mesh size, and wire diameter, which, after cleaning and fine grinding, serves as a metal substrate for in-situ infrared testing. The preparation method of the metal substrate includes:
[0046] 1) Soak metal mesh of a certain mesh size (20-120 mesh) and a certain wire diameter (0.05mm-0.25mm) in a 0.5-10mol / L alkaline solution for 1-12 hours, rinse with clean water and ultrasonically (0-45℃), then soak in a 0.05-10mol / L acidic solution for 1-12 hours, rinse with clean water and ultrasonically (0-45℃), and dry at 80-120℃ for 0.5-2 hours.
[0047] 2) The metal mesh was placed in a metallographic polishing machine and finely ground using diamond grinding discs with a mesh size of 100-800. A polyurethane polishing pad was used, with the following settings: polishing disc speed (10-60 r / min), hydrogen peroxide concentration in the homemade polishing slurry (1-5 wt%), silica abrasive content (10-30 wt%), and slurry flow rate (1-10 mL / min). The polishing time was 1-30 minutes. During the experiment, a magnetic stirrer was used to continuously stir the homemade polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thus ensuring the accuracy and reliability of the experimental results.
[0048] 3) After polishing, use an alcohol solvent in an ultrasonic cleaner to ultrasonically clean the impurities, and then dry the product.
[0049] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.
[0050] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.
[0051] Example 1
[0052] A 316L metal mesh with a mesh size of 20 and a wire diameter of 0.2 mm was soaked in 1.0 mol / L NaOH for 2 hours, rinsed with water and ultrasonically (30℃), then soaked in 0.1 mol / L HCl for 4 hours, rinsed with water and ultrasonically (30℃), and dried at 110℃ for 1 hour.
[0053] The metal mesh was placed in a metallographic polishing machine and finely ground using a 100-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc rotation speed of 15 rpm, a hydrogen peroxide concentration of 1% in the self-made polishing slurry, a silica abrasive content of 10%, and a slurry flow rate of 1.0 mL / min. The polishing time was 5 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0054] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 80°C for 30 minutes to obtain the metal mesh substrate.
[0055] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 2 As shown.
[0056] Example 2
[0057] 316L metal mesh with a mesh size of 40 and a wire diameter of 0.15 mm was soaked in 1.0 mol / L NaOH for 4 hours, rinsed with water and ultrasonically (40℃), then soaked in 0.1 mol / L HCl for 6 hours, rinsed with water and ultrasonically (40℃), and dried at 110℃ for 1 hour.
[0058] The metal mesh was placed in a metallographic polishing machine and finely ground using a 200-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc speed of 30 rpm, a hydrogen peroxide concentration of 2% in the self-made polishing slurry, a silica abrasive content of 20%, and a slurry flow rate of 2.0 mL / min. The polishing time was 10 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform distribution of abrasive particles. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0059] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 100°C for 1 hour to obtain the metal mesh substrate.
[0060] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 3 As shown.
[0061] Example 3
[0062] A 50-mesh tungsten wire mesh with a diameter of 0.13 mm was soaked in 1.0 mol / L NaOH for 5 hours, rinsed with clean water using ultrasonication (20°C), then soaked in 0.1 mol / L HCl for 5 hours, rinsed with clean water using ultrasonication (20°C), and dried at 110°C for 2 hours.
[0063] The metal mesh was placed in a metallographic polishing machine and finely ground using a 500-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc speed of 45 rpm, a hydrogen peroxide concentration of 3% in the self-made polishing slurry, a silica abrasive content of 30%, and a slurry flow rate of 4.0 mL / min. The polishing time was 15 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0064] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 110℃ for 2 hours to obtain the metal mesh substrate.
[0065] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 4 As shown.
[0066] Example 4
[0067] A 60-mesh titanium mesh with a wire diameter of 0.1 mm was soaked in 1.0 mol / L NaOH for 6 hours, rinsed with water and ultrasonically (45℃), then soaked in 0.1 mol / L HCl for 6 hours, rinsed with water and ultrasonically (45℃), and dried at 110℃ for 2 hours.
[0068] The metal mesh was placed in a metallographic polishing machine and finely ground using an 800-mesh diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc speed of 60 rpm, a hydrogen peroxide concentration of 4% in the self-made polishing slurry, a silica abrasive content of 30%, and a slurry flow rate of 3.0 mL / min. The polishing time was 15 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0069] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 80°C for 3 hours to obtain the metal mesh substrate.
[0070] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 5 As shown.
[0071] Example 5
[0072] A titanium mesh with a mesh size of 80 and a wire diameter of 0.09 mm was soaked in 1.0 mol / L NaOH for 6 hours, rinsed with water and ultrasonically (45℃), then soaked in 0.1 mol / L HCl for 6 hours, rinsed with water and ultrasonically (45℃), and dried at 110℃ for 2 hours.
[0073] The metal mesh was placed in a metallographic polishing machine and finely ground using a 200-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc speed of 30 rpm, a hydrogen peroxide concentration of 4% in the self-made polishing slurry, a silica abrasive content of 30%, and a slurry flow rate of 5.0 mL / min. The polishing time was 15 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0074] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 90°C for 1 hour to obtain the metal mesh substrate.
[0075] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 6 As shown.
[0076] Example 6
[0077] A 316L metal mesh with a mesh size of 60 and a wire diameter of 0.1 mm was soaked in 1.0 mol / L NaOH for 6 hours, rinsed with water and ultrasonically (45℃), then soaked in 0.1 mol / L HCl for 6 hours, rinsed with water and ultrasonically (45℃), and dried at 110℃ for 2 hours.
[0078] The metal mesh was placed in a metallographic polishing machine and finely ground using a 200-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc rotation speed of 15 rpm, a hydrogen peroxide concentration of 5% in the self-made polishing slurry, a silica abrasive content of 10%, and a slurry flow rate of 1.0 mL / min. The polishing time was 5 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform abrasive distribution. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0079] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 120°C for 30 minutes to obtain the metal mesh substrate.
[0080] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 7 As shown.
[0081] Example 7
[0082] A 60-mesh tungsten wire mesh with a diameter of 0.1 mm was soaked in 1.0 mol / L NaOH for 6 hours, rinsed with water and ultrasonically (45℃), then soaked in 0.1 mol / L HCl for 6 hours, rinsed with water and ultrasonically (45℃), and dried at 110℃ for 2 hours.
[0083] The metal mesh was placed in a metallographic polishing machine and finely ground using a 400-grit diamond grinding wheel. A polyurethane polishing pad was used, with a polishing disc speed of 30 rpm, a hydrogen peroxide concentration of 1% in the self-made polishing slurry, a silica abrasive content of 20%, and a slurry flow rate of 5.0 mL / min. The polishing time was 10 minutes. During the experiment, a magnetic stirrer was used to continuously stir the self-made polishing slurry to ensure complete dissolution and uniform distribution of abrasive particles. A peristaltic pump was also used to precisely control the outlet flow rate of the polishing slurry, thereby ensuring the accuracy and reliability of the experimental results.
[0084] After polishing, the surface polishing solution was removed by ultrasonic cleaning with anhydrous ethanol in an ultrasonic cleaner for 30 minutes. The surface was then dried at 80°C for 4 hours to obtain the metal mesh substrate.
[0085] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 8 As shown.
[0086] Comparative Example 1
[0087] The method described in Example 4 is used, except that the 60-mesh titanium mesh with a wire diameter of 0.1 mm is replaced with a 150-mesh titanium mesh with a wire diameter of 0.1 mm.
[0088] The obtained metal mesh substrate was placed in the sample chamber of an infrared spectrometer, and its transmittance was measured in the mid-infrared band. The resulting transmittance curve is shown below. Figure 9 As shown, the transmittance is too low, making it unsuitable as a sample preparation sieve.
[0089] Test Example 1
[0090] The metal mesh substrate prepared in Example 1 was placed in a tableting mold. The ground ZSM-5 molecular sieve was evenly spread on the finished metal mesh. The pressure rod of the tableting mold was rotated to fill the sieve holes with the sample. A certain pressure (2MPa) was applied to the tableting mold using a tableting machine. After maintaining the pressure for a period of time (20s), the tableting mold was removed from the tableting machine, and the prepared metal mesh support sample was scraped off from the tableting mold. The metal mesh support sample sheet was subjected to high-temperature vacuum dehydration and degassing pretreatment at 500℃ and then cooled to room temperature. Pyridine was adsorbed for 1 hour, and then desorbed at room temperature, 100℃, 150℃, 200℃, 300℃, and 400℃ respectively. The desorption and adsorption infrared spectra at different temperatures were obtained, and the infrared spectral data test results were good. Figure 11 The results clearly show that ZSM-5 molecular sieve at 1450 cm⁻¹ -1 The nearby absorption peak is attributed to the characteristic peak of pyridine chemisorption at the L acid site, 1480 cm⁻¹. -1 The nearby absorption peak is the CH deformation vibration absorption peak on the pyridine molecular skeleton, at 1540 cm⁻¹. -1 The nearby absorption peaks are characteristic peaks of pyridine chemisorption at the Brønsted acid site.
[0091] Test Example 2
[0092] The metal mesh substrate prepared in Example 1 was placed in a tableting mold. The ground Co-Al catalyst was evenly spread on the finished metal mesh. The pressure rod of the tableting mold was rotated to fill the sieve holes with the sample. A certain pressure (4 MPa) was applied to the tableting mold using a tableting machine. After maintaining the pressure for a period of time (60 s), the tableting mold was removed from the tableting machine, and the prepared metal mesh support sample was scraped off the tableting mold. The metal mesh support sheet was reduced in a hydrogen atmosphere at 550 °C to activate the Co atom active centers on the catalyst surface. CO was adsorbed at -150 °C and different equilibrium pressures (100-900 Pa). The surface electronic effect was characterized by the d-π feedback effect (results are shown in Figure 1). Figure 13 (As shown). Figure 13 Two adsorption modes can be clearly observed at 2160 cm⁻¹. -1 The nearby absorption peak is attributed to adsorption on the Lewis acid center of the support, 2050 cm⁻¹ -1 The nearby absorption peaks are attributed to linear adsorption on Co atoms. The Co-Al catalyst involved in this test example is a very dark-colored sample, and it is difficult to form into a self-supporting sheet. The sample preparation obtained by the metal mesh support technique has excellent spectral transmittance, which provides a prerequisite for obtaining good characterization data results.
Claims
1. A metal mesh substrate for in-situ infrared testing, comprising a single-layer metal mesh finely ground with a polishing solution, wherein the metal mesh substrate has a transmittance of 25-80% in the mid-infrared band.
2. The metal mesh substrate according to claim 1, characterized in that, The single-layer metal mesh has a mesh count of 20 to 120 and a wire diameter of 0.05 to 0.25 mm; preferably, the single-layer metal mesh has a mesh count of 20 to 100 and a wire diameter of 0.09 to 0.2 mm.
3. The metal mesh substrate according to claim 1, characterized in that, The metal mesh is made of a metal material selected from at least one of titanium, tungsten, and stainless steel.
4. A method for preparing a metal mesh substrate for in-situ infrared testing as described in any one of claims 1 to 3, comprising the step of finely grinding the cleaned metal mesh with a polishing solution.
5. The preparation method according to claim 4, characterized in that, Specifically, the following steps are included: (1) Soak and clean the metal mesh in an alkaline solution for the first time, then soak and clean it in an acidic solution for the second time, and then dry it; (2) The dried metal mesh obtained in step (1) is placed in a grinding and polishing machine for fine grinding, and then cleaned and dried to obtain the metal mesh substrate.
6. The preparation method according to claim 5, characterized in that, In step (1): The alkaline compound in the alkaline solution is selected from at least one inorganic alkaline compound, preferably from at least one of sodium hydroxide and sodium carbonate; and / or, The concentration of the alkaline compound in the alkaline solution is 0.5–10 mol / L, preferably 0.5–2 mol / L; and / or, The acidic compound in the acidic solution is selected from at least one inorganic acid, preferably from at least one of HCl, carbonic acid, and nitrous acid; and / or, The concentration of the acidic compound in the acidic solution is 0.05–10 mol / L, preferably 0.1–2 mol / L.
7. The preparation method according to claim 5, characterized in that, In step (1): The first soaking time is 1–12 hours, preferably 1–6 hours; and / or, The second soaking time is 1–12 hours, preferably 1–6 hours; and / or, The cleaning is performed using ultrasonic cleaning, preferably at a temperature of 0–45°C; and / or, The drying conditions in step (1) are: drying at 80-120℃ for 0.5-2 hours, preferably at 100-120℃ for 1-2 hours.
8. The preparation method according to claim 5, characterized in that, The conditions for fine grinding in step (2) include: Diamond grinding discs are used, preferably with a mesh size of 100 to 800; and / or, Use polyurethane polishing pads; and / or, The polishing disc rotates at a speed of 10–60 r / min; and / or, The polishing solution comprises hydrogen peroxide, silica, and water. Preferably, the concentration of hydrogen peroxide in the polishing solution is 1–5 wt%, and the concentration of silica is 10–30 wt%; and / or, The flow rate of the polishing fluid is 1–10 mL / min, preferably 1–5 mL / min; and / or, The polishing and grinding time is 1 to 30 minutes, preferably 5 to 15 minutes.
9. The preparation method according to claim 5, characterized in that, In step (2), ultrasonic cleaning is used. Preferably, the cleaning solvent is an alcohol solvent, and the cleaning time is 30–180 min; and / or, The drying conditions in step (2) are: drying at 80-120℃ for 0.5-4 hours.
10. A method for in-situ infrared testing of a solid catalyst, comprising the steps of spreading a catalyst sample on a metal mesh substrate, pressing it into a tablet, and then performing in-situ infrared testing, wherein the metal mesh substrate is the metal mesh substrate for in-situ infrared testing as described in any one of claims 1 to 3 or the metal mesh substrate for in-situ infrared testing prepared by the preparation method described in any one of claims 4 to 9; preferably, the tableting conditions are: pressure of 0 to 4 MPa, and / or time of 10 to 60 s.