Preparation method of transmission electron microscope sample containing molybdenum disulfide

Abstract

The invention provides a preparation method of a molybdenum disulfide-containing transmission electron microscope sample. The preparation method comprises the following steps: step 1, carrying out ultrasonic dispersion on a to-be-tested sample and an organic solvent; step 2, dropwise adding the supernatant dispersed in the step 1 onto a carbon film, and then drying the carbon film under a vacuum condition; and step 3, putting the dried carbon film into a carbon spraying instrument, and performing carbon spraying and film coating to obtain the transmission electron microscope sample. According to the preparation method of the molybdenum disulfide-containing transmission electron microscope sample, the problem that molybdenum disulfide is easily oxidized by air in the preparation process of the transmission electron microscope sample can be avoided, the method is simple, the preparation time is short, and a high-resolution transmission electron microscope image of a molybdenum disulfide stripe phase can be quickly obtained; the method is further used for catalyst structure and performance research.

Description

Technical Field

[0001] This invention belongs to the field of catalyst evaluation, specifically relating to a method for preparing molybdenum disulfide transmission electron microscopy samples. Background Technology

[0002] In industrial production, catalysts are required in 80% of the processes; hydrogenation catalysts are important transportation fuels and are vital to the national economy. Common hydrogenation catalysts include gasoline hydrogenation catalysts, diesel hydrogenation catalysts, jet fuel hydrogenation catalysts, lubricating oil hydrogenation catalysts, and residual oil hydrogenation catalysts. With increasingly stringent environmental regulations, restrictions are placed on the sulfur and polycyclic aromatic hydrocarbon (PAH) content in gasoline and diesel. Diesel product quality standards have been upgraded from National IV to National V, with the sulfur content requirement decreasing from 50 μg / g to 10 μg / g; and from National V to National VI, the PAH content requirement has decreased from 11% to 7%. The dual requirements of low sulfur and low aromatic hydrocarbons, along with the impact of inferior raw materials, pose a severe challenge to catalytic hydrogenation processes. Further improving the activity of hydrogenation catalysts has become a key research focus.

[0003] Improving catalyst activity requires a deeper understanding of the key active components. Transmission electron microscopy (TEM), a high-resolution, high-magnification microscope, can provide information on the microstructure, crystal structure, and chemical composition of extremely fine materials. The use of TEM to study the morphology and distribution of the molybdenum disulfide active phase in hydrogenation catalysts has gained increasing attention from catalyst researchers. Since the molybdenum disulfide active phase is easily oxidized when exposed to air, the sample preparation techniques for TEM directly affect the microstructure of the active phase; therefore, ensuring the intrinsic information of the sample is of paramount importance.

[0004] Molybdenum disulfide streaks in molybdenum disulfide samples react with oxygen in the air, transforming from molybdenum disulfide to molybdenum oxide. Therefore, solving the oxidation problem of molybdenum disulfide streaks in these samples is crucial for obtaining high-resolution transmission electron microscopy (TEM) images.

[0005] Currently, for molybdenum disulfide stripe phase samples, to prevent them from combining with air, the catalyst needs to be embedded in epoxy resin. After the epoxy resin cures, thin sections are cut out using ultrathin sections and transferred to an ultrathin carbon film for observation. Sample preparation takes two days. This process is time-consuming and costly.

[0006] Therefore, further research is needed in the field on the preparation of molybdenum disulfide transmission electron microscopy samples. Summary of the Invention

[0007] The main objective of this invention is to provide a method for preparing transmission electron microscopy (TEM) samples containing molybdenum disulfide, thereby overcoming the problem that molybdenum disulfide is easily oxidized by air during the preparation of TEM samples in the prior art.

[0008] To achieve the above objectives, the present invention provides a method for preparing a transmission electron microscopy sample containing molybdenum disulfide, comprising the following steps:

[0009] Step 1: Disperse the test sample with an organic solvent using ultrasonication;

[0010] Step 2: Take the supernatant from Step 1 and drop it onto the carbon film, then dry the carbon film under vacuum conditions;

[0011] Step 3: Place the dried carbon film into a carbon spraying instrument for carbon spraying coating to obtain a transmission electron microscope sample.

[0012] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention, wherein the sample to be tested is a sulfided hydrogenation catalyst, and the active component of the hydrogenation catalyst includes molybdenum.

[0013] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention, wherein the hydrogenation catalyst uses molybdenum disulfide stripe phase as the active component.

[0014] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention, wherein the organic solvent is at least one of anhydrous ethanol, n-hexane, and anhydrous methanol.

[0015] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention includes an ultrasonic dispersion process in which the ultrasonic dispersion frequency is 20-120 Hz and the dispersion time is 5-10 min.

[0016] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention includes step 1, in which the sample to be tested is ground with an organic solvent and then ultrasonically dispersed.

[0017] The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to the present invention, wherein the carbon film is a microgrid support film, an ultrathin carbon support film, or a pure carbon support film.

[0018] The method for preparing a transmission electron microscope sample containing molybdenum disulfide according to the present invention includes step 2, in which liquid is dropped onto a carbon film, the liquid droplets below the carbon film are absorbed, and then the carbon film is dried under vacuum conditions.

[0019] The method for preparing transmission electron microscopy samples containing molybdenum disulfide according to the present invention includes the following drying conditions: vacuum degree less than 400 Pa and drying time of 5-20 min.

[0020] The method for preparing transmission electron microscopy samples containing molybdenum disulfide according to the present invention includes a carbon spray coating with a thickness of 2-50 nm.

[0021] The beneficial effects of this invention are:

[0022] The method for preparing transmission electron microscopy (TEM) samples containing molybdenum disulfide of the present invention not only avoids the problem of molybdenum disulfide being easily oxidized by air during the preparation of TEM samples, but also has the advantages of being simple, quick to prepare, and able to rapidly obtain high-resolution TEM images of the molybdenum disulfide stripe phase, which can then be used for the study of catalyst structure and performance. Attached Figure Description

[0023] Figure 1 Transmission electron microscopy image of the catalyst sample in Example 1 of this invention;

[0024] Figure 2 Transmission electron microscopy image of the catalyst sample in Example 1 of this invention after being placed for 24 hours;

[0025] Figure 3 Transmission electron microscopy image of the catalyst sample in Example 2 of this invention;

[0026] Figure 4 Transmission electron microscopy image of the catalyst sample after 24 hours of storage in Example 2 of this invention;

[0027] Figure 5 Transmission electron microscopy image of the catalyst sample in Example 3 of this invention;

[0028] Figure 6 Transmission electron microscopy image of the catalyst sample after 24 hours of storage in Example 3 of this invention;

[0029] Figure 7 Transmission electron microscopy image of the catalyst sample in Example 4 of this invention;

[0030] Figure 8 Transmission electron microscopy image of the catalyst sample after 24 hours of storage in Example 4 of this invention;

[0031] Figure 9 Transmission electron microscopy image of the catalyst sample in Example 5 of this invention;

[0032] Figure 10 Transmission electron microscopy image of the catalyst sample in Example 5 of this invention after being placed for 24 hours;

[0033] Figure 11 Transmission electron microscope image of the catalyst sample of Comparative Example 1 of this invention;

[0034] Figure 12 Transmission electron microscope image of the catalyst sample of Comparative Example 1 of this invention after being placed for 24 hours;

[0035] Figure 13 Transmission electron microscope image of the catalyst sample of Comparative Example 2 of this invention;

[0036] Figure 14 Transmission electron microscope image of the catalyst sample of Comparative Example 2 of this invention after being placed for 24 hours;

[0037] Figure 15 Transmission electron microscope image of the catalyst sample of Comparative Example 3 of this invention;

[0038] Figure 16 Transmission electron microscope image of the catalyst sample of Comparative Example 4 of this invention;

[0039] Figure 17 Transmission electron microscope image of the catalyst sample of Comparative Example 5 of this invention;

[0040] Figure 18 Transmission electron microscopy image of the catalyst sample of Comparative Example 5 of this invention after being placed for 24 hours. Detailed Implementation

[0041] The technical solution of the present invention will be described in detail below. The following embodiments are implemented under the premise of the technical solution of the present invention and a detailed implementation process is given. However, the protection scope of the present invention is not limited to the following embodiments. Structures or experimental methods that do not specify specific conditions in the following embodiments are generally performed under conventional conditions.

[0042] This invention provides a method for preparing a transmission electron microscopy (TEM) sample containing molybdenum disulfide, comprising the following steps:

[0043] Step 1: Disperse the test sample with an organic solvent using ultrasonication;

[0044] Step 2: Take the supernatant from Step 1 and drop it onto the carbon film, then dry the carbon film under vacuum conditions;

[0045] Step 3: Place the dried carbon film into a carbon spraying instrument for carbon spraying coating to obtain a transmission electron microscope sample.

[0046] In this invention, the test sample is a hydrogenation catalyst in a sulfide state, and the active component of the hydrogenation catalyst includes molybdenum. In one embodiment, the hydrogenation catalyst uses the molybdenum disulfide streaky phase as the key active component. The method of this invention can avoid the problem of oxidation of the hydrogenation catalyst by air during the preparation of transmission electron microscopy samples; specifically, it can prevent the oxidation of molybdenum disulfide in the hydrogenation catalyst to molybdenum oxide. The method of this invention is rapid, simple, reliable, and does not damage the structure of the hydrogenation catalyst.

[0047] In one embodiment, the test sample of the present invention is stored in an organic solvent to isolate it from oxygen. In this invention, the organic solvent is a volatile organic solvent, such as at least one of anhydrous ethanol, n-hexane, and anhydrous methanol, preferably n-hexane. In one embodiment, the test sample and the organic solvent are first ground, and then ultrasonically dispersed. The grinding method is not particularly limited; for example, grinding can be performed in an agate mortar. In another embodiment, after grinding, a certain amount of organic solvent is added for ultrasonic dispersion. During ultrasonic dispersion, the ultrasonic dispersion frequency is 20-120 Hz, and the dispersion time is 5-10 min.

[0048] Then, the supernatant from step 1 is dropped onto the carbon film, and the carbon film is dried under vacuum. In one embodiment, after the liquid is dropped onto the carbon film, the droplets below the carbon film are blotted dry, and then the carbon film is dried under vacuum.

[0049] Among them, carbon film is carbon support film, such as microgrid support film, ultrathin carbon support film, pure carbon support film, pure carbon microgrid, lace microgrid, etc., with pure carbon microgrid support film being preferred.

[0050] The present invention does not impose a particular limitation on the amount of supernatant added to the carbon film, and those skilled in the art can adjust it as needed. In one embodiment, the vacuum drying conditions are: a vacuum degree of less than 400 Pa, or a vacuum degree of less than 800 Pa, or a vacuum degree of less than 1 Pa, preferably less than 1 Pa, and a drying time of 5-20 min.

[0051] Finally, the dried carbon film is placed in a carbon spraying instrument for carbon spraying coating to obtain a transmission electron microscope (TEM) sample. This invention does not particularly limit the carbon spraying instrument or the carbon spraying coating method; conventional methods in the art are acceptable. In one embodiment, the thickness of the carbon sprayed coating is 2-50 nm, for example, 2-10 nm, 10-20 nm, or 30-50 nm, preferably 10-20 nm. This coating provides excellent protection for the sample, does not affect the sample structure, and is simple and rapid to form. During testing, the active components of the TEM sample obtained by the method of this invention are not oxidized.

[0052] The technical solution of the present invention will be further described in detail below through specific embodiments. The catalysts described below are commercially available industrial catalysts.

[0053] Example 1

[0054] PHG201 sulfide-state hydrogenation catalyst was selected as the analytical sample. The catalyst particles, preserved in hexane, were removed and ground in an agate mortar with hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the pure carbon microgrid cooled, it was placed in a carbon sprayer and carbon coating was applied at a time of 10-20 nm. The sample was then placed in the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 1 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample is removed and stored in the sample box for 24 hours, it is loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM images are shown below. Figure 2 A large amount of molybdenum disulfide active phase can be clearly observed.

[0055] Example 2

[0056] PHG162 sulfide-state hydrogenation catalyst was selected as the analytical sample. The catalyst particles, preserved in hexane, were removed and ground in an agate mortar with hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the pure carbon microgrid cooled, it was placed in a carbon sprayer and carbon coating was applied at a time of 10-20 nm. The sample was then loaded into the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 3 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample was removed and stored in the sample box for 24 hours, it was loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 4 A large amount of molybdenum disulfide active phase can be clearly observed.

[0057] Example 3

[0058] PHD201 sulfurized unsupported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, preserved in hexane, were removed and ground in an agate mortar with hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the pure carbon microgrid cooled, it was placed in a carbon sprayer and carbon coating was applied at a time of 10-20 nm. The sample was then placed in the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 5 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample is removed and stored in the sample box for 24 hours, it is loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM images are shown below. Figure 6 A large amount of molybdenum disulfide active phase can be clearly observed.

[0059] Example 4

[0060] PHD201 sulfurized unsupported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, preserved in n-hexane, were removed and ground in an agate mortar with anhydrous ethanol for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of anhydrous ethanol. The centrifuge tube was then sonicated at 120 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the pure carbon microgrid cooled, it was placed in a carbon sprayer and carbon coating was applied at a time of 10-20 nm. The sample was then placed in the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 7 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample is removed and stored in the sample box for 24 hours, it is loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM images are shown below. Figure 8 A large amount of molybdenum disulfide active phase can be clearly observed.

[0061] Example 5

[0062] PHD201 sulfurized unsupported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, preserved in n-hexane, were removed and ground in an agate mortar with anhydrous methanol for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of anhydrous methanol. The centrifuge tube was then sonicated at 20 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the pure carbon microgrid cooled, it was placed in a carbon sprayer, and a carbon coating was applied at a time of 10-20 nm. The sample was placed in the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 9 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample is removed and stored in the sample box for 24 hours, it is loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM images are shown below. Figure 10 A large amount of molybdenum disulfide active phase can be clearly observed.

[0063] Example 6

[0064] PHG162 sulfide-state hydrogenation catalyst was selected as the analytical sample. The catalyst particles, preserved in hexane, were removed and ground in an agate mortar with hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to an ultrathin carbon film. The droplet was blotted dry with filter paper, and the ultrathin carbon film was placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. After the ultrathin carbon film cooled, it was placed in a carbon sprayer and carbon sprayed at a time of 10-20 nm. The sample was then loaded into the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The resulting TEM image is shown below. Figure 11 A large amount of molybdenum disulfide active phase can be clearly observed, but the image color is slightly dark and the contrast is poor. After the sample was removed and stored in the sample box for 24 hours, it was loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 12 A large amount of molybdenum disulfide active phase can be clearly observed, but the colors in the photo are slightly dark and the contrast is slightly poor.

[0065] Comparative Example 1

[0066] PHG162 sulfide-state hydrogenation catalyst was selected as the analytical sample. The catalyst particles, preserved in n-hexane, were removed and ground in an agate mortar with n-hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of n-hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid, and the droplet beneath the ultrathin carbon film was blotted dry with filter paper. The pure carbon microgrid was then placed in a vacuum chamber with a vacuum degree of 1 Pa for rapid vacuum drying. The sample was then loaded into the electron microscope sample holder, pre-evacuated for 45 minutes, and then pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 13 A large amount of molybdenum disulfide active phase can be clearly observed. After the sample was removed and stored in the sample box for 24 hours, it was loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 14 As can be seen, only a small amount of molybdenum disulfide active phase appears in the sample, and the molybdenum disulfide is oxidized during the storage process.

[0067] Comparative Example 2

[0068] PHD201 sulfurized unsupported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, stored in a sealed bag, were removed and ground in an agate mortar with anhydrous ethanol for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of n-hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was then placed under a heat lamp and dried for 15 minutes. After cooling, the pure carbon microgrid was loaded into the electron microscope sample holder. After pre-evacuating the electron microscope for 45 minutes, the sample was pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 15 It can be seen that only a small amount of molybdenum disulfide active phase appears in the sample. During storage and sample preparation, molybdenum disulfide is oxidized.

[0069] Comparative Example 3

[0070] PHD112 sulfurized supported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, preserved in hexane, were removed and ground in an agate mortar with hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid. The droplet below the pure carbon microgrid was blotted dry with filter paper. The pure carbon microgrid was placed on a temperature-controlled electric heating plate and dried at 200°C for 20 minutes. After cooling, the pure carbon microgrid was loaded into the electron microscope sample holder. After pre-evacuating the electron microscope for 45 minutes, the sample was pushed into the electron microscope vacuum system. The obtained TEM image is shown below. Figure 16 .Depend on Figure 16 As shown, the sample did not contain the active phase of molybdenum disulfide, indicating that molybdenum disulfide was oxidized during the sample preparation process.

[0071] Comparative Example 4

[0072] PHD201 sulfurized unsupported diesel hydrotreating catalyst was selected as the analytical sample. The catalyst particles, preserved in n-hexane, were removed and ground in an agate mortar with n-hexane for 5-10 minutes. A drop of the ground sample suspension was placed in a centrifuge tube and diluted with 1-2 mL of n-hexane. The centrifuge tube was then sonicated at 80 Hz for 10 minutes to disperse the sample. A drop of supernatant was added to a pure carbon microgrid, and the droplet below the microgrid was blotted dry with filter paper. The microgrid was then placed in a nitrogen-protected desiccator for 4 hours. The dried microgrid was then loaded into the electron microscope sample holder. After pre-evacuating the microscope for 45 minutes, the sample was pushed into the electron microscope vacuum system. The resulting TEM image... Figure 17 .Depend on Figure 17 As shown, although the sample exhibits numerous molybdenum disulfide streaks, the presence of solvent rings affects the identification performance of statistical software, and prolonged imaging of such samples will reduce the instrument's lifespan. After removing the sample and storing it in the sample box for 24 hours, the sample was loaded into the electron microscope and pre-vacuumed for 45 minutes before being pushed into the electron microscope's vacuum system. The resulting TEM image... Figure 18 ,Depend on Figure 18 As shown, only a small amount of molybdenum disulfide active phase appeared in the sample, and some of the molybdenum disulfide was oxidized during the storage process.

[0073] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a transmission electron microscopy sample containing molybdenum disulfide, characterized in that, Includes the following steps: Step 1: Disperse the test sample with an organic solvent using ultrasonication; Step 2: Take the supernatant from Step 1 and drop it onto the carbon film, then dry the carbon film under vacuum conditions; Step 3: Place the dried carbon film into a carbon spraying instrument for carbon spraying coating to obtain a transmission electron microscope sample.

2. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The test sample is a sulfided hydrogenation catalyst, and the active component of the hydrogenation catalyst includes molybdenum.

3. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The hydrogenation catalyst uses molybdenum disulfide stripe phase as the active component.

4. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The organic solvent is at least one of anhydrous ethanol, n-hexane, and anhydrous methanol.

5. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, In ultrasonic dispersion, the ultrasonic dispersion frequency is 20-120Hz, and the dispersion time is 5-10min.

6. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, Step 1: After grinding the test sample with the organic solvent, ultrasonic dispersion is then performed.

7. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The carbon film is a microgrid support film, an ultrathin carbon support film, or a pure carbon support film.

8. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, Step 2 involves adding liquid droplets to the carbon film, then absorbing the liquid droplets from the bottom of the carbon film, and finally drying the carbon film under vacuum conditions.

9. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The drying conditions are: vacuum degree less than 400 Pa, drying time 5-20 min.

10. The method for preparing a transmission electron microscopy sample containing molybdenum disulfide according to claim 1, characterized in that, The thickness of the carbon spray coating is 2-50nm.

Images