Molecular sieve acidity measuring method and device
By acquiring optical intensity data during the heating and desorption process of molecular sieve samples and analyzing the desorption peaks to characterize acid intensity, the problem of difficulty in measuring the acidity difference of molecular sieve particles in the prior art is solved, and the accurate measurement of the acidity of molecular sieve samples is achieved.
Patent Information
- Application Number
- CN202311865751.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-07-01
AI Technical Summary
The prior art is difficult to accurately measure the acidity difference between molecular sieve particles, resulting in the inability to effectively reflect the acidic properties of different molecular sieve particles.
By adsorbing the test gas for the molecular sieve sample to be tested and obtaining optical intensity data during the heating and desorption process, based on these data and desorption temperature, the desorption peak of the molecular sieve sample is obtained to characterize its acid intensity.
The accurate measurement of the acidity of molecular sieve samples is achieved, which can accurately reflect the acidic properties of different molecular sieve particles and improve the measurement accuracy.
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Figure CN120232886A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of molecular sieve catalyst processes, and particularly to a method and device for measuring the acidity of molecular sieves. Background Art
[0002] With the increasing demand for more efficient and highly selective catalysts, adsorbents, and separation membranes, the performance requirements for molecular sieves are also getting higher and higher. The acidity of molecular sieves reflects their performance in aspects such as catalysis, adsorption, and separation. Understanding the acidity of molecular sieves can evaluate their performance in catalysis, adsorption, and separation, and specific acidic requirements can be considered when synthesizing or selecting molecular sieves.
[0003] Currently, the technique widely used to characterize the acidity of molecular sieves is the ammonia temperature-programmed desorption (NH3-TPD) technique, which evaluates the acid strength of molecular sieves by analyzing the content of NH3 in the desorbed gas at different temperatures. However, due to the detection limit of the instrument, the amount of sample measured is often in the order of hundreds of milligrams, and the acidity result obtained is the average acidity of all molecular sieve particles in the sample, which cannot reflect the difference information between different molecular sieve particles. Summary of the Invention
[0004] The purpose of the embodiments of the present disclosure is to provide a method and device for measuring the acidity of molecular sieves.
[0005] To achieve the above purpose, the first aspect of the present disclosure provides a method for measuring the acidity of molecular sieves, the method comprising: allowing a molecular sieve sample to be measured to adsorb a test gas; performing temperature-programmed desorption on the adsorbed molecular sieve sample to obtain optical intensity data of the molecular sieve sample during the temperature-programmed desorption; and obtaining a desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature, and the magnitude of the desorption temperature corresponding to the desorption peak is used to characterize the acid strength of the molecular sieve sample.
[0006] In some embodiments, the molecular sieve sample comprises one or more molecular sieve particles, and the one or more molecular sieve particles are fixed on a carrier slide, and the surface of the carrier slide is coated with a metal thin film.
[0007] In some embodiments, the temperature-programmed desorption of the molecular sieve sample is achieved by controlling the voltage applied to the metal thin film, wherein the desorption temperature is positively correlated with the voltage.
[0008] In some embodiments, allowing the molecular sieve sample to be measured to adsorb a test gas comprises: removing moisture in the molecular sieve sample to be measured at a first temperature and in a first gas environment, the first temperature being the activation temperature of the molecular sieve sample and the first gas being an inert gas that does not chemically react with the molecular sieve sample; and allowing the dehydrated molecular sieve sample to adsorb a second gas at a second temperature and in a second gas environment, the second temperature being the adsorption temperature of the molecular sieve sample and the second gas being a test gas having the property of selectively adsorbing the acidic sites of the molecular sieve sample.
[0009] In some embodiments, based on the optical intensity data and the desorption temperature, a desorption peak of the molecular sieve sample is obtained, including: based on the optical intensity data and the desorption temperature, an optical intensity-temperature curve of the molecular sieve sample during the temperature-programmed desorption process is obtained; based on the optical intensity-temperature curve, an optical intensity change rate-temperature curve of the molecular sieve sample is obtained; based on the optical intensity change rate-temperature curve, the desorption peak is obtained, and the desorption peak is the maximum value of the optical intensity change rate-temperature curve.
[0010] In some embodiments, the optical intensity data is obtained by recording the dark-field optical image of the molecular sieve sample during the temperature-programmed desorption process.
[0011] A second aspect of the present disclosure provides a device for measuring the acidity of a molecular sieve. The device includes: an optical imaging unit for obtaining optical intensity data of the molecular sieve sample during the temperature-programmed desorption process; a temperature control unit for controlling the desorption temperature of the molecular sieve sample during the temperature-programmed desorption process; and a data processing unit for obtaining the desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature.
[0012] In some embodiments, the temperature control unit realizes the temperature-programmed desorption of the molecular sieve sample by changing the voltage applied to the metal film, wherein the desorption temperature is positively correlated with the voltage.
[0013] In some embodiments, the device further includes: a gas switching unit for controlling the gas environment of the molecular sieve sample.
[0014] A third aspect of the present disclosure provides a machine-readable storage medium having instructions stored thereon, and when the instructions are executed by a processor, the processor is configured to execute the above-mentioned molecular sieve acidity measurement method.
[0015] Through the above technical solutions, it is possible to in-situ monitor the optical intensity data of the molecular sieve sample during the temperature-programmed desorption process, and by analyzing the optical intensity data of the molecular sieve sample at different desorption temperatures, accurate measurement of the acidity of the molecular sieve sample is achieved.
[0016] Other features and advantages of the embodiments of the present disclosure will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings are used to provide a further understanding of the embodiments of the present disclosure, and constitute a part of the specification, and are used to explain the embodiments of the present disclosure together with the following specific implementation manners, but do not constitute a limitation to the embodiments of the present disclosure. In the drawings:
[0018] Figure 1 is a schematic flowchart of the molecular sieve acidity measurement method shown according to the embodiments of the present disclosure.
[0019] Figure 2 It is a schematic diagram of a dark-field optical imaging image of zeolite molecular sieve particles shown according to an embodiment of the present disclosure.
[0020] Figure 3 It is a schematic diagram of an optical intensity-temperature curve of zeolite molecular sieve particles during the temperature-programmed desorption process shown according to an embodiment of the present disclosure.
[0021] Figure 4 It is a schematic diagram of an optical intensity change rate-temperature curve of zeolite molecular sieve particles during the temperature-programmed desorption process shown according to an embodiment of the present disclosure.
[0022] Figure 5 It is a schematic structural diagram of a device for a method of measuring the acidity of zeolite molecular sieves shown according to an embodiment of the present disclosure.
[0023] Figure 6 It is a schematic flow diagram of a method for measuring the acidity of zeolite molecular sieves based on ammonia desorption shown according to an embodiment of the present disclosure.
[0024] Figure 7 It is a schematic block diagram of a device for a method of measuring the acidity of a zeolite molecular sieve sample shown according to an embodiment of the present disclosure. Detailed Embodiments
[0025] The following will describe in detail the specific embodiments of the embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the embodiments of the present disclosure, and are not intended to limit the embodiments of the present disclosure.
[0026] Zeolite molecular sieve particles are prepared by forming zeolite molecular sieve materials into particulate form. In zeolite molecular sieve particles, acidic sites generally refer to active centers with acidity existing in their lattice structure or on the surface, such as alumina (Al2O3) or silicate (SiO2), etc. These acidic sites can adsorb and chemically react with other substances. Taking ammonia temperature-programmed desorption as an example, when an ammonia temperature-programmed desorption experiment is carried out, ammonia molecules are introduced into zeolite molecular sieve particles as probe molecules. Since ammonia is a basic molecule, it will adsorb to the acidic sites in the zeolite molecular sieve particles. Subsequently, under the condition of heating, the sample is gradually heated. During the heating process, as the temperature rises, the interaction between the acidic sites in the zeolite molecular sieve particles and the adsorbed ammonia molecules gradually weakens, resulting in the desorption of ammonia molecules from the acidic sites. These desorbed ammonia molecules are released in the gas phase and detected and analyzed by detection devices such as mass spectrometers. The morphology, intensity, and position of the desorption peaks depend on the nature and quantity of the acidic sites. Different types and intensities of acidic sites will release ammonia molecules at different temperatures, so the position of the desorption peaks can provide information about the acidic sites.
[0027] That is, by studying the desorption peaks obtained from the ammonia content in the temperature-programmed desorption experiment of ammonia, the acidic sites of the molecular sieve particles can be quantitatively evaluated, and thus its acidity can be reflected. However, due to the detection limit of the instrument, the amount of the measured sample is often in the order of hundreds of milligrams, and the obtained acidity result is the average acidity of all the molecular sieve particles in the sample, which cannot reflect the difference information between different molecular sieve particles.
[0028] An embodiment of the present disclosure provides a method for measuring the acidity of a molecular sieve. By analyzing the optical intensity data of the molecular sieve particles, one or more desorption peaks of the molecular sieve particles can be obtained, and thus the acidity of one or more molecular sieve particles can be accurately reflected.
[0029] In the following embodiments of the present disclosure, the acidity may also be referred to as the acid strength, and the embodiments of the present disclosure do not make specific limitations thereto.
[0030] Figure 1 is a schematic flow chart of the method for measuring the acidity of a molecular sieve shown according to the embodiments of the present disclosure. As Figure 1 shown, the method includes the following steps: Step S101, allowing a molecular sieve sample to be measured to adsorb a test gas; Step S102, performing temperature-programmed desorption on the adsorbed molecular sieve sample to obtain optical intensity data of the molecular sieve sample during the temperature-programmed desorption process; Step S103, obtaining the desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature. Among them, the magnitude of the desorption temperature corresponding to the desorption peak is used to characterize the acid strength of the molecular sieve sample.
[0031] The method for measuring the acidity of a molecular sieve provided by the embodiments of the present disclosure can in-situ monitor the optical intensity data of the molecular sieve sample during the temperature-programmed desorption process, and by analyzing the optical intensity data of the molecular sieve sample at different desorption temperatures, the accurate measurement of the acidity of the molecular sieve sample can be realized.
[0032] The above steps S101-S103 are explained and described below.
[0033] Step S101, allowing a molecular sieve sample to be measured to adsorb a test gas.
[0034] In the embodiments of the present disclosure, the molecular sieve sample includes one or more molecular sieve particles. Among them, the molecular sieve sample may be a zeolite molecular sieve, such as SAPO-34 zeolite molecular sieve, ZSM-5 molecular sieve, etc.
[0035] In some embodiments, the adsorption of the test gas by the molecular sieve sample to be tested may include: removing the moisture in the molecular sieve sample to be tested at a first temperature and in a first gas environment, where the first temperature is the activation temperature of the molecular sieve sample and the first gas is an inert gas that does not chemically react with the molecular sieve sample; and adsorbing a second gas by the dehydrated molecular sieve sample at a second temperature and in a second gas environment, where the second temperature is the adsorption temperature of the molecular sieve sample and the second gas is a test gas having the property of selectively adsorbing the acidic sites of the molecular sieve sample.
[0036] In the above embodiments, the first gas may be nitrogen, or other inert gases that do not chemically react with the molecular sieve sample, such as argon, helium, etc. The second gas may be ammonia, or other adsorption gases having the property of selectively adsorbing the acidic sites of the molecular sieve sample. The first temperature may be 400 °C, or other suitable temperatures for activating the molecular sieve sample, such as 300 °C, 500 °C, etc. The second temperature may be 100 °C, or other temperatures at which the molecular sieve sample can adsorb the test gas, such as 150 °C, 90 °C, etc. For different molecular sieve samples, appropriate first gas, second gas, and control of appropriate first temperature and second temperature for dehydration and adsorption treatments can be selected, and specific limitations are not made in the embodiments of the present disclosure.
[0037] For ease of understanding, an example is given with the first gas being nitrogen, the second gas being ammonia, the first temperature being 400 °C, and the second temperature being 100 °C. The specific steps for the above-mentioned molecular sieve sample to be tested to adsorb the test gas may include the following steps.
[0038] Step 1: Raise the temperature of the molecular sieve sample to 400 °C, introduce nitrogen, and carry out activation dehydration of the molecular sieve sample for three minutes in the nitrogen gas environment.
[0039] Step 2: Lower the temperature of the dehydrated molecular sieve sample to 100 °C, introduce ammonia, and carry out adsorption of the dehydrated molecular sieve sample for three minutes in the ammonia gas environment.
[0040] Step 3: After the molecular sieve sample has completed adsorption, introduce nitrogen again to purge away the weakly adsorbed ammonia.
[0041] Among them, Step 1 can improve the adsorption capacity of the molecular sieve sample, so that ammonia can be fully adsorbed in Step 2, and Step 3 can purge away the weakly adsorbed ammonia. Since the adsorption force of ammonia on the molecular sieve sample is proportional to the acidity of the adsorption sites, the above steps can ensure that all the ammonia in the subsequent temperature-programmed desorption process is desorbed from the acidic sites of the molecular sieve sample, so that the change in optical intensity of the molecular sieve sample during the subsequent temperature-programmed desorption process can more accurately reflect the acid strength of the molecular sieve sample.
[0042] Step S102: Perform temperature-programmed desorption on the adsorbed molecular sieve sample to obtain the optical intensity data of the molecular sieve sample during temperature-programmed desorption.
[0043] In some embodiments, in order to observe the above-mentioned one or more molecular sieve particles, the above-mentioned one or more molecular sieve particles can be fixed on a slide. Among them, the surface of the slide is coated with a metal thin film.
[0044] In some embodiments, since temperature-programmed desorption of the molecular sieve sample requires linear heating of the molecular sieve sample, when the molecular sieve sample is fixed on the metal thin film of the slide, the desorption temperature can be controlled by controlling the voltage applied to the metal thin film. Among them, the desorption temperature increases with the increase of the voltage, that is, the desorption temperature is positively correlated with the voltage.
[0045] It should be noted that the metal thin film is composed of a series of orderly arranged lattices. When a voltage is applied to the metal thin film, current will pass through the metal thin film, which will cause collisions between electrons and metal ions and friction between electrons and lattices, thereby generating Joule heat. Joule heat is the heat generated when current passes through a resistor and can be calculated by the following formula:
[0046] Q = I^2 * R * t
[0047] Among them, Q represents Joule heat (unit: joule), I represents current (unit: ampere), R represents resistance (unit: ohm), and t represents time (unit: second).
[0048] According to Ohm's law, the relationship between current and voltage is:
[0049] I = V / R
[0050] Among them, I represents current (unit: ampere), V represents voltage (unit: volt), and R represents resistance (unit: ohm).
[0051] Substituting the expression of the above Ohm's law into the formula of Joule's law, we can get:
[0052] Q = (V^2 / R) * t
[0053] And electric power (P) represents the rate of energy conversion per unit time and can be defined as the ratio of Joule heat to time:
[0054] P = Q / t = (V^2 / R)
[0055] According to the above formula, when the resistance of the metal thin film is fixed, when the voltage increases, the electric power and Joule heat will increase accordingly. In the embodiments of the present disclosure, a non-linear voltage curve can be applied to obtain a linear increase in power and thus a linear heating curve.
[0056] In some embodiments, the optical intensity data of the molecular sieve sample can be obtained by recording the dark-field optical images of the molecular sieve sample during the temperature-programmed desorption process.
[0057] It should be noted that dark-field optical imaging is a microscopic imaging technique based on the scattered light on the sample surface. Its principle is to generate a dark field on the sample surface through optical path design and selection of a suitable carrier slide, and only the scattered light on the sample surface can be detected, so as to achieve high-sensitivity detection and imaging of the surface topography information and particle distribution of the sample.
[0058] In some embodiments, a white light source can be selected for dark-field optical imaging, so that the surface of the molecular sieve sample scatters light of different wavelengths, thereby obtaining the scattered light information of the molecular sieve sample at different wavelengths and converting it into corresponding dark-field optical imaging images. As Figure 2 shown, the dark-field optical imaging image can reflect the optical intensity of the molecular sieve sample, where Figure 2 a bright spot represents a molecular sieve particle. Multiple molecular sieve particles can be observed at an observation scale of 10 micrometers (um), and at an observation scale of 1 micrometer (um), a single molecular sieve particle can be observed. In the embodiments of the present disclosure, any one of the molecular sieve particles can be selected for analysis, for example, molecular sieve particle a is selected for analysis. During the temperature-programmed desorption process of molecular sieve particle a, multiple dark-field optical imaging images of molecular sieve particle a can be obtained, and then the optical intensity data of molecular sieve particle a during the temperature-programmed desorption process can be obtained.
[0059] The above-mentioned use of dark-field optical imaging technology can not only observe multiple molecular sieve particles in the molecular sieve sample, but also observe a single molecular sieve particle in the molecular sieve sample, and then can accurately obtain the optical intensity data of one or more molecular sieve particles in the molecular sieve sample.
[0060] Step S103, based on the optical intensity data and the desorption temperature, obtain the desorption peak of the molecular sieve sample.
[0061] First, based on the optical intensity data and the desorption temperature, an optical intensity-temperature curve of a certain molecular sieve particle in the molecular sieve sample during the temperature-programmed desorption process as shown in Figure 3 can be obtained. It should be noted that since dark-field optical imaging is sensitive to the mass change of particles, and the mass of the molecular sieve particle also decreases during the temperature-programmed desorption process of the molecular sieve particle, which will reduce the dark-field optical intensity. Therefore, the above-mentioned optical intensity-temperature curve can reflect the mass change of the molecular sieve particle, that is, it can reflect the change in the desorption gas content of the molecular sieve particle.
[0062] Furthermore, based on as Figure 3From the optical intensity temperature curve shown, it can be obtained that Figure 4 the temperature curve of the optical intensity change rate corresponding to a certain molecular sieve particle in the molecular sieve sample during the heating desorption process as shown. Among them, the above-mentioned temperature curve of the optical intensity change rate is obtained by converting according to Figure 3 the slope of the optical intensity temperature curve shown.
[0063] Furthermore, based on the above-mentioned temperature curve of the optical intensity change rate, the desorption peak of the molecular sieve sample can be obtained. The maximum value of the temperature curve of the optical intensity change rate is the desorption peak of the molecular sieve sample. Refer to Figure 4 , the maximum value of the temperature curve of the optical intensity change rate is 127.81 °C, that is, the desorption peak is 127.81 °C, indicating that the acid strength of the molecular sieve particle is weak acid.
[0064] In some embodiments, there can be multiple maximum values of the temperature curve of the optical intensity change rate, that is, corresponding to multiple desorption peaks, and different desorption peaks can be used to characterize the acid strengths of different acidic sites.
[0065] In the embodiments of the present disclosure, by analyzing the change in the optical intensity of the particles during the heating desorption process of the molecular sieve sample, the heating desorption process of one or more molecular sieve particles can be monitored in-situ and in real-time. After further correlating with the desorption temperature, the desorption peak of one or more molecular sieve particles can be obtained to characterize the acid strength of one or more molecular sieve particles.
[0066] For easy understanding, the following combines Figure 5 and Figure 6 to specifically illustrate the above-mentioned molecular sieve acidity measurement method by way of examples.
[0067] Figure 5 is a schematic structural diagram of the device for the molecular sieve acidity measurement method shown according to the embodiments of the present disclosure. As Figure 5As shown, the device includes an injection pump 1, a six-way valve 2, a dark-field optical imager 3, a function generator 4, and an electrochemical workstation 5. Among them, the injection pump 1 is connected to the six-way valve 2, the six-way valve 2 is connected to the air inlet in the dark-field optical imager 3 through a catheter, the wafer with a metal thin film plated in the dark-field optical imager 3 is connected to the electrochemical workstation 5 through a wire, and the electrochemical workstation is connected to the function generator 4. The injection pump 1 is used to output nitrogen (N2) or ammonia (NH3), the six-way valve 2 is used to control the switching of nitrogen (N2) or ammonia (NH3), and output nitrogen (N2) or ammonia (NH3) to the dark-field optical imager 3. The dark-field optical imager 3 also includes an air outlet for discharging nitrogen (N2) or ammonia (NH3). The function generator 4 is controlled by a computer. The computer writes a voltage curve and sends it to the function generator 4. The function generator 4 sends the voltage to the electrochemical workstation 5 and outputs it to the metal thin film, and then uses the Joule heat generated by the metal thin film to provide the required temperature. The device also includes a data acquisition card for recording temperature data and dark-field optical imaging data.
[0068] Figure 6 is a schematic flowchart of a method for measuring the acidity of zeolite molecular sieves based on ammonia desorption shown according to an embodiment of the present disclosure. This method can be implemented by a device as shown in Figure 5 shown. As shown in Figure 6 shown, this method includes the following steps.
[0069] Step S201, fix multiple zeolite molecular sieve particles on a wafer with a metal thin film plated on its surface.
[0070] Step S202, place the wafer on the dark-field optical imager and perform optical path adjustment and optical focusing.
[0071] Step S203, raise the temperature of the wafer surface to 400 °C, introduce nitrogen, and activate and remove water from the zeolite molecular sieve particles for three minutes.
[0072] Step S204, lower the temperature of the wafer surface to 100 °C, switch from introducing nitrogen to introducing ammonia, and allow the zeolite molecular sieve particles to adsorb ammonia for three minutes.
[0073] Step S205, after adsorption, switch from introducing ammonia to introducing nitrogen to purge away weakly adsorbed ammonia.
[0074] Step S206, perform linear temperature programmed desorption on the zeolite molecular sieve particles and record the dark-field optical images of the zeolite molecular sieve particles during the linear temperature programmed desorption process.
[0075] Step S207, based on the dark-field optical images, obtain the optical intensity data of the zeolite molecular sieve particles during the linear temperature programmed desorption process and perform analysis to obtain the desorption peak of the zeolite molecular sieve particles.
[0076] Among them, the descriptions of steps S201 - S205 can refer to the above description of step S101, and the descriptions of steps 206 - S207 can refer to the above descriptions of steps S102 - S103, and will not be elaborated here.
[0077] Through the technical solutions of the above various embodiments of the present disclosure, a method for measuring the acidity of molecular sieves based on optical imaging technology is provided, realizing the acidity measurement of single or multiple molecular sieve particles, and improving the accuracy of acidity measurement of molecular sieve particles.
[0078] It should be understood that although Figure 1 and Figure 6 the steps in the flowcharts of Figure 1 and Figure 6 are shown in sequence according to the indication of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover,
[0079] Figure 7 is a structural block diagram of a device for a method for measuring the acidity of a molecular sieve sample shown according to an embodiment of the present disclosure. As Figure 7 shown, the device 100 includes an optical imaging unit 110, a temperature control unit 120, a data processing unit 130, and a gas switching unit 140. Among them, the optical imaging unit 110 is used to obtain the optical intensity data of the molecular sieve sample during the temperature-programmed desorption process, the temperature control unit 120 is used to control the desorption temperature of the molecular sieve sample during the temperature-programmed desorption process, and the data processing unit 130 is used to obtain the desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature.
[0080] In some embodiments, the temperature control unit 120 realizes the temperature-programmed desorption of the molecular sieve sample by changing the voltage applied to the metal thin film, where the desorption temperature is positively correlated with the voltage.
[0081] For the specific details and benefits of the device for the method for measuring the acidity of a molecular sieve sample provided by the embodiments of the present disclosure, reference can be made to the above description of the method for measuring the acidity of a molecular sieve, and will not be elaborated here.
[0082] Embodiments of the present disclosure provide a machine-readable storage medium with a program stored thereon, and when the program is executed by a processor, the above-described method for measuring the acidity of molecular sieves is implemented.
[0083] Those skilled in the art should understand that the embodiments of the present disclosure may be provided as a method, a system, or a computer program product. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0084] The present disclosure is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or multiple flows and / or blocks
[0085] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one or more of the flows Figure 1 or multiple flows and / or blocks
[0086] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the flows Figure 1 or multiple flows and / or blocks
[0087] In a typical configuration, a computing device includes one or more processors (CPUs), an input / output interface, a network interface, and a memory.
[0088] The memory may include non-permanent memory in the form of computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.
[0089] Computer-readable media includes both permanent and non-permanent, removable and non-removable media and can store information by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.
[0090] It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article or apparatus comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or apparatus. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising the element.
[0091] The above are only embodiments of the present disclosure and are not used to limit the present disclosure. For those skilled in the art, various changes and modifications can be made to the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the scope of the claims of the present disclosure.
Claims
1. A method for measuring the acidity of a molecular sieve, characterized in that, The method includes: Letting a molecular sieve sample to be measured adsorb a test gas; Performing temperature-programmed desorption on the adsorbed molecular sieve sample to obtain optical intensity data of the molecular sieve sample during the temperature-programmed desorption; Based on the optical intensity data and the desorption temperature, obtaining a desorption peak of the molecular sieve sample, and the magnitude of the desorption temperature corresponding to the desorption peak is used to characterize the acid strength of the molecular sieve sample.
2. The method according to claim 1, wherein The molecular sieve sample includes one or more molecular sieve particles, the one or more molecular sieve particles are fixed on a slide, and a metal film is plated on the surface of the slide.
3. The method according to claim 2, wherein The temperature-programmed desorption of the molecular sieve sample is realized by controlling the voltage applied to the metal film, wherein the desorption temperature is positively correlated with the voltage.
4. The method according to claim 1, characterized in that, The letting the molecular sieve sample to be measured adsorb the test gas includes: Removing moisture in the molecular sieve sample to be measured at a first temperature and in a first gas environment, the first temperature being the activation temperature of the molecular sieve sample, and the first gas being an inert gas that does not chemically react with the molecular sieve sample; Letting the dehydrated molecular sieve sample adsorb a second gas at a second temperature and in a second gas environment, the second temperature being the adsorption temperature of the molecular sieve sample, and the second gas being a test gas having the performance of selectively adsorbing the acidic sites of the molecular sieve sample.
5. The method according to claim 1, wherein The obtaining the desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature includes: Based on the optical intensity data and the desorption temperature, obtaining an optical intensity-temperature curve of the molecular sieve sample during the temperature-programmed desorption; Based on the optical intensity-temperature curve, obtaining an optical intensity change rate-temperature curve of the molecular sieve sample; Based on the optical intensity change rate-temperature curve, obtaining the desorption peak, and the desorption peak is the maximum value of the optical intensity change rate-temperature curve.
6. The method according to claim 1 or 5, characterized in that The optical intensity data is obtained by recording the dark-field optical image of the molecular sieve sample during the temperature-programmed desorption.
7. An apparatus for measuring the acidity of molecular sieves, characterized in that, The device includes: An optical imaging unit for obtaining optical intensity data of the molecular sieve sample during the temperature-programmed desorption; A temperature control unit for controlling the desorption temperature of the molecular sieve sample during the temperature-programmed desorption; A data processing unit for obtaining the desorption peak of the molecular sieve sample based on the optical intensity data and the desorption temperature.
8. The device according to claim 7, characterized in that, The temperature control unit realizes the temperature-programmed desorption of the molecular sieve sample by changing the voltage applied to the metal film, wherein the desorption temperature is positively correlated with the voltage.
9. The device according to claim 7, characterized in that, The device further includes: A gas switching unit for controlling the gas environment of the molecular sieve sample.
10. A machine-readable storage medium having instructions stored thereon, characterized in that, When the instruction is executed by a processor, the processor is configured to execute the molecular sieve acidity measurement method according to any one of claims 1-6.