Time-resolved synchrotron radiation X-ray absorption spectrum and mass spectrum combined test system

Abstract

The utility model discloses a time-resolved synchrotron radiation X-ray absorption spectrum and mass spectrum combined test system. The system comprises a light source, a fast scanning monochromator, a slit, a first ionization chamber, a sample chamber and a second ionization chamber which are sequentially arranged in the X-ray propagation direction, a fluorescence detector or a solid detector which is arranged perpendicular to the optical axis of the sample chamber, and a mass spectrometer which is connected with the tail end of the sample chamber, the data acquisition system is connected with the first ionization chamber, the second ionization chamber and the mass spectrometer at the same time and can obtain time-resolved XAS spectrogram information of the sample and MS spectrogram information of real-time changes of reactants and products in the reaction process. The system combines the rapid and high-precision structure and electronic state analysis capability of time-resolved synchrotron radiation X-ray absorption spectrum (QXAFS) and the high-sensitivity substance real-time detection capability of mass spectrum (MS) analysis technology, and realizes real-time monitoring of dynamic change of a catalyst structure and distribution of reactants and products.

Description

Technical Field

[0001] The utility model belongs to the field of analysis and testing, and specifically relates to a time-resolved synchrotron radiation X-ray absorption spectrum and mass spectrometry combined testing system. Background Art

[0002] In research fields such as materials science, chemistry, and physics, a deep understanding of material structure, composition, and reaction mechanisms is crucial for the design of new materials, the improvement of catalysts, and the optimization of chemical reactions. Traditional material and substance analysis methods, such as X-ray diffraction (XRD), infrared spectroscopy (IR), X-ray absorption spectroscopy (XAS), and mass spectrometry (MS), while widely used in specific fields, often fail to provide comprehensive information on both material structure and chemical changes simultaneously.

[0003] In recent years, synchrotron X-ray technology has been widely used in materials science due to its high energy, high brightness, and high penetration. Synchrotron X-ray absorption spectroscopy (XAS) provides detailed information about the electronic structure and chemical bonds of atoms in materials, making it crucial for studying electronic properties, catalytic activity, and reaction mechanisms. It is also less susceptible to environmental interference. Time-resolved synchrotron X-ray absorption spectroscopy, with its millisecond and second-scale spectral acquisition capabilities, allows for real-time monitoring of dynamic structural changes in materials. Mass spectrometry (MS) is a powerful chemical analysis tool widely used in catalyst evaluation, reaction kinetics, and chemical analysis. It accurately detects and analyzes material information in real time, revealing product distribution and reaction mechanisms. Combining time-resolved synchrotron X-ray absorption spectroscopy with mass spectrometry allows comprehensive information about material structure and chemical changes in reactants and products during reactions to be obtained on the same experimental platform. Therefore, developing a combined measurement system that can simultaneously utilize time-resolved synchrotron X-ray absorption spectroscopy and mass spectrometry has significant scientific significance and application value for materials science and chemistry research. Utility Model Content

[0004] The purpose of the utility model is to provide a time-resolved synchrotron radiation X-ray absorption spectrum and mass spectrometry test system, and to use the technology to study the structure-activity relationship in the catalytic reaction process.

[0005] The utility model adopts the following technical solutions:

[0006] A time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry test system is provided, comprising: a light source, a fast-scanning monochromator, a slit, a first ionization chamber, a sample chamber, and a second ionization chamber arranged in sequence in the direction of X-ray propagation; a fluorescence detector or a solid-state detector arranged perpendicular to the optical axis of the sample chamber; and a mass spectrometer connected to the end of the sample chamber; and a data acquisition system connected to the first and second ionization chambers and the mass spectrometer. The data acquisition system can obtain time-resolved XAS spectrum information of the sample and MS spectrum information of real-time changes of reactants and products during the reaction process.

[0007] Preferably, it also includes a standard sample stage and a third ionization chamber which are sequentially arranged after the second ionization chamber in the direction of X-ray propagation, the standard sample stage is used to place a standard sample, and the third ionization chamber is connected to the data acquisition system to detect the X-ray absorption data of the standard sample to achieve calibration of the X-ray energy.

[0008] Preferably, the sample chamber is a sealed cavity structure, a sample holder is provided inside for placing the test sample, the sample chamber has a hole slot that is transparent to X-rays, and the hole slot is sealed by a beryllium window.

[0009] Preferably, the sample chamber has a heating and heat preservation function and has an air inlet at the bottom. The front end of the air inlet is connected to a mass flow control system to facilitate accurate control of the gas flow.

[0010] Preferably, the top of the sample chamber is connected to a three-way interface, one end of which is connected to a mass spectrometer for receiving and analyzing gas molecules in the sample chamber to detect the components of reactants and products, and the other end is connected to an exhaust port for exhausting gas.

[0011] Preferably, the solid-state detector is a silicon drift detector or a 32-element germanium detector.

[0012] Preferably, the position of the sample chamber is adjustable to obtain the best optical signal. The sample chamber is placed on a sample stage, which can be precisely adjusted in the X-axis and Y-axis by an electric motor.

[0013] When the transmission method is used, the test sample is arranged in a vertical direction in the sample chamber. When the fluorescence method is used, the test sample is arranged in the sample chamber at an angle of 45 degrees to the vertical direction.

[0014] Furthermore, the data acquisition system can generate corresponding time-resolved X-ray absorption spectrum data. By analyzing these data, detailed information about the electronic structure and chemical bonds of atoms in the material during the transient reaction process can be obtained.

[0015] Furthermore, a mass spectrometer is connected to the sample chamber to receive and analyze the gas molecules generated in the sample chamber. Through mass spectrometry, the gas molecules in the sample can be detected and analyzed in real time and accurately, thereby revealing the distribution of products and the mechanism of chemical reactions.

[0016] Furthermore, the data acquisition and processing unit is used to combine the time-resolved X-ray absorption spectrum data and the mass spectrometer data to obtain real-time information on the structural changes of the material and the chemical changes during the reaction, and to analyze the structure-activity relationship of the catalyst.

[0017] According to the time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system provided by the utility model, researchers can simultaneously obtain comprehensive information on material structure and chemical changes on the same experimental platform. This comprehensive capability not only helps to deeply understand the electronic properties, catalytic activity and reaction mechanism of the material, but also provides strong technical support for the design of new materials, the improvement of catalysts and the optimization of chemical reactions, helping to open the black box of the catalytic reaction process.

[0018] Compared with the prior art, the present invention has the following significant beneficial effects:

[0019] 1) Efficiency: By using time-resolved XAS and MS simultaneously, a large amount of useful data can be obtained in a short period of time, improving experimental efficiency;

[0020] 2) Accuracy: Time-resolved XAS and MS techniques each have unique advantages. When used in combination, they can complement each other and improve the accuracy and reliability of data analysis.

[0021] 3) Flexibility: The combination of transmission and fluorescence modes enables the system to adapt to samples of different properties and meet different experimental needs;

[0022] 4) Visualization: The visual interface of the data acquisition and processing unit makes the viewing and analysis of experimental data more intuitive and convenient.

[0023] In summary, the utility model provides a time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system for catalyst structure-activity relationship analysis. The system combines the advantages of time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry technology, can simultaneously obtain comprehensive information on material structure and chemical changes, and provides strong technical support for materials science and chemical research. It has broad application prospects and important scientific significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a time-resolved synchrotron radiation X-ray absorption spectrometry and mass spectrometry testing system according to a preferred embodiment of the present invention, wherein A is a transmission method and B is a fluorescence method;

[0025] Figure 2 The time-resolved synchrotron X-ray absorption spectrum obtained according to Example 1 of the present invention includes QXAFS data (A), XANES data (B) and EXAFS data (C);

[0026] Figure 3 The mass spectrum obtained according to Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to specific examples. It should be understood that the following examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Unless otherwise specified, the techniques used in the examples are conventional in the art or in accordance with the experimental methods recommended by the instrument and equipment manufacturers. The reagents and materials used in the examples are commercially available unless otherwise specified.

[0028] According to a preferred embodiment of the present invention, a time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system is provided, such as Figure 1 shown.

[0029] The system includes: a light source, a fast-scan monochromator 1, a slit, a first ionization chamber 2, a sample chamber 3, a second ionization chamber 4, a standard sample stage 5 and a third ionization chamber 6 arranged in sequence in the direction of X-ray propagation; a fluorescence detector or a solid-state detector 7 arranged perpendicular to the optical axis of the sample chamber; a mass spectrometer 8 connected to the end of the sample chamber 3; and a data acquisition system (not shown) connected to the first and second ionization chambers and the mass spectrometer. The data acquisition system can obtain time-resolved XAS spectrum information of the sample, as well as MS spectrum information of real-time changes in reactants and products during the reaction process.

[0030] The test system includes two test methods: transmission method and fluorescence method. The working principle of the transmission method is as follows: Figure 1 As shown in the figure above: After X-rays pass through the sample, they will be partially absorbed by the sample. The signal of the sample will be different before and after X-ray absorption. By comparing the signal difference before and after the ionization chamber, the absorption signal data of the sample can be obtained. The working principle of the fluorescence method is as follows Figure 1 As shown in the figure below: A technique for elemental analysis that uses X-rays to excite a sample and measure the resulting fluorescent X-rays.

[0031] The testing method of the test system includes the following steps:

[0032] 1) Calibrate the X-ray energy and adjust the position of the sample chamber (including height, angle, etc.) to obtain the best optical signal. By observing the X-ray signal after passing through the sample, when the signal intensity is the highest, the optical signal is the strongest.

[0033] 2) Press the sample into a tablet, place it on a holder in the sample chamber, start the mass spectrometer, and set the corresponding scanning range;

[0034] 3) Adjust the temperature and different atmosphere compositions of the sample chamber to acquire time-resolved XAS and MS data in real time.

[0035] Example 1

[0036] Taking Pt as the element to be tested, the process of detecting Pt / Fe2O3 in the CO oxidation reaction is taken as an example, which specifically includes the following steps:

[0037] 1) At 120°C, with Ar introduced, time-resolved XAS and MS data were recorded simultaneously to obtain relevant information.

[0038] 2) At 120°C, turn off the Ar gas and introduce CO gas while recording time-resolved XAS and MS data to obtain relevant information.

[0039] 3) At 120°C, turn off CO and introduce a mixture of CO and O2 while simultaneously recording time-resolved XAS and MS data to obtain relevant information.

[0040] 4) At 120°C, the CO and O2 mixture was turned off and O2 was introduced while simultaneously recording time-resolved XAS and MS data to obtain relevant information.

[0041] 5) Data collation: QXAFS, XANES and EXAFS data of different samples under different environments are as follows: Figure 2 As shown in the mass spectrum Figure 3 shown.

[0042] It can be seen that the time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system provided by the utility model can realize a comprehensive analysis of material structure and chemical changes, and provide strong technical support for material science and chemical research.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible to the above embodiments of the present invention. Any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention fall within the scope of protection of the present invention. Anything not fully described in this invention represents conventional technology.

Claims

1. A time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system, characterized in that: include: A light source, a fast-scan monochromator, a slit, a first ionization chamber, a sample chamber, and a second ionization chamber are sequentially arranged in the direction of X-ray propagation; a fluorescence detector or a solid-state detector is arranged perpendicular to the optical axis of the sample chamber; and a mass spectrometer is connected to the end of the sample chamber; and a data acquisition system is simultaneously connected to the first and second ionization chambers and the mass spectrometer. The data acquisition system can obtain time-resolved XAS spectrum information of the sample and MS spectrum information of real-time changes of reactants and products during the reaction process.

2. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 1, characterized in that: The system also includes a standard sample stage and a third ionization chamber, which are sequentially arranged after the second ionization chamber in the direction of X-ray propagation. The standard sample stage is used to place a standard sample. The third ionization chamber is connected to the data acquisition system to detect the X-ray absorption data of the standard sample to achieve calibration of the X-ray energy.

3. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 1, characterized in that: The sample chamber is a sealed cavity structure, and a sample holder is provided inside for placing the test sample. The sample chamber has a hole slot that can transmit X-rays, and the hole slot is sealed by a beryllium window.

4. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 3, characterized in that: The sample chamber has a heating and heat preservation function and is provided with an air inlet at the bottom. The front end of the air inlet is connected to a mass flow control system to facilitate accurate control of the gas flow.

5. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 4, characterized in that: The top of the sample chamber is connected to a three-way interface, one end of which is connected to a mass spectrometer for receiving and analyzing gas molecules in the sample chamber to detect the components of reactants and products, and the other end is connected to an exhaust port for exhausting gas.

6. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 1, characterized in that: The solid-state detector is a silicon drift detector or a 32-element germanium detector.

7. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 1, characterized in that: The position of the sample chamber can be adjusted to obtain an optimal optical signal.

8. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 3, characterized in that: When the transmission method is used, the test sample is arranged in a vertical direction in the sample chamber. When the fluorescence method is used, the test sample is arranged in the sample chamber at an angle of 45 degrees to the vertical direction.

9. The time-resolved synchrotron radiation X-ray absorption spectroscopy and mass spectrometry testing system according to claim 1, characterized in that: The fastest time resolution can reach 10 milliseconds.

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