Method for detecting deuterium after water-hydrogen isotope liquid phase catalytic exchange

Abstract

This invention discloses a method for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange. The apparatus used in this method includes a first Erlenmeyer flask, a metering pump, a catalytic exchange bed, a flow meter, and a time-of-flight mass spectrometer. The detection process is as follows: a mixture of heavy water and purified water is filled into the first Erlenmeyer flask; a hydrophobic catalyst and hydrophilic filler for the isotope exchange reaction are filled into the catalytic exchange bed; the mixed water enters the catalytic exchange bed from the top and undergoes an isotope exchange reaction with hydrogen gas entering from the bottom of the bed; the deuteride gas after the exchange reaction is directly introduced into the time-of-flight mass spectrometer for detection via the flow meter. This method can monitor the changing trend of deuteride gas after water-hydrogen isotope liquid-phase catalytic exchange online. Simultaneously, the performance of the catalyst, the packing ratio, and the packing method can be examined, thereby further guiding the process. This method features fast analysis speed and high sensitivity.

Description

Technical Field

[0001] This invention patent is mainly used for the detection of hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange. Specifically, it utilizes time-of-flight mass spectrometry to monitor the changing trend of hydrogen deuteride in real time and to examine the maximum exchange efficiency under different flow rates, temperatures, and pressures. It features fast detection speed and high accuracy. Background Technology

[0002] Time-of-flight mass spectrometry (TOF-MS) offers numerous advantages and plays a vital role in many fields. First, it boasts a wide mass range, theoretically with no upper limit on mass-to-charge ratio. Second, it exhibits excellent resolution, accurately distinguishing ions with extremely similar mass-to-charge ratios, which aids in the accurate determination of compound molecular weights. Furthermore, it requires small sample volumes and offers high sensitivity, making it particularly advantageous for the analysis of trace or micro-samples. In the study of water-hydrogen isotope liquid-phase catalytic exchange processes, the optimal exchange efficiency can be obtained by examining parameters such as gas flow rate, temperature, and pressure.

[0003] A simple, rapid, and accurate method for measuring hydrogen deuteride was established using time-of-flight mass spectrometry (TOF-MS) with a direct sample introduction approach. This method is used to investigate the exchange efficiency of catalysts. By analyzing the trends in hydrogen deuteride concentrations, the process can be better guided, and costs can be reduced. Summary of the Invention

[0004] The purpose of this invention is to provide a method for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange. Specifically, it involves using a time-of-flight mass spectrometer to monitor the changing trend of hydrogen deuteride in real time.

[0005] To achieve the above objectives, the technical solution adopted in this invention application is as follows:

[0006] A method for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange, the apparatus of which includes a first triangular flask 1, a metering pump 2, a catalytic exchange bed 3, a flow meter 4, a time-of-flight mass spectrometer 5, and a second triangular flask 6; the mouth of the first triangular flask 1 is provided with a sealing rubber stopper, on which a gas inlet and a liquid outlet are provided, and the liquid outlet is connected to the liquid inlet at the top of the catalytic exchange bed 3 through a metering pump 2 provided on a connecting pipeline;

[0007] The catalytic exchange bed 3 is a closed cavity with a liquid inlet and a hydrogen deuteride outlet at the top. The liquid inlet is connected to the liquid outlet of the first triangular flask 1 via a connecting pipe, and the hydrogen deuteride outlet is connected to the sample inlet of the time-of-flight mass spectrometer 5 via a flow meter 4 installed on the connecting pipe.

[0008] The bottom of the catalytic exchange bed 3 is provided with a hydrogen inlet and a liquid outlet. The hydrogen inlet is connected to a pure hydrogen gas source, and the liquid outlet is connected to a second triangular flask 6. The second triangular flask 6 collects the mixed water after the reaction.

[0009] The detection process is as follows: a mixture of heavy water and pure water is filled into the first triangular flask 1, and a hydrophobic catalyst and hydrophilic filler for isotope exchange reaction are filled into the catalytic exchange bed 3. The flow rates of the metering pump 2 and the flow meter 4, as well as the injection flow rate of hydrogen gas at the bottom, are set. The metering pump is started, and the mixed water in the first triangular flask 1 enters the catalytic exchange bed 3 from the top, where it undergoes an isotope exchange reaction with the hydrogen gas entering from the bottom of the catalytic exchange bed 3. The gas discharged after the exchange reaction is directly introduced into the ionization region of the time-of-flight mass spectrometer 5 through the flow meter 4 for ionization and detection. The time-of-flight mass spectrometer operates in continuous monitoring mode, which can monitor the changing trend of deuterated hydrogen gas generated after water-hydrogen isotope liquid-phase catalytic exchange in real time.

[0010] The volume ratio of heavy water to pure water in the mixed water in the first triangular flask 1 is 1:80-120. The flow rate of the metering pump 2 is 1-10 ml / min. The mixed water in the first triangular flask 1 enters the catalytic reaction bed 3 from the top through the metering pump 2.

[0011] Pure hydrogen enters from the hydrogen inlet at the bottom of the catalytic exchange bed 3 and undergoes isotope exchange reaction with the mixed water entering from the top through the catalytic reaction bed 3. The exchanged hydrogen deuteride gas enters the time-of-flight mass spectrometer 5 through the flow meter 4 for detection. The injection flow rate of pure hydrogen is 400-600 ml / min, preferably 500 ml / min.

[0012] The temperature for isotope exchange reaction is 80-120℃ (preferably 90-110℃, more preferably 100℃).

[0013] The mass ratio of hydrophilic packing material to hydrophobic catalyst inside the catalytic exchange bed 3 is 3-5:1. The hydrophobic catalyst is a Pt-based catalyst supported on polystyrene-divinylbenzene resin (Pt / SDB catalyst), wherein the mass loading of the noble metal Pt is 1% to 10%. The hydrophilic packing material is stainless steel triangular spring packing material.

[0014] The hydrophilic filler and hydrophobic catalyst are packed in a layered and orderly manner in the catalytic exchange bed 3. First, half of the required hydrophilic filler is packed at the bottom of the catalytic exchange bed according to the ratio. Then, the required hydrophobic catalyst is packed in the ratio. Finally, the other half of the required hydrophilic filler is packed in the ratio.

[0015] The second triangular flask 6 connected to the bottom of the catalytic reaction bed 3 is used for collecting the mixed water after the isotope exchange reaction.

[0016] The detection method disclosed in this invention application can monitor the change trend of hydrogen deuteride gas after water-hydrogen isotope liquid-phase catalytic exchange online. It can be used to investigate different conditions such as raw material flow rate, reaction temperature and catalyst loading ratio. It has the advantages of simple structure, high sensitivity and fast response speed. Attached Figure Description

[0017] Figure 1 A schematic diagram of an instrument for detecting hydrogen deuteride after liquid-phase catalytic exchange of water-hydrogen isotopes; 1—first triangular flask, 2—metering pump, 3—catalytic exchange bed, 4—flow meter, 5—time-of-flight mass spectrometer, 6—second triangular flask.

[0018] Figure 2 The image shows the detection results of hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange in Example 1. Detailed Implementation

[0019] This invention patent provides a method for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange, such as... Figure 1 As shown, the apparatus used in this method includes a first triangular flask 1, a metering pump 2, a catalytic exchange bed 3, a flow meter 4, a time-of-flight mass spectrometer 5, and a second triangular flask 6. The mouth of the first triangular flask 1 is provided with a sealing rubber stopper, and the sealing rubber stopper is provided with an air inlet and a liquid outlet. The liquid outlet is connected to the liquid inlet at the top of the catalytic exchange bed 3 through the metering pump 2 provided on the connecting pipeline.

[0020] The catalytic exchange bed 3 is a closed cavity with a liquid inlet and a hydrogen deuteride outlet at the top. The liquid inlet is connected to the liquid outlet of the first triangular flask 1 via a connecting pipe, and the hydrogen deuteride outlet is connected to the sample inlet of the time-of-flight mass spectrometer 5 via a flow meter 4 installed on the connecting pipe.

[0021] The bottom of the catalytic exchange bed 3 is provided with a hydrogen inlet and a liquid outlet. The hydrogen inlet is connected to a pure hydrogen gas source, and the liquid outlet is connected to a second triangular flask 6, which collects the mixed water after the reaction.

[0022] The specific process for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange using the above-mentioned device is as follows: A mixture of heavy water and pure water is filled into the first triangular flask 1 by volume. A hydrophobic catalyst (Pt-SDB catalyst) and hydrophilic packing material (stainless steel triangular spring packing material) for isotope exchange reaction are filled into the catalytic exchange bed 3 by volume. The flow rates of the metering pump 2 and the flow meter 4, as well as the injection flow rate of hydrogen gas at the bottom, are set. The metering pump is started, and the mixed water in the first triangular flask 1 enters the catalytic exchange bed 3 from the top of the catalytic exchange bed 3. It undergoes an isotope exchange reaction with the hydrogen gas entering from the bottom of the catalytic exchange bed 3. The deuteride gas after the exchange reaction enters the time-of-flight mass spectrometer 5 through the flow meter 4 for detection.

[0023] Example 1

[0024] A mixture of heavy water and purified water (100 ml heavy water and 1000 ml purified water) was placed in the first triangular flask 1. A Pt-SDB catalyst (manufactured by Shanghai Maclean Biochemical Technology Co., Ltd.) with a Pt mass content of 1% was packed into the catalytic exchange bed 3, along with stainless steel triangular spring packing. The stainless steel triangular spring packing had dimensions of 2 mm × 2 mm × 0.2 mm (side length × height × thickness) and a specific surface area of ​​3800 m². -1 The porosity is 0.8, the bulk density is 1.5 kg / L, the theoretical number of plates is 80 / m, the mass ratio of stainless steel triangular spring packing to 1% Pt-SDB catalyst is 4:1, and the loading sequence of catalyst and packing in catalytic exchange bed 3 is as follows: first, 200g of stainless steel triangular spring packing is loaded, and then 100g of catalyst is loaded on top of the stainless steel triangular spring packing. The catalyst, containing 1% Pt by mass, was topped with 200g of stainless steel triangular spring packing material, bringing the total height of the catalyst and packing material in the catalytic exchange bed 3 to 10cm. The metering pump 2 was set to a flow rate of 10ml / min, the bottom hydrogen injection rate to 500ml / min, and the flow meter 4 to a flow rate of 100ml / min. The metering pump was started, and the mixed water in the first triangular flask 1 entered the catalytic exchange bed 3 from the top, where it underwent an isotope exchange reaction with the hydrogen entering from the bottom. The reaction temperature in the catalytic exchange bed 3 was 100℃. The deuterated hydrogen gas after the exchange reaction was detected by the time-of-flight mass spectrometer 5 via the flow meter 4. The time-of-flight mass spectrometer has a photoelectron efficiency of 22eV, and the cumulative acquisition time was 5s. The detected structure is shown below. Figure 2 As shown, the changing trend of HD can be clearly detected.

Claims

1. A method for detecting hydrogen deuteride after water-hydrogen isotope liquid-phase catalytic exchange, characterized in that: The apparatus used in this method includes a first triangular flask (1), a metering pump (2), a catalytic exchange bed (3), a flow meter (4), a time-of-flight mass spectrometer (5), and a second triangular flask (6). The mouth of the first triangular flask (1) is provided with a sealing rubber stopper, and the sealing rubber stopper is provided with an air inlet and a liquid outlet. The liquid outlet is connected to the liquid inlet at the top of the catalytic exchange bed (3) through the metering pump (2) provided on the connecting pipeline. The catalytic exchange bed (3) is a closed cavity with a liquid inlet and a hydrogen deuteride outlet at the top. The liquid inlet is connected to the liquid outlet of the first triangular flask (1) through a connecting pipe, and the hydrogen deuteride outlet is connected to the sample inlet of the time-of-flight mass spectrometer (5) through a flow meter (4) installed on the connecting pipe. The bottom of the catalytic exchange bed (3) is provided with a hydrogen inlet and a liquid outlet. The hydrogen inlet is connected to a pure hydrogen gas source, and the liquid outlet is connected to a second triangular flask (6). The second triangular flask (6) collects the mixed water after the reaction. The detection process is as follows: a mixture of heavy water and pure water is filled into the first triangular flask (1), and a hydrophobic catalyst and hydrophilic filler for isotope exchange reaction are filled into the catalytic exchange bed (3). The flow rates of the metering pump (2) and the flow meter (4) and the injection flow rate of hydrogen at the bottom are set. The metering pump is started, and the mixed water in the first triangular flask (1) enters the catalytic reaction bed (3) from the top. It undergoes isotope exchange reaction with the hydrogen entering from the bottom of the catalytic exchange bed (3). The deuterated hydrogen gas after the exchange reaction is directly introduced into the ionization region of the time-of-flight mass spectrometer (5) through the flow meter (4) for ionization and detection. The instrument works in continuous monitoring mode and can monitor the changing trend of deuterated hydrogen gas generated after water-hydrogen isotope liquid-phase catalytic exchange in real time.

2. The detection method according to claim 1, characterized in that: The volume ratio of heavy water to pure water in the mixed water in the first triangular flask (1) is 1:80-120. The flow rate of the metering pump (2) is 1-10 mL / min. The mixed water in the first triangular flask (1) enters the catalytic reaction bed (3) from the top through the metering pump (2).

3. The detection method according to claim 1, characterized in that: Pure hydrogen enters from the hydrogen inlet at the bottom of the catalytic exchange bed (3) and undergoes isotope exchange reaction with the mixed water entering from the top through the catalytic reaction bed (3). The deuterated hydrogen gas after exchange enters the time-of-flight mass spectrometer (5) through the flow meter (4) for detection. The injection flow rate of pure hydrogen is 400-600 mL / min, preferably 500 mL / min. The temperature for isotope exchange reaction is 80-120℃ (preferably 90-110℃, more preferably 100℃).

4. The detection method according to claim 1, characterized in that: The mass ratio of the hydrophilic packing material to the hydrophobic catalyst inside the catalytic exchange bed (3) is 3-5:

1. The hydrophobic catalyst is a Pt-based catalyst supported on polystyrene-divinylbenzene resin (Pt / SDB catalyst), wherein the loading of the noble metal Pt is 1% to 10%, and the hydrophilic packing material is a stainless steel triangular spring packing material.

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