Multifunctional catalytic characterization device and application thereof

Abstract

The invention discloses a multifunctional catalytic characterization device and application thereof.The multifunctional catalytic characterization device comprises a first six-way valve and a second six-way valve, six ports of the first six-way valve are numbered as the first port to the sixth port respectively, the first port is connected with a carrier gas source, and the third port and the sixth port are connected with a quantitative ring respectively; six ports of the second six-way valve are numbered as a port 7 to a port 12 respectively, the port 7 is connected with the port 2, the port 8 is connected with the detector, the port 9 and the port 12 are respectively connected with the reactor, the port 10 is connected with the port 5, and the port 11 is connected with the second gas source. Through cooperation of opening and closing of the two six-way valves and matching of different reactors and different detectors, multiple catalytic characterization means such as pulse titration, temperature programmed reduction / oxidation and temperature programmed desorption are achieved, and the universality is high; the gas source is integrated, the gas path is simple, the complexity of the device is reduced, the gas consumption is reduced, and the cost of the device can be greatly reduced.

Description

Technical Field

[0001] The invention relates to the technical field of catalytic characterization, and in particular to a multifunctional catalytic characterization device and application thereof. Background Art

[0002] Heterogeneous catalysis is an important part of catalytic research and is widely used in many fields such as chemical industry, energy, and environment. Taking the currently popular heterogeneous catalytic reactions such as carbon dioxide hydrogenation, ammonia synthesis, and unsaturated hydrocarbon epoxidation as examples, in order to improve the efficiency and selectivity of the reaction, researchers are committed to the screening or optimization of catalysts. Generally speaking, researchers mainly evaluate catalyst performance and explore catalytic mechanisms from the following three aspects: first, characterize the intrinsic activity of the catalyst based on the number of active sites on the catalyst surface; second: the sensitivity of the catalyst to the oxidizing / reducing atmosphere at different temperatures; third, the adsorption and desorption ability of the catalyst for reactants and products. For these three aspects, pulse titration, programmed temperature reduction / oxidation, and programmed temperature desorption are required, respectively. These technologies require different devices to achieve the desired effect, which leads to the problem of cumbersome procedures and high costs in catalytic characterization experiments. Therefore, integrating various catalytic characterization functions to simplify related equipment and achieve cost reduction and efficiency improvement is of great significance for the development of heterogeneous catalysts with superior performance.

[0003] Patent CN102359989B discloses a multifunctional catalyst reaction evaluation characterization device, which includes: a gas circuit control component, a catalytic reaction component, a detection function switching component, a signal detection processing component, and a detection gas circuit balance component. The device can integrate gas chromatography thermal conductivity detection, hydrogen flame ionization detection, and catalyst evaluation systems into one, and realize different detection methods through different combinations of solenoid valves. However, the existing characterization devices have functional limitations, as well as complex gas circuits and the resulting high gas source consumption and high costs. At the same time, the presence of residual impurities in the device can easily lead to low detection accuracy. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a multifunctional catalytic characterization device and its application. The device is configured as an independent module, which can be matched with different detectors or different characterization systems to integrate a variety of catalytic characterization technologies, simplify the device, and reduce costs; the gas source is combined, the gas path is simple, the complexity of the device is reduced, the gas source consumption is reduced, and the cost is reduced; the residual gas in the device can be removed in time to improve the accuracy of detection.

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a multifunctional catalytic characterization device, comprising a first six-way valve and a second six-way valve;

[0006] The six ports of the first six-port valve are numbered as port 1 to port 6 in a clockwise direction, wherein port 1 is connected to a carrier gas source, ports 3 and 6 are connected to a gas outlet and a gas inlet of a quantitative loop, respectively, and port 4 is connected to a gas exhaust port;

[0007] The six ports of the second six-way valve are numbered as port seven to port twelve in a clockwise direction, wherein port seven is connected to port two of the first six-way valve, port eight is connected to the air inlet end of the detector, port nine and port twelve are respectively connected to the air outlet end and the air inlet end of the reactor, port ten is connected to port five of the first six-way valve, and port eleven is connected to a second gas source, which is a pretreatment gas source and / or a pulse gas source.

[0008] The present invention is provided with two six-way valves, and through the coordination of opening and closing of the two six-way valves, different reactors and different detectors are matched to realize pulse titration, programmed temperature reduction / oxidation, programmed temperature desorption and other catalytic characterization methods, and has strong versatility.

[0009] The present invention integrates the gas source, simplifies the gas path, reduces the complexity of the device, reduces the gas consumption, and can achieve a significant reduction in device cost; the device module is arranged in the insulation module, which can promote the discharge of impurity gases and improve the accuracy of catalytic characterization.

[0010] Furthermore, when the first six-way valve is closed, port one is connected to port two, port three is connected to port four, and port five is connected to port six;

[0011] When the first six-way valve is opened, port 1 is connected to port 6, port 2 is connected to port 3, and port 4 is connected to port 5;

[0012] When the second six-way valve is closed, port seven is connected to port eight, port nine is connected to port ten, and port eleven is connected to port twelve;

[0013] When the second six-way valve is opened, port seven is connected to port twelve, port eight is connected to port nine, and port ten is connected to port eleven.

[0014] Furthermore, the reactor is a fixed bed reactor or a photothermal flow reactor.

[0015] Furthermore, the detector is a thermal conductivity detector (TCD), an infrared detector or a mass spectrometer detector.

[0016] Furthermore, it also includes a heat preservation module, in which the first six-way valve, the second six-way valve and the quantitative ring are all arranged, wherein the temperature of the heat preservation module is -20°C to 300°C.

[0017] Furthermore, flow meters are provided at the front ends of the port one and the port eleven.

[0018] Furthermore, it also includes an integrated control module for controlling the temperature of the insulation module and the reactor, the opening and closing of the first six-way valve and the second six-way valve, and the gas flow entering the port one and the port seven through the flow meter.

[0019] Furthermore, the volume of the quantitative loop is 0.1-3 mL.

[0020] Furthermore, a gas path replacement connector is provided at the front end of the detector for adapting to different detectors.

[0021] The second aspect of the present invention provides the use of the device described in the first aspect in catalytic characterization of pulse titration, programmed temperature reduction / oxidation, and programmed temperature desorption.

[0022] Beneficial effects of the present invention:

[0023] The present invention is provided with two six-way valves, and through the coordination of opening and closing of the two six-way valves, different reactors and different detectors are matched to realize pulse titration, programmed temperature reduction / oxidation, programmed temperature desorption and other catalytic characterization methods, and has strong versatility.

[0024] The present invention integrates the gas source, simplifies the gas path, reduces the complexity of the device, reduces the gas consumption, and can achieve a significant reduction in the cost of the device.

[0025] The present invention arranges the device module in the heat preservation module, which can promote the discharge of impurity gases and improve the accuracy of catalytic characterization. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic diagram of the first six-way valve and the second six-way valve of the present invention both being in a closed state;

[0028] Figure 2 It is a schematic diagram of the first six-way valve of the present invention being closed and the second six-way valve being opened;

[0029] Figure 3 It is a schematic diagram of the first six-way valve and the second six-way valve of the present invention both being in an open state;

[0030] Figure 4 This is a rendering of the pulse titration experiment characterization of Example 1 of the present invention;

[0031] Figure 5 This is a rendering of a temperature-programmed desorption characterization experiment in Example 2 of the present invention;

[0032] Figure 6 This is a rendering of the temperature-programmed reduction characterization experiment of Example 3 of the present invention;

[0033] Figure 7 This is a rendering of the light-added temperature-programmed desorption characterization experiment of Example 4 of the present invention;

[0034] Explanation of numbers in the figure: V1, first six-way valve, V2, second six-way valve, 1, port one, 2, port three, 3, port three, 4, port four, 5, port five, 6, port six, 7, port seven, 8, port eight, 9, port nine, 10, port ten, 11, port eleven, 12, port twelve, 13, carrier gas source, 14, quantitative loop, 15, second gas source, 16, reactor, 17, gas exhaust port, 18, detector, 19, insulation module, 20, gas path replacement connector, 21, integrated control module. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be described clearly and completely below in conjunction with the specific embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] refer to Figure 1-3 As shown, this embodiment provides a multifunctional catalytic characterization device, including a first six-way valve V1 and a second six-way valve V2; the six ports of the first six-way valve V1 are numbered as ports 1 to 6 in a clockwise direction, and are numbered 1 to 6 in sequence, wherein port 1 is connected to a carrier gas source 13, ports 3 and 6 are connected to an outlet end and an inlet end of a quantitative ring 14, respectively, and port 4 is connected to a gas exhaust port 17; the six ports of the second six-way valve V2 are numbered as ports 1 to 6 in a clockwise direction, and are numbered 1 to 6 in sequence, wherein port 1 is connected to a carrier gas source 13, ports 3 and 6 are connected to an outlet end and an inlet end of a quantitative ring 14, respectively, and port 4 is connected to a gas exhaust port 17; They are numbered respectively as port seven 7 to port ten 102, and are numbered 7-12 in sequence, wherein port seven 7 is connected to port two 2 of the first six-way valve V1, port eight 8 is connected to the air inlet end of the detector 18, port nine 9 and port twelve 12 are respectively connected to the air outlet end and the air inlet end of the reactor 16, port ten 10 is connected to port five 5 of the first six-way valve V1, and port eleven 11 is connected to the second gas source 15, which is a pre-treatment gas source and / or a pulse gas source.

[0037] As a specific implementation, when the first six-way valve V1 is closed, port one 1 is connected with port two 2, port three 3 is connected with port four 4, and port five 5 is connected with port six 6; when the first six-way valve V1 is opened, port one 1 is connected with port six 6, port two 2 is connected with port three 3, and port four 4 is connected with port five 5; when the second six-way valve V2 is closed, port seven 7 is connected with port eight 8, port nine 9 is connected with port ten 10, and port eleven 11 is connected with port ten-10-2; when the second six-way valve V2 is opened, port seven 7 is connected with port ten-10-2, port eight 8 is connected with port nine 9, and port ten-10 is connected with port eleven 11. Figure 1 is a schematic diagram showing that the first six-way valve V1 and the second six-way valve V2 are both in a closed state, Figure 2 It is a schematic diagram of the state where the first six-way valve V1 is closed and the second six-way valve V2 is opened; Figure 3 It is a schematic diagram showing that the first six-way valve V1 and the second six-way valve V2 are both in an open state.

[0038] As a specific implementation, the reactor 16 is a fixed bed reactor or a photothermal flow reactor; the detector 18 is a thermal conductivity detector, an infrared detector or a mass spectrometer detector; a gas path replacement connector 20 is provided at the front end of the detector 18 for adapting to different detectors 18.

[0039] Preferably, it also includes a heat preservation module 19, wherein the first six-way valve V1, the second six-way valve V2 and the quantitative ring 14 are all arranged in the heat preservation module 19, wherein the temperature of the heat preservation module 19 is -20°C to 300°C; and flow meters are arranged at the front ends of the port 11 and the port 11. It also includes a comprehensive control module 21, which is connected to the heat preservation module 19, the reactor 16, the first six-way valve V1, the second six-way valve V2 and the flow meter, and is used to control the temperature of the heat preservation module 19 and the reactor 16, the opening and closing of the first six-way valve V1 and the second six-way valve V2, and the gas flow rate entering the port 11 and the port 7 through the flow meter.

[0040] As a specific implementation, the volume of the quantitative ring 14 is 0.1-3 mL.

[0041] In this embodiment, two six-way valves are arranged. By coordinating the opening and closing of the two six-way valves, and matching different reactors 16 and different detectors 18, various catalytic characterization methods such as pulse titration, programmed temperature reduction / oxidation, and programmed temperature desorption are realized, and the versatility is strong; the gas source is integrated, the gas path is simple, the complexity of the device is reduced, and the gas consumption is reduced, which can achieve a significant reduction in the cost of the device; the device module is arranged in the insulation module 19, which can promote the discharge of impurity gases and improve the accuracy of catalytic characterization.

[0042] The following is an example of the application of the device of the above example in catalytic characterization.

[0043] Example 1

[0044] The multifunctional catalytic characterization device of the present invention is used to conduct a pulse titration experiment to explore the change in the number of active sites of the Ni / SiO2 catalyst before and after methane dry reforming, wherein the reactor 16 is a tubular fixed bed reactor, the detector 18 is replaced with an infrared detector, and the insulation module 19 is set to 120°C. The specific steps are as follows:

[0045] Step 1 (catalyst pretreatment): The first six-way valve V1 and the second six-way valve V2 are both in a closed state (e.g. Figure 1 As shown in FIG. 1 , the carrier gas source 13 and the second gas source 15 are respectively fed with Ar gas at a flow rate of 20 ml / min, and the gases enter the detector 18 and the reactor 16 respectively. The reactor 16 is heated to 300° C. at a heating rate of 10° C. / min, maintained at this temperature for 1 hour to remove impurities adsorbed on the catalyst surface, and then naturally cooled to room temperature.

[0046] Step 2 (Pre-cut valve): The first six-way valve V1 remains closed, and the second six-way valve V2 is opened (e.g. Figure 2 shown).

[0047] Step 3 (pulse gas on): switch the second gas source 15 to a mixed pulse gas of CH4 and CO2 (CH4:CO2=1:1) with a flow rate of 20 ml / min. At this time, the pulse gas passes through the six-way valve through a path of 15-11-10-5-6-14-3-4-17, and the pulse gas fills the quantitative ring 14.

[0048] Step 4 (cut valve adsorption): The first six-way valve V1 is opened, and the second six-way valve V2 remains open (such as Figure 3 As shown), keep for 0.1min and proceed to the next step. In this state, the Ar gas in the gas source 13 is instantly switched to 13-1-6-14-3-2-7-12-16-9-8-20-18 through the path, and the Ar gas pushes the pulse reaction gas in the quantitative loop 14 into the reactor 16 and finally into the detector 18. The catalyst adsorbs the reaction gas in this process.

[0049] Step 5: (Cut valve and purge): The first six-way valve V1 is closed, and the second six-way valve V2 remains open (such as Figure 2 In this state, the pulse reaction gas fills the quantitative loop 14 again, and the Ar gas passes through the reactor 16 to purge the impurity gas remaining in the reactor 16 and the pipeline.

[0050] Step 6: (Repeated pulse adsorption): Repeat Step 4 and Step 5 to perform multiple pulse adsorption operations. During each pulse process, the reaction gas signal detected by the detector 18 will gradually increase until it stabilizes, indicating that the amount of reaction gas adsorbed by the catalyst has gradually reached saturation.

[0051] Step 7 (calculation of the number of active sites): Since the volume of gas in the quantitative ring 14 is known, the amount of substance can be converted using the gas molar volume formula, and finally the amount of reaction gas adsorbed by the catalyst can be calculated using the gas consumption, thereby finally obtaining the number of active sites of the catalyst. The specific results are as follows: Figure 4 shown.

[0052] Example 2

[0053] The multifunctional catalytic characterization device of the present invention was used to conduct a temperature-programmed desorption experiment to explore the change in the CO adsorption capacity of the Ni / MgAl2O4 catalyst after high-temperature treatment, wherein the reactor 16 was a tubular fixed bed reactor and the detector 18 was replaced with a TCD detector. The insulation module 19 was set at 120°C, and the specific steps were as follows:

[0054] Step 1 (catalyst pretreatment): the same operation as Step 1 of Example 1.

[0055] Step 2 (gas adsorption): After the catalyst pretreatment is completed, the second gas source 15 is switched to CO at a flow rate of 20 ml / min and introduced into the fixed bed reactor 16. The reactor 16 is kept at room temperature for 30 minutes to allow the catalyst surface to fully adsorb CO.

[0056] Step 3 (Purge): The first six-way valve V1 remains closed, and the second six-way valve V2 is opened (such as Figure 2 As shown in the figure, the path of Ar of carrier gas source 13 in the six-way valve is changed to 13-1-2-7-12-16-9-8-18, and this state is maintained for 20 minutes to purge the CO gas in the pipeline.

[0057] Step 4 (heating desorption): After the purge is completed, the fixed bed reactor 16 is heated to 800°C at a heating rate of 10°C / min and the CO signal is collected through the detector 18 to observe the change in the CO desorption temperature on the catalyst. The final test results are as follows: Figure 5 shown.

[0058] Example 3

[0059] The multifunctional catalytic characterization device of the present invention was used to carry out a programmed temperature reduction experiment to explore the binding strength between O atoms and In atoms in In2O3 loaded on different carriers, wherein the reactor 16 was a tubular fixed bed reactor, the detector 18 was replaced with a mass spectrometer detector, and the insulation module 19 was set at 120°C. The specific steps were as follows:

[0060] Step 1 (catalyst pretreatment): the same operation as Step 1 of Example 1.

[0061] Step 2 (reducing gas introduction): After the catalyst pretreatment is completed, the second gas source 15 is switched to a H2 / Ar mixed gas with a flow rate of 20 ml / min and introduced into the reactor 16.

[0062] Step 3 (programmed temperature rise): control the reactor 16 to rise to 600°C at a heating rate of 10°C / min, collect the signal generated by H2O through a mass spectrometer, and compare the temperature of H2O generated in different catalysts to determine the bonding strength between O atoms and In atoms. The final test results are as follows: Figure 6 shown.

[0063] Example 4

[0064] The multifunctional catalytic characterization device of the present invention was used to conduct a light-induced temperature-programmed desorption experiment to explore the effect of light introduction on the catalytic activity of ethylene in LaMn 1-x Cu x The effect of adsorption strength on the O3 catalyst, wherein the reactor 16 is replaced with a photothermal flow reactor, the detector 18 is a TCD detector, and the insulation module 19 is set to 120°C. The specific steps are:

[0065] Step 1 (catalyst pretreatment): the same operation as Step 1 of Example 1.

[0066] Step 2 (gas adsorption): After the catalyst pretreatment is completed, the second gas source 15 is switched to C2H4 with a flow rate of 20 ml / min and introduced into the photothermal flow reactor 16. The reactor is kept at room temperature for 30 minutes to allow the catalyst surface to fully adsorb C2H4.

[0067] Step 3 (Purge): The first six-way valve V1 remains closed, and the second six-way valve V2 is opened (such as Figure 2 As shown in the figure, the path of Ar of carrier gas source 13 in the six-way valve is changed to 13-1-2-7-12-16-9-8-18, and this state is maintained for 20 minutes to purge the C2H4 gas in the pipeline.

[0068] Step 4 (add light): Use a xenon lamp to add 0.2W / cm -2 Irradiate the catalyst surface with light of a certain intensity and wait for the light intensity to stabilize.

[0069] Step 5 (temperature rise desorption): After the light intensity is stable, the photothermal flow reactor 16 is heated to 800°C at a rate of 10°C / min, and the CO signal is collected through the detector 18 to observe the change in the desorption temperature of C2H4 on the catalyst after light addition. The final test results are as follows: Figure 7 shown.

[0070] In summary, the present invention realizes a variety of catalytic characterization methods such as pulse titration, programmed temperature reduction / oxidation, and programmed temperature desorption by coordinating the opening and closing of two six-way valves, matching different reactors and different detectors, and has strong versatility.

[0071] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A multifunctional catalytic characterization device, characterized in that: including a first six-way valve and a second six-way valve; The six ports of the first six-port valve are numbered as port 1 to port 6 in a clockwise direction, wherein port 1 is connected to a carrier gas source, ports 3 and 6 are connected to a gas outlet and a gas inlet of a quantitative loop, respectively, and port 4 is connected to a gas exhaust port; The six ports of the second six-way valve are numbered as port seven to port twelve in a clockwise direction, wherein port seven is connected to port two of the first six-way valve, port eight is connected to the air inlet end of the detector, port nine and port twelve are respectively connected to the air outlet end and the air inlet end of the reactor, port ten is connected to port five of the first six-way valve, and port eleven is connected to a second gas source, which is a pretreatment gas source and / or a pulse gas source.

2. The multifunctional catalytic characterization device according to claim 1, characterized in that: When the first six-way valve is closed, port one is connected to port two, port three is connected to port four, and port five is connected to port six; When the first six-way valve is opened, port 1 is connected to port 6, port 2 is connected to port 3, and port 4 is connected to port 5; When the second six-way valve is closed, port seven is connected to port eight, port nine is connected to port ten, and port eleven is connected to port twelve; When the second six-way valve is opened, port seven is connected to port twelve, port eight is connected to port nine, and port ten is connected to port eleven.

3. The multifunctional catalytic characterization device according to claim 1, characterized in that: The reactor is a fixed bed reactor or a photothermal flow reactor.

4. The multifunctional catalytic characterization device according to claim 1, characterized in that: The detector is a thermal conductivity detector, an infrared detector or a mass spectrometer detector.

5. The multifunctional catalytic characterization device according to claim 1, characterized in that: It also includes a heat preservation module, in which the first six-way valve, the second six-way valve, the quantitative ring and its connecting gas path are all arranged, wherein the temperature of the heat preservation module is -20°C to 300°C.

6. The multifunctional catalytic characterization device according to claim 5, characterized in that: Flow meters are arranged at the front ends of the passage 1 and the passage 11.

7. The multifunctional catalytic characterization device according to claim 6, characterized in that: It also includes an integrated control module for controlling the temperature of the insulation module and the reactor, the opening and closing of the first six-way valve and the second six-way valve, and the gas flow entering port one and port seven through a flow meter.

8. The multifunctional catalytic characterization device according to claim 1, characterized in that: The volume of the quantitative loop is 0.1-3 mL.

9. The multifunctional catalytic characterization device according to claim 1, characterized in that: A gas path replacement joint is arranged at the front end of the detector for adapting to different detectors.

10. Use of the device according to any one of claims 1 to 9 in catalytic characterization of pulse titration, temperature-programmed reduction / oxidation, and temperature-programmed desorption.

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