An in-situ detection device for high temperature electrocatalytic reaction gas phase intermediates

Abstract

The application relates to an in-situ detection device for high-temperature electro-catalytic reaction gas-phase intermediate products, which comprises a high-temperature electro-catalytic reactor, an ionization chamber and a mass spectrometer connected in sequence, wherein the high-temperature electro-catalytic reactor comprises a reactor cavity and a quartz tube reactor; the reactor cavity comprises a flange cavity, a fixing frame and a terminal water cooling tank connected in sequence from top to bottom; a first circulating water channel is arranged in the cavity wall of the flange cavity; and a second circulating water channel is arranged in the cylinder wall of the terminal water cooling tank; the quartz tube reactor comprises a quartz sleeve, an inner sleeve and a center ceramic tube coaxially arranged and sequentially sleeved from outside to inside; an electrode sheet is arranged between the annular protrusion in the quartz sleeve and the gap formed at the front end of the inner sleeve; a first conductive gold wire is led out from the upper surface of the electrode sheet; and a second conductive gold wire is led out from the lower surface of the electrode sheet. The application can study the direct conversion process of electric energy and chemical energy of a solid-state oxidation electrolytic cell under high-temperature conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalysis technology, in particular to an in-situ detection device for gaseous intermediates in high-temperature electrocatalytic reaction. BACKGROUND

[0002] Catalysis technology is an important industrial application technology in modern chemical production. Traditional catalysis, new catalysis such as electrocatalysis, photocatalysis and magnetic catalysis, etc. greatly reduce the production difficulty and improve the production efficiency, which is conducive to energy saving and environmental protection. In recent years, solid oxide electrolysis cells realize the direct conversion of electrical energy and chemical energy at high temperature with high efficiency and cleanness. High-temperature electrochemical reaction involves electron (charge) and ion (material) transfer on the solid / gas interface, the reaction path is complex, and the reaction mechanism is difficult to analyze. At present, through the in-situ real-time online qualitative and quantitative detection of intermediates, especially free radicals, the microstructure information of intermediates is analyzed, which provides the most direct observation data and structure information for in-depth exploration of the molecular mechanism of the microcosmic level of the catalytic reaction mechanism and reveals the dynamic evolution process and key mechanism of the catalytic reaction kinetics. The synchrotron radiation photoionization mass spectrometry technology is a mass spectrometry detection and analysis means based on ultrasonic molecular beam sampling, which has been widely used in catalysis research system.

[0003] A Chinese invention patent discloses an in-situ detection device for gaseous intermediates in catalytic reaction with different diffusion distances, which is based on synchrotron radiation photoionization mass spectrometry technology and adopts a tubular heating mode to realize in-situ detection of gaseous intermediates at different diffusion heights from the surface of the catalyst. However, due to the particularity of the solid oxide electrolysis cell research system, in-situ detection needs to be realized under the conditions of meeting higher temperature and vacuum isolation of both ends of the electrode sheet. In the research of high-temperature electrocatalytic reaction, the existing device has the following defects: (1) the temperature range of the reactor is room temperature to 600 DEG C, which cannot meet the demand of high-temperature electrocatalytic reaction (generally at 800 DEG C to 900 DEG C); (2) the ends of the electrode sheet cannot be isolated. SUMMARY

[0004] The purpose of the present application is to provide an in-situ detection device for gaseous intermediates in high-temperature electrocatalytic reaction, so as to study the process of direct conversion of electrical energy and chemical energy of solid oxide electrolysis cell under high-temperature conditions.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: comprising a high-temperature electrocatalytic reactor, an ionization chamber and a mass spectrometer connected in sequence, the high-temperature electrocatalytic reactor comprises a reactor cavity and a quartz tube reactor.

[0006] The reactor cavity comprises a flange cavity, a fixing frame and an end water cooling tank connected in sequence from top to bottom, one end of the flange cavity is connected with the ionization chamber through a fluorine rubber sealing O-ring, the other end of the flange cavity is connected with the quartz sleeve in the quartz tube reactor, the inner cavity of the flange cavity is a beam source chamber, the beam source chamber and the internal space of the quartz tube reactor axially penetrating constitute a reaction chamber, the flange cavity is provided with a vacuum extraction port, a vacuum gauge interface, an air inlet and an experimental gold wire inlet which are communicated with the beam source chamber, the cavity wall of the flange cavity is internally provided with a first circulating water channel, and the flange cavity is further provided with a first water inlet pipe and a first water outlet pipe which are connected with both ends of the first circulating water channel respectively;

[0007] The reactor cavity further comprises a threaded pipe type heating pipe composed of a spring heating ring and a mullite heat insulation pad, the threaded pipe type heating pipe is arranged in the fixing frame and coaxially sleeved on the quartz tube reactor, the fixing frame is hollow, and the fixing frame is fixed on the lower end of the flange cavity through bolts, and the mullite heat insulation pad is located between the spring heating ring and the end water cooling tank.

[0008] The end water cooling tank is in a whole cylindrical shape, the flange surface at the upper end of the end water cooling tank is connected to the lower end surface of the fixing frame through bolts, the end water cooling tank is coaxially sleeved on the quartz tube reactor, and the inner wall of the cylinder wall of the end water cooling tank is provided with a second circulating water channel, and the second circulating water channel is connected with a second water inlet pipe and a second water outlet pipe at both ends respectively.

[0009] The quartz tube reactor comprises a quartz sleeve, an inner sleeve and a center ceramic tube which are coaxially arranged and are sleeved in sequence from outside to inside, the inner sleeve comprises an inner sleeve body and a connecting pipe arranged at the lower end of the inner sleeve body, one end of the connecting pipe is connected with the bottom end of the quartz sleeve through a conversion joint, the other end of the connecting pipe is connected with a first interface of a three-way joint arranged on the center ceramic tube, the first interface and the second interface of the three-way joint are coaxially arranged, and the center ceramic tube penetrates through the first interface and the second interface, the third interface of the three-way joint is an air extraction port, and the lower end of the center ceramic tube is connected with a gas path interface of a gas flow controller.

[0010] The electrode sheet is arranged between the annular protrusion in the quartz sleeve and the gap formed at the front end of the inner sleeve, the first conductive gold wire led out of the upper surface of the electrode sheet is led out of the external power supply through the experimental gold wire inlet, and the second conductive gold wire led out of the lower surface of the electrode sheet is led out of the external power supply through the inner sleeve and finally from the third interface.

[0011] The flange cavity is sealed with the quartz sleeve, and one end of the flange cavity is provided with a flange opening matched with the quartz sleeve; the quartz sleeve is provided with a disc-shaped body matched with the flange opening at an upper position in the circumferential direction; the upper and lower end faces of the disc-shaped body are respectively provided with an upper silica gel gasket and a lower silica gel gasket; the upper silica gel gasket, the disc-shaped body and the lower silica gel gasket are arranged in the flange opening and are fixed and sealed with the flange cavity through a flange opening cover plate.

[0012] The ionization chamber is fixed with a sampling cone, the sampling cone is located in the beam source chamber, the sampling cone is coaxially arranged with the electrode sheet, and the nozzle tip of the sampling cone is opposite to the center point of the electrode sheet, and the distance between the nozzle tip of the sampling cone and the center point of the electrode sheet is adjustable within 1-50mm.

[0013] The electrode sheet is a circular sheet of solid material formed by sintering different materials, and the diameter of the electrode sheet is between 6.5-7mm, and the anode of the electrode sheet faces the nozzle tip of the sampling cone.

[0014] The outer diameter of the electrode sheet is smaller than the inner diameter of the quartz sleeve, and larger than the inner diameter of the annular protrusion inside the quartz sleeve and the outer diameter of the inner sleeve.

[0015] The end water cooling tank and the quartz sleeve are provided with a fluorine rubber sealing ring and a fluorine rubber radial sealing O-ring.

[0016] The vacuum degree in the beam source chamber is 1-10Torr, and the vacuum in the ionization chamber is 0.01-0.05Pa.

[0017] The beneficial effects of the present application are:

[0018] (1) Due to the need to maintain vacuum, the sealing method of the reactor cavity mainly adopts O-ring sealing, which cannot withstand high temperature, the present application constructs a water cooling system at both ends of the reactor cavity, uses water cooling to protect the sealing effect of the sealing surface, improves the upper limit of the temperature zone of the reactor cavity, and can improve the high temperature limit value of the reactor cavity from 600 DEG C to 900 DEG C.

[0019] (2) Because the two ends of the electrode sheet are usually passed through explosive gas, the reactor through which the two ends of the electrode sheet cannot be mixed, the present application fills non-metallic solder between the electrode sheet and the quartz reactor, and realizes the vacuum isolation of the two sides of the electrode sheet by soldering, which provides technical support for the high-temperature electro-catalytic mass spectrometry device.

[0020] (3) The inner ring clamping sleeve structure and the non-metallic soldering process are adopted to realize the vacuum isolation and positioning of the two sides of the electrode sheet.

[0021] (4) The quartz sleeve, inner sleeve and central ceramic tube are connected to each other in a sealed manner by conversion joints and tee joints. Under the premise of ensuring the sealing effect, the experimental requirement of directly blowing the electrode surface with air at the lower end and then drawing it away through the air extraction port is realized. At the same time, it provides a route from the inner cavity to the outer space for the conductive gold wire. In addition, it is easy to disassemble and can be reused by simply replacing the electrode.

[0022] (5) The position of the annular protrusion inside the quartz sleeve can be used to adjust the distance between the electrode plate and the sampling cone. The distance can be controlled from 1 mm to 50 mm so as to detect the product changes at different distances from the electrode plate.

[0023] (6) The electrode sheet is led from the vacuum to the atmospheric environment through two conductive gold wires, connecting the electrode sheet to the external power supply. By controlling the current intensity of the external power supply, the reaction degree can be effectively regulated in situ to observe the trend change of the current on the product evolution, thus realizing the in situ detection of vacuum electrocatalysis. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention. Figure 1 .

[0025] Figure 2 This is a schematic diagram of the overall structure of the present invention. Figure 2 .

[0026] Figure 3 This is a front view of the high-temperature electrocatalytic reactor of the present invention.

[0027] Figure 4 yes Figure 3 AA sectional view.

[0028] Figure 5 This is a schematic diagram of the three-dimensional structure of the reactor cavity of the present invention. Figure 1 .

[0029] Figure 6 This is a schematic diagram of the three-dimensional structure of the reactor cavity of the present invention. Figure 2 .

[0030] Figure 7 This is a left view of the reactor cavity of the present invention.

[0031] Figure 8 yes Figure 7 BB cross-sectional view.

[0032] Figure 9 This is an exploded structural diagram of the reactor cavity of the present invention.

[0033] Figure 10 This is a three-dimensional structural diagram of the flange cavity of the present invention.

[0034] Figure 11 is a plan view of the flange cavity of the present application.

[0035] Figure 12 is a C-C sectional view of Figure 11

[0036] Figure 13 is a plan view of the end water cooling tank of the present application.

[0037] Figure 14 is a D-D sectional view of Figure 13

[0038] Figure 15 is an internal circulation water channel diagram of the end water cooling tank of the present application.

[0039] Figure 16 is a structural schematic diagram of the threaded pipe type heating pipe of the present application.

[0040] Figure 17 is a three-dimensional structural schematic diagram of the quartz tube reactor of the present application.

[0041] Figure 18 is a front view of the quartz tube reactor of the present application.

[0042] Figure 19 is an E-E sectional view of Figure 18

[0043] Figure 20 is a F part enlarged view of Figure 19

[0044] Figure 21 is an exploded structural schematic diagram of the quartz tube reactor of the present application.

[0045] Figure 22 is a structural schematic diagram of the inner sleeve of the present application.

[0046] Figure 23 is a G part enlarged view of Figure 22

[0047] Figure 24 is a connection trend diagram of the first conductive gold wire of the present application.

[0048] Figure 25 is a connection trend diagram of the second conductive gold wire of the present application.

[0049] Figure 26 is a mass spectrum diagram of the key intermediate product methyl radical (CH3*) under high temperature electrocatalytic conditions in a solid oxide electrolysis cell research system obtained by using the device of the present application, which changes with current intensity.

[0050] Figure 27 ​​​​​A graph showing the change of methyl radical (CH3*) with current intensity under high-temperature electrocatalysis condition in a solid oxide electrolysis cell research system is obtained by using the device.

[0051] The marks in the above figures are as follows: reactor cavity 1, flange cavity 11, vacuum extraction port 111, vacuum gauge interface 112, gas inlet port 113, experimental gold wire inlet port 114, first circulating water channel 115, first water inlet pipe 116, first water outlet pipe 117, flange port 118, fixing frame 12, terminal water cooling tank 13, second circulating water channel 131, second water inlet pipe 132, second water outlet pipe 133, fluororubber sealing compression ring 134, fluororubber radial sealing O-ring 135, fluororubber sealing O-ring 14, beam source chamber 15, threaded tube type heating pipe 16, spring heating ring 161, mullite heat insulation pad block 162, flange port cover plate 17, quartz tube reactor 2, quartz sleeve 21, annular protrusion 211, disc body 212, inner sleeve 22, inner sleeve body 221, connecting pipe 222, central ceramic tube 23, conversion joint 24, three-way joint 25, first interface 251, second interface 252, third interface 253, electrode sheet 26, first conductive gold wire 261, second conductive gold wire 262, upper silica gel gasket 27, lower silica gel gasket 28, high-temperature electrocatalysis reactor 3, ionization chamber 4, sampling cone 41, mass spectrometer 5. DETAILED DESCRIPTION

[0052] The application will be further described below in combination with the drawings:

[0053] As shown in Figure 1 , Figure 2 An in-situ detection device for gaseous intermediate products in high-temperature electrocatalysis reaction is shown in the drawings, which comprises a high-temperature electrocatalysis reactor 3, an ionization chamber 4 and a mass spectrometer 5 connected in sequence. Further, the high-temperature electrocatalysis reactor 3 comprises a reactor cavity 1 and a quartz tube reactor 2.

[0054] Further, as shown in Figures 3-12 , the reactor cavity 1 comprises a flange cavity 11, a fixing frame 12 and a terminal water cooling tank 13 connected in sequence from top to bottom. An end of the flange cavity 11 in the axial direction is sealingly connected with the ionization chamber 4 through a fluororubber sealing O-ring 14, and the other end of the flange cavity 11 in the axial direction is sealingly connected with a quartz sleeve 21 in the quartz tube reactor 2. Specifically, the end of the flange cavity 11 sealingly matched with the quartz sleeve 21 is provided with a flange port 118 matched with the quartz sleeve 21, and the quartz sleeve 21 is provided with a disc body 212 matched with the flange port 118 at a position close to the top thereof in the circumferential direction. The disc body 212 is provided with an upper silica gel gasket 27 and a lower silica gel gasket 28 at the upper and lower end faces thereof respectively, and the upper silica gel gasket 27, the disc body 212 and the lower silica gel gasket 28 are arranged in the flange port 118 and sealingly fixed with the flange cavity 11 through a flange port cover plate 17.

[0055] Further, the inner cavity of the flange cavity 11 is the beam source chamber 15, and the beam source chamber 15 and the internal space of the quartz tube reactor 2 axially through constitute a reaction chamber, the flange cavity 11 is provided with a vacuum port 111, a vacuum gauge interface 112, an air inlet 113 and an experimental gold wire inlet 114 which are communicated with the beam source chamber 15, and the inner wall of the cavity of the flange cavity 11 is provided with a first circulating water channel 115, and the flange cavity 11 is further provided with a first water inlet pipe 116 and a first water outlet pipe 117 which are respectively connected to the two ends of the first circulating water channel 115. Preferably, the vacuum port 111 and the vacuum gauge interface 112 are CF flange interfaces, the vacuum port 111 is connected with a vacuum pump, and the vacuum gauge interface 112 is connected with a vacuum gauge. The vacuum port 111 and the vacuum gauge interface 112 are provided to meet the needs of maintaining the internal pressure state of the reactor and the access of the vacuum gauge.

[0056] Further, as shown in Figure 16 , the reactor cavity 1 further includes a threaded tube type heating pipe 16 composed of a spring heating ring 161 and a mullite heat insulation pad 162. The threaded type heating pipe 16 is placed in the fixed frame 12 and coaxially sleeved on the quartz tube reactor 2, the fixed frame 12 is hollow, and the fixed frame 12 is fixed at the lower end of the flange cavity 11 by bolts. The mullite heat insulation pad 162 is located between the spring heating ring 161 and the terminal water cooling tank 13, that is, the annular mullite heat insulation pad 162 is used to separate the terminal water cooling tank 13 and the spring heating ring 161 to prevent heat conduction to the terminal water cooling tank 13. The spring heating ring 161 is internally provided with a heating wire and a thermocouple component, and is externally connected with a temperature controller device, which can meet the needs of different temperatures in research. Since the conversion joint 24 is connected with the inner sleeve pipe 22 and the quartz sleeve pipe 21 by the O-ring and the sleeve joint, the normal working temperature range of the O-ring is below 300°C, and the mullite heat insulation pad 162 and the second circulating water channel 131 can prevent heat conduction from the spring heating ring 161 to the conversion joint 24.

[0057] Further, as shown in Figure 13 , Figure 14 , Figure 15 , the terminal water cooling tank 13 is in the shape of a cylinder as a whole, the flange face at the upper end thereof is connected to the lower end face of the fixed frame 12 by bolts, the terminal water cooling tank 13 is coaxially sleeved on the quartz tube reactor 2, and the inner wall of the cylinder of the terminal water cooling tank 13 is provided with a second circulating water channel 131, and the two ends of the second circulating water channel 131 are respectively connected with a second water inlet pipe 132 and a second water outlet pipe 133. That is, the entire reactor cavity 1 is provided with the first circulating water channel 115 and the second circulating water channel 131, and the two circulating water channels are connected with a circulating water system to build a water cooling system, and the water flow can take away the excess heat conducted to the upper and lower parts of the reactor cavity 1.

[0058] Further, the end water cooling tank 13 and the quartz sleeve 21 are provided with a fluorine rubber sealing compression ring 134 and a fluorine rubber radial sealing O-ring 135. The fluorine rubber sealing compression ring 134 and the fluorine rubber radial sealing O-ring 135 are used to fix the quartz tube reactor 2 and the fixing frame 12, because the quartz sleeve 21 is fragile, the rubber ring can play a protective role.

[0059] Further, as shown in Figures 17-23 the quartz tube reactor 2 includes the quartz sleeve 21, the inner sleeve 22 and the center ceramic tube 23 which are coaxially arranged and sequentially sleeved from outside to inside. The inner sleeve 22 includes an inner sleeve body 221 and a connecting pipe 222 arranged at the lower end of the inner sleeve body 221. One end of the connecting pipe 222 is sealingly connected with the bottom end of the quartz sleeve 21 through a conversion joint 24, and the conversion joint 24 is sealingly connected with the quartz sleeve 21 and the connecting pipe 222 through O-rings. The other end of the connecting pipe 222 is sealingly connected with a first interface 251 of a three-way joint 25 arranged on the center ceramic tube 23. The first interface 251 and a second interface 252 of the three-way joint 25 are coaxially arranged, and the center ceramic tube 23 penetrates through the first interface 251 and the second interface 252. A third interface 253 of the three-way joint 25 is an air outlet, and the lower end of the center ceramic tube 23 is connected with a gas path interface of a gas flow controller. The sealing modes between the second interface 252 and the center ceramic tube 23 and between the third interface 253 and an air outlet pipe are both radial O-ring sealing. That is, the inner sleeve 22 connects the quartz sleeve 21 through the conversion joint 24, and connects the center ceramic tube 23 through the three-way joint 25. The sealing mode is radial O-ring sealing, and the inner sleeve functions to connect the entire quartz tube reactor 2 and ensure the sealing effect of the internal space.

[0060] Further, as shown in Figure 24 , Figure 25 the annular protrusion 211 inside the quartz sleeve 21 and the gap formed at the front end of the inner sleeve 22 are provided with an electrode sheet 26. A first conductive gold wire 261 led out from the upper surface of the electrode sheet 26 is led out to an external power source through the experimental gold wire inlet 114, and a second conductive gold wire 262 led out from the lower surface of the electrode sheet 26 passes through the inner sleeve 22 and is finally led out to the external power source from the third interface 253. During operation, the electrode sheet 26 with different conductive material coatings can be matched according to actual needs.

[0061] Further, the outer diameter of the electrode sheet 26 is smaller than the inner diameter of the quartz sleeve 21, and is larger than the inner diameter of the inner annular protrusion 211 of the quartz sleeve 21 and the outer diameter of the inner sleeve 22, so as to be fixed by the inner annular protrusion 211 of the quartz sleeve 21 clamping the electrode sheet 26. That is, the electrode sheet 26 is clamped by the inner annular protrusion 211 of the quartz sleeve 21 and the front end of the inner sleeve 22, so as to be stably placed between the inner annular protrusion 211 of the quartz sleeve 21 and the front end of the inner sleeve 22. In the present application, the electrode sheet 26 is welded to the lower end of the inner annular protrusion 211 of the quartz sleeve 21 by using non-metallic solder, so as to form a vacuum insulation function of the electrode sheet 26 at both ends, so as to meet the requirement of isolating the anode and cathode reaction atmosphere in the high-temperature catalytic research system. During the experiment, different reaction gases are introduced into the two ends of the electrode sheet 26, and the current is controlled by using a power supply. At this time, the sampling cone 41 is located in the beam source chamber 15 at the upper end of the electrode sheet 26, and the gas phase product in the reaction is sampled and analyzed by the mass spectrometer 5.

[0062] Further, the sampling cone 41 is fixed on the ionization chamber 4, and the sampling cone 41 is located in the beam source chamber 15. The beam source chamber 15 is used for temporarily storing the gas phase product. A small amount of the gas phase product enters the sampling cone 41 and is further analyzed, and most of the gas phase product is pumped away through the vacuum port 111. The sampling cone 41 is coaxially arranged with the electrode sheet 26, and the nozzle tip of the sampling cone 41 is opposite to the center point of the electrode sheet 26, so as to facilitate the sampling and detection of the gas phase material. Preferably, the distance between the nozzle tip of the sampling cone 41 and the center point of the electrode sheet 26 is adjustable within 1-50 mm, and the distance can be adjusted by setting the position of the inner annular protrusion 211 of the quartz sleeve 21.

[0063] Further, the electrode sheet 26 is a circular sheet of solid material formed by sintering different material combinations, and the diameter of the electrode sheet 26 is between 6.5-7 mm. The anode of the electrode sheet 26 is directed to the nozzle tip of the sampling cone 41.

[0064] Further, the vacuum degree in the beam source chamber 15 is 1-10 Torr, and the vacuum in the ionization chamber 4 is 0.01-0.05 Pa. After the intermediate product is generated from the electrode sheet 26, it enters the ionization chamber 4 through the sampling cone 41 and is finally detected and analyzed by the mass spectrometer 5.

[0065] The working principle and working process of the present application are as follows:

[0066] 1、The present application is provided with two experimental inlet and outlet gas circulation paths. One experimental inlet and outlet gas circulation path is provided with a vacuum extraction port 111 and an inlet port 113 on the flange cavity 11, the inlet port 113 is connected to the gas path interface of the gas flow controller, the gas entering the inlet port 113 is 95% methane and 5% nitrogen. The gas flows through the upper surface of the electrode sheet 26, and then is extracted and evacuated through the vacuum extraction port 111. The vacuum gauge interface 112 is provided with a pressure detection device to detect the vacuum pressure state in real time. The inlet gas of the other experimental inlet and outlet gas circulation path enters from the end port of the center ceramic tube 23, blows the lower surface of the electrode sheet 26, and the gas after the experimental reaction is discharged through the third interface 253 of the inner sleeve tube 22. The gas entering the center ceramic tube 23 is pure carbon dioxide.

[0067] 2、The present application is provided with two water cooling systems, which are respectively the first circulating water channel 115 and the second circulating water channel 131. The water cooling system is constructed by circulating water, and the water flow carries away the excess heat conducted to the upper and lower parts of the reactor cavity 1, so as to protect the sealing effect of the O-ring on the upper silica gel gasket 27, the lower silica gel gasket 28 and the conversion joint 24.

[0068] 3、Experimental steps are as follows:

[0069] (1) First, install the electrode sheet 26 at the separate internal annular protrusion 211, and weld by using non-metal solder. Leave the first conductive gold wire 261 and the second conductive gold wire 262 at both ends of the electrode sheet 26. The anode (gold surface) of the electrode sheet 26 faces the sampling port of the sampling cone 41, and the gas entering the anode is 95% methane and 5% nitrogen.

[0070] (2) Independently from the first step, install one end of the flange cavity 11 on the ionization chamber 2, and seal by using the fluorine rubber sealing O-ring 14. Then, match and install the other end of the flange cavity 11 with the quartz sleeve tube 21, and seal by using the upper silica gel gasket 27, the lower silica gel gasket 28 and the flange port cover plate 17. At this time, the first conductive gold wire 261 at the upper end needs to be drawn out from the experimental gold wire inlet 114. The first water inlet pipe 116 and the first water outlet pipe 117 are connected to circulating water, the vacuum extraction port 111 is connected to a vacuum pump, the flow rate of the extracted gas can be controlled, and the vacuum gauge interface 112 is connected to a vacuum gauge to measure the vacuum degree.

[0071] (3) The fixed frame 12, the spring heating ring 161, the mullite heat insulation pad 162, the fluorine rubber sealing compression ring 134, the fluorine rubber radial sealing O-ring 135 and the like are coaxially sleeved on the quartz sleeve tube 21, and the fixed frame 12 is fixed on the flange cavity 11 by using bolts.

[0072] (4) Then, the end water cooling tank 13 is installed at the bottom of the fixed frame 12 by using bolts, wherein the second water inlet pipe 132 and the second water outlet pipe 133 are connected to circulating water. The reactor circulating water inlet pipe 511 and the reactor circulating water outlet pipe 512 are connected to circulating water.

[0073] (5) The quartz sleeve 21 is connected with the inner sleeve 22 through the conversion joint 24. The second conductive gold wire 262 at the lower end (negative side) of the electrode sheet 26 is led out from the inner sleeve 22. The center ceramic tube 23 is connected with the inner sleeve 22 through the tee joint 25. One end of the center ceramic tube 23 is about 1 mm away from the negative side of the electrode sheet 26. Pure carbon dioxide is introduced from the lower end of the center ceramic tube 23. The third interface 25312 of the tee joint 25 leads out the second conductive gold wire 262 and is connected with the vacuum pump. The flow rate of the vacuum pump can be controlled.

[0074] (6) After the installation of the experimental device, the experiment is carried out. First, 95% methane and 5% nitrogen are introduced from the gas inlet 113. Pure carbon dioxide is introduced from the lower end of the center ceramic tube 23. The vacuum degree of the beam source chamber 15 is controlled by controlling the flow rate of the vacuum pump and the third interface 253 of the gas outlet. The change of the vacuum degree can control the intensity of the chemical reaction. Low vacuum can keep the reaction intermediates for a long time, so as to be introduced into the ionization chamber 4 by the sampling cone 41 and be captured and analyzed by the mass spectrometer 5.

[0075] (7) After the gas and vacuum state are stable, the power supply is controlled by the external control current. The power supply above the electrode sheet 26 is controlled by the first conductive gold wire 261 and the second conductive gold wire 262. At this time, the anode will generate some products in the reaction system, such as methyl radicals, which can be captured and analyzed by the mass spectrometer 5.

[0076] (8) After the experiment is completed, the gas and vacuum are stopped. Then, the installation steps are reversed to disassemble and replace the electrode sheet 26. Another set of experiments can be carried out after reinstallation.

[0077] 4. Working principle:

[0078] In operation, 95% methane and 5% nitrogen are fed into the gas inlet 113, pure carbon dioxide is fed into the lower end of the central ceramic tube 23, and the flow of the sample gas is controlled by the flow meter. The vacuum pump is connected to the vacuum port 111 on the radial side of the beam source chamber 15, and the pressure in the reaction chamber is maintained at 1-10 Torr. The heating temperature of the threaded tube heating pipe 16 ranges from room temperature to 900 DEG C, and the heat is transmitted to the position of the electrode sheet 26 in the inner part through the quartz sleeve 21, so that the electrode sheet 26 is heated to a high temperature. The electrode sheet 26 is connected to the two poles of the power supply on the upper and lower surfaces, and in operation, the electrode sheet 26 serves as a material exchange channel and further generates a high-temperature electrocatalytic reaction. The reaction products on the upper anode surface of the electrode sheet 26 pass through the sampling cone 41 to form a molecular beam into the ionization chamber 4. The reaction products entering the ionization chamber 4 are ionized by the synchrotron radiation to form ions, and the product ions are transmitted to the mass spectrometer 5 through the ion transmission device of the ionization chamber 4, and the mass number of the product ions is analyzed by the mass spectrometer 5.

[0079] As shown in Figure 26 , Figure 27 , the solid oxide electrolysis cell research system is taken as an example, and the mass spectrum and signal intensity comparison chart of the key intermediate methyl radical in the oxygen evolution reaction of methane and carbon dioxide on the Au / YSZ electrode sheet interface under different currents (0uA, 30uA and 70uA) are shown, which proves that the device plays an important role in the detection of intermediate products in high-temperature electrocatalytic reactions.

[0080] The beneficial effects of the present application are:

[0081] (1) Due to the need to maintain vacuum, the sealing method of the reactor cavity mainly adopts O-ring sealing, which cannot withstand high temperature. The present application protects the sealing effect of the sealing surface by constructing a water cooling system at both ends of the reactor cavity and using water cooling, thereby improving the upper limit of the temperature zone of the reactor cavity, which can be increased from 600 DEG C to 900 DEG C, and the high temperature limit of the reactor cavity is improved.

[0082] (2) Since the electrode sheet is usually connected to the reactor by explosive gas, the electrode sheet cannot be mixed on both sides of the reactor. The present application fills non-metallic solder between the electrode sheet and the quartz reactor, and realizes the vacuum isolation of the electrode sheet on both sides by soldering, which provides technical support for the mass spectrometry detection device of high-temperature electrocatalysis.

[0083] (3) The inner ring sleeve structure and non-metallic soldering process are adopted to realize the vacuum isolation and positioning of the electrode sheet on both sides.

[0084] (4) The quartz sleeve, inner sleeve and central ceramic tube are sealed and connected into a whole by a conversion joint and a tee joint. On the premise of ensuring the sealing effect, the experimental requirements of directly blowing the surface of the electrode sheet by the inlet gas at the lower end and then removing it by the exhaust port are realized, and the route from the inner cavity to the external space is provided for the conductive gold wire. In addition, it is convenient to disassemble, and it can be reused by only replacing the electrode sheet.

[0085] (5) The position of the annular protrusion in the quartz sleeve can realize the distance control between the electrode sheet and the sampling cone, and the distance can be controlled in 1-50mm, so as to detect the product change at different distance positions of the electrode sheet.

[0086] (6) The electrode sheet is led from the vacuum to the atmospheric environment through the upper and lower two conductive gold wires, and the electrode sheet is connected with the external power supply. By controlling the current intensity of the external power supply, the reaction degree can be effectively in-situ current controlled, so as to observe the trend change of the product evolution caused by the current, and realize the in-situ detection of the vacuum electro-catalysis.

[0087] The above-described embodiments are only used to describe the preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. An in-situ detection device for gas-phase intermediate products of high-temperature electrocatalytic reactions, comprising a high-temperature electrocatalytic reactor (3), an ionization chamber (4), and a mass spectrometer (5) connected in sequence, characterized in that: The high-temperature electrocatalytic reactor (3) includes a reactor chamber (1) and a quartz tube reactor (2); The reactor cavity (1) includes a flange cavity (11), a fixing frame (12), and an end water-cooling tank (13) connected sequentially from top to bottom. One axial end of the flange cavity (11) is sealed to the ionization chamber (4) through a fluororubber O-ring (14), and the other axial end of the flange cavity (11) is sealed to the quartz sleeve (21) in the quartz tube reactor (2). The inner cavity of the flange cavity (11) is a beam source chamber (15), and the beam source chamber (15) is connected to the quartz tube reactor (2). The axially penetrating internal space constitutes the reaction chamber. The flange cavity (11) is provided with a vacuum port (111), a vacuum gauge interface (112), an air inlet (113), and an experimental gold wire inlet (114) that are connected to the beam source chamber (15). The flange cavity (11) is provided with a first circulating water channel (115) inside the cavity wall. The flange cavity (11) is also provided with a first water inlet pipe (116) and a first water outlet pipe (117) that are respectively connected to the two ends of the first circulating water channel (115). The reactor cavity (1) further includes a threaded heating tube (16) composed of a spring heating coil (161) and a mullite heat insulation pad (162). The threaded heating tube (16) is placed in a fixed frame (12) and coaxially sleeved on the quartz tube reactor (2). The fixed frame (12) is hollow and is fixed to the lower end of the flange cavity (11) by bolts. The mullite heat insulation pad (162) is located between the spring heating coil (161) and the end water cooling tank (13). The end water cooling tank (13) is cylindrical in shape. Its upper flange is bolted to the lower end of the fixed frame (12). The end water cooling tank (13) is coaxially mounted on the quartz tube reactor (2). The inner wall of the end water cooling tank (13) is provided with a second circulating water channel (131). The two ends of the second circulating water channel (131) are respectively connected to a second inlet pipe (132) and a second outlet pipe (133). The quartz tube reactor (2) includes a quartz sleeve (21), an inner sleeve (22) and a central ceramic tube (23) arranged coaxially and sequentially from the outside to the inside. The inner sleeve (22) includes an inner sleeve body (221) and a connecting pipe (222) arranged at the lower end of the inner sleeve body (221). One end of the connecting pipe (222) is sealed to the bottom end of the quartz sleeve (21) through a conversion joint (24). The other end of the connecting pipe (222) is sealed to the first interface (251) of the three-way connector (25) arranged on the central ceramic tube (23). The first interface (251) and the second interface (252) of the three-way connector (25) are arranged coaxially, and the central ceramic tube (23) passes through the first interface (251) and the second interface (252). The third interface (253) of the three-way connector (25) is a gas extraction port. The lower end of the central ceramic tube (23) is connected to the gas path interface of the gas flow controller. An electrode plate (26) is installed between the annular protrusion (211) inside the quartz sleeve (21) and the gap formed at the front end of the inner sleeve (22). The first conductive gold wire (261) led out from the upper surface of the electrode plate (26) is led out to the external power source through the experimental gold wire inlet (114). The second conductive gold wire (262) led out from the lower surface of the electrode plate (26) passes through the inner sleeve (22) and is finally led out to the external power source from the third interface (253).

2. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: The flange cavity (11) is provided with a flange opening (118) that mates with the quartz sleeve (21) at one end. The quartz sleeve (21) is provided with a disc-shaped body (212) that mates with the flange opening (118) at its upper position along the circumference. The upper and lower end faces of the disc-shaped body (212) are respectively provided with an upper silicone gasket (27) and a lower silicone gasket (28). The upper silicone gasket (27), the disc-shaped body (212) and the lower silicone gasket (28) are placed in the flange opening (118) and sealed and fixed with the flange cavity (11) through the flange opening cover plate (17).

3. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: A sampling cone (41) is fixed on the ionization chamber (4). The sampling cone (41) is located in the beam source chamber (15). The sampling cone (41) is coaxially arranged with the electrode plate (26), and the tip of the nozzle of the sampling cone (41) is directly facing the center point of the electrode plate (26). The distance between the tip of the nozzle of the sampling cone (41) and the center point of the electrode plate (26) is adjustable within 1 to 50 mm.

4. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: The electrode sheet (26) is a circular sheet solid material formed by sintering different materials. The diameter of the electrode sheet (26) is between 6.5 and 7 mm. The anode of the electrode sheet (26) faces the tip of the nozzle of the sampling cone (41).

5. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: The outer diameter of the electrode sheet (26) is smaller than the inner diameter of the quartz sleeve (21), and larger than the inner diameter of the annular protrusion (211) inside the quartz sleeve (21) and the outer diameter of the inner sleeve (22).

6. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: The terminal water-cooling tank (13) and the quartz sleeve (21) are provided with a fluororubber sealing pressure ring (134) and a fluororubber radial sealing O ring (135).

7. The in-situ detection device for gas-phase intermediate products in high-temperature electrocatalytic reactions according to claim 1, characterized in that: The vacuum level in the beam source chamber (15) is 1 to 10 Torr, and the vacuum level in the ionization chamber (4) is 0.01 to 0.05 Pa.

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