CN114405438B - Photoelectrocatalysis reaction system - Google Patents

Abstract

The invention relates to the technical field of photoelectric catalysis, in particular to a photoelectric catalytic reaction system, comprising a cathode reactor and an anode reactor, and an air inlet of the cathode reactor is sequentially connected with a first air pump and a first air pump for supplying reaction gas to the first air pump The first gas storage device, the outlet of the cathode reactor is connected with a first back pressure valve; the inlet of the anode reactor is sequentially connected with a second gas pump and a second gas storage device for providing inert gas to the second gas pump , the outlet of the anode reactor is connected with a second back pressure valve, the setting of the first back pressure valve and the second back pressure valve can make the pressure inside the cathode reactor and the anode reactor uniform, so that the reaction in the cathode reactor can be made uniform. The solubility of the gas remains in a stable state, thereby ensuring the stable and controlled photoelectric catalytic efficiency. In addition, the stable pressure also has a decisive impact on the stability and reproducibility of the gas chromatography test, which meets the requirements for accurate evaluation of the photoelectric catalytic reaction efficiency.

Description

A Photoelectric Catalytic Reaction System

technical field

The invention relates to the technical field of photoelectric catalysis, in particular to a photoelectric catalysis reaction system.

Background technique

Driven by clean solar energy, photoelectrocatalytic technology efficiently catalyzes reactions under mild conditions (near atmospheric pressure and ambient temperature), and has important applications in the production of high value-added chemicals and the decomposition of harmful pollutants. Compared with photocatalytic technology, the reduction and oxidation reactions in the photocatalytic process are spatially separated to avoid the recombination of photogenerated carriers in the semiconductor photocatalytic material on the surface of the photocatalyst; compared with electrocatalytic technology, photocatalytic directly converts light energy into Chemical energy, to avoid the energy loss caused by the multi-step conversion of solar energy-electric energy-chemical energy in the electrocatalytic process, so the theoretical solar energy utilization efficiency of photocatalytic technology is higher.

Ammonia is an important basic chemical, which has important applications in clean fuel, nitrogen fertilizer production, protein synthesis and other fields. At present, the main preparation method of ammonia is the Haber method, which requires high temperature and high pressure reaction conditions. The hydrogen required for the synthesis of ammonia by the Haber method is mainly prepared by water vapor shift reaction or natural gas reforming. It is a "ash" with high energy consumption and heavy carbon emissions. hydrogen". Therefore, the ammonia synthesis process by the Haber method no longer meets the needs of the current international community to achieve the goal of "carbon neutrality and carbon peak". Applying photoelectrocatalytic technology to ammonia synthesis reaction is a new technology with great potential for low energy consumption and zero carbon emission. The process of photocatalytic ammonia synthesis is carried out under mild conditions, using nitrogen and water as raw materials to synthesize ammonia, and the by-product is only oxygen, which fully meets the needs of today's "carbon neutrality and carbon peak" goals.

At present, nitrogen gas is injected into the cathode reactor through an air pump during photocatalytic synthesis of ammonia. The nitrogen gas is dissolved in the electrolyte in the cathode reactor, and then adsorbed on the working electrode immersed in the electrolyte. Turn on the light source to irradiate the working electrode, thereby generating dissolved ammonium ions in the electrolyte. However, there is a pulsation phenomenon in the nitrogen gas flowing out from the air pump, which will lead to pressure changes in the cathode reactor, which in turn will cause fluctuations in the solubility of nitrogen gas in the electrolyte, and solubility fluctuations will cause changes in the adsorption concentration of nitrogen gas on the surface of the photoelectrode. As a result, the photocatalytic reaction efficiency is not controlled, and it is impossible to accurately evaluate the photocatalytic reaction efficiency.

Contents of the invention

The object of the present invention is to provide a kind of photoelectric catalysis reaction system, the technical problem to be solved by the present invention is: existing photocatalytic reaction system, passes into the reaction gas in the cathode reactor through the air pump and there is pulsation phenomenon, causes in the cathode reactor The pressure changes so that the precise evaluation of the photocatalytic reaction efficiency cannot be performed.

In order to solve the above technical problems, the present invention provides a photoelectric catalytic reaction system, including a cathode reactor and an anode reactor, the air inlet of the cathode reactor is connected with a first air pump and a Provide the first gas storage device of reaction gas, the gas outlet of the cathode reactor is connected with the first back pressure valve; A second gas storage device for inert gas is provided, and a second back pressure valve is connected to the gas outlet of the anode reactor.

As a preferred solution, a first gas scrubbing and pressure stabilizing device is connected between the first gas pump and the cathode reactor, and a second gas scrubbing and pressure stabilizing device is connected between the second gas pump and the anode reactor.

As a preferred solution, a first flow controller is connected between the first gas scrubbing and pressure stabilizing device and the cathode reactor, and a second flow controller is connected between the second gas scrubbing and pressure stabilizing device and the cathode reactor. flow controller.

As a preferred solution, the photoelectric catalytic reaction system includes a first gas flow switching device, and the first gas flow switching device is provided with a first port, a second port, a third port and a fourth port that can switch communication states; One port communicates with the gas outlet of the first back pressure valve, the second port communicates with the intake port of the first air pump, the gas outlet of the first gas storage device and the second gas storage device The air outlets of the third port are connected with the third port, and the fourth port is connected with the first one-way valve for exhaust;

Switching the communication state of the first airflow switching device can make the first port communicate with the fourth port, and the second port communicate with the third port, or the first port communicate with the fourth port. The two ports are connected, and the third port is connected with the fourth port.

As a preferred solution, the photoelectric catalytic reaction system also includes a second gas flow switching device, the second gas flow switching device is provided with a fifth port, a sixth port, a seventh port and an eighth port that can switch the communication state, and the The gas outlet of the second gas storage device communicates with the fifth port;

The sixth port communicates with the intake end of the second air pump, the seventh port communicates with the outlet end of the second back pressure valve; the eighth port is connected with a second one-way valve for exhaust valve;

Switching the communication state of the second airflow switching device can make the fifth port communicate with the sixth port and the seventh port communicate with the eighth port, or the sixth port communicate with the first port The seven ports are in communication and the fifth port is in communication with the eighth port.

As a preferred solution, the photoelectric catalytic reaction system also includes a gas detection system and a third gas flow switching device for detecting the generated gas content, the gas detection system is provided with a first air inlet pipe and a first air outlet pipe, and the third The gas flow switching device is provided with a ninth port, a tenth port, an eleventh port and a twelfth port which can switch the communication state, the ninth port communicates with the gas outlet of the cathode reactor, and the tenth port communicates with the gas outlet of the cathode reactor. The first air intake pipe communicates, the eleventh port communicates with the first air outlet pipe, and the twelfth port communicates with the intake end of the first back pressure valve;

Switching the communication state of the third airflow switching device can make the ninth port communicate with the tenth port and the eleventh port communicate with the twelfth port, or the ninth port communicate with the The twelfth port is in communication with the tenth port and the eleventh port is in communication.

As a preferred solution, the gas detection system includes a gas chromatograph, a sampling device and a third gas storage device for feeding an inert gas into the sampling device;

The sampling device is provided with a first interface, a second interface, a third interface, a fourth interface, a fifth interface and a sixth interface that can switch the connection state, and the outlet of the first interface and the third gas storage device The air port is connected, the second interface is connected with the first quantitative loop, the other end of the first quantitative loop is connected with the fifth interface, the third interface is connected with the first intake pipe, and the first quantitative loop is connected with the fifth interface. The four ports are in communication with the first gas outlet pipe, and the sixth port is in communication with the air inlet of the gas chromatograph;

Switching the connection state of the sampling device can make the third interface, the second interface, the first quantitative loop, the fifth interface and the fourth interface communicate in sequence, or the first The interface, the second interface, the first quantitative loop, the fifth interface and the sixth interface are connected in sequence.

As a preferred solution, the photoelectric catalytic reaction system includes a fourth gas flow switching device, and the fourth gas flow switching device is provided with the thirteenth port, the fourteenth port, the fifteenth port and the sixteenth port that can switch the communication state , the thirteenth port communicates with the inlet end of the second back pressure valve, and the fourteenth port communicates with the gas outlet of the anode reactor;

The sampling device is also provided with the seventh interface, the eighth interface, the ninth interface and the tenth interface which can switch the connection state, the seventh interface is connected with the second quantitative loop, and the other end of the second quantitative loop is connected The tenth interface, the eighth interface communicates with the sixteenth port, and the ninth interface communicates with the fifteenth port;

Switching the connection state of the sampling device can make the ninth interface, the tenth interface, the second quantitative loop, the seventh interface and the eighth interface communicate in sequence; or the first interface , the tenth interface, the second quantitative loop, the seventh interface and the sixth interface are sequentially connected;

Switching the communication state of the fourth airflow switching device can make the thirteenth port communicate with the sixteenth port and the fifteenth port communicate with the fourteenth port, or the thirteenth port port communicates with the fourteenth port and the fifteenth port communicates with the sixteenth port.

As a preferred solution, a particle exchange membrane for preventing gas generated in the cathode reactor from entering the anode reactor is interposed between the cathode reactor and the anode reactor.

Compared with the prior art, the beneficial effect of the present invention is that: the photoelectric catalytic reaction system of the present invention is connected with a first back pressure valve at the gas outlet of the cathode reactor, and is provided with a second back pressure valve at the gas outlet of the anode reactor , the setting of the first back pressure valve and the second back pressure valve can make the pressure inside the cathode reactor and the anode reactor uniform, so that the solubility of the reaction gas in the cathode reactor remains stable, thereby ensuring the photocatalytic efficiency. Stable and controlled, it meets the requirements for precise evaluation of photocatalytic reaction efficiency.

Description of drawings

Fig. 1 is the structural representation of photoelectrocatalytic reaction system of the present invention;

Fig. 2 is a partially enlarged schematic diagram of the first airflow switching device;

3 is a partial enlarged schematic diagram of a second airflow switching device;

4 is a partially enlarged schematic diagram of a third airflow switching device;

5 is a partially enlarged schematic diagram of a fourth airflow switching device;

Fig. 6 is a schematic diagram when the sampling device is in a first state;

Fig. 7 is a partially enlarged schematic diagram when the sampling device is in a second state;

In the figure, 1. Cathode reactor; 2. Anode reactor; 3. The first gas pump; 4. The first gas storage device; 5. The first back pressure valve; 6. The second gas pump; 7. The second gas storage device ; 8, the second back pressure valve; 9, the first gas washing and stabilizing device; 10, the second scrubbing and stabilizing device; 11, the first flow controller; 12, the second flow controller; 13, the first air flow Switching device; 131, first port; 132, second port; 133, third port; 134, fourth port; 14, second airflow switching device; 141, fifth port; 142, sixth port; 143, the first Seven ports; 144, the eighth port; 15, the first one-way valve; 16, the second one-way valve; 17, the third airflow switching device; 171, the ninth port; 172, the tenth port; 173, the eleventh Port; 174, the twelfth port; 18, the first air inlet pipe; 19, the first air outlet pipe; 20, the gas chromatograph; 21, the sampling device; 21-1, the first interface; 21-2, the second interface; 21-3, the third interface; 21-4, the fourth interface; 21-5, the fifth interface; 21-6, the sixth interface; 21-7, the seventh interface; 21-8, the eighth interface; 21- 9. The ninth interface; 21-10, the tenth interface; 21-11, the first quantitative loop; 21-12, the second quantitative loop; 22, the third gas storage device; 23, the fourth airflow switching device; 231 , the thirteenth port; 232, the fourteenth port; 233, the fifteenth port; 234, the sixteenth port; 24, the second air intake pipe; 25, the second air outlet pipe; 26, the fifth air flow switching device; 27 , the first pressure reducing valve; 28, the first flow meter; 29, the second pressure reducing valve; 30, the second flow meter; 31, the gas washing bottle; 32, the first condensation pipe; 33, the second condensation pipe; 34 , the third decompression valve; 35, the electrochemical workstation.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom" etc. Orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish information of the same type from each other. For example, "first" information may also be referred to as "second" information without departing from the scope of the present invention, and similarly, "second" information may also be referred to as "first" information.

As shown in Fig. 1 to Fig. 7, the preferred embodiment of the photoelectric catalytic reaction system of the present invention, comprises cathode reactor 1 and anode reactor 2, and the air inlet of described cathode reactor 1 is connected with first air pump 3 and The first gas storage device 4 for supplying reaction gas to the first gas pump 3, the gas outlet of the cathode reactor 1 is connected with the first back pressure valve 5; the gas inlet of the anode reactor 2 is connected with the first A second gas pump 6 and a second gas storage device 7 for supplying inert gas to the second gas pump 6 , the gas outlet of the anode reactor 2 is connected with a second back pressure valve 8 . The setting of the first back pressure valve 5 and the second back pressure valve 8 can make the pressure inside the cathode reactor 1 and the anode reactor 2 uniform, thereby making the solubility of the reactant gas in the cathode reactor 1 maintain a stable state, thereby ensuring The stability of photocatalytic efficiency is controlled; on the other hand, when a gas chromatograph is installed in the photocatalytic reaction system, the stable pressure in the reactor can ensure that the volume and pressure of the gas to be measured entering the quantitative loop remain stable, thereby ensuring that the gas entering the gas chromatograph The amount of the sample substance is stable, and the above two aspects together help the system to meet the requirements for accurate evaluation of the photoelectrocatalytic reaction efficiency.

Wherein, a first gas washing and stabilizing device 9 is connected between the first gas pump 3 and the cathode reactor 1, and a second gas scrubbing and stabilizing device is connected between the second gas pump 6 and the anode reactor 2. Pressure device 10, specifically, in the present embodiment, the first gas washing and stabilizing device and the second scrubbing and stabilizing device are pressure stabilizing bottles, and the air inlet of the stabilizing bottle is arranged at the bottom of the inner chamber of the bottle, and the pressure stabilizing bottle The gas outlet is set on the top of the inner cavity of the bottle, so as to realize the buffering of the gas flow entering the pressure regulator bottle, reduce the pulsation of the gas flowing out from the first gas pump 3 or the second gas pump 6, and ensure the passage into the cathode reactor 1 and the anode reaction The pressure of the gas in the device 2 is stable. Preferably, acidic liquid is contained in the regulator bottle in the present embodiment, and the bottle opening of the regulator bottle is sealed and inserted with an air inlet pipe and an air outlet pipe, and the air inlet pipe is positioned at an end outside the regulator bottle and the gas outlet of the first air pump 3 The end of the air inlet pipe located in the pressure regulator bottle is inserted in the acidic liquid; the end of the gas outlet pipe located in the pressure regulator bottle is set above the liquid level of the acidic liquid, and the end of the gas outlet pipe located outside the pressure regulator bottle is connected to the cathode reactor. The air inlet is connected; the setting of the acidic liquid can not only make the voltage stabilizing function of the regulator bottle better, but also absorb the soluble gas contained in the gas passing into the cathode reactor, so as to avoid the soluble gas from contaminating the electrolysis in the cathode reactor. liquid; in other embodiments of the present invention, if the reaction atmosphere does not contain soluble gas pollutants, the first scrubbing and pressure stabilizing device 9 and the second gas scrubbing and stabilizing device 10 can be surge tanks or balloons.

In this embodiment, a first flow controller 11 is connected between the first gas scrubbing and pressure stabilizing device 9 and the cathode reactor 1, and the second gas scrubbing and pressure stabilizing device 10 is connected to the anode reactor 2. A second flow controller 12 is connected between them. The setting of the first flow controller 11 and the second flow controller 12 can respectively control the flow of air flowing into the cathode reactor 1 and the anode reactor 2, and improve the requirements for regulation and control of the photoelectrocatalytic reaction parameters of the photoelectrocatalytic reaction system.

It should be noted that the reaction rate of the photoelectric catalytic reaction is relatively slow. After the reaction gas is introduced into the cathode reactor, most of the reaction gas cannot be dissolved in the electrolyte of the cathode reactor, and the reaction gas that is not dissolved in the electrolyte, It will be discharged from the gas outlet of the cathode reactor.

In order to improve the utilization efficiency of the reaction gas, in this embodiment, the photoelectric catalytic reaction system includes a first gas flow switching device 13, and the first gas flow switching device 13 is provided with a first port 131 and a second port that can switch the communication state. 132 and the third port 133 and the fourth port 134; the first port 131 communicates with the outlet end of the first back pressure valve 5, and the second port 132 communicates with the intake end of the first air pump 3 , the gas outlet of the first gas storage device 4 and the gas outlet of the second gas storage device 7 are in communication with the third port 133, and the fourth port is connected with a first one-way valve for exhaust (15); the first gas pump 3, the first gas washing and stabilizing device 9, the first flow controller 11, the cathode reactor 1, the first back pressure valve 5 and the first air flow switching device are connected in sequence through pipelines to form the cathode Gas circulation pipeline, open the second gas storage device before the reaction starts, switch the communication state of the first gas flow switching device 13 so that the first port 131 communicates with the fourth port 134, and the second port 132 In communication with the third port 133, the inert gas in the second gas storage device passes into the cathode circulation pipeline and is discharged from the fourth port 134, so that the air in the cathode circulation pipeline is discharged from the first one-way valve 15, The first one-way valve 15 can prevent outside air from entering the cathode circulation pipeline; realize the gas washing of the cathode circulation pipeline; after the gas washing is completed, close the second gas storage device, open the first gas storage device 4, and react gas from the first gas storage device 4 A gas storage device 4 flows into the cathode gas circulation pipeline, so that the reaction gas concentration in the cathode gas circulation pipeline increases, ensuring the demand for the reaction gas of the cathode reactor 1 during the photocatalytic reaction; after that, switch the first gas flow The communication state of the switching device 13 makes the first port 131 communicate with the second port 132, and makes the third port 133 communicate with the fourth port 144. At this time, the cathode gas pipeline forms a closed pipeline, and the first port 131 communicates with the second port 132. Driven by the gas pump 3, the gas in the cathode gas circulation pipeline is repeatedly passed into the cathode reactor 1, and then flows out from the cathode reactor 1. As the photoelectric catalytic reaction proceeds, the content of the reaction gas in the cathode gas circulation pipeline will increase. At this time, switch the connection state of the first gas flow switching device 13 again, and feed the reaction gas into the cathode gas circulation pipeline, thereby ensuring the effective utilization rate of the reaction gas.

In this embodiment, the photoelectric catalytic reaction system further includes a second gas flow switching device 14, and the second gas flow switching device 14 is provided with a fifth port 141, a sixth port 142 and a seventh port 143 and The eighth port 144, the gas outlet of the second gas storage device 7 communicates with the fifth port 141; the sixth port 142 communicates with the intake end of the second air pump 6, and the seventh port 143 It communicates with the gas outlet end of the second back pressure valve 8; specifically, the second gas pump 6, the second scrubbing and stabilizing device 10, the second flow controller 12, the anode reactor 2, the second back pressure valve 8 and The second gas flow switching devices 14 are sequentially connected through pipelines to form an anode gas circulation pipeline. Before the photocatalytic reaction starts, switch the communication state of the second gas flow switching device 14 so that the fifth port 141 is connected to the first gas flow switching device 14. The six ports 142 are in communication and the seventh port 143 is in communication with the eighth port 144, and the inert gas in the second gas storage device 7 is passed into the anode gas circulation pipeline, thereby exhausting the air in the anode gas circulation pipeline. At the same time, the eighth port 144 is connected with a second one-way valve 16 for exhaust, and the second one-way valve 16 can prevent air from entering the anode gas circulation pipeline; after that, switch the connection of the second gas flow switching device 14 again. state, so that the sixth port 142 communicates with the seventh port 143 and the fifth port 141 communicates with the eighth port 144 so that the anode gas circulation line is in a closed cycle state, preventing the inert gas from flowing into the air and causing waste of inert gas.

Further, as shown in FIG. 1, the photoelectric catalytic reaction system also includes a fifth gas flow switching device 26, and the fifth gas flow switching device 26 is provided with the seventeenth port, the eighteenth port and the nineteenth port that can switch the communication state. port, the first gas storage device 4 and the second gas storage device 7 are connected to the seventeenth port, the eighteenth port is connected to the third port 133, and the nineteenth port is connected to the fifth port 141; The communication state of device 26 can make the seventeenth port communicate with the eighteenth port, or make the seventeenth port communicate with the eighteenth port and the nineteenth port; It is connected with the eighteenth port and the nineteenth port, and the inert gas is simultaneously introduced into the cathode gas circulation pipeline and the anode gas circulation pipeline through the second gas storage device 7, and the cathode gas circulation pipeline and the anode gas circulation pipeline are connected. After the exhaust is completed, switch the connection state of the fifth gas flow switching device 26, so that the seventeenth port and the eighteenth port are connected to the cathode gas selection pipeline to feed the reaction gas; the fifth gas flow switching The arrangement of the device 26 makes the overall structure of the photocatalytic reaction system more compact.

In this embodiment, in order to facilitate the detection of the reaction gas content in the cathode gas circulation pipeline, the photoelectric catalytic reaction system also includes a gas detection system and a third gas flow switching device 17 for detecting the generated gas content, the gas detection system A first air inlet pipe 18 and a first air outlet pipe 19 are provided, and the third air flow switching device 17 is provided with a ninth port 171, a tenth port 172, an eleventh port 173 and a twelfth port 174 which can switch the communication state , the ninth port 171 communicates with the gas outlet of the cathode reactor 1, the tenth port 172 communicates with the first gas inlet pipe 18, and the eleventh port 173 communicates with the first gas outlet pipe 19 connected, the twelfth port 174 communicates with the intake end of the first back pressure valve 5; when detecting the reaction gas content of the cathode gas circulation pipeline, switch the communication state of the third gas flow switching device 17, so that The ninth port 171 communicates with the tenth port 172 and the eleventh port 173 communicates with the twelfth port 174, so that the gas in the cathode gas circulation line flows into the gas detection through the first gas inlet pipe 18 System, then flows out from the gas detection system through the first gas outlet pipe 19, so as to realize the detection of the reaction gas content in the cathode gas circulation pipeline, and then switch the connection state of the third gas flow switching device 17 again, so that the ninth port 171 communicates with the twelfth port 174 and the tenth port 172 communicates with the eleventh port 173 , thereby ensuring that the cathode gas circulation pipeline is in a closed cycle state. It should be noted that the setting of the third gas flow switching device 17 makes the cathode gas circulation line always follow the first gas pump 3, the first scrubbing and pressure stabilizing device 9, the first flow controller 11, the cathode reaction 1, the third gas flow switching device 17, the first back pressure valve 5 and the path flow of the first gas flow switching device, which eliminates the influence of the gas detection system due to the change of the gas pressure in the cathode reactor during the sampling process; the present application In other embodiments, the third airflow switching device 17 is arranged between the outlet end of the first back pressure valve 5 and the inlet end of the first air pump 3, thereby further avoiding the negative reaction of the third airflow switching device 17 during the switching process. The fluctuation of the air pressure in the device 1.

Specifically, as shown in Fig. 1, Fig. 6 and Fig. 7, the gas detection system includes a gas chromatograph 20, a sampling device 21 and a third gas storage device 22 for feeding an inert gas into the sampling device 21; The sampling device 21 is provided with a first interface 21-1, a second interface 21-2, a third interface 21-3, a fourth interface 21-4, a fifth interface 21-5 and a sixth interface 21 that can switch the connection state. -6, the first interface 21-1 communicates with the gas outlet of the third gas storage device 22, the second interface 21-2 is connected with a first quantitative loop 21-11, and the first quantitative The other end of the ring 21-11 is connected to the fifth interface 21-5, the third interface 21-3 communicates with the first air intake pipe 18, and the fourth interface 21-4 communicates with the first air outlet pipe 19, the sixth interface 21-6 communicates with the air inlet of the gas chromatograph 20;

When sampling, first switch the connection state of the third gas flow switching device 17, so that the gas in the cathode gas circulation line flows into the first intake pipe 18, and then switch the connection state of the sampling device 21, so that the sampling device 21 is in the state shown in Figure 6. In the first state shown, at this time, the third interface 21-3, the second interface 21-2, the first quantitative loop 21-11, the fifth interface 21-5 and the first The four ports 21-4 are connected sequentially, and the reaction gas flowing into the intake pipe 18 flows into the first quantitative loop 21-11 through the third port 21-3 and the second port 21-2, and passes through the first quantitative loop 21-11. The five ports 21-5 and the fourth port 21-4 flow to the first gas outlet pipe 19; after the sampling is completed, switch the communication state of the third gas flow switching device 17, and stop feeding the cathode reaction gas into the first gas inlet pipe 18 , and switch the connection state of the sampling device 21, so that the sampling device 21 is in the second state shown in Figure 7, at this time the first interface 21-1, the second interface 21-2, the first A certain measuring loop 21-11, the fifth port 21-5 and the sixth port 21-6 are connected in sequence, so that the inert gas in the third gas storage device 22 passes into the first quantitative loop 21-11 , so that the cathode reaction gas remaining in the first quantitative loop 21 - 11 is discharged to the gas chromatograph 20 .

Further, in order to detect the reaction gas in the anode gas circulation pipeline, in this embodiment, the photoelectric catalytic reaction system includes a fourth gas flow switching device 23, and the fourth gas flow switching device 23 is provided with a switchable communication state The thirteenth port 231, the fourteenth port 232, the fifteenth port 233 and the sixteenth port 234, the thirteenth port 231 communicates with the intake port of the second back pressure valve 8, the first Fourteen ports 232 communicate with the gas outlet of the anode reactor 2; the sampling device 21 is also provided with a seventh interface 21-7, an eighth interface 21-8, a ninth interface 21-9 and a switchable communication state. The tenth interface 21-10, the seventh interface 21-7 is connected to the second quantitative loop 21-12, the other end of the second quantitative loop 21-12 is connected to the tenth interface 21-10, the first The eighth interface 21-8 communicates with the sixteenth port 234, and the ninth interface 21-9 communicates with the fifteenth port 233; specifically, as shown in Figures 1 and 5, the gas detection system is provided with The second air inlet pipe 24 and the second air outlet pipe 25, one end of the second air inlet pipe 24 is connected to the ninth interface 21-9, the other end of the second air inlet pipe 24 is connected to the fifteenth port 233, and one end of the second air outlet pipe 25 is connected to The eighth interface 21-8, the other end of the second gas outlet pipe 25 is connected to the sixteenth port 234; when it is necessary to detect the reaction gas content in the anode gas circulation pipeline, first switch the connection of the fourth gas flow switching device 23 state, so that the thirteenth port 231 communicates with the sixteenth port 234 and the fifteenth port 233 communicates with the fourteenth port 232, so that the gas in the anode gas circulation pipeline flows into the second Intake pipe 24, then switch the connection state of the sampling device 21, so that the sampling device 21 is in the second state as shown in Figure 7, at this time the ninth interface 21-9, the tenth interface 21 -10. The second quantitative loop 21-12, the seventh port 21-7 and the eighth port 21-8 are sequentially connected to pass the anode reaction gas in the second gas inlet pipe 24 into the second quantitative loop 21-12; then switch the connection state of the sampling device 21 again, so that the sampling device 21 is in the first state as shown in Figure 6, at this time the first interface 21-1, the tenth interface 21-10, the second quantitative loop 21-12, the seventh port 21-7 and the sixth port 21-6 are connected in sequence, so that the inert gas in the third gas storage device 22 is passed into the second quantitative In the loop 21-12, the anode reaction gas remaining in the second quantitative loop 21-12 is discharged to the gas chromatograph 20. The setting of the sampling device 21 enables only one gas chromatograph to meet the detection of the cathode gas product and the anode gas product, which greatly reduces the equipment cost of the photocatalytic reaction system, and makes the overall layout of the photocatalytic reaction system more compact . It should be noted that the pressure fluctuation in the cathode reactor will cause the pressure change in the first quantitative loop, the pressure fluctuation in the anode reactor will cause the pressure change in the second quantitative loop, the first quantitative loop and the second quantitative loop The pressure change in the quantitative loop will cause the amount of sample entering the gas chromatograph to fluctuate each time, which will lead to poor reproducibility of the evaluation of the photoelectric catalytic reaction efficiency. In this application, the setting of the first back pressure valve and the second back pressure valve can make The pressure inside the cathode reactor and the anode reactor is uniform, so that the requirement for accurate evaluation of the photoelectric catalytic reaction efficiency is realized.

In this embodiment, as shown in FIG. 1 , the gas outlet of the first gas storage device 4 is sequentially connected with a first pressure reducing valve 27 and a first flow meter 28 , so as to control the pressure and pressure of the gas flowing out of the first gas storage device 4 . The flow is monitored and adjusted to improve the evaluation accuracy of the photoelectrocatalytic system of the present embodiment to the efficiency of the photocatalytic reaction; the fifth gas flow switching device 26 and the first gas flow switching device 13 are provided with a gas washing bottle 31, and in the gas washing bottle 31 A solution for absorbing the same gas as the cathode product or other soluble gas impurities is provided, thereby removing the gas mixed in the cathode gas circulation pipeline from the first gas storage device 4 or the second gas storage device 7. The similar products generated in the non-cathode reactor brought by the outside world further improve the evaluation accuracy of the photocatalytic reaction efficiency of the photocatalytic system of this embodiment; specifically, in this embodiment, the gas stored in the first gas storage device 4 It is nitrogen, and the gas generated after the nitrogen is passed into the cathode reactor 1 is ammonia, and the solution in the first gas washing bottle is an acidic solution, thereby removing the ammonia mixed in the gas passing into the cathode gas circulation pipeline . The gas outlet of the second gas storage device 7 is connected with the second decompression valve 29 and the second flow meter 30 in turn, the gas outlet of the third gas storage device 22 is connected with the third decompression valve 34, and the gas outlet of the cathode reactor 1 Connect to the third gas flow switching device through the first air pipe, the first condensation pipe 32 is wrapped on the outside of the first air pipe, the gas outlet of the anode reactor 2 is connected to the fourth air flow switching device through the second air pipe, and the outside of the second air pipe is wrapped with The second condensation pipe 33 .

In this embodiment, a particle exchange membrane is inserted between the cathode reactor 1 and the anode reactor 2 to prevent the generated gas in the cathode reactor 1 from entering the anode reactor 2 . Specifically, an H-shaped structure is formed between the cathode reactor 1 and the anode reactor 2, and the particle exchange membrane is arranged in the middle of the H-type structure. Oxygen is mixed in the same liquid and gas phases at the same time, resulting in the re-oxidation of the cathode-reduced products at the anode, which is crucial to ensure the accuracy of the evaluation of the photoelectrocatalytic reaction efficiency.

In this embodiment, in order to further improve the evaluation accuracy of the photoelectric catalytic reaction efficiency, the gas in the first gas storage device 4 is a nitrogen 15 isotope gas, so as to avoid the photoelectric interference of the nitrogen 14 existing in the air on the photoelectric catalytic reaction system. Influence of Accuracy on Estimation of Catalytic Reaction Efficiency.

The working process of the photocatalytic reaction system of the present invention is described below by taking photoelectric catalytic reaction ammonia as an example:

The first step is gas washing; specifically, unscrew the second gas storage device 7, adjust the pressure of the argon gas flowing out of the second gas storage device 7 to 0.3MPa through the second decompression valve 29, and the argon gas passes through the fifth The gas flow switching device 26 is divided into two paths, the first path flows into the gas washing bottle 31, and then flows to the first gas flow switching device 13, and flows into the cathode gas circulation pipeline through the first gas flow switching device 13, and the cathode gas circulation pipeline The air in the cathode gas circulation pipeline is exhausted to avoid the influence of the air in the cathode gas circulation pipeline on the photocatalytic reaction efficiency; the second path flows to the second airflow switching device 14, and flows into the anode gas circulation pipeline through the second airflow switching device to convert the anode gas into the anode gas circulation pipeline. The air in the circulation pipeline is exhausted to avoid the influence of the air in the anode gas circulation pipeline on the efficiency of the photocatalytic reaction.

The second step is to feed nitrogen into the cathode gas circulation pipeline; specifically, close the second gas storage device 7, open the first gas storage device 4, and the nitrogen in the first gas storage device 4 passes through the first pressure reducing valve 27 in sequence , the first flowmeter 28, the fifth gas flow switching device 26, the gas washing bottle 31, and the first gas flow switching device 13 flow into the cathode gas circulation pipeline, and the nitrogen exhausts the argon in the cathode gas circulation pipeline, and removes the cathode gas During the process of argon in the circulation pipeline, the nitrogen content in the cathode gas circulation pipeline is detected by switching the connection state of the third gas flow switching device 17 and the connection state of the sampling device 21, when the cathode gas circulation pipeline If the nitrogen content in the cathode is higher than 90%, it can be regarded as full, and then switch the connection state of the first gas flow switching device 13, so that the cathode gas circulation pipeline is in a closed cycle state.

The third step is the photoelectrocatalytic reaction; specifically, light is applied to the cathode reactor 1, and the electrochemical workstation 35 is turned on to start photoelectrocatalytic ammonia production. During the photocatalytic reaction, the first flow controller 11 and the second flow The combination of the controller 12 can realize the stable control of the reaction gas flow rate; the combination of the first back pressure valve 5 and the second back pressure valve 8 can realize the stable control of the pressure of the cathode reactor and the anode reactor, and the cathode gas circulation tube The gas products in the pipeline and the gas products in the anode gas circulation pipeline can be sampled online through the sampling device 21 and detected in real time by the gas chromatograph 20 . Wherein the gas chromatograph can only detect the gas composition of one gas path at the same time. If it is necessary to detect the gas content in the cathode gas pipeline, the second gas inlet pipe 24 needs to be in a non-gas intake state.

The fourth step is to supplement nitrogen; specifically, when the nitrogen content in the cathode gas circulation pipeline drops to 50%, it is necessary to supplement nitrogen to the cathode gas circulation pipeline. Now, open the first decompression valve 27, make nitrogen flow to the first air flow switching device through the first flow meter 28, the fifth air flow switching device, and the gas washing bottle 31, and switch the communication state of the first air flow switching device, so that the first flow switching device The first port 131, the second port 132 and the third port 133 are all connected, nitrogen flows into the cathode gas circulation pipeline, so that the reaction gas concentration in the cathode gas circulation pipeline rises, ensuring that the cathode gas in the photocatalytic reaction is carried out. Reactor 1 demand for reaction gas.

To sum up, the present invention provides a kind of photoelectric catalytic reaction system, the setting of its first back pressure valve 5 and the second back pressure valve 8 can make the pressure inside the cathode reactor 1 and the anode reactor 2 uniform, so that the cathode The solubility of the reaction gas in the reactor 1 is kept in a stable state, thereby ensuring the stability and control of the photoelectric catalytic efficiency; The amount of sample substance entering the gas chromatograph is stable, and the above two aspects together help the system to realize the precise evaluation requirements of the photoelectric catalytic reaction efficiency; through the first gas scrubbing and pressure stabilizing device and the second gas scrubbing and voltage stabilizing device, it is ensured that the gas flowing into the cathode The pressure of the gas in the reactor 1 and the anode reactor 2 is stable; the setting of the first flow controller 11 and the second flow controller 12 can control the flow of gas flowing into the cathode reactor 1 and the anode reactor 2 respectively, The monitoring precision requirements for the photoelectric catalytic efficiency of the photoelectric catalytic reaction system are improved; through the setting of the first gas flow switching device 13, the cathode gas circulation pipeline can maintain a closed cycle, and the reaction can be introduced into the cathode gas circulation system in time Gas; through the setting of the second gas flow switching device 14, the anode gas circulation pipeline can be kept in a closed cycle, avoiding the influence of the outside air on the evaluation accuracy of the photoelectric catalytic efficiency; through the sampling device 21, the third gas flow switching device 17 and the first With the cooperation of the four gas flow switching devices, the gas products in the cathode gas circulation pipeline and the gas products in the anode gas circulation pipeline can be sampled online through the sampling device 21, and real-time detection is carried out by the gas chromatograph 20; The setting of the membrane avoids the situation that the ammonia gas generated in the anode reactor and the oxygen generated in the cathode reactor are mixed in the same liquid phase and gas phase at the same time, and the resulting cathode reduction product is re-oxidized at the anode; by Nitrogen is set as an isotopic gas, which avoids the influence of external gases on the evaluation of photocatalytic reaction efficiency; the photocatalytic system formed by the cooperation of the above-mentioned characteristics not only improves the effective utilization rate of nitrogen, but also ensures the efficiency of photocatalytic reaction. Accurate assessment requirements.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, some improvements and replacements can also be made, these improvements and replacements It should also be regarded as the protection scope of the present invention.

Claims (8)

1. The photoelectrocatalysis reaction system is characterized by comprising a cathode reactor (1) and an anode reactor (2), wherein an air inlet of the cathode reactor (1) is sequentially connected with a first air pump (3) and a first air storage device (4) used for providing reaction gas for the first air pump (3), and an air outlet of the cathode reactor (1) is connected with a first back pressure valve (5); the air inlet of the anode reactor (2) is sequentially connected with a second air pump (6) and a second air storage device (7) for providing inert gas for the second air pump (6), and the air outlet of the anode reactor (2) is connected with a second back pressure valve (8); the photoelectrocatalysis reaction system comprises a first gas flow switching device (13), wherein the first gas flow switching device (13) is provided with a first port (131), a second port (132), a third port (133) and a fourth port (134) which can be switched into a communication state; the first port (131) is communicated with the air outlet end of the first backpressure valve (5), the second port (132) is communicated with the air inlet end of the first air pump (3), the air outlet of the first air storage device (4) and the air outlet of the second air storage device (7) are communicated with the third port (133), and the fourth port (134) is connected with a first one-way valve (15) for exhausting air;

switching the communication state of the first airflow switching device (13) may cause the first port (131) to communicate with the fourth port (134) and the second port (132) to communicate with the third port (133), or the first port (131) to communicate with the second port (132) and the third port (133) to communicate with the fourth port (134).

2. The photoelectrocatalysis reaction system according to claim 1, wherein a first washing and pressure stabilizing device (9) is connected between the first air pump (3) and the cathode reactor (1), and a second washing and pressure stabilizing device (10) is connected between the second air pump (6) and the anode reactor (2).

3. The photoelectrocatalysis reaction system according to claim 2, wherein a first flow controller (11) is connected between the first washing and pressure stabilizing device (9) and the cathode reactor (1), and a second flow controller (12) is connected between the second washing and pressure stabilizing device (10) and the anode reactor (2).

4. The photoelectrocatalysis reaction system according to claim 1, further comprising a second gas flow switching device (14), wherein the second gas flow switching device (14) is provided with a fifth port (141), a sixth port (142), a seventh port (143) and an eighth port (144) which can switch the communication state, and the gas outlet of the second gas storage device (7) is communicated with the fifth port (141);

the sixth port (142) is communicated with the air inlet end of the second air pump (6), and the seventh port (143) is communicated with the air outlet end of the second backpressure valve (8); a second one-way valve (16) for exhausting is connected to the eighth port (144);

switching the communication state of the second gas flow switching device (14) may cause the fifth port (141) to communicate with the sixth port (142) and the seventh port (143) to communicate with the eighth port (144), or the sixth port (142) to communicate with the seventh port (143) and the fifth port (141) to communicate with the eighth port (144).

5. The photoelectrocatalysis reaction system according to claim 1, further comprising a gas detection system for detecting the content of generated gas and a third gas flow switching device (17), wherein the gas detection system is provided with a first gas inlet pipe (18) and a first gas outlet pipe (19), the third gas flow switching device (17) is provided with a ninth port (171), a tenth port (172), an eleventh port (173) and a twelfth port (174) which can be switched to the communication state, the ninth port (171) is communicated with the gas outlet of the cathode reactor (1), the tenth port (172) is communicated with the first gas inlet pipe (18), the eleventh port (173) is communicated with the first gas outlet pipe (19), and the twelfth port (174) is communicated with the gas inlet end of the first backpressure valve (5);

switching the communication state of the third air flow switching device (17) may cause the ninth port (171) to communicate with the tenth port (172) and the eleventh port (173) to communicate with the twelfth port (174), or the ninth port (171) to communicate with the twelfth port (174) and the tenth port (172) to communicate with the eleventh port (173).

6. The photoelectrocatalytic reaction system according to claim 5, wherein the gas detection system comprises a gas chromatograph (20), a sampling device (21), and a third gas storage device (22) for introducing an inert gas into the sampling device (21);

the sampling device (21) is provided with a first interface (21-1), a second interface (21-2), a third interface (21-3), a fourth interface (21-4), a fifth interface (21-5) and a sixth interface (21-6) which can be switched to be in a communication state, the first interface (21-1) is communicated with an air outlet of the third air storage device (22), the second interface (21-2) is connected with a first quantitative ring (21-11), the other end of the first quantitative ring (21-11) is connected with the fifth interface (21-5), the third interface (21-3) is communicated with the first air inlet pipe (18), the fourth interface (21-4) is communicated with the first air outlet pipe (19), and the sixth interface (21-6) is communicated with an air inlet of the gas chromatograph (20);

the communication state of the sampling device (21) is switched, so that the third interface (21-3), the second interface (21-2), the first quantitative ring (21-11), the fifth interface (21-5) and the fourth interface (21-4) can be communicated in sequence, or the first interface (21-1), the second interface (21-2), the first quantitative ring (21-11), the fifth interface (21-5) and the sixth interface (21-6) are communicated in sequence.

7. The photoelectrocatalytic reaction system according to claim 6, comprising a fourth gas flow switching device (23), wherein the fourth gas flow switching device (23) is provided with a thirteenth port (231), a fourteenth port (232), a fifteenth port (233) and a sixteenth port (234) which are switchable in communication, the thirteenth port (231) is in communication with the gas inlet end of the second backpressure valve (8), and the fourteenth port (232) is in communication with the gas outlet of the anode reactor (2);

the sampling device (21) is further provided with a seventh interface (21-7), an eighth interface (21-8), a ninth interface (21-9) and a tenth interface (21-10) which can be switched to be in a communication state, the seventh interface (21-7) is connected with a second quantitative ring (21-12), the other end of the second quantitative ring (21-12) is connected with the tenth interface (21-10), the eighth interface (21-8) is communicated with the sixteenth port (234), and the ninth interface (21-9) is communicated with the fifteenth port (233);

switching the communication state of the sampling device (21) to enable the ninth interface (21-9), the tenth interface (21-10), the second quantitative ring (21-12), the seventh interface (21-7) and the eighth interface (21-8) to be communicated in sequence; or the first interface (21-1), the tenth interface (21-10), the second quantitative ring (21-12), the seventh interface (21-7) and the sixth interface (21-6) are communicated in sequence;

switching the communication state of the fourth airflow switching device (23) may cause the thirteenth port (231) to communicate with the sixteenth port (234) and the fifteenth port (233) to communicate with the fourteenth port (232), or the thirteenth port (231) to communicate with the fourteenth port (232) and the fifteenth port (233) to communicate with the sixteenth port (234).

8. Photoelectrocatalytic reaction system according to any one of claims 1 to 7, wherein an ion exchange membrane for preventing products inside the cathode reactor (1) from entering the anode reactor (2) is interposed between the cathode reactor (1) and the anode reactor (2).

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