Membrane electrode electrolysis cell for electrochemical in-situ spectroscopy testing and applications

Abstract

The application belongs to the field of electrochemistry and spectroscopy, and particularly relates to a membrane electrode electrolytic cell for electrochemical in-situ spectroscopy measurement and application thereof. The electrolytic cell comprises a polymer membrane electrode as a working electrode, a cathode / anode catalyst for loading a target, and a top cover as a current collector of the working electrode, wherein a light transmission hole is arranged in the top cover for in-situ spectroscopy measurement and light transmission spectrum acquisition; a bottom plate as a current collector of the counter electrode, used for supporting the electrolytic cell and connecting with various spectroscopy test instruments; and a spacer used as a spacer between the top cover, the membrane electrode and the bottom cover connected in sequence, used for preventing short circuit. The application can realize various electrochemical in-situ spectroscopy measurements, including X-ray absorption spectroscopy test, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, Raman spectroscopy, attenuated total reflection infrared spectroscopy, differential mass spectroscopy and in-situ nuclear magnetic spectroscopy, and has wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electrochemistry and spectroscopy, and particularly relates to a membrane electrode electrolytic cell for electrochemical in-situ spectroscopy testing and application thereof. BACKGROUND

[0002] In order to achieve carbon dioxide emission reduction, the country vigorously promotes the popularization and application of renewable new energy such as solar energy and wind energy. However, these new energy sources have typical seasonality and time periodicity, and there are power supply peaks and troughs, so a large amount of electric energy cannot be effectively utilized, resulting in serious power abandonment and energy waste. The abandoned photovoltaic or wind power can be used to produce hydrogen gas (green hydrogen) through water electrolysis and storage, and then the energy can be utilized through hydrogen-oxygen fuel cells or hydrogen internal combustion engines, so that a new energy supply and demand cycle with zero carbon emission can be truly realized. The proton exchange membrane water (PEM) electrolysis technology is one of the most promising technologies for using renewable energy to generate electricity and producing hydrogen on a large scale.

[0003] Understanding and regulating the reaction mechanism and evolution mechanism of each interface of the PEM electrolysis device are the most powerful weapons for developing high-performance PEM electrolysis devices. However, the improvement of the understanding of the reaction mechanism depends on the development and application of advanced in-situ characterization technology, and under the working condition of the membrane electrode system, the chemical process, mass transfer mode and catalyst stability mechanism on the interface between the electrocatalyst and the polymer electrolyte may be completely different from the solid-liquid interface of the laboratory electrolyte system. Therefore, it is urgent to develop an in-situ spectroscopy and microscopy characterization technology based on solid-state electrolyte under working conditions, to reveal the chemical environment evolution of the electrocatalyst, the interface structure evolution law of the electrocatalyst and the PEM, and the failure mechanism. SUMMARY

[0004] The purpose of the present application is to provide a membrane electrode electrolytic cell that can be used for various electrochemical in-situ spectroscopy tests and application thereof.

[0005] The membrane electrode electrolytic cell provided by the present application can be used for various electrochemical in-situ spectroscopy tests, adopts a three-electrode or two-electrode system, the working electrode is a membrane electrode, which is similar to a tightly assembled electrolytic tank in actual industrialization, the type of the membrane can be replaced according to the test requirements, the in-situ electrolytic cell can tolerate corrosive electrolyte with a pH of 0-14, and can stably work under a pressure of 10 -7 -10 3 mbar, eliminates the electrolyte layer, has no liquid leakage problem, and can meet various in-situ spectroscopy tests in various in-situ environments such as normal temperature and pressure or high vacuum.

[0006] The membrane electrode electrolytic cell provided by the present application can be used for various electrochemical in-situ spectroscopy tests, and specifically comprises:

[0007] (1) polymer membrane electrode, used as working electrode, for loading target anode / cathode catalyst, where electrochemical reaction occurs, compressible membrane electrode can also play a role in fixing and sealing;

[0008] (2) top cover, mainly used as current collector of working electrode, with light transmission hole for in-situ spectroscopy test;

[0009] (3) bottom plate, mainly used as current collector of counter electrode, for supporting electrolytic cell and connecting with various spectroscopy test instruments;

[0010] (4) plastic gasket, top cover-membrane electrode-bottom cover are connected in sequence, and plastic gasket is added in between to prevent short circuit;

[0011] The polymer membrane electrode, top cover and bottom plate are fixed in sequence by plastic or nylon screws.

[0012] In the present application, the thickness of the membrane electrode is 20-400 μm, and the material is one of polyelectrolyte composite membrane, bipolar membrane, zwitterion exchange membrane, anion exchange membrane and cation exchange membrane.

[0013] Further, the amount of catalyst loaded on the polymer membrane electrode is 0.02-8 mg / cm 2 ; the specific loading method is:

[0014] (1) when the target sample is a thin film, the sample is loaded on the polymer membrane electrode by one or more of the following methods: magnetron sputtering, vacuum evaporation plating, arc ion plating, metal organic chemical vapor deposition, plasma enhanced chemical vapor deposition, laser chemical vapor deposition, liquid deposition, sol-gel method, hydrothermal method, hydrolysis deposition method and layer-by-layer self-assembly method;

[0015] (2) when the target sample is a powder, the sample is loaded on the polymer membrane electrode by one or more of the following methods: spraying, screen printing, blade coating and transfer printing.

[0016] In the present application, the thickness of the top cover and the bottom plate is 0.2-100 mm, wherein a circular or square light transmission hole with an aperture of 0.2-8 mm is arranged in the middle of the top cover, and the angle between the light transmission hole and the ground is 35-160 degrees; the material of the top cover and the bottom plate is one of titanium, copper, gold, silver, zinc, stainless steel, titanium alloy, aluminum alloy, aluminum-magnesium alloy, graphite sheet and glassy carbon sheet. In a preferred embodiment of the present application, titanium plate, glassy carbon sheet or graphite plate is used as the material of the top cover and the bottom plate.

[0017] Further, threaded holes are provided on the top cover and the bottom plate for fixing and assembling.

[0018] Further, the top cover and the bottom plate are provided with tab positions connected with the electrochemical workstation.

[0019] In the present application, the gasket and screw material is one or more of polyethylene, polytetrafluoroethylene, polyamide, polycarbonate, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polymethyl methacrylate, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polyamide, polycarbonate, polystyrene. In a preferred embodiment of the present application, the gasket and screw material is polytetrafluoroethylene.

[0020] The membrane electrode electrolysis cell of the present application can be used for electrochemical in-situ spectroscopy testing. Specifically, the membrane electrode electrolysis cell device is fixed on a spectroscopy instrument, the working electrode and the counter electrode are connected to an electrochemical workstation, and electrochemical in-situ spectroscopy testing is performed.

[0021] The electrochemical in-situ spectroscopy testing includes one or more of in-situ X-ray absorption spectroscopy testing, in-situ X-ray photoelectron spectroscopy, in-situ grazing incidence X-ray diffraction, in-situ X-ray emission spectroscopy, in-situ Raman spectroscopy, in-situ attenuated total reflection infrared spectroscopy, in-situ differential mass spectroscopy, and in-situ nuclear magnetic resonance.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) The membrane electrode system in-situ electrolysis cell provided by the present application has wide applicability, is simple and easy to obtain, has excellent universality and wide application prospect, and can be applied to electrochemical in-situ testing of various spectroscopies such as X-ray absorption spectroscopy testing, X-ray photoelectron spectroscopy, grazing incidence X-ray diffraction, Raman spectroscopy, attenuated total reflection infrared spectroscopy, differential mass spectroscopy, and nuclear magnetic resonance, thereby avoiding replacement and distinction verification between different devices;

[0024] (2) The membrane electrode system in-situ electrolysis cell provided by the present application helps to improve the quality of spectroscopy acquisition, and the design of canceling the liquid layer can effectively avoid the problem of serious interference of gas bubble overflow on real-time in-situ spectroscopy acquisition under the reaction system containing gas;

[0025] (3) The membrane electrode system in-situ electrolysis cell provided by the present application has high inclusiveness for applicable environment, and the design of the membrane electrode can be effectively sealed, and can work stably under a wide pressure window of 10 -7 -10 3 mbar, which truly overcomes the problem of electrochemical in-situ spectroscopy testing under ultra-high vacuum compared with the in-situ cell with liquid layer, and has obvious advantages especially in the case where the signal of aqueous solution itself interferes / obscures the spectroscopy results;

[0026] (4) Compared with the previous in-situ cell of solution system, the membrane electrode system in-situ electrolysis cell provided by the present application is closer to the working condition system of PEM electrolyte device, which is helpful for understanding and regulating the reaction mechanism and evolution mechanism of each interface of PEM electrolysis device, and is a powerful weapon for developing high-performance PEM electrolysis device. Attached Figure Description

[0027] Figure 1 Front view of the top cover / base of the electrolytic cell for in-situ spectroscopy of membrane electrodes.

[0028] Figure 2 Rear view of the top cover / base of the electrolytic cell for in-situ spectroscopy of membrane electrodes.

[0029] Figure 3 Side view of the top cover / base of the electrolytic cell for in-situ spectroscopy of membrane electrodes.

[0030] Figure 4 This is a schematic diagram of an electrolytic cell used for in-situ spectroscopic studies of membrane electrodes.

[0031] Figure 5 The volt-ampere curves are obtained from the electrolytic cell test during in-situ ultraviolet Raman spectroscopy acquisition (the dashed lines represent the points where the spectroscopy is constant).

[0032] Figure 6 In-situ ultraviolet Raman spectroscopy was performed using a membrane electrode electrochemical in-situ electrolytic cell. Spectra were obtained for the acidic water oxidation electrocatalyst under different applied voltages.

[0033] Figure 7 For Ir-TaO x The change in Ta-O coordination number (CN). Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0035] Example 1: An application of a membrane electrode electrolyzer for in-situ spectroscopic research: The evolution of the structure of an acidic water oxidation electrocatalyst is studied using in-situ electrochemical ultraviolet Raman spectroscopy.

[0036] (1) This embodiment discloses a membrane electrode electrolytic cell for in-situ electrochemical ultraviolet Raman spectroscopy. The materials of the electrolytic cell are: top cover – titanium plate; bottom cover – titanium plate; gasket and screws – polytetrafluoroethylene (PTFE). Figures 1-4 ).

[0037] (2) With Ir-TaO x Preparation of a polymer film electrode with Pt / C as the anode and Pt / C as the cathode.

[0038] 20 mg of Ir-TaO x The catalyst was added to a solution of isopropanol and water at a volume ratio of 5:1, and 200 μL of perfluorosulfonic acid resin monomer solution was added. 5wt% of the catalyst was added and sonicated for 1 hour to form a uniform ink; the same process was applied to the cathode. The anode and cathode catalyst slurries were then sprayed separately onto the cathode and cathode using an airbrush. 117 type perfluorosulfonic acid resin film on both sides of the film (the film needs to be treated with hydrogen peroxide, sulfuric acid, and deionized water in turn before use), and then hot-pressed at 60°C and 5MPa for 3min to prepare a polymer film working electrode.

[0039] (3) The above-mentioned film electrode is cut to the size suitable for the in-situ cell, preferably slightly larger than the top cover and the bottom plate to facilitate fixation and sealing. The film electrode is soaked in pure water, and then taken out and assembled in the order of plastic gasket-bottom plate-film electrode-top cover-plastic gasket to form the in-situ cell. The target catalyst to be measured of the film electrode is upward (top cover), and the in-situ cell is fixed and assembled by tightening the screw.

[0040] (4) The assembled in-situ cell is fixed to the sample stage of the Raman spectrum, the two tabs of the in-situ cell are connected to the electrochemical workstation through the terminal, and the light path, focusing and applied potential are adjusted, so that the structural evolution of the acidic water oxidation catalyst under different applied potentials can be realized. Figures 5-7 )。

[0041] The test results show that during the process of applying 0.8-2.0V cell voltage potential Figure 5 (dotted line is the constant potential value point for spectrum acquisition, covering the front, middle and rear of the OER reaction), the proportion of the Ir-TaO x sample TaO7 coordination configuration increases with the increase of the potential Figures 6-7 , Figure 7 , which shows that the Ta-O coordination number (CN) of Ir-TaO x changes with the increase of the potential. The CN value comes from the Ta-O stretching vibration peak intensity of the Raman peaks corresponding to TaO6 and TaO7. The increase of the Ta-O coordination number increases the number of O atoms around Ta. This result reveals that the increase of unstable coordination configuration and the over-oxidation of the carrier may be the reason for the deactivation of the catalyst in the long-term stability test.

[0042] Example 2, application of a membrane electrode electrolytic cell for in-situ spectroscopic study: use of in-situ grazing incidence X-ray diffraction to study the structural evolution of acidic water oxidation electrocatalyst.

[0043] (1) This example discloses a membrane electrode electrolytic cell for in-situ grazing incidence X-ray diffraction. The materials of the electrolytic cell are respectively: top cover-acrylic plate; bottom cover-acrylic plate; gasket-rubber pad; titanium felt-current collector.

[0044] (2) Preparation of a polymer membrane electrode with IrO2 as anode and Pt / C as cathode.

[0045] 20 mg of commercial IrO2 catalyst was added to a solution of isopropanol and water at a volume ratio of 5:1, and 200 μL of perfluorosulfonic acid resin monomer solution was added. 5wt% of the catalyst was added and sonicated for 1 hour to form a uniform ink; the same process was applied to the cathode. The anode and cathode catalyst slurries were then sprayed separately onto the cathode and cathode using an airbrush. The two sides of the 117 type perfluorosulfonic acid resin membrane (the membrane needs to be treated with hydrogen peroxide, sulfuric acid and deionized water in sequence before it can be used) are then hot-pressed together with the titanium felt at 60°C and 5 MPa for 3 minutes to prepare a polymer membrane working electrode containing a current collector.

[0046] (3) Assemble the in-situ cell in the following order: base plate - membrane electrode - top cover. The target catalyst of the membrane electrode should face upward (top cover). Tighten the screws to fix the in-situ cell in place.

[0047] (4) Fix the assembled in-situ cell onto the sample stage of grazing incidence X-ray diffraction, connect the two tabs of the in-situ cell to the electrochemical workstation through the wiring terminals, and adjust the optical path, focusing and external potential to realize the study of the structural evolution of acidic water oxidation catalyst under different external potentials.

[0048] Example 3 illustrates the application of membrane electrode electrolysis cells in the in-situ study of the structural evolution of electrocatalysts for water oxidation, including the preparation of polymer membrane electrodes for oxygen evolution reaction catalysts. The specific steps are as follows:

[0049] (1) The target catalysts and conductive agents at the anode and cathode are dispersed in a mixed solvent of water and organic solvent with added binder and ultrasonically dispersed; wherein the specific gravity of the binder in the slurry is 1-30wt%, and the binder is one or more of perfluorosulfonic acid polymer solution, polyvinylidene fluoride, polyacrylic acid, styrene-butadiene rubber, polyamide, polyvinyl alcohol, polyethyleneimine, and polyimide; the specific gravity of the conductive agent is 1-50wt%, and the type is one or more of conductive carbon black, conductive graphite, carbon fiber, carbon nanotube, and graphene.

[0050] (2) A uniformly dispersed catalyst slurry is sprayed onto the surface of polytetrafluoroethylene and transferred onto the membrane, or directly sprayed onto the surface of the polymer membrane, to obtain a polymer membrane electrode with target catalysts for both the anode and cathode loaded on both sides; the loading of the anode / cathode catalyst is 0.02-8 mg / cm³. 2 ;

[0051] (3) Cut the prepared membrane electrode to a suitable size and assemble it into the electrochemical in-situ spectrophotometer electrolytic cell;

[0052] (4) Fix the assembled in-situ cell on the in-situ X-ray absorption spectroscopy, in-situ X-ray photoelectron spectroscopy, in-situ grazing incidence X-ray diffraction, in-situ X-ray emission spectroscopy, in-situ Raman spectroscopy, in-situ attenuated total reflection infrared spectroscopy, in-situ differential mass spectroscopy, in-situ nuclear magnetic resonance test bench, and perform vacuum treatment as needed for the vacuum required;

[0053] (5) Connect the in-situ cell to the electrochemical work station, adjust the light path, apply potential, and in-situ spectroscopy testing of the electrocatalytic water oxidation reaction catalyst can be performed.

Claims

1. A membrane electrode electrolytic cell for in-situ electrochemical spectroscopic testing, characterized in that, include: (1) Polymer membrane electrode, used as working electrode, for loading the target cathode / anode catalyst, is the site where the electrochemical reaction occurs. The compressible polymer membrane electrode is used for both fixation and sealing. (2) Top cover, used as a current collector for the working electrode, equipped with a light-transmitting hole for in-situ spectroscopic testing; (3) Base plate, used as a current collector for the counter electrode, for supporting the electrolytic cell and for connecting to various spectroscopic testing instruments; (4) Plastic gasket, used as an isolation gasket between the top cover-membrane electrode-bottom cover in sequence connection, to prevent short circuit; The polymer film electrode, top cover, and bottom plate are sequentially bolted together with screws made of insulating material. The polymer membrane electrode has a thickness of 20-400 μm and is made of one of the following materials: polyelectrolyte composite membrane, bipolar membrane, zwitterion exchange membrane, anion exchange membrane, or cation exchange resin membrane.

2. The membrane electrode electrolyzer according to claim 1, characterized in that, The amount of catalyst loaded on the polymer membrane electrode is 0.02-8 mg / cm³. 2 .

3. The membrane electrode electrolyzer according to claim 1, characterized in that, The top cover has a thickness of 0.2-100 mm and a circular or square light-transmitting hole with a diameter of 0.2-8 mm is provided in the center. The chamfer angle between the light-transmitting hole and the ground is 35-160 degrees. o The top cover is made of one of the following materials: titanium, copper, gold, silver, zinc, stainless steel, titanium alloy, aluminum alloy, graphite sheet, or glass carbon sheet.

4. The membrane electrode electrolyzer according to claim 1, characterized in that, The base plate has a thickness of 0.2-100 mm and is made of one of the following materials: titanium, copper, gold, silver, zinc, stainless steel, titanium alloy, aluminum alloy, aluminum-magnesium alloy, graphite sheet, or glassy carbon sheet. The base plate is equipped with screw fixing holes as needed for fixing to different spectrometers.

5. The membrane electrode electrolytic cell according to claim 1, characterized in that, The gaskets and screws are made of one or more of the following materials: polyethylene, polytetrafluoroethylene, polynylon, polycarbonate, polypropylene, polyvinyl chloride, polyvinylidene fluoride, polymethyl methacrylate, ethylene-vinyl acetate copolymer, polyethylene terephthalate, and polystyrene.

6. The application of the membrane electrode electrolytic cell as described in any one of claims 1-5 in in-situ electrochemical spectroscopic testing, characterized in that, Specifically, the membrane electrode electrolytic cell is fixed on the spectroscopic instrument; the working electrode and the counter electrode are connected to the electrochemical workstation, and in-situ electrochemical spectroscopic tests are performed.

7. The application according to claim 6, characterized in that, Electrochemical in-situ spectroscopic tests include one or more of the following: in-situ X-ray absorption spectroscopy, in-situ X-ray photoelectron spectroscopy, in-situ grazing incidence X-ray diffraction, in-situ X-ray emission spectroscopy, in-situ Raman spectroscopy, in-situ attenuated total reflection infrared spectroscopy, in-situ differential mass spectrometry, and in-situ nuclear magnetic resonance.

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