An electrocatalytic in-situ Mössbauer spectroscopy sample cell and its application

Abstract

The present application discloses an electrocatalytic in-situ Mössbauer spectroscopy sample cell and its application; the electrocatalytic in-situ Mössbauer spectroscopy sample cell includes a proton exchange membrane, a working electrode cell cavity, and a counter electrode cell cavity; the working electrode cell cavity is horizontally fixedly connected to the counter electrode cell cavity; a through hole is provided on the cavity wall connecting the working electrode cell cavity and the counter electrode cell cavity; a concave groove is provided at the through hole, and the proton exchange membrane is located in the concave groove. The working electrode is perpendicular to the radiation source. Due to the different positions of the radiation source, two sample cells with different orientations are designed. The electrolytic cell can avoid the interference caused by the oxygen evolution reaction of the counter electrode and can better obtain the real reaction state of the catalyst; it is suitable for Mössbauer spectroscopy devices of different elements (Fe / Sn); it can also be applied to different electrocatalytic reactions (CO2 / N2 reduction reaction).

Description

Technical Field

[0001] The present application relates to an electrocatalytic in-situ Mössbauer spectroscopy sample cell and its application, belonging to the technical field of electrochemical catalysis. Background Art

[0002] Iron- and tin-based catalysts play a crucial role in electrocatalysis. The introduction of various high-resolution in situ spectroscopic methods can clarify the catalyst's true structure, monitor its dynamic reaction processes, and elucidate its catalytic reaction mechanisms, making them key to guiding the development of high-performance catalysts. In situ X-ray diffraction (XAS) is one of the most important techniques for identifying the electronic and coordination structures of catalytic sites. However, due to the complexity of catalytic reactions and heterogeneous catalyst systems, in situ X-ray diffraction (XAS) typically only provides average information on the structure and valence state of the catalytic center.

[0003] Mössbauer spectroscopy has an extremely high energy resolution, allowing quantitative analysis of the coordination structure, spin state, and valence state of the active centers of iron / tin-based catalysts. Leveraging the advantages of in-situ Mössbauer spectroscopy, dynamic reaction processes can be monitored and reaction pathways optimized, providing guidance for the development of high-performance catalysts.

[0004] Therefore, the design of a suitable in-situ cell is crucial. The designed in-situ cell needs to restore the actual reaction state of the catalyst as much as possible and reduce the attenuation of γ rays. Summary of the Invention

[0005] The present invention aims to provide an H-type electrocatalytic in-situ Mössbauer spectroscopy sample cell, which avoids the influence of the oxygen evolution reaction at the anode, is suitable for light sources with different orientations and different elements (Fe / Sn), and is also suitable for different electrocatalytic reactions (CO2 / N2 reduction) at room temperature and pressure.

[0006] In one aspect of the present application, an electrocatalytic in-situ Mössbauer spectroscopy sample cell is provided, wherein the electrocatalytic in-situ Mössbauer spectroscopy sample cell comprises a proton exchange membrane, a working electrode cell cavity, and a counter electrode cell cavity;

[0007] The working electrode cell cavity is horizontally fixedly connected to the counter electrode cell cavity;

[0008] A through hole is provided on the cavity wall connecting the working electrode cell cavity and the counter electrode cell cavity;

[0009] A concave groove is provided at the through hole, and the proton exchange membrane is located in the concave groove.

[0010] Optionally, the electrocatalytic in-situ Mössbauer spectroscopy sample cell further includes a sealing ring located in the concave groove, and both sides of the proton exchange membrane are fixed by gaskets.

[0011] Optionally, the working electrode cell cavity is provided with an electrolyte, a working electrode, a reference electrode, and an air guide tube;

[0012] The working electrode, reference electrode, and gas guide tube are all located below the liquid level of the electrolyte;

[0013] The counter electrode cell cavity is provided with an electrolyte and a counter electrode;

[0014] The counter electrode is located below the liquid surface of the electrolyte.

[0015] All electrodes are connected to the electrochemical workstation through wires. The upper part of the working electrode is wrapped with conductive copper tape and then connected to the electrode clamp.

[0016] Optionally, the working electrode cell cavity includes an upper end cover 1; the upper end cover 1 is provided with a plurality of through holes for installing a reference electrode, a counter electrode and an air guide tube;

[0017] The counter electrode cell cavity includes an upper end cover II, and the upper end cover II is provided with a mounting hole for mounting the counter electrode;

[0018] The outer side of the counter electrode pool cavity is provided with a through hole extending to the inner side of the working electrode pool cavity, which is used to fix the counter electrode pool cavity and the working electrode pool cavity;

[0019] Or a through hole is opened on the side of the working electrode cell cavity and extends to the inner side of the counter electrode cell cavity, which is used to fix the counter electrode cell and the working electrode cell.

[0020] Optionally, a through hole with a thread is opened on the side of the working electrode pool or the counter electrode pool cavity, and the working electrode pool is connected to the counter electrode pool by the thread and the matching screws.

[0021] Optionally, a blind hole is provided on the cavity wall of the working electrode cell cavity, which serves as the light source illumination area.

[0022] The working electrodes are located close to the blind holes in the working electrode cell.

[0023] Optionally, when the blind hole is provided on the outer end surface of the lower cavity wall of the working electrode cell cavity:

[0024] The working electrode cell cavity includes an upper end cover I; the upper end cover is provided with a threaded hole for mounting a gas-liquid ratio control knob and a gas-liquid ratio control knob adapted to the threaded hole;

[0025] The blind hole and the threaded hole are located at the same axial position.

[0026] The gas-liquid ratio control knob can adjust the height, get as close to the working electrode as possible and fix the working electrode, reduce the liquid between the electrode and the knob, and reduce the attenuation of gamma rays in the liquid.

[0027] Optionally, the working electrode is located on the inner end surface of the lower cavity wall, adapted to the position of the blind hole, and perpendicular to the light path of the light source.

[0028] Optionally, when the blind hole is provided on the outer wall of the working electrode cell cavity:

[0029] The working electrode is located in the working electrode cell cavity and is perpendicular to the light path irradiated by the light source;

[0030] A through hole is provided in the middle and upper part of the counter cell cavity, so that the gamma rays do not need to pass through the liquid when passing through the counter electrode pool, thereby reducing the weakening of the gamma rays by the liquid;

[0031] The through hole is adapted to the blind hole.

[0032] Optionally, the reference electrode is selected from at least one of a saturated calomel electrode and a saturated silver / silver chloride electrode;

[0033] The counter electrode is selected from one of a platinum sheet, a platinum wire, a platinum mesh, and a carbon rod.

[0034] Optionally, the cavity material of the electrocatalytic in-situ Mössbauer spectroscopy sample cell is selected from at least one of polymer materials polyetheretherketone, polytetrafluoroethylene, nylon, and organic glass.

[0035] Another aspect of the present application provides a use of the above-mentioned electrocatalytic in-situ Mössbauer spectroscopy sample cell in an electrocatalytic reaction, characterized in that the electrocatalytic reaction includes at least one of a carbon dioxide reduction reaction and a nitrogen reduction reaction.

[0036] The beneficial effects of this application include:

[0037] The H-type electrocatalytic in-situ Mössbauer spectroscopy sample cell of the present invention is simple to disassemble and easy to operate.

[0038] This in-situ cell features a separate working electrode cell and counter electrode cell, eliminating the influence of the counter electrode oxygen evolution reaction. During the reaction, gas-liquid two-phase flow and proton migration occur, simulating real-world reaction conditions. During the reaction, the gas-liquid ratio adjustment knob in the counter electrode cell significantly reduces the thickness of the liquid layer on the catalyst surface. The blind hole on the outside of the cell also reduces the thickness of the cavity through which gamma rays pass, reducing gamma ray attenuation and thus shortening test time. It is also compatible with different light source elements and light sources from different directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a design diagram of the in-situ spectroscopy cell with the blind hole located at the bottom of the sample cell in Example 1.

[0040] Figure 2This is a cross-sectional view of the in-situ Mus Spectroscopy cell in Example 1, where the blind hole is located at the bottom of the sample cell.

[0041] Figure 3 This is a real picture of the in-situ spectroscopy cell with the blind hole located at the bottom of the sample cell in Example 1.

[0042] Figure 4 This is the design diagram of the in-situ spectroscopy cell with the blind hole located at the bottom of the sample cell in Example 2.

[0043] Figure 5 This is a cross-sectional view of the in-situ Mus Spectroscopy cell in Example 2, where the blind hole is located at the bottom of the sample cell.

[0044] Figure 6 A photo of the in-situ Mus Spectroscopy cell with a blind hole located at the bottom of the sample cell in Example 2

[0045] in:

[0046] 1. Working electrode cell I; 2. Counter electrode cell I; 3. Gas-liquid ratio adjustment knob; 4. Blind hole I; 5. Circular groove; 6. Working electrode cell II; 7. Counter electrode cell II; 8. Blind hole II; 9. Press block; 10. Proton exchange membrane. DETAILED DESCRIPTION

[0047] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0048] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0049] Example 1

[0050] In situ Mössbauer spectroscopy monitoring of electrocatalytic CO2 reduction (vertical)

[0051] Reference Figures 1 to 3 As shown, the one with the gas-liquid ratio adjustment knob is the working electrode cell, and the one without is the counter electrode cell. The working electrode is inserted through the gap between the working electrode cell's top cover and the chamber, and is located directly below the gas-liquid ratio adjustment knob. The reference electrode and gas tube are inserted vertically through the smaller through-hole on the top cover of the working electrode cell until they are below the electrolyte level. The counter electrode is inserted vertically through the smaller through-hole on the top cover of the counter electrode cell.

[0052] The specific design method is as follows:

[0053] (1) Cavity: The material selected is polyetheretherketone with good stability, high temperature resistance, electrolyte resistance, certain mechanical strength and light transmittance.

[0054] (2) Internal cavity of the cavity: The top cover of the cavity is provided with a through hole for fixing the reference electrode, the counter electrode and the gas guide tube. The through hole with internal thread on the working electrode pool I1 is screwed with the gas-liquid ratio adjustment knob 3 with external thread for fixing the working electrode. A blind hole I4 is provided at the bottom of the working electrode pool to shorten the thickness of the cavity that the radiation needs to pass through. A through hole with internal thread is provided on the side of the counter electrode pool I2, extending to the side of the working electrode pool and fixed by screws.

[0055] (3) The sealing gasket is located in a circular groove 5 formed inside the cavity where the working electrode cell and the counter electrode cell are combined.

[0056] (4) The proton exchange membrane 10 is located between the two sealing gaskets.

[0057] (5) One side of the working electrode is coated with 5mg / cm 2 The catalyst is applied in a circular shape, which is consistent with the size of the gas-liquid ratio adjustment knob above the working electrode and the blind hole opened in the cavity below.

[0058] (6) The catalyst-coated side of the working electrode faces upward, and the uncoated side is placed against the bottom of the chamber. Wrap the conductive copper tape around the upper middle portion, moving it out through the gap between the working electrode cell cover and the chamber, and connect the electrode clamp to the electrochemical workstation.

[0059] (7) The saturated calomel electrode is inserted vertically through the hole above the working electrode cell to below the electrolyte surface. The platinum sheet is inserted vertically through the hole above the counter electrode cell to below the electrolyte surface. The gas tube is inserted through the hole above the top cover of the working electrode cell to below the electrolyte surface, close to the catalyst-coated side of the working electrode.

[0060] (8) The gamma rays involved in in-situ Mössbauer spectroscopy are irradiated from bottom to top below the blind hole opened in the working electrode cell.

[0061] Change the applied potential and record the corresponding spectrum signal.

[0062] Example 2

[0063] In situ Mössbauer spectroscopy monitoring of electrocatalytic CO2 reduction.

[0064] Reference Figures 4-6 As shown, refer to Figure 5 In the embodiment, the counter electrode pool II7, the working electrode pool II6, the working electrode, the reference electrode and the gas guide tube are vertically inserted from the through hole above the top cover of the working electrode pool until they are below the electrolyte level. The counter electrode is located in the counter electrode pool.

[0065] The specific design method is as follows:

[0066] (1) Cavity: The material selected is polytetrafluoroethylene with good stability, high temperature resistance, electrolyte resistance, certain mechanical strength and light transmittance.

[0067] (2) Internal cavity: The top cover of the cavity is provided with a through hole for fixing the reference electrode, working electrode, and gas duct. A through hole is provided in the upper middle portion of the counter electrode cell II7, and a blind hole II8 is provided on the outer side of the working electrode cell II6 to shorten the cavity thickness required for the radiation to pass through. A through hole with an internal thread is provided on the side of the counter electrode cell, extending to the side of the working electrode cell and fixed by screws.

[0068] (3) The sealing gasket is located in a circular groove 5 formed inside the cavity where the working electrode cell and the counter electrode cell are combined. A compression block 9 is located in the lower middle portion of the counter electrode cell and is used to compress the sealing gasket. The proton exchange membrane 10 is located between the two sealing gaskets.

[0069] (4) One side of the working electrode is coated with 5mg / cm 2 The catalyst is coated in a circular shape, which is consistent in size with the through hole opened in the upper part of the counter electrode cell and the blind hole opened in the upper part of the working electrode cell.

[0070] (6) The catalyst-coated side of the working electrode faces left, and the uncoated side is placed against the corresponding position of the blind hole on the right side of the working electrode cell. Wrap the conductive copper tape around the upper middle part and connect the electrode clamp to the electrochemical workstation.

[0071] (7) A saturated calomel electrode is inserted vertically through the hole above the working electrode cell until it is below the electrolyte level. A platinum sheet is inserted from above the counter electrode cell until it is below the electrolyte level. A gas tube is inserted from the hole above the top cover of the working electrode cell until it is below the electrolyte level, close to the catalyst-coated side of the working electrode.

[0072] (8) The gamma rays involved in in-situ Mössbauer spectroscopy pass through the sample cell from right to left on the right side of the blind hole opened in the working electrode cell.

[0073] Change the applied potential and record the corresponding spectrum signal.

[0074] This patent can be used for 57 Fe, 119 The electrocatalytic reactions related to elements such as Sn, such as carbon dioxide reduction and nitrogen reduction reactions, overcome the influence of the oxygen evolution reaction on the electrode in the previous in-situ cell, and are suitable for light sources in different directions, which can reflect the catalyst in the reaction process. 57 Fe, 119 The real dynamic changes of Sn's valence, coordination, and spin states.

[0075] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An electrocatalytic in-situ Mössbauer spectroscopy sample cell, characterized in that: The electrocatalytic in-situ Mössbauer spectroscopy sample cell comprises a proton exchange membrane, a working electrode cell cavity, and a counter electrode cell cavity; The working electrode cell cavity is horizontally fixedly connected to the counter electrode cell cavity; A through hole is provided on the cavity wall connecting the working electrode cell cavity and the counter electrode cell cavity; A concave groove is provided at the through hole, and the proton exchange membrane is located in the concave groove.

2. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 1, characterized in that: The electrocatalytic in-situ Mössbauer spectroscopy sample cell further comprises a sealing ring located in the concave groove, and both sides of the proton exchange membrane are fixed by gaskets.

3. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 1, characterized in that: The working electrode cell cavity is provided with an electrolyte, a working electrode, a reference electrode, and an air guide tube; The working electrode, reference electrode, and gas guide tube are all located below the liquid level of the electrolyte; The counter electrode cell cavity is provided with an electrolyte and a counter electrode; The counter electrode is located below the liquid surface of the electrolyte.

4. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 1, characterized in that: The working electrode cell cavity includes an upper end cover 1; the upper end cover 1 is provided with a plurality of through holes for installing a reference electrode, a counter electrode and an air guide tube; The counter electrode cell cavity includes an upper end cover II, and the upper end cover II is provided with a mounting hole for mounting the counter electrode; The outer side of the counter electrode pool cavity is provided with a through hole extending to the inner side of the working electrode pool cavity, which is used to fix the counter electrode pool cavity and the working electrode pool cavity; Or a through hole extending to the inner side of the counter electrode pool is opened on the side of the working electrode pool, which is used to fix the counter electrode pool and the working electrode pool.

5. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 4, characterized in that: A blind hole is provided on the cavity wall of the working electrode cell cavity, which serves as the light source illumination area.

6. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 5, characterized in that: When the blind hole is provided on the outer end surface of the lower cavity wall of the working electrode cell cavity: The working electrode cell cavity includes an upper end cover I; the upper end cover is provided with a threaded hole for mounting a gas-liquid ratio control knob and a gas-liquid ratio control knob adapted to the threaded hole; The blind hole and the threaded hole are located at the same axial position.

7. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 6, characterized in that: The working electrode is located on the inner end surface of the lower cavity wall, adapted to the position of the blind hole, and perpendicular to the light path of the light source.

8. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 5, characterized in that: When the blind hole is provided on the outer wall of the working electrode cell cavity: The working electrode is located in the working electrode cell cavity and is perpendicular to the light path irradiated by the light source; A through hole is provided in the middle and upper part of the counter electrode cell cavity; The through hole is adapted to the blind hole.

9. The electrocatalytic in-situ Mössbauer spectroscopy sample cell according to claim 3, characterized in that: The reference electrode is selected from at least one of a saturated calomel electrode and a saturated silver / silver chloride electrode; The counter electrode is selected from one of a platinum sheet, a platinum wire, a platinum mesh, and a carbon rod; The cavity material of the electrocatalytic in-situ Mössbauer spectroscopy sample cell is selected from at least one of the polymer materials polyetheretherketone, polytetrafluoroethylene, nylon, and organic glass.

10. Use of the electrocatalytic in-situ Mössbauer spectroscopy sample cell according to any one of claims 1 to 9 in an electrocatalytic reaction, characterized in that: The electrocatalytic reaction includes at least one of a carbon dioxide reduction reaction and a nitrogen reduction reaction.

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