Ruthenium-germanium heterogeneous phase intermetallic compound as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of heterogeneous phase intermetallic compounds, and discloses a ruthenium-germanium heterogeneous phase intermetallic compound and a preparation method and application thereof. The preparation method comprises the following steps: step 1, dissolving Ge precursor salt, Ru precursor salt and a carrier material in a water-soluble polymer solution; the mmol ratio of the Ru precursor salt to the Ge precursor salt is 0.05: (0.05-0.09); step 2, performing freeze drying treatment on a product in the step 1; 3, performing high-temperature heat treatment on the product obtained in the step 2 in a reducing atmosphere at the temperature of 800-1000 DEG C, and preparing the ruthenium-germanium heterogeneous phase intermetallic compound after the high-temperature heat treatment; according to the ruthenium-germanium heterogeneous phase intermetallic compound prepared through the preparation method, the ruthenium-germanium heterogeneous phase can be obviously observed through a spherical aberration electron microscope, the synergistic effect is generated through strong interaction among different components, the physical and chemical properties of the material can be obviously optimized, and when the ruthenium-germanium heterogeneous phase intermetallic compound is used as a catalyst, the catalytic effect is extremely good.

Description

Technical Field

[0001] The present invention belongs to the technical field of heterogeneous phase intermetallic compounds, and in particular relates to a ruthenium-germanium heterogeneous phase intermetallic compound and a preparation method and application thereof. Background Art

[0002] In recent years, intermetallic compounds have been widely used in the field of catalysis. Compared with single metals or binary solid solution alloys, their ordered atomic arrangement and uniformly distributed active sites effectively enhance the bonding strength between different metal atoms. This structural feature not only effectively solves the problem of easy solubility of non-noble metal atoms in solid solution alloys, but also significantly optimizes the adsorption and desorption process of reactants on the catalyst surface, thereby improving catalytic activity and increasing the service life of the catalyst. Generally speaking, the composition of intermetallic compounds must contain elemental components with catalytic activity. These active centers are usually composed of noble metal elements (such as Pd, Pt, Au, Ru, Rh, Ir, etc.) or transition metal elements. In addition, the range of elements selected as the second component is relatively wide, mainly including semiconductors and their adjacent elements (such as Ga, Ge, Sb, Sn, etc.) and pre-transition metal elements.

[0003] Ruthenium-germanium-based intermetallic compounds are one type of noble metal-based intermetallic compounds and have been widely used in the field of catalysts. Theoretically, regulating their crystal phases can adjust the configuration of catalytic active sites and construct high activity on non-equilibrium metal surfaces, ultimately optimizing catalytic performance. However, due to the unsaturated and non-directional characteristics of metallic bonds, noble metals tend to crystallize in highly symmetrical and tightly packed structures (i.e., hexagonal close packing and face-centered cubic structures), which means that each noble metal has only one thermodynamically stable crystal phase at room temperature, and regulating their crystal phases is extremely difficult. Therefore, constructing heterogeneous phase ruthenium-germanium-based intermetallic compounds is a more feasible strategy. By forming heterogeneous phases, the strong interactions between different components are utilized to produce synergistic effects, so that the physical and chemical properties of the material can be optimized. In addition, the phase interfaces in ruthenium-germanium-based heterogeneous phase intermetallic compounds can serve as active sites to promote the adsorption and desorption of key intermediates. However, in the prior art, especially in nano-sized catalyst materials, due to the large lattice mismatch between different crystal phases, it is difficult to construct ruthenium-germanium-based heterogeneous phase intermetallic compounds by precisely regulating phase transitions.

[0004] Based on this, the technical problem that needs to be solved in this case is: to provide a method for preparing ruthenium-germanium heterogeneous phase intermetallic compounds. Summary of the Invention

[0005] The object of the present invention is to provide a method for preparing a ruthenium-germanium heterophase intermetallic compound. The ruthenium-germanium heterophase intermetallic compound prepared by the preparation method of the present invention can clearly observe the ruthenium-germanium heterogeneous phase through spherical aberration electron microscopy. The strong interaction between different components is used to produce a synergistic effect, so that the physical and chemical properties of the material can be significantly optimized. When used as a catalyst, the catalytic effect is excellent.

[0006] At the same time, the invention also discloses a ruthenium-germanium heterogeneous phase intermetallic compound obtained by the preparation method and its application.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] A method for preparing a ruthenium-germanium heterogeneous phase intermetallic compound comprises the following steps:

[0009] Step 1: dissolving a Ge precursor salt, a Ru precursor salt, and a support material in a water-soluble polymer solution; the millimolar ratio of the Ru precursor salt to the Ge precursor salt is 0.05:0.05-0.09;

[0010] Step 2: freeze-drying the product of step 1;

[0011] Step 3: subjecting the product obtained in step 2 to high-temperature heat treatment at a temperature of 800-1000° C. in a reducing atmosphere to obtain a ruthenium-germanium heterogeneous intermetallic compound.

[0012] Preferably, the Ge precursor salt in step 1 is (NH4)2GeF6; and the Ru precursor salt is Ru(NO)(NO3)3.

[0013] Preferably, the carrier material described in step 1 is a surface-modified carrier material, which is at least one of graphene oxide, carbon nanotubes, and Ketjen black.

[0014] Preferably, the water-soluble polymer in the water-soluble polymer solution in step 1 is at least one of polyvinyl alcohol, polyacrylic acid or polyacrylamide; and the concentration of the water-soluble polymer solution is 15-25 mg / mL.

[0015] Preferably, the millimolar ratio of the Ge precursor salt to the Ru precursor salt is 0.05:0.075-0.08.

[0016] More preferably, the carrier material is carbon nanotubes, and the water-soluble polymer in the water-soluble polymer solution is polyacrylamide.

[0017] Preferably, the reducing atmosphere in step 3 is an argon-hydrogen mixed atmosphere, and the volume ratio of argon to hydrogen is 85-92:8-15; the freeze-drying temperature in step 2 is -10°C to -45°C, and the drying time is 20-40h; the heating rate of the high-temperature heat treatment in step 3 is 2-10°C / min, and the holding time is 5-10h.

[0018] In addition, the present invention provides a ruthenium-germanium heterogeneous phase intermetallic compound, which is prepared by the preparation method described above.

[0019] Finally, the present invention also discloses the use of the ruthenium-germanium heterogeneous intermetallic compound as described above to prepare a catalyst.

[0020] The beneficial effects of the present invention are:

[0021] The ruthenium-germanium heterogeneous intermetallic compound prepared by the preparation method of the present invention can clearly observe the ruthenium-germanium heterogeneous phase through spherical aberration electron microscopy. It utilizes the strong interaction between different components to produce a synergistic effect, so that the physical and chemical properties of the material can be significantly optimized. When used as a catalyst, it has an excellent catalytic effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a spherical aberration electron microscope image of the ruthenium-germanium heterophase intermetallic compound of Example 4;

[0023] Figure 2 HER performance diagram of various ruthenium-germanium heterophase intermetallic compounds. DETAILED DESCRIPTION

[0024] Below in conjunction with embodiments of the present invention, technical scheme of the present invention is clearly and completely described, obviously, described embodiment is only a part of embodiment of the present invention, rather than whole embodiment. Based on the embodiment in the present invention, those of ordinary skill in the art, without making the every other embodiment obtained under creative work premise, all fall within the scope of protection of the present invention. It should be noted that, in the embodiment, those not indicating specific conditions, carry out according to the condition of normal condition or manufacturer's suggestion. Reagents used or instrument not indicating manufacturer, all are conventional products that can be obtained by commercial purchase.

[0025] Product Information:

[0026] Ruthenium(III) nitrosyl nitrate (Ru(NO)(NO3)3, 1.5% w / v) was purchased from Maclean;

[0027] Ammonium hexafluorogermanate ((NH4)2GeF6) was purchased from Aladdin;

[0028] Graphene oxide was purchased from Nanjing Xianfeng Nanomaterial Technology Co., Ltd.;

[0029] Multi-walled carbon nanotubes were purchased from Aladdin;

[0030] Ketjen Black EC300J was purchased from Suzhou Shengerno Technology Co., Ltd.

[0031] Example 1

[0032] Step 1: Dissolve 0.05 mmol (NH4)2GeF6, 0.05 mmol Ru(NO)(NO3)3, and 20 mg carbon nanotubes in 5 mL of 20 mg / mL polyacrylamide solution;

[0033] Step 2: The solution in step 1 was ultrasonicated for 1 hour to prepare a hydrogel, and the hydrogel was freeze-dried to remove moisture; the freeze-drying temperature was -20°C and the drying time was 30 hours;

[0034] Step 3: The product obtained in step 2 is subjected to high-temperature heat treatment in an argon-hydrogen mixed atmosphere at a temperature of 900°C, a heating rate of 6°C / min, a holding time of 13 hours, and a volume ratio of argon to hydrogen of 90:10; after the holding is completed, it is cooled to 25°C to obtain a ruthenium-germanium heterogeneous metal compound.

[0035] Example 2

[0036] It is generally the same as Example 1, except that in step 1, the amount of (NH4)2GeF6 used is 0.05 mmol, and the amount of Ru(NO)(NO3)3 used is 0.065 mmol.

[0037] Example 3

[0038] It is generally the same as Example 1, except that in step 1, the amount of (NH4)2GeF6 used is 0.05 mmol, and the amount of Ru(NO)(NO3)3 used is 0.075 mmol.

[0039] Example 4

[0040] It is substantially the same as Example 1, except that in step 1, the amount of (NH4)2GeF6 used is 0.05 mmol, and the amount of Ru(NO)(NO3)3 used is 0.08 mmol.

[0041] Example 5

[0042] It is generally the same as Example 1, except that in step 1, the amount of (NH4)2GeF6 used is 0.05 mmol, and the amount of Ru(NO)(NO3)3 used is 0.09 mmol.

[0043] Example 6

[0044] The process is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced by graphene oxide.

[0045] Example 7

[0046] The process is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced with Ketjen black.

[0047] Example 8

[0048] The process is substantially the same as Example 1, except that the polyacrylamide in step 1 is replaced by polyvinyl alcohol.

[0049] Example 9

[0050] The process is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced by graphene oxide, and the polyacrylamide is replaced by polyvinyl alcohol.

[0051] Example 10

[0052] The process is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced by Ketjen black, and the polyacrylamide is replaced by polyvinyl alcohol.

[0053] Example 11

[0054] The process is substantially the same as Example 1, except that the polyacrylamide in step 1 is replaced by polyacrylic acid.

[0055] Example 12

[0056] The process is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced by graphene oxide, and the polyacrylamide is replaced by polyacrylic acid.

[0057] Example 13

[0058] The method is substantially the same as Example 1, except that the carbon nanotubes in step 1 are replaced by Ketjen black, and the polyacrylamide is replaced by polyacrylic acid.

[0059] The raw material combination formula table in each embodiment is shown in Table 1;

[0060] Table 1 Recipe

[0061]

[0062]

[0063] Performance testing

[0064] The spherical aberration electron microscope image of the ruthenium-germanium heterogeneous phase metal compound of Example 4 is as follows: Figure 1 As shown, Figure 1 The Ru-Ge heterogeneous phase can be clearly observed.

[0065] Electrochemical hydrogen evolution performance test method

[0066] The electrochemical performance of all electrocatalysts was tested at room temperature using a CHI 760E electrochemical workstation (Shanghai Chenhua) using a conventional three-electrode system. The electrolyte was an argon-saturated 1.0 M KOH solution. 2 ), graphite rods, and Hg / HgO electrodes were used as working, counter, and reference electrodes, respectively. The catalyst ink was prepared by dispersing 6 mg of the prepared catalyst in a mixed solvent of ethanol (640 μL), water (320 μL), and Nafion solution (40 μL, 5 wt.%) and ultrasonically treating the mixture to obtain a uniform solution. All potentials were measured using a reversible hydrogen electrode (RHE) according to the formula E RHE =E Hg / HgO The polarization curves were calibrated with a pH of +0.098+0.0591×pH, and iR compensation was performed on all polarization curves. The hydrogen evolution reaction (HER) performance was investigated by scanning at a rate of 5 mV s -1 The linear sweep voltammetry (LSV) curve evaluation of the results is referenced Figure 2 And Table 2, Figure 2 Figure 2 is the HER performance diagram of various ruthenium-germanium heterogeneous intermetallic compounds. At the same current density, the lower the required overpotential, the better the hydrogen evolution performance.

[0067] Table 2 Passing point data table

[0068]

[0069]

[0070] The data analysis of Table 2 shows that the ruthenium-germanium heterogeneous metal compound prepared by the technical solution of the present invention has a high conductivity at a current of 1000 mA cm -2 When the voltage drop is less than 300mV, it shows that it has excellent hydrogen evolution performance. When it is used as a catalyst, the catalytic effect is excellent.

[0071] In addition, the products of Example 3 and Example 4 were -2 When the transition point is 0.05:0.075-0.08, the carrier material is carbon nanotubes, and the water-soluble polymer material is polyacrylamide, the hydrogen evolution performance of the prepared ruthenium-germanium heterogeneous metal compound is further improved.

[0072] In summary, the ruthenium-germanium heterogeneous intermetallic compound prepared by the present invention forms a heterogeneous phase and utilizes the strong interaction between different components to produce a synergistic effect, so that the physical and chemical properties of the material can be significantly optimized.

[0073] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A method for preparing a ruthenium-germanium heterogeneous intermetallic compound, characterized in that: The specific steps include: Step 1: dissolving a Ge precursor salt, a Ru precursor salt, and a support material in a water-soluble polymer solution; the millimolar ratio of the Ru precursor salt to the Ge precursor salt is 0.05:0.05-0.09; Step 2: freeze-drying the product of step 1; Step 3: subjecting the product obtained in step 2 to high-temperature heat treatment at a temperature of 800-1000° C. in a reducing atmosphere to obtain a ruthenium-germanium heterogeneous intermetallic compound.

2. The preparation method according to claim 1, characterized in that The Ge precursor salt in step 1 is (NH4)2GeF6; the Ru precursor salt is Ru(NO)(NO3)3.

3. The preparation method according to claim 1, characterized in that The carrier material described in step 1 is a surface-modified carrier material, which is at least one of graphene oxide, carbon nanotubes, and Ketjen black.

4. The preparation method according to claim 1, characterized in that The water-soluble polymer in the water-soluble polymer solution in step 1 is at least one of polyvinyl alcohol, polyacrylic acid or polyacrylamide; the concentration of the water-soluble polymer solution is 15-25 mg / mL.

5. The preparation method according to claim 1, characterized in that The millimole ratio of the Ru precursor salt to the Ge precursor salt is 0.05:0.075-0.

08.

6. The preparation method according to claim 5, characterized in that The carrier material is carbon nanotubes, and the water-soluble polymer in the water-soluble polymer solution is polyacrylamide.

7. The preparation method according to claim 1, characterized in that The reducing atmosphere described in step 3 is an argon-hydrogen mixed atmosphere, and the volume ratio of argon to hydrogen is 85-92:8-15; the freeze-drying temperature described in step 2 is -10°C to -45°C, and the drying time is 20-40h; the heating rate of the high-temperature heat treatment described in step 3 is 2-10°C / min, and the holding time is 5-20h.

8. A ruthenium-germanium heterogeneous intermetallic compound, characterized in that: The method is as described in any one of claims 1 to 7.

9. Use of the ruthenium-germanium heterogeneous intermetallic compound as claimed in claim 8 in preparing a catalyst.

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