Tungsten oxide-loaded ruthenium-tungsten alloy catalyst and preparation and application thereof in hydroxide reaction

Abstract

The invention relates to the field of food preservation, and discloses a tungsten oxide loaded ruthenium-tungsten alloy catalyst and preparation and application thereof in a hydroxidation reaction, and the tungsten oxide loaded ruthenium-tungsten alloy catalyst is prepared by the following steps: (1) dissolving a tungsten source in a solvent, stirring, carrying out ultrasonic treatment, then putting into a polytetrafluoroethylene reaction kettle, then putting into a drying oven, and carrying out a hydrothermal reaction; after the reaction is completed, cooling to room temperature, and washing, centrifuging and drying the obtained substance to obtain a precursor; (2) carrying out metal ruthenium loading on the prepared precursor by adopting a ruthenium source, and heating and evaporating to dryness to obtain a ruthenium-loaded precursor; and (3) the prepared ruthenium-loaded precursor is subjected to heat treatment in the reducing gas atmosphere, and the tungsten oxide-loaded ruthenium-tungsten alloy catalyst is obtained.The heterogeneous interface of the tungsten oxide-loaded ruthenium-tungsten alloy catalyst has wide application prospects, shows high catalytic activity, stability and conductivity in a hydrogen oxidation reaction, and can be used for preparing the tungsten oxide-loaded ruthenium-tungsten alloy catalyst. The catalyst is especially suitable for a hydroxide reaction in an alkaline medium.

Description

Technical Field

[0001] The present invention relates to the field of electrocatalysis technology, and more specifically to a tungsten oxide-supported ruthenium-tungsten alloy catalyst, and its preparation and application in hydrogen oxidation reaction. Background Art

[0002] With the advancement of human science and technology and the continuous development of industrialization, various factories closely related to human life inevitably emit a large amount of exhaust gas, which has led to a sharp increase in the proportion of greenhouse gases in the atmosphere and produced a serious greenhouse effect. In order to control carbon emissions, China has proposed goals such as "carbon peak" and "carbon neutrality", and promised to offset and neutralize carbon dioxide emissions through energy conservation and emission reduction, afforestation, industrial adjustment, etc.

[0003] Therefore, developing new energy and gradually replacing fossil energy is of great significance to achieving the "dual carbon" goal. Although the common new energy sources such as wind energy, solar energy and tidal energy are environmentally friendly, their energy use is uncontrollable and has poor stability. In comparison, hydrogen energy has extremely high energy density and is environmentally friendly, so hydrogen energy has become the best choice to help achieve carbon neutrality. Based on the hydrogen oxidation reaction (HOR) and the hydrogen evolution reaction (HER), hydrogen energy realizes the conversion of energy storage and output through electrolyzers and fuel cells, and there is no greenhouse gas emission. Among them, the energy conversion process of hydrogen fuel cells has higher working efficiency than that of internal combustion engines.

[0004] At present, OH-exchange membranes and non-precious metal ORR electrocatalysts with excellent performance have been developed. However, it is worth noting that the anodic HOR reaction kinetics under alkaline conditions is 1-2 orders of magnitude lower than that under acidic conditions, which means that it is urgent to design low-cost, high-performance alkaline HOR electrocatalysts. To this end, we proposed a tungsten oxide-supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reactions. Summary of the invention

[0005] The purpose of the present invention is to provide a tungsten oxide-supported ruthenium-tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction in view of the deficiencies in the prior art, which has relatively excellent catalytic activity, stability and conductivity.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: comprising the following steps:

[0007] (1) dissolving a tungsten source in a solvent, stirring, ultrasonicating, and then placing it in a polytetrafluoroethylene reactor, and then placing it in an oven for hydrothermal reaction; after the reaction is completed, cooling to room temperature, washing, centrifuging, and drying the obtained substance to obtain a precursor;

[0008] (2) using a ruthenium source to load the above-prepared precursor with metal ruthenium, heating and evaporating to dryness, to obtain a ruthenium-loaded precursor;

[0009] (3) The ruthenium-loaded precursor prepared above is heat-treated in a reducing gas atmosphere to obtain a tungsten oxide-loaded ruthenium-tungsten alloy catalyst.

[0010] Furthermore, the tungsten source is tungsten chloride.

[0011] Furthermore, the solvent is ethanol.

[0012] Furthermore, the stirring and ultrasonic treatment lasts for 30 minutes.

[0013] Furthermore, the hydrothermal reaction temperature is 160-200° C., and the hydrothermal reaction time can be 16-24 hours.

[0014] Furthermore, the ruthenium source is ruthenium trichloride.

[0015] Preferably, the metal ruthenium is loaded by an impregnation method.

[0016] Preferably, the loading amount of ruthenium is 4-8%.

[0017] Furthermore, the nitrogen content in the reducing atmosphere is about 60%.

[0018] Preferably, the calcination temperature of the reduction heat treatment is 400-550°C.

[0019] Preferably, the calcination time is 1-2h.

[0020] Furthermore, the preparation obtains a tungsten oxide-supported ruthenium-tungsten alloy catalyst.

[0021] Furthermore, the tungsten oxide-loaded ruthenium-tungsten alloy catalyst is used in electrocatalytic hydrogen oxidation reactions.

[0022] Furthermore, the electrocatalytic hydrogen oxidation reaction is a hydrogen oxidation reaction in an alkaline medium using 0.1 M KOH as an electrolyte.

[0023] According to the above scheme,

[0024] Compared with the prior art, the beneficial effects are as follows:

[0025] The heterogeneous interface of the present invention has a relatively broad application prospect. It exhibits high catalytic activity, stability and conductivity in hydrogen oxidation reactions, is particularly suitable for hydrogen oxidation reactions in alkaline media, and can provide practical guidance for the development of efficient non-platinum-based electrochemical catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the ray diffraction diagram of the present invention;

[0027] Figure 2 It is a schematic diagram of a scanning electron microscope image of the present invention;

[0028] Figure 3 Schematic diagram of the HOR polarization curve of the present invention at different rotation speeds in a H2-saturated 0.1M KOH electrolyte;

[0029] Figure 4 Schematic diagram of Koutecky-Lev i ch obtained under 50 mV overpotential of the present invention;

[0030] Figure 5 This is a schematic diagram of HOR Tafe l of the present invention;

[0031] Figure 6 Schematic diagram of the HOR polarization curve of the present invention in a H2-saturated 0.1M KOH electrolyte at a rotation speed of 1600 rpm;

[0032] Figure 7 It is a schematic diagram of the comparison of the HOR catalytic activity of the present invention before and after 1000 CV cycles at an overpotential of 50 mV and a rotation speed of 1600 rpm;

[0033] Figure 8 This is a current-time schematic diagram of the present invention at 50 mV overpotential. DETAILED DESCRIPTION

[0034] The invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are merely illustrative and are not intended to limit the scope of protection of the present invention.

[0035] refer to Figure 1-8 As shown, the present invention provides a method for preparing a tungsten oxide-supported ruthenium-tungsten alloy catalyst, comprising the following steps:

[0036] (1) dissolving a tungsten source in a solvent, stirring, ultrasonicating, and then placing it in a polytetrafluoroethylene reactor, and then placing it in an oven for hydrothermal reaction; after the reaction is completed, cooling to room temperature, washing, centrifuging, and drying the obtained substance to obtain a precursor;

[0037] (2) using a ruthenium source to load the above-prepared precursor with metal ruthenium, heating and evaporating to dryness, to obtain a ruthenium-loaded precursor;

[0038] (3) The ruthenium-loaded precursor prepared above is heat-treated in a reducing gas atmosphere to obtain a tungsten oxide-loaded ruthenium-tungsten alloy catalyst.

[0039] Among them; the tungsten source is tungsten chloride, the solvent is ethanol, the stirring and ultrasonic time is 30 minutes, the hydrothermal reaction temperature is 160-200°C, the hydrothermal reaction time can be 16-24 hours, the ruthenium source is ruthenium trichloride, the metal ruthenium is loaded by impregnation method, the ruthenium loading amount is 4-8%, the nitrogen content in the reducing atmosphere is about 60%, the calcination temperature of the reduction heat treatment is 400-550°C, and the calcination time is 1-2 hours.

[0040] Wherein: in step (1), tungsten chloride and ethanol are hydrothermally reacted to generate a tungsten oxide precursor; in step (2), a ruthenium source is added based on the precursor to synthesize a ruthenium-loaded tungsten oxide precursor; and in step (3), a tungsten oxide-loaded ruthenium tungsten alloy catalyst is synthesized.

[0041] Among them; the present invention also provides a tungsten oxide-loaded ruthenium tungsten alloy catalyst prepared according to the aforementioned preparation method, and the present invention further provides the use of the aforementioned tungsten oxide-loaded ruthenium tungsten alloy catalyst in an electrocatalytic hydrogen oxidation reaction, and the electrocatalytic hydrogen oxidation reaction is a hydrogen oxidation reaction in an alkaline medium with 0.1M KOH as an electrolyte.

[0042] Example 1

[0043] Preparation of tungsten oxide supported ruthenium tungsten alloy catalyst:

[0044] (1) Dissolve 900 mg of tungsten chloride in 180 mL of ethanol, stir, and ultrasonicate for 30 min until the solution turns golden yellow. Then transfer the solution to a polytetrafluoroethylene reactor and place it in an oven for hydrothermal reaction. Set the reaction temperature to 180 ° C and the reaction time to 16 h. After cooling to room temperature, wash with deionized water and ethanol for more than 3 times. Place the washed sample in a vacuum oven for 12 h. Finally, obtain the precursor.

[0045] (2) 100 mg of the above-prepared precursor was placed in a beaker, stirred and ultrasonicated for 30 min, and then ruthenium trichloride was added to the solution. The beaker was then placed in a heating stirrer, stirred and heated, and evaporated to dryness before recovery.

[0046] (3) 60 mg of the ruthenium-loaded precursor prepared above was calcined at 500° C. for 2 h in a reducing atmosphere (nitrogen content of 60%) to obtain a tungsten oxide-loaded ruthenium tungsten alloy catalyst, denoted as Ru-W / WOx, wherein the ruthenium loading was 7%.

[0047] The Ru-W / WOx sample prepared in Example 1 was characterized by the following structure. Figure 1 .

[0048] Figure 1 All the diffraction peaks that appear in the correspond well to those of pure Ru-W and pure WOx; Figure 2 It shows that the Ru-W / WOx sample has a nanowire structure morphology.

[0049] Example 2

[0050] The application of the Ru-W / WOx sample prepared in Example 1 as a catalyst in electrocatalytic hydrogen oxidation:

[0051] The HOR electrocatalytic test was carried out on an electrochemical workstation using a standard three-electrode system, with 0.1 M KOH solution filled with hydrogen as the electrolyte, a rotating disk electrode (RDE) modified with Ru-W / WOx as the working electrode (4 mg of the Ru-W / WOx sample prepared in Example 1 was dispersed in 1000 μL ethanol containing 40 uL 5 wt% Nafion and ultrasonicated for 1 h to prepare the ink; then 7.5 μL of the ink was dropped onto the polished rotating disk electrode to obtain the working electrode), a platinum wire as the counter electrode, and an Ag / AgCl electrode as the reference electrode.

[0052] At the same time, a control example was set up in which commercial Pt / C was used as a catalyst to replace Ru-W / WOx to prepare a working electrode. The Pt content in the Pt / C was 20%, and the other conditions were the same as above.

[0053] like Figure 3 and Figure 4 As shown, there is a linear relationship between the kinetic current density j and ω1 / 2 of RDE at an overpotential of 50 mV. The fitting straight line is expressed by the Koutecky-Lev i ch equation with a slope of 4.63 cm2·mA-1·s-1 / 2, which is close to the theoretical value (4.87 cm2·mA-1·s-1 / 2 for two-electron HOR).

[0054] from Figure 5 and Figure 6 It can be seen that the HOR catalytic activity of Ru-W / WOx in alkaline medium is significantly better than that of Pt / C.

[0055] from Figure 7 It can be seen that Ru-W / WOx has extremely high stability in alkaline medium.

[0056] from Figure 8 It can be seen that the HOR catalytic activity of Ru-W / WOx in alkaline medium can remain stable within 60000s.

[0057] In summary, the Ru-W / WOx prepared in the present invention has better HOR catalytic activity than the commercial Pt / C catalyst in alkaline medium and has good stability.

[0058] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction, characterized in that: The following steps are involved: (1) dissolving a tungsten source in a solvent, stirring, ultrasonicating, and then placing it in a polytetrafluoroethylene reactor, and then placing it in an oven for hydrothermal reaction; after the reaction is completed, cooling to room temperature, washing, centrifuging, and drying the obtained substance to obtain a precursor; (2) using a ruthenium source to load the above-prepared precursor with metal ruthenium, heating and evaporating to dryness, to obtain a ruthenium-loaded precursor; (3) The ruthenium-loaded precursor prepared above is heat-treated in a reducing gas atmosphere to obtain a tungsten oxide-loaded ruthenium-tungsten alloy catalyst.

2. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction according to claim 1, characterized in that: The tungsten source is tungsten chloride.

3. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction according to claim 1, characterized in that: The solvent is ethanol.

4. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction according to claim 1, characterized in that: The stirring and ultrasonic treatment lasts for 30 min.

5. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and application in hydrogen oxidation reaction according to claim 1, characterized in that: The hydrothermal reaction temperature is 160-200° C., and the hydrothermal reaction time can be 16-24 hours.

6. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and use in hydrogen oxidation reaction according to claim 1, characterized in that: The ruthenium source is ruthenium trichloride, the metal ruthenium is loaded by an impregnation method, and the loading amount of ruthenium is 4-8%.

7. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and use in hydrogen oxidation reaction according to claim 1, characterized in that: The nitrogen content in the reducing atmosphere is about 60%, the calcination temperature of the reducing heat treatment is 400-550° C., and the calcination time is 1-2 hours.

8. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and use in hydrogen oxidation reaction according to claim 1, characterized in that: The tungsten oxide-supported ruthenium-tungsten alloy catalyst is prepared.

9. The tungsten oxide supported ruthenium tungsten alloy catalyst and its preparation and use in hydrogen oxidation reaction according to claim 8, characterized in that: The tungsten oxide-supported ruthenium-tungsten alloy catalyst is used in an electrocatalytic hydrogen oxidation reaction.

10. The tungsten oxide supported ruthenium tungsten alloy catalyst according to claim 9, and its preparation and use in hydrogen oxidation reaction, characterized in that: The electrocatalytic hydrogen oxidation reaction is a hydrogen oxidation reaction in an alkaline medium using 0.1 M KOH as an electrolyte.

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