Platinum-doped nickel-molybdenum-based self-supporting nano catalytic material and application thereof in electrolytic hydrogen production

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production, and relates to a simple liquid phase synthesis method of a platinum-doped nickel-molybdenum-based self-supporting nano catalytic material and an electro-catalytic hydrogen evolution (HER) application of the platinum-doped nickel-molybdenum-based self-supporting nano catalytic material. The material is prepared by taking commercial foamed nickel molybdenum as a substrate, soaking the substrate in a platinum-containing solution at a high temperature and then performing post-treatment. The obtained self-supporting catalyst not only shows excellent HER catalytic activity, but also has the advantages of simple preparation process (rapid reaction and no need of complex equipment) and low dosage of precious metal platinum, and has the potential of industrial large-scale preparation and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, in particular to a platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material prepared by a liquid-phase synthesis method, and application of the catalyst in hydrogen production by water electrolysis. BACKGROUND

[0002] Under the background of increasingly severe global warming challenges, it has become a top priority to find clean energy that can replace traditional fossil fuels. High-current-density water electrolysis technology, as a key means of industrial-level green hydrogen production, plays a core role in energy decarbonization and sustainable industrial applications. Although significant breakthroughs have been made in laboratory-scale water electrolysis catalyst design, the performance limitations of its sustained existence under industrial high-current-density conditions have not been addressed. The technical route of coupling electrocatalytic water splitting with supercapacitor systems has attracted considerable attention as an important direction for sustainable energy development due to its excellent potential in energy storage and conversion. To achieve truly sustainable electrochemical devices, the key lies in developing hydrogen evolution electrocatalysts with high efficiency, high stability, and high-current-density tolerance.

[0003] Upon reviewing the current development status of electrocatalysts used in large-scale commercial alkaline electrolyzers, we found that nickel foam (NF) has gained widespread attention due to its low cost, suitable catalytic activity, and stability in alkaline electrolytes. At the same time, specific nickel alloy foams (such as nickel-molybdenum foam) exhibit superior hydrogen evolution (HER) and oxygen evolution (OER) performance to pure nickel foam. Existing research has fully demonstrated that to achieve truly energy-efficient and large-scale clean hydrogen production capabilities at a commercial application level, performance must be improved through optimization of the microstructure, component regulation, phase design, and surface modification of electrocatalysts.

[0004] Platinum (Pt) is widely recognized and used as a key catalyst for the cathodic hydrogen evolution reaction (HER), and its core advantage lies in its ability to achieve nearly optimal hydrogen adsorption free energy (ΔGH≈0). This unique property is the fundamental reason for platinum's high efficiency in catalyzing HER. According to the Sabatier principle, the adsorption strength of an ideal catalyst for reaction intermediates (here, adsorbed hydrogen atoms H*) should be just right: too strong will cause the catalyst surface to be excessively covered with hydrogen atoms, "poisoning" and hindering subsequent reaction steps; too weak will not favor hydrogen atom adsorption and activation, also reducing reaction rate. Platinum is located near the top of the "volcano plot" describing the relationship between HER catalytic activity and hydrogen adsorption energy, with its hydrogen adsorption energy slightly below zero (usually around -0.09 eV), very close to the theoretical optimal value (0 eV). This allows the platinum surface to effectively adsorb and activate reactants (H*), and also facilitates the combination of adsorbed hydrogen atoms into hydrogen gas molecules (H2) and their smooth desorption with a lower energy barrier.

[0005] Therefore, the present application utilizes the platinum to regulate the electronic structure of surrounding atoms, and the excellent hydrogen adsorption energy of platinum, and the like, to prepare a high-efficiency hydrogen evolution reaction self-supporting catalyst by doping trace platinum into commercial metal foam nickel-molybdenum. SUMMARY

[0006] The present application solves the technical problems:

[0007] The present application utilizes a liquid phase synthesis method to prepare a platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material, which has excellent HER performance, solves the problems of low electrocatalytic activity and environmental unfriendliness in the prior art, and has a simple preparation process, reduces the loading amount of noble metal platinum, avoids complicated steps in the preparation of the catalyst, and reduces the preparation cost of the catalyst.

[0008] The technical scheme adopted by the present application:

[0009] First, a potassium chloroplatinate solution is configured as a reaction liquid, and then the commercial metal foam nickel-molybdenum is immersed in the reaction liquid, and after being taken out, the commercial metal foam nickel-molybdenum is cleaned with pure water to obtain a platinum-doped nickel-molybdenum-based catalyst material.

[0010] The specific content is as follows:

[0011] First, the present application provides a platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material, wherein the platinum-modified nickel / molybdenum hydroxide microparticle is closely grown on the surface of a commercial foam nickel-molybdenum substrate.

[0012] The catalyst is treated with a potassium chloroplatinate solution as a treatment liquid, and the corrosion effect of chloride ions is utilized to slightly corrode the surface of the commercial metal foam nickel-molybdenum, and at the same time, platinum elements are successfully doped into the commercial metal foam nickel-molybdenum to form a platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material.

[0013] The reaction liquid has the following characteristics: the mass concentration of potassium chloroplatinate is 1g / L.

[0014] Second, the present application provides the application of the aforementioned platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material in the electrolysis of water to produce hydrogen.

[0015] A standard three-electrode system is utilized, the platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material is used as a cathode, a mercury / mercuric oxide electrode is used as a reference electrode, and a platinum sheet is used as a counter electrode, and the HER test is performed thereon.

[0016] The platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material (Pt-NiMo) obtained by the present application has a rough surface after being corroded by chloride ions and modified by platinum, and this structure is beneficial to the exposure of electrochemical active sites.

[0017] For HER, it is 10mAcm -2 , 50mAcm -2 and 100mAcm-2 The overpotentials are 14.05 mV, 32.61 mV and 46.22 mV, respectively. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The LSV test results of the hydrogen evolution reaction (HER) of each experimental sample are shown in the following table:

[0019] Figure 2 The overpotentials of the hydrogen evolution reaction (HER) of each experimental sample are shown in the following table:

[0020] Figure 3 The stability test results of Pt-NiMo are shown in the following table: DETAILED DESCRIPTION

[0021] For the purpose of more clearly setting forth the technical solutions, advantages and merits of the embodiments of the present application, the technical solutions in the embodiments will be described in detail below. If no specific conditions are specified, the operations will be performed according to the normal conditions or the manufacturer's recommendations. If the manufacturers of the reagents or instruments are not specifically specified, they all refer to the conventional products that can be purchased in the market.

[0022] EMBODIMENT

[0023] The platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material is prepared by the following steps: a 1 g / L potassium chloroplatinate solution is configured as a reaction liquid. The reaction liquid is heated in a 90°C environment. A clean commercial metal foam nickel-molybdenum substrate is then placed in the above reaction liquid for 1 hour. After being taken out, the substrate is washed with deionized water and then dried by wiping the surface with filter paper. The final sample is obtained after air drying at room temperature (labeled as Pt-NiMo, where Pt represents potassium chloroplatinate treatment and NiMo represents the metal foam nickel-molybdenum substrate).

[0024] COMPARATIVE EXAMPLE 1

[0025] The platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material is prepared by the following steps: a 1 g / L potassium chloroplatinate solution is configured as a reaction liquid. The reaction liquid is heated in a 90°C environment. A clean commercial metal foam nickel-molybdenum substrate is then placed in the above reaction liquid for 1 hour. After being taken out, the substrate is washed with deionized water and then dried by wiping the surface with filter paper. The final sample is obtained after air drying at room temperature (labeled as Pt-NiMo, where Pt represents potassium chloroplatinate treatment and NiMo represents the metal foam nickel-molybdenum substrate).

[0026] COMPARATIVE EXAMPLE 2

[0027] The commercial metal foam nickel-molybdenum substrate is not treated.

[0028] The specific amounts of each reagent used in the examples and comparative examples, and the treatment time, are shown in Table 1.

[0029] Table 1: Parameter ratio table and treatment time

[0030]

[0031] Test Example

[0032] 1. CV, LSV, EIS and i-t tests

[0033] The HER performance of each supported catalytic material in the examples and comparative examples was tested. Using a standard three-electrode system, a commercial metal foam nickel molybdenum substrate was used as the cathode, mercury / mercury oxide (Hg / HgO) as the reference electrode, and a platinum sheet as the anode. The voltage window was set to -0.5 to -1.5 V (vs. Hg / HgO) using a Wuhan Kostar Corrtest Studio 6 electrochemical workstation.

[0034] The material stability was evaluated using a constant potential technique (with -100 mA as the evaluation standard).

[0035] The HER test results are shown in Table 2 and Figures 1-3 .

[0036] Table 2: Hydrogen evolution reaction (HER) overpotential test results

[0037]

[0038] Figure 1 The LSV polarization curves of the hydrogen evolution reaction (HER) of each supported catalytic material are shown in the figure. It can be seen that the HER performance of the material after the commercial metal foam nickel molybdenum is treated with potassium chloroplatinate is significantly improved. Pt-NiMo shows the best HER performance, followed by Pt-Ni and NiMo, indicating that the combination of molybdenum and platinum improves the HER performance of the material, and the improvement of platinum is more significant.

[0039] Figure 2 The HER overpotential graph of each supported catalytic material is shown in the figure. Figure 2 It can be seen that the overpotential of Pt-NiMo at a current density of 10 mA cm -2 , 50 mA cm -2 and 100 mA cm -2 is 14.05 mV, 32.61 mV and 46.22 mV (denoted as 14.05 mV@10 mA cm -2 , 32.61 mV@50 mA cm -2 and 46.22 mV@100 mA cm -2 , respectively), which is significantly improved compared to the performance of the commercial foam nickel molybdenum.

[0040] Figure 3The Pt-NiMo HER stability test chart. At least 100 hours of stable operation at -100 mA meets the industrial application.

[0041] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material, characterized in that: Microspheres are uniformly grown on the surface of commercial nickel-molybdenum metal foam.

2. A platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material obtained by liquid phase synthesis, characterized in that: The reaction liquid is a platinum-containing solution, in which the platinum source is potassium chloroplatinate (K2PtCl6). Clean commercial metal foam nickel iron is placed in the above platinum-containing solution and allowed to stand, then taken out and post-processed to obtain platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material. Further: (1) The commercial nickel-molybdenum metal foam has an area of ​​1 cm*1.5 cm; (2) The mass concentration of potassium chloroplatinate is 1 g / L; (3) The substrate is placed in a platinum-containing solution and reacted at 90°C; (4) The substrate is treated in the platinum-containing solution for 1 h.

3. The platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material according to claim 1, characterized in that: The surface is evenly covered with nanosheet structures.

4. Use of the platinum-doped nickel-molybdenum-based self-supporting nanocatalytic material according to claims 1-3 as a cathode material in hydrogen production by electrolysis of water.

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