La and s co-doped foam nickel-based electrolytic water catalyst, and preparation method and application thereof
By doping lanthanum and sulfur components onto a nickel foam substrate, a high-performance water electrolysis catalyst was prepared, solving the problem of scarce precious metal catalyst resources. This achieved low-cost, high-activity, and stable hydrogen production through water electrolysis, thus promoting the commercialization of water electrolysis hydrogen production technology.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANTONG UNIV
- Filing Date
- 2026-03-04
- Publication Date
- 2026-06-02
AI Technical Summary
Existing commercial water electrolysis catalysts rely on precious metals, which are scarce and expensive, making it difficult to scale up the application of water electrolysis hydrogen production technology. Non-precious metal catalysts have insufficient activity and poor stability.
A high-performance catalyst was prepared by uniformly loading lanthanum and sulfur components onto a nickel foam substrate via a hydrothermal method. The catalyst mainly consists of Ni3S2 and La doped phases and has abundant catalytic active sites and good conductivity.
The prepared catalyst exhibits excellent kinetic performance in HER and OER reactions, with a low Tafel slope and high current density. It is also low in cost and simple to process, making it suitable for large-scale production and providing support for the commercial application of water electrolysis hydrogen production technology.
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Figure CN122128747A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of water electrolysis catalyst technology, and in particular to a lanthanum-sulfur co-doped nickel-based foamed water electrolysis catalyst, its preparation method, and its application. Background Technology
[0003] In the hydrogen production pathway, "green hydrogen" has become the core development direction of the hydrogen energy industry because it relies entirely on renewable energy sources (such as photovoltaic and wind power) for power supply and has no carbon emissions throughout the process. Electrolysis of water to produce hydrogen is the main production technology of green hydrogen. This process decomposes water molecules into hydrogen and oxygen through electrochemical means, and has outstanding advantages such as high product purity, strong environmental compatibility, and flexible matching with renewable energy.
[0004] In the electrolysis of water to produce hydrogen, the catalyst is a key material for reducing the activation energy, improving electrolysis efficiency, and reducing energy consumption. Currently, commercially available water electrolysis catalysts mainly rely on precious metals (such as Pt-based catalysts for HER and Ir / Ru-based catalysts for OER), but their scarcity and high cost severely restrict the large-scale commercial application of water electrolysis hydrogen production technology. Therefore, developing low-cost, highly active, and long-term stable non-precious metal or low-precious metal-doped catalysts has become a research hotspot in this field.
[0005] Nickel foam (NF) is often used as a substrate material for water electrolysis catalysts due to its high specific surface area, good electrical conductivity, three-dimensional porous structure, and excellent mechanical stability. Lanthanum (La), as a rare earth element, can adjust the electronic state density of the catalyst and optimize the adsorption energy of reaction intermediates due to its unique electronic structure and chemical properties; the introduction of sulfur (S) can regulate the crystal structure and surface electronic properties of the catalyst and increase the number of catalytic active sites.
[0006] Based on this, the present invention prepares a high-performance water electrolysis catalyst by doping lanthanum-sulfur components onto a nickel foam substrate using a simple hydrothermal method, thereby solving the problems of insufficient activity and poor stability of existing non-precious metal catalysts. Summary of the Invention
[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a lanthanum-sulfur co-doped foam nickel-based electrolytic water catalyst, its preparation method, and its application. This method is simple to prepare, low in cost, and environmentally friendly. The prepared catalyst has high catalytic activity, good stability, and excellent conductivity, and can simultaneously and efficiently catalyze the HER and OER reactions, providing support for the large-scale application of water electrolysis for hydrogen production.
[0008] To achieve the above objectives, the present invention adopts the following technical solution: a method for preparing a lanthanum-sulfur co-doped nickel-based foamed water electrolysis catalyst, comprising the following steps:
[0009] Step 1, Nickel foam pretreatment: Select nickel foam and ultrasonically clean it in sequence with ethanol, deionized water, acetone, hydrochloric acid solution and deionized water to remove the surface oxide layer and impurities. After ultrasonic treatment, vacuum dry it for later use.
[0010] Step 2, Preparation of precursor solution: Weigh out the lanthanum-containing compound and the sulfur-containing compound, disperse them in deionized water, and stir magnetically until completely dissolved to obtain a homogeneous precursor solution;
[0011] Step 3, hydrothermal reaction: Place the pretreated nickel foam from Step 1 into a polytetrafluoroethylene (PTFE) liner, pour in the precursor solution prepared in Step 2, seal the PTFE liner in the reactor, carry out the hydrothermal reaction, and allow it to cool naturally after the reaction is complete.
[0012] Step 4, Catalyst post-treatment: The nickel foam after the reaction is removed, and it is washed alternately with deionized water and ethanol. After vacuum drying, the supported LaS@NF water electrolysis catalyst is obtained. The remaining solution after the reaction is collected, the precipitate is separated by centrifugation, and the powdered LaS@NF water electrolysis catalyst is obtained by vacuum drying.
[0013] Preferably, in step 1, the size of the nickel foam is 3×3 cm. 2 The concentration of hydrochloric acid solution was 3 M; the ultrasonic power was 100-150 W; the ultrasonic cleaning conditions were: ethanol cleaning for 20-30 min, deionized water cleaning for 10-15 min, 10-15 ml acetone cleaning for 20-30 min, 3 M hydrochloric acid solution cleaning for 10-15 min, and finally deionized water cleaning 3 times, 15-30 min each time; the vacuum drying temperature was 45-60 ℃, and the drying time was 8-10 h.
[0014] Preferably, in step 2, the lanthanum-containing compound is lanthanum nitrate hexahydrate (La(NO3)3 6H2O), and the amount used is 0.2~0.3 g; the sulfur-containing compound is thiourea (CS(NH2)2), and the amount used is 0.1~0.5 g; the amount of deionized water is 35~40 g; the magnetic stirring temperature is room temperature, and the stirring time is 10~15 min.
[0015] Preferably, in step 2, the lanthanum-containing compound can be replaced by one of lanthanum chloride, lanthanum sulfate, lanthanum acetate, and lanthanum acetylacetonate; the sulfur-containing compound can be replaced by one of sodium sulfide, sodium thiosulfate, ammonium sulfate, and ammonium sulfide.
[0016] Preferably, in step 3, the hydrothermal reaction temperature is 170~200 ℃ and the reaction time is 2~6 h.
[0017] Preferably, in step 4, the cleaning conditions are as follows: first, wash with deionized water 2-4 times, then wash with ethanol 1-2 times, with each cleaning time being 5-10 min; the vacuum drying temperature is selected as 45-60 ℃, and the drying time is 12-15 h.
[0018] Preferably, in step 4, the centrifugal rotation speed is 8000~10000 r / min. -1 The centrifugation time is 20-30 min; the temperature for vacuum drying of the precipitate is 45-60 ℃, and the drying time is 12-15 h. The precipitate is washed with deionized water 2-3 times before drying.
[0019] The present invention also provides a lanthanum-sulfur co-doped nickel foam-based electrolytic water catalyst prepared by the above-described method.
[0020] This invention further provides an application of the above-mentioned lanthanum-sulfur co-doped foam nickel-based water electrolysis catalyst in the water electrolysis hydrogen production reaction.
[0021] By adopting the above technical solution, the lanthanum-sulfur co-doped foam nickel-based electrolytic water catalyst (LaS@NF) prepared by the present invention achieves uniform loading of lanthanum-sulfur components on a foam nickel substrate through a simple hydrothermal synthesis method. The catalyst mainly consists of Ni3S2, Ni and La doped phases, and has abundant catalytic active sites and good conductivity.
[0022] All the materials used to prepare the precursors mentioned above are commercially available products.
[0023] Compared with the prior art, the present invention has the following beneficial effects:
[0024] 1. This invention enables the targeted preparation of three different catalysts by precisely controlling the amount of thiourea, among which LaS... 0.1 @NF catalysts exhibit the best performance.
[0025] 2. Electrochemical tests of this invention show that LaS 0.1 The HER Tafel slope of the @NF catalyst is as low as 88.09 mVdec. -1 The OER Tafel slope is as low as 64.22 mV dec -1 It exhibits excellent reaction kinetics and a current density that can reach 4500 mAcm. -2 .
[0026] 3. The catalyst prepared by this invention is made from inexpensive raw materials, the process is simple, economical and environmentally friendly, and it can be mass-produced. It also has a stable structure and good toughness, which provides strong support for the commercial application of water electrolysis hydrogen production technology. Attached Figure Description
[0027] Figure 1The LaS prepared in Example 1 of this invention 0.1 Scanning electron microscope and elemental distribution map of @NF catalyst;
[0028] Figure 2 The above are HER linear sweep voltammetry curves of the LaS@NF catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention.
[0029] Figure 3 The OER linear sweep voltammetry curves of the LaS@NF catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention are shown.
[0030] Figure 4 The HER Tafel curves of the LaS@NF catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention are shown.
[0031] Figure 5 The OER Tafel curves are shown for the LaS@NF catalysts prepared in Example 1 and Comparative Examples 1-2 of this invention. Detailed Implementation
[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the scope of protection of the present invention. The embodiments described in this invention are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0033] Example 1:
[0034] LaS 0.1 Preparation of @NF catalysts:
[0035] (1) Take 3×3 cm 2 Nickel foam was sequentially immersed in ethanol, deionized water, 15 ml acetone, 3 M hydrochloric acid solution, and deionized water, and ultrasonically cleaned at 100 W each time: ethanol for 30 min, deionized water for 15 min, acetone for 30 min, hydrochloric acid solution for 15 min, and finally rinsed three times with deionized water (15 min each time) to remove the surface oxide layer and impurities. After cleaning, it was placed in a vacuum drying oven at 50 ℃ for 10 h for later use.
[0036] (2) Weigh 0.2 g of lanthanum nitrate hexahydrate (La(NO3)3・6H2O) and 0.1 g of thiourea (CS(NH2)2), add them to 40 g of deionized water, and stir magnetically for 15 min at room temperature until completely dissolved to obtain a homogeneous precursor solution;
[0037] (3) Place the pretreated nickel foam from step (1) into a 50 mL polytetrafluoroethylene liner, pour in the precursor solution prepared in step (2), and ensure that the nickel foam is completely submerged; seal the polytetrafluoroethylene liner in the reactor and place it in an oven at 180 °C for 4 h.
[0038] (4) After the reaction is complete, allow the material to cool naturally to room temperature. Remove the nickel foam and clean it twice with deionized water using ultrasound, then clean it once with ethanol using ultrasound, each time for 5 min. Place the nickel foam in a vacuum drying oven at 50 ℃ and dry it for 14 h to obtain LaS. 0.1 @NF catalyst;
[0039] (5) Collect the remaining solution after the reaction in step (4), put it into a centrifuge, and centrifuge at 8000 r / min. -1 Centrifuge at 25 min and collect the precipitate; wash the precipitate twice with deionized water and dry it in a vacuum drying oven at 50 ℃ for 14 h to obtain powdered LaS. 0.1 @NF catalyst.
[0040] Comparative Example 1:
[0041] LaS 0.3 Preparation of @NF catalysts:
[0042] (1) The pretreatment steps for nickel foam are the same as those in step (1) of Example 1;
[0043] (2) Weigh 0.2 g of lanthanum nitrate hexahydrate (La(NO3)3 6H2O) and 0.3 g of thiourea (CS(NH2)2), add them to 40 g of deionized water, and stir magnetically for 15 min at room temperature until completely dissolved to obtain a homogeneous precursor solution;
[0044] (3) The hydrothermal reaction steps are the same as those in step (3) of Example 1;
[0045] (4) The catalyst post-treatment steps are the same as step (4) in Example 1, to obtain LaS 0.3 @NF catalyst;
[0046] (5) The preparation steps of the powdered catalyst are the same as those in step (5) of Example 1, and powdered LaS is obtained. 0.3 @NF catalyst.
[0047] Comparative Example 2:
[0048] LaS 0.5 Preparation of @NF catalysts:
[0049] (1) The pretreatment steps for nickel foam are the same as those in step (1) of Example 1;
[0050] (2) Weigh 0.2 g of lanthanum nitrate hexahydrate (La(NO3)3・6H2O) and 0.5 g of thiourea (CS(NH2)2), add them to 40 g of deionized water, and stir magnetically for 15 min at room temperature until completely dissolved to obtain a homogeneous precursor solution;
[0051] (3) The hydrothermal reaction steps are the same as those in step (3) of Example 1;
[0052] (4) The catalyst post-treatment steps are the same as step (4) in Example 1, to obtain LaS 0.5 @NF catalyst;
[0053] (5) The preparation steps of the powdered catalyst are the same as those in step (5) of Example 1, and powdered LaS is obtained. 0.5 @NF catalyst.
[0054] Electrochemical testing: A 1.0 mol / L KOH solution was used as the electrolyte, and a three-electrode system was employed. The LaS@NF catalyst electrodes prepared in Example 1 and Comparative Examples 1-2 were used as working electrodes, mercuric oxide electrodes as reference electrodes, and graphite electrodes as counter electrodes. The linear sweep voltammetry and Tafel curves of the catalysts were measured using a Chenhua electrochemical workstation (model CHI 604 E).
[0055] Appendix Figure 1 LaS can be clearly observed in 0.1 The @NF catalyst exhibits a porous microstructure, with Ni, La, and S elements uniformly distributed on the nickel foam substrate without significant agglomeration, confirming successful co-doping of the lanthanum-sulfur component; (See attached image) Figure 2 With appendix Figure 3 The results show that LaS 0.1 @NF exhibits higher current densities than LaS at the same potential in both the HER and OER reactions. 0.3 @NF、LaS 0.5 @NF exhibits the best activity for hydrogen evolution and oxygen evolution; (see attached image) Figure 4 LaS 0.1 @NF's HER Tafel slope is 88.09 mV dec -1 Significantly lower than LaS 0.3 @NF's 111.06 mVdec -1 and LaS 0.5 @NF's 91.4 mV dec -1 The HER reaction kinetics are superior; (attached) Figure 5 LaS 0.1 @NF's OER Tafel slope is 64.22 mV dec -1 Superior to LaS 0.3 @NF's 73.98 mV dec-1 and LaS 0.5 @NF's 90.33 mV dec -1 OER has a faster reaction rate.
[0056] The above test results confirm that when the amount of thiourea is adjusted to 0.1 g, the prepared LaS 0.1 @NF catalysts exhibited optimal overall performance in both HER and OER reactions, which is due to LaS 0.1 The structure of the @NF catalyst provides more active sites, and the synergistic effect of the lanthanum-sulfur components is more significant, optimizing the adsorption and desorption process of reaction intermediates.
[0057] In summary, the lanthanum-sulfur-doped nickel-foamed water electrolysis catalyst (LaS@NF) provided by this invention achieves optimized catalytic performance by simply adjusting the amount of thiourea (0.1 g, 0.3 g, 0.5 g), wherein LaS... 0.1 @NF exhibits the best overall performance, and is low in cost and easy to prepare, providing strong support for the commercial application of water electrolysis hydrogen production technology.
[0058] The descriptions and practices disclosed in this invention are readily apparent and understandable to those skilled in the art, and various modifications and refinements can be made without departing from the principles of this invention. Therefore, any modifications or improvements made without departing from the spirit of this invention should also be considered within the scope of protection of this invention.
Claims
1. A method for preparing a lanthanum-sulfur co-doped nickel-based foamed water electrolysis catalyst, characterized in that, Includes the following steps: Step 1, Nickel foam pretreatment: Select nickel foam and ultrasonically clean it in sequence with ethanol, deionized water, acetone, hydrochloric acid solution and deionized water to remove the surface oxide layer and impurities. After ultrasonic treatment, vacuum dry it for later use. Step 2, Preparation of precursor solution: Weigh out the lanthanum-containing compound and the sulfur-containing compound, disperse them in deionized water, and stir magnetically until completely dissolved to obtain a homogeneous precursor solution; Step 3, hydrothermal reaction: Place the pretreated nickel foam from Step 1 into a polytetrafluoroethylene (PTFE) liner, pour in the precursor solution prepared in Step 2, seal the PTFE liner in the reactor, carry out the hydrothermal reaction, and allow it to cool naturally after the reaction is complete. Step 4, Catalyst post-treatment: The nickel foam after the reaction is removed, and it is washed alternately with deionized water and ethanol. After vacuum drying, the supported LaS@NF water electrolysis catalyst is obtained. The remaining solution after the reaction is collected, the precipitate is separated by centrifugation, and the powdered LaS@NF water electrolysis catalyst is obtained by vacuum drying.
2. The method for preparing a lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 1, characterized in that, In step 1, the size of the nickel foam is 3×3 cm. 2 The concentration of hydrochloric acid solution was 3 M; the ultrasonic power was 100~150W; the ultrasonic cleaning conditions were: ethanol cleaning for 20~30 min, deionized water cleaning for 10~15 min, 10~15 ml acetone cleaning for 20~30 min, 3 M hydrochloric acid solution cleaning for 10~15 min, and finally deionized water cleaning 3 times, 15~30 min each time; the vacuum drying temperature was 45~60 ℃, and the drying time was 8~10 h.
3. The method for preparing a lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 1, characterized in that, In step 2, the lanthanum-containing compound is lanthanum nitrate hexahydrate La(NO3)3 6H2O, and the amount used is 0.2~0.3 g; the sulfur-containing compound is thiourea CS(NH2)2, and the amount used is 0.1~0.5 g; the amount of deionized water is 35~40 g; the magnetic stirring temperature is room temperature, and the stirring time is 10~15 min.
4. The method for preparing a lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 1, characterized in that, In step 2, the lanthanum-containing compound can be replaced by one of lanthanum chloride, lanthanum sulfate, lanthanum acetate, and lanthanum acetylacetonate; the sulfur-containing compound can be replaced by one of sodium sulfide, sodium thiosulfate, ammonium sulfate, and ammonium sulfide.
5. The method for preparing a lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 1, characterized in that, In step 3, the hydrothermal reaction temperature is 170~200 ℃, and the reaction time is 2~6 h.
6. The method for preparing a lanthanum-sulfur co-doped nickel-based foamed water electrolysis catalyst according to claim 1, characterized in that, In step 4, the cleaning conditions are as follows: first, wash with deionized water 2-4 times, then wash with ethanol 1-2 times, with each cleaning time being 5-10 min; the vacuum drying temperature is selected as 45-60 ℃, and the drying time is 12-15 h.
7. The preparation method of the lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 1, characterized in that, In step 4, the centrifugal separation speed is 8000~10000 r / min. -1 The centrifugation time is 20-30 min; the temperature for vacuum drying of the precipitate is 45-60 ℃, the drying time is 12-15 h, and the precipitate is washed with deionized water 2-3 times before drying.
8. The lanthanum-sulfur co-doped nickel foam-based water electrolysis catalyst obtained by the preparation method according to any one of claims 1-7.
9. The application of the lanthanum-sulfur co-doped nickel-based electrolytic water catalyst according to claim 8 in the electrolytic water hydrogen production reaction.