Synthetic method for improving catalyst loading capacity and electrochemical performance in hydrothermal reaction process

Abstract

The invention relates to the technical field of synthesis of electrolyzed water catalysts, in particular to a synthesis method for improving the loading capacity and electrochemical performance of a catalyst in a hydrothermal reaction process. The synthesis method comprises the following steps: carrying out ultrasonic treatment on a titanium felt to obtain a pretreated titanium felt; performing acid etching treatment on the pre-treated titanium felt through an oxalic acid solution to obtain an acid-treated titanium felt; and mixing the acid-treated titanium felt, the mixed reaction solution and the reaction solvent, and performing hydrothermal reaction to obtain the composite catalyst. According to the preparation method, firstly, the titanium felt is subjected to acid etching treatment to obtain the acid-treated titanium felt, then the ruthenium source and the composite surfactant are mixed and dispersed to construct the mixed reaction solution, finally, the acid-treated titanium felt and the mixed reaction solution are mixed and subjected to a hydrothermal reaction to obtain the composite catalyst, and the loading capacity and the electrochemical performance of Ru are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic water catalyst synthesis, and in particular to a synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction. Background Art

[0002] The importance of catalysts in chemical reactions is self-evident, especially in the fields of industrial chemistry, environmental governance, and energy conversion. Catalysts can not only increase reaction rates, but also selectively promote the occurrence of specific reactions. With the advancement of science and technology, the research and development of catalysts has become an important direction in chemical research. Among them, the preparation of catalysts by hydrothermal reaction has gradually attracted attention due to its unique advantages. Hydrothermal reaction refers to a chemical reaction using water as a reaction medium under high temperature and high pressure conditions. This reaction is usually carried out in a closed reactor, with the temperature generally between 100℃ and 300℃ and the pressure reaching tens of atmospheres. The characteristics of hydrothermal reaction are mainly reflected in the following aspects: (1) High temperature and high pressure environment: The physical and chemical properties of water change significantly under high temperature and high pressure. For example, the solubility and reaction activity of water are enhanced, allowing some insoluble substances to fully react in water; (2) Uniform dispersion of reactants: Hydrothermal reaction can achieve good dispersion of reactants, promote the uniformity of reaction, and thus improve the synthesis efficiency of catalysts; (3) Green chemistry: Water as a reaction medium is an environmentally friendly solvent. Compared with organic solvents, the use of hydrothermal reaction can reduce environmental pollution and safety hazards.

[0003] Hydrothermal reaction plays an important role in the preparation of catalysts, which is mainly reflected in the following aspects: (1) Control of particle size and morphology: Hydrothermal reaction can accurately control the particle size and morphology of the catalyst by adjusting the reaction conditions (such as temperature, pressure, reaction time, etc.). The particle size and morphology have an important influence on the activity and selectivity of the catalyst; (2) Improvement of catalyst stability: During the hydrothermal synthesis process, the crystal structure of the catalyst is often more complete, which can improve the thermal stability and chemical stability of the catalyst in the reaction; (3) Synthetic diversity: By adjusting the reaction conditions and reactant composition, various types of catalysts can be synthesized, such as metal catalysts, metal oxide catalysts and their composite materials. This diversity enables researchers to design the most suitable catalyst according to different reaction requirements; (4) Simple post-processing: After hydrothermal synthesis, the separation and purification of the catalyst is relatively simple. Usually, high-purity catalysts can be obtained by filtering and drying.

[0004] Although hydrothermal reactions have many advantages in catalyst synthesis, in actual operation, hydrothermal reactions often have some problems that lead to low catalyst loading and unsatisfactory performance: (1) Reaction temperature: Too high or too low reaction temperature may have a negative impact on the catalyst loading and performance. High temperature may cause sintering of active components, reducing specific surface area and activity, while low temperature may lead to insufficient reaction and insufficient loading; (2) Reaction time: Too short reaction time may lead to precipitation and insufficient loading of active components, while too long reaction time may cause aggregation or sintering of active components, thereby reducing the effective loading and performance of the catalyst; (3) Reactant concentration: Too high reactant concentration may lead to the rapid formation of precipitates, resulting in particle aggregation and uneven loading, while too low reactant concentration may lead to insufficient loading, affecting the performance of the catalyst.

[0005] Therefore, how to increase the loading amount of the catalyst is a technical problem that needs to be solved urgently in the process of preparing catalysts by hydrothermal reaction. Summary of the Invention

[0006] To address the shortcomings of the prior art, the present invention first acid-etches titanium felt to obtain acid-treated titanium felt, then mixes and disperses a ruthenium source and a composite surfactant to form a mixed reaction solution, and finally, the acid-treated titanium felt and the mixed reaction solution are mixed and hydrothermally reacted to obtain a composite catalyst, thereby solving the technical problems raised in the background art. Specifically, the technical solution of the present invention includes the following:

[0007] A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction, the synthesis method comprising the following steps:

[0008] The titanium felt is subjected to ultrasonic treatment to obtain pretreated titanium felt;

[0009] The pretreated titanium felt is subjected to acid etching treatment with an oxalic acid solution to obtain an acid-treated titanium felt;

[0010] The acid-treated titanium felt, the mixed reaction liquid and the reaction solvent are mixed and then subjected to a hydrothermal reaction to obtain a composite catalyst.

[0011] Furthermore, the area of the titanium felt is 1 cm 2 .

[0012] Furthermore, the ultrasonic treatment step includes sequentially ultrasonic cleaning with acetone for 15 minutes, ultrasonic cleaning with ethanol for 15 minutes, and ultrasonic cleaning with deionized water for 15 minutes.

[0013] Furthermore, the mass fraction of the oxalic acid solution is 5%.

[0014] Furthermore, the acid etching conditions include an acid etching temperature of 60° C. and an acid etching time of 40 min.

[0015] Furthermore, the mixed reaction liquid is obtained by mixing and dispersing a composite surfactant, a ruthenium source and deionized water in a weight ratio of 0.05:1.5:150.

[0016] Furthermore, the composite surfactant is composed of hexadecyltrimethylammonium bromide and polyvinylpyrrolidone mixed in a weight ratio of 2:1.

[0017] Furthermore, the ruthenium source includes ruthenium trichloride.

[0018] Furthermore, the reaction solvent is a 3% by mass hydrochloric acid solution.

[0019] Furthermore, the weight ratio of the acid-treated titanium felt, the mixed reaction liquid and the reaction solvent is 1:200:300.

[0020] Furthermore, the conditions of the hydrothermal reaction include a reaction temperature of 200° C. and a reaction time of 10 h.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention first subjects titanium felt to acid etching to obtain acid-treated titanium felt. Acid etching can increase the surface roughness of the titanium felt, helping to improve the reaction contact area and reaction efficiency. A ruthenium source and a composite surfactant are then mixed and dispersed to form a mixed reaction liquid. Compared to a single surfactant, the composite surfactant can further reduce surface energy and promote dispersion. Finally, the acid-treated titanium felt and the mixed reaction liquid are mixed and subjected to a hydrothermal reaction to obtain a composite catalyst. The synergistic effect of acid etching and the composite surfactant increases the Ru loading capacity and electrochemical performance of the prepared composite catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a SEM characterization image of the composite catalyst prepared in Example 1 of the present invention;

[0024] Figure 2 This is the EDS characterization diagram of the composite catalyst prepared in Example 1 of the present invention;

[0025] Figure 3 This is a graph showing the electrochemical performance of the composite catalyst prepared in Example 1 of the present invention;

[0026] Figure 4 This is a SEM characterization image of the composite catalyst prepared in Comparative Example 1 of the present invention;

[0027] Figure 5 This is the EDS characterization diagram of the composite catalyst prepared in Comparative Example 1 of the present invention;

[0028] Figure 6This is a graph showing the electrochemical performance of the composite catalyst prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions of the present invention through the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available or can be prepared by known methods.

[0031] Preparation Example 1:

[0032] The preparation method of the mixed reaction solution specifically includes the following steps:

[0033] 0.05 parts by weight of a composite surfactant (composed of hexadecyltrimethylammonium bromide and polyvinylpyrrolidone mixed in a weight ratio of 2:1), 1.5 parts by weight of ruthenium trichloride and 150 parts by weight of deionized water were weighed and mixed, and then subjected to an ultrasonic dispersion treatment at a power of 200 W for 20 minutes to obtain a mixed reaction liquid.

[0034] Preparation Example 2:

[0035] The preparation method of the mixed reaction solution specifically includes the following steps:

[0036] 1.5 parts by weight of ruthenium trichloride and 150 parts by weight of deionized water were weighed and mixed, and then subjected to ultrasonic dispersion treatment at a power of 200 W for 20 minutes to obtain a mixed reaction liquid.

[0037] Example 1:

[0038] A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction process, specifically comprising the following steps:

[0039] Set the area size to 1cm 2 The titanium felt was first completely immersed in an acetone solution, then cleaned in an ultrasonic cleaner at 400W for 15 minutes. After cleaning, the acetone solution was replaced with an ethanol solution, and cleaning was continued at 400W for 15 minutes. Finally, the ethanol solution was replaced with deionized water and cleaned at 400W for 15 minutes. After ultrasonic cleaning, the cleaned titanium felt was removed and rinsed with deionized water. It was then placed in a vacuum drying oven at 55°C to remove water to obtain the pretreated titanium felt.

[0040] The pretreated titanium felt was completely immersed in 50 mL of a 5% oxalic acid solution and heated to 60°C for 40 minutes. After etching, the felt was removed and rinsed with deionized water until the pH of the rinse water was neutral. The felt was then dried in a vacuum drying oven at 55°C to remove water and obtain the acid-treated titanium felt.

[0041] The acid-treated titanium felt, the mixed reaction liquid obtained in Preparation Example 1 and a 3% hydrochloric acid solution were placed together in a polytetrafluoroethylene liner in a weight ratio of 1:200:300, and then placed in a stainless steel reactor. The stainless steel reactor was then heated to 200°C and reacted for 10 hours. After the reaction was completed, it was cooled to room temperature and the acid-treated titanium felt after the reaction was obtained by separation. It was first rinsed with anhydrous ethanol and finally rinsed with deionized water. It was then placed in a vacuum drying oven and dried at 50°C to obtain a composite catalyst, completing the preparation. SEM test characterization and EDS test characterization were then carried out, and the results are shown in FIG. Figure 1 and Figure 2 , and then conduct LSV test characterization, the results are shown in Figure 3 Note: SEM and EDS characterizations are used to verify the loading capacity of the catalyst, while LSV characterizations are used to verify the electrochemical performance of the catalyst.

[0042] Comparative Example 1:

[0043] A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction process, specifically comprising the following steps:

[0044] Set the area size to 1cm 2 The titanium felt was first completely immersed in an acetone solution, then cleaned in an ultrasonic cleaner at 400W for 15 minutes. After cleaning, the acetone solution was replaced with an ethanol solution, and cleaning was continued at 400W for 15 minutes. Finally, the ethanol solution was replaced with deionized water and cleaned at 400W for 15 minutes. After ultrasonic cleaning, the cleaned titanium felt was removed and rinsed with deionized water. It was then placed in a vacuum drying oven at 55°C to remove water to obtain the pretreated titanium felt.

[0045] The pretreated titanium felt was completely immersed in 50 mL of a 5% oxalic acid solution and heated to 60°C for 40 minutes. After etching, the felt was removed and rinsed with deionized water until the pH of the rinse water was neutral. The felt was then dried in a vacuum drying oven at 55°C to remove water and obtain the acid-treated titanium felt.

[0046] The acid-treated titanium felt, the mixed reaction liquid obtained in Preparation Example 2 and a 3% hydrochloric acid solution were placed together in a polytetrafluoroethylene liner in a weight ratio of 1:200:300, and then placed in a stainless steel reactor. The stainless steel reactor was then heated to 200°C and reacted for 10 hours. After the reaction was completed, it was cooled to room temperature and the acid-treated titanium felt after the reaction was obtained by separation. It was first rinsed with anhydrous ethanol and finally rinsed with deionized water. It was then placed in a vacuum drying oven and dried at 50°C to obtain a composite catalyst, completing the preparation. SEM test characterization and EDS test characterization were then carried out, and the results are shown in FIG. Figure 4 and Figure 5 , and then conduct LSV test characterization, the results are shown in Figure 6 Note: SEM and EDS characterizations are used to verify the loading capacity of the catalyst, while LSV characterizations are used to verify the electrochemical performance of the catalyst.

[0047] in conclusion:

[0048] (1) Pass Figure 1 、 Figure 2 and Figure 4 、 Figure 5 From the comparison, it can be found that the loading amount of Ru on the composite catalyst prepared in Example 1 of the present invention is significantly increased compared with the loading amount of Ru on the composite catalyst prepared in Comparative Example 1, indicating that the preparation method of the present invention can significantly increase the content of Ru on the catalyst, and the increase in Ru content is conducive to electrocatalytic hydrogen evolution.

[0049] (2) Pass Figure 3 and Figure 6 From the comparison, it can be found that the electrochemical performance of the composite catalyst prepared in Example 1 of the present invention is significantly improved compared with the electrochemical performance of the composite catalyst prepared in Comparative Example 1. The higher electrochemical performance helps to improve the catalytic activity and catalytic efficiency of the composite catalyst.

[0050] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction, characterized in that: The synthesis method comprises the following steps: The titanium felt is subjected to ultrasonic treatment to obtain pretreated titanium felt; The pretreated titanium felt is subjected to acid etching treatment with an oxalic acid solution to obtain an acid-treated titanium felt; The acid-treated titanium felt, the mixed reaction liquid and the reaction solvent are mixed and then subjected to a hydrothermal reaction to obtain a composite catalyst.

2. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The area of the titanium felt is 1 cm 2 .

3. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The ultrasonic treatment step includes sequentially performing ultrasonic cleaning with acetone for 15 minutes, ultrasonic cleaning with ethanol for 15 minutes, and ultrasonic cleaning with deionized water for 15 minutes.

4. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The mass fraction of the oxalic acid solution is 5%.

5. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The acid etching conditions include an acid etching temperature of 60° C. and an acid etching time of 40 minutes.

6. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The mixed reaction liquid is obtained by mixing and dispersing a composite surfactant, a ruthenium source and deionized water in a weight ratio of 0.05:1.5:

150.

7. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 6, characterized in that: The composite surfactant is prepared by mixing cetyltrimethylammonium bromide and polyvinylpyrrolidone in a weight ratio of 2:

1.

8. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 6, characterized in that: The ruthenium source includes ruthenium trichloride.

9. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The weight ratio of the acid-treated titanium felt, the mixed reaction liquid and the reaction solvent is 1:200:

300.

10. A synthesis method for improving catalyst loading and electrochemical performance during a hydrothermal reaction according to claim 1, characterized in that: The conditions of the hydrothermal reaction include a reaction temperature of 200° C. and a reaction time of 10 h.

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