Low-crystallinity TiO2 loaded Pt monatomic catalyst and preparation method thereof

Abstract

The invention relates to the technical field of preparation of monatomic catalysts, and discloses a low-crystallinity TiO2 loaded Pt monatomic catalyst and a preparation method thereof, and the preparation method comprises the following steps: S1, adding 6 g of ethanol, 1 g of hydrochloric acid and 8.9 g of tetrabutyl titanate into a beaker in sequence; according to the low-crystallinity TiO2-loaded Pt monatomic catalyst and the preparation method, when a TiO2 carrier is prepared, a one-step solution mixing method and a sol-gel method are adopted, only 60 DEG C low-temperature drying is needed during drying, in the monatomic loading step, only the prepared TiO2 powdery carrier needs to be immersed in an ethylene glycol solution of H2PtCl6-6H2O, Pt monatomic can be loaded on the surface of the TiO2 carrier, and the catalyst has the advantages that the catalyst is simple in preparation process, low in cost and easy to implement. According to the present invention, the raw materials for preparing the low crystallinity TiO2 carrier comprise butyl titanate, ethanol, a small amount of hydrochloric acid and water, such that the cost is low, and the drying temperatures are 60 DEG C and 80 DEG C so as to substantially reduce the production cost, achieve the efficient utilization of the noble metal, and ensure the production of the catalyst at the low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of single-atom catalysts, and particularly to a low-crystallinity TiO 2 supported Pt single-atom catalyst and its preparation method. Background Art

[0002] As a clean energy with high calorific value and good renewable performance, hydrogen energy provides a reliable solution to future energy and environmental problems. Hydrogen produced by coupling renewable energy (such as photovoltaic and wind power) with electrolyzed water is called "green hydrogen", which can convert abundant but discrete energy into concentrated and stable chemical energy, and has incomparable huge advantages in energy storage. Traditional fossil energy not only faces the problem of limited reserves, but also produces a large amount of pollutants during use, causing serious damage to the environment. Therefore, the development of clean and efficient new energy technologies has become a research hotspot in the global energy field. Electrolytic water hydrogen production is an effective clean energy technology and plays an important role in renewable energy hydrogen production. Compared with other hydrogen production methods, electrolytic water hydrogen production has the advantages of no pollution, high efficiency, and large-scale production.

[0003] However, traditional electrolytic water technologies have some problems, such as high energy consumption and low catalyst activity. In addition, the kinetics of the anodic oxygen evolution reaction (OER) and the cathodic hydrogen evolution reaction (HER) during the electrolytic water process are relatively sluggish, and catalysts are needed to accelerate the reaction. Advanced HER catalysts are Pt-based materials, which have limitations as noble metal catalysts. These noble metal catalysts have problems such as high cost and limited reserves, restricting their large-scale application.

[0004] In recent years, single-atom catalysts (SACs) with active metals dispersed at the atomic level on supports have become a new frontier in the field of catalytic science and attracted extensive research attention. Single-atom catalysts can maximize the utilization rate of metal atoms and possess the advantages of both homogeneous and heterogeneous catalysts. They not only show great potential to bridge the gap between the two, but also are applied in many important energy reactions and the synthesis of industrial chemicals. In addition, the single and homogeneous nature of their structures also helps to comprehensively understand the relationship between catalyst structure and performance, and achieve rational catalyst design for atomic-level target reactions. Therefore, a low-crystallinity TiO 2 supported Pt single-atom catalyst and its preparation method are proposed to solve the above problems. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] Aiming at the current difficult problems in the industrial preparation of single-atom catalysts, a low-crystallinity TiO 2Pt single-atom loaded catalyst and preparation method thereof. The method has the advantages of simple and easily available raw materials, low cost, low toxicity, etc. The preparation process has the advantages of low pollutant emission, low energy consumption, high yield, etc., solving the problems of low-cost large-scale production of single-atom catalysts, long production cycle and low yield.

[0007] (II) Technical solution

[0008] To achieve the above object, the present invention provides the following technical solution: a preparation method of a low-crystallinity TiO 2 Pt single-atom loaded catalyst, comprising the following steps:

[0009] S1. Add 6 g of ethanol, 1 g of hydrochloric acid and 8.9 g of tetrabutyl titanate into a beaker in sequence, and stir for 2 hours until the mixture is completely uniform;

[0010] S2. Drop in 9 ml of distilled water and stir vigorously until a gel is formed to generate 60TiO 2 ;

[0011] S3. Then 60TiO 2 is calcined in an air atmosphere at 160 and 260 °C for 12 h to obtain 160TiO 2 and 260TiO 2 respectively. After that, use a grinding device to grind sufficiently to make the carrier into a uniform fine powder;

[0012] S4. Load Pt single atoms. Weigh 20 mg of 60TiO 2 carrier powder and put it into a bottle, then add 600 μL of H 2 PtCl 6 -6H 2 O solution to obtain a dispersion, and perform ultrasonic treatment on the dispersion through an ultrasonic device;

[0013] S5. After the obtained powder is adsorbed for 24 h, aspirate the supernatant, and dry the precipitated powder in a blast drying oven at 80 °C for 12 h to obtain 30Pt / 60TiO 2 , and prepare 30Pt / 160TiO 2 and 30Pt / 260TiO 2 in the same way.

[0014] Preferably, in S1, 1 g of hydrochloric acid is first added to ethanol, and then added to tetrabutyl titanate and stirred evenly to prevent the hydrolysis of tetrabutyl titanate.

[0015] Preferably, the 9 ml of distilled water in S2 must be added drop by drop to prevent local rapid hydrolysis and crystallization. During the whole dropping process, the solution must be stirred strongly.

[0016] Preferably, the grinding device in S3 is a ball mill, which grinds the sample into extremely fine powder.

[0017] Preferably, the ultrasonic device in S4 is an ultrasonic machine.

[0018] Preferably, the concentration of the H 2 PtCl 6 -6H 2 O solution in S4 is 30 mmol.

[0019] Preferably, the ultrasonic treatment of the dispersion liquid in S4 specifically means ultrasonicating the dispersion liquid in an ultrasonic machine for 5 minutes to ensure that the powder sample is evenly dispersed in the solution system.

[0020] Preferably, the catalyst after adsorption in S5 does not need to be washed. After drying in a blast drying oven at 80 °C, the sample is ground into extremely fine powder again using a ball mill.

[0021] Another technical problem to be solved by the present invention is to provide a low-crystallinity TiO 2 -supported Pt single-atom catalyst, which is prepared by a preparation method of a low-crystallinity TiO 2 -supported Pt single-atom catalyst.

[0022] (III) Beneficial effects

[0023] Compared with the prior art, the present invention provides a low-crystallinity TiO 2 -supported Pt single-atom catalyst and a preparation method, having the following beneficial effects:

[0024] 1. For the low-crystallinity TiO 2 -supported Pt single-atom catalyst and the preparation method, by adopting a one-step solution mixing method and a sol-gel method when preparing the TiO 2 support, only low-temperature drying at 60 °C is required during drying. In the single-atom loading step, only the prepared TiO 2 powder support needs to be immersed in an ethylene glycol solution of H 2 PtCl 6 -6H 2 O, and then the Pt single atoms can be loaded onto the surface of the TiO 2 support, thus achieving the purpose of a simple preparation method.

[0025] 2. For the low-crystallinity TiO 2 -supported Pt single-atom catalyst and the preparation method, by using the low-crystallinity TiO 2The raw materials for preparing the support are tetrabutyl titanate, ethanol, a small amount of hydrochloric acid and water, with low cost. The drying temperature is 60°C and 80°C, which greatly reduces the production cost. When loading single-atom Pt, the concentration of the impregnation solution used is calculated and experimentally ensured that the adsorption rate is above 98%, enabling efficient utilization of precious metals. The final loading amount of Pt single atoms is approximately around 3%, which ensures the production of this catalyst at a low cost.

[0026] 3. This low-crystallinity TiO 2 Supported Pt single-atom catalyst and its preparation method. By using the sol-gel method in the preparation of the support, there is basically no waste water and waste liquid discharge. During the stage of loading Pt single atoms, the Pt ions in the ethylene glycol solution of H 2 PtCl 2 PtCl 6 -6H 2 O are basically completely adsorbed, which reduces the difficulty of treating the waste liquid in this stage. In addition, the TiO 2 material has little environmental pollution. Even if this material is retired, the pollution caused to the environment is relatively small.

[0027] 4. This low-crystallinity TiO 2 Supported Pt single-atom catalyst and its preparation method. This catalyst has high catalytic activity, far exceeding that of commercial platinum-carbon catalysts, and has good stability. It can work for thousands of hours without obvious attenuation at a current density of 400 - 500 mA / cm², with a long lifespan and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the experimental process of the present invention;

[0029] Figure 2 is a schematic diagram of the HER performance, related Tafel curves, overpotential and comparison of overpotential of Pt / C, 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 in the electrolyte;

[0030] Figure 3 is a schematic diagram of the CV diagrams at different scanning rates and the corresponding double-layer capacitance (Cdl) of the first 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 of the present invention;

[0031] Figure 4 is a schematic diagram of the CV diagrams at different scanning rates and the corresponding double-layer capacitance (Cdl) of the second 30Pt / 60TiO 2 , 30Pt / 160TiO 2and 30Pt / 260TiO 2 CV diagrams at different scanning rates and schematic diagrams of the corresponding double-layer capacitance (Cdl);

[0032] Figure 5 For the third 30Pt / 60TiO in the present invention 2 、30Pt / 160TiO 2 and 30Pt / 260TiO 2 CV diagrams at different scanning rates and schematic diagrams of the corresponding double-layer capacitance (Cdl);

[0033] Figure 6 For 30Pt / 60TiO in the present invention 2 、30Pt / 160TiO 2 and 30Pt / 260TiO 2 Nyquist plots;

[0034] Figure 7 For 30Pt / 60TiO in the present invention 2 Schematic diagrams of potential cycling stability and potentiostatic stability in different electrolytes;

[0035] Figure 8 Schematic XPS spectra of the effective and ineffective 30Pt / 60TiO catalysts of the present invention in the Pt 4f and Ti 2p regions; 2

[0036] Figure 9 For 5Pt / 60TiO in the present invention 2 2 、10Pt / 60TiO 2 、20Pt / 60TiO 2 、40Pt / 60TiO 2 and 50Pt / 60TiO 2 Schematic diagrams of the HER performance of the samples in different electrolytes. Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the embodiments and drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0038] Example 1:

[0039] A preparation method of a Pt single-atom catalyst supported on low-crystallinity TiO 2 comprises the following steps:

[0040] S1. Add 6 g of ethanol, 1 g of hydrochloric acid, and 8.9 g of tetrabutyl titanate into a beaker in sequence, and stir for 2 hours until the mixture is completely homogeneous;

[0041] S2. Drop in 9 ml of distilled water and stir vigorously until a gel is formed to generate 60TiO 2 ;

[0042] S3. Use a grinding device to grind thoroughly to make the carrier into a uniform fine powder;

[0043] S4. Load Pt single atoms. Weigh 20 mg of the 60TiO 2 carrier powder and put it into a bottle, then add 600 μL of H 2 PtCl 6 -6H 2 O solution with a concentration of 30 mmol to obtain a dispersion, and perform ultrasonic treatment on the dispersion through an ultrasonic device;

[0044] S5. After the obtained powder is adsorbed for 24 h, aspirate the supernatant, and dry the precipitated powder in a blast drying oven at 80 °C for 12 h to obtain 30Pt / 60TiO 2 .

[0045] Example 2:

[0046] A preparation method of a low-crystallinity TiO 2 supported Pt single-atom catalyst, comprising the following steps:

[0047] S1. Add 6 g of ethanol, 1 g of hydrochloric acid, and 8.9 g of tetrabutyl titanate into a beaker in sequence, and stir for 2 hours until the mixture is completely homogeneous;

[0048] S2. Drop in 9 ml of distilled water and stir vigorously until a gel is formed to generate 60TiO 2 ;

[0049] S3. Then, 60TiO 2 is calcined in an air atmosphere at 160 °C for 12 h to obtain 160TiO 2 , and then use a grinding device to grind thoroughly to make the carrier into a uniform fine powder;

[0050] S4. Load Pt single atoms. Weigh 20 mg of the low-crystallinity 160TiO 2 carrier powder and put it into a bottle, then add 600 μL of H 2 PtCl 6 -6H 2 O solution with a concentration of 30 mmol to obtain a dispersion, and perform ultrasonic treatment on the dispersion through an ultrasonic device;

[0051] S5. After adsorbing the obtained powder for 24 h, aspirate the supernatant, and dry the precipitated powder in a blast drying oven at 80 °C for 12 h to obtain 30Pt / 160TiO 2 .

[0052] Example 3:

[0053] A preparation method of a low-crystallinity TiO 2 supported Pt single-atom catalyst, comprising the following steps:

[0054] S1. Add 6 g of ethanol, 1 g of hydrochloric acid and 8.9 g of tetrabutyl titanate into a beaker in sequence, and stir for 2 hours until the mixture is completely homogeneous;

[0055] S2. Drop in 9 ml of distilled water and stir vigorously until a gel is formed to generate 60TiO 2 ;

[0056] S3. Subsequently, 60TiO 2 is calcined in an air atmosphere at 260 °C for 12 h to obtain 260TiO 2 , and then it is sufficiently ground by a grinding device to make the carrier into a uniform fine powder;

[0057] S4. Load Pt single atoms. Weigh 20 mg of the low-crystallinity 260TiO 2 carrier powder and put it into a bottle, then add 600 μL of H 2 PtCl 6 -6H 2 O solution to obtain a dispersion, and ultrasonically treat the dispersion by an ultrasonic device;

[0058] S5. After adsorbing the obtained powder for 24 h, aspirate the supernatant, and dry the precipitated powder in a blast drying oven at 80 °C for 12 h to obtain 30Pt / 260TiO 2 .

[0059] According to the above three examples, it can be concluded that as Figure 1 shown, 60TiO 2 captures Pt and is heated in an oven at 80 °C for 12 hours. This process causes the complete reduction of Pt ions to metallic Pt, which exists in the form of SA on the surface of 60TiO 2 . Using the same method, after 60TiO 2 is calcined in air at 160 °C for 12 hours, Pt is loaded onto 160TiO 2 . In this case, the platinum sites exist in the form of small metal particles. After 60TiO 2 is calcined at 260 °C for 12 hours, larger Pt particles are loaded onto 260TiO 2Above, the crystallinity of TiO 2 varies with the calcination temperature. TiO with low crystallinity 2 tends to disperse Pt into single atoms, and the particle size of 60TiO 2 is small. With the increase of the crystallinity of 160TiO 2 and 260TiO 2 , the agglomeration phenomenon becomes more obvious. It should be noted that the same effect can also be achieved by expanding the raw materials in equal proportion.

[0060] Experimental Example 1: Replace 600 μL of chloroplatinic acid solution with a concentration of 30 mmol with 600 μL of chloroplatinic acid solution with concentrations of 5 / 10 / 20 / 40 / 50 mmol to prepare catalyst samples of 5Pt / 60TiO 2 , 10Pt / 60TiO 2 , 20Pt / 60TiO 2 , 40Pt / 60TiO 2 and 50Pt / 60TiO 2 .

[0061] Specifically, test the HER performance in different electrolytes such as 1M phosphate buffer solution (PBS, pH = 7), 0.5M H 2 SO 4 (pH = 0), 1.0M KOH (pH = 14). The electrochemical performance results are as shown in Figure 2 and Figure 9 . The experimental results show that when the concentration of chloroplatinic acid solution is 30 mmol, the catalyst activity is the best.

[0062] Furthermore, the catalyst 30Pt / 60TiO 2 exhibits strong HER activity over the entire pH range. Specifically, in 1M PBS, 0.5M H 2 SO 4 and 1.0M KOH electrolytes, when the current density is 10 mA / cm 2 , it generates overpotentials of 8.8, 20, and 13 mV respectively. In addition, this catalyst is stable for 200 h at -100 mA / cm 2 .

[0063] Experimental Example 2: As shown in Figures 3 - 4 , calculate 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2The electrochemically active surface area (ECSA) of the three samples in neutral, acidic, and alkaline electrolytes. The calculation formula for the electrochemically active surface area is: ECSA = Cdl / Cs, where Cdl is the double-layer capacitance and Cs is the planar capacitance of the metal surface (40 μF / cm 2 ), 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 Cyclic voltammograms at a scan rate of 40 - 120 mV s-1 in 1 m PBS electrolyte. The Cdl values of 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 are 5.3, 4.3, and 4.0 mF / cm 2 respectively. With the increase in the crystallinity of the TiO 2 support, the ECSA shows a downward trend. These results indicate that 30Pt / 60TiO 2 has higher catalytic activity and specific surface area, and can generate a larger ECSA. The Cdl values of 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 in 0.5 M H 2 SO 4 are 5.7, 3.3, and 3.4 mF / cm 2 respectively. It can be seen that the ECSA of 30Pt / 60TiO 2 is the highest.

[0064] Furthermore, as Figure 5 shown, the Cdl values of the same electrode in 1 M KOH are 7.5, 3.5, and 1.7 mF / cm 2 respectively. The results are similar to those of the tests in neutral and acidic electrolytes, indicating that with the increase in the crystallinity of the support, the ECSA of the material gradually decreases.

[0065] Experimental Example 3: Analyze the resistance of 30Pt / 60TiO 2 , 30Pt / 160TiO 2 and 30Pt / 260TiO 2 in three different pH electrolytes. As Figure 6 shown, the order of the charge transfer resistance from large to small is: 30Pt / 260TiO 2 > 30Pt / 160TiO 2 > 30Pt / 60TiO 2, The experimental results show that the high catalytic activity of the SA active site and the porous structure of 30Pt / 60TiO 2 contribute to the reaction and mass transfer, thereby improving the total conductivity of the electrode. In addition, the excellent electron transfer efficiency enables the effective transfer of charges to the active site, ultimately enhancing the catalytic performance of the catalyst.

[0066] Furthermore, as Figure 7 shown, after 3000 cv cycles, the LSV curves of 30Pt / 60TiO 2 in neutral, acidic, and alkaline electrolytes show no obvious change compared with the initial ones. After 200 hours of testing, although the initial test current density in the chronoamperometry test is -100 mA / cm 2 , the sample currents in all three electrolytes do not decrease significantly. 30Pt / 60TiO 2 exhibits good stability in neutral electrolyte. During the whole test process, except for the introduction of the electrolyte, there are no obvious fluctuations in the test curve. The results show that 30Pt / 60TiO 2 has excellent stability for HER in neutral, acidic, and alkaline electrolytes.

[0067] Furthermore, as Figure 8 shown, after the stability test, XPS test is carried out on 30Pt / 60TiO 2 catalyst. Compared with the catalyst before the test, the electronic structure of the sample remains relatively unchanged, indicating that the stability test under high current does not change the nature of the catalyst. The above results show that 30Pt / 60TiO 2 catalyst has good structural stability and chemical stability.

[0068] In summary, for the low-crystallinity TiO 2 supported Pt single-atom catalyst and its preparation method, when preparing the TiO 2 support, a one-step solution mixing method and a sol-gel method are adopted, and only low-temperature drying at 60 °C is required during drying. In the single-atom loading step, only the prepared TiO 2 powdered support needs to be immersed in the ethylene glycol solution of H 2 PtCl 6 -6H 2 O, then the Pt single atoms can be loaded onto the surface of the TiO 2 support, thus achieving the purpose of a simple preparation method. By using the low-crystallinity TiO 2The raw materials for carrier preparation are tetrabutyl titanate, ethanol, a small amount of hydrochloric acid and water, with a relatively low cost. The drying temperature is 60°C and 80°C, which greatly reduces the production cost. When loading single atoms, the concentration of the impregnation solution used is calculated and experimented to ensure that the adsorption rate is above 98%, enabling efficient utilization of precious metals. The final loading amount of Pt single atoms is approximately 3%, which ensures the production of this catalyst at a relatively low cost.

[0069] Moreover, by using the sol-gel method in the preparation of the TiO 2 carrier, there is basically no waste water or waste liquid discharge. At the stage of loading Pt single atoms, the Pt ions in the ethylene glycol solution of H 2 PtCl 6 -6H 2 O are basically completely adsorbed, which reduces the difficulty of treating the waste liquid at this stage. In addition, the TiO 2 material has little environmental pollution. Even when this material is retired, the pollution caused to the environment is relatively small. This catalyst has high catalytic activity, far exceeding that of commercial platinum-carbon catalysts, and good stability. At a current density of 400 - 500 mA / cm², it can work for thousands of hours without obvious attenuation, with a long lifespan and high efficiency, solving the problems of existing single-atom catalysts that cannot be produced at low cost on a large scale, have a long production cycle and low yield.

[0070] The above-described embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

[0071] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst, characterized in that: The following steps are involved: S1. Add 6 g of ethanol, 1 g of hydrochloric acid and 8.9 g of tetrabutyl titanate into a beaker in sequence and stir for 2 hours until the mixture is completely uniform; S2, add 9 ml of distilled water and stir vigorously until a gel is formed to generate 60TiO2; S3, then calcining 60TiO2 in an air atmosphere at 160 and 260°C for 12h to obtain 160TiO2 and 260TiO2 respectively, and then fully grinding it using a grinding device to make the carrier into a uniform fine powder; S4, loading Pt single atoms, weighing 20 mg of 60TiO2 carrier powder and putting it into a bottle, then adding 600 μL of H2PtCl6-6H2O solution to obtain a dispersion, and ultrasonically treating the dispersion with an ultrasonic device; S5. After the obtained powder is adsorbed for 24 hours, the upper clear liquid is aspirated and the precipitated powder is dried in a forced air drying oven at 80°C for 12 hours to obtain 30Pt / 60TiO2. 30Pt / 160TiO2 and 30Pt / 260TiO2 are prepared by the same method.

2. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: In S1, 1 g of hydrochloric acid is first added to ethanol, and then added to tetrabutyl titanate and stirred evenly, so as to prevent hydrolysis of tetrabutyl titanate.

3. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The 9 ml of distilled water in S2 must be added dropwise to prevent local rapid hydrolysis and crystallization. During the entire dropping process, the solution must be vigorously stirred.

4. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The grinding device in S3 is a ball mill, which grinds the sample into extremely fine powder.

5. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The ultrasonic device in S4 is an ultrasonic machine.

6. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The concentration of the H2PtCl6-6H2O solution in the S4 is 30 mmol.

7. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The ultrasonic treatment of the dispersion in S4 is specifically to ultrasonicate the dispersion in an ultrasonic machine for 5 minutes to ensure that the powder sample is evenly dispersed in the solution system.

8. The method for preparing a low-crystallinity TiO2-supported Pt single-atom catalyst according to claim 1, characterized in that: The catalyst after adsorption in S5 does not need to be washed. After drying in a forced air drying oven at 80° C., the sample is ground into extremely fine powder using a ball mill again.

9. A low crystallinity TiO2-supported Pt single-atom catalyst, characterized in that: The catalyst is prepared by the method for preparing a low-crystallinity TiO2-loaded Pt single-atom catalyst as described in any one of claims 1 to 8.

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