Preparation method and application of porous carbon-based iodine-rich catalyst

Abstract

The present invention is applicable to the field of material chemistry technology, and provides a preparation method and application of a porous carbon-based iodine-rich catalyst. The preparation method comprises the following steps: uniformly mixing porous carbon with a compound containing iodine element to obtain a suspension; placing the suspension in a reactor for reaction to obtain iodine-rich porous carbon; cooling, washing and drying the iodine-rich porous carbon to obtain a porous carbon-based iodine-rich catalyst. The present invention successfully prepares iodine-doped porous carbon materials, i.e., porous carbon-based iodine-rich catalysts, by reacting porous carbon with a compound containing iodine element under high temperature conditions. The method has conventional equipment, simple operation, low cost, and is suitable for industrial production. The prepared porous carbon-based iodine-rich catalyst has an interconnected porous structure and rich surface microstructure. Performance tests show that the catalyst exhibits excellent catalytic activity, rapid kinetic properties and good stability in hydrogen production by electrolysis of water, and has high application potential.

Description

Technical Field

[0001] The present invention belongs to the technical field of material chemistry, and in particular relates to a preparation method and application of a porous carbon-based iodine-rich catalyst. Background Art

[0002] Porous carbon is a kind of sp hybridized acetylenic bond. 2 This new two-dimensional periodic carbonaceous material, formed by hybridized benzene rings, exhibits a natural porous structure, a band gap, excellent electrical conductivity and electron mobility, as well as good mechanical properties and chemical stability. Its unique electronic structure and excellent semiconductor properties, approaching those of silicon, hold great potential for applications in catalysis, electronic devices, semiconductors, and energy storage.

[0003] Heterogeneous element modification can alter the electronic structure of porous carbon, effectively regulating its band gap and changing its conductivity. It can also effectively increase the reactivity of the porous carbon itself and induce the generation of new functionalities. Heteroatom doping, through the introduction of lone pairs of electrons, can modulate the electronic properties of porous carbon and generate additional functional groups on its surface, improving its intrinsic activity while also increasing wettability and promoting adequate contact between the electrode material and the electrolyte.

[0004] At present, nitrogen-doped porous carbon has been widely studied and has been shown to have high catalytic activity. However, there has been no report on the preparation method of porous carbon-based iodine-rich catalysts. Therefore, the development of a method for preparing a porous carbon-based iodine-rich catalyst that is simple, easy to operate, environmentally friendly, requires conventional equipment, and is easy to industrialize is of great significance for significantly improving its electrochemical performance. To this end, the present invention proposes a preparation method and application of a porous carbon-based iodine-rich catalyst. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method and application of a porous carbon-based iodine-rich catalyst, aiming to solve the problems raised in the above background technology.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A method for preparing a porous carbon-based iodine-rich catalyst comprises the following steps:

[0008] Step 1: uniformly mixing porous carbon and a compound containing iodine to obtain a suspension; the mass ratio of porous carbon to the compound containing iodine in the suspension is 0.001 to 20, for example, 0.1:1, 0.5:1, 0.9:1, 1.2:1, 1.5:1, 2:1, 4:1, 6:1, 8:1, 10:1, 11:1, 12:1, 15:1, 20:1, etc., preferably 0.1 to 10.

[0009] Step 2: placing the suspension obtained in step 1 in a reactor for reaction to obtain iodine-enriched porous carbon. The reaction temperature is 30-300°C, for example, 35°C, 60°C, 88°C, 120°C, 155°C, 170°C, 212°C, 235°C, 250°C, 270°C, 285°C, 296°C, etc., preferably the reaction temperature is 80-280°C; the reaction time is 0.01-48 hours, for example, 0.1 hour, 2 hours, 4.5 hours, 7 hours, 10 hours, 11 hours, 17 hours, 20 hours, 23 hours, 27 hours, 33 hours, 37 hours, 40 hours, 47 hours, etc., preferably the reaction time is 1-24 hours.

[0010] Step 3: Cooling the iodine-enriched porous carbon obtained in step 2, washing it, and drying it at 50°C for 10-60 minutes to obtain a porous carbon-based iodine-enriched catalyst. The cooling temperature is -60-30°C, for example, -45°C, -30°C, -18°C, 0°C, 10°C, 15°C, 22°C, 25°C, 28°C, etc., preferably 0-25°C.

[0011] Furthermore, in step 1, the porous carbon includes pure porous carbon or porous carbon grown on any template.

[0012] Furthermore, in step 1, the iodine-containing compound is any one of elemental iodine, iodine water, iodic acid, and iodine-containing salts, or a combination of at least two thereof. Typically, but not limiting, the iodine-containing compound is added in the form of elemental iodine, potassium iodide, or potassium iodate.

[0013] Furthermore, in step 1, the concentration of porous carbon is 0.001~60 g / L, for example, 0.01 g / L, 0.1 g / L, 0.5 g / L, 1 g / L, 1.5 g / L, 3.2 g / L, 5.15 g / L, 6.88 g / L, 13.2 g / L, 15 g / L, 18.9 g / L, 28.2 g / L, 30 g / L, 35 g / L, 42 g / L, 50 g / L, 55 g / L, etc., preferably 15 g / L.

[0014] Furthermore, in step 1, the concentration of the iodine-containing compound solution is 0.001 to 20 g / L, calculated as iodine, for example, 0.01 g / L, 0.15 g / L, 0.215 g / L, 0.3 g / L, 6.5 g / L, 8.5 g / L, 9.2 g / L, 11.8 g / L, 13.1 g / L, 14.5 g / L, 17.8 g / L, 19.2 g / L, etc.

[0015] Furthermore, in step 3, pure water is used for washing.

[0016] A porous carbon-based iodine-rich catalyst prepared according to the above-mentioned preparation method, wherein the porous carbon-based iodine-rich catalyst comprises sp 2 、sp 3 or one or more of sp hybridized carbon atoms, and the pore size is adjustable; the iodine content of the porous carbon-based iodine-rich catalyst is controllable. The present invention can achieve regulation of the iodine content by adjusting the concentration of the porous carbon in the suspension of step 1, the proportion of the iodine-containing compound, and the reaction temperature and reaction time of step 2; and the pore size is controlled by adjusting the uniformity of the porous carbon in the suspension of step 1.

[0017] An application of the porous carbon-based iodine-rich catalyst described above in hydrogen production by water electrolysis.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention successfully prepared iodine-doped porous carbon materials, i.e., porous carbon-based iodine-rich catalysts, by reacting porous carbon with a compound containing iodine under high temperature conditions. The method requires conventional equipment, is simple to operate, and is low-cost, making it suitable for industrial production. The prepared porous carbon-based iodine-rich catalyst has an interconnected porous structure and a rich surface microstructure. Performance tests have shown that the catalyst exhibits excellent catalytic activity, rapid kinetic properties, and good stability in hydrogen production by water electrolysis, and has high application potential. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a scanning electron microscope (SEM) image of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0021] Figure 2 This is a high-resolution scanning electron microscope image of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0022] Figure 3 This is the XPS spectrum of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0023] Figure 4 Graph showing the results of a study on the performance of the porous carbon-based iodine-rich catalyst prepared in Example 1 for hydrogen production by electrolysis of water in a 0.5 M H2SO4 electrolyte; wherein a is the linear polarization curve of the porous carbon-based iodine-rich catalyst and pure porous carbon; b is the Tafel slope of the porous carbon-based iodine-rich catalyst and pure porous carbon; and c is a current-time curve of the porous carbon-based iodine-rich catalyst. DETAILED DESCRIPTION

[0024] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0025] The present invention provides a method for preparing a porous carbon-based iodine-rich catalyst, the method comprising the following steps:

[0026] Step 1: Evenly mix the porous carbon and the compound containing the iodine element to obtain a suspension; the mass ratio of the porous carbon to the compound containing the iodine element in the suspension is 0.001~20; preferably 0.1~10. The porous carbon includes pure porous carbon or porous carbon grown on any template. The compound containing the iodine element is any one or a combination of at least two of elemental iodine, iodine water, iodic acid and iodine-containing salts. Typically but not restrictively, the compound containing the iodine element in the present invention is added in the form of elemental iodine, potassium iodide, or potassium iodate. The concentration of the porous carbon is 0.001~60g / L, preferably 15g / L. The concentration of the iodine-containing compound solution is 0.001~20g / L in terms of iodine element.

[0027] Step 2: placing the suspension obtained in step 1 in a reactor and reacting at 30-300° C. for 0.01-48 hours to obtain iodine-rich porous carbon; the reaction temperature is preferably 80-280° C.; and the reaction time is preferably 1-24 hours.

[0028] Step 3: Cool the iodine-rich porous carbon obtained in step 2 to -60~30°C (preferably 0~25°C), wash with pure water, and dry at 50°C for 10~60min to obtain a porous carbon-based iodine-rich catalyst.

[0029] A porous carbon-based iodine-rich catalyst prepared according to the above-mentioned preparation method, wherein the porous carbon-based iodine-rich catalyst comprises sp 2 、sp 3 or one or more of sp hybridized carbon atoms, and the pore size is adjustable; the iodine content of the porous carbon-based iodine-rich catalyst is controllable. The present invention can achieve regulation of the iodine content by adjusting the concentration of the porous carbon in the suspension of step 1, the proportion of the iodine-containing compound, and the reaction temperature and reaction time of step 2; and the pore size is controlled by adjusting the uniformity of the porous carbon in the suspension of step 1.

[0030] An application of the porous carbon-based iodine-rich catalyst described above in hydrogen production by water electrolysis.

[0031] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0032] Example 1: A method for preparing a porous carbon-based iodine-rich catalyst, comprising the following steps:

[0033] Step 1: Add 2 mL of a 15 g / L porous carbon solution to 200 mL of a solution containing 5 g / L potassium iodide and mix well to obtain a suspension; the mass ratio of porous carbon to elemental iodine in the suspension is 0.1:10;

[0034] Step 2: The suspension obtained in step 1 is reacted at 100° C. for 24 h to obtain iodine-rich porous carbon;

[0035] Step 3: The iodine-rich adsorbed porous carbon obtained in step 2 is cooled to 25° C., washed with pure water, and dried at 50° C. for 40 min to obtain a porous carbon-based iodine-rich catalyst.

[0036] In order to verify the structure and composition of the porous carbon-based iodine-rich catalyst prepared in Example 1, a variety of characterization methods were used. Specifically, the catalyst morphology was observed using a Hitachi S4800 scanning electron microscope (SEM) and the corresponding images were taken. Figure 1 The overall morphology of the catalyst (5µm) was demonstrated, demonstrating the successful preparation of a large-area porous carbon-based iodine-rich catalyst. Figure 2 The results provide a detailed view at a higher resolution (3 nm), proving that the porous carbon-based iodine-rich catalyst has an uneven, porous and rough surface structure. In addition, X-ray photoelectron spectroscopy (XPS) analysis was performed using an ESCALab 250 Xi X-ray photoelectron spectrometer under 300W Al Kα conditions. Figure 3 As shown, it can be seen that there is an obvious iodine peak in the figure, which confirms that the iodine element has been successfully modified on the porous carbon structure, realizing the successful preparation of the porous carbon-based iodine-rich catalyst.

[0037] Furthermore, the performance of the porous carbon-based iodine-rich catalyst prepared in Example 1 for hydrogen production by electrolysis of water in 0.5 M H2SO4 electrolyte was evaluated. Figure 4 As shown in a~c. Figure 4 As can be seen in Figure a, under the same applied potential, the porous carbon-based iodine-rich catalyst has a larger current density than pure porous carbon, indicating that it has better hydrogen production performance. Figure 4 As can be seen in Figure b, the Tafel slope of the porous carbon-based iodine-rich catalyst is smaller than that of pure porous carbon, proving that it has faster kinetic properties and better catalytic activity. Figure 4 As can be seen from Figure c, after at least 40 hours of continuous hydrogen production test, the activity of the porous carbon-based iodine-rich catalyst has hardly decreased, which fully demonstrates its excellent stability.

[0038] In summary, Example 1 successfully prepared a porous carbon-based iodine-rich catalyst, which showed excellent performance in hydrogen production by water electrolysis.

[0039] The above are only preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several variations and improvements can be made without departing from the concept of the present invention. These should also be regarded as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. Application of a porous carbon-based iodine-rich catalyst in hydrogen production by water electrolysis, characterized in that: The preparation method of the porous carbon-based iodine-rich catalyst comprises the following steps: Step 1: Add 2 mL of 15 g / L porous carbon solution to 200 mL of a solution containing 5 g / L potassium iodide and mix well to obtain a suspension; Step 2: The suspension obtained in step 1 is reacted at 100° C. for 24 h to obtain iodine-rich porous carbon; Step 3: The iodine-rich adsorbed porous carbon obtained in step 2 is cooled to 25° C., washed with pure water, and dried at 50° C. for 40 min to obtain a porous carbon-based iodine-rich catalyst.

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