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

Abstract

The invention is suitable for the technical field of material chemistry, 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 an iodine element to obtain a suspension; placing the suspension in a reactor for reaction to obtain iodine-rich adsorption porous carbon; and cooling, cleaning and drying the iodine-enriched adsorbed porous carbon to obtain the porous carbon-based iodine-enriched catalyst. The iodine-doped porous carbon material, namely the porous carbon-based iodine-rich catalyst, is successfully prepared by reacting porous carbon with a compound containing an iodine element under a high-temperature condition. The method is conventional in equipment, simple to operate, low in cost and suitable for industrial production. The prepared porous carbon-based iodine-rich catalyst has mutually communicated porous structures and abundant surface microstructures. Performance tests show that the catalyst shows excellent catalytic activity, rapid dynamic property and good stability in water electrolysis hydrogen production, and has high application potential.

Description

Technical Field

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

[0002] Porous carbon is a two-dimensional periodic carbonaceous new material formed by connecting sp 2 hybridized benzene rings with sp hybridized triple bonds. It has a natural pore structure, band gap, excellent conductivity and electron mobility, as well as good mechanical properties and chemical stability. Its special electronic structure properties and excellent semiconductor properties close to silicon make it show great application potential in the fields of catalysis, electronic devices, semiconductors and energy storage.

[0003] Modification with foreign elements can change the electronic structure of porous carbon, effectively regulate the band gap of porous carbon, and change the conductivity of porous carbon. At the same time, it can effectively increase the reactivity of porous carbon itself and induce the generation of new functions. By introducing lone pair electrons through heteroatom doping, the electronic properties of porous carbon can be regulated and additional functional groups can be generated on its surface, which not only improves its intrinsic activity, but also increases wettability and promotes the full contact between the electrode material and the electrolyte.

[0004] At present, nitrogen-doped porous carbon has been widely studied and proven to have high catalytic activity. However, there is no report on the preparation method of porous carbon-based iodine-rich catalysts. Therefore, developing a preparation method of porous carbon-based iodine-rich catalysts that is simple, easy to operate, green and environmentally friendly, uses conventional equipment, and is easy to industrialize is of great significance for significantly improving its electrochemical performance. For this reason, 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 proposed in the above background art.

[0006] The purpose of the present invention is achieved through the following technical solutions: A preparation method of a porous carbon-based iodine-rich catalyst includes the following steps: Step 1: Uniformly mix porous carbon with a compound containing iodine element to obtain a suspension; the mass ratio of porous carbon to the compound containing iodine element in the suspension is 0.001 - 20, such as 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 - 10.

[0007] Step 2: Place the suspension obtained in Step 1 in a reactor for reaction to obtain iodine-rich adsorbed porous carbon. The reaction temperature is 30~300°C, such as 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. The preferred reaction temperature is 80~280°C; the reaction time is 0.01~48h, such as 0.1h, 2h, 4.5h, 7h, 10h, 11h, 17h, 20h, 23h, 27h, 33h, 37h, 40h, 47h, etc. The preferred reaction time is 1~24h.

[0008] Step 3: After cooling the iodine-rich adsorbed porous carbon obtained in Step 2, wash it and dry it at 50°C for 10~60min to obtain a porous carbon-based iodine-rich catalyst. The cooling temperature is -60~30°C, such as -45°C, -30°C, -18°C, 0°C, 10°C, 15°C, 22°C, 25°C, 28°C, etc. The preferred cooling temperature is 0~25°C.

[0009] Furthermore, in Step 1, the porous carbon includes pure porous carbon or porous carbon grown on any template.

[0010] Furthermore, in Step 1, the iodine-containing compound 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, in the present invention, the iodine-containing compound is added in the form of elemental iodine, potassium iodide, and potassium iodate.

[0011] Furthermore, in Step 1, the concentration of the porous carbon is 0.001~60g / L, such as 0.01g / L, 0.1g / L, 0.5g / L, 1g / L, 1.5g / L, 3.2g / L, 5.15g / L, 6.88g / L, 13.2g / L, 15g / L, 18.9g / L, 28.2g / L, 30g / L, 35g / L, 42g / L, 50g / L, 55g / L, etc. The preferred concentration is 15g / L.

[0012] Furthermore, in Step 1, based on iodine element, the concentration of the iodine-containing compound solution is 0.001~20g / L, such as 0.01g / L, 0.15g / L, 0.215g / L, 0.3g / L, 6.5g / L, 8.5g / L, 9.2g / L, 11.8g / L, 13.1g / L, 14.5g / L, 17.8g / L, 19.2g / L, etc.

[0013] Furthermore, in Step 3, pure water is used for washing.

[0014] A porous carbon-based iodine-rich catalyst prepared by the preparation method described above. In the porous carbon-based iodine-rich catalyst, the porous carbon is a carbon material containing one or more of sp 2 , sp 3 or sp hybrid carbon atoms, and its pore size is adjustable; the iodine content of the porous carbon-based iodine-rich catalyst is controllable. The present invention can realize the regulation of the iodine content by adjusting the concentration of the porous carbon, the proportion of the iodine element-containing compound in the suspension in step 1, and the reaction temperature and reaction time in step 2; the control of the pore size is realized by adjusting the uniformity of the porous carbon in the suspension in step 1.

[0015] An application of the porous carbon-based iodine-rich catalyst described above in the electrolysis of water to produce hydrogen.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: By reacting porous carbon with a compound containing iodine element under high temperature conditions, the present invention successfully prepares an iodine-doped porous carbon material, namely a porous carbon-based iodine-rich catalyst. This method has conventional equipment, simple operation and low cost, and is suitable for industrial production. The prepared porous carbon-based iodine-rich catalyst has a mutually connected porous structure and a rich surface microstructure. Performance tests show that the catalyst exhibits excellent catalytic activity, fast kinetic properties and good stability in the electrolysis of water to produce hydrogen, and has high application potential. Description of the Drawings

[0017] Figure 1 It is a scanning electron microscope (SEM) image of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0018] Figure 2 It is a high-resolution scanning electron microscope image of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0019] Figure 3 It is an XPS spectrum of the porous carbon-based iodine-rich catalyst prepared in Example 1.

[0020] Figure 4 It is a result graph of the performance study of the electrolysis of water to produce hydrogen of the porous carbon-based iodine-rich catalyst prepared in Example 1 in a 0.5 M H2SO4 electrolyte; where 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; c is the current-time curve graph of the porous carbon-based iodine-rich catalyst. Detailed Embodiments

[0021] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it should not be construed as a limitation on the scope of implementation of the present invention.

[0022] The present invention provides a preparation method of a porous carbon-based iodine-rich catalyst, and the method comprises the following steps: Step 1: Uniformly mix porous carbon with a compound containing iodine element to obtain a suspension; the mass ratio of porous carbon to the compound containing 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 iodine element is any one or a combination of at least two of iodine, iodine water, iodic acid and iodine-containing salts. Typically but not restrictively, in the present invention, the compound containing iodine element is added in the form of iodine, potassium iodide and potassium iodate. The concentration of the porous carbon is 0.001-60 g / L, preferably 15 g / L. Calculated by iodine element, the concentration of the compound solution containing iodine element is 0.001-20 g / L.

[0023] Step 2: Place the suspension obtained in Step 1 in a reactor and react at 30-300 °C for 0.01-48 h to obtain iodine-rich adsorbed porous carbon; the reaction temperature is preferably 80-280 °C; the reaction time is preferably 1-24 h.

[0024] Step 3: Cool the iodine-rich adsorbed porous carbon obtained in Step 2 to -60-30 °C (preferably 0-25 °C), wash it with pure water, and dry it at 50 °C for 10-60 min to obtain a porous carbon-based iodine-rich catalyst.

[0025] A porous carbon-based iodine-rich catalyst prepared by the preparation method described above, in the porous carbon-based iodine-rich catalyst, the porous carbon is a carbon material containing one or more of sp 2 、sp 3 or sp hybrid carbon atoms, and its pore size is adjustable; the iodine content of the porous carbon-based iodine-rich catalyst is controllable. The present invention can realize the regulation of the iodine content by adjusting the concentration of the porous carbon, the proportion of the compound containing iodine element in the suspension in Step 1, and the reaction temperature and reaction time in Step 2; the control of the pore size is realized by adjusting the uniformity of the porous carbon in the suspension in Step 1.

[0026] An application of the porous carbon-based iodine-rich catalyst described above in hydrogen production by electrolyzing water.

[0027] The following describes the specific implementation of the present invention in detail with specific examples.

[0028] Example 1: A preparation method of a porous carbon-based iodine-rich catalyst, comprising the following steps: 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, mix evenly to obtain a suspension; the mass ratio of porous carbon to iodine in the suspension is 0.1:10; Step 2: React the suspension obtained in Step 1 at 100 °C for 24 h to obtain iodine-rich adsorbed porous carbon; Step 3: Cool the iodine-rich adsorbed porous carbon obtained in Step 2 to 25 °C, wash it with pure water, and dry it at 50 °C for 40 min to obtain a porous carbon-based iodine-rich catalyst.

[0029] 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, a Hitachi S4800 scanning electron microscope (SEM) was used to observe the morphology of the catalyst, and corresponding images were taken. Figure 1 It shows the overall morphology of the catalyst (5 µm), demonstrating the preparation of a large-area porous carbon-based iodine-rich catalyst; Figure 2 It provides a detailed view at a higher resolution (3 nm), demonstrating that the porous carbon-based iodine-rich catalyst has an uneven, porous and rough surface structure. In addition, X-ray photoelectron spectroscopy (XPS) was performed using an ESCALab 250 Xi X-ray photoelectron spectrometer under the condition of 300 W Al Kα, and the results are as Figure 3 shown. It can be seen that there are obvious iodine element peaks in the figure, confirming 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.

[0030] Furthermore, the performance of the porous carbon-based iodine-rich catalyst prepared in Example 1 for hydrogen production by electrolyzing water in a 0.5 M H2SO4 electrolyte was evaluated, and the results are as Figure 4 shown in a~c. As can be seen from Figure 4 a, at the same applied potential, the porous carbon-based iodine-rich catalyst has a larger current density than pure porous carbon, indicating its better hydrogen production performance. As can be seen from Figure 4 b, the Tafel slope value of the porous carbon-based iodine-rich catalyst is smaller than that of pure porous carbon, proving its faster kinetic properties and better catalytic activity. As can be seen from Figure 4 c, after at least 40 hours of continuous hydrogen production test, the activity of the porous carbon-based iodine-rich catalyst hardly decreases, which fully demonstrates its excellent stability.

[0031] In summary, Example 1 successfully prepared a porous carbon-based iodine-rich catalyst, which showed excellent performance in hydrogen production by electrolyzing water.

[0032] The above is only the preferred embodiment of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent.

Claims

1. A preparation method of a porous carbon-based iodine-rich catalyst, characterized in that, It includes the following steps: Step 1: Uniformly mix porous carbon with a compound containing iodine element to obtain a suspension; The mass ratio of porous carbon to the compound containing iodine element in the suspension is 0.001 - 20; Step 2: Place the suspension obtained in Step 1 in a reactor and react at 30 - 300 °C for 0.01 - 48 h to obtain iodine-rich adsorbed porous carbon; Step 3: Cool the iodine-rich adsorbed porous carbon obtained in Step 2 to -60 - 30 °C, wash it, and dry it at 50 °C for 10 - 60 min to obtain a porous carbon-based iodine-rich catalyst.

2. The preparation method of the porous carbon-based iodine-rich catalyst according to claim 1, wherein In the said Step 1, the porous carbon includes pure porous carbon or porous carbon grown on any template.

3. The preparation method of the porous carbon-based iodine-rich catalyst according to claim 2, characterized in that, In the said Step 1, the compound containing iodine element is any one or a combination of at least two of iodine, iodine water, iodic acid and iodine-containing salts.

4. The preparation method of the porous carbon-based iodine-rich catalyst according to claim 3, characterized in that, In the said Step 1, the concentration of the porous carbon is 0.001 - 60 g / L.

5. The preparation method of the porous carbon-based iodine-rich catalyst according to claim 1, characterized in that, In the said Step 1, calculated by iodine element, the concentration of the compound solution containing iodine element is 0.001 - 20 g / L.

6. The preparation method of the porous carbon-based iodine-rich catalyst according to claim 1, characterized in that, In the said Step 3, pure water is used for washing.

7. A porous carbon-based iodine-rich catalyst prepared by the preparation method according to any one of claims 1 to 6, characterized in that, The porous carbon in the porous carbon-based iodine-rich catalyst is a carbon material containing one or more of sp 2 , sp 3 hybridized carbon atoms or a combination thereof.

8. Application of the porous carbon-based iodine-rich catalyst according to claim 7 in hydrogen production by electrolyzing water.

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