Regeneration and activation method of deactivated black phosphorus catalyst

Abstract

The invention discloses a regeneration and activation method of an inactivated black phosphorus catalyst, and belongs to the technical field of phosphorus chemical new materials. The method comprises the following steps: placing an inactivated black phosphorus catalyst in a high-temperature area of a separator, separating an inert substance on the surface of the inactivated catalyst from the catalyst by controlling a separation temperature gradient in the separator under a vacuum or inert atmosphere sealing condition, then taking out the catalyst, and mixing the catalyst with iodine or an iodine compound, under the sealing condition of vacuum or inert atmosphere, reacting at 400-550 DEG C for 20-120 minutes, and cooling to 200-350 DEG C within 60-120 minutes, so as to realize the activation of the deactivated catalyst; and the activated catalyst has good reaction activity and very high cycle stability.

Description

Technical Field

[0001] The present invention relates to a method for regenerating an inactivated black phosphorus catalyst, belonging to the technical field of new phosphorus chemical materials. Background Art

[0002] Black phosphorus is an allotrope of phosphorus with a layered structure and has broad application prospects in the fields of sensing, energy storage, catalysis, flame retardancy, medicine, etc. CN108128761 B and CN110467165 A disclose a method for preparing high-purity black phosphorus by fixed-bed catalysis, which realizes the continuous preparation of black phosphorus through a fixed-bed reactor; CN117019188 A discloses a highly active catalyst for preparing black phosphorus and its preparation method, which further dopes and modifies the SnPI catalyst, greatly improving the catalytic activity of the SnPI catalyst and the growth kinetics of black phosphorus; in order to solve the problems that the powdered SnPI catalyst is difficult to recycle and the powder is easy to stack the bed layer, CN 116550349 A discloses a supported black phosphorus catalyst and its preparation method and application, which improves the specific surface area and structural strength of the catalyst by a loading method. However, after the above-mentioned catalysts are cycled a certain number of times, the catalytic activity will drop steeply and lose catalytic activity; therefore, how to regenerate the inactivated catalyst remains a difficult point that needs to be overcome urgently. Summary of the Invention

[0003] Aiming at the problem of inactivation of black phosphorus catalysts, the present invention provides a method for regenerating an inactivated black phosphorus catalyst. Through two-step treatment, the regeneration of the catalyst is realized. The activated catalyst exhibits high black phosphorus catalytic activity and cycle stability, and greatly reduces the use cost of the catalyst in the process of preparing black phosphorus.

[0004] The method for regenerating the inactivated black phosphorus catalyst of the present invention is as follows: 1. Place the inactivated black phosphorus catalyst in the high-temperature zone of the separator. Under the sealed condition of vacuum or inert atmosphere, use a tube furnace to separate the inert substances on the surface of the inactivated catalyst from the catalyst by controlling the separation temperature gradient in the separator; The temperature of the high-temperature zone in the separator is 500 - 540 °C. Controlling the separation temperature gradient in the separator means controlling the temperature difference between the low-temperature zone and the high-temperature zone to be 20 - 100 °C; The separator is a tubular separator; The inactivated black phosphorus catalyst is SnPI or SnPI-A (A is In, Te, Au, Bi, Pb, Ga, Ge, Se); 2. Mix the catalyst taken out from the separator with iodine or iodine compound, and under the sealed condition of vacuum or inert atmosphere, heat it to 400 - 550 °C and react for 20 - 120 min, then cool it to 200 - 350 °C within 60 - 120 min to achieve the activation of the deactivated catalyst.

[0005] The mass ratio of the catalyst to iodine or iodine compound is 50:1 - 5:1.

[0006] The iodine compound is selected from potassium iodide, sodium iodide, bismuth iodide, phosphorus iodide, tin tetraiodide, tin diiodide, and iodine bromide.

[0007] The beneficial effects of the present invention are as follows: 1. The catalyst regeneration method of the present invention can effectively restore the catalytic activity of the deactivated catalyst. When the yield of black phosphorus prepared by the catalyst drops below 15%, the catalyst regenerated by this method is used to prepare black phosphorus, and the yield of black phosphorus can be increased to more than 90%, up to 97.38% at most.

[0008] 2. The activation step of the present invention is simple, and the regenerated catalyst has high catalytic activity for black phosphorus and cycle stability. Description of the Drawings

[0009] Figure 1 It is the physical picture (upper picture) of the catalyst catalyzing the preparation of black phosphorus reaction 15 times in Example 1 and the statistical chart of black phosphorus yield (lower picture); Figure 2 It is the physical picture of the deactivated catalyst and the catalyst after activation with iodide in Example 1; Figure 3 It is the comparison chart of black phosphorus yields before and after catalyst activation; Figure 4 It is the physical picture (upper picture) of the activated catalyst and red phosphorus reacting to prepare black phosphorus in Example 1 and the statistical chart of black phosphorus yield (lower picture). Detailed Embodiments

[0010] The content of the present invention will be further illustrated by the following examples. However, these examples do not limit the protection scope of the present invention. The methods in the examples are all conventional methods without special instructions, and the reagents used are all conventional commercially available reagents or reagents prepared according to conventional methods without special instructions. Example 1

[0011] 1. Mix the catalyst SnPI and red phosphorus, react at a temperature gradient of 540 - 520 °C for 30 min, cool to room temperature, and then take out the black phosphorus; then mix the reacted catalyst and new red phosphorus, and carry out the reaction again according to the above reaction process. The physical picture of the reaction is as Figure 1As shown, when the cyclic reaction reaches 15 times, inert substances are deposited on the surface of the catalyst in the reactor, and the yield of black phosphorus decreases from 90% - 98% to 15.15%, indicating that the catalyst has been deactivated.

[0012] 2. Place the deactivated catalyst SnPI in the high-temperature zone of the tubular separator. After the tubular separator is evacuated and sealed, it is placed in a tube furnace. By heating with the tube furnace, the temperature in the high-temperature zone of the tubular separator is 520 °C and the temperature in the low-temperature zone is 500 °C (temperature difference of 20 °C). The inert substances on the surface of the deactivated catalyst are separated from the catalyst. Take out the deactivated catalyst SnPI after separating the inert substances and mix it with potassium iodide in a mass ratio of 20:1, place it in an activation tube, evacuate and seal it. Use a heater to heat the mixture to 540 °C. Potassium iodide reacts with the deactivated catalyst, and the reaction is kept at this temperature for 60 min. Then, it is cooled to 200 °C over 120 min. Take out the activation tube and let it cool naturally to room temperature to complete the reactivation of the deactivated catalyst; The physical object of the activated catalyst is as Figure 2 shown; 3. Use the activated catalyst to catalyze the preparation of black phosphorus from red phosphorus. The catalytic efficiency of the catalyst before and after activation is shown in Figure 3 , and the yield of black phosphorus increases from 15.15% to 97.38%, indicating that the deactivated catalyst has been activated. Further, the activated catalyst and red phosphorus are cyclically reacted to prepare black phosphorus. The results are as Figure 4 shown. When the activated catalyst continues to react for 30 times, it still has high catalytic activity for black phosphorus, and the yield of black phosphorus is 94.81%, indicating that potassium iodide has high activation performance for the deactivated catalyst, and the activated catalyst has high catalytic cycle stability for black phosphorus. Example 2

[0013] Place the deactivated catalyst SnPI - Se in the high-temperature zone of the tubular separator. Pass nitrogen into the tubular separator, seal it, and then place it in a tube furnace. By heating with the tube furnace, the temperature in the high-temperature zone of the tubular separator is 500 °C and the temperature in the low-temperature zone is 470 °C (temperature difference of 30 °C). The inert substances on the surface of the deactivated catalyst are separated from the catalyst. Take out the treated catalyst and mix it with bismuth iodide in a mass ratio of 50:1, put it into an activation tube, pass nitrogen into it and seal it. Use a heater to heat the activation tube containing the material to 550 °C. Bismuth iodide reacts with the deactivated catalyst, and the reaction is kept at this temperature for 20 min. Then, it is cooled to 350 °C over 80 min. Take out the activation tube and let it cool naturally to room temperature, which completes the reactivation step of the deactivated catalyst. When the activated catalyst is used to catalyze the preparation of black phosphorus, the yield of black phosphorus increases from 15.12% to 92.8%. Example 3

[0014] The deactivated catalyst SnPI-Au was placed in the high-temperature zone of a tubular separator. After the tubular separator was evacuated and sealed, it was placed in a tubular furnace. By heating with the tubular furnace, the temperature in the high-temperature zone of the tubular separator was 540 °C, and the temperature in the low-temperature zone was 440 °C (temperature difference 100 °C). The inert substances on the surface of the deactivated catalyst were separated from the catalyst. The treated catalyst and iodine were taken out and mixed in a mass ratio of 5:1 and placed in an activation tube, which was evacuated and sealed. The activation tube containing the material was heated to 520 °C using a heater. Iodine reacted with the deactivated catalyst, and the reaction was maintained at this temperature for 80 min. Subsequently, the temperature was decreased to 200 °C over 120 min. The activation tube was taken out and naturally cooled to room temperature, and the reactivation step of the deactivated catalyst was completed. The activated catalyst was used for the preparation of black phosphorus, and the yield of black phosphorus increased from 14.88% to 95.6%. Example 4

[0015] The deactivated catalyst SnPI-Pb was placed in the high-temperature zone of a tubular separator. Argon was introduced into the tubular separator and sealed, and then it was placed in a tubular furnace. By heating with the tubular furnace, the temperature in the high-temperature zone of the tubular separator was 540 °C, and the temperature in the low-temperature zone was 480 °C (temperature difference 60 °C). The inert substances on the surface of the deactivated catalyst were separated from the catalyst. The treated catalyst and tin tetraiodide were taken out and mixed in a mass ratio of 10:1 and placed in an activation tube. Argon was introduced into the activation tube and sealed. The activation tube containing the material was heated to 480 °C using a heater. Tin tetraiodide reacted with the deactivated catalyst, and the reaction was maintained at this temperature for 100 min. Subsequently, the temperature was decreased to 300 °C over 80 min. The activation tube was taken out and naturally cooled to room temperature, and the reactivation step of the deactivated catalyst was completed. The activated catalyst was used for the preparation of black phosphorus, and the yield of black phosphorus increased from 14.2% to 93.6%. Example 5

[0016] The deactivated catalyst SnPI-Ga was placed in the high-temperature zone of a tubular separator. After the tubular separator was evacuated and sealed, it was placed in a tubular furnace. By heating with the tubular furnace, the temperature in the high-temperature zone of the tubular separator was 520 °C, and the temperature in the low-temperature zone was 440 °C (temperature difference 80 °C). The inert substances on the surface of the deactivated catalyst were separated from the catalyst. The treated catalyst and potassium bromide were taken out and mixed in a mass ratio of 5:1 and placed in an activation tube, which was evacuated and sealed. The activation tube containing the material was heated to 400 °C using a heater. Potassium bromide reacted with the deactivated catalyst, and the reaction was maintained at this temperature for 120 min. Subsequently, the temperature was decreased to 350 °C over 60 min. The activation reactor was taken out and naturally cooled to room temperature, and the reactivation step of the deactivated catalyst was completed. The activated catalyst was used for the preparation of black phosphorus, and the yield of black phosphorus increased from 15.62% to 90.8%.

Claims

1. A method for regenerating an inactivated black phosphorus catalyst, characterized in that: Place the deactivated black phosphorus catalyst in the high-temperature zone of the separator. Under sealed conditions of vacuum or inert atmosphere, separate the inert substances on the surface of the deactivated catalyst from the catalyst by controlling the separation temperature gradient within the separator. Subsequently, take out the catalyst and mix it with iodine or iodine compound. Under sealed conditions of vacuum or inert atmosphere, place it at 400-550 °C for reaction for 20-120 min, and then cool it down to 200-350 °C within 60-120 min to achieve the activation of the deactivated catalyst. The temperature of the high-temperature zone in the separator is 500-540 °C. Controlling the separation temperature gradient within the separator means controlling the temperature difference between the low-temperature zone and the high-temperature zone to be 20-100 °C.

2. The method for regenerating the deactivated black phosphorus catalyst according to claim 1, wherein: The mass ratio of the deactivated catalyst to iodine or iodine compound is 50:1-5:

1.

3. The method for regenerating the deactivated black phosphorus catalyst according to claim 1, wherein: The deactivated black phosphorus catalyst is SnPI or SnPI-A, where A in SnPI-A is selected from In, Te, Au, Bi, Pb, Ga, Ge, Se.

4. The method for regenerating the deactivated black phosphorus catalyst according to claim 1, wherein: The iodine compound is selected from potassium iodide, sodium iodide, bismuth iodide, phosphorus iodide, tin tetraiodide, tin diiodide, iodine bromide.

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