Sulfur-doped carbon-based dehydrochlorination catalyst supported on copper oxide and its preparation method

Abstract

This invention provides a sulfur-doped carbon-based catalyst for removing PH3 supported on copper oxide and its preparation method. The method involves first pretreating activated carbon particles, primarily by washing, then immersing them in a 12-15 wt% copper nitrate solution for ultrasonic impregnation for 1.5-2.5 hours. After the impregnation time, the activated carbon is washed and dried to obtain copper nitrate-loaded activated carbon. This activated carbon is then mixed with elemental sulfur powder at a mass ratio of 1:(0.51-0.52) as a mixture. Finally, the mixture is calcined in a tube furnace to obtain the sulfur-doped carbon-based catalyst for removing PH3 supported on copper oxide. This preparation method, through specific process improvements in the heating method during calcination, exhibits superior catalytic performance, achieving a PH3 removal efficiency of over 200 mg / g with a removal efficiency of not less than 80%, significantly outperforming similar products described in existing literature.

Description

Technical Field

[0001] This invention belongs to the field of industrial exhaust gas dehydrogenation catalyst technology, and relates to a sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide and its preparation method. Background Technology

[0002] There are numerous enterprises producing yellow phosphorus in my country, with a total annual output exceeding 1 million tons. The tail gas produced during yellow phosphorus production contains 85%–95% carbon monoxide (CO), but also contains 750–1000 mg / m³ of phosphine (PH3) impurities. 3 The presence of pH3 not only reduces the purity of CO and increases the difficulty of CO purification, but also corrodes equipment and causes catalyst poisoning. Therefore, removing pH3 is of practical significance for the resource utilization of CO.

[0003] Currently, methods for removing PH3 are mainly divided into two categories: wet and dry methods. Wet methods can treat a larger total amount of pollutants and have high removal efficiency, but they also generate a larger volume of wastewater, which can easily lead to secondary pollution. Dry purification processes mainly use adsorption-catalytic oxidation, which has advantages such as simple operation, high purification efficiency, and regenerable catalysts, but it also has problems such as limited catalyst adsorption capacity and easy deactivation. Adsorption-catalytic oxidation uses a catalyst to oxidize PH3 into phosphorus pentoxide (P2O5), which is then removed. This is because P2O5 is more easily adsorbed by the catalyst than PH3. The reaction temperature for adsorption-catalytic oxidation is generally below 200℃, resulting in low energy consumption, fewer byproducts, and the avoidance of feed gas cracking under low-temperature conditions. Therefore, adsorption-catalytic oxidation is currently the main method for removing PH3.

[0004] In adsorption-catalytic oxidation, the mainstream approach that has been validated and is cost-effective for production use is the use of supported metal oxide catalysts. The inventors' preliminary project research revealed that using activated carbon supported with copper oxide is an ideal catalyst choice for PH3 removal. However, currently reported copper oxide-supported activated carbon PH3 removal catalysts generally suffer from the key drawbacks of low catalytic performance and small removal capacity (removal amount less than 100 mg / g).

[0005] Doping modification is a commonly used strategy to improve the oxidative removal of PH3 by activated carbon catalysts with copper oxide loading. In particular, doping modification using thiophene or thiophene derivatives as a sulfur source has been proven to significantly improve the catalytic performance of the catalyst. For example, Chinese invention patent "A sulfur-doped carbon material and its preparation method and application" (CN114105122B, China Petroleum & Chemical Corporation) discloses a technique for doping activated carbon using thiophene as a sulfur source.

[0006] While existing studies of this kind can indeed effectively improve the removal efficiency of catalysts, they generally suffer from drawbacks such as complex preparation processes and high production costs. Furthermore, thiophene or thiophene derivatives themselves possess a certain degree of toxicity, thus requiring stringent environmental conditions for production. Currently, they are mainly used in high-cost, high-value fields such as batteries. In addition, the inventors of this invention have discovered during their long-term research that most catalysts reported in the literature for removing PH3 require aerobic conditions to exhibit excellent performance; however, high oxygen content conditions in industrial exhaust gases can easily lead to risks such as explosions.

[0007] In summary, there is still a lack of practical and feasible methods suitable for industrial applications that can deeply remove PH3 under low-temperature and anaerobic conditions, and are simple, easy to operate, and highly operable. Summary of the Invention

[0008] To address the problems in the prior art, this invention provides a sulfur-doped carbon-based catalyst for removing PH3 supported on copper oxide and its preparation method. This preparation method, through specific improvements to the heating process in the calcination treatment, yields a novel copper oxide-supported sulfur-doped carbon-based catalyst with high PH3 removal efficiency. This catalyst can deeply remove PH3 gas under low-temperature, oxygen-free conditions, and achieves a PH3 removal efficiency of over 200 mg / g with a removal rate of not less than 80%, significantly outperforming similar products described in existing literature.

[0009] To achieve the above objectives, the present invention employs a technical solution consisting of the following technical measures.

[0010] This invention provides a method for preparing a sulfur-doped carbon-based catalyst for removing PH3 supported on copper oxide, mainly comprising the following steps:

[0011] (1) The activated carbon particles are pretreated mainly by washing and then used as pretreated activated carbon for later use.

[0012] (2) Immerse the pretreated activated carbon in step (1) in a copper nitrate solution with a mass concentration of 12-15 wt% and ultrasonically impregnate for 1.5-2.5 h; after the time is up, wash to remove the residual copper nitrate solution and dry to obtain copper nitrate-loaded activated carbon.

[0013] (3) The activated carbon loaded with copper nitrate obtained in step (2) and elemental sulfur powder are mixed at a mass ratio of 1:(0.51~0.52) to form a mixture;

[0014] The mixture was then calcined in a tube furnace under a high-purity argon atmosphere (purity ≥ 99.999%) to prepare a sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide.

[0015] The calcination process is performed according to the following heating sequence:

[0016] ① After heating to 28-32℃, maintain this temperature for 28-32 minutes;

[0017] ② Increase the temperature to 88–92℃ at a rate of 6–6.1℃ / min and hold at that temperature for 28–32 min;

[0018] ③ Increase the temperature to 148-152℃ at a rate of 3-3.1℃ / min, and then increase the temperature to 198-202℃ at a rate of 2-2.1℃ / min;

[0019] ④ Heat to 498-502℃ at a rate of 5-5.1℃ / min, maintain this temperature for 118-122 minutes, and then automatically cool down.

[0020] In this article, the activated carbon particles mentioned in step (1) are conventional commercially available activated carbon particles. It is advisable to use activated carbon particles of general specifications in this technical field (industrial tail gas de-PH3 catalyst), with a particle size of 4 to 10 mm.

[0021] In this document, the activated carbon particles described in step (1) are typically accompanied by residual impurities or other contaminants / stains, which can affect the catalytic performance of the catalyst subsequently prepared, especially commercially available activated carbon particles. Therefore, it is necessary to pretreat the activated carbon particles, primarily by washing. This pretreatment, primarily by washing, can be a pretreatment method known in the art, and those skilled in the art can perform the specific operation according to conventional production processes or methods described in the prior art.

[0022] In one of the technical solutions, in order to improve the pretreatment effect on activated carbon particles, step (1) mainly includes washing pretreatment, specifically: the activated carbon particles are washed with ultrapure water and dried, then washed with alkali, and then washed with ultrapure water and dried to obtain pretreated activated carbon.

[0023] In the above technical solution, alkaline washing can be further preferably carried out by immersion in an alkaline solution. The alkaline solution can be selected from conventional alkaline washing solutions such as sodium hydroxide solution or potassium hydroxide solution, and the mass concentration of the alkaline solution is preferably 5-7%. The immersion time is preferably 12-14 hours at room temperature and pressure.

[0024] It should be noted that the above technical solution mainly includes pretreatment for washing, the purpose of which is to remove residual impurities or other impurities / stains attached to the surface of activated carbon particles. The above preferred pretreatment process steps are mainly carried out under laboratory conditions. In actual industrial production, the pretreatment method can be improved and replaced according to actual conditions and common knowledge.

[0025] In this paper, the pretreated activated carbon described in step (2) is immersed in a copper nitrate solution with a mass concentration of 12-15 wt% and ultrasonically impregnated for 1.5-2.5 h. This is a conventional process for loading metal salts onto activated carbon. The amount of metal salt (copper nitrate) solution used is preferably 1-4 ml / g based on the mass of activated carbon.

[0026] In one of the technical solutions, the ultrasonic impregnation treatment in step (2) preferably uses ultrasonic impregnation treatment with an ultrasonic frequency of 20-30Hz and an ultrasonic temperature of 30-40℃.

[0027] In this article, the roasting process described in step (3), wherein the heating method ① is to raise the temperature to 28-32°C, since this temperature is close to the room temperature, any heating rate can be used, or the conventional automatic heating rate of the tube furnace can be used.

[0028] In this paper, the range values ​​of temperature, rate and time in heating methods ① to ④ in step (3) can be any value within the range as the actual parameter, or the range of error caused by instruments, personnel operation or other objective conditions within the range.

[0029] In this document, the mixing, washing, and drying processes all follow conventional principles in chemical processes, and those skilled in the art can perform the specific operations based on common knowledge.

[0030] In the above technical solutions, under laboratory conditions, washing is usually done with ultrapure water, and the washing is performed 3 or more times.

[0031] On the other hand, the sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide provided by the present invention is applied to the dehydrogenation of industrial tail gas, especially under anaerobic conditions, and at a reaction temperature of at least 50°C, to catalyze the removal of PH3.

[0032] The present invention has the following beneficial effects:

[0033] 1. The first inventive point of this invention is that, through specific process improvements to the heating method in the calcination process, the sulfur-doped carbon-based PH3 removal catalyst with copper oxide support prepared has excellent catalytic performance. Specifically, the catalyst can deeply remove PH3 gas under low temperature and oxygen-free conditions, and the PH3 removal amount reaches more than 200 mg / g with a removal efficiency of not less than 80%, which is significantly better than similar products described in existing literature in this field.

[0034] 2. The second inventive point of this invention is that, under the above-mentioned improved calcination conditions, activated carbon loaded with copper oxide is directly doped with elemental sulfur powder, and its product performance is significantly higher than that of the mainstream existing technology that uses non-elemental sulfur elements such as copper sulfate and copper sulfide for doping.

[0035] 3. The overall process of this invention is simple and easy to operate, and it can be directly applied to the current production process of PH3 removal catalysts. It has excellent practicality, low cost, and is easy to promote as an advantageous product in the market.

[0036] Instruction manual illustrations

[0037] Figure 1 This is a partial flowchart of the preparation method steps in Embodiment 1 of the present invention.

[0038] Figure 2 The images show the sulfur-doped carbon-based PH3 removal catalyst with copper oxide supported prepared in Example 1 of this invention, before the PH3 removal test (left image) and after the test (right image).

[0039] Figure 3 The graph shows the removal efficiency of the sulfur-doped carbon-based PH3 removal catalyst supported on copper oxide prepared in Example 1 of this invention during the PH3 removal test.

[0040] Figure 4 The images shown are of the sample in Comparative Example 1 of this invention, where the pretreated activated carbon was used directly as a catalyst, before the pH 3 removal test (left image) and after the test (right image).

[0041] Figure 5 This is a line graph showing the removal efficiency of the pretreated activated carbon sample used directly as a catalyst in the PH3 removal test in Comparative Example 1 of this invention.

[0042] Figure 6 The images shown are of the sulfur-doped carbon-based PH3 removal catalyst with copper sulfide loading prepared in Comparative Example 2 of this invention, before the PH3 removal test (left image) and after the test (right image).

[0043] Figure 7The graph shows the removal efficiency of the sulfur-doped carbon-based PH3 removal catalyst supported on copper sulfide prepared in Comparative Example 2 of this invention in the PH3 removal test.

[0044] Figure 8 The images shown are of the sulfur-doped carbon-based PH3 removal catalyst with copper oxide supported prepared in Comparative Example 3 of this invention, before the PH3 removal test (left image) and after the test (right image).

[0045] Figure 9 The graph shows the removal efficiency of the sulfur-doped carbon-based PH3 removal catalyst with copper oxide supported prepared in Comparative Example 3 of this invention in the PH3 removal test.

[0046] Figure 10 These are photographs of the scene during the PH3 removal test in Embodiment 1 and Comparative Examples 1-3 of the present invention. The instrument in the figure is a gas chromatograph GC9790Plus. Detailed Implementation

[0047] To further understand the present invention, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims. Those skilled in the art can refer to the content of this document to appropriately improve the process parameters. In particular, it should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention. Although it is believed that those skilled in the art will fully understand the following terms, the following definitions are set forth to help illustrate the subject matter disclosed in the present invention.

[0048] This invention provides a method for preparing a sulfur-doped carbon-based catalyst for removing PH3 supported on copper oxide, mainly comprising the following steps:

[0049] (1) The activated carbon particles are pretreated mainly by washing and then used as pretreated activated carbon for later use.

[0050] (2) Immerse the pretreated activated carbon in step (1) in a copper nitrate solution with a mass concentration of 12-15 wt% and ultrasonically impregnate for 1.5-2.5 h; after the time is up, wash to remove the residual copper nitrate solution and dry to obtain copper nitrate-loaded activated carbon.

[0051] (3) The activated carbon loaded with copper nitrate obtained in step (2) and elemental sulfur powder are mixed at a mass ratio of 1:(0.51~0.52) to form a mixture;

[0052] The mixture was then calcined in a tube furnace under a high-purity argon atmosphere (purity ≥ 99.999%) to prepare a sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide.

[0053] The calcination process is performed according to the following heating sequence:

[0054] ① After heating to 28-32℃, maintain this temperature for 28-32 minutes;

[0055] ② Increase the temperature to 88–92℃ at a rate of 6–6.1℃ / min and hold at that temperature for 28–32 min;

[0056] ③ Increase the temperature to 148-152℃ at a rate of 3-3.1℃ / min, and then increase the temperature to 198-202℃ at a rate of 2-2.1℃ / min;

[0057] ④ Heat to 498-502℃ at a rate of 5-5.1℃ / min, maintain this temperature for 118-122 minutes, and then automatically cool down.

[0058] In this document, the activated carbon particles mentioned in step (1) are conventional commercially available activated carbon particles, preferably those of the general specifications used in this technical field (industrial tail gas PH3 removal catalyst). In one embodiment, activated carbon particles with a particle size of 4–10 mm are selected.

[0059] In this document, the activated carbon particles described in step (1) are typically accompanied by residual impurities or other contaminants / stains, which can affect the catalytic performance of the catalyst subsequently prepared, especially commercially available activated carbon particles. Therefore, it is necessary to pretreat the activated carbon particles, primarily by washing. This pretreatment, primarily by washing, can be a pretreatment method known in the art, and those skilled in the art can perform the specific operation according to conventional production processes or methods described in the prior art.

[0060] In one embodiment, in order to improve the pretreatment effect on activated carbon particles, step (1) mainly includes washing pretreatment, specifically: the activated carbon particles are washed with ultrapure water and dried, then washed with alkali, and then washed with ultrapure water and dried to obtain pretreated activated carbon.

[0061] In one preferred embodiment, alkaline washing can be further preferably performed by immersion in an alkaline solution. The alkaline solution can be any solution commonly used in alkaline washing, such as sodium hydroxide solution or potassium hydroxide solution. The mass concentration of the alkaline solution is preferably 5-7%, for example, 5%, 5.5%, 6%, 6.5%, 7%, or any range or value between them. The immersion time is preferably 12-14 hours at room temperature and pressure, for example, 12 hours, 12.5 hours, 13 hours, 13.5 hours, 14 hours, or any range or value between them.

[0062] It should be noted that the above technical solution mainly includes pretreatment for washing, the purpose of which is to remove residual impurities or other impurities / stains attached to the surface of activated carbon particles. The above preferred pretreatment process steps are mainly carried out under laboratory conditions. In actual industrial production, the pretreatment method can be improved and replaced according to actual conditions and common knowledge.

[0063] In this document, the pretreated activated carbon described in step (2) is immersed in a copper nitrate solution with a mass concentration of 12-15 wt% and ultrasonically impregnated for 1.5-2.5 h, which is a conventional process for loading metal salts onto activated carbon. In one embodiment, the mass concentration of the copper nitrate solution is 12-15 wt%, for example, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, 15 wt%, or any range or value between them; the ultrasonic impregnation treatment is 1.5-2.5 h, for example, 1.5 h, 2 h, 2.5 h, or any range or value between them. In one embodiment, the amount of metal salt (copper nitrate) solution used, based on the mass of activated carbon, is preferably 1-4 ml / g, for example, 1 ml / g, 1.5 ml / g, 2 ml / g, 2.5 ml / g, 3 ml / g, 3.5 ml / g, 4 ml / g, or any range or value between them.

[0064] In one embodiment, the ultrasonic impregnation treatment in step (2) preferably uses ultrasonic frequencies of 20-30 Hz, such as 20 Hz, 21 Hz, 22 Hz, 23 Hz, 24 Hz, 25 Hz, 26 Hz, 27 Hz, 28 Hz, 29 Hz, 30 Hz or any range or point value between them; and ultrasonic impregnation treatment at ultrasonic temperatures of 30-40 ℃, such as 30 ℃, 31 ℃, 32 ℃, 33 ℃, 34 ℃, 35 ℃, 36 ℃, 37 ℃, 38 ℃, 39 ℃, 40 ℃ or any range or point value between them.

[0065] In this article, the roasting process described in step (3), wherein the heating method ① is to raise the temperature to 28-32°C, since this temperature is close to the room temperature, any heating rate can be used; in one embodiment, the conventional automatic heating rate of a tube furnace is used.

[0066] In this paper, the range values ​​of temperature, rate and time in heating methods ① to ④ in step (3) can be any value within the range as the actual parameter, or the range of error caused by instruments, personnel operation or other objective conditions within the range.

[0067] In this document, the mixing, washing, and drying processes all follow conventional principles in chemical processes, and those skilled in the art can perform the specific operations based on common knowledge.

[0068] In one embodiment, under laboratory conditions, washing is typically performed using ultrapure water, and the washing is repeated three times or more.

[0069] On the other hand, the sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide provided by the present invention is applied to the dehydrogenation of industrial tail gas, especially under anaerobic conditions, and at a reaction temperature of at least 50°C, to catalyze the removal of PH3.

[0070] The present application will be further explained in detail below with reference to embodiments. However, those skilled in the art should understand that these embodiments are provided for illustrative purposes only and are not intended to limit the present application.

[0071] Example

[0072] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all commercially available conventional products. This application should not be construed as being limited to the specific embodiments described.

[0073] 1. Raw materials

[0074] Material Name concentration Manufacturer <![CDATA[Cu(NO3)2·3H2O]]> 99.0％～102.0％ Chengdu Kelong Chemical Co., Ltd. NaOH 96％ Shanghai Aladdin Biochemical Technology Co., Ltd. <![CDATA[Na2S·9H2O]]> ≥98.0％ Chengdu Kelong Chemical Co., Ltd. <![CDATA[CuSO4]]> 99％ Chengdu Kelong Chemical Co., Ltd. <![CDATA[N2]]> ≥99.999％ Chengdu Xuyuan Chemical Co., Ltd. Ar ≥99.999％ Chengdu Xuyuan Chemical Co., Ltd. <![CDATA[PH3]]> 500ppm Chongqing Ruixin Gas Co., Ltd.

[0075] Example 1

[0076] The preparation method of the sulfur-doped carbon-based dehydrochlorination catalyst supported on copper oxide in this embodiment mainly includes the following steps:

[0077] (1) The activated carbon particles are pretreated mainly by washing and then used as pretreated activated carbon for later use.

[0078] The main process includes pretreatment with washing, specifically: the activated carbon particles are washed with ultrapure water and dried, then immersed in a 7% sodium hydroxide solution for 12 hours, and then washed with ultrapure water and dried to obtain the pretreated activated carbon.

[0079] (2) A copper nitrate solution with a mass concentration of 15% was prepared using copper nitrate trihydrate;

[0080] The pretreated activated carbon in step (1) was immersed in copper nitrate solution and ultrasonically impregnated for 2 hours. The amount of copper nitrate solution used was 4 ml / g based on the mass of the pretreated activated carbon. After the time was up, the activated carbon was washed to remove the residual copper nitrate solution and dried to obtain copper nitrate-loaded activated carbon.

[0081] (3) The activated carbon loaded with copper nitrate obtained in step (2) and elemental sulfur powder are mixed at a mass ratio of 1:0.52 to form a mixture;

[0082] The mixture was then calcined in a tube furnace under a high-purity argon atmosphere (purity ≥ 99.999%) to prepare a sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide, which was used as a catalyst sample.

[0083] The calcination process is performed according to the following heating sequence:

[0084] ① After heating to 30℃, maintain this temperature for 30 minutes;

[0085] ②Increase the temperature to 90℃ at a rate of 6℃ / min and hold at that temperature for 30min;

[0086] ③ Increase the temperature to 150℃ at a rate of 3℃ / min, and then increase it to 200℃ at a rate of 2℃ / min;

[0087] ④ Heat to 500℃ at a rate of 5℃ / min, maintain this temperature for 120 minutes, and then automatically cool down.

[0088] Weigh 3.0827g of the catalyst sample obtained in Example 1 and place it in... In the quartz reactor, the carrier gas used for the reaction was high-purity nitrogen (purity ≥99.999%), and the reaction conditions were: pH 3 concentration 207.51 mg / Nm³. 3 airspeed 2260 h -1 The reaction temperature is 70℃. For example... Figure 3 As shown, the removal efficiency of the catalyst sample for PH3 remained relatively stable at around 99% in the first 168 hours, and then began to fluctuate and decline until it dropped below 80% after 336 hours, with a removal amount of PH3 of 260.32 mg / g.

[0089] The results showed that the catalyst sample obtained in Example 1 had a significant effect on the removal of PH3. After reacting at 70℃ for 168 h, the removal efficiency of PH3 remained stable at over 99%. Even after the efficiency started to decline, it was still able to maintain a removal rate of over 80% of PH3 for a relatively long period of time, indicating that the catalyst has stable and good activity.

[0090] It should be noted that the above tests were conducted under anaerobic conditions, and the removal amount was significantly better than that of similar products described in existing literature in this field. It is speculated that the enhanced performance is mainly due to the improvement of the heating method of the roasting process and the use of elemental sulfur powder. The specific principle is currently unknown due to the limited research and development conditions.

[0091] Furthermore, the catalyst has a simple manufacturing process, low requirements for material shape, a wide range of applicable processes, and the activated carbon-based support is inexpensive and readily available, resulting in low overall economic cost. It is a practical and feasible method for purifying PH3 in industrial waste gas.

[0092] Comparative Example 1

[0093] The preparation method of this comparative carbon-based dehydrochlorination catalyst mainly includes the following steps:

[0094] The activated carbon granules are pretreated, mainly by washing, and then used as pretreated activated carbon for later use.

[0095] The main process includes pretreatment with washing, specifically: the activated carbon particles are washed with ultrapure water and dried, then immersed in a 7% sodium hydroxide solution for 12 hours, and then washed with ultrapure water and dried to obtain the pretreated activated carbon.

[0096] The pretreated activated carbon was used directly as a catalyst sample.

[0097] Weigh 3.1409 g of the catalyst sample obtained in Comparative Example 1 and place it into... In the quartz reactor, the carrier gas used for the reaction was high-purity nitrogen (purity ≥99.999%), and the reaction conditions were: pH 3 concentration 207.26 mg / Nm³. 3 airspeed 2260 h -1 The reaction temperature is 70℃. For example... Figure 5 As shown, the catalyst sample had a poor removal effect on PH3 gas. The removal efficiency of PH3 gas dropped to below 80% after 2 hours of reaction, and the amount of PH3 removed was 2.62 mg / g.

[0098] The results show that the catalyst sample obtained in Comparative Example 1 had a very small amount of PH3 removal under conditions of no copper oxide loading and no sulfur doping.

[0099] Comparative Example 2

[0100] The preparation method of the comparative copper sulfide-supported sulfur-doped carbon-based dehydrochlorination catalyst mainly includes the following steps:

[0101] (1) The activated carbon particles are pretreated mainly by washing and then used as pretreated activated carbon for later use.

[0102] The main process includes pretreatment with washing, specifically: the activated carbon particles are washed with ultrapure water and dried, then immersed in a 7% sodium hydroxide solution for 12 hours, and then washed with ultrapure water and dried to obtain the pretreated activated carbon.

[0103] (2) A copper nitrate solution with a mass concentration of 15% was prepared using copper nitrate trihydrate;

[0104] The pretreated activated carbon in step (1) was immersed in copper nitrate solution. The amount of copper nitrate solution used was 4 ml / g based on the mass of the pretreated activated carbon. Then sodium sulfide nonahydrate was added. The mass ratio of activated carbon to sodium sulfide nonahydrate was 1:3.5. After soaking together for 2 hours, the activated carbon was washed and dried to obtain activated carbon loaded with copper sulfide.

[0105] (3) The activated carbon loaded with copper sulfide obtained in step (2) is calcined in a tube furnace. The calcination process is carried out in a high-purity argon atmosphere (purity ≥99.999%) to prepare a sulfur-doped carbon-based de-PH3 catalyst loaded with copper sulfide, which is used as a catalyst sample.

[0106] The calcination process is performed according to the following heating sequence:

[0107] ① After heating to 30℃, maintain this temperature for 30 minutes;

[0108] ②Increase the temperature to 90℃ at a rate of 6℃ / min and hold at that temperature for 30min;

[0109] ③ Increase the temperature to 150℃ at a rate of 3℃ / min, and then increase it to 200℃ at a rate of 2℃ / min;

[0110] ④ Heat to 500℃ at a rate of 5℃ / min, maintain this temperature for 120 minutes, and then automatically cool down.

[0111] Weigh 3.0175g of the catalyst sample obtained in Comparative Example 2 and place it into... In the quartz reactor, the carrier gas used for the reaction was high-purity nitrogen (purity ≥99.999%), and the reaction conditions were: pH 3 concentration 214.42 mg / Nm³. 3 airspeed 2260 h -1 The reaction temperature is 70℃. For example... Figure 7As shown, the efficiency of the catalyst sample dropped below 80% after 7 hours of reaction, and its removal of PH3 was 6.40 mg / g.

[0112] The results show that the catalyst sample prepared by sulfur doping in Comparative Example 2 through a non-elemental sulfur method has significantly inferior performance compared to Example 1.

[0113] Comparative Example 3

[0114] The preparation method of the comparative copper oxide-supported sulfur-doped carbon-based dehydrochlorination catalyst mainly includes the following steps:

[0115] (1) The activated carbon particles are pretreated mainly by washing and then used as pretreated activated carbon for later use.

[0116] The main process includes pretreatment with washing, specifically: the activated carbon particles are washed with ultrapure water and dried, then immersed in a 7% sodium hydroxide solution for 12 hours, and then washed with ultrapure water and dried to obtain the pretreated activated carbon.

[0117] (2) A copper sulfate solution with a mass concentration of 15% was prepared using copper sulfate.

[0118] The pretreated activated carbon in step (1) was immersed in copper sulfate solution and ultrasonically impregnated for 2 hours. The amount of copper sulfate solution used was 4 ml / g based on the mass of the pretreated activated carbon. After the time was up, the activated carbon was washed to remove the residual copper sulfate solution and dried to obtain copper sulfate-loaded activated carbon.

[0119] (3) The activated carbon loaded with copper sulfate obtained in step (2) is calcined in a tube furnace. The calcination process is carried out in a high-purity argon atmosphere (purity ≥99.999%) to prepare a sulfur-doped carbon-based de-PH3 catalyst loaded with copper oxide, which is used as a catalyst sample.

[0120] The calcination process is performed according to the following heating sequence:

[0121] ① After heating to 30℃, maintain this temperature for 30 minutes;

[0122] ②Increase the temperature to 90℃ at a rate of 6℃ / min and hold at that temperature for 30min;

[0123] ③ Increase the temperature to 150℃ at a rate of 3℃ / min, and then increase it to 200℃ at a rate of 2℃ / min;

[0124] ④ Heat to 500℃ at a rate of 5℃ / min, maintain this temperature for 120 minutes, and then automatically cool down.

[0125] Weigh 3.0394 g of the catalyst sample obtained in Comparative Example 3 and place it into... In the quartz reactor, the carrier gas used for the reaction was high-purity nitrogen (purity ≥99.999%), and the reaction conditions were: pH 3 concentration 185.60 mg / Nm³. 3 airspeed 2260 h -1 The reaction temperature is 70℃. For example... Figure 9 As shown, the efficiency of the catalyst sample began to gradually decrease 145 h after the start of the reaction, and dropped below 80% after 216 h, with a removal amount of PH3 of 150.18 mg / g.

[0126] The results show that, although the heating method of calcination treatment was improved, the catalyst sample obtained in Comparative Example 3 has better PH3 removal performance compared with existing technical literature, but it is still significantly inferior to Example 1.

[0127] To further verify the PH3 removal performance of the catalyst samples from the above examples and comparative examples, 1.0 g of the deactivated catalyst samples from Example 1 and Comparative Example 1 (i.e., catalyst samples with a removal efficiency reduced to less than 80%) were taken and soaked in 20 mL of ultrapure water at 50 °C for 2 h. The catalyst samples were then removed as soaking solutions, and the phosphate ions (PO4) in the soaking solution were determined using an ICS-90 ion chromatograph. 3- The concentration of ) was determined, and the results are as follows:

[0128] Sample Name Comparative Example 1 Example 1 <![CDATA[PO4 3- Concentration (mg / L) 8.87 17500

[0129] Calculations of the above results show that the concentration of phosphate ions released by the deactivated catalyst sample in the soaking solution in Example 1, after conversion, indicates that its removal of PH3 is 333.33 mg / g, which is higher than the result calculated by integral calculation formula after GC9790Plus test (test method of Example 1 and Comparative Examples 1-3). This indicates that the catalyst sample obtained in Example 1 has a very good removal effect on PH3.

[0130] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a sulfur-doped carbon-based dehydrochlorination catalyst supported on copper oxide, characterized in that... Includes the following steps: (1) The activated carbon particles are pretreated, including washing, and then used as pretreated activated carbon for later use. (2) Immerse the pretreated activated carbon in step (1) in a copper nitrate solution with a mass concentration of 12~15wt% and ultrasonically impregnate for 1.5~2.5h; after the time is up, wash to remove the residual copper nitrate solution and dry to obtain copper nitrate loaded activated carbon. (3) The activated carbon loaded with copper nitrate obtained in step (2) and elemental sulfur powder are mixed at a mass ratio of 1:(0.51~0.52) to form a mixture; The mixture was then calcined in a tube furnace under a high-purity argon atmosphere with a purity of ≥99.999% to prepare a sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide. The calcination process is performed according to the following heating sequence: ① After heating to 28~32℃, maintain this temperature for 28~32 minutes; ② Increase the temperature to 88-92℃ at a rate of 6-6.1℃ / min and hold at that temperature for 28-32min; ③ Increase the temperature to 148-152℃ at a rate of 3-3.1℃ / min, and then increase the temperature to 198-202℃ at a rate of 2-2.1℃ / min; ④ Heat to 498-502℃ at a rate of 5-5.1℃ / min, maintain this temperature for 118-122 minutes, and then automatically cool down.

2. The preparation method according to claim 1, characterized in that: The pretreatment mentioned in step (1) includes washing, specifically: the activated carbon particles are washed with ultrapure water and dried, then washed with alkali, and then washed with ultrapure water and dried to obtain the pretreated activated carbon.

3. The preparation method according to claim 2, characterized in that: The alkaline washing is carried out by immersion in an alkaline solution; wherein the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution, and the mass concentration of the alkaline solution is 5~7%; the immersion is specifically carried out at room temperature and pressure for 12~14 hours.

4. The preparation method according to claim 1, characterized in that: The ultrasonic impregnation treatment in step (2) uses ultrasonic frequency of 20~30Hz and ultrasonic temperature of 30~40℃.

5. A sulfur-doped carbon-based dehydrocatalyst for removing PH3 supported on copper oxide prepared by the method described in claim 1.

6. The application of the sulfur-doped carbon-based dehydrogenation catalyst supported on copper oxide as described in claim 5 in the field of dehydrogenation of PH3 gas.

7. The application according to claim 6, characterized in that: The catalytic reaction removes PH3 under anaerobic conditions and at a reaction temperature of at least 50°C.

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