Preparation method and application of activated carbon loaded carbon black catalyst for improving dispersion process
By dispersing carbon black on the surface of activated carbon and combining it with ultrasound and stirring technology, the agglomeration problem of traditional activated carbon-loaded carbon black catalysts was solved, and a high-efficiency, low-cost catalyst was prepared, which is suitable for fields such as methane cracking and hydrogen production.
Patent Information
- Application Number
- CN202510812662.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-18
- Publication Date
- 2025-10-10
AI Technical Summary
Traditional activated carbon-loaded carbon black catalysts experience carbon black agglomeration in the methane cracking hydrogen production reaction, which leads to a reduction in the catalyst's specific surface area and active sites, affecting the catalytic performance. In addition, the preparation process is complex and environmentally unfriendly, making it difficult to apply on a large scale.
Dispersants such as CTAB, PVP, Tween 80 and PAA are used to assist in the dispersion of carbon black, and ultrasonic and stirring techniques are combined to improve the dispersion of carbon black on the activated carbon surface. The organic dispersant is removed by high-temperature calcination, and the binding force between carbon black and activated carbon is enhanced to prepare a catalyst with high catalytic activity and good thermal stability.
It significantly improves the dispersion and uniformity of the catalyst, increases the utilization rate of catalytic active sites, extends the service life of the catalyst, reduces the preparation cost, and is suitable for large-scale industrial applications.
Smart Images
Figure CN120754835A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of catalysts, and particularly relates to a preparation method of an activated carbon supported carbon black catalyst with improved dispersion process and application thereof. BACKGROUND
[0002] Methane is not only one of the main fossil fuels, but also a key component of global greenhouse gas emissions, and its greenhouse effect is much higher than that of carbon dioxide. With the growth of global energy demand and the intensification of climate change problems, developing efficient methane utilization technologies, especially clean energy utilization of methane such as hydrogen production, has become the focus of global attention.
[0003] Methane cracking for hydrogen production is a potential technical path that can obtain hydrogen without emitting carbon dioxide, however, the methane molecular structure is stable, and the high bond energy of C-H bond needs to be broken at high temperature, usually more than 1200℃. This high temperature requirement brings huge energy consumption, and in the cracking process, carbon deposition on the surface of the catalyst often occurs, leading to rapid deactivation of the catalyst. In addition, existing methane cracking catalysts mainly rely on metal catalysts (such as Ni, Co, Fe, etc.), although the performance of metal catalysts is good, but its high cost, scarce resources and thermal stability problems at high temperature seriously limit its promotion in large-scale industrial applications.
[0004] In recent years, carbon-based catalysts (such as activated carbon, carbon black, mesoporous carbon) have gradually attracted attention due to their low cost, good thermal stability, large specific surface area and rich pore structure. In particular, activated carbon supported carbon black catalysts show certain activity and stability in the reaction of methane cracking for hydrogen production, and have become one of the alternative choices of metal catalysts. However, in the traditional preparation method of activated carbon supported carbon black catalyst, the dispersibility of carbon black on the surface of activated carbon is poor, and agglomeration easily occurs, leading to insufficient exposure of active sites, reduction of specific surface area, and thus affecting the catalytic performance. In addition, the preparation process is complex and not environmentally friendly, which limits the further application and promotion of carbon-based catalysts. SUMMARY
[0005] In order to overcome some of the problems mentioned in the background above, the application provides a preparation method of an activated carbon supported carbon black catalyst with improved dispersion process and application thereof, to at least partially solve the above problems.
[0006] According to the technical scheme of the application, a preparation method of an activated carbon supported carbon black catalyst with improved dispersion process is provided, which comprises the following steps:
[0007] adding a dispersant into deionized water, fully dissolving and stirring uniformly to obtain a dispersion liquid;
[0008] The nanometer conductive carbon black is added into the dispersion liquid and stirred to obtain a carbon black dispersion liquid;
[0009] After the activated carbon is cleaned and dried, the carbon black dispersion liquid is added for ultrasonic treatment and stirring to make the carbon black fully loaded on the surface of the activated carbon, and then negative pressure filtration is performed to filter out the solid part for drying to obtain a pretreated catalyst.
[0010] The pretreated catalyst is placed in a tube furnace in a nitrogen atmosphere for high-temperature calcination.
[0011] Further, the dispersant is added into deionized water for ultrasonic treatment at a frequency of 40 kHz for 30 min, and then magnetic stirring is performed at a speed of 600 r / min at 50°C for 1 h.
[0012] Further, the nanometer conductive carbon black is added into the dispersion liquid for ultrasonic treatment at a frequency of 40 kHz for 30 min, and then stirring is performed at a speed of 600 r / min at 50°C for 2 h.
[0013] The nanometer conductive carbon black is added into the dispersion liquid for ultrasonic treatment at a frequency of 40 kHz for 30 min, and then stirring is performed at a speed of 600 r / min at 50°C for 2 h.
[0014] Further, 8 g of the activated carbon is cleaned and dried, and then added into 200-203 ml of the carbon black dispersion liquid for ultrasonic treatment at a frequency of 40 kHz for 30 min, and then stirring is performed at a speed of 600 r / min at 50°C for 1 h.
[0015] Further, the temperature in the tube furnace during the high-temperature calcination is 920-980°C, and the calcination time is 1-4 h.
[0016] Further, the dispersant includes one or more of cetyltrimethylammonium bromide, polyvinylpyrrolidone, Tween 80, sodium polyacrylate, sodium dodecyl sulfate, polyethylene glycol, and polyacrylamide.
[0017] Further, when the dispersant is a solid, the addition amount of the dispersant in the deionized water is 0.8-1.2 g / 200 ml, and when the dispersant is a liquid, the addition amount of the dispersant in the deionized water is 0.8-1 ml / 200 ml.
[0018] Further, the particle size of the activated carbon is 20-50 mesh.
[0019] The activated carbon is cleaned by deionized water until the deionized water solution is clear, and then the activated carbon is filtered and placed in a drying oven for drying at 100-110°C for 5-8 h.
[0020] In another aspect, the application also provides an activated carbon loaded carbon black catalyst with improved dispersion process, which is prepared according to the above preparation method.
[0021] On the other hand, the present invention also provides an application of an activated carbon-supported carbon black catalyst with an improved dispersion process. The activated carbon-supported carbon black catalyst prepared according to the above preparation method is used in the fields of methane cracking to produce hydrogen, synthesis gas generation, carbon dioxide reduction and selective oxidation of hydrocarbon gases.
[0022] Compared with the prior art, the present invention has the following beneficial effects:
[0023] The present invention removes the organic dispersant by calcining at high temperature, further stabilizing the distribution of carbon black particles on the surface of the activated carbon, so that the prepared catalyst has good thermal stability and can maintain high catalytic activity in the process of methane cracking and hydrogen production;
[0024] The present invention effectively improves the dispersion of carbon black on the surface of activated carbon by using different dispersants and a method combining ultrasound and magnetic stirring, prevents carbon black agglomeration, and improves the uniformity of the catalyst and the utilization rate of active sites. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is a process flow chart of an embodiment of the present invention;
[0026] Figure 2 is a graph showing particle size in carbon black dispersions under different conditions in an embodiment of the present invention;
[0027] Figure 3 Surface micromorphology of catalysts prepared under different conditions in the embodiments of the present invention;
[0028] Figure 4 is a graph showing methane conversion rates catalyzed by different materials according to an embodiment of the present invention;
[0029] Figure 5 This is a graph showing the effect of different carbon black loadings on the conversion rate of catalytic methane cracking reaction in an embodiment of the present invention. DETAILED DESCRIPTION
[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection.
[0031] Methane molecules have a stable tetrahedral structure, and the C-H bonds within methane have high bond energies. Traditional methane cracking technology for hydrogen production requires temperatures exceeding 1200°C to break the C-H bonds, making the reaction extremely energy-intensive. Furthermore, high-temperature cracking often results in significant carbon deposition, leading to catalyst deactivation and reduced reaction efficiency. Therefore, achieving efficient methane cracking to produce hydrogen at lower temperatures has become a key challenge in this field.
[0032] Currently, most catalysts used in methane cracking to produce hydrogen are metal catalysts (such as Ni, Co, and Fe). While these metal catalysts exhibit excellent catalytic performance, they are expensive and resource-scarce, hindering their industrialization. Furthermore, metal catalysts are prone to sintering at high temperatures, leading to loss or aggregation of active components and catalyst deactivation, further increasing operating costs.
[0033] Conventional activated carbon-supported carbon black catalysts suffer from carbon black agglomeration in methane cracking hydrogen production reactions. This results in uneven distribution of carbon black particles on the activated carbon surface, reducing the catalyst's specific surface area and active sites. Furthermore, the weak bonding between the carbon black and the support in conventional preparation processes causes carbon black particles to easily fall off during the reaction, compromising the catalyst's long-term stability. Poorly dispersed carbon black particles fail to fully expose active sites, impacting the efficiency of the methane cracking reaction. Furthermore, existing processes are complex, energy-intensive, and costly, making them difficult to implement on a large scale.
[0034] The purpose of the present invention is to address the above problems and to provide a method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process. By selecting a suitable dispersant (such as CTAB, PVP, Tween 80, and PAA), this method effectively improves the dispersibility of carbon black on the activated carbon surface, avoids carbon black agglomeration, increases the specific surface area and active site utilization of the catalyst, and significantly enhances the catalytic performance of the catalyst. Furthermore, the preparation method utilizes a process combining ultrasound and stirring to enhance the bonding between the activated carbon and the carbon black, ensuring the long-term stability of the catalyst. Furthermore, the preparation process of the present invention is simple, low-cost, and has good prospects for industrial application.
[0035] In the figures and specific examples, AC is activated carbon, BC is carbon black, CTAB is cetyltrimethylammonium bromide, PVP is polyvinylpyrrolidone, Tween 80 is Tween 80, PAA is sodium polyacrylate, SDS is sodium dodecyl sulfate, and PEG is polyethylene glycol.
[0036] The present invention provides a method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process, comprising the following steps:
[0037] Add the dispersant into deionized water, fully dissolve it and stir it evenly to obtain a dispersion;
[0038] Adding nano-conductive carbon black into the dispersion and stirring evenly to obtain a carbon black dispersion;
[0039] The activated carbon is washed and dried, and then added to the carbon black dispersion for ultrasonic treatment and stirring to allow the carbon black to be fully loaded on the surface of the activated carbon. The solid portion is then filtered out under negative pressure and dried to obtain a pretreated catalyst;
[0040] The pretreated catalyst was placed in a tubular furnace under a nitrogen atmosphere for high-temperature calcination.
[0041] In a further embodiment of this example, the dispersant is added to deionized water and ultrasonically treated at a frequency of 40 kHz for 30 minutes, and then magnetically stirred at a speed of 600 r / min at 50° C. for 1 hour.
[0042] In a further embodiment of this example, the nano-conductive carbon black is added to the dispersion and then ultrasonically treated at a frequency of 40 kHz for 30 min, and then stirred at a speed of 600 r / min at 50° C. for 2 h;
[0043] The amount of the nano-conductive carbon black added to the dispersion is 0.5-2 g / 200 ml.
[0044] In a further embodiment of this example, 8 g of the activated carbon was washed and dried, added to 200-203 ml of carbon black dispersion, and ultrasonically treated at a frequency of 40 kHz for 30 min, and then stirred at 50° C. and a speed of 600 r / min for 1 h.
[0045] In a further embodiment of this example, the temperature in the tube furnace during the high-temperature calcination process is 920-980° C., and the calcination time is 1-4 hours.
[0046] In a further embodiment of this example, the dispersant includes one or more of cetyltrimethylammonium bromide, polyvinyl pyrrolidone, Tween 80, sodium polyacrylate, sodium lauryl sulfate, polyethylene glycol and polyacrylamide.
[0047] In a further embodiment of this example, the dispersant is configured such that when the dispersant is solid, the amount added to deionized water is 0.8-1.2 g / 200 ml; when the dispersant is liquid, the amount added to deionized water is 0.8-1 ml / 200 ml.
[0048] In a further embodiment of this embodiment, the particle size of the activated carbon is 20-50 mesh;
[0049] The activated carbon is washed with deionized water for multiple times until the deionized water solution is clarified, and then the activated carbon is filtered and placed in a drying oven at 100-110° C. to dry for 5-8 hours.
[0050] It should be noted that the present invention uses dispersants (such as CTAB, PVP, Tween 80 and PAA) to assist in the dispersion of carbon black, and combines ultrasonic treatment and stirring technology. Compared with conventional loading methods, the dispersant-assisted technology significantly improves the dispersion of carbon black on the activated carbon surface. Ultrasound enhances the mass and heat transfer between carbon black and the carrier, ensures uniform loading of carbon black particles, reduces agglomeration, and thus significantly improves the overall catalytic performance of the catalyst.
[0051] Using activated carbon as a catalyst carrier, combined with the high surface area and electrical conductivity of carbon black, a supported catalyst with high catalytic activity and good thermal stability was prepared. Compared with traditional metal catalysts, activated carbon-supported carbon black catalysts are low-cost, abundant in resources, and suitable for large-scale production. Furthermore, the process employed is simple and energy-efficient, significantly shortening the preparation cycle and showing potential for industrialization.
[0052] The dispersant and preparation process parameters used in this invention are highly adjustable and can be optimized according to different reaction requirements and conditions, thereby achieving precise control of carbon black loading, dispersion, and catalytic active sites. This flexible control capability further ensures the catalyst's high performance under different processes and reaction conditions.
[0053] This method uses different types of dispersants (such as CTAB, PVP, Tween 80, and PAA) to assist in the preparation of activated carbon-supported carbon black catalysts. Combined with ultrasound and stirring techniques, this significantly improves the dispersion and uniformity of the carbon black on the activated carbon surface, effectively preventing carbon black agglomeration and enhancing the overall catalytic effect. The entire preparation process is simple and efficient, with a short preparation cycle and low cost, making it suitable for large-scale production and industrial applications.
[0054] The carrier material used in the method of the present invention is not limited to a certain type of activated carbon, and other porous carbon materials such as coconut shell activated carbon, carbon nanotubes, carbon fibers and mesoporous carbon can be used;
[0055] The activated carbon-supported carbon black catalyst prepared by the present invention is not only suitable for methane cracking to produce hydrogen, but can also be used for the cracking, conversion and catalytic reactions of other gases, such as synthesis gas generation, carbon dioxide reduction, selective oxidation of hydrocarbon gases, etc., providing the catalyst with a wide range of use value in various application scenarios.
[0056] On the other hand, an embodiment of the present invention further provides an activated carbon-supported carbon black catalyst with an improved dispersion process, which is an activated carbon-supported carbon black catalyst prepared according to the above preparation method.
[0057] On the other hand, an embodiment of the present invention also provides an application of an activated carbon-loaded carbon black catalyst with an improved dispersion process. The activated carbon-loaded carbon black catalyst prepared according to the above preparation method is used in the fields of methane cracking to produce hydrogen, synthesis gas generation, carbon dioxide reduction and selective oxidation of hydrocarbon gases.
[0058] Example 1
[0059] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0060] The cleaned activated carbon was placed in an oven at 105°C and dried for 3 hours to ensure complete removal of free moisture. Secondly, 1 g of polyvinyl pyrrolidone (PVP) dispersant was weighed and added to a beaker containing 200 ml of deionized water. The mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0061] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 1.0 g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8 g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0062] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0063] Example 2
[0064] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0065] The washed activated carbon was dried in an oven at 105°C for 3 hours to ensure complete removal of free moisture; secondly, 1 g of sodium polyacrylate (PAA) dispersant was weighed into a beaker containing 200 ml of deionized water, and the mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0066] The beaker was then placed on a magnetic stirrer and stirred at a temperature of 50°C and a speed of 600 r / min for 1 hour to ensure that the dispersant was fully dissolved and formed a stable and uniform dispersion; then, 1.0 g of carbon black was weighed into the dispersant solution and ultrasonically treated in an ultrasonic cleaner for 1 hour to initially disperse the carbon black particles. Subsequently, the mixture was continuously stirred at 50°C and 600 r / min for 2 hours to ensure uniform dispersion of the carbon black in the solution and prevent agglomeration; then, 8 g of the pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure uniform loading of the carbon black on the surface of the activated carbon.
[0067] After the impregnation was completed, the solid catalyst was recovered by filtration using a negative pressure filtration device. Subsequently, the solid catalyst was placed in an oven at 105°C and dried to constant weight (8 hours) to completely remove residual moisture and obtain the dried catalyst material; finally, the dried catalyst material was placed in a tube furnace and heated at a rate of 10°C / min from room temperature to 300°C under a nitrogen protective atmosphere, and then heated at a rate of 15°C / min to 950°C, and calcined at this temperature for 2 hours. After the end of the calcination, nitrogen was continued to be introduced and the quartz tube reactor was allowed to cool to room temperature to obtain the activated carbon-supported carbon black catalyst.
[0068] Example 3
[0069] First, 8 g of activated carbon raw material with a particle size of 20-50 mesh was repeatedly washed with deionized water until the filtrate was clear, about 3-5 times, to remove ash and surface impurities.
[0070] The washed activated carbon was dried in an oven at 105°C for 3 hours to ensure complete removal of free moisture; secondly, 1 ml of Tween 80 dispersant was weighed into a beaker containing 200 ml of deionized water, and the mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0071] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 1.0 g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8 g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0072] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0073] Example 4
[0074] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0075] The cleaned activated carbon was placed in an oven at 105°C and dried for 3 hours to ensure complete removal of free moisture. Secondly, 1 g of hexadecyltrimethylammonium bromide (CTAB) dispersant was weighed and added to a beaker containing 200 ml of deionized water. The mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0076] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 1.0 g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8 g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0077] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0078] Example 5
[0079] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0080] The cleaned activated carbon was placed in an oven at 105°C and dried for 3 hours to ensure complete removal of free moisture. Secondly, 1 g of polyvinyl pyrrolidone (PVP) dispersant was weighed and added to a beaker containing 200 ml of deionized water. The mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0081] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 0.5g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0082] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0083] Example 6
[0084] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0085] The cleaned activated carbon was placed in an oven at 105°C and dried for 3 hours to ensure complete removal of free moisture. Secondly, 1 g of polyvinyl pyrrolidone (PVP) dispersant was weighed and added to a beaker containing 200 ml of deionized water. The mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0086] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 1.5 g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8 g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0087] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0088] Example 7
[0089] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0090] The cleaned activated carbon was placed in an oven at 105°C and dried for 3 hours to ensure complete removal of free moisture. Secondly, 1 g of polyvinyl pyrrolidone (PVP) dispersant was weighed and added to a beaker containing 200 ml of deionized water. The mixed solution was ultrasonically treated in an ultrasonic cleaner for 30 minutes at an ultrasonic frequency of 40 kHz.
[0091] The beaker was then placed on a magnetic stirrer and stirred at 50°C and 600 rpm for 1 hour to ensure the dispersant was fully dissolved and a stable, uniform dispersion was formed. Next, 2.0 g of carbon black was weighed and added to the dispersant solution. Ultrasonic cleaning was performed using an ultrasonic cleaner for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure the carbon black was evenly dispersed in the solution and to prevent agglomeration. Next, 8 g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure the carbon black was evenly loaded on the surface of the activated carbon.
[0092] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0093] Comparative Example
[0094] First, take 8g of activated carbon raw material with a particle size of 20-50 mesh and repeatedly rinse it with deionized water until the filtrate is clear, about 3-5 times, to remove ash and surface impurities.
[0095] The cleaned activated carbon was dried in an oven at 105°C for 3 hours to ensure complete removal of free water. 1.0g of carbon black was added to deionized water and ultrasonically treated for 1 hour to initially break up the carbon black particles. The mixture was then magnetically stirred at 50°C and 600 rpm for 2 hours to ensure uniform dispersion of the carbon black and prevent agglomeration. Next, 8g of pretreated activated carbon was added to the carbon black dispersion and stirred at 50°C for 1 hour to ensure uniform carbon black loading on the activated carbon surface.
[0096] After the impregnation is completed, the solid catalyst is filtered using a negative pressure filtration device to recover the solid catalyst. The solid catalyst is then placed in a 105°C oven to dry to constant weight (8 hours) to completely remove residual moisture and obtain a dried catalyst material; finally, the dried catalyst material is placed in a tubular furnace and, under a nitrogen atmosphere, heated from room temperature to 300°C at a rate of 10°C / min, and then further heated to 950°C at a rate of 15°C / min. It is calcined at this temperature for 2 hours, and then nitrogen is continued to be introduced and the quartz tube reactor is cooled to room temperature to obtain an activated carbon-supported carbon black catalyst.
[0097] Attachment Figure 2 A comparative analysis of the particle size distribution of carbon black dispersions prepared with and without a dispersant was conducted. Without the addition of a dispersant, the carbon black particles were larger, with an average size exceeding 280 nm, indicating significant agglomeration. However, with the addition of a dispersant, the average particle size of the carbon black particles decreased significantly, and agglomeration was significantly reduced. This indicates that the addition of a dispersant effectively improves the dispersion of the carbon black, contributing to higher loading uniformity and catalytic activity in the subsequently prepared catalyst.
[0098] Attachment Figure 3 The microstructures of activated carbon supported carbon black catalyst materials prepared with and without dispersants were compared. Figure 3 As shown in Figure a, in the absence of a dispersant, nano carbon black is distributed in aggregate on the surface of activated carbon. This is because the particles are very small and the surface energy of the particles is very large. The tiny carbon black particles are easily combined together due to the interaction force, resulting in agglomeration between the particles and forming a larger secondary particle size. Dispersants are added during the preparation of carbon black dispersions so that they are adsorbed on the carbon black surface, changing the charge or physical environment of the particles and effectively inhibiting the agglomeration caused by van der Waals forces. Figure 3 As shown in (be), the carbon black is evenly distributed on the activated carbon surface without agglomeration. This indicates that the dispersant improves the uniformity of the carbon black distribution on the catalyst surface, thereby enhancing the activity and stability of the catalyst material.
[0099] The catalytic activity of different materials in catalyzing methane cracking to produce hydrogen was tested using a fixed-bed reactor. First, 2g of the prepared catalyst was weighed and fixed in the middle of a quartz tube reactor with quartz wool. 40ml / min of nitrogen was introduced to remove the air in the reactor to prevent oxidation of the catalyst material. At the same time, a programmed temperature device was used to increase the reactor temperature from room temperature to 950°C at a rate of 15°C / min. After reaching the reaction temperature and stabilizing, the nitrogen was converted into 20ml / min of CH4 and kept at this temperature for 2h. The post-reaction gas was then detected using a flue gas analyzer (MRU Nova plus) and recorded in real time using online software. Finally, after the reaction was completed, the reactor was cooled to room temperature under the protection of nitrogen. This example verified the catalytic activity and stability of different catalyst materials through the methane catalytic cracking hydrogen production experiment, as shown in the attached figure. Figure 4The study found that activated carbon-supported carbon black can significantly improve the methane conversion rate. When activated carbon is used as the catalyst material, the methane conversion rate drops sharply. The time for the methane conversion rate to drop to 50% is 42 minutes and it drops to 26.76% after 2 hours. The time for the activated carbon-supported carbon black catalyst prepared without dispersant to drop to 50% is 48 minutes, and the methane conversion rate is 29.71% after 2 hours. Further experiments compared the changing trend of the methane conversion rate of activated carbon-supported carbon black catalyst under different dispersant conditions. The time for the methane conversion rate of catalyst materials prepared with Tween80, PAA, CTAB and PVP as dispersants to drop to 50% is 56 minutes, 60 minutes, 61 minutes and 69 minutes, respectively. The methane conversion rates after 2 hours are 31.23%, 32.85%, 34.82% and 36.90%, respectively. That is, the introduction of the dispersant greatly delays the deactivation time of the catalyst and improves its catalytic activity. This will help develop more efficient and sustainable hydrogen production technologies and advance the field of clean energy research.
[0100] Example 1, Example 5, Example 6 and Example 7 respectively tested the effects of different carbon black loadings on the catalytic methane cracking reaction under the conditions of PVP as a dispersant. Figure 5 The study found that methane conversion increased with increasing carbon black loading in the initial reaction phase. The catalyst materials with carbon black loadings ranging from 0.5g to 2.0g achieved methane conversions of 89.6547%, 93.2165%, 100%, and 100%, respectively. However, the catalyst materials with high carbon black loadings deactivated more rapidly during the reaction, with methane conversions dropping to 50.683%, 51.96078%, 49.1972%, and 46.3456%, respectively, after 60 minutes. A carbon black loading of 1g exhibited excellent catalytic activity and stability, contributing to the methane cracking hydrogen production reaction.
[0101] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.
Claims
1. A method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process, characterized in that: The following steps are involved: Add the dispersant into deionized water, fully dissolve it and stir it evenly to obtain a dispersion; Adding nano-conductive carbon black into the dispersion and stirring evenly to obtain a carbon black dispersion; The activated carbon is washed and dried, and then added to the carbon black dispersion for ultrasonic treatment and stirring to allow the carbon black to be fully loaded on the surface of the activated carbon. The solid portion is then filtered out under negative pressure and dried to obtain a pretreated catalyst; The pretreated catalyst was placed in a tubular furnace under a nitrogen atmosphere for high-temperature calcination.
2. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: The dispersant was added to deionized water and ultrasonically treated at a frequency of 40 kHz for 30 minutes, and then magnetically stirred at a speed of 600 r / min at 50° C. for 1 hour.
3. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: After the nano-conductive carbon black is added to the dispersion, ultrasonic treatment is performed at a frequency of 40 kHz for 30 minutes, and then stirring is performed at a speed of 600 r / min at 50° C. for 2 hours; The amount of the nano-conductive carbon black added to the dispersion is 0.5-2 g / 200 ml.
4. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: 8 g of the activated carbon was washed and dried, added to 200-203 ml of carbon black dispersion, and ultrasonically treated at a frequency of 40 kHz for 30 min, and then stirred at 50° C. and a rotation speed of 600 r / min for 1 h.
5. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: During the high-temperature calcination process, the temperature in the tubular furnace is 920-980° C., and the calcination time is 1-4 hours.
6. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: The dispersant includes one or more of cetyltrimethylammonium bromide, polyvinyl pyrrolidone, Tween 80, sodium polyacrylate, sodium lauryl sulfate, polyethylene glycol and polyacrylamide.
7. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: The dispersant is configured such that when the dispersant is solid, the added amount in deionized water is 0.8-1.2 g / 200 ml; when the dispersant is liquid, the added amount in deionized water is 0.8-1 ml / 200 ml.
8. The method for preparing an activated carbon-supported carbon black catalyst with an improved dispersion process according to claim 1, characterized in that: The particle size of the activated carbon is 20-50 mesh; The activated carbon is washed with deionized water for multiple times until the deionized water solution is clarified, and then the activated carbon is filtered and placed in a drying oven at 100-110° C. to dry for 5-8 hours.
9. An activated carbon-supported carbon black catalyst with improved dispersion process, characterized in that: An activated carbon-supported carbon black catalyst prepared according to any one of claims 1 to 8.
10. An application of an activated carbon-supported carbon black catalyst for improving dispersion process, characterized in that: Application of the activated carbon-supported carbon black catalyst prepared according to any one of claims 1 to 8 in the fields of methane cracking to produce hydrogen, synthesis gas generation, carbon dioxide reduction and selective oxidation of hydrocarbon gases.