A porous ceramic carrier in-situ loaded catalyst and a preparation method thereof

Abstract

The application provides a porous ceramic carrier in-situ loaded catalyst and a preparation method thereof, and comprises the following steps: uniformly mixing ceramic raw materials, auxiliary materials and deionized water to form ceramic slurry; the auxiliary materials are used to make the ceramic slurry have rheological properties so as to keep the structure stable during impregnation and slurry discharge; impregnating a porous organic template in a catalyst precursor suspension for 5-15 min, so that the catalyst precursor is loaded on the inner pore surface of the porous organic template to obtain a first intermediate template; taking out the first intermediate template and impregnating it in the ceramic slurry for 5-20 min, taking out and discharging slurry to obtain a second intermediate template covered with a ceramic embryo; spraying catalyst precursor powder on the surface of the second intermediate template to obtain a third intermediate template, wherein the spraying amount of the catalyst precursor powder is 2.5-5.0% of the mass of the second intermediate template; and sintering the third intermediate template at 200-800 DEG C to obtain a porous ceramic carrier in-situ loaded catalyst.

Description

Technical Field

[0001] This invention belongs to the field of high-value utilization of solid waste, specifically to the field of catalysis technology, and relates to an in-situ supported catalyst on a porous ceramic support and its preparation method. Background Technology

[0002] The resource utilization of carbon dioxide, especially its conversion into high-value-added chemicals and fuels through catalytic hydrogenation, is considered one of the effective ways to achieve carbon cycling and mitigate the greenhouse effect. Among these methods, the carbon dioxide hydrogenation to methanol reaction has become a research hotspot in the field of carbon capture and utilization due to its high atom economy and the widespread application of methanol as a basic chemical feedstock and clean fuel.

[0003] The activation energy required for the production of methanol from carbon dioxide and hydrogen is very high, making it difficult to carry out under normal conditions. A catalyst is needed to provide specific active sites so that carbon dioxide and hydrogen can be chemically adsorbed, thereby lowering the energy barrier of the reaction and allowing it to proceed at lower temperatures and pressures. Such catalysts are generally Cu-based, Ni-based, Zn-based, etc.

[0004] The mechanism of the aforementioned catalyst supports involves loading the catalyst onto the support surface in a highly dispersed manner, increasing the specific surface area for contact with reactants and enhancing the number of active sites exposed to the reaction environment. Currently, the mainstream forms of catalyst supports include particulate supports and monolithic supports. Particulate supports involve forming the catalyst into spherical particles of a specific size, while monolithic supports involve loading the active catalyst components onto a monolithic support with a specific shape and structure using methods such as impregnation.

[0005] In industrial production processes, fixed-bed reactors with granular carriers are typically chosen due to their mature catalyst preparation process, flexible loading, and suitability for existing chemical plants. While granular carriers offer low raw material costs, they still suffer from low heat transfer efficiency, poor thermal conductivity of the granular bed, and high resistance, which can lead to increased side reactions, higher energy consumption, and catalyst deactivation. In contrast, monolithic catalysts offer higher mass transfer efficiency, enabling rapid diffusion of reactants and products within the reactor. They also allow for timely removal or supply of heat, effectively controlling reaction temperature. Furthermore, monolithic catalysts possess advantages such as high mechanical strength, the ability to withstand high pressure and gas flow impacts, and good chemical stability.

[0006] To obtain more reaction sites, most monolithic catalyst supports are porous structures. Typically, porous supports such as Al2O3, SiO2, ZrO2, and molecular sieves are prepared in advance, and then the active components are loaded onto the surface of the support by impregnation or other methods. Finally, the finished catalyst is obtained by drying and calcination.

[0007] However, during the impregnation process, due to capillary action and solute migration during drying, the active components tend to accumulate at the pore openings of the support, making it difficult to achieve uniform distribution on the inner wall of the pores, resulting in low utilization of active sites. The binding force between the active components formed by physical or chemical adsorption and the support is limited. Under the influence of the reaction stream and the thermal effect during the reaction process, the active components are prone to migration, aggregation, or even detachment, affecting the stability of the catalyst. When the concentration of the active component precursor in the impregnation solution is high, it is easy to deposit at the micropore inlet of the support, blocking part of the pores, reducing the effective specific surface area and diffusion efficiency, and increasing the mass transfer resistance.

[0008] In addition, existing catalyst preparation technologies typically employ a two-step process: first, a porous support is prepared, and then the catalyst is mounted on the porous support. If porous ceramics are used as the catalyst support, sintering at high temperatures, such as above 1000°C, is required, followed by loading the catalyst active material onto the support using methods such as impregnation. This preparation method is cumbersome, requires stringent process conditions, and suffers from the technical problems associated with the impregnation method, resulting in catalyst performance that fails to meet industry expectations and leaving significant room for improvement.

[0009] In view of this, the development of an in-situ supported catalyst on a porous ceramic support and its preparation method is of great industrial application value and technical significance. Summary of the Invention

[0010] The purpose of this invention is to solve the technical problems of uneven distribution of active components, weak bonding force with the support, and complex preparation methods when using porous ceramic supports to support catalysts in the prior art. Specifically, this invention provides an in-situ supported catalyst on a porous ceramic support and its preparation method.

[0011] To achieve the above objectives, the present invention proposes the following technical solution:

[0012] Firstly, a method for preparing an in-situ supported catalyst on a porous ceramic support is proposed, comprising:

[0013] Ceramic raw materials, auxiliary materials, and deionized water are uniformly mixed to form a ceramic slurry; the auxiliary materials are used to give the ceramic slurry rheological properties so as to maintain structural stability during impregnation and slurry discharge.

[0014] The porous organic template is immersed in the catalyst precursor suspension for 5-15 minutes, so that the catalyst precursor is loaded on the internal pore surface of the porous organic template to obtain the first intermediate template.

[0015] The first intermediate template is taken out and immersed in the ceramic slurry for 5-20 minutes. It is then removed and the slurry is drained to obtain the second intermediate template covered with the ceramic body.

[0016] Catalyst precursor powder is sprayed onto the surface of the second intermediate template to obtain a third intermediate template, wherein the amount of catalyst precursor powder sprayed is 2.5~5.0% of the mass of the second intermediate template;

[0017] The third intermediate template is sintered at 200~800 °C to obtain an in-situ supported catalyst on a porous ceramic support with a porosity greater than 90%.

[0018] Furthermore, the ceramic raw materials, auxiliary materials, and deionized water are uniformly mixed to form a ceramic slurry, including:

[0019] The ceramic raw materials are mixed to form a homogeneous mixture;

[0020] Adding excipients to deionized water forms an auxiliary agent solution. The excipients include a binder and a thixotropic agent. The mass of the binder is 0.05% to 0.20% of the total mass of the mixture, the mass of the thixotropic agent is 0.01% to 0.10% of the total mass of the mixture, and the mass of the deionized water is 40% to 60% of the sum of the mass of the mixture and the excipients.

[0021] The ceramic slurry is formed by uniformly mixing the mixed material with the additive solution.

[0022] Furthermore, the ceramic raw material comprises a mixture of component A, component B, and component C;

[0023] Component A is one or a mixture of more than one of quartz powder, fly ash, waste porcelain powder, and feldspar;

[0024] Component B is one or a mixture of more than one of kaolin, metakaolin, and montmorillonite;

[0025] Component C is one or a mixture of one or more of steel slag, limestone, electric furnace ash, dust collector ash, and blast furnace slag.

[0026] Furthermore, the mixture comprises the following components by weight percentage:

[0027] SiO2: 52.0%~63.5%; Al2O3: 9.5%~12.5%; Fe2O3: 5.5%~8.5%; CaO: 8.5%~13.5 %; MgO: 0%~1.0%; K2O: 0%~0.3%; Na2O: 0%~0.1%; P2O5: 0%~0.1%; SO3: 0%~0.1%;

[0028] And the unavoidable impurities in the remaining amount;

[0029] The sum of the weight percentages of the above components and impurities is 100%; and the loss on ignition of the mixture at 700~800 ℃ is 0%~13%.

[0030] Furthermore, the adhesive is one or a mixture of more than one of cross-linked polyacrylic acid resin, polyvinyl alcohol, and polyacrylamide; the thixotropic agent is one or a mixture of more than one of hydroxyethyl methylcellulose and hydroxypropyl methylcellulose.

[0031] Further, the porous organic template is immersed in a catalyst precursor suspension for 5-15 minutes, so that the catalyst precursor is loaded onto the internal pore surface of the porous organic template, to obtain a first intermediate template, comprising:

[0032] A suspension was prepared by placing the catalyst precursor powder in deionized water and stirring continuously, wherein the amount of the catalyst precursor powder was 10-20 wt% of the deionized water.

[0033] The porous organic template is immersed in the suspension for 5-15 minutes, then removed and dried at 100-130 °C to obtain the first intermediate template.

[0034] Furthermore, the catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate, and aluminum hydroxide.

[0035] Furthermore, the third intermediate template is sintered at 200~800 °C to obtain a porous ceramic support for in-situ supported catalyst with a porosity greater than 90%, wherein the sintering includes:

[0036] S61. The third intermediate template is heated from room temperature to the first temperature at a heating rate of 4~5 ℃ / min;

[0037] S62. The third intermediate template at the first temperature is heated to the second temperature at a heating rate of 3~5 °C / min;

[0038] S63. Maintain the second temperature for 10-30 minutes.

[0039] S64. The third intermediate template, which is at the second temperature, is heated to the third temperature at a heating rate of 1~3 °C / min;

[0040] S65. Maintain the third temperature for 5-10 minutes.

[0041] S66. Cool the third intermediate template at the third temperature to the fourth temperature at a cooling rate of 5~10 ℃ / min;

[0042] Wherein, the first temperature is 200℃, the second temperature is 200~250℃, the third temperature is 250~800℃, and the fourth temperature is 200~300℃.

[0043] Furthermore, the porous organic template is a polymer foam, which includes polyurethane foam and polyvinyl alcohol foam;

[0044] The pore density of the polymer foam is 30~50 PPI.

[0045] Secondly, a porous ceramic support in-situ supported catalyst prepared according to the above preparation method is provided.

[0046] The beneficial effects of this invention are:

[0047] The method for preparing in-situ supported catalysts on porous ceramic supports provided by this invention integrates the catalyst support fabrication process with the catalyst fabrication and loading process in a single low-temperature sintering process. This allows the catalyst to be more uniformly embedded in the porous support, reducing production steps and energy consumption, effectively utilizing solid waste resources, and the support has high mechanical strength, which is sufficient to form stable catalytic conditions in a high-pressure gas environment. The production process is continuous, with high production efficiency, and is suitable for large-scale industrial production.

[0048] On the one hand, this invention completes the loading of the catalyst precursor and the preparation of the porous support simultaneously, overcoming the technical bias of separating the loading of the porous support and the catalyst under different reaction conditions in the traditional technology. Specifically, through physical loading and chemical conversion mechanism, the catalyst precursor is loaded on the inner and outer surfaces of the porous support in advance by impregnation and spraying, and is converted into active catalytic components in situ during low-temperature sintering, reducing the secondary loading steps of the catalyst.

[0049] The physical loading mechanism utilizes the three-dimensional network structure of polymer foam as a template, and through a "supersaturated solution impregnation-cooling crystallization" process, the catalyst precursor is uniformly precipitated and attached to the inner surface of the foam. The chemical conversion mechanism utilizes a ceramic slurry with a specific formulation to solidify into a ceramic material during low-temperature sintering at 600~800℃. At the same time, the catalyst precursor is oxidized in situ and converted into active components, achieving in-situ catalyst loading. In this process, the pore size and bulk density of the porous support can be designed and adjusted through the precursor module, resulting in better planning and ensuring better catalyst loading effect and higher stability.

[0050] On the other hand, in response to the problems of uneven distribution of active components and weak bonding force between the catalyst and the support when the catalyst is loaded on a porous ceramic support in the prior art, the present invention preloads the catalyst precursor onto a polymer foam template. After sintering, the polymer foam template completely dissolves, and the ceramic skeleton formed by the ceramic preform directly wraps the catalyst particles, forming an "embedded" structure. This eliminates the clear interface between the catalyst and the support, fundamentally solving the problems of catalyst particle detachment and deactivation. Specifically, after 40 days of continuous operation, the activity retention rate reached 93.5%, and the catalyst detachment rate was only 3.4%.

[0051] On the other hand, after the polymer foam is impregnated with a supersaturated solution of the catalyst precursor, catalyst nuclei are uniformly precipitated on the surface of its internal pores. These nuclei guide the directional growth of the catalyst during subsequent sintering, causing a catalytically active layer to spontaneously form on the pore surface. Cooling and crystallization of the supersaturated solution further facilitates the uniform nucleation of the catalyst precursor on the pore surface of the polymer foam. In this case, nucleus growth is controlled by solution diffusion rather than by capillary migration as in traditional techniques, resulting in a more uniform distribution. Subsequent blowing further replenishes the catalyst particle loading on the template surface, forming a continuous film rather than discrete particles after sintering. This solves the problems of catalyst particle blockage and uneven distribution, significantly increasing the density of effective active sites and achieving better catalytic performance.

[0052] On the other hand, addressing the problem that existing organic polymer foam impregnation methods struggle to ensure unblocked pores and consistently produce high-porosity foam ceramics, this invention adds binders and thixotropic agents to the ceramic slurry. This modulates the slurry's rheological properties, fundamentally reducing its sensitivity to solid content and viscosity. Specifically, a specific proportion of thixotropic agent is added to the ceramic slurry to ensure uniform slurry coating on the foam skeleton without flow; during centrifugal discharge, shear stress disrupts the network structure, reducing viscosity; and a specific proportion of binder ensures smooth flow of the slurry through the three-dimensional channels without clogging. After centrifugation stops, the network structure rapidly rebuilds, and viscosity recovers, preventing slurry backflow. Through the synergistic effect of binders and thixotropic agents, the porosity of the porous carrier is stably maintained at over 90%. Furthermore, the thixotropic process is compatible with the catalyst blowing process, allowing catalyst powder to be blown immediately after slurry discharge. This utilizes the powder's adsorption of residual moisture to shorten drying time and avoids the risk of the airflow process blowing away the catalyst precursor.

[0053] In summary, this invention integrates the catalyst and catalyst support, eliminating the cumbersome multi-step processing steps of traditional preparation methods. This significantly shortens the preparation cycle, reduces the input of manpower, material resources, and time costs, and improves production efficiency. The preparation method is simpler, more efficient, and easier to scale up for production and industrial application, better meeting the needs of rapid production in modern industry and providing strong support for the mass production of porous ceramic catalyst supports.

[0054] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other. Attached Figure Description

[0055] The accompanying drawings are not drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures can be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings. The embodiments in the drawings do not constitute any limitation on the invention. Other drawings can be obtained by those skilled in the art based on the following drawings without inventive effort, wherein:

[0056] Figure 1 This is a schematic diagram of the entire process of preparing the in-situ supported catalyst on a porous ceramic support in this embodiment of the invention;

[0057] Figure 2 This is a schematic diagram of the process of supporting catalysts with porous organic templates in an embodiment of the present invention;

[0058] Figure 3 This is a schematic diagram of the catalyst loading principle in an embodiment of the present invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art.

[0060] The terms "first," "second," and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the features, integrals, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0061] In existing technologies, the sintering process of porous ceramic catalyst supports typically employs high-temperature sintering, i.e., temperatures exceeding 1000℃. Most metal-based catalysts deactivate at high temperatures. Therefore, the porous catalyst support and catalyst loading are separated into two steps, performed under different reaction conditions at high and low temperatures. This invention overcomes this technical bias by using a specific ceramic slurry formulation to directly form pores at a low temperature of 600-800℃ through the thermal decomposition of organic foam. This directly and simultaneously achieves the preparation of the porous support and the loading of catalyst particles, without the need for a high-temperature liquid phase. Specifically, it provides a method for in-situ loading of catalysts onto porous ceramic supports and their low-temperature co-sintering preparation.

[0062] This invention involves uniformly mixing ceramic raw materials, auxiliary materials, and deionized water to form a ceramic slurry; using an impregnation method, a catalyst precursor is loaded onto the surface of the internal pores, channels, or voids of a porous organic template, then removed and impregnated in the ceramic slurry, and after removing and draining the slurry, catalyst precursor powder is sprayed onto its surface, followed by sintering treatment to obtain an in-situ supported catalyst on a porous ceramic support.

[0063] Specifically, it includes:

[0064] Ceramic raw materials, auxiliary materials, and deionized water are uniformly mixed to form a ceramic slurry; the auxiliary materials are used to give the ceramic slurry rheological properties so as to maintain structural stability during impregnation and slurry discharge.

[0065] The porous organic template is immersed in the catalyst precursor suspension for 5-15 minutes, so that the catalyst precursor is loaded on the internal pore surface of the porous organic template to obtain the first intermediate template.

[0066] The first intermediate template is taken out and immersed in the ceramic slurry for 5-20 minutes. It is then removed and the slurry is drained to obtain the second intermediate template covered with the ceramic body.

[0067] Catalyst precursor powder is sprayed onto the surface of the second intermediate template to obtain a third intermediate template, wherein the amount of catalyst precursor powder sprayed is 2.5~5.0% of the mass of the second intermediate template;

[0068] The third intermediate template is sintered at 200~800 °C to obtain an in-situ supported catalyst on a porous ceramic support with a porosity greater than 90%.

[0069] See attached document Figure 1 As shown, this invention discloses a method for preparing an in-situ supported catalyst on a porous ceramic support, specifically including the following steps:

[0070] S1. Mix the ceramic raw materials in a certain proportion to form a homogeneous mixture; add auxiliary materials to deionized water to form an additive solution; mix the homogeneous mixture and the additive solution evenly to form a ceramic slurry.

[0071] S2, see appendix Figure 2 The catalyst precursor powder is loaded onto a porous organic template by impregnation. The specific steps include:

[0072] S21. Place the catalyst precursor powder in deionized water and stir continuously until a suspension is formed to obtain the catalyst precursor, wherein the amount of catalyst precursor powder is 10-20 wt% of deionized water, and the mass of deionized water in the suspension is 40-50% of the mass of ceramic slurry;

[0073] S22. Slowly and thoroughly immerse the porous organic template in the suspension for 5-15 minutes to obtain the pretreated porous organic template.

[0074] S23. Quickly remove the pretreated porous organic template and heat it to dry. Specifically, dry and dehydrate it at 100~130℃ to obtain the post-treated porous organic template, i.e., the first intermediate template.

[0075] For details, please refer to the appendix. Figure 3 The porous organic template is immersed in a suspension, and the tiny pores inside the porous organic template are fully filled by the liquid. During the subsequent heating and drying, the catalyst precursor particles in the solution gradually and uniformly adhere to the pore surface inside the porous organic template.

[0076] The drying conditions were as follows: at 120 ℃, the vacuum degree was controlled at -0.06 ~ -0.09 MPa in a vacuum drying oven for 1~2 h.

[0077] S3. Immerse the first intermediate template in the ceramic slurry for 5 to 20 minutes to ensure that the ceramic slurry fully fills the foam skeleton of the first intermediate template.

[0078] S4. After impregnation, remove the mold and use a centrifuge or roller to drain excess slurry, thus obtaining a second intermediate template covered with ceramic blank.

[0079] S5. The catalyst precursor powder is sprayed onto the surface of the second intermediate template and then dried to obtain the third intermediate template. Specifically, an electrostatic powder spraying gun is used to carry out the spraying operation in an environment with humidity below 20%. The spraying is done by directly using dry catalyst precursor powder. 2.5~5g of catalyst precursor powder is sprayed onto every 100g of the second intermediate template, and then it is dried quickly to prevent the catalyst precursor from sticking together.

[0080] The drying conditions were as follows: at 120 ℃, the vacuum degree was controlled at -0.06 ~ -0.09 MPa in a vacuum drying oven for 1~2 h.

[0081] S6. Sinter the third intermediate template to obtain the in-situ supported catalyst on a porous ceramic support. The sintering process includes the following steps:

[0082] S61. The third intermediate template is heated from room temperature to the first temperature at a heating rate of 4~5 ℃ / min;

[0083] S62. The third intermediate template at the first temperature is heated to the second temperature at a heating rate of 3~5 ℃ / min;

[0084] S63. Maintain the second temperature for 10-30 minutes.

[0085] S64. The third intermediate template at the second temperature is heated to the third temperature at a heating rate of 1~3 ℃ / min;

[0086] S65. Maintain the third temperature for 5-10 minutes.

[0087] S66. Cool the third intermediate template at the third temperature to the fourth temperature at a cooling rate of 5~10 ℃ / min.

[0088] The first temperature is 200℃, the second temperature is 200~250℃, the third temperature is 250~800℃, and the fourth temperature is 200~300℃. To prevent the ceramic from cracking during subsequent cooling, the fourth temperature is preferably 200℃.

[0089] The above-mentioned ceramic raw materials include a mixture of component A, component B, and component C, wherein:

[0090] Component A is a lean material, specifically a mixture of one or more of the following: quartz powder, fly ash, waste porcelain powder, and feldspar.

[0091] Component B is a plastic material, specifically a mixture of one or more of kaolin, metakaolin, and montmorillonite;

[0092] Component C is a flux, specifically one or more of steel slag, limestone, electric furnace ash, dust collector ash, and blast furnace slag.

[0093] The above-mentioned mixture comprises the following components by weight percentage:

[0094] SiO2: 52.0%~63.5%; Al2O3: 9.5%~12.5%; Fe2O3: 5.5%~8.5%; CaO: 8.5%~13.5 %; MgO: 0%~1.0%; K2O: 0%~0.3%; Na2O: 0%~0.1%; P2O5: 0%~0.1%; SO3: 0%~0.1%;

[0095] And the unavoidable impurities in the remaining amount;

[0096] The sum of the weight percentages of the above components and impurities is 100%; and the loss on ignition of the mixture at 700~800 ℃ is 0%~13%.

[0097] Specifically, the weight percentage of each component was determined by X-ray fluorescence spectroscopy; the loss on ignition was determined by gravimetric method, which involved weighing a certain amount of sample and burning it in a high-temperature furnace at 1000℃ until constant weight, and the mass difference before and after burning was the loss on ignition.

[0098] The solid waste used in the aforementioned ceramic raw materials includes materials containing silicon, calcium, and aluminum, such as steel slag, water slag, and iron tailings. By transforming these solid wastes into valuable resources, their added value is increased, creating additional economic benefits.

[0099] To achieve low-temperature sintering, this invention utilizes a high-basicity flux to significantly lower the eutectic point of the ceramic system. Specifically, in the low-temperature range of 600–900 °C, the flux preferentially melts to form a highly fluid liquid phase, filling the gaps between ceramic particles. Its consolidation principle is based on a liquid-phase sintering mechanism: the ceramic skeleton mainly relies on a stable three-dimensional network structure formed by silicon-oxygen or aluminum-oxygen tetrahedra, which has an extremely high melting point. Upon introducing a high-basicity component, the free oxygen ions it provides strongly attack and break the bridging oxygen bonds in these network structures, transforming them into non-bridging oxygen bonds. This process causes the originally continuous high-melting-point crystal network to disintegrate into short chains or oligomers, significantly reducing the degree of polymerization and melting activation energy of the system. Simultaneously, alkali metal ions, with their large radius and low charge, generate strong lattice distortion after embedding into the network voids, further weakening the bonding force. This structural "fragmentation" allows the system to overcome the lattice energy barrier at temperatures far below the melting point of the raw materials, resulting in localized melting and the formation of a liquid phase, thereby achieving low-temperature eutectic consolidation.

[0100] The aforementioned auxiliary materials include binders and thixotropic agents.

[0101] Specifically, the adhesive is one or a mixture of more than one of cross-linked polyacrylic acid resin, polyvinyl alcohol, and polyacrylamide; the thixotropic agent is one or a mixture of more than one of hydroxyethyl methylcellulose and hydroxypropyl methylcellulose.

[0102] The binder accounts for 0.05% to 0.20% of the total mass of the mixture, the thixotropic agent accounts for 0.01% to 0.10% of the total mass of the mixture, and the deionized water accounts for 40% to 60% of the sum of the mass of the mixture and the auxiliary materials.

[0103] The above-mentioned scheme modulates the rheological properties of the slurry by adding binders and thixotropic agents, fundamentally reducing the sensitivity to the solid content and viscosity of the ceramic slurry. The synergistic effect of the binders and thixotropic agents ensures uniform slurry coating on the ceramic skeleton without flow. During subsequent centrifugal discharge, shear stress disrupts the network structure, reducing viscosity and allowing the slurry to flow smoothly out of the three-dimensional channels without clogging. After centrifugation stops, the network structure is rapidly rebuilt, and the viscosity recovers, preventing slurry backflow. This prevents incomplete slurry discharge and channel blockage, significantly increasing the porosity of the porous carrier.

[0104] The catalyst precursor described above is a mixture of copper oxide, basic zinc carbonate, and aluminum hydroxide. The specific components and their proportions can be adjusted according to actual conditions and needs. The amount of catalyst precursor powder and the particle size can be adjusted based on the template porosity and actual requirements.

[0105] Specifically, in the above-mentioned catalyst precursor, the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is (0.74 ~ 1.24): 1: (0.30 ~ 0.91); preferably, the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.93:1:0.61.

[0106] Meanwhile, refer to the appendix Figure 3 By adding binders and thixotropic agents to the ceramic slurry, the porous organic template is fully impregnated during the impregnation process, allowing it to take shape and maintain a fixed form. The subsequently sprayed catalyst precursor powder can also be stably adsorbed onto the surface of the ceramic slurry, thus being stably loaded onto the outer surface of the third intermediate template. After the sintering process, the polymer organic template is melted, and the ceramic green body gradually vitrifies. During this process, the catalyst precursors copper oxide, basic zinc carbonate, and aluminum hydroxide undergo chemical transformation, converting into the catalyst active components, namely copper oxide, zinc oxide, and aluminum oxide, respectively. Finally, a porous ceramic support for in-situ catalyst loading with numerous catalyst active sites uniformly distributed on both the inner and outer surfaces is obtained.

[0107] The aforementioned porous organic template is a polymer foam, which includes polyurethane foam and polyvinyl alcohol foam; specifically, it includes, but is not limited to, any one of polyurethane foam and polyvinyl alcohol foam.

[0108] The pore density of the above polymer foam is 30~50 PPI, specifically determined according to GB / T 1234 standard or by microscopic counting method.

[0109] The above preparation method reduces the foaming process and does not require the participation of high-temperature liquid phase, which greatly reduces the firing temperature and significantly reduces energy consumption during the production process. It also reduces carbon emissions. The final product has an open porosity of more than 90% and a surface covered with a large number of micropores and catalyst sites, which greatly improves the reaction rate and load.

[0110] The porous ceramic support in-situ supported catalyst and its preparation method disclosed in this invention will be further described in detail below with reference to specific embodiments. Unless otherwise specified, the reagents and materials used in the examples and comparative examples are all commercially available, and the specific product models and other information are as follows:

[0111] Cross-linked polyacrylic acid resin: purchased from Shanghai Maclean Research Reagents, product model C886117.

[0112] Polyvinyl alcohol: Purchased from Shanghai Maclean Research Reagents, product model P823118.

[0113] Polyacrylamide: Purchased from Shanghai Maclean Research Reagents, product model PHIII.

[0114] Hydroxyethyl methylcellulose: Purchased from Shanghai Maclean Research Reagents, product model S14168.

[0115] Hydroxypropyl methylcellulose: Purchased from Shanghai Maclean Research Reagents, Type I.

[0116] Polyurethane foam: Polyurethane foam sponge is used and purchased from Keda New Materials Products.

[0117] Polyvinyl alcohol foam: Polyvinyl alcohol foam sponge is used and purchased from Keda New Materials Products.

[0118] Example 1

[0119] A method for preparing an in-situ supported catalyst on a porous ceramic support includes the following steps:

[0120] S1. Mix the ceramic raw materials according to the proportion to form a homogeneous material of 200g; add the auxiliary materials to the deionized water to form an additive solution; mix the homogeneous material and the additive solution evenly to form a ceramic slurry;

[0121] S2. Place 20g of catalyst precursor powder in 100g of deionized water and stir continuously until a suspension is formed; slowly and thoroughly immerse the porous organic template in the suspension for 10 min to obtain a pretreated porous organic template; quickly remove the pretreated porous organic template and place it in a vacuum drying oven at 120 ℃ with a vacuum degree controlled at -0.08MPa for 1.5 h to obtain a post-treated porous organic template;

[0122] S3. Immerse the post-processed porous organic template in the ceramic slurry for 5 minutes.

[0123] S4. After impregnation, remove the ceramic body and use a centrifuge or drum to drain the excess slurry, thus obtaining the ceramic body.

[0124] S5. The catalyst precursor powder is sprayed onto the surface of the ceramic body, and then placed in a vacuum drying oven at 120°C with a vacuum degree controlled at -0.08MPa for 1.5 hours. The amount of catalyst precursor powder sprayed is 5.0% of the mass of the ceramic body.

[0125] S6. Sinter the dried ceramic preform to obtain a porous ceramic support for in-situ supported catalyst. The sintering process includes the following steps:

[0126] S61. The ceramic body is heated from room temperature (20°C) to 200°C at a heating rate of 5°C / min.

[0127] S62. The ceramic body at 200℃ is heated to 250℃ at a heating rate of 5℃ / min.

[0128] S63. Maintain 250℃ for 30 minutes;

[0129] S64. The ceramic body at 250℃ is heated to 800℃ at a heating rate of 3℃ / min;

[0130] S65, maintain 800℃ for 10 minutes;

[0131] S66. The ceramic body at 800°C is cooled to 200°C at a cooling rate of 10°C / min, and then allowed to cool naturally.

[0132] The above-mentioned ceramic raw materials consist of the following components in parts by weight: 4 parts quartz, 5 parts feldspar, 5 parts kaolin, 2 parts steel slag powder, and 4 parts dust collector ash; X-ray fluorescence spectrometry analysis revealed that the homogenized material contains the following components by weight percentage: SiO2 58.5%, Al2O3 11.2%, Fe2O3 6.8%, CaO 10.5%, MgO 0.6%, K2O 0.15%, Na2O 0.1%, and the balance being unavoidable impurities; the sum of the weight percentages of the above components and impurities is 100%, and the loss on ignition of the above homogenized material at 800 °C is 12.1%.

[0133] The aforementioned excipients include a binder and a thixotropic agent. The binder is polyvinyl alcohol, and its mass is 0.10% of the total mass of the mixture. The thixotropic agent is hydroxypropyl methylcellulose, and its mass is 0.10% of the total mass of the mixture. The mass of deionized water in the excipient solution is 50% of the sum of the mass of the mixture and the excipients.

[0134] The aforementioned porous organic template is made of polyurethane foam with a pore density of 30 PPI.

[0135] The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate and aluminum hydroxide, wherein the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.93:1:0.61.

[0136] Example 2

[0137] A method for preparing an in-situ supported catalyst on a porous ceramic support includes the following steps:

[0138] S1. Mix the ceramic raw materials according to the proportion to form a homogeneous material of 200g; add the auxiliary materials to the deionized water to form an additive solution; mix the homogeneous material and the additive solution evenly to form a ceramic slurry;

[0139] S2. Place 20g of catalyst precursor powder in 100g of deionized water and stir continuously until a suspension is formed; slowly and thoroughly immerse the porous organic template in the suspension for 5 min to obtain a pretreated porous organic template; quickly remove the pretreated porous organic template and place it in a vacuum drying oven at 130 ℃ with a vacuum degree controlled at -0.08MPa for 1.5 h to obtain a post-treated porous organic template.

[0140] S3. Immerse the post-processed porous organic template in the ceramic slurry for 5 minutes.

[0141] S4. After impregnation, remove the ceramic body and use a centrifuge or drum to drain the excess slurry, thus obtaining the ceramic body.

[0142] S5. The catalyst precursor powder is sprayed onto the surface of the ceramic body, and then placed in a vacuum drying oven at 130°C with a vacuum degree controlled at -0.08MPa for 1.5 hours. The amount of catalyst precursor powder sprayed is 4.0% of the mass of the ceramic body.

[0143] S6. Sinter the dried ceramic preform to obtain a porous ceramic support for in-situ supported catalyst. The sintering process includes the following steps:

[0144] S61. The ceramic body is heated from room temperature (20°C) to 200°C at a heating rate of 4°C / min.

[0145] S62. The ceramic body at 200℃ is heated to 250℃ at a heating rate of 5℃ / min.

[0146] S63. Maintain 250℃ for 20 minutes;

[0147] S64. The ceramic body at 250℃ is heated to 800℃ at a heating rate of 3℃ / min;

[0148] S65. Maintain 800℃ for 5 minutes;

[0149] S66. The ceramic body at 800°C is cooled to 200°C at a cooling rate of 10°C / min, and then allowed to cool naturally.

[0150] The above-mentioned ceramic raw materials consist of the following components in parts by weight: 4 parts fly ash, 6 parts waste ceramic powder, 3 parts feldspar, 1 part montmorillonite, 4 parts blast furnace slag, and 2 parts electric furnace ash. X-ray fluorescence spectroscopy revealed the following components by weight percentage: SiO2 58.0%, Al2O3 11.0%, Fe2O3 7.0%, CaO 11.0%, MgO 0.6%, K2O 0.2%, Na2O 0.1%, and the balance being unavoidable impurities. The sum of the weight percentages of the above components and impurities is 100%, and the loss on ignition of the above-mentioned mixture at 800℃ is 12.1%.

[0151] The aforementioned excipients include a binder and a thixotropic agent. The binder is polyvinyl alcohol, and its mass is 0.10% of the total mass of the mixture. The thixotropic agent is hydroxypropyl methylcellulose, and its mass is 0.10% of the total mass of the mixture. The mass of deionized water in the excipient solution is 50% of the sum of the mass of the mixture and the excipients.

[0152] The aforementioned porous organic template is made of polyurethane foam with a pore density of 35 PPI.

[0153] The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate and aluminum hydroxide, wherein the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.9:1:0.6.

[0154] Example 3

[0155] A method for preparing an in-situ supported catalyst on a porous ceramic support includes the following steps:

[0156] S1. Mix the ceramic raw materials according to the proportion to form a homogeneous material of 200g; add the auxiliary materials to the deionized water to form an additive solution; mix the homogeneous material and the additive solution evenly to form a ceramic slurry;

[0157] S2. Place 20g of catalyst precursor powder in 100g of deionized water and stir continuously until a suspension is formed; slowly and thoroughly immerse the porous organic template in the suspension for 10 min to obtain a pretreated porous organic template; quickly remove the pretreated porous organic template and place it in a vacuum drying oven at 100 ℃ with a vacuum degree controlled at -0.08MPa for 1.5 h to obtain a post-treated porous organic template.

[0158] S3. Immerse the post-processed porous organic template in the ceramic slurry for 5 minutes.

[0159] S4. After impregnation, remove the ceramic body and use a centrifuge or drum to drain the excess slurry, thus obtaining the ceramic body.

[0160] S5. The catalyst precursor powder is sprayed onto the surface of the ceramic body, and then placed in a vacuum drying oven at 100°C with a vacuum degree controlled at -0.08MPa for 1.5 hours. The amount of catalyst precursor powder sprayed is 3.0% of the mass of the ceramic body.

[0161] S6. Sinter the dried ceramic preform to obtain a porous ceramic support for in-situ supported catalyst. The sintering process includes the following steps:

[0162] S61. The ceramic body is heated from room temperature (20°C) to 200°C at a heating rate of 4°C / min.

[0163] S62. The ceramic body at 200℃ is heated to 250℃ at a heating rate of 5℃ / min.

[0164] S63. Maintain 250℃ for 20 minutes;

[0165] S64. The ceramic body at 250℃ is heated to 800℃ at a heating rate of 3℃ / min;

[0166] S65. Maintain 800℃ for 5 minutes;

[0167] S66. The ceramic body at 800°C is cooled to 200°C at a cooling rate of 10°C / min, and then allowed to cool naturally.

[0168] The above-mentioned ceramic raw materials consist of the following components in parts by weight: 4 parts fly ash, 6 parts waste ceramic powder, 3 parts feldspar, 1 part montmorillonite, 4 parts blast furnace slag, and 2 parts electric furnace ash. X-ray fluorescence spectroscopy revealed the following components by weight percentage: SiO2 58.0%, Al2O3 11.0%, Fe2O3 7.0%, CaO 11.0%, MgO 0.6%, K2O 0.2%, Na2O 0.1%, and the balance being unavoidable impurities. The sum of the weight percentages of the above components and impurities is 100%, and the loss on ignition of the above-mentioned mixture at 800℃ is 12.1%.

[0169] The aforementioned excipients include a binder and a thixotropic agent. The binder is polyvinyl alcohol, and its mass is 0.10% of the total mass of the mixture. The thixotropic agent is hydroxypropyl methylcellulose, and its mass is 0.10% of the total mass of the mixture. The mass of deionized water in the excipient solution is 45% of the sum of the mass of the mixture and the excipients.

[0170] The aforementioned porous organic template is made of polyurethane foam with a pore density of 36 PPI.

[0171] The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate and aluminum hydroxide, wherein the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.93:1:0.61.

[0172] Example 4

[0173] A method for preparing an in-situ supported catalyst on a porous ceramic support includes the following steps:

[0174] S1. Mix the ceramic raw materials according to the proportion to form a homogeneous material of 200g; add the auxiliary materials to the deionized water to form an additive solution; mix the homogeneous material and the additive solution evenly to form a ceramic slurry;

[0175] S2. Place 20g of catalyst precursor powder in 100g of deionized water and stir continuously until a suspension is formed; slowly and thoroughly immerse the porous organic template in the suspension for 10 min to obtain a pretreated porous organic template; quickly remove the pretreated porous organic template and place it in a vacuum drying oven at 100 ℃ with a vacuum degree controlled at -0.08MPa for 1.5 h to obtain a post-treated porous organic template.

[0176] S3. Immerse the post-processed porous organic template in the ceramic slurry for 5 minutes.

[0177] S4. After impregnation, remove the ceramic body and use a centrifuge or drum to drain the excess slurry, thus obtaining the ceramic body.

[0178] S5. The catalyst precursor powder is sprayed onto the surface of the ceramic body, and then placed in a vacuum drying oven at 100°C with a vacuum degree controlled at -0.08MPa for 1.5 hours. The amount of catalyst precursor powder sprayed is 2.5% of the mass of the ceramic body.

[0179] S6. Sinter the dried ceramic preform to obtain a porous ceramic support for in-situ supported catalyst. The sintering process includes the following steps:

[0180] S61. The ceramic body is heated from room temperature (20°C) to 200°C at a heating rate of 4°C / min.

[0181] S62. The ceramic body at 200℃ is heated to 250℃ at a heating rate of 5℃ / min.

[0182] S63. Maintain 250℃ for 20 minutes;

[0183] S64. The ceramic body at 250℃ is heated to 800℃ at a heating rate of 3℃ / min;

[0184] S65, maintain 800℃ for 6 minutes;

[0185] S66. The ceramic body at 800°C is cooled to 200°C at a cooling rate of 10°C / min, and then allowed to cool naturally.

[0186] The above-mentioned ceramic raw materials consist of the following components in parts by weight: 4 parts fly ash, 6 parts waste ceramic powder, 3 parts feldspar, 1 part montmorillonite, 4 parts blast furnace slag, and 2 parts electric furnace ash. X-ray fluorescence spectroscopy revealed the following components by weight percentage: SiO2 58.0%, Al2O3 11.0%, Fe2O3 7.0%, CaO 11.0%, MgO 0.6%, K2O 0.2%, Na2O 0.1%, and the balance being unavoidable impurities. The sum of the weight percentages of the above components and impurities is 100%, and the loss on ignition of the above-mentioned mixture at 800℃ is 12.1%.

[0187] The aforementioned excipients include a binder and a thixotropic agent. The binder is cross-linked polyacrylic acid resin, and its mass is 0.10% of the total mass of the mixture. The thixotropic agent is hydroxyethyl methyl cellulose, and its mass is 0.10% of the total mass of the mixture. The mass of deionized water in the excipient solution is 45% of the sum of the mass of the mixture and the excipients.

[0188] The aforementioned porous organic template is made of polyurethane foam with a pore density of 50 PPI.

[0189] The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate and aluminum hydroxide, wherein the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.93:1:0.61.

[0190] Example 5

[0191] A method for preparing an in-situ supported catalyst on a porous ceramic support includes the following steps:

[0192] S1. Mix the ceramic raw materials according to the proportion to form a homogeneous material of 200g; add the auxiliary materials to the deionized water to form an additive solution; mix the homogeneous material and the additive solution evenly to form a ceramic slurry;

[0193] S2. Place 20g of catalyst precursor powder in 100g of deionized water and stir continuously until a suspension is formed; slowly and thoroughly immerse the porous organic template in the suspension for 15 min to obtain a pretreated porous organic template; quickly remove the pretreated porous organic template and place it in a vacuum drying oven at 130 ℃ with a vacuum degree controlled at -0.08MPa for 1.5 h to obtain a post-treated porous organic template;

[0194] S3. Immerse the post-processed porous organic template in the ceramic slurry for 15 minutes.

[0195] S4. After impregnation, remove the ceramic body and use a centrifuge or drum to drain the excess slurry, thus obtaining the ceramic body.

[0196] S5. The catalyst precursor powder is sprayed onto the surface of the ceramic body, and then placed in a vacuum drying oven at 120°C with a vacuum degree controlled at -0.08MPa for 1.5 hours. The amount of catalyst precursor powder sprayed is 5.0% of the mass of the ceramic body.

[0197] S6. Sinter the dried ceramic preform to obtain a porous ceramic support for in-situ supported catalyst. The sintering process includes the following steps:

[0198] S61. The ceramic body is heated from room temperature (20°C) to 200°C at a heating rate of 4°C / min.

[0199] S62. The ceramic body at 200℃ is heated to 250℃ at a heating rate of 5℃ / min.

[0200] S63. Maintain 250℃ for 20 minutes;

[0201] S64. The ceramic body at 250℃ is heated to 800℃ at a heating rate of 3℃ / min;

[0202] S65. Maintain 800℃ for 5 minutes;

[0203] S66. The ceramic body at 800°C is cooled to 200°C at a cooling rate of 10°C / min, and then allowed to cool naturally.

[0204] The above-mentioned ceramic raw materials consist of the following components in parts by weight: 4 parts fly ash, 6 parts waste ceramic powder, 3 parts feldspar, 1 part montmorillonite, 4 parts blast furnace slag, and 2 parts electric furnace ash. X-ray fluorescence spectroscopy revealed the following components by weight percentage: SiO2 58.0%, Al2O3 11.0%, Fe2O3 7.0%, CaO 11.0%, MgO 0.6%, K2O 0.2%, Na2O 0.1%, and the balance being unavoidable impurities. The sum of the weight percentages of the above components and impurities is 100%, and the loss on ignition of the above-mentioned mixture at 800℃ is 12.1%.

[0205] The aforementioned excipients include a binder and a thixotropic agent. The binder is polyvinyl alcohol, and its mass is 0.10% of the total mass of the mixture. The thixotropic agent is hydroxypropyl methylcellulose, and its mass is 0.10% of the total mass of the mixture. The mass of deionized water in the excipient solution is 45% of the sum of the mass of the mixture and the excipients.

[0206] The aforementioned porous organic template uses polyvinyl alcohol foam with a pore density of 35 PPI.

[0207] The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate and aluminum hydroxide, wherein the mass ratio of copper oxide, basic zinc carbonate and aluminum hydroxide is 0.93:1:0.61.

[0208] Comparative Example 1

[0209] The difference between Comparative Example 1 and Example 1 above is that no binder and thixotropic agent were added.

[0210] Comparative Example 2

[0211] The difference between Comparative Example 2 and Example 1 above is that no adhesive was added.

[0212] Comparative Example 3

[0213] The difference between Comparative Example 3 and Example 1 above is that no thixotropic agent was added.

[0214] Performance testing

[0215] To better verify the performance of the in-situ supported catalysts on porous ceramic supports obtained in the above embodiments and comparative examples, the materials prepared in the above comparative examples and embodiments were subjected to performance testing.

[0216] The catalyst products obtained in Examples 1-5 and Comparative Examples 1-3 were processed into standard test specimens of 30mm x 20mm x 10mm and dried in an oven to constant weight. Subsequently, performance tests were performed on porosity / wrinkle ratio, compressive strength, and bulk density.

[0217] The above performance indicators were all tested using existing known methods, and the specific test methods are as follows:

[0218] Porosity test: The Archimedes' displacement method was used, referring to GB / T 1966-1996 standard. After drying the sample to constant weight, the mass m1 of the dried sample was measured sequentially. The sample was then boiled in boiling water for 2 hours to completely fill the pores with water. After cooling, the buoyant weight of the saturated sample in water, i.e., the saturated wet weight m2, was measured. The sample was removed, excess moisture was wiped off, and the mass m3 of the saturated sample in air was measured. The final mass m3 was calculated using the following formula:

[0219] Porosity = [(m3-m1) / (m3-m2)] x 100%.

[0220] Bulk density test: The Archimedes' water displacement method was used, referring to GB / T 1966-1996 standard. After drying the sample to constant weight, the following measurements were taken sequentially: the mass of the dried sample (m1), the saturated wet weight of the sample (m2, i.e., the apparent mass of the sample after being fully immersed in water), and the mass of the saturated sample in air (m3). The results were calculated using the following formula:

[0221] Bulk density = [(m1 x ρ) / (m3 - m2)] x 100%, where ρ is the density of pure water.

[0222] Compressive strength test: The test was conducted using a universal testing machine in accordance with GB / T 1964-1996 standard. The specimen was placed in the center of the testing machine platform, and pressure was applied uniformly at a loading rate of 0.5 mm / min until the specimen failed. The maximum failure load was recorded as F. The compressive strength was calculated using the following formula:

[0223] Compressive strength = F / S, where S is the area of ​​the specimen subjected to compression, in mm². 2 .

[0224] The specific test results of Examples 1-5 and Comparative Examples 1-3 are shown in Table 1 and Table 2, respectively.

[0225] Table 1. Performance test results of in-situ supported catalysts on porous ceramic supports obtained in Examples 1-5

[0226] Testing items unit Example 1 Example 2 Example 3 Example 4 Example 5 Porosity % 90.25 88.5 91.7 89.8 87.4 compressive strength MPa 3.7 4.2 3.9 4.0 4.0 Bulk density <![CDATA[g / cm 3 ]]> 0.41 0.45 0.42 0.45 0.48

[0227] Table 2. Performance test results of in-situ supported catalysts on porous ceramic supports obtained in Comparative Examples 1-3

[0228] Testing items unit Comparative Example 1 Comparative Example 2 Comparative Example 3 Porosity % 76.2 92 89.8 compressive strength MPa 2.2 2.3 2.1 Bulk density <![CDATA[g / cm 3 ]]> 0.61 0.24 0.46

[0229] As can be seen from the results in Tables 1 and 2, the porous ceramic support in-situ supported catalyst prepared by this invention has excellent properties, combining high porosity with good mechanical strength.

[0230] Specifically, the porous ceramic support for in-situ supported catalyst prepared in this embodiment of the invention has a porosity greater than 90%, and its surface is widely covered with a large number of micropores and catalyst sites. The high porosity ensures smooth gas flow inside the catalyst support, enhances the contact area and mass transfer efficiency between the gas and solid phases, and provides more reaction channels and space for the catalytic reaction.

[0231] As can be seen from the test data of Example 1 and Comparative Examples 1-3, the absence of thixotropic agent and binder leads to a significant decrease in the porosity and compressive strength of the catalyst, indicating that the ceramic skeleton has poor slurry drainage effect and clogs the pores. At the same time, although the addition of thixotropic agent alone slightly improves the porosity, the compressive strength and bulk density are significantly reduced. The addition of binder alone leads to a significant decrease in both porosity and compressive strength. This indicates that the simultaneous addition of thixotropic agent and binder, with their synergistic effect, regulates the rheological properties of the slurry and can significantly increase the open porosity of the porous carrier.

[0232] The catalyst products obtained in Examples 1-5 and Comparative Examples 1-3 were loaded into a fixed-bed reactor and reacted at a temperature of 220°C, a pressure of 3 MPa, and a space velocity of 6000 h⁻¹. -1 CO2 was hydrogenated to methanol under the condition of CO2 / H2 = 1:3. The reaction products were analyzed by gas chromatography to obtain the CO2 conversion rate, methanol selectivity and methanol space-time yield of the catalyst. After running continuously under the same reaction conditions for 40 days, the methanol space-time yield was recorded, and the activity retention rate and catalyst shedding rate were calculated.

[0233] The specific test results of Examples 1-5 and Comparative Examples 1-3 are shown in Tables 3 and 4, respectively.

[0234] Table 3. Performance test results of in-situ supported catalysts on porous ceramic supports obtained in Examples 1-5

[0235] Testing items unit Example 1 Example 2 Example 3 Example 4 Example 5 <![CDATA[CO2 conversion rate]]> % 18 16.5 16.2 16.3 16.5 Methanol selectivity % 95 94 94.2 94 94.5 Methanol space-time yield g / (kg·h) 312.5 298 305 306 310 Activity retention rate % 93.5 91.5 92.0 92.5 93.2 Catalyst shedding rate % 3.4 2.8 2.5 2.5 2.2

[0236] Table 4. Performance test results of in-situ supported catalysts on porous ceramic supports obtained in Comparative Examples 1-3

[0237] Testing items unit Comparative Example 1 Comparative Example 2 Comparative Example 3 <![CDATA[CO2 conversion rate]]> % 10.2 3.5 11.2 Methanol selectivity % 91 71 86.5 Methanol space-time yield g / (kg·h) 145 18 145 Activity retention rate % 87.5 85 65 Catalyst shedding rate % 18.5 10 12.5

[0238] As can be seen from the results in Tables 3 and 4, the porous ceramic support in-situ supported catalyst prepared in this invention has excellent catalytic properties and is suitable for the reaction of carbon dioxide hydrogenation to methanol. The catalyst prepared in the examples has excellent catalytic efficiency, with a CO2 conversion rate of 18%, a methanol selectivity of 95%, and a methanol space-time yield of 312.5 g / (kg·h).

[0239] As can be seen from the test data of Example 1 and Comparative Examples 1-3, the lack of addition of thixotropic agents and binders leads to a significant reduction in catalyst performance. This is because the number of active sites on the catalyst decreases significantly, which in turn leads to a decrease in its performance. At the same time, the lack of synergistic effect between thixotropic agents and binders results in insufficient stability of the catalyst powder loaded on the surface of the ceramic skeleton, which leads to a significant decrease in its activity retention rate and a significant increase in the catalyst shedding rate.

[0240] Specifically, the porous ceramic support in-situ supported catalyst prepared in this embodiment of the invention has a large number of micropores and catalyst sites, providing abundant anchoring points for the active components of the catalyst. This is beneficial for improving the dispersion and utilization rate of the catalyst, thereby greatly enhancing the rate and loading of the catalytic reaction. As a result, this catalyst support can exert excellent catalytic performance in the reaction of CO2 and H2 to synthesize methanol, significantly improving CO2 conversion efficiency and methanol selectivity. At the same time, the preparation method used in this embodiment ensures that the catalyst particles are tightly loaded on the inner and outer surfaces of the catalyst support, greatly improving the stability of the catalyst. Specifically, after 40 days of continuous operation, the activity retention rate reached 93.5%, and the catalyst shedding rate was only 3.4%, providing key support for improving methanol synthesis efficiency and reducing production costs.

[0241] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0242] The preparation method of in-situ supported catalyst on a porous ceramic support provided in the embodiments of this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing an in-situ supported catalyst on a porous ceramic support, characterized in that, include: Ceramic raw materials, auxiliary materials, and deionized water are uniformly mixed to form a ceramic slurry; the auxiliary materials are used to give the ceramic slurry rheological properties so as to maintain structural stability during impregnation and slurry discharge. The porous organic template is immersed in the catalyst precursor suspension for 5-15 minutes, so that the catalyst precursor is loaded on the internal pore surface of the porous organic template to obtain the first intermediate template. The first intermediate template is taken out and immersed in the ceramic slurry for 5-20 minutes. It is then removed and the slurry is drained to obtain the second intermediate template covered with the ceramic body. Catalyst precursor powder is sprayed onto the surface of the second intermediate template to obtain a third intermediate template, wherein the amount of catalyst precursor powder sprayed is 2.5~5.0% of the mass of the second intermediate template; The third intermediate template is sintered at 200~800 °C to obtain an in-situ supported catalyst on a porous ceramic support with a porosity greater than 90%.

2. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 1, characterized in that, The ceramic raw materials, auxiliary materials, and deionized water are uniformly mixed to form a ceramic slurry, including: The ceramic raw materials are mixed to form a homogeneous mixture; Adding excipients to deionized water forms an auxiliary agent solution. The excipients include a binder and a thixotropic agent. The mass of the binder is 0.05% to 0.20% of the total mass of the mixture, the mass of the thixotropic agent is 0.01% to 0.10% of the total mass of the mixture, and the mass of the deionized water is 40% to 60% of the sum of the mass of the mixture and the excipients. The ceramic slurry is formed by uniformly mixing the mixed material with the additive solution.

3. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 2, characterized in that, The ceramic raw material comprises a mixture of component A, component B, and component C; Component A is one or a mixture of more than one of quartz powder, fly ash, waste porcelain powder, and feldspar; Component B is one or a mixture of more than one of kaolin, metakaolin, and montmorillonite; Component C is one or a mixture of one or more of steel slag, limestone, electric furnace ash, dust collector ash, and blast furnace slag.

4. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 2, characterized in that, The mixture comprises the following components by weight percentage: SiO2: 52.0%~63.5%; Al2O3: 9.5%~12.5%; Fe2O3: 5.5%~8.5%; CaO: 8.5%~13.5%; MgO: 0%~1.0%; K2O: 0%~0.3%; Na2O: 0%~0.1%; P2O5: 0%~0.1%; SO3: 0%~0.1%; And the unavoidable impurities in the remaining amount; The sum of the weight percentages of the above components and impurities is 100%; and the loss on ignition of the mixture at 700~800 ℃ is 0%~13%.

5. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 2, characterized in that, The adhesive is one or a mixture of more than one of cross-linked polyacrylic acid resin, polyvinyl alcohol, and polyacrylamide; the thixotropic agent is one or a mixture of more than one of hydroxyethyl methylcellulose and hydroxypropyl methylcellulose.

6. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 1, characterized in that, A porous organic template is immersed in a catalyst precursor suspension for 5-15 minutes, allowing the catalyst precursor to be loaded onto the internal pore surface of the porous organic template, thus obtaining a first intermediate template, comprising: A suspension was prepared by placing the catalyst precursor powder in deionized water and stirring continuously, wherein the amount of the catalyst precursor powder was 10-20 wt% of the deionized water. The porous organic template is immersed in the suspension for 5-15 minutes, then removed and dried at 100-130°C to obtain the first intermediate template.

7. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 1, characterized in that, The catalyst precursor powder is a mixture of copper oxide, basic zinc carbonate, and aluminum hydroxide.

8. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 1, characterized in that, The third intermediate template is sintered at 200~800 °C to obtain a porous ceramic support for in-situ supported catalyst with a porosity greater than 90%, wherein the sintering includes: S61. The third intermediate template is heated from room temperature to the first temperature at a heating rate of 4~5 ℃ / min; S62. The third intermediate template at the first temperature is heated to the second temperature at a heating rate of 3~5 °C / min; S63. Maintain the second temperature for 10-30 minutes. S64. The third intermediate template, which is at the second temperature, is heated to the third temperature at a heating rate of 1~3 °C / min; S65. Maintain the third temperature for 5-10 minutes. S66. Cool the third intermediate template at the third temperature to the fourth temperature at a cooling rate of 5~10 ℃ / min; Wherein, the first temperature is 200℃, the second temperature is 200~250℃, the third temperature is 250~800℃, and the fourth temperature is 200~300℃.

9. The method for preparing an in-situ supported catalyst on a porous ceramic support according to claim 1, characterized in that, The porous organic template is a polymer foam, which includes polyurethane foam and polyvinyl alcohol foam. The pore density of the polymer foam is 30~50 PPI.

10. A porous ceramic support in-situ supported catalyst prepared by the preparation method according to any one of claims 1-9.

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