SiC porous foamed ceramic catalyst carrier for catalytic hydrogen production and preparation method of SiC porous foamed ceramic catalyst carrier

Abstract

The invention discloses a SiC porous foamed ceramic catalyst carrier for catalyzing hydrogen production and a preparation method, and belongs to the field of ceramic materials. The carrier is prepared by taking quartz fine powder and coke fine powder as main raw materials and silicon carbide fine powder and silica sol as additives through a sponge template method. The polymer has a porous foam structure and shows good chemical stability and thermal stability in acidic, alkaline and neutral environments. The preparation method comprises the steps of ceramic slurry preparation, forming treatment, drying, sintering and characterization analysis. The carrier is simple and controllable in preparation process and suitable for large-scale industrial production, and important technical support is provided for development of the hydrogen energy technology.

Description

Technical Field

[0001] The present invention relates to the field of ceramic materials, and particularly to a SiC porous foam ceramic catalyst support for catalytic hydrogen production and a preparation method thereof. This support has a high specific surface area, high porosity, and good chemical stability, and is suitable for efficient catalytic hydrogen production reactions. Background Art

[0002] As a clean and efficient energy source, hydrogen energy is becoming increasingly important. Catalytic hydrogen production technology is the main way for future hydrogen energy supply, and will play a role in important fields such as transportation, industry, and electricity, providing support for the low-carbon transformation of the global energy structure. In this context, to improve the hydrogen production efficiency, the catalytic support in the hydrogen production process has become a research hotspot. Porous silicon carbide foam ceramics, due to their unique physical and chemical properties, show significant advantages as hydrogen production catalyst supports in terms of green, environmental protection, and high-efficiency hydrogen production.

[0003] However, the existing research on porous silicon carbide ceramic catalyst supports usually faces problems such as difficult pore structure control, complex processes, and high preparation costs. This project proposes to use carbon thermal reduction of quartz fine powder combined with the template method to study the preparation of porous silicon carbide ceramic catalyst supports, aiming to solve the challenges in the existing technology, and prepare porous silicon carbide ceramics with a high specific surface area, uniform pore structure, and good mechanical stability by optimizing the raw material ratio, sintering process, and improvement of the template, so as to provide a more efficient catalyst support for catalytic hydrogen production. Applying the product to environmental protection technologies and improving industrial production efficiency, while also providing more possibilities for the application of porous silicon carbide foam ceramics in other fields.

[0004] In summary, an experimental study is proposed to prepare porous silicon carbide foam ceramics by using carbon thermal reduction of quartz fine powder combined with the template method and optimize their performance, providing a support test for catalytic hydrogen production, with the expectation of promoting environmental protection technologies and improving industrial production efficiency. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to provide a catalyst support with a high specific surface area, high porosity, and good chemical stability and a preparation method thereof, so as to solve the problems of short service life and low catalytic efficiency of the existing catalytic hydrogen production catalyst supports.

[0006] To achieve the above purpose, the embodiments of the present invention provide a SiC porous foam ceramic catalyst support for catalytic hydrogen production, which is characterized in that:

[0007] The support has a porous foam structure, with a pore diameter range of 100 nanometers to 1 millimeter; the specific surface area is greater than 100 square meters per gram; the porosity is greater than 70%; it has good chemical stability and can stably exist in acidic, alkaline, and neutral environments; it has high thermal stability and can maintain a stable structure at temperatures above 800°C.

[0008] The described SiC porous foam ceramic catalyst support is characterized in that: the pressure resistance strength of the support is greater than 5 MPa; the specific surface area of the support is between 100 and 200 square meters per gram; the porosity of the support is between 70% and 85%.

[0009] The described SiC porous foam ceramic catalyst support is characterized in that: the surface of the support is loaded with catalyst active components, and the active components are selected from one or more of platinum (Pt), palladium (Pd), and nickel (Ni); the loading amount of the active components is 0.1% to 10% of the mass of the support.

[0010] The described method for preparing an SiC porous foam ceramic catalyst support for catalytic hydrogen production is characterized by including the following steps: (a) using quartz fine powder and coke fine powder as the main raw materials, silicon carbide fine powder and silica sol as additives, adding a plasticizer, and mixing to form a ceramic slurry; (b) injecting the ceramic slurry into sponge molds with different densities, and the pore diameter range of the sponge molds is 35 ppi to 55 ppi; (c) drying the slurry injected into the molds; (d) performing carbon burial treatment on the dried specimen in a crucible, and then sintering it in a high-temperature muffle furnace; (e) performing characterization analysis on the sintered SiC porous foam ceramic.

[0011] The described preparation method is characterized in that: the mass ratio of the quartz fine powder to the coke fine powder is 1.7:1; the concentration of the silica sol is 20%; the plasticizer is one or two of methyl cellulose and dextrin powder, and the addition amount is 5% of the total mass of the raw materials.

[0012] The described drying treatment is natural drying at room temperature or drying at 40°C to 80°C for 12 hours; the sintering process includes the following steps: heating to 1000°C at a rate of 5°C / min to 15°C / min and holding for 1 to 3 hours; heating to 1400°C at a rate of 3°C / min to 7°C / min and holding for 2 to 4 hours; heating to 1500°C to 1700°C at a rate of 2°C / min to 5°C / min and holding for 2 to 4 hours, and then naturally cooling to room temperature.

[0013] The catalyst active components are deposited on the surface of the sintered SiC porous foam ceramic by chemical vapor deposition (CVD) or physical vapor deposition (PVD) methods; the catalyst active components are selected from one or more of platinum (Pt), palladium (Pd), and nickel (Ni).

[0014] The embodiments of the present invention have the following advantages:

[0015] The advantages of the present invention are high temperature resistance, high strength, chemical inertness, low coefficient of thermal expansion, and also have characteristics such as a large specific surface area and controllable and uniform pore sizes. As a catalyst support, the silicon carbide porous foam ceramic can provide more active sites, enhance the catalytic activity, and at the same time, due to its high porosity and excellent heat and mass transfer performance, the catalytic reaction performance is also improved. Detailed Embodiments

[0016] The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0017] Example 1

[0018] Example 1 is a detailed design feature and corresponding efficacy description of a SiC porous foam ceramic catalyst support for catalytic hydrogen production according to the present invention.

[0019] The SiC porous foam ceramic catalyst support according to the present invention is characterized by having a high specific surface area, high porosity, and good chemical stability, and is suitable for efficient catalytic hydrogen production reactions. The support is a porous foam structure, with a pore size range of 100 nanometers to 1 millimeter, a specific surface area greater than 100 square meters per gram, and a porosity greater than 70%, and can stably exist in acidic, alkaline, and neutral environments.

[0020] Preferably, the SiC porous foam ceramic catalyst support has a compressive strength greater than 5 MPa, a specific surface area between 100 and 200 square meters per gram, and a porosity between 70% and 85%. Its efficacy is to significantly increase the number of active sites of the catalyst, thereby improving the catalytic hydrogen production efficiency.

[0021] Preferably, the surface of the support is loaded with catalyst active components, and the active components are selected from one or more of platinum (Pt), palladium (Pd), and nickel (Ni), and the loading amount is 0.1% to 10% of the mass of the support. This design can further enhance the catalytic performance of the support and improve the hydrogen production efficiency.

[0022] Preferably, the preparation method of the support includes the following steps: using quartz fine powder and coke fine powder as the main raw materials, silicon carbide fine powder and silica sol as additives, adding a plasticizer, and mixing to form a ceramic slurry; injecting the slurry into sponge molds with different densities; drying; performing carbon burial treatment in a crucible and then sintering; and performing characterization and analysis on the sintered ceramic. This preparation method is simple and controllable, and is suitable for large-scale industrial production.

[0023] The performance indicators such as the compressive strength, specific surface area, porosity, phase, and microstructure of the SiC porous foam ceramic catalyst support are characterized and analyzed by methods such as a universal testing machine, BET method, XRD, and SEM. The excellent performance of these performance indicators makes the support show high efficiency and stability in the catalytic hydrogen production reaction.

[0024] Example 2

[0025] Example 2 is an explanation of the working principle of the preparation method of the SiC porous foam ceramic catalyst support described in the present invention.

[0026] The SiC porous foam ceramic catalyst support of the present invention uses quartz fine powder and coke fine powder as the main raw materials, and generates SiC through a carbothermal reduction reaction. By adding silicon carbide fine powder and silica sol as additives, the bonding strength and stability of the ceramic can be enhanced. The addition of a plasticizer (such as methyl cellulose or dextrin powder) makes the ceramic slurry have better formability. By using the sponge template method for forming, the design of a porous foam structure can be realized, and the pore size range can be adjusted by the density of the sponge mold. During the sintering process, the ceramic is ensured to be sintered uniformly by gradually increasing the temperature, and finally, SiC porous foam ceramic with a high specific surface area and high porosity is formed.

[0027] The surface of the support is loaded with catalyst active components (such as Pt, Pd, Ni, etc.) by chemical vapor deposition (CVD) or physical vapor deposition (PVD) methods to further enhance its catalytic performance. This design enables the support to efficiently utilize the energy in the environment in the catalytic hydrogen production reaction and achieve a long-term stable hydrogen production effect.

[0028] Example 3

[0029] Example 3 is an explanation of the usage method of the SiC porous foam ceramic catalyst support described in the present invention.

[0030] Before use, the SiC porous foam ceramic catalyst support should be pretreated according to actual requirements. If the support needs to be heated and activated, after loading the catalyst active components on the surface of the sintered support, it should be placed in a hydrogen or argon atmosphere for reduction treatment to improve the catalytic activity of the support.

[0031] In the catalytic hydrogen production reaction, the treated SiC porous foam ceramic catalyst support is placed in a reactor and optimized according to the reaction conditions (such as temperature, pressure, raw material gas, etc.). For example, in the water decomposition reaction, the support can efficiently catalyze the decomposition of water at high temperature to generate hydrogen and oxygen.

[0032] If it is found that the support is damaged or its performance deteriorates during use, it should be immediately stopped and replaced. Regularly conduct performance tests on the support to ensure its high efficiency and stability in the catalytic hydrogen production reaction.

[0033] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A SiC porous foam ceramic catalyst carrier for catalytic hydrogen production, characterized in that: The carrier is a porous foam structure with a pore size ranging from 100 nanometers to 1 millimeter; a specific surface area of ​​100 to 200 square meters per gram; a porosity of 70% to 80%; good chemical stability, with a mass loss of less than 1% after immersion in an environment of pH = 1-14 for 24 hours; high thermal stability, with no structural collapse after being kept at 800°C for 10 hours, and no phase change below 1700°C.

2. The SiC porous foam ceramic catalyst carrier according to claim 1, characterized in that: The compressive strength of the carrier is greater than 5MPa; the specific surface area of ​​the carrier is between 100 and 200 square meters per gram; and the porosity of the carrier is between 70% and 85%.

3. The SiC porous foam ceramic catalyst carrier according to claim 1 or 2, characterized in that: The surface of the carrier is loaded with catalyst active components, and the active components are selected from one or more of platinum (Pt), palladium (Pd), and nickel (Ni); the loading amount of the active components is 0.1% to 10% of the carrier mass.

4. A method for preparing a SiC porous foam ceramic catalyst carrier for catalytic hydrogen production, characterized in that: The following steps are involved: (a) weighing quartz fine powder and coke fine powder in a mass ratio of 1.7:1, adding silicon carbide fine powder (5%-10% of the total mass) and silica sol (concentration 20%), mixing, adding plasticizer (methyl cellulose or dextrin powder, 5%-15% of the total mass), and ball milling to prepare a homogeneous slurry; (b) injecting the ceramic slurry into sponge molds of different densities, wherein the pore size of the sponge mold ranges from 35 ppi to 55 ppi; (c) drying the slurry injected into the mold; (d) subjecting the dried sample to carbon embedding treatment in a crucible, and then sintering in a high-temperature muffle furnace; (e) Characterization and analysis of the sintered SiC porous foam ceramics.

5. The preparation method according to claim 4, characterized in that: The mass ratio of the quartz fine powder to the coke fine powder is 1.7:1; the concentration of the silica sol is 20%; the plasticizer is methyl cellulose, and the added amount thereof is 5% of the total mass of the raw materials.

6. The preparation method according to claim 4 or 5, characterized in that: The drying treatment is natural drying at room temperature or drying at 40°C to 80°C for 12 hours; the sintering process includes the following steps: heating to 1000°C at 5°C / min to 15°C / min, and keeping warm for 1 to 3 hours; heating to 1400°C at 3°C / min to 7°C / min, and keeping warm for 2 to 4 hours; heating to 1500°C to 1700°C at 2°C / min to 5°C / min, and keeping warm for 2 to 4 hours, and then naturally cooling to room temperature.

7. The preparation method according to any one of claims 4 to 6, characterized in that: Catalyst active components are deposited on the surface of the sintered SiC porous foam ceramic by chemical vapor deposition (CVD) or physical vapor deposition (PVD) method; the catalyst active components are selected from one or more of platinum (Pt), palladium (Pd) and nickel (Ni).