CN-121988329-A - Nanometer cerium oxide/tourmaline composite catalyst and preparation method and application thereof

Abstract

The invention relates to a nano cerium oxide/tourmaline composite catalyst and a preparation method and application thereof, wherein the nano cerium oxide/tourmaline composite catalyst comprises tourmaline and nano cerium oxide loaded on the surface of the tourmaline, the appearance of the nano cerium oxide/tourmaline composite catalyst is in a rod-shaped structure, the average length of the rod-shaped structure is 150-300 nm, and the average diameter of the rod-shaped structure is 15-20 nm. According to the invention, the polarization characteristic of the tourmaline is utilized to cooperate with the cerium oxide to construct a CeO 2 /tourmaline composite catalytic system, so that the complementary advantages of CeO 2 and the tourmaline are realized, the cerium oxide is loaded on the tourmaline through an in-situ hydrothermal growth process, and the catalyst obtained through the hydrothermal reaction has a rod-shaped morphology, does not need high-temperature calcination, and has better crystallinity, smaller size and finer size. The obtained nano cerium oxide/tourmaline composite catalyst improves the catalytic degradation efficiency of CO and improves the high temperature and long-time stability of the cerium-based catalyst.

Inventors

• WANG QI
• WANG ZHEN
• SHEN GENLI
• LIU MI
• GONG YAN

Assignees

• 国家纳米科学中心

Dates

Publication Date

20260508

Application Date

20260327

Claims (10)

1. 1. The nano cerium oxide/tourmaline composite catalyst is characterized by comprising tourmaline and nano cerium oxide loaded on the surface of the tourmaline; The morphology of the nano cerium oxide/tourmaline composite catalyst is a rod-shaped structure; the average length of the rod-shaped structure is 150nm-300nm, and the average diameter is 15-20nm.
2. 2. The nano cerium oxide/tourmaline composite catalyst according to claim 1, wherein the mass ratio of the nano cerium oxide to the tourmaline in the nano cerium oxide/tourmaline composite catalyst is 1 (0.25-4).
3. 3. A method for preparing the nano cerium oxide/tourmaline composite catalyst according to claim 1 or 2, wherein the method comprises the steps of: Mixing cerium source, tourmaline and solvent to obtain reaction solution; Mixing the reaction solution and the precipitant, and sequentially carrying out stirring reaction and hydrothermal reaction to obtain the nano cerium oxide/tourmaline composite catalyst.
4. 4. The method according to claim 3, wherein the concentration of the cerium source in the reaction solution is 0.1mol/L to 0.4mol/L.
5. 5. The method according to claim 3 or 4, wherein the precipitant comprises any one or a combination of at least two of ammonia water, potassium hydroxide or sodium hydroxide; And/or the concentration of the precipitant is 4mol/L-6mol/L.
6. 6. The method of any one of claims 3 to 5, wherein the cerium source comprises any one or a combination of at least two of cerium nitrate, cerium chloride, or cerium sulfate; and/or the tourmaline comprises any one or a combination of at least two of ferroelectric stone, magnesium tourmaline or lithium tourmaline; and/or the solvent comprises water.
7. 7. The method according to any one of claims 3 to 6, wherein the pH during the stirring reaction is 8 to 12; And/or the stirring reaction time is 1h-5h.
8. 8. The method of any one of claims 3-7, wherein the hydrothermal reaction is at a temperature of 110 ℃ to 150 ℃; And/or the hydrothermal reaction time is 18-30 h; and/or after the hydrothermal reaction, solid-liquid separation and drying are further included before the nano cerium oxide/tourmaline composite catalyst is obtained.
9. 9. The preparation method according to any one of claims 3 to 8, characterized in that the preparation method comprises the steps of: (1) According to the mass ratio of nano cerium oxide to tourmaline in the prepared composite catalyst of 1 (0.25-4), dissolving a cerium source and tourmaline in water to obtain a reaction solution, wherein the concentration of the cerium source is 0.1mol/L-0.4mol/L; (2) Mixing the reaction solution and a precipitator with the concentration of 4mol/L-6mol/L, regulating the pH value to 8-12, stirring and reacting for 1-5 h, performing hydrothermal reaction for 18-30 h at 110-150 ℃, centrifuging and drying the product to obtain the nano cerium oxide/tourmaline composite catalyst.
10. 10. Use of the nano cerium oxide/tourmaline composite catalyst according to claim 1 or 2, wherein the nano cerium oxide/tourmaline composite catalyst is used for catalytic oxidation of carbon monoxide.

Description

Nanometer cerium oxide/tourmaline composite catalyst and preparation method and application thereof Technical Field The invention relates to the technical field of nano material preparation, in particular to a nano cerium oxide/tourmaline composite catalyst and a preparation method and application thereof. Background With the rapid development of the global industry, CO generated by incomplete combustion of fossil fuels and industrial flue gas has become one of the main sources of atmospheric pollution, and meanwhile, certain harm is caused to human health, such as acute poisoning of the body, chronic injury of organs such as heart and lung, central nervous system and the like. Common CO treatment technologies include a direct combustion method, a cryogenic separation method, a solution absorption method, an adsorption separation method, a catalytic oxidation method and the like, wherein the catalytic oxidation method is widely applied due to the advantages of high efficiency, simple operation, low energy consumption and the like. Although noble metal catalysts such as Pt and Pd exhibit excellent catalytic activity, their use is limited by the disadvantages of high cost, easy deactivation, etc. The CO catalytic oxidation reaction is used as a 'model reaction' in the heterogeneous catalysis field, is an important carrier for exploring the nature of the catalytic action, has irreplaceable practical application value in the fields of environmental protection, energy conversion and the like, and has urgent demands on efficient CO oxidation catalysts in key scenes such as automobile tail gas purification, industrial waste gas treatment, fuel cell hydrogen energy purification and the like. Cerium oxide (CeO 2) is taken as a typical rare earth oxide, has excellent oxygen storage and oxygen release capacity by virtue of unique Ce 4+/Ce3+ valence state circulation characteristics, and meanwhile, oxygen vacancy defects are easy to form in the crystal structure, so that the cerium oxide becomes a core carrier material in the field of CO catalytic oxidation and is widely applied to various catalytic systems. Although CeO 2 has remarkable advantages, the catalyst has a plurality of inherent defects, which restrict the application of the catalyst in actual scenes (1) the low-temperature activity is insufficient, the requirements of low-temperature scenes such as tail gas purification in the cold start stage of a motor vehicle are difficult to meet, (2) the high-temperature stability is poor, the CeO 2 is easy to generate phenomena such as grain sintering, the specific surface area is reduced in the long-term high-temperature reaction process, the concentration of oxygen vacancies is reduced, the catalytic activity is fast attenuated, the stability of the oxygen vacancies is poor, the oxygen vacancies on the surface of CeO 2 are easy to generate agglomeration or are occupied by impurity species, and the catalyst cannot continuously and stably participate in the catalytic reaction. Based on the above problems, most of the existing researches focus on optimizing the microstructure and chemical components of CeO 2, and the catalytic performance is improved by regulating the number and distribution of active sites, so that the regulation and control effect of the intrinsic physical field (such as polarized electric field) existing in the material body on catalytic reaction is ignored. The essence of the catalytic reaction is the charge transfer and the breaking-forming process of chemical bonds, and the intrinsic physical field can fundamentally optimize the catalytic performance by directionally regulating and controlling charge distribution, changing the physical adsorption configuration of the reaction, reducing the reaction energy barrier and the like. Therefore, how to improve the low-temperature activity, the high-temperature stability and the oxygen vacancy stability of the cerium-based catalyst and the preparation method thereof to realize the high-efficiency catalytic oxidation of CO becomes a technical problem to be solved in the present. Disclosure of Invention In order to solve the technical problems, the invention aims to provide the nano cerium oxide/tourmaline composite catalyst, and the preparation method and the application thereof. To achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the invention provides a nano cerium oxide/tourmaline composite catalyst which comprises tourmaline and nano cerium oxide loaded on the surface of the tourmaline, wherein the nano cerium oxide/tourmaline composite catalyst has a rod-shaped structure; The average length of the rod-like structure is 150nm to 300nm, and may be, for example, 150nm, 180nm, 200nm, 220nm, 250nm, 280nm or 300nm, but is not limited to the values recited, and other values not recited in the numerical range are equally applicable. The average diameter of the rod-like structure may be, for example, 15nm to 20nm, an