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CN-121988326-A - CO and NOXFlower-shaped CuCo for synergistic purification2O4Preparation method of spinel catalyst

CN121988326ACN 121988326 ACN121988326 ACN 121988326ACN-121988326-A

Abstract

The invention discloses a preparation method of a flower-shaped CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification. The method comprises the steps of weighing copper salt and cobalt salt according to the mol ratio of Cu/Co=1:2, dissolving in water, adding alkaline solution to adjust the pH value of the mixed solution after ultrasonic stirring uniformly, stirring to be slightly alkaline, transferring to a hydrothermal autoclave for hydrothermal reaction, carrying out suction filtration and drying on a reaction product to obtain a catalyst precursor, and roasting in air to obtain the flower-shaped CuCo 2 O 4 spinel catalyst which has small particle size and is rich in microscopic characteristics of pore channels and structural defects. The catalyst has the advantages of simple process, easy repetition and mass industrialized preparation, has low cost and high catalytic activity, is suitable for the environmental catalysis fields of gas purification, automobile industrial tail gas treatment and the like, and has good industrial application prospect.

Inventors

  • ZOU JIAN
  • LI QIANG
  • CAI BING
  • GU HAIBING
  • YAO CHENGZONG

Assignees

  • 南通醋酸纤维有限公司

Dates

Publication Date
20260508
Application Date
20260205

Claims (14)

  1. 1. A preparation method of a flower-shaped CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification is characterized in that the synergistic optimization of a hydrothermal-roasting process is adopted to realize directional synthesis of the flower-shaped CuCo 2 O 4 spinel catalyst, and the catalytic performance of the flower-shaped CuCo 2 O 4 spinel catalyst is improved by regulating and controlling the morphology and structural defects of the flower-shaped structure of the CuCo 2 O 4 spinel catalyst, so that efficient synergistic removal of CO and NO X is realized.
  2. 2. The preparation method of the flower-shaped CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 1, wherein the hydrothermal process comprises the steps of dissolving copper salt and cobalt salt in a solvent in proportion to form a mixed solution, adding alkaline substances into the mixed solution to adjust pH to be weak alkaline, carrying out hydrothermal reaction on the adjusted solution, separating and drying to obtain a catalyst precursor, and roasting the precursor in air to obtain the flower-shaped CuCo 2 O 4 spinel catalyst.
  3. 3. The method for preparing the flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 2, comprising the steps of: The method comprises the following steps of (1) weighing copper salt and cobalt salt, dissolving the copper salt and the cobalt salt in deionized water to form a mixed solution, and stirring the mixed solution by ultrasonic until the mixed solution is completely dissolved, wherein the copper salt is nitrate, acetate or chloride of copper, and the cobalt salt is nitrate, acetate or chloride of cobalt; adding an alkaline solution into the mixed solution obtained in the step (1), adjusting the pH value of the mixed solution, and stirring the mixed solution until the mixed solution is slightly alkaline; transferring the weakly alkaline solution in the step (2) to a hydrothermal autoclave for hydrothermal reaction, naturally cooling a reaction product, and performing suction filtration and drying to obtain a catalyst precursor; And (4) roasting the catalyst precursor in the step (3) in an air atmosphere, cooling and grinding to obtain the flower-shaped CuCo 2 O 4 spinel catalyst.
  4. 4. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein in step (1), copper salt and cobalt salt are weighed and dissolved in deionized water at a Cu/co=1:2 molar ratio to form a mixed solution.
  5. 5. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the concentration of the alkaline solution in the step (2) is 1 to 3 mol.l -1 .
  6. 6. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the alkaline solution in step (2) is NH 4 HCO 3 , ethanolamine or aqueous ammonia solution.
  7. 7. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the pH of the mixed solution in step (2) is 8.5 to 9.5.
  8. 8. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the hydrothermal reaction temperature in step (3) is 180-220 ℃.
  9. 9. The method for preparing a flower-like CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the hydrothermal reaction time in the step (3) is 26 to 30 hours.
  10. 10. The method for preparing a flower-shaped CuCo 2 O 4 spinel catalyst for CO and NO X synergistic purification according to claim 3, wherein the roasting temperature in the step (4) is 400-500 ℃ and the time is 2-4 hours.
  11. 11. The flower-shaped CuCo 2 O 4 spinel catalyst prepared based on the preparation method of any one of claims 1-10 is characterized in that the flower-shaped structure is a three-dimensional hierarchical structure formed by radially assembling nano sheets with the thickness of 20-50 nm, the overall diameter is 6-9 mu m, and the flower-shaped structure has the microscopic characteristics of small particle size and rich pore channels and structural defects.
  12. 12. Use of a flower-like CuCo 2 O 4 spinel catalyst according to claim 11 for the CO-removal of NO X and CO, wherein the use is to achieve CO-purification of CO and NO X in a gas by catalytic reaction.
  13. 13. The use of a flower-like CuCo 2 O 4 spinel catalyst according to claim 12 for the CO-removal of NO X and CO, characterized in that the use is for the simultaneous removal of CO and NO X in industrial waste gases or automobile exhaust gases.
  14. 14. The use of a flower-like CuCo 2 O 4 spinel catalyst according to claim 12 in the CO-removal of NO X and CO, characterized in that in said use the concentration of NO is 500-1000 ppm, the concentration of CO is 1000-2000 ppm, the concentration of o 2 is 0-5 vol.%, and the space velocity is 20000-60000 l.kg -1 •h -1 .

Description

Preparation method of flower-shaped CuCo 2O4 spinel catalyst for CO and NO X synergistic purification Technical Field The invention belongs to the fields of industrial catalysis, environmental pollution control technology and gas purification, and particularly relates to a preparation method of a flower-shaped CuCo 2O4 spinel catalyst for CO and NO X synergistic purification. Background With the rapid development of social economy and industrial technology, the discharge amount of carbon monoxide (CO) and nitrogen oxides (NO X) in the flue gas is increased, so that serious environmental problems such as acid rain, ozone holes, photochemical smog, greenhouse effect and the like are caused, and the ecological environment and the human health are seriously endangered. At present, the NO X is mainly removed by adopting a Selective Catalytic Reduction (SCR) technology, NH 3 is used as a reducing agent to catalyze and convert the NO to N 2 and H 2 O, and the CO is mainly treated by adopting an oxidation technology to convert the CO into CO 2 at high temperature. In the same system, CO and NO X can be used as a reducing agent and an oxidizing agent, so that the 'waste treatment with waste' is realized, the problems of secondary pollution, high cost and the like are effectively solved, and the environment-friendly and economic benefits are great. For CO and NO X CO-purification reactions, the development of new catalysts is critical to the advancement of catalytic technology processes. The non-noble metal oxide catalyst has shown good application prospect in the field of catalysis, for example, mn, fe, co, cu and other oxides have shown good application prospect in the field of CO and NO X synergistic purification. The catalytic effect of noble metal catalysts can be achieved with two or more transition metal composite oxides, relative to the use of a single metal oxide, due to the synergistic effect between metals, which is a current research hotspot. The spinel metal oxide (AB 2O4) has the characteristics of low price, good stability, adjustable structure and the like, has higher catalytic activity and selectivity in the catalytic reaction process, is beneficial to improving the conversion rate of CO and NO X and the selectivity of N 2、CO2, and reduces the generation of bad byproducts. CuCo 2O4 is expected to become an ideal catalytic material for CO and NO X synergistic purification as a composite metal oxide. However, the non-noble metal oxide catalysts disclosed in chinese patents ZL 20201133228. X and ZL202211606544.3 are mostly limited to bulk or amorphous structures, with specific surface areas typically below 30m 2/g, resulting in insufficient active site exposure, and difficult breakthrough of 80% in NO X conversion and N 2 selectivity at 250 ℃. In addition, studies on pages 119374 of volume 280 of journal 2021, appl. Catal. B-Environ. J.P.is pointed out that traditional collaborative purification techniques still rely heavily on noble metal catalysts such as Pt, ru and Ir, which cost up to 5-10 times that of non-noble metal catalysts, limiting their large-scale industrial application. On the other hand, the appearance and the size of the catalyst greatly influence the catalytic performance of the catalyst. The morphology-controllable synthesis of spinel oxide catalysts has attracted much researchers' interest. However, in the prior art, NO flower-like CuCo 2O4 spinel catalyst has been reported to be applied to CO and NO X synergistic purification. Disclosure of Invention Aiming at the technical problems that the traditional catalyst has low catalytic efficiency, limited economic benefit and the like in purifying single pollutants, and aiming at the problems that the catalyst has low activity, high cost and can not cooperatively purify CO and NO X in the prior art, the first aim of the invention is to provide a preparation method of a flower-shaped CuCo 2O4 spinel catalyst, and the high-efficiency cooperative removal of CO and NO X is realized by regulating and controlling the morphology and structural defects of the CuCo 2O4 spinel catalyst, the second aim of the invention is to provide a flower-shaped CuCo 2O4 spinel catalyst, and the third aim is to provide the application of the flower-shaped CuCo 2O4 spinel catalyst in the cooperative removal of NOx and CO. In order to achieve the first purpose, the invention provides a technical scheme of a preparation method of a flower-shaped CuCo 2O4 spinel catalyst for CO and NO X synergistic purification, which adopts synergistic optimization of a hydrothermal-roasting process to realize directional synthesis of the flower-shaped CuCo 2O4 spinel catalyst, and improves the catalytic performance of the flower-shaped CuCo 2O4 spinel catalyst by regulating and controlling the morphology and structural defects of the flower-shaped structure, so that efficient synergistic removal of CO and NO X is realized. The hydrothermal process comprises the steps of dissolving c