CN-119680590-B - Catalyst for degrading formaldehyde and preparation method and application thereof

Abstract

The invention relates to a formaldehyde degradation catalyst and a preparation method and application thereof, wherein the formaldehyde degradation catalyst comprises a carrier and an active component Pd supported on the carrier, the carrier is CeO 1‑x Cl, wherein 0< x <1, the catalyst has rich oxygen vacancies and Pd sites rich in electrons, the Pd sites can generate more high-activity free radicals, and the catalytic performance of the formaldehyde degradation catalyst at room temperature is obviously improved by fully utilizing the synergistic enhancement effect between the oxygen vacancies and the active sites, so that the catalyst can be widely applied to formaldehyde degradation.

Inventors

• YUAN WENJING
• SUN YUTING
• LIN JIUYANG
• ZHOU CHENLIANG
• ZHANG XINGYU
• ZHENG ZHI
• SUN JIAXUAN
• Jing Fengyang

Assignees

• 中国科学院赣江创新研究院

Dates

Publication Date

20260512

Application Date

20241216

Claims (20)

1. 1. The catalyst for degrading formaldehyde is characterized by comprising a carrier and an active component loaded on the carrier, wherein the active component is Pd, the carrier is CeO 1-x Cl, wherein x is 0< 1, and the loading amount of the active component Pd on the carrier is 4.0-6.0 wt%; The formaldehyde degradation catalyst is prepared by the following method, which comprises the following steps: Mixing chlorpalladium salt with inorganic acid to obtain chlorpalladium salt solution, mixing chlorpalladium salt solution with CeO 2 , drying and grinding to obtain catalyst precursor, and calcining the catalyst precursor in reducing atmosphere to obtain the formaldehyde degradation catalyst.
2. 2. A method for preparing the formaldehyde degradation catalyst according to claim 1, comprising the steps of: Mixing chlorpalladium salt with inorganic acid to obtain chlorpalladium salt solution, mixing chlorpalladium salt solution with CeO 2 , drying and grinding to obtain catalyst precursor, and calcining the catalyst precursor in reducing atmosphere to obtain the formaldehyde degradation catalyst.
3. 3. The method of claim 2, wherein the chloropalladate comprises palladium chloride or ammonium chloropalladate.
4. 4. A method of preparation according to claim 3, wherein the chloropalladate is palladium chloride.
5. 5. The method of claim 2, wherein the inorganic acid comprises any one or a combination of at least two of hydrochloric acid, nitric acid, or carbonic acid.
6. 6. The method according to claim 5, wherein the inorganic acid is hydrochloric acid.
7. 7. The method according to claim 2, wherein the concentration of palladium ions in the solution of the chloropalladium salt is 0.01 to 0.1mol/L.
8. 8. The preparation method of the CeO 2 according to claim 2, wherein the preparation method comprises the steps of roasting and grinding cerium salt in air to obtain CeO 2 .
9. 9. The method of claim 8, wherein the cerium salt comprises any one or a combination of at least two of cerium nitrate, cerium carbonate, cerium sulfate, or cerium acetate.
10. 10. The method of claim 9, wherein the cerium salt is cerium nitrate.
11. 11. The method of claim 8, wherein the firing temperature is 400 ℃ to 500 ℃.
12. 12. The method according to claim 8, wherein the firing rate is 5 ℃ to 10 ℃ per minute.
13. 13. The method of claim 8, wherein the firing time is 2h to 10h.
14. 14. The preparation method according to claim 2, wherein the mass ratio of CeO 2 to the palladium chloride-containing salt is 1 (0.04-0.06).
15. 15. The method of claim 2, wherein the drying temperature is 70 ℃ to 90 ℃.
16. 16. The method of claim 2, wherein the drying time is 12-72 hours.
17. 17. The production method according to claim 2, wherein the reducing atmosphere comprises an argon-hydrogen mixture gas in which the content of hydrogen is 5vol% to 10vol%.
18. 18. The method of claim 2, wherein the calcination temperature is 350 ℃ to 550 ℃.
19. 19. The method according to claim 2, wherein the rate of temperature rise of the calcination is 5 ℃ to 10 ℃ per minute.
20. 20. The method of claim 2, wherein the calcination time is 0.5h to 4h.

Description

Catalyst for degrading formaldehyde and preparation method and application thereof Technical Field The invention relates to the technical field of formaldehyde catalysis, in particular to a catalyst for degrading formaldehyde, a preparation method and application thereof. Background Formaldehyde is a typical contaminant that is widely present in ambient and indoor environments. Prolonged exposure to HCHO, even at low concentrations, can cause serious health hazards to humans, such as allergic dermatitis, eye irritation, pneumonia, and even cancer. Therefore, development of an effective method for removing HCHO is of great importance for improving the surrounding environment. Researchers have studied many strategies for removing HCHO contaminants, mainly physical adsorption, biological treatment, catalytic oxidation, etc. The physical adsorption method has the defects of easy adsorption saturation, difficult desorption and the like. The biological treatment method has the defects of high cost, low efficiency and the like. Compared with the method, the catalytic oxidation method is green, efficient, low in cost and low in energy consumption, and has wide application prospect, wherein the photocatalytic oxidation method and the room-temperature catalytic oxidation method are used for reporting more. The room temperature catalytic oxidation method is a potential HCHO degradation technology, which can fully utilize the ambient temperature as energy supply to degrade HCHO into nontoxic and harmless H 2 O and CO 2, but the technology faces the bottleneck of low catalytic performance in practical application. In order to achieve optimal catalytic activity in the process of HCHO degradation, researchers focus on optimizing the structural design of the catalyst, mainly involving the following two aspects, specifically improving the capability of the catalyst to capture HCHO in the initial and HCHO catalytic degradation stages. Whether the catalyst can generate a large amount of high-activity free radicals is a key to influence the degradation efficiency of HCHO, researchers have focused attention on developing and supporting noble metals (Pd, pt and Au) as room temperature catalytic oxidation catalysts to obtain good activity for the production of active substances. CeO 2 can switch between the two oxidation states of Ce 4+ and Ce 3+, and is often used as a catalyst substrate. The disadvantage is that hydroxyl groups and carbonates and/or carboxylic acids are easily formed on the surface, which makes it difficult to disperse the noble metal particles effectively. Based on the above technical problems, how to develop a formaldehyde catalyst with uniformly dispersed active substances and higher catalyst efficiency and provide a catalyst preparation method with simple preparation method and mass production capability has become a problem to be solved at present. Disclosure of Invention In order to solve the technical problems, the invention aims to provide a catalyst for degrading formaldehyde, a preparation method and application thereof, the catalyst provided by the invention has rich oxygen vacancies and Pd sites rich in electrons, and the Pd sites can generate more high-activity free radicals. By fully utilizing the synergistic enhancement effect between the oxygen vacancy and the active site, the catalytic performance of the catalyst for degrading formaldehyde at room temperature is obviously improved, so that the catalyst can be widely applied to formaldehyde degradation. To achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the invention provides a formaldehyde degradation catalyst, which comprises a carrier and an active component Pd supported on the carrier, wherein the carrier is CeO 1-x Cl, and 0< x <1. The invention constructs an oxygen-enriched vacancy system CeO 1-x Cl/Pd, and oxygen vacancies and Pd sites play an important role in the initial stage and mineralization stage of HCHO degradation respectively. Studies have shown that the presence of chloride ions facilitates the dispersion of the noble metal active sites, and that substitution of the lattice oxygen on CeO 2 by chloride ions converts CeO 2 to CeOCl. The effect of oxygen vacancies is mainly to enrich HCHO in the surrounding environment, and the electron-rich Pd sites interact with O 2 to generate highly active O 2-, thereby further oxidizing HCHO contaminants. The formaldehyde catalyst fully utilizes the synergistic enhancement effect between oxygen vacancies and Pd sites, and improves the formaldehyde degradation efficiency of the catalyst at room temperature. The following preferred technical solutions are used as the present invention, but not as limitations on the technical solutions provided by the present invention, and the technical objects and advantageous effects of the present invention can be better achieved and achieved by the following preferred technical solutions. Preferably, the loading