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CN-122006698-A - Manganese cerium oxide catalyst with controllable pore structure, and preparation method and application thereof

CN122006698ACN 122006698 ACN122006698 ACN 122006698ACN-122006698-A

Abstract

The invention discloses a manganese cerium oxide catalyst with a controllable pore channel structure, a preparation method and application thereof, belonging to the technical field of catalyst preparation and environmental catalysis, wherein the preparation method comprises the following steps of 1) preparing a polymethyl methacrylate colloidal crystal template; 2) Mn (NO 3 ) 2 aqueous solution, ce (NO) 3 ·6H 2 O and citric acid are dissolved in a mixed solution of ethylene glycol and methanol to form a manganese cerium precursor solution, 3) polymethyl methacrylate colloidal templates are immersed in the manganese cerium precursor solution and then subjected to suction filtration treatment to obtain a product, and 4) the product is dried and roasted at multiple steps of temperature to obtain the three-dimensional ordered macroporous manganese cerium catalyst. The invention prepares the manganese cerium catalyst with a three-dimensional ordered macroporous structure by using a gel crystal template method, has uniform pore diameter, ordered pore canal and high specific surface area, is convenient for mass transfer and touching active sites, shows excellent toluene catalytic oxidation activity, stability and water resistance, and has good application prospect.

Inventors

  • JIANG YE
  • CHENG SIYUAN
  • ZHANG GUOMENG
  • LIU YANAN
  • SUN XIN
  • SONG JIAYAO

Assignees

  • 中国石油大学(华东)

Dates

Publication Date
20260512
Application Date
20251126

Claims (10)

  1. 1. A preparation method of a manganese cerium oxide catalyst with a controllable pore structure is characterized by comprising the following steps of, Mixing methyl methacrylate and deionized water, heating and stirring in a water bath under the condition of nitrogen, adding a preheated initiator solution into the mixture for free radical polymerization reaction, cooling after the reaction is finished, and sequentially centrifuging and drying to obtain a polymethyl methacrylate template; Ce (NO 3 ) 3 ·6H 2 O and Mn (NO 3 ) 2 and complexing agent are fully dissolved in the mixed solution of methanol and ethylene glycol to obtain manganese cerium precursor solution; Under the vacuum condition, dipping a polymethyl methacrylate template into a manganese cerium precursor solution, and carrying out suction filtration to obtain a MnCe@PMMA precursor material; Drying the MnCe@PMMA precursor material in an oven, and then carrying out multi-stage roasting treatment in a tube furnace to obtain the manganese cerium oxide catalyst with a controllable pore channel structure.
  2. 2. The method for preparing the manganese cerium oxide catalyst with the controllable pore canal structure according to claim 1, wherein the initiator is potassium persulfate, the mass concentration of the initiator solution is 0.5-1%, and the volume ratio of the methyl methacrylate, the deionized water and the initiator solution is 1-1.5:10-15:0.15-0.4.
  3. 3. The method for preparing the manganese cerium oxide catalyst with the controllable pore canal structure according to claim 2, wherein the heating temperature of water bath heating and stirring under the nitrogen condition is 50-80 ℃, the stirring rotating speed is 200-400 rpm, and the free radical polymerization reaction time is 30-60 min.
  4. 4. The method for preparing a manganese cerium oxide catalyst with a controllable pore structure according to claim 1, wherein the ratio of Ce (NO 3 ) 3 ·6H 2 O to Mn (NO 3 ) 2 ) is 0.01-0.03 mol, and the ratio of the amounts of the substances is 0.2-1.
  5. 5. The method for preparing a manganese cerium oxide catalyst with a controllable pore canal structure according to claim 1, wherein the complexing agent is citric acid.
  6. 6. The method for preparing a manganese-cerium oxide catalyst with a controllable pore structure according to claim 5, wherein the total molar ratio of citric acid to metal ions in the manganese-cerium precursor solution is 1:1-1.2.
  7. 7. The method for preparing a manganese-cerium oxide catalyst with a controllable pore structure according to claim 5, wherein the volume ratio of methanol to glycol in the manganese-cerium precursor solution is 0.4-1:1, and the concentration of metal ions is 1-2 mol/L.
  8. 8. The method for preparing a manganese-cerium oxide catalyst with controllable pore channel structure according to claim 5, wherein the multi-stage calcination treatment is a two-stage calcination treatment, The first stage of calcination treatment is to raise the temperature from room temperature to 300-350 ℃ under the condition of air/N 2 atmosphere, the temperature raising rate is 1-5 ℃ per minute, and the temperature is lowered to the room temperature after maintaining for 2-5 hours; And the second stage of calcination treatment is to raise the temperature from room temperature to 400-550 ℃ under the air atmosphere condition, the temperature raising rate is 1-5 ℃ per minute, and the temperature is lowered to the room temperature after maintaining for 2-5 hours.
  9. 9. The manganese cerium oxide catalyst prepared by the preparation method according to any one of claims 1 to 8.
  10. 10. Use of the manganese cerium oxide catalyst according to claim 9 in the catalytic oxidation of toluene.

Description

Manganese cerium oxide catalyst with controllable pore structure, and preparation method and application thereof Technical Field The invention belongs to the technical field of catalyst preparation and environmental catalysis, and particularly relates to a manganese cerium oxide catalyst with a controllable pore channel structure, and a preparation method and application thereof. Background Volatile Organic Compounds (VOCs) are important precursors for fine particulate matter (PM 2.5) and ozone (O 3), are key factors for air pollution and climate change, and pose a serious threat to human health and the environment. The main sources of VOCs include human activity and industrial emissions. Among these VOCs, toluene is often studied as a typical contaminant due to its toxicity, mutagenicity, and other characteristics. The catalytic oxidation technology has the advantages of high efficiency and low energy consumption, and is one of the most feasible VOCs removal technologies at present. The core of the catalytic oxidation technology is to develop a high-efficiency catalyst. The MnCe composite oxide catalyst is widely applied to the catalytic oxidation of VOCs due to the excellent oxidation-reduction performance and the good oxygen storage and release capacity. However, conventional catalysts generally have disordered channels and large mass transfer resistance, which makes it difficult for active sites to sufficiently contact reactants, and easily cause deep reactions of product molecules, thereby forming carbon deposition and reducing catalytic activity. In addition, the high specific surface area of the 3DOM can provide more oxygen adsorption active sites, increase the concentration of oxygen adsorption species on the surface and improve the low-temperature oxidation-reduction property, thereby remarkably improving the catalytic activity. However, how to precisely control the pore size, distribution and pore channel order of the 3DOM catalyst is a great challenge, and the current preparation method is difficult to realize precise regulation and control of the pore size, which often results in wider pore size distribution and poor pore channel order. This can affect the mass transfer efficiency of the catalyst and the exposure of the active sites, reducing the performance of the catalyst. For example, when a nano casting method is used for preparing a 3DOM catalyst, the interaction between a template and a precursor is difficult to control accurately, so that the prepared catalyst has different pore sizes, and pore channels are bent, blocked and the like, so that the diffusion of reactants and products is seriously influenced, and the catalytic activity is reduced. Disclosure of Invention This section is intended to outline some aspects of embodiments of the application and to briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section as well as in the description of the application and in the title of the application, which may not be used to limit the scope of the application. The present invention has been made in view of the above and/or problems occurring in the prior art. Therefore, the invention aims to overcome the defects in the prior art and provide a preparation method of the manganese cerium oxide catalyst with a controllable pore channel structure. In order to solve the technical problems, the invention provides the following technical proposal that comprises, Mixing methyl methacrylate and deionized water, heating and stirring in a water bath under the condition of nitrogen, adding a preheated initiator solution into the mixture for free radical polymerization reaction, cooling after the reaction is finished, and sequentially centrifuging and drying to obtain a polymethyl methacrylate template; Ce (NO 3)3·6H2 O and Mn (NO 3)2 and complexing agent are fully dissolved in the mixed solution of methanol and ethylene glycol to obtain manganese cerium precursor solution; Under the vacuum condition, dipping a polymethyl methacrylate template into a manganese cerium precursor solution, and carrying out suction filtration to obtain a MnCe@PMMA precursor material; Drying the MnCe@PMMA precursor material in an oven, and then carrying out multi-stage roasting treatment in a tube furnace to obtain the manganese cerium oxide catalyst with a controllable pore channel structure. As a preferable scheme of the preparation method of the manganese cerium oxide catalyst with the controllable pore channel structure, the preparation method comprises the steps that the initiator is potassium persulfate, the mass concentration of an initiator solution is 0.5-1%, and the volume ratio of methyl methacrylate, deionized water and the initiator solution is 1-1.5:10-15:0.15-0.4. The preparation method of the manganese cerium oxide catalyst with the controllable pore channel structure is characterized in that the heating temperature of water bath heating and stirring under the n