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CN-121972190-A - Ru-Zr/CePO for inhibiting polychlorinated byproducts4Catalyst, preparation method and application thereof

CN121972190ACN 121972190 ACN121972190 ACN 121972190ACN-121972190-A

Abstract

The invention belongs to the technical field of environmental catalytic materials, and particularly discloses a Ru-Zr/CePO 4 catalyst for inhibiting polychlorinated byproducts, a preparation method and application thereof. The catalyst comprises a CePO 4 carrier and an active component supported on the surface of the CePO 4 carrier, wherein the active component comprises Zr species and Ru species, and the catalyst has a multiphase interface structure comprising a Ru 0 /CePO 4 interface, a RuO x /CePO 4 interface, a ZrO x /CePO 4 interface and a RuO x -ZrO x /CePO 4 interface. The interface between CePO 4 and ZrO x /CePO 4 promotes the adsorption dechlorination of dichloroethane and the rapid removal of HCl, and the interface between the electron-rich Ru species and RuO x -ZrO x enhances the migration of lattice oxygen and the activation of water, so as to rapidly oxidize and hydrolyze the chloroethylene intermediate at low temperature. The multi-interface synergy blocks Cl 2 circulation from the source and inhibits polychlorinated byproducts. The catalyst has the characteristics that the T 90 reaches 260 ℃ at 260 ℃, the selectivity of CO 2 is close to a theoretical value, and the catalyst has excellent water resistance, chlorine poisoning resistance and long-term stability, and has wide application prospect.

Inventors

  • WANG WEI
  • JIANG XU
  • QIAN MIN
  • HE YUANJUN
  • MIAO JIATONG
  • XU KE

Assignees

  • 常州大学

Dates

Publication Date
20260505
Application Date
20260331

Claims (10)

  1. 1. The Ru-Zr/CePO 4 catalyst for inhibiting polychlorinated byproducts is characterized by comprising a CePO 4 carrier and an active component supported on the surface of the CePO 4 carrier, wherein the active component comprises Zr species and/or Ru species, and the catalyst has a multiphase interface structure comprising a Ru 0 /CePO 4 interface, a RuO x /CePO 4 interface, a ZrO x /CePO 4 interface and a RuO x -ZrO x /CePO 4 interface.
  2. 2. The Ru-Zr/CePO 4 catalyst according to claim 1, wherein the mass fraction of Zr species is 5-20 wt% and the mass fraction of Ru species is 0.5-2 wt% based on the mass of the CePO 4 support.
  3. 3. The Ru-Zr/CePO 4 catalyst according to claim 2, wherein the mass fraction of Zr species is 15wt% and the mass fraction of Ru species is 1 wt%.
  4. 4. The Ru-Zr/CePO 4 catalyst according to claim 1, wherein said CePO 4 support has a hexagonal phase crystal structure, wherein said Zr species is dispersed as amorphous ZrO x nanoclusters in a monolayer on the surface of the CePO 4 support, wherein said Ru species is present in part as single crystal Ru 0 nanoclusters exposing {001} crystal planes, and is incorporated in part into the matrix of said amorphous ZrO x nanoclusters to form a Ru-O-Zr bridging structure.
  5. 5. A process for preparing a Ru-Zr/CePO 4 catalyst according to any one of claims 1 to 4, characterized in that it is prepared by a step-by-step sequential impregnation method, comprising the following steps: (1) Preparing a CePO 4 carrier, namely mixing cerium salt aqueous solution and phosphate aqueous solution by adopting a coprecipitation method, and obtaining the CePO 4 carrier after stirring, ageing, washing, drying and roasting; (2) Preparing a Zr/CePO 4 precursor, namely soaking the CePO 4 carrier obtained in the step (1) in a zirconium-containing precursor solution by adopting an isovolumetric impregnation method, and drying and roasting to obtain the Zr/CePO 4 precursor; (3) The preparation of the Ru-Zr/CePO 4 composite catalyst comprises the steps of dipping the Zr/CePO 4 precursor obtained in the step (2) into a ruthenium-containing precursor solution by adopting an equal volume dipping method, and drying and roasting the Ru-Zr/CePO 4 composite catalyst.
  6. 6. The preparation method according to claim 5, wherein in the step (1), the cerium salt is cerium nitrate hexahydrate, the phosphate is ammonium phosphate, the stirring time is 0.2-2 h, the aging time is 10-24 h, the drying temperature is 60-120 ℃, and the roasting condition is that roasting is carried out in static air at 350-600 ℃ for 2-4 h.
  7. 7. The preparation method of the zirconium-containing precursor according to claim 5, wherein in the step (2), the zirconium-containing precursor solution is an aqueous solution of zirconyl nitrate, the Zr loading amount is 5-20wt% based on the mass of the CePO 4 carrier, the drying temperature is 60-100 ℃, the drying time is 10-15 h, and the roasting condition is that the zirconium-containing precursor solution is roasted in static air at 350-550 ℃ for 2-4 h.
  8. 8. The preparation method of the catalyst according to claim 5, wherein in the step (3), the ruthenium-containing precursor solution is a ruthenium trichloride aqueous solution, the Ru loading amount is 0.5-2 wt% based on the mass of the CePO 4 carrier, the drying temperature is 60-100 ℃, the drying time is 10-15 h, and the roasting condition is that the catalyst is roasted in static air at 350-550 ℃ for 2-4 h.
  9. 9. Use of a Ru-Zr/CePO 4 catalyst as claimed in any one of claims 1 to 4 in catalytic combustion of chlorine-containing volatile organic compounds.
  10. 10. The use according to claim 9, wherein the chlorine-containing volatile organic compound is 1, 2-dichloroethane, and wherein the catalyst promotes the adsorption and dehydrochlorination of 1, 2-dichloroethane by using the acid-base sites of the CePO 4 and ZrO x /CePO 4 interface in the process of catalytic oxidation of 1, 2-dichloroethane, and rapidly captures, hydrolyzes and oxidizes at low temperature the vinyl chloride intermediate produced by the dehydrochlorination by using the RuO x -ZrO x /CePO 4 interface, thereby inhibiting the formation of vinyl chloride and polychlorinated byproducts.

Description

Ru-Zr/CePO 4 catalyst for inhibiting polychlorinated byproducts and preparation method and application thereof Technical Field The invention relates to the technical field of environmental catalytic materials, in particular to a Ru-Zr/CePO 4 catalyst for inhibiting polychlorinated byproducts, a preparation method and application thereof. Background Chlorinated volatile organic compounds, such as 1, 2-dichloroethane, vinyl chloride, etc., are a typical type of toxic and harmful air pollutants, and have high toxicity, strong chemical stability and potential carcinogenicity. It is widely used as an industrial solvent, a cleaning agent and a chemical intermediate, resulting in serious environmental pollution problems. Among many treatment technologies, the catalytic oxidation method is considered to be one of the most promising technologies for removing CVOCs because of the advantages of low operating temperature, low energy consumption, less secondary pollution and the like, and the core of the catalytic oxidation method is to develop a high-performance catalyst. Currently, catalysts for CVOCs catalytic oxidation mainly include transition metal oxides, molecular sieves, and the like. The transition metal oxide with oxidation-reduction activity (such as CeO 2、Co3O4、MnO2 and the like) has stronger oxygen activating capability and high lattice oxygen mobility, and can promote the deep oxidation of CVOCs. However, the Lewis acid sites and oxygen vacancies of such catalysts tend to strongly adsorb chlorine species during the reaction, resulting in catalyst chloridiosis/deactivation. In addition, the high redox activity can exacerbate the Deacon reaction to generate a large amount of Cl 2, and the Cl 2 can be used as a chlorinating agent to react with a reaction intermediate (such as VC) in an electrophilic addition or substitution reaction on M-Cl or M-OCl sites on the surface, so that polychlorinated byproducts with stronger toxicity are generated, and secondary pollution is caused. On the other hand, acidic transition metal oxides (such as WO x、MoOx、VOx) or H-type zeolite, although possessing abundant strong Lewis acid and bransted acid sites, can effectively catalyze DCE dehydrochlorination to produce HCl and VC, thereby alleviating the chlorine poisoning, but the inherent weak oxidation-reduction performance seriously hinders the deep oxidation of dechlorinated intermediates such as VC, and the like, so that these harmful intermediates accumulate in the reaction system, and limit the practical application thereof. Cerium phosphate is used as an emerging catalytic material, and the surface of the cerium phosphate has a unique 'acid-base pair' structure and consists of a Ce 3+ Lewis acid site and a PO 43- nucleophilic alkaline site. The Ce 3+ site is responsible for adsorbing CVOCs molecules and breaking C-Cl bonds, and the PO 43- group promotes desorption of HCl, so that surface chlorine accumulation and poisoning can be effectively relieved. Meanwhile, the CePO 4 has stable crystal structure and high P-O bond strength, can maintain structural integrity in high-temperature, chlorine-rich and steam environments, and has long-acting catalytic durability. However, similar to acidic oxides, the relatively weak redox capacity of CePO 4 limits the deep oxidation efficiency of the reaction intermediates (especially dehydrochlorination product VC). Therefore, how to construct a catalyst with high-efficiency dechlorination capability and excellent deep oxidation activity on the basis of CePO 4 material and fundamentally inhibit the generation of toxic byproducts becomes a key technical problem to be solved in the current CVOCs catalytic purification field. Disclosure of Invention Aiming at the technical problem that the catalyst in the prior art can not fundamentally inhibit the generation of toxic byproducts, the invention provides a Ru-Zr/CePO 4 catalyst for inhibiting polychlorinated byproducts, and a preparation method and application thereof. The catalyst comprises a CePO 4 carrier and an active component supported on the surface of the CePO 4 carrier, wherein the active component comprises Zr species and/or Ru species, and the catalyst has a multiphase interface structure comprising a Ru 0/CePO4 interface, a RuO x/CePO4 interface, a ZrO x/CePO4 interface and a RuO x-ZrOx/CePO4 interface, wherein x is less than or equal to 2. Further, the mass fraction of the Zr species is 5-20 wt% (preferably 15-wt%) based on the mass of the CePO 4 carrier. Further, the mass fraction of the Ru species is 0.5-2 wt% (preferably 1 wt%) based on the mass of the CePO 4 carrier. Further, the CePO 4 carrier is of a hexagonal phase crystal structure, the Zr species is dispersed on the surface of the CePO 4 carrier in a single-layer mode in the form of amorphous ZrO x nano clusters, part of the Ru species exists in the form of single-crystal Ru 0 nano clusters exposing {001} crystal faces, and part of the Ru species is doped into a matrix o