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CN-121988307-A - ZrO (ZrO-like grain)2/TiO2Solid acid catalyst, preparation method and application thereof

CN121988307ACN 121988307 ACN121988307 ACN 121988307ACN-121988307-A

Abstract

The invention discloses a ZrO 2 /TiO 2 solid acid catalyst and a preparation method and application thereof, and relates to the technical field of catalysts. The catalyst provided by the invention has the advantages that ZrO 2 serving as an active ingredient is attached to the TiO 2 carrier, a Lewis acid structure can be formed, the catalyst has excellent electron withdrawing property, and the solidified silicon rubber in the insulator umbrella cover can be directionally converted into DMC (dimethyl cyclosiloxane mixture) with low molecular weight by activating the solidified silicon rubber in a mode of coordinating with Si-O bonds in the silicon rubber. The catalyst is adopted to catalyze and degrade the silicon rubber umbrella cover in the retired insulator, the conversion rate of reactants can be over 72 percent at the low temperature below 200 ℃, the yield of DMC monomers in the product can be over 75 percent, and the low-temperature high-value recovery of the silicon rubber umbrella cover in the retired composite insulator can be realized.

Inventors

  • WU JIEHUI
  • WANG CHUNJIE
  • PENG XIANGYANG
  • XI RONGJUN
  • CHEN ZHENGYONG
  • ZHENG XIAOGUANG
  • LIU LIN
  • FAN YAZHOU
  • LIN GUOHAI
  • LI JUNCAI

Assignees

  • 广东电网有限责任公司电力科学研究院
  • 广东电网有限责任公司汕尾供电局

Dates

Publication Date
20260508
Application Date
20260402

Claims (10)

  1. 1. The ZrO 2 /TiO 2 solid acid catalyst is characterized by comprising a carrier and an active ingredient supported on the carrier, wherein the carrier comprises TiO 2 , the active ingredient comprises ZrO 2 , and the loading of the active ingredient on the carrier is 55-65 wt%.
  2. 2. The ZrO 2 /TiO 2 solid acid catalyst according to claim 1 wherein the phase of TiO 2 is anatase; and/or, the phase state of the ZrO 2 comprises a monoclinic phase and a tetragonal phase, wherein the content of the monoclinic phase is 90wt% to 95wt% and the content of the tetragonal phase is 5wt% to 10wt%.
  3. 3. The ZrO 2 /TiO 2 solid acid catalyst according to claim 1 or 2, wherein the TiO 2 is rod-like and has an aspect ratio of 5 to 15; and/or, the ZrO 2 is spherical and has a particle size of 10-20 nm.
  4. 4. A process for preparing a ZrO 2 /TiO 2 solid acid catalyst as claimed in any one of claims 1 to 3, characterized by comprising the steps of: Mixing TiO 2 and ZrO 2 under the condition of solution, stirring for loading, and removing the solvent.
  5. 5. The method for preparing a solid acid catalyst for ZrO 2 /TiO 2 according to claim 4, wherein the method for preparing TiO 2 comprises the steps of: Dissolving Ti source in water at pH 4-5 to obtain Ti source solution, adding ammonia water dropwise to obtain precipitate until pH of supernatant is 6-8, separating solid from liquid to obtain precipitate, drying, and calcining.
  6. 6. The method for preparing a solid acid catalyst for ZrO 2 /TiO 2 as claimed in claim 4, wherein the method for preparing ZrO 2 comprises the steps of: Dissolving Zr source in water at pH 4-5 to obtain Zr source solution, adding ammonia water dropwise to obtain precipitate until pH of supernatant is 6-8, separating solid from liquid to obtain precipitate, drying, and calcining.
  7. 7. The process for preparing a solid acid catalyst of ZrO 2 /TiO 2 or 6, wherein, In the preparation method of the TiO 2 , the calcination is carried out in an air atmosphere, the calcination temperature is 600-800 ℃ and the calcination time is 6-10 h; In the preparation method of the ZrO 2 , the calcination is carried out in an air atmosphere, the calcination temperature is 600-800 ℃ and the calcination time is 6-10 h.
  8. 8. Use of a ZrO 2 /TiO 2 solid acid catalyst according to any one of claims 1 to 3 for the catalytic degradation of cured silicone rubber.
  9. 9. A method for catalytic degradation of cured silicone rubber, comprising the steps of: Dissolving the cured silicone rubber by adopting an organic solvent, separating solid from liquid to obtain a silicone rubber solution, and then adding the ZrO 2 /TiO 2 solid acid catalyst according to any one of claims 1-3 to react at 20-30 ℃ for 8-12 h.
  10. 10. The method of catalytically degrading cured silicone rubber of claim 9, wherein the organic solvent comprises at least one of methanol, hexane, and diethylamine.

Description

ZrO 2/TiO2 solid acid catalyst and preparation method and application thereof Technical Field The invention relates to the technical field of catalysts, in particular to a ZrO 2/TiO2 solid acid catalyst and a preparation method and application thereof. Background The composite insulator is widely applied to a power transmission line of a power system due to the excellent anti-pollution flashover performance, however, the design service life of the composite insulator is only 15-20 years, and the composite insulator needs to be retired after the service life is reached, so that the problem of retired recovery is increasingly remarkable along with the increase of the service life of the composite insulator. The composite insulator consists of a silicone rubber umbrella cover, an epoxy glass fiber core rod and two ends of a metal connecting assembly. The core material of the silicone rubber umbrella cover is high-temperature vulcanized silicone rubber (HTV), which is a key structure for realizing an insulation function, and the preparation raw materials of the silicone rubber umbrella cover comprise a series of auxiliary materials such as a coupling agent, a coloring agent, a cross-linking agent, a vulcanizing agent and the like besides the HTV. As one of the effective recovery means for recycling the silicone rubber umbrella cover material in the retired composite insulator, the chemical cracking method is a popular recovery strategy because HTV can be decomposed into a series of dimethyl cyclosiloxanes (DMC) under specific conditions and the filler in the umbrella cover can be separated at the same time. Chemical cracking processes include thermal cracking and catalytic cracking. The thermal cracking method usually needs high temperature above 500 ℃ to crack the silicon rubber into annular DMC small molecules, the high-temperature cracking process has strong randomness, and the DMC selectivity in the product is low. In contrast, the catalytic cracking method can realize the cracking of the silicone rubber umbrella cover at low temperature, and even can realize the cracking work of the silicone rubber at room temperature if the catalyst is designed properly. Meanwhile, through designing the catalyst, the molecular chain of the silicon rubber can be broken at a specific position, and the DMC selectivity in the product is improved. However, catalysts which have a good cracking effect on silicone rubber at low temperatures and can obtain high DMC selectivity have not been reported yet. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a ZrO 2/TiO2 solid acid catalyst, and a preparation method and application thereof. The above object of the present invention is achieved by the following technical scheme: A ZrO 2/TiO2 solid acid catalyst comprises a carrier and an active component supported on the carrier, wherein the carrier comprises TiO 2, the active component comprises ZrO 2, and the loading of the active component on the carrier is 55-65 wt%. The solid acid catalyst provided by the application is of a supported structure, zrO 2 is used as an active ingredient to be attached to a TiO 2 carrier, and a Lewis acid structure with strong electric shortage can be formed based on the high charge/radius ratio and the empty orbit characteristics of Zr 4+ and Ti 4+, so that the catalyst has excellent electron withdrawing characteristics. Based on the above, when the catalyst is used for catalyzing and degrading the cured silicone rubber, lewis acidic sites can attack Si-O-Si molecular chains rich in electrons in the silicone rubber chains, and the Si-O bonds are strongly polarized in a coordination mode, so that potential barriers for bond breaking are remarkably reduced, and the degradation of the silicone rubber is promoted. Among them, tiO 2 tends to promote cleavage of terminal Si-O bonds, favoring the creation of Si-O-H terminals, while ZrO 2 tends to drive rearrangement of the silicon cation intermediate, forming D4-D6 cyclic oligomers. By combining the synergistic catalytic paths of the two metal oxides, the application can realize the cracking of the cured silicone rubber, can directionally convert the cured silicone rubber into DMC (Dimethylcyclosiloxane, dimethyl cyclosiloxane mixture) with low molecular weight, and can realize the catalytic degradation of the silicone rubber only at a lower temperature (100-200 ℃), thereby greatly reducing the reaction temperature. Preferably, the phase of the TiO 2 is the anatase phase. Preferably, the phase states of the ZrO 2 include a monoclinic phase and a tetragonal phase, wherein the monoclinic phase is contained in an amount of 90wt% to 95wt% and the tetragonal phase is contained in an amount of 5wt% to 10wt%. Preferably, the TiO 2 is rod-shaped and has an aspect ratio of 5-15. The aspect ratio of TiO 2 is its length/diameter ratio. More preferably, the TiO 2 has a length of 0.5-1.5 μm and a diameter of 50-100 nm. Preferab