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CN-121988314-A - Attapulgite-based noble metal supported catalyst and preparation method and application thereof

CN121988314ACN 121988314 ACN121988314 ACN 121988314ACN-121988314-A

Abstract

The invention provides a preparation method of a attapulgite-based noble metal-loaded catalyst, which comprises the following steps of uniformly dispersing acid-modified attapulgite in an acidic noble metal precursor aqueous solution, carrying out electrolytic reaction under the action of supergravity, adding an adhesive after the electrolytic reaction is finished to obtain a noble metal-attapulgite impregnating solution, impregnating the acidified cordierite honeycomb ceramic in the noble metal-attapulgite impregnating solution, aging, drying and roasting to obtain the attapulgite-based noble metal-loaded catalyst. According to the method, the attapulgite with large specific surface area is selected, and the noble metal salt is reduced in situ and uniformly dispersed on the attapulgite by means of the combination of the supergravity and electrolysis of the special pore channels, so that the noble metal salt is loaded on the cordierite honeycomb ceramic, the synchronous impregnation and reduction of the noble metal on the attapulgite are realized, and the noble metal with high catalytic activity is loaded and the use amount of the noble metal is reduced under the condition of reducing the use of reagents such as a surfactant, a reducing agent and the like.

Inventors

  • JIANG YAN
  • CHENG HAO
  • YAO CHAO
  • LI MIAOMIAO
  • LI XIAZHANG
  • ZUO SHIXIANG
  • YANG SHENGZHI
  • ZHANG YUAN
  • WANG KUN
  • LI JINGRUI

Assignees

  • 中国石油天然气股份有限公司

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. The preparation method of the attapulgite-based noble metal-loaded catalyst is characterized by comprising the following steps of: S1, uniformly dispersing acid modified attapulgite in an acidic noble metal precursor aqueous solution, carrying out electrolytic reaction under the action of supergravity, and adding an adhesive after the electrolytic reaction is finished to obtain a noble metal-attapulgite impregnating solution; S2, soaking the acidified cordierite honeycomb ceramic in the noble metal-attapulgite impregnating solution, aging, drying and roasting to obtain a attapulgite-based noble metal-loaded catalyst; wherein the strength G of the super gravity field is 300-500G, and the direction of the super gravity field is parallel to the surface of the cathode.
  2. 2. The method according to claim 1, wherein the current density is 1 to 8a/dm 2 and the electrolysis time is 20 to 80min.
  3. 3. The method of claim 1, wherein the aqueous acidic noble metal precursor solution has a pH of 1 to 5.
  4. 4. The preparation method of the acid-modified attapulgite according to claim 1, wherein the preparation method of the acid-modified attapulgite comprises the following steps: Adding attapulgite powder into an inorganic acid solution with the H + concentration of 0.5-5 mol/L, stirring for 2-12H, separating, washing and drying to obtain the acid modified attapulgite.
  5. 5. The preparation method of claim 4, wherein the mass ratio of the binder to the attapulgite powder is 1 (5-20).
  6. 6. The method of making according to claim 1, wherein the method of making the acidified cordierite honeycomb ceramic comprises the steps of: Immersing 80-480 meshes of cordierite honeycomb ceramics in an inorganic acid solution with the volume concentration of 5% -10% for 6-12 hours to obtain the acidified cordierite honeycomb ceramics.
  7. 7. The method of claim 1, wherein the noble metal in the aqueous acidic noble metal precursor solution is selected from the group consisting of platinum and/or palladium; The binder is at least one selected from hydroxypropyl cellulose, polypropylene alcohol, polyvinyl alcohol and carboxymethyl cellulose.
  8. 8. The preparation method of claim 1, wherein the aging temperature is 20-40 ℃ and the time is 1-12 hours; The drying temperature is 100-120 ℃ and the drying time is 1-8 hours; the roasting temperature is 400-600 ℃ and the roasting time is 2-10 hours.
  9. 9. The attapulgite noble metal-supported catalyst prepared by the method for preparing a attapulgite noble metal-supported catalyst according to any one of claims 1 to 8, wherein a skeletal support in the attapulgite noble metal-supported catalyst comprises cordierite honeycomb ceramic, noble metal is supported on attapulgite, and attapulgite supporting the noble metal is supported on the cordierite honeycomb ceramic; Preferably, the attapulgite accounts for 100-400 g/L of the volume of the attapulgite-based noble metal-supported catalyst, and the noble metal accounts for 0.2-4 g/L of the volume of the attapulgite-based noble metal-supported catalyst.
  10. 10. Use of the attapulgite clay-supported noble metal catalyst prepared by the preparation method of the attapulgite clay-supported noble metal catalyst according to any one of claims 1 to 8 in VOC exhaust gas treatment.

Description

Attapulgite-based noble metal supported catalyst and preparation method and application thereof Technical Field The invention relates to the technical field of catalysts, in particular to a attapulgite-based noble metal-loaded catalyst, and a preparation method and application thereof. Background Volatile Organic Compounds (VOCs) refer to organic compounds with saturated vapor pressure of more than 70Pa at normal temperature and boiling point below 260 ℃ at normal pressure, have high volatility, contain many cancerogenic substances and damage the liver, kidney, brain and nervous system of people, and are main pollutants causing PM2.5 and O 3 in the atmosphere to rise. Among the VOCs treatment technologies, the catalytic oxidation technology is one of the most promising and efficient chemical treatment technologies, and has the advantages of low-temperature catalytic activity (200-500 ℃), no secondary pollution (avoiding nitrogen oxide generation), high treatment efficiency (the removal efficiency is mostly more than 95%), wide application range and the like. The catalyst is used as the core of the catalytic oxidation technology and is the key for improving the technical performance. The VOCs catalyst which is industrially applied at present mainly comprises a supported noble metal catalyst, and is widely used for the catalytic oxidation of the VOCs due to the excellent catalytic performance and high stability. The carrier is used as an important component of the supported catalyst, and directly influences the structure, the property and the catalytic performance of the catalyst. The proper carrier needs to have proper specific surface area and pore structure, stable crystal phase structure, thermal stability and good mass transfer performance, ensures uniform distribution and high dispersion of active components, and improves the use efficiency of the active components. Attapulgite (ATP) is a natural nano clay mineral fiber, has good adsorption performance, unique pore structure and potential active site, and can be used as an ideal carrier of a catalyst. In the catalytic process, ATP can be used as a high-efficiency carrier, and particularly has excellent performance in treating VOCs pollutants mainly containing benzene series. The supported noble metal catalyst is prepared by coating a carrier and an active component on a honeycomb ceramic or metal corrugated plate framework in sequence. In the process, the preparation of surfactants, reducing agents and other agents is needed, the operation steps are complicated, the ATP pore canal is complicated, the loading ratio of active components in the pore canal is low, the active components in the prepared noble metal catalyst are easy to agglomerate, the active components cannot be effectively utilized, the catalytic efficiency of the catalyst is reduced, and the noble metal usage amount is high. The preparation method comprises the steps of adding graphite oxide into deionized water, carrying out ultrasonic treatment to obtain graphene oxide dispersion liquid, adding nickel sulfamate, nickel chloride and ammonium chloride into the graphene oxide dispersion liquid, carrying out ultrasonic treatment to obtain composite plating liquid, taking a foam nickel substrate subjected to ultrasonic and acidification treatment as an electrodeposition cathode, taking a pure nickel tube as an electrodeposition anode, and jointly depositing graphene and metallic nickel on the surface of the pretreated foam nickel by a supergravity electrodeposition method to obtain the Ni/rGO composite plating layer with a 3D structure and high catalytic hydrogen evolution activity. The method uses the carrier as an electrodeposited cathode to prepare the composite electrode, and the supergravity is used for strengthening mass transfer and inhibiting the influence of gas on a coating, and can improve the content of carbon in the cathode. The Chinese patent document CN115845872A discloses a method for preparing an integral catalyst by utilizing a hypergravity reactor, which comprises the following steps of S1, carrying out acid etching pretreatment on the surface of a carrier, S2, preparing a coating, S3, filling the carrier treated in the step S1 into a rotor of the hypergravity reactor, introducing coating slurry obtained in the step S2 into the hypergravity reactor under a hypergravity environment, starting a motor and a centrifugal pump, conveying the coating slurry into a liquid distributor of the hypergravity reactor through the centrifugal pump, spraying the coating slurry into a rotor through an injection hole, returning the coating slurry to a feed liquid storage tank after passing through the rotor, carrying out cyclic reaction for a period of time, taking the carrier loaded with the coating out, drying at room temperature, drying in an oven, finally putting the carrier into a tube furnace for roasting, and loading active components by an impregnation method to obtain the integral ca