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CN-122006748-A - Catalyst for low-temperature oxidation removal of carbon monoxide and volatile organic compounds, and preparation method and application method thereof

CN122006748ACN 122006748 ACN122006748 ACN 122006748ACN-122006748-A

Abstract

The invention provides a catalyst for low-temperature oxidation removal of carbon monoxide and volatile organic compounds, a preparation method and a use method thereof. The catalyst comprises a porous catalyst carrier and an active component loaded on the porous catalyst carrier, wherein the active component comprises noble metal and at least one or a combination of transition metal and catalyst auxiliary agent, wherein the mass ratio of the transition metal to the noble metal is (0-10): 1, the mass ratio of the catalyst auxiliary agent to the noble metal is (0-10): 1, and the mass content of the noble metal is 0.1% -10% based on the total mass of the catalyst. The catalyst has high catalytic activity, and is suitable for low-temperature carbon monoxide (CO) and Volatile Organic Compounds (VOC) oxidation removal in various application scenes.

Inventors

  • HU QINGYUAN
  • GUO LIXING
  • ZONG YUHAO
  • LIU KAIMING
  • WANG HU
  • SHI TAO

Assignees

  • 大唐南京环保科技有限责任公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. The catalyst for removing carbon monoxide and volatile organic compounds by low-temperature oxidation is characterized by comprising a porous catalyst carrier and an active component loaded on the porous catalyst carrier, wherein the active component comprises noble metal and at least one or a combination of transition metal and catalyst auxiliary agent, the mass ratio of the transition metal to the noble metal is (0-10): 1, the mass ratio of the catalyst auxiliary agent to the noble metal is (0-10): 1, and the mass content of the noble metal is 0.1% -10% based on the total mass of the catalyst.
  2. 2. The catalyst according to claim 1, wherein the noble metal is at least one selected from the group consisting of platinum, palladium, rhodium, ruthenium, iridium, gold; Preferably, the noble metal has an average crystallite size of 10 nm or less, preferably 5 nm or less.
  3. 3. The catalyst according to claim 1 or 2, wherein the transition metal is selected from at least one of iron, copper, cobalt, nickel, manganese; Preferably, the catalyst promoter is at least one selected from bismuth and tin; preferably, the porous catalyst carrier is at least one selected from CeO 2 、TiO 2 、ZrO 2 、Al 2 O 3 and zeolite.
  4. 4. A catalyst according to any one of claims 1 to 3, characterized in that the mass ratio of the transition metal to the noble metal is (2-4): 1, the mass ratio of the catalyst auxiliary to the noble metal is (2-4): 1, and the mass content of the noble metal is 0.5-5%.
  5. 5. A structured catalyst, characterized in that it comprises a monolithic support and the catalyst of any one of claims 1 to 4 coated on said monolithic support; preferably, the monolithic support is selected from at least one of a honeycomb ceramic support, a metal honeycomb support, a foam metal support, a wire mesh support, a corrugated plate support, a polymer support.
  6. 6. A method for preparing the catalyst according to any one of claims 1 to 5, comprising the steps of: (1) Dissolving precursors of noble metal, transition metal and catalyst auxiliary agent to obtain impregnating solution, loading the impregnating solution on a porous catalyst carrier, and then drying to obtain the catalyst of any one of claims 1 to 4; (2) Mixing the catalyst obtained in the step (1) with a binder to prepare catalyst slurry, coating the catalyst slurry on a monolithic carrier, and drying and calcining to obtain the structural catalyst of claim 5.
  7. 7. The method of claim 6, wherein in step (1), the precursor of the noble metal is a noble metal salt, preferably comprising at least one of the soluble salts of platinum, palladium, rhodium, ruthenium, iridium, gold; preferably, the soluble salt of platinum comprises platinum nitrate and the soluble salt of palladium comprises palladium nitrate; Preferably, the precursor of the transition metal is a transition metal salt, preferably comprising at least one of soluble salts of iron, copper, cobalt, nickel, manganese; Preferably, the precursor of the catalyst promoter comprises at least one of bismuth and tin soluble salts, preferably at least one of bismuth nitrate, bismuth acetate and tin chloride; Preferably, the loading is carried out by adopting an incipient wetness impregnation method, a rotary evaporation method or a spray drying method; Preferably, the drying is carried out above 60 ℃, preferably between 80-120 ℃.
  8. 8. The method according to claim 6 or 7, wherein in the step (2), the binder is at least one selected from pseudo-boehmite, alumina sol, nano-alumina hydrate, nano-alumina suspension, nano-silica suspension, silica sol, and zirconium acetate; Preferably, the addition amount of the binder is 2% -20% of the total mass of the catalyst obtained in the step (1), preferably 5% -10%; Preferably, the catalyst slurry has a solids content of 15% to 50%, preferably 30% to 40%; Preferably, the monolithic support is selected from at least one of a honeycomb ceramic support, a metal honeycomb support, a foam metal support, a wire mesh support, a corrugated plate support, a polymer support; Preferably, the catalyst slurry is applied in an amount of 0.02 to 0.5g/cm 3 , preferably 0.05 to 0.2 g/cm 3 , with a noble metal loading of 0.1 to 10 mg/cm 3 , preferably 0.5 to 5 mg/cm 3 ; Preferably, the drying is performed at a temperature above 70 ℃ of 6 h or more, preferably at a temperature of 90-120 ℃ of 9-15 h; Preferably, the calcination is carried out at a temperature above 450 ℃ of above 1h, preferably at 500-600 ℃ of 1-3 h.
  9. 9. A method for oxidative removal of carbon monoxide and volatile organic compounds using the catalyst according to any one of claims 1 to 5, characterized in that the catalyst is subjected to a reduction treatment to convert an active metal component into a reduced state before use, and then a gas containing carbon monoxide and/or volatile organic compounds is brought into contact reaction with the reduced catalyst at a temperature of not higher than 150 ℃ under normal pressure.
  10. 10. The method according to claim 9, wherein the operating conditions of the reduction treatment are treatment of 1.1 h or more, preferably 1.5 to 3. 3 h, under a mixed atmosphere of a reducing gas and a protective gas at 300 to 500 o C; preferably, the reducing gas is hydrogen and the protective gas is nitrogen; Preferably, the contacting reaction is carried out at a temperature of from room temperature to 150 ℃; Preferably, the volatile organic compound includes at least one of aldehydes, alcohols, alkanes, alkenes, organic acids, and aromatic compounds; Preferably, the oxidative removal of carbon monoxide, formaldehyde, methanol or formic acid is carried out at room temperature.

Description

Catalyst for low-temperature oxidation removal of carbon monoxide and volatile organic compounds, and preparation method and application method thereof Technical Field The invention relates to the technical field of catalysts, in particular to a catalyst for low-temperature oxidation removal of carbon monoxide and volatile organic compounds and a preparation method thereof. Background Carbon monoxide (CO) and Volatile Organic Compounds (VOCs) are two widely occurring and significant classes of atmospheric pollutants. CO is strongly toxic to humans and animals due to its high affinity for hemoglobin, and even at lower concentrations (e.g., 100 ppm) reduces the efficiency of oxygen transport in blood. VOCs are a wide variety of important precursors that cause environmental problems such as photochemical smog and ozone layer destruction. The CO and VOC are generated in a wide range of channels and modes, and in industrial waste gas, the CO and VOC often come from incomplete combustion of fossil fuel, and use and emission of industrial production process and VOCs-containing products, and the CO and VOC-containing waste gas has the characteristics of high emission concentration, large emission amount and complex components. In addition to industrial emissions, CO and VOCs are also emitted from vehicles, airplanes, sewage treatment plants, light industrial facilities, certain small enterprises (such as dry cleaning shops, bakeries, restaurants, etc.), and families, wherein VOCs in the home environment mainly originate from interior decoration, daily necessities and human activities, and are characterized by multiple sources, wide range, long-term low-concentration release, and more direct relationship with human health, especially formaldehyde, which is a main indoor air pollutant, has been increasingly emphasized in recent years due to its carcinogenicity. Currently, thermocatalytic oxidation is the dominant technology for treating such exhaust gases, but it relies on high temperatures (typically above 250 ℃) to achieve complete oxidation of CO and VOCs, resulting in huge energy consumption and high operating costs. Therefore, development of purification technologies capable of operating efficiently at low temperatures, or even at room temperature, has become an urgent need. Currently known techniques for low temperature removal of VOCs and CO include photocatalysis, electrochemical catalysis, adsorption and catalytic oxidation. However, achieving complete oxidative removal of VOCs and/or CO at lower temperatures remains a challenging topic. It is critical in this field to develop oxidation catalysts that are more active and have sufficient stability and durability to enable complete oxidation of CO and VOCs at lower temperatures. In view of this, the present invention has been made. Disclosure of Invention The invention aims to provide a catalyst for removing carbon monoxide and volatile organic compounds by low-temperature oxidation, and a preparation method and a use method thereof, which at least solve the technical problems of high energy consumption, high cost and poor catalyst stability of the traditional thermal catalytic oxidation at present. According to a first aspect of the invention, a catalyst for removing carbon monoxide and volatile organic compounds by low-temperature oxidation is provided, which is characterized by comprising a porous catalyst carrier and an active component loaded on the porous catalyst carrier, wherein the active component comprises noble metal and at least one or a combination of transition metal and catalyst auxiliary agent, the mass ratio of the transition metal to the noble metal is (0-10): 1, the mass ratio of the catalyst auxiliary agent to the noble metal is (0-10): 1, and the mass content of the noble metal is 0.1% -10% based on the total mass of the catalyst. In a second aspect of the present invention, there is provided a structural catalyst comprising a monolith support and the above catalyst coated on the monolith support. In a third aspect of the present invention, there is provided a method for preparing the above catalyst of the present invention, comprising the steps of: (1) Dissolving precursors of noble metal, transition metal and catalyst auxiliary agent to obtain impregnating solution, loading the impregnating solution on a porous catalyst carrier, and drying to obtain the catalyst of the first aspect; (2) Mixing the catalyst obtained in the step (1) with a binder to prepare catalyst slurry, coating the catalyst slurry on a monolithic carrier, and drying and calcining to obtain the structural catalyst in the second aspect. In a fourth aspect of the present invention, there is provided a method for oxidative removal of carbon monoxide and volatile organic compounds using the above catalyst, wherein the above catalyst or the structural catalyst is subjected to a reduction treatment to convert an active metal component into a reduced state before use, and the