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CN-121988315-A - Water-resistant methane combustion catalyst and preparation method and application thereof

CN121988315ACN 121988315 ACN121988315 ACN 121988315ACN-121988315-A

Abstract

The invention provides a water-resistant methane combustion catalyst and a preparation method and application thereof, wherein the water-resistant methane combustion catalyst comprises an active component and a carrier, the active component comprises Pd and Pt, the carrier comprises a metal element and/or a nonmetallic element modified inorganic substance, the metal element comprises Ti and/or a rare earth element, and the nonmetallic element comprises Si; the inorganic matter comprises alumina and/or boehmite. According to the water-resistant methane combustion catalyst, pd and Pt are used as active components, and metal and/or nonmetal modified alumina is used as a carrier, so that the methane combustion catalyst has excellent water resistance, long service life, stability and low-temperature performance, and can be industrially produced and applied on a large scale.

Inventors

  • SHAN WENPO
  • ZHANG YAN
  • CAI JIEYING
  • LI JIE
  • HE HONG

Assignees

  • 中国科学院城市环境研究所

Dates

Publication Date
20260508
Application Date
20241105

Claims (10)

  1. 1. The water-resistant methane combustion catalyst is characterized by comprising an active component and a carrier, wherein the active component comprises Pd and Pt, the carrier comprises a metal element and/or a nonmetallic element modified inorganic matter, wherein the metal element comprises Ti and/or a rare earth element, and the nonmetallic element comprises Si; The inorganic matter comprises alumina and/or boehmite.
  2. 2. The water resistant methane combustion catalyst according to claim 1, wherein the rare earth element comprises La; Preferably, the support comprises a metal element and a non-metal element modified mineral comprising a Ti and Si modified mineral, a La and Si modified mineral or a La, ti and Si modified mineral, preferably a Ti and Si modified mineral.
  3. 3. The water resistant methane combustion catalyst according to claim 2, wherein the mass ratio of SiO 2 to TiO 2 in the Ti and Si modified mineral is (0.5-5): 1; Preferably, the Ti and Si modified inorganics have a SiO 2 content of 1-15wt% and a TiO 2 content of 1-10wt%.
  4. 4. The water resistant methane combustion catalyst according to claim 2, wherein the mass ratio of La 2 O 3 、SiO 2 to TiO 2 in the La, ti and Si modified mineral is (0.5-2): (0.5-5): 1; Preferably, in the La, ti and Si modified inorganic matters, the content of La 2 O 3 is 1-10wt%, the content of SiO 2 is 1-15wt% and the content of TiO 2 is 1-10wt%.
  5. 5. The water resistant methane combustion catalyst according to any one of claims 1 to 4, wherein the content of active components in the water resistant methane combustion catalyst is 0.1 to 2wt%; preferably, the molar ratio of Pd and Pt in the active component is (1-4): 1-4; Preferably, the water resistant methane combustion catalyst has a lifetime of 400 hours or more, preferably 500 hours or more, in a dry atmosphere, in an aqueous atmosphere, or under operating conditions.
  6. 6. A method of preparing the water resistant methane combustion catalyst of any one of claims 1-5, comprising the steps of: Mixing a palladium source, a platinum source, a carrier and a solvent, removing the solvent, drying and performing first roasting to obtain the water-resistant methane combustion catalyst; the carrier comprises a metal element and/or a nonmetallic element modified inorganic matter, wherein the metal element comprises Ti and/or a rare earth element, and the nonmetallic element comprises Si; The inorganic matter comprises alumina and/or boehmite.
  7. 7. The method of preparing the carrier according to claim 6, wherein the method of preparing the carrier comprises the steps of: mixing inorganic matters, a solvent and a metal source and/or a non-metal source, removing the solvent, drying and performing second roasting to obtain the carrier; the metal source comprises a titanium source and/or a rare earth source and the non-metal source comprises a silicon source.
  8. 8. The method according to claim 7, wherein the second firing is performed at a temperature of 450 to 900 ℃ for a time of 1 to 5 hours; Preferably, the means for removing the solvent comprises rotary evaporation.
  9. 9. The method according to any one of claims 6 to 8, wherein the first firing is at a temperature of 450 to 900 ℃ for a time of 1 to 5 hours; preferably, the palladium source comprises any one or a combination of at least two of palladium nitrate, palladium acetate, ammonium tetrachloropalladate, potassium chloropalladate or palladium chloride; Preferably, the platinum source comprises any one or a combination of at least two of platinum nitrate, chloroplatinic acid, tetraammine platinum nitrate, platinum acetylacetonate or platinum chloride.
  10. 10. Use of the water resistant methane combustion catalyst according to any of claims 1 to 5, wherein the use comprises for the catalytic combustion of methane under aqueous conditions.

Description

Water-resistant methane combustion catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and relates to a water-resistant methane combustion catalyst, and a preparation method and application thereof. Background Natural gas is widely used in the fields of transportation and power generation by virtue of the advantages of rich gas source, low price, small environmental pollution and high compatibility. The main component of natural gas, methane, is the global second largest greenhouse gas, and if CH 4 leaks into the atmosphere, it causes severe environmental effects. Currently, methane emissions are high, with active energy emissions being the primary source of methane, accounting for 45.6%. Therefore, elimination of CH 4 in energy activities (mobile sources, power plants, coal seam tail gas, oilfield associated tail gas, etc.) has important research significance. The elimination of CH 4 mainly comprises two modes of flame combustion method and catalytic combustion method. Direct flame combustion generally requires extremely high temperatures to start and maintain the reaction, is energy-efficient, and is prone to produce CO, NO x, etc. by-products, resulting in more serious environmental pollution. The CH 4 catalytic combustion has the characteristics of low ignition temperature, full combustion, wide applicable CH 4 concentration window and the like, and has wide application prospect in the field of CH 4 tail gas purification. Methane combustion catalysts are generally classified into noble metal catalysts and non-noble metal catalysts, wherein noble metal catalysts have low light-off temperature and good catalytic activity, and are widely focused and studied. Noble metal components commonly used for catalytic combustion of CH 4 include Pd, pt, au, rh, etc., wherein Pd-based catalysts have the optimal catalytic combustion activity for CH 4, and are widely paid attention to. In practice, the CH 4 combustion process is accompanied by the generation of a large amount of water and heat, which results in the Pd-based catalyst being susceptible to deactivation during use. In the prior art, as CN 106492824A discloses a SiO 2 -coated Pd-based noble metal nano-particle, and the Pd-based noble metal nano-particle is applied to CH 4 catalytic combustion reaction, the catalyst still has relatively excellent catalytic activity after being roasted at 900 ℃, but the preparation method of the catalyst is complex, and is difficult to realize industrial mass production. For example, CN 116713029a discloses a high-stability CH 4 combustion catalyst, which comprises palladium-platinum bimetallic nanoparticles, a nanosheet HMCM-22 molecular sieve and an auxiliary agent M, wherein the structural formula of the catalyst is m+pdpt/HMCM-22, the PdPt/HMCM-22+cao catalyst (the mass ratio is 1.0:0.1:100:100) and PdPt/HMCM-22+polyimide (the mass ratio is 1.0:1.0:100:200) are respectively balanced in [ CH 4]＝0.5％,[H2O]＝1％,[O2]＝20％,N2 ], 30000 mL/(g·h) and [ CH 4]＝0.1％,[H2O]＝5％,[O2]＝10％,N2 ] are balanced, 10000 mL/(g·h), the catalyst component is relatively complex, the cost of the catalyst is greatly increased in both noble metal and molecular sieve, and in addition, the operation condition is still a certain gap from the actual working condition, such as low water content, relatively small mass airspeed and the like. Therefore, the presently disclosed CH 4 catalytic combustion catalyst still has the defects of complex preparation method, higher cost, poor water resistance, short service life and the like, and the CH 4 combustion catalyst with low ignition temperature, good water resistance and long service life needs to be provided. Disclosure of Invention The invention aims to provide a water-resistant methane combustion catalyst, a preparation method and application thereof, wherein Pd and Pt are adopted as active components, and metal and/or nonmetal modified alumina is adopted as a carrier, so that the methane combustion catalyst has excellent water resistance, long service life, stability and low-temperature performance, and can be industrially produced and applied on a large scale. In order to achieve the aim of the invention, the invention adopts the following technical scheme: In a first aspect, the invention provides a water-resistant methane combustion catalyst comprising an active component and a support, the active component comprising Pd and Pt, the support comprising a metal element and/or a non-metal element modified mineral, wherein the metal element comprises Ti and/or a rare earth element, and the non-metal element comprises Si. According to the invention, on one hand, pt is introduced into the active component, on the other hand, the inorganic matter modified by the metal element and/or the nonmetal element is used as a carrier, and through the synergistic effect of the two aspects, the water resistance of the methane combustion catalyst ca