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CN-122006740-A - Gold-based composite oxide catalyst and preparation method and application thereof

CN122006740ACN 122006740 ACN122006740 ACN 122006740ACN-122006740-A

Abstract

The invention discloses a gold-based composite oxide catalyst and a preparation method and application thereof. The catalyst comprises an active component and a carrier, wherein the active component comprises a general formula AuM a O x shown in the specification, M is at least one of Ni, fe and Cu, a=0.2-10, x is the total number of oxygen atoms required for meeting the valence of other elements, and the carrier is a composite oxide SiO 2 -NiO-MgO-CeO 2 . The catalyst provided by the invention is used for the reaction of synthesizing methyl methacrylate by oxidizing and esterifying the methacrolein, and has the characteristics of high catalytic activity, high single yield of the product methyl methacrylate and the like.

Inventors

  • XU WENJIE
  • SONG WEILIN
  • YANG BIN

Assignees

  • 中石化（上海）石油化工研究院有限公司
  • 中国石油化工股份有限公司

Dates

Publication Date
20260512
Application Date
20241108

Claims (13)

  1. 1. A gold-based composite oxide catalyst is characterized by comprising an active component and a carrier, wherein the active component comprises a general formula AuM a O x shown in the specification, M is at least one of Ni, fe and Cu, a=0.2-10, and x is the total number of oxygen atoms required for satisfying the valence of other elements; The carrier is composite oxide SiO 2 -NiO-MgO-CeO 2 .
  2. 2. The catalyst according to claim 1, wherein the carrier comprises 3% -20% of NiO, 3% -20% of MgO, 3% -22% of CeO 2 and 40% -91% of SiO 2 based on the mass of the carrier; And/or, in the catalyst, the content of Au is 0.05wt% to 1.0wt% based on the mass of the catalyst.
  3. 3. Catalyst according to claim 1, characterized in that the average particle size of the Au particles in the catalyst is 0.5-5nm, preferably 1-4nm; and/or the specific surface area of the catalyst is 10-300m 2 /g.
  4. 4. A method for producing the gold-based composite oxide catalyst according to any one of claims 1 to 3, comprising the steps of: (1) Mixing a nickel source, a magnesium source, a cerium source, a silicon source and water, and drying to obtain a carrier precursor; (2) And (3) performing first roasting on the carrier precursor in the step (1) in an oxygen-containing atmosphere, and performing second roasting on the carrier precursor in an ammonia-containing atmosphere to obtain the carrier. (3) And mixing gold salt, M metal salt and the carrier for loading, drying, and roasting for the third time in an oxygen-containing atmosphere to obtain the catalyst.
  5. 5. The method according to claim 4, wherein in the step (1), the nickel source is at least one selected from the group consisting of nickel nitrate, nickel chloride and nickel acetate; And/or the magnesium source is at least one selected from magnesium nitrate, magnesium chloride, magnesium sulfate and magnesium acetate; and/or the cerium source is selected from cerium nitrate, cerium oxide, cerium sulfate, cerium ammonium sulfate; And/or the silicon source is at least one selected from silica sol, silica micropowder and tetraethoxysilane.
  6. 6. The method according to claim 4, wherein in the step (1), the nickel source is calculated as Ni, the magnesium source is calculated as Mg, the cerium source is calculated as Ce, the silicon source is calculated as Si, and the molar ratio of the nickel source, the magnesium source, the cerium source and the silicon source is (0.01-1): 0.01-1.
  7. 7. The method according to claim 4, wherein in the step (1), the drying is spray drying, and the drying conditions are an inlet temperature of 300-350 ℃ and an outlet temperature of 120-180 ℃ and a spray disk rotation speed of 15000-25000r/min.
  8. 8. The method according to claim 4, wherein in the step (2), the first firing is performed at a temperature of 500 to 800 ℃ for 2 to 100 hours, and the second firing is performed at a temperature of 450 to 750 ℃ for 1 to 72 hours; and/or, in the step (2), the temperature of the second roasting is lower than that of the first roasting, preferably the temperature difference that the temperature of the second roasting is lower than that of the first roasting is not lower than 50 ℃; and/or in the step (2), the ammonia volume ratio in the ammonia-containing atmosphere is 1-14%.
  9. 9. The method according to claim 4, wherein in the step (3), the gold salt is chloroauric acid, and the M metal salt is an oxygen-containing salt and/or an oxygen-containing salt hydrate of one or more elements selected from Ni, fe and Cu; And/or in the step (3), the gold salt accounts for 0.05-1.0 wt% of the final catalyst in terms of Au metal introduction amount by mass, the M metal salt accounts for 0.2-10 mole ratio of the M metal salt and the gold salt by mass and the M element.
  10. 10. The method according to claim 4, wherein in the step (3), the temperature of the third firing is 200-500 ℃, the temperature rising rate is 0.5-5 ℃ per minute, the firing time is 2-200 hours, and the oxygen-containing atmosphere is oxygen or air.
  11. 11. Use of the gold-based composite oxide catalyst according to any one of claims 1 to 3 and/or the gold-based composite oxide catalyst prepared by the preparation method according to claims 4 to 10 in a reaction for synthesizing methyl methacrylate by oxidative esterification of methacrolein.
  12. 12. The method according to claim 11, wherein the method comprises reacting methacrolein, methanol and an oxygen-containing gas in contact with the catalyst to obtain methyl methacrylate.
  13. 13. The process according to claim 11, wherein the reaction conditions are a reaction temperature of 60-90 ℃, an O 2 partial pressure of 0.02-3MPa, a molar ratio of methanol to methacrolein of 10-40, a mass ratio of methacrolein to catalyst of 1-3, and a reaction time of 0.5-24h.

Description

Gold-based composite oxide catalyst and preparation method and application thereof Technical Field The invention relates to the field of chemical synthesis, in particular to a gold-based composite oxide catalyst and a preparation method thereof, and application thereof in the reaction of synthesizing methyl methacrylate by oxidizing and esterifying methacrolein. Background Methyl Methacrylate (MMA) is an important organic chemical raw material, and is mainly used for producing organic glass (PMMA), polyvinyl chloride auxiliary ACR and a second monomer used for producing acrylic fibers, and can also be used for producing coatings, adhesives, lubricants, textile dyes and the like. In recent years, demand for MMA has increased worldwide, and the productivity and supply amount thereof have been increasing. In the existing industrialized MMA production process, raw material hydrocyanic acid in the traditional ACH method process route is greatly affected by the running condition of acrylonitrile, so that the production cost advantage of the ACH method is reduced. The Alpha technology is now beginning to industrialize, and Mitsubishi chemical U.S. company plans a 35 ten thousand ton/year MMA plant built in the teaching area of the Absons pine island, louisiana, whose technical maturity and overall economy are to be further examined. Compared with other processes, the direct oxidation method using C4 as the raw material has the advantages of wide raw material source, good economy and the like. The process route is divided into a three-step method and a two-step method, wherein the three-step method is to oxidize isobutene into methacrolein, further oxidize the methacrolein into methacrylic acid, and finally esterify the methacrylic acid with methanol to obtain methyl methacrylate. The two-step method combines the oxidation reaction and the esterification reaction into one step to obtain the methyl methacrylate. The two-step method route has the advantages of short reaction route, high atom utilization rate, good selectivity, mild reaction condition, greenness and the like, and is a great innovation for producing MMA by the C4 route. The catalyst for preparing methacrylic acid by one-step oxidation and esterification of methacrolein is key to the technology. At present, an oxide supported noble metal catalyst is mostly adopted, for example, 1.1wt% of Au nano-particles are supported on a composite oxide carrier such as SiO 2-Al2O3 -MgO by Suzuki, etc. of the Asahi Kasei Co., ltd, and the catalyst cost is as high as millions per ton. The selectivity of the Au nano-particles for the reaction is improved, but the cost is high, and how to reduce the use amount of Au needs to develop better auxiliary agents and carriers to promote the activity of the nano-gold particles. In the conventional method, such as CN117861685A, in order to avoid the growth of Au particles, the conventional catalyst is SiO 2 doped with alkali metal, auNi is loaded on the catalyst, the carrier is firstly roasted at high temperature, and then the catalyst is roasted at low temperature, so that incomplete Ni roasting is often caused, and the stability of the surface active site Au-NiO is not high, thereby influencing the activity of the catalyst. Disclosure of Invention The invention aims to solve the technical problems of low conversion rate of a catalyst used in the reaction of synthesizing methyl methacrylate by oxidizing and esterifying methacrolein and low single yield of a product in the prior art, and provides a gold-based composite oxide catalyst, a preparation method and application thereof. The catalyst provided by the invention is used for the reaction of synthesizing methyl methacrylate by oxidizing and esterifying the methacrolein, and has the characteristics of high catalytic activity, high single yield of the product methyl methacrylate and the like. The first aspect of the invention provides a gold-based composite oxide catalyst, wherein the catalyst comprises an active component and a carrier, and the active component comprises a general formula AuM aOx, wherein M is at least one of Ni, fe and Cu, a=0.2-10, and x is the total number of oxygen atoms required for meeting the valence of other elements; The carrier is composite oxide SiO 2-NiO-MgO-CeO2. Further, a=0.2 to 10 in AuM aOx, for example, 0.5, 0.8, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10, etc., and any value in a range formed by any two of these values. Further, in the carrier, based on the mass of the carrier, the content of NiO is 3% -20%, the content of MgO is 3% -20%, the content of CeO 2 is 3% -22%, and the content of SiO 2 is 40% -91%. Further, in the support, the NiO content is 3% to 20%, for example, 3%, 5%, 9%, 10%, 15%, 17%, 20%, etc., based on the mass of the support, and any value in a range constituted by any two of these values. Further, the MgO content in the carrier is 3% to 20%, for example, 3%, 4%, 5%, 9%, 10%, 15%, 17%, 20%, etc., based on the mass of