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CN-121988345-A - Composite carrier catalyst and preparation method and application thereof

CN121988345ACN 121988345 ACN121988345 ACN 121988345ACN-121988345-A

Abstract

The invention provides a composite carrier catalyst, a preparation method and application thereof. The composite carrier catalyst comprises a composite carrier and an active component loaded on the composite carrier, wherein the composite carrier comprises Al 2 O 3 、SiO 2 and an alkaline oxide, the active component comprises a composition with a chemical formula of AuNi a Cu b O x in terms of atomic ratio, the value range of a is 0.2-5, the value range of b is 0-5, and x is the total number of oxygen atoms required for meeting the valence of each element in the active component. The composite carrier catalyst provided by the invention can be used in the reaction of synthesizing methyl methacrylate by oxidizing and esterifying the methyl acraldehyde, has good catalytic performance, and can have the characteristics of high conversion rate of the methyl acraldehyde and high single yield of the methyl methacrylate under the condition of low Au content of the catalyst.

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
20260508
Application Date
20241108

Claims (10)

  1. 1. A composite carrier catalyst, characterized in that the catalyst comprises a composite carrier and an active component supported on the composite carrier; the composite carrier comprises Al 2 O 3 、SiO 2 and alkaline oxide; The active component comprises a composition with a chemical formula of AuNi a Cu b O x in terms of atomic ratio, Wherein, the value range of a is 0.2-5, B is in the range of 0 to 5, X is the total number of oxygen atoms required to satisfy the valence of each element in the active component.
  2. 2. The catalyst of claim 1, wherein the basic oxide comprises at least one of MgO, mnO, caO, baO; And/or the molar ratio of the basic oxide calculated by metal, al 2 O 3 calculated by Al and SiO 2 calculated by Si is (5-30): (40-90).
  3. 3. The catalyst according to claim 1 or 2, wherein the content of Au in the catalyst is (0.05-1) wt%.
  4. 4. A catalyst according to any one of claims 1 to 3, wherein the Au has a particle size of (0.5 to 4) nm.
  5. 5. The catalyst according to any one of claims 1 to 4, wherein the specific surface area of the catalyst is 50 to 350m 2 /g.
  6. 6. The method for preparing a composite supported catalyst according to any one of claims 1 to 5, comprising: S1, obtaining a first mixed solution comprising an aluminum source, a silicon source and an alkaline oxide precursor, performing spray drying on the first mixed solution to obtain a carrier precursor, and performing first roasting on the carrier precursor to obtain a composite carrier; S2, obtaining a second mixed solution comprising a nickel precursor and an optional copper precursor, and adding a reducing agent to obtain a sol comprising nickel and optional copper; s3, obtaining a solution comprising a gold precursor, adding a composite carrier and sol, stirring, washing, vacuum drying, and performing second roasting to obtain the composite carrier catalyst.
  7. 7. The method according to claim 6, wherein the first mixed solution further comprises an acid solution, and preferably the acid solution is selected from nitric acid and/or hydrochloric acid.
  8. 8. The preparation method according to claim 6 or 7, wherein the second mixed solution further comprises polyvinyl alcohol, and preferably, the ratio of the polyvinyl alcohol to the sum of the mass of the nickel precursor and the mass of the copper precursor is 0.5-5; and/or, the reducing agent comprises sodium borohydride; And/or the ratio of the molar quantity of the reducing agent to the sum of the molar quantity of the nickel precursor calculated by Ni and the molar quantity of the copper precursor calculated by Cu is 2-10.
  9. 9. The method according to any one of claims 6 to 8, wherein the first firing temperature is 400 to 800 ℃, and the first firing time is 2 to 100 hours; and/or, the first firing is performed in air; And/or the temperature of the solution comprising the gold precursor is 60-95 ℃; and/or the temperature of the second roasting is 200-500 ℃, and the time of the second roasting is 2-200 hours; And/or the second roasting is performed in air or a reducing atmosphere, preferably, the reducing atmosphere is an atmosphere containing H 2 , and the content of H 2 is 2-15% by volume.
  10. 10. Use of the composite supported catalyst according to any one of claims 1 to 5 or the composite supported catalyst prepared by the preparation method according to any one of claims 6 to 9 in the synthesis of methyl methacrylate; Preferably, the method comprises the steps of, The method comprises the steps of carrying out contact reaction on the composite carrier catalyst, methacrolein, methanol and O 2 to obtain methyl methacrylate, wherein the contact reaction condition preferably comprises the reaction temperature of 60-90 ℃, the partial pressure of O 2 of 0.02-3 MPa, the molar ratio of methanol to methacrolein of 10-40 and the reaction time of 0.5-24 h.

Description

Composite carrier catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a composite carrier catalyst and a preparation method and application thereof. 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 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. Mitsubishi chemical united states corporation plans a 35 ten thousand ton/year MMA plant built in the textarea of the Absons island, louisiana, using Alpha process technology from Lucite, mitsubishi chemical corporation. But Alpha technology is now beginning to industrialize and technology maturity and overall economy are yet 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, and the C4 resource is rich because of the production of a large amount of domestic ethylene cracking devices, thereby providing raw material assurance for the MMA preparation process by isobutene. The process route for preparing MMA from isobutene 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, and the two-step method is to oxidize and esterify the methacrolein into methyl methacrylate in one step. The two-step method has the advantages of short reaction route, high atom utilization rate, good selectivity, mild reaction condition and greenness. Wherein, the catalyst for preparing methyl methacrylate by one-step oxidation and esterification of methacrolein is the key of the technology. At present, the two-step route for preparing MMA from isobutene adopts an oxide-supported noble metal (such as Au nano-particles) catalyst. The Au nanoparticles are very advantageous for increasing the selectivity of the reaction, but are expensive. How to obtain better catalytic performance under the condition of lower usage amount of Au is a significant research direction. Disclosure of Invention In view of the above analysis, the invention aims to provide a composite carrier catalyst, a preparation method and application thereof, which are used for solving the technical problems of low conversion rate and low single-product yield (single-reaction yield) of a catalyst used in the reaction of synthesizing methyl methacrylate by oxidizing and esterifying methacrolein in the prior art. The aim of the invention is mainly achieved by the following technical scheme. In a first aspect, the present invention provides a composite supported catalyst comprising a composite support and an active component supported on the composite support; the composite carrier comprises Al 2O3、SiO2 and alkaline oxide; The active component comprises a composition with a chemical formula of AuNi aCubOx in terms of atomic ratio, Wherein, the value range of a is 0.2-5, B is in the range of 0 to 5, X is the total number of oxygen atoms required to satisfy the valence of each element in the active component. In the present invention, the value range of a may be 0.2, 0.3, 0.5, 0.8, 1, 1.2, 1.5, 2, 2.5, 2.8, 3, 3.3, 3.5, 3.8, 4, 4.5, 5, etc. The value of b can be in the range of 0, 0.2, 0.5, 0.7, 1, 1.2, 1.5, 2, 2.5, 2.8, 3, 3.3, 3.5, 3.8, 4, 4.5, 5, etc. According to some embodiments of the invention, the basic oxide comprises at least one of MgO, mnO, caO, baO. According to some embodiments of the present invention, the molar ratio of the basic oxide calculated as metal, al 2O3 calculated as Al, and SiO 2 calculated as Si is (5-30): 40-90. According to some embodiments of the present invention, the content of Au in the catalyst is (0.05 to 1) wt%, for example 0.05wt％、0.1wt％、0.15wt％、0.2wt％、0.22wt％、0.25wt％、0.3wt％、0.35wt％、0.37wt％、0.4wt％、0.44wt％、0.5wt％、0.55wt％、0.6wt％、0.67wt％、0.7wt％、0.75wt％、0.8wt％、0.85wt％、0.9wt％、0.95wt％、1wt％. According to some embodiments of the invention, the particle size of Au is (0.5-4) nm, which may be, for example, 0.5nm, 0.8nm, 1nm, 1.5nm, 2nm, 2.3nm, 2.5nm, 2.7nm, 2.8nm, 3nm, 3.1nm, 3.2nm, 3.5nm, 3.7nm, 4nm, etc. According to some embodiments of the invention, the specific surface area of the catalyst is 50-350 m 2/g, preferably 50-100 m 2/g. In a second aspect, the present invention provides a method for preparing the composite supported catalyst according to the first aspect, comprisi