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CN-122006815-A - Oxide-nitrogen-containing inherent microporous polymer nano composite carrier supported palladium catalyst, preparation method and application thereof in hydrogenation reaction

CN122006815ACN 122006815 ACN122006815 ACN 122006815ACN-122006815-A

Abstract

The invention belongs to the technical field of catalysis, and discloses an oxide-nitrogen-containing inherent microporous polymer nano composite carrier supported palladium catalyst, and a preparation method and application thereof. The catalyst takes inorganic nano-oxide as a matrix, and nitrogen-containing inherent microporous polymers are deposited on the surface of the matrix to form a composite carrier with a double-distribution pore structure, wherein the inorganic oxide provides macropores and the polymers provide micropores, the nitrogen-containing inherent microporous polymers contain tertiary amine structural units, and nitrogen atoms of the nitrogen-containing inherent microporous polymers and palladium nano particles are coordinated to realize anchoring and high dispersion of palladium. The preparation method of the catalyst comprises the steps of firstly synthesizing a nitrogen-containing inherent microporous polymer, then compounding the polymer with an oxide to prepare a carrier, and finally loading a palladium precursor and reducing the carrier by hydrogen. The catalyst provided by the invention has the advantages of high conversion rate, high selectivity and excellent cycling stability in styrene oxide hydrogenation, acrylonitrile hydrogenation and phenylacetylene hydrogenation reactions, and the preparation process is simple and convenient, and has a good industrial application prospect.

Inventors

  • WANG ZHIQIANG
  • YANG YURU

Assignees

  • 天津师范大学

Dates

Publication Date
20260512
Application Date
20260403

Claims (10)

  1. 1. An oxide-nitrogen-containing intrinsic microporous polymer nanocomposite support-supported palladium catalyst, characterized in that the catalyst comprises: an inorganic nano-oxide matrix; The nitrogen-containing inherent microporous polymer deposited on the surface of the inorganic nano oxide matrix contains tertiary amine structural units and has the following structural formula: and palladium nanoparticles supported on the composite support.
  2. 2. The catalyst of claim 1, wherein the inorganic nano-oxide is selected from at least one of alumina, silica, magnesia, titania, zirconia, or ceria.
  3. 3. The catalyst according to claim 1, wherein the nitrogen-containing intrinsic microporous polymer accounts for 0.1-20% of the mass of the composite carrier.
  4. 4. The catalyst of claim 1, wherein the palladium nanoparticle loading is 0.1-3wt.%.
  5. 5. A method for preparing the oxide-nitrogen-containing intrinsic microporous polymer nanocomposite carrier-supported palladium catalyst according to any one of claims 1 to 4, comprising the steps of: Slowly dropwise adding trifluoroacetic acid into monomer 3,3 '-dimethylbiphenyl-4, 4' -diamine and paraformaldehyde in a nitrogen atmosphere at 0 ℃, stirring for 2 days at room temperature, adjusting pH to 8-10, washing, filtering and drying precipitate to obtain a nitrogen-containing inherent microporous polymer N-PIM with a tertiary amine structure; Dissolving the N-PIM obtained in the first step in an organic solvent, adding the roasted inorganic nano-oxide, stirring, and then removing the solvent by rotary evaporation to obtain an oxide-nitrogen-containing inherent microporous polymer composite carrier; And thirdly, dissolving the palladium precursor in an alcohol solvent, adding the composite carrier obtained in the second step, stirring, removing the solvent by rotary evaporation, drying, and reducing in a hydrogen atmosphere to obtain the catalyst.
  6. 6. The method according to claim 5, wherein the temperature of the reduction in the third step is 100 to 200 ℃ for 1 to 6 hours.
  7. 7. The use of a catalyst according to any one of claims 1 to 4 in a catalytic hydrogenation reaction, wherein the hydrogenation reaction is selected from at least one of styrene oxide hydrogenation, acrylonitrile hydrogenation or phenylacetylene hydrogenation.
  8. 8. The method according to claim 7, wherein the reaction condition of the styrene oxide hydrogenation is that the catalyst is 1% -10% of the mass of the styrene oxide, the hydrogen pressure is 0.5-2.0 MPa, the temperature is 40-80 ℃, and the reaction time is 0.5-5 hours.
  9. 9. The method according to claim 7, wherein the reaction condition of the acrylonitrile hydrogenation is that the catalyst is used in an amount of 1% -10% of the mass of the acrylonitrile, the hydrogen pressure is 1.0-3.0 MPa, the temperature is 60-100 ℃, and the reaction time is 1-6 hours.
  10. 10. The application of the catalyst for the hydrogenation of phenylacetylene according to claim 7, wherein the reaction condition is that the catalyst is 5% -20% of the mass of phenylacetylene, the hydrogen pressure is 0.2-1.0 MPa, the temperature is 50-90 ℃, and the reaction time is 0.5-3 hours.

Description

Oxide-nitrogen-containing inherent microporous polymer nano composite carrier supported palladium catalyst, preparation method and application thereof in hydrogenation reaction Technical Field The invention belongs to the technical field of catalysis, and particularly relates to a supported palladium catalyst for hydrogenation reaction of unsaturated compounds, and a preparation method and application thereof. Background In modern industrial production, supported palladium (Pd) catalysts are widely used in the fields of petrochemical industry, fine chemicals, pharmaceutical synthesis, environmental protection, and the like. The catalyst support is typically an inorganic oxide of high specific surface area, such as silica, alumina, magnesia or titania, and the like. The carrier can increase the specific surface area of the catalyst, disperse the palladium active component, reduce the use amount and reduce the cost of the catalyst. However, these inorganic oxides have a single pore size distribution and a hydrophilic surface. For organic reactions, the activity and product selectivity of the catalyst are still to be improved, and in addition, the stability of the catalyst is not high, and palladium active components are easy to agglomerate in the reaction process, so that the performance of the catalyst is reduced. In general, organic polymers have better adsorption and enrichment of reactant molecules. However, the conventional polymer has low specific surface area and poor heat resistance. Porous microspheres can be obtained through a pore-forming agent and a crosslinking method, but the preparation is complex, the specific surface area is not high, for example, gas-phase silica gel is used as the pore-forming agent in US5168104, suspension polymerization is adopted to carry out copolymerization of divinylbenzene and hydroxyethyl methacrylate, then strong alkali is used to etch the silica gel to obtain porous polymer particles with the particle size larger than 0.1 mu m, the suspension polymerization method is adopted in US6583082 and US6750303 to copolymerize hydroxyethyl methacrylate functional monomers and divinylbenzene monomers to obtain polymer carriers with the specific surface area larger than 10m 2/g, the particle size of the particles is 0.1-1000 mu m and the pore volume larger than 0.2ml/g, and the terpolymer carriers are prepared by introducing the functional monomers of hydroxyl methacrylate in CN201310520354.4, CN201310520841.0 and CN201410806511.2, but the specific surface area of the prepared polymer carriers is small, which is not beneficial to the loading of subsequent noble metal catalysts, and the pore-forming agent is required to be added. Organic-inorganic composite supports have been attempted to integrate the advantages of both types of supports. For example, yang et al (macromol. Mater. Eng.2003,288, 380-385) coated a polystyrene film on the surface of silica gel with an average particle size of 120-181 nm by surface emulsion polymerization to obtain monodisperse silica gel/polystyrene core-shell nanoparticles. Wan et al (Mater. Lett.2008,62,37-40) used a microwave-assisted emulsion polymerization process to prepare core-shell structured TiO 2/polystyrene nanoparticle materials. Chinese patent CN1814629 proposes that inorganic nanoparticles be introduced into emulsion polymerization solution, and that organic monomers be in situ compounded with inorganic nanoparticles during emulsion polymerization to form core-shell inorganic/organic composite material with nanoparticles as core and polymers as shell. However, the emulsion polymerization requires the addition of various initiators and monomers, and the operation is complicated. In addition, these polymers are generally polyethylene-based polymers, which do not have strong interactions with the active metal at the expense of specific surface area or pore volume, and the active metal Pd is easily lost during the reaction. Therefore, a novel carrier material which has high specific surface area, proper double-distribution pore structure, strong metal-carrier interaction and simple preparation is developed, and has important significance for improving the comprehensive performance of the supported palladium catalyst. Disclosure of Invention The invention aims to provide an oxide-nitrogen-containing inherent microporous polymer nano composite carrier supported palladium catalyst, which aims to solve the problems that an inorganic oxide carrier in the prior art is strong in hydrophilicity, single in pore structure, easy to agglomerate in metal, low in specific surface area, weak in interaction with active metal and the like. In order to achieve the above purpose, the invention adopts the following technical scheme: the first aspect of the invention provides an oxide-nitrogen-containing intrinsic microporous polymer nanocomposite carrier supported palladium catalyst, which comprises: an inorganic nano-oxide matrix; The nitrogen-containing