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CN-121988357-A - Pd monoatomic and nanoparticle synergistic catalyst and preparation method and application thereof

CN121988357ACN 121988357 ACN121988357 ACN 121988357ACN-121988357-A

Abstract

The invention belongs to the technical field of catalysts, and particularly discloses a Pd single-atom and nanoparticle synergistic catalyst, a preparation method and application thereof, wherein an active component Pd of the catalyst is loaded on a zirconium phosphate carrier in a form of single atoms and nanoparticles, the zirconium phosphate carrier is of an amorphous structure, the specific surface area is 120-180m 2 /g, and the mass fraction of the active component Pd in the catalyst is 0.3-3wt%. The invention solves the problem that the activity and the stability of the catalyst and the selectivity can not be simultaneously combined in alkyne semi-hydrogenation reaction through a simple synthesis method.

Inventors

  • ZHANG YING
  • WANG DECHEN

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. A Pd monoatomic and nanoparticle synergistic catalyst is characterized in that, The active component Pd is loaded on a zirconium phosphate carrier in the form of monoatoms and nano particles; The zirconium phosphate carrier is of an amorphous structure, the specific surface area is 120-180m 2 /g, and the mass fraction of the active component Pd in the catalyst is 0.3-3wt%.
  2. 2. The Pd monoatomic and nanoparticle synergistic catalyst according to claim 1, wherein, The particle size of the active component Pd in the form of nano particles is 1-5nm; In the zirconium phosphate carrier, the molar ratio of Zr to P is (0.8-1.2): 1.
  3. 3. The preparation method of the Pd monoatomic and nanoparticle synergistic catalyst is characterized by comprising the following steps of: synthesizing a zirconium phosphate carrier by using ammonium dihydrogen phosphate and zirconium oxychloride octahydrate by a chemical precipitation method; and loading the active component Pd on a zirconium phosphate carrier by a wet impregnation method to obtain the Pd monoatomic and nanoparticle synergistic catalyst.
  4. 4. A process according to claim 3, wherein, A step of synthesizing a zirconium phosphate carrier from monoammonium phosphate and zirconium oxychloride octahydrate by a chemical precipitation method, comprising: Dissolving ammonium dihydrogen phosphate in water to obtain a first solution, dissolving zirconium oxychloride octahydrate in water to obtain a second solution, mixing the first solution with the second solution, centrifuging to obtain a precipitate, and drying and calcining the precipitate to obtain the zirconium phosphate carrier.
  5. 5. The method according to claim 4, wherein, The concentration of the first solution is 20-80g/L, the concentration of the second solution is 0.5-1.5mol/L, and the mol ratio of P in the first solution to Zr in the second solution is (0.8-1.2): 1; The centrifugal speed is 8000-15000rpm, the drying temperature of the precipitate is 80-120 ℃, the drying time is 10-15h, the calcining temperature is 380-420 ℃, and the calcining time is 3-5h.
  6. 6. A process according to claim 3, wherein, The step of loading the active component Pd on the zirconium phosphate carrier by a wet impregnation method comprises the following steps: Adding a zirconium phosphate carrier into a solvent to prepare a suspension; And adding a Pd source into the suspension to carry out impregnation treatment, and then carrying out rotary evaporation and drying, and reducing to obtain the Pd monoatomic and nanoparticle synergistic catalyst.
  7. 7. The method according to claim 6, wherein, The solid content of the suspension is 8.7-11.7g/L, and the Pd source comprises at least one of palladium acetate, palladium nitrate, palladium chloride and palladium sulfate; The dipping treatment temperature is 40-50 ℃, the dipping treatment time is 6-18h, the vacuum degree of rotary steaming treatment is 50-200Pa, the rotary steaming temperature is 25-60 ℃, the drying temperature is 40-80 ℃, the drying time is 6-18h, the reduction temperature is 240-300 ℃, and the reduction time is 1.5-3h.
  8. 8. Use of the Pd monoatomic and nanoparticle co-catalyst of claim 1 in the semi-hydrogenation of alkynes.
  9. 9. The use according to claim 8, wherein the alkyne is phenylacetylene or acetylene.
  10. 10. The process according to claim 9, wherein the semi-hydrogenation of phenylacetylene is carried out at normal temperature and pressure, and the semi-hydrogenation of acetylene is carried out at normal pressure and 30-65deg.C.

Description

Pd monoatomic and nanoparticle synergistic catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of catalysts, and particularly relates to a Pd monoatomic and nanoparticle synergistic catalyst, and a preparation method and application thereof. Background In the fine chemical industry, high yield and high selectivity of selective hydrogenation are achieved, and the acquisition of target products in an energy-saving and environment-friendly manner is attracting more and more attention. Among these, achieving a high selectivity of alkyne to alkene is of great importance, but this process is challenging due to the difficulty of semi-hydrogenating the carbon-carbon triple bond to a carbon-carbon double bond without further hydrogenation. Heterogeneous metal catalysts are manufactured and widely used for selective hydrogenation reactions due to their excellent catalytic properties and potential applications, wherein noble metals (such as Pd) are considered to be highly active metals in selective hydrogenation reactions. However, the β -hydrogen species formed in the subsurface region of the noble metal nanoparticle or cluster are more reactive than the adsorbed surface hydrogen species, and are very susceptible to initiating side reactions of excessive hydrogenation. Among the reported noble metal catalysts for catalyzing alkyne semi-hydrogenation, the strategy of adopting the second metal can not only improve the selectivity of alkyne semi-hydrogenation, but also enhance the catalytic activity. However, in the catalyst synthesis process, metal pairing, carrier optimization and other steps are involved, and a relatively complicated synthesis process may exist. For example, building an M 1-M2 atomic pair may require precise control over the choice of metal precursors, loading pattern, and reduction conditions, etc., ensuring good dispersion and pairing of the different metals. While optimizing the support by an "active site isolation" strategy, specialized modifications of the support are typically required so that the catalyst can avoid excessive hydrogenation reactions while ensuring high selectivity. In addition, some studies have employed interfacial effects to optimize the structural and electronic properties of the catalyst. Although this method can effectively enhance the activity and selectivity of alkyne semi-hydrogenation, the related interface engineering often requires complex process steps, such as precise regulation and control of metal-carrier interface, and may involve complex experimental procedures such as surface modification, construction of interface materials, and the like. Therefore, how to use a simple synthesis method to obtain a catalyst with high activity and high stability and simultaneously realize high selectivity of a product so as to improve the reaction efficiency is a problem to be solved in alkyne semi-hydrogenation reaction. Disclosure of Invention The invention aims to provide a Pd monoatomic and nanoparticle synergistic catalyst, a preparation method and application thereof, and the problem that the activity, stability and selectivity of the catalyst cannot be simultaneously combined in alkyne semi-hydrogenation reaction can be solved by a simple synthesis method. In order to achieve the above purpose, the invention adopts the following technical scheme: according to a first aspect of the present invention, there is provided a Pd monoatomic and nanoparticle co-catalyst, The active component Pd is loaded on a zirconium phosphate carrier in the form of monoatoms and nano particles; The zirconium phosphate carrier is of an amorphous structure, the specific surface area is 120-180m 2/g, and the mass fraction of the active component Pd in the catalyst is 0.3-3wt%. Further, the particle size of the active component Pd in nanoparticle form is 1-5nm, and the molar ratio of Zr to P in the zirconium phosphate carrier is (0.8-1.2): 1. According to a second aspect of the present invention, there is provided a method for preparing a Pd monoatomic and nanoparticle co-catalyst, comprising the steps of: synthesizing a zirconium phosphate carrier by using ammonium dihydrogen phosphate and zirconium oxychloride octahydrate by a chemical precipitation method; and loading the active component Pd on a zirconium phosphate carrier by a wet impregnation method to obtain the Pd monoatomic and nanoparticle synergistic catalyst. Further, the step of synthesizing the zirconium phosphate carrier from monoammonium phosphate and zirconium oxychloride octahydrate by using a chemical precipitation method comprises the following steps: Dissolving ammonium dihydrogen phosphate in water to obtain a first solution, dissolving zirconium oxychloride octahydrate in water to obtain a second solution, mixing the first solution with the second solution, centrifuging to obtain a precipitate, and drying and calcining the precipitate to obtain the zirconium ph