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CN-119608153-B - Preparation method and hydrogenation application of Pd-Ru synergistic catalyst based on metal organic framework

CN119608153BCN 119608153 BCN119608153 BCN 119608153BCN-119608153-B

Abstract

The invention discloses a preparation method of a Pd-Ru synergistic catalyst based on a metal organic framework and hydrogenation application thereof, wherein the Pd-Ru synergistic catalyst coated with the metal organic material is synthesized by coordinating hydrolysis of Pd-Ru alloy and tetraethyl orthosilicate by a one-pot method based on MOF materials and then high-temperature carbonization and reduction under nitrogen atmosphere: the catalyst can be used for preparing alkene by selective hydrogenation of alkyne. Compared with pure palladium or pure ruthenium, the catalyst can effectively reduce the desorption energy of styrene, limit the excessive hydrogenation of styrene, and realize high conversion rate (95.3%) and high selectivity (99.4%) of phenylacetylene under mild reaction conditions. Meanwhile, the catalyst has excellent catalytic stability and good universality, and has good application prospect.

Inventors

  • YAN PEIJIAN
  • ZHANG XITONG
  • JIANG YALI
  • LI HONGXI
  • XU JIUYUAN

Assignees

  • 聊城大学

Dates

Publication Date
20260505
Application Date
20241212

Claims (9)

  1. 1. The preparation method of the Pd-Ru synergistic catalyst based on the metal-organic framework is characterized by comprising the following steps of: S1, preparing Pd-Ru@ZIF-8: Mixing Pd 2+ 、Ru 3+ 、Zn 2+ and 2-methylimidazole in a solvent, stirring for reaction, centrifuging after the reaction is finished, and collecting a solid product to obtain Pd-Ru@ZIF-8; S2, coating Pd-Ru@ZIF-8 with silicon dioxide to prepare PdRu@ZIF-8@SiO 2 ; s3, carbonizing and reducing to prepare PdRu/C@SiO 2 , namely the Pd-Ru synergistic catalyst based on the metal organic framework; The step S3 specifically comprises the following steps: Under nitrogen atmosphere, roasting the PdRu@ZIF-8@SiO 2 prepared in the step S2 at 200-300 ℃ for 240-960min, heating to 500-700 ℃, roasting and reducing at 500-700 ℃ for 90-360min, and cooling to room temperature to obtain the PdRu/C@SiO 2 , namely the Pd-Ru synergistic catalyst based on the metal organic framework.
  2. 2. The method for preparing a metal-organic framework-based Pd-Ru synergistic catalyst according to claim 1, wherein the step S1 is specifically: S1-1, adding 2.5-10 mg Pd (Acac) 2 and 17.5-70 mg Ru (Acac) 3 into 10-50mL of a methanol mixed solution containing 280-1120 mg Zn (NO 3 ) 2 ·6 H 2 O), and uniformly mixing to obtain a mixed solution A; S1-2, adding 263-1052 mg of 2-methylimidazole into 10-50 mL methanol, and performing ultrasonic dispersion to obtain a mixed solution B; S1-3, adding the mixed solution B into the mixed solution A, stirring and reacting for 12-48h, centrifuging and collecting a solid product after the reaction is finished, washing with methanol, and drying to constant weight to obtain Pd-Ru@ZIF-8.
  3. 3. The method for preparing a metal-organic framework-based Pd-Ru synergistic catalyst according to claim 1, wherein the step S2 is specifically: And (3) adding the Pd-Ru@ZIF-8 prepared in the step (S1) into an ethanol aqueous solution, uniformly mixing, sequentially adding ammonia water, hexadecyl trimethyl ammonium bromide and tetraethyl orthosilicate, stirring for reaction, centrifugally washing a product after the reaction is finished, collecting a solid product, drying to constant weight, and grinding to obtain the PdRu@ZIF-8@SiO 2 .
  4. 4. The method for preparing a metal-organic framework-based Pd-Ru synergistic catalyst according to claim 3, wherein the step S2 is specifically: 10-40g of Pd-Ru@ZIF-8 prepared in the step S1 is added into an ethanol aqueous solution of 10-40 mL composed of ethanol and deionized water according to a volume ratio of 1:1, the mixture is uniformly mixed, 0.5-2mL of ammonia water with a mass concentration of 25% -28% is added, 250-1000 mg of hexadecyl trimethyl ammonium bromide is added, 25-100 mu L of tetraethyl orthosilicate is added after complete dissolution, stirring reaction is carried out for 6-24h, the product is centrifugally washed by the ethanol solution, a solid product is collected, dried to constant weight at 50-70 ℃, and the product is ground, thus obtaining the PdRu@ZIF-8@SiO 2 .
  5. 5. The method for preparing the metal-organic framework-based Pd-Ru synergistic catalyst according to claim 1, comprising the following steps: S1, preparing Pd-Ru@ZIF-8: S1-1, adding 5mg of Pd (Acac) 2 and 35 mg Ru (Acac) 3 into 25mL of a methanol mixed solution containing 560 mg Zn (NO 3 ) 2 ·6 H 2 O), and uniformly mixing to obtain a mixed solution A; s1-2, adding 526 mg of 2-methylimidazole into 25 mL methanol, and performing ultrasonic dispersion to obtain a mixed solution B; S1-3, adding the mixed solution B into the mixed solution A, stirring and reacting for 24 hours, centrifugally collecting a solid product after the reaction is finished, washing with methanol, drying to constant weight at room temperature, and grinding to obtain Pd-Ru@ZIF-8; S2, coating the Pd-Ru@ZIF-8 with silicon dioxide to prepare the PdRu@ZIF-8@SiO 2 : Adding 20g of Pd-Ru@ZIF-8 prepared in the step S1 into an ethanol aqueous solution of 20mL consisting of ethanol and deionized water according to a volume ratio of 1:1, uniformly mixing, adding ammonia water with a mass concentration of 25% of 1:1 mL, adding 500 mg hexadecyl trimethyl ammonium bromide, adding 50 mu L of tetraethyl orthosilicate after complete dissolution, stirring at room temperature for reaction for 12 hours, centrifugally washing a product with an ethanol solution, collecting a solid product, drying to constant weight at 60 ℃, and grinding to obtain PdRu@ZIF-8@SiO 2 ; S3, carbonizing and reducing to obtain PdRu/C@SiO 2 : Under nitrogen atmosphere, the pdru@ZIF-8@SiO 2 prepared in the step S2 is firstly roasted 480 min at 250 ℃, then heated to 600 ℃, roasted and reduced to 180 min at 600 ℃, cooled to room temperature, and the PdRu/C@SiO 2 is obtained, namely the Pd-Ru synergistic catalyst based on the metal organic framework.
  6. 6. Pd-Ru synergistic catalyst based on a metal-organic framework, characterized in that it is prepared by a process according to any one of claims 1 to 5.
  7. 7. Use of the Pd-Ru co-catalyst of claim 6 in selective hydrogenation of alkynes to produce alkenes.
  8. 8. The use according to claim 7, wherein the alkyne is any one of phenylacetylene, 2-ethynyltoluene, 3-ethynyltoluene, 4-methoxyphenylacetylene, 4-ethynylaniline, 4-ethylphenylacetylene, 4-ethynylnitrobenzene, 4-fluorophenylacetylene, 4-chlorophenylacetylene, 4-bromophenylacetylene.
  9. 9. The application according to claim 8, wherein the application method is: Uniformly mixing alkyne, ethanol and Pd-Ru synergistic catalyst, and reacting for 1-4 hours at 65-85 ℃ and 0.5-2MPa in an H 2 atmosphere to prepare corresponding alkene; Wherein the mass ratio of alkyne to ethanol to Pd-Ru synergistic catalyst is 5-20:0.5-2:0.5-2.

Description

Preparation method and hydrogenation application of Pd-Ru synergistic catalyst based on metal organic framework Technical Field The invention relates to the field of chemical synthesis, in particular to a Pd-Ru synergistic catalyst based on a metal-organic framework, a preparation method thereof and application thereof in selective hydrogenation. Background Selective hydrogenation of alkynes to olefins plays a critical role in the synthesis of fine chemicals. However, excessive hydrogenation is liable to occur during the reaction, and by-products such as alkanes are inevitably produced. It is known that the hydrogenation process of Phenylacetylene (PA) is a simple serial process, styrene (SM) is produced by the intermediate reaction, and styrene is the main raw material for the industrial production of high polymer materials such as the resin (ABS) industry, the Polystyrene (PS) industry, and the Styrene Butadiene Rubber (SBR) industry. In recent years many research efforts have been made, such as various Pd-based nanocatalysts, but styrene is further converted to Ethylbenzene (EB), a saturated product. Therefore, many researchers have made many researches on purification and separation of styrene production, wherein Pd-based nano catalyst [1-2] is the most commonly used catalyst for selective hydrogenation of phenylacetylene due to its excellent hydrogenation performance, but excessive hydrogenation of phenylacetylene is still caused due to low selectivity. In the current use process, the Pd nano-catalyst is often used by improving the preparation process of the Pd nano-catalyst or being compounded with other metals, cocatalysts and other active components, so that the Pd nano-catalyst has more excellent use performance. In recent years, research [3] shows that Ru can show good catalytic activity in the catalyst and maintain certain selectivity. On the basis, in recent years, a scholars apply the Pd-Ru synergistic catalytic system to the catalytic hydrogenation process of phenylacetylene, and the selectivity of styrene is greatly improved while the higher conversion rate is maintained. The catalytic activity is attributed to the synergistic effect of Pd-Ru single points, so that the desorption energy of styrene is reduced, and the barrier for further hydrogenation of styrene is improved, and the Pd-Ru synergistic catalytic system is possible to be applied to phenylacetylene hydrogenation. Metal Organic Frameworks (MOFs) are a class of porous materials [4] assembled by coordination of metal ions with organic matter. Because of its fine, adjustable and uniform pore structure, MOFs have become an ideal material for coating the surface of metal nanoparticles and can prevent loss and exfoliation of the nanoparticles during the reaction. In addition, the MOF material has more unsaturated sites, which is favorable for adsorption of substrates, so that the catalytic effect of the catalyst is obviously improved, and therefore, the metal organic framework has important significance for catalytic reaction. Therefore, there is an urgent need to develop a novel catalyst having high selectivity and high activity for selective hydrogenation of alkynes such as phenylacetylene. Reference to the literature [1]Sabrina Ballauri,Enrico Sartoretti,et al.Praseodymium doping in ceria-supported palladium nanocatalysts as an effective strategy to minimize the inhibiting effects of water during methane oxidation[J].A.Catalysis B:Environmental 320(2023)121898. [2]Md.Lutfor Rahman,Mohd Sani Sarjadi,et al.Silica-coated magnetic palladium nanocatalyst for Suzuki-Miyaura cross-coupling[J].A.Journal of Chemistry(2022)15,103983. [3]Wenqian Yang,Qinglin Liu,Jun Yang,et al.Ultrafifine PdRu Nanoparticles Immobilized in Metal-Organic Frameworks for Effificient Fluorophenol Hydrodeflfluorination under Mild Aqueous Conditions[J].CCS Chem.2022,4,2276-2285. [4]Annemieke Janssen,Yifeng Shi,et al.Separating Growth from Nucleation for Facile Control over the Size and Shape of Palladium Nanocrystals[J].Chemistry-A European 202001626. [5]Haiping Li,Tianxing Yang,et al.Synthesis of supported Pd nanocluster catalyst by spontaneous reduction on layered double hydroxide[J].J.of Catalysis 385(2020)313-323. [6]Qianqian Xie,Chao Lei,et al.Mesoporous ferrihydrite-supported Pd nanoparticles for enhanced catalytic dehalogenation of chlorinated environmental pollutant[J].J.of Colloid and Interface Science 608(2022)2907-2920. [7]Ming Zhang,Chaohai Wang,Chao Liu,et al.Metal-organic framework derived Co3O4/C@SiO2yolk-shell nanoreactors with enhanced catalyticperformance[J].J.Mater.Chem.A,2018,6,11226. Disclosure of Invention Aiming at the defects in the prior art, the invention provides a Pd-Ru synergistic catalyst based on a metal-organic framework, a preparation method thereof and application thereof in selective hydrogenation. In order to solve the technical problems, the invention adopts the technical scheme that in the first aspect, the invention provides a pre