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CN-121988316-A - Preparation method and application of atomic-level dispersed Ru catalyst

CN121988316ACN 121988316 ACN121988316 ACN 121988316ACN-121988316-A

Abstract

The invention relates to the technical field of synthesis of organic chemical raw materials, in particular to an atomically dispersed Ru catalyst which comprises a carrier and an active metal component, wherein the active metal component is ruthenium, is loaded on the surface of the carrier in the form of atomically dispersed ruthenium clusters and is combined with defects or vacancies on the surface of the carrier, the carrier is a nano diamond/graphene composite material with a core-shell structure, and the composite material takes nano diamond as a core and graphene rich in defects as a shell to form Carbon nuclei and% The invention preferably adopts nano diamond/graphene composite material with unique core-shell structure as a carrier, and the nano diamond/graphene composite material has a carbon-shell hybridized core-shell structure The hybridized diamond core provides excellent mechanical and thermal stability The hybridized graphene shell layer is rich in edge defects and vacancies, which provide ideal, high density anchor sites for Ru species.

Inventors

  • YU LIJUN
  • WEI YONGZHI
  • LIU HONGYANG

Assignees

  • 华电辽宁能源发展股份有限公司沈阳分公司

Dates

Publication Date
20260508
Application Date
20251229

Claims (10)

  1. 1. The atomic-level dispersed Ru catalyst is characterized by comprising a carrier and an active metal component, wherein the active metal component is ruthenium, is supported on the surface of the carrier in the form of atomic-level dispersed ruthenium clusters, and is combined with defects or vacancies on the surface of the carrier; Wherein the carrier is a nano diamond/graphene composite material with a core-shell structure, the composite material takes nano diamond as a core and graphene rich in defects as a shell to form Carbon core and method for producing the same A core-shell structure with hybridized carbon shell.
  2. 2. The atomically dispersed Ru catalyst according to claim 1 wherein the loading of ruthenium in the active metal component is 0.1wt% to 2.0wt%.
  3. 3. The atomically dispersed Ru catalyst according to claim 1 or 2 wherein the support is selected from one of a nanodiamond/graphene composite, nanodiamond, graphene, activated carbon, silica, alumina or titania, preferably nanodiamond/graphene composite.
  4. 4. A method for preparing the atomically dispersed Ru catalyst according to any of claims 1-3, comprising the steps of: Step one, preparing a precursor solution, namely dissolving a ruthenium salt precursor in deionized water to prepare a mother solution with the concentration of 5-20g (calculated by metal ruthenium)/L, measuring the mother solution with the required volume according to the target load amount, adding deionized water to dilute to 4mL, and performing ultrasonic dispersion; Dispersing the carrier in deionized water, performing ultrasonic treatment to obtain uniform suspension, heating the suspension to 60-100 ℃, adding a precipitant to adjust the pH of the system to 8-11, then slowly dropwise adding the precursor solution obtained in the step one under stirring, and continuing to react for 0.5-2 hours; and step three, post-treatment and reduction, namely cooling, standing, filtering, washing and drying the mixture obtained in the step two to obtain a catalyst precursor, and then reducing the catalyst precursor in a hydrogen atmosphere at 150-250 ℃ for 1-3 hours to obtain the atomic-level dispersed Ru catalyst.
  5. 5. The method of preparing an atomically dispersed Ru catalyst according to claim 4 wherein the ruthenium salt precursor in step one is any of anhydrous ruthenium chloride, ruthenium acetylacetonate or ruthenium nitrate.
  6. 6. The method of preparing an atomically dispersed Ru catalyst according to claim 4 wherein the precipitant in step two is one or more of sodium formate, sodium carbonate, sodium bicarbonate or sodium hydroxide, preferably sodium carbonate, and the total molar ratio of sodium ions in the precipitant to ruthenium ions in the precursor solution used in step one is 500:1 to 1200:1.
  7. 7. The method for preparing an atomic-scale dispersed Ru catalyst according to claim 4, wherein in the second step, the carrier is used in an amount of 100-500mg, deionized water is used in an amount of 20-100mL, the ultrasonic treatment time is 20-60 minutes, and in the third step, the hydrogen reduction atmosphere flow rate is 20-50mL/min.
  8. 8. Use of an atomically dispersed Ru catalyst prepared according to the method of any of claims 4-7 in a selective hydrogenation of an oxygen containing aromatic compound.
  9. 9. Use of an atomically dispersed Ru catalyst according to claim 8 in a selective hydrogenation of an oxygen containing aromatic compound, in particular for the catalytic selective hydrogenation of phenol or derivatives thereof, including phenols with alkyl or alkoxy substituents, to the corresponding cyclohexanols.
  10. 10. The use of an atomically dispersed Ru catalyst according to claim 9 in a selective hydrogenation of an oxygen containing aromatic compound, wherein the selective hydrogenation is carried out in the presence of a solvent, preferably water, at a temperature of 20-100℃and a hydrogen pressure of 0.2-1.5MPa, wherein the solvent is one or more of water, methanol, ethanol, isopropanol, decalin, n-hexane or dodecane.

Description

Preparation method and application of atomic-level dispersed Ru catalyst Technical Field The invention relates to the technical field of synthesis of organic chemical raw materials, in particular to a preparation method and application of an atomic-level dispersed Ru catalyst. Background With the rapid development of global economy, more and more fossil fuels are consumed by human beings, and the concentration of carbon dioxide in the atmosphere is continuously rising, so that the search and development of a novel green renewable energy source becomes crucial, and biomass fuels are defined as renewable energy sources formed by all natural organic substances derived from plant photosynthesis in nature. Because the sulfur content and the nitrogen content of the biomass fuel are relatively low, harmful gases such as carbon dioxide, nitrogen oxides and the like released in the combustion process of the biomass fuel are far lower than those of traditional fossil energy sources, in the background, the processing of lignocellulose becomes an important research direction, wherein biomass oil is obtained through pyrolysis of lignocellulose biomass and can be upgraded into high-value chemicals through selective catalytic hydrogenation, phenolic compounds of lignin derivatives occupy 25% -30% of the biomass oil, and phenol is one of the most important constituent components. Cyclohexanol is a key intermediate for producing important chemical products such as adipic acid, cyclohexanone, nylon-66 and the like. One of the main routes to industrial production of cyclohexanol is the selective hydrogenation of phenol. Compared with the traditional high-temperature high-pressure cyclohexane oxidation process, the phenol hydrogenation route has the potential advantages of relatively mild reaction conditions, high selectivity and lower energy consumption. In addition, the study of the phenol/cyclohexanol system as a liquid organic hydrogen storage carrier (LOHCs) has been focused on, which has high hydrogen storage capacity and no CO emissions, but this places higher demands on the activity and stability of the catalyst in the hydrogenation/dehydrogenation cycle. Currently, phenol hydrogenation catalysts mainly include non-noble metal catalysts (such as raney nickel) and noble metal catalysts (such as Pt, pd, ru-based catalysts), for example, patent CN1847206a discloses a method for catalyzing phenol to synthesize cyclohexanone and cyclohexanol in one step using raney nickel, although using non-noble metals with lower cost, the reaction conditions are still severe (220 ℃ and 3.5 MPa), and raney nickel has problems of poor stability, unsafe storage and use (easy spontaneous combustion), etc., noble metal catalysts generally show higher activity, but conventional supported noble metal catalysts exist in the form of nanoparticles, the atomic utilization rate thereof is low, a large number of noble metal atoms are wrapped inside the particles to participate in the reaction, resulting in low cost efficiency, and in addition, during the reaction, particularly at higher reaction temperature, nanoparticles are liable to sinter and agglomerate, resulting in reduction of active sites, reduction of catalytic activity and stability. The atomically dispersed metal catalyst (monoatomic or sub-nanocluster catalyst) can maximally improve the atomic utilization ratio of noble metals, achieve nearly 100% atomic economy, and often exhibit excellent selectivity due to the uniform structure of active sites. However, how to stably anchor the metal atoms with high surface energy on the carrier and prevent migration and agglomeration of the metal atoms is a core challenge for preparing the catalyst, and the surface of the conventional carbon material (such as active carbon and graphene) or metal oxide carrier lacks enough specific sites capable of anchoring the metal atoms effectively, so that a preparation method and application of the atomic-level dispersed Ru catalyst are provided. Disclosure of Invention The invention aims to solve the defects in the background art and provides a preparation method and application of an atomic-level dispersed Ru catalyst. In order to solve the technical problems, the invention adopts the following technical scheme: an atomically dispersed Ru catalyst comprising a support and an active metal component, the active metal component being ruthenium, supported on the support surface in atomically dispersed ruthenium clusters and associated with defects or vacancies in the support surface; Wherein the carrier is a nano diamond/graphene composite material with a core-shell structure, the composite material takes nano diamond as a core and graphene rich in defects as a shell to form Carbon core and method for producing the sameA core-shell structure with hybridized carbon shell. Preferably, the loading of ruthenium in the active metal component is 0.1wt% to 2.0wt%. Preferably, the carrier is selected from one of nano diam