CN116651442A - Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof - Google Patents

Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof Download PDF

Info

Publication number
CN116651442A
CN116651442A CN202310711695.3A CN202310711695A CN116651442A CN 116651442 A CN116651442 A CN 116651442A CN 202310711695 A CN202310711695 A CN 202310711695A CN 116651442 A CN116651442 A CN 116651442A
Authority
CN
China
Prior art keywords
sio
catalyst
carrier
preparation
reaction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310711695.3A
Other languages
Chinese (zh)
Inventor
张健康
许浩
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Northwestern Polytechnical University
Original Assignee
Northwestern Polytechnical University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Northwestern Polytechnical University filed Critical Northwestern Polytechnical University
Priority to CN202310711695.3A priority Critical patent/CN116651442A/en
Publication of CN116651442A publication Critical patent/CN116651442A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
    • B01J23/42—Platinum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/0272—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255
    • B01J31/0274—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255 containing silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
    • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
    • B01J31/0272—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255
    • B01J31/0275—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides containing elements other than those covered by B01J31/0201 - B01J31/0255 also containing elements or functional groups covered by B01J31/0201 - B01J31/0269
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
    • B01J35/391—Physical properties of the active metal ingredient
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C209/00—Preparation of compounds containing amino groups bound to a carbon skeleton
    • C07C209/30—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds
    • C07C209/32—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups
    • C07C209/36—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups by reduction of nitro groups bound to carbon atoms of six-membered aromatic rings in presence of hydrogen-containing gases and a catalyst
    • C07C209/365—Preparation of compounds containing amino groups bound to a carbon skeleton by reduction of nitrogen-to-oxygen or nitrogen-to-nitrogen bonds by reduction of nitro groups by reduction of nitro groups bound to carbon atoms of six-membered aromatic rings in presence of hydrogen-containing gases and a catalyst by reduction with preservation of halogen-atoms in compounds containing nitro groups and halogen atoms bound to the same carbon skeleton
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/02—Pretreatment of the material to be coated
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/06—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of metallic material
    • C23C16/18—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of metallic material from metallo-organic compounds
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
    • C23C16/45523—Pulsed gas flow or change of composition over time
    • C23C16/45525—Atomic layer deposition [ALD]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
    • B01J2231/60—Reduction reactions, e.g. hydrogenation
    • B01J2231/64—Reductions in general of organic substrates, e.g. hydride reductions or hydrogenations
    • B01J2231/641—Hydrogenation of organic substrates, i.e. H2 or H-transfer hydrogenations, e.g. Fischer-Tropsch processes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/584—Recycling of catalysts

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Catalysts (AREA)

Abstract

The invention discloses a Pt@SiO with surface-limited domain type atomic-level dispersion 2 N-catalysts, their preparation and use, the present invention was based on Atomic Layer Deposition (ALD) technology, and the functionalization with amino groups was first reportedPorous SiO of branch 2 Nanometer flower ball is used as carrier, pt@SiO with surface limited domain type atomic level dispersion is prepared by regulating and controlling deposition parameters of ALD 2 -N catalyst, pt metal size is precisely controlled from monoatomic, clustered to nanoparticle. Wherein, the catalyst with coexisting single atom-cluster shows excellent catalytic hydrogenation activity and selectivity to p-chloronitrobenzene. The catalyst of the invention greatly improves the traditional SiO 2 The supported catalyst has the defect of easy agglomeration, the utilization rate and stability of metal atoms are greatly improved, and the synthesis strategy can be popularized to the preparation of other heterogeneous catalysts.

Description

Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof
Technical Field
The invention belongs to the technical field of atomic-level dispersed catalysts, and particularly relates to a surface-limited-domain atomic-level dispersed Pt@SiO 2 -N catalyst, its preparation method and application.
Background
The catalyst with atomic-level dispersion has ultra-high atomic utilization rate, can regulate and control the activity, selectivity and stability of the catalytic reaction while saving the consumption of metal, especially noble metal, and is widely paid attention to students at home and abroad. Common carbon materials (e.g. graphene, carbon nanotubes, C 3 N 4 Etc.) and oxide supports (e.g. reducible TiO 2 、CeO 2 Non-reducing MgO, al 2 O 3 Etc.) supported atomically dispersed catalysts have been reported and exhibit excellent catalytic performance. The atomic dispersion catalyst has great industrial application potential in the fields of industrial catalysis, enzyme catalysis and the like. SiO (SiO) 2 Has the advantages of low price, good wear resistance, high thermal stability, high chemical stability and the like, is a catalyst carrier commonly used in laboratories and industries, and has wide application in the fields of catalysis, adsorption separation, biomedicine and the like. However, because the surface groups are limited, the loaded metal particles are easy to aggregate, grow or fall off, and the loaded SiO with high dispersion, high activity and high stability is prepared 2 Catalysts remain a challenge, especially for preparing atomically dispersed supported SiO 2 The catalyst has not been reported explicitly.
SiO prepared by the traditional method 2 The supported catalyst has the defects of larger particle size, uneven distribution, easy aggregation and poor stability, and prevents the establishment of structure-activity relationship and the industrialized application thereof.
Disclosure of Invention
The invention aims to provide Pt@SiO for selective hydrogenation of p-chloronitrobenzene with high activity, high selectivity and high stability 2 Preparation of an N catalyst in which Pt metal is supported in an atomically dispersed form on an amino-functional porous SiO 2 So as to realize the free diffusion and extraction of the reaction moleculesThe metal size effect can be fully utilized to regulate and control the catalytic reaction performance while the utilization rate of metal atoms is high.
ALD is an advanced thin film and particle deposition technology, and can realize accurate regulation and control on the thickness of the thin film, the size and the dispersity of metal particles in an atomic layer, which are difficult to realize by other traditional methods. In view of the defects in the prior art, the invention fully utilizes the advantages and characteristics of ALD technology, and controls parameters such as pulse time, cycle number, deposition kinetics and the like to perform surface functionalization on SiO 2 The Pt ALD process of N obtains the surface limited domain atomic fraction Pt@SiO 2 -a catalyst of N which allows complete catalytic conversion of p-chloronitrobenzene and its derivatives and highly selective obtaining of the target product.
The invention is realized by the following technical scheme:
the first aspect of the invention provides a Pt@SiO surface-limited atomic-level dispersion 2 N catalyst in which Pt metal is supported in an atomically dispersed form on amino-functionalized porous SiO 2 Is a surface of the substrate.
As further illustration of the invention, the loading of the Pt metal is 0.1-3 wt%, and the size of the Pt metal can be precisely regulated from nano particles, clusters/atom clusters to single atoms.
As a further illustration of the present invention, the Pt metal is uniformly anchored to SiO 2 Is formed in the surface hole of the plate.
As a further illustration of the invention, the support of the catalyst is a dendritic divergent porous SiO 2 Nanospheres of size (50-900 nm), specific surface area (80-260 m) 2 /g), pore volume (0.5-2.5. 2.5 cm) 3 /g) and the pore diameter (0.3-80 and nm) are precisely adjustable.
In a second aspect, the invention provides a surface-confined atomically dispersed Pt@SiO as described in any one of the preceding 2 -a process for the preparation of an N catalyst, said process comprising the steps of:
s1: preparation of SiO by solvothermal synthesis 2 A carrier, then to the SiO 2 Surface amino functionalization grafting of carrierBranching to obtain amino-functionalized SiO 2 -an N vector; the SiO is subjected to 2 The N carrier is evenly coated on the quartz plate by ethanol and is naturally air-dried for standby;
s2: siO obtained in the step 1 is processed 2 Placing an N carrier into an ALD vacuum reaction cavity to perform Pt deposition, and controlling deposition parameters to obtain atomically dispersed Pt@SiO 2 -N surface-limited catalysts.
As a further illustration of the invention, the amino-functionalized SiO described in S1 2 The preparation process of the-N carrier specifically comprises the following steps:
dissolving triethanolamine, cetyl trimethyl ammonium bromide and sodium dodecyl sulfonate in deionized water to form a mixed solution, and stirring at 25-100deg.C for 0.5-6 h; then adding a certain concentration of ethyl orthosilicate solution into the mixed solution, and continuously stirring for 0.5-6 h; after the reaction is finished, the reaction solution is washed by alcohol, washed by water, centrifuged and dried, and then the reaction solution is cooled to 450-900 o Roasting 2-9 h under the atmosphere of C air to obtain SiO 2 A carrier;
dissolving 3-aminopropyl triethoxy silane in toluene, adding a certain amount of SiO under stirring 2 The carrier is heated to 50-100 ℃ and is continuously stirred for 12-60 h; after the reaction is finished, obtaining amino-functionalized SiO after centrifugation, alcohol washing and water washing 2 -N-carrier, then functionalizing the amino group of SiO 2 The N support was dried under vacuum at 60℃for 12 h.
The method for synthesizing SiO through solvothermal synthesis can realize 2 The carriers are prepared in batches (from gram to kilogram scale).
As a further illustration of the present invention, the deposition parameters during Pt ALD in S2 are:
the deposition temperature of the reaction cavity is controlled between 160 and 320 o C, the heating temperature of the Pt metal precursor is 45-80 o C, pulse time of 0.2-15 s, exposure time of 1-45 s, cycle number of 1-60, N 2 The flow rate of the carrier gas is 20-80 mL/min.
As a further explanation of the present invention, the precursor of Pt metal is one of (trimethyl) cyclopentadienyl platinum and platinum acetylacetonate, and the reaction gas is H 2 、O 2 O and O 3 The content of the reaction gas is 0.5-99 vol%.
As a further illustration of the present invention, the Pt ALD process adopts one of a breath hold mode and a flow mode.
The third aspect of the invention also provides the Pt@SiO surface limited domain type atomic level dispersion 2 The use of an N catalyst in the reaction of the selective hydrogenation of p-chloronitrobenzene to produce p-chloroaniline.
Compared with the prior art, the invention has the following advantages:
the invention adopts the strategy of physical and chemical co-anchoring to design and synthesize the atomic fraction catalyst with high activity and high stability. Physical means anchoring metal aspect, siO of hierarchical pore structure 2 The nano-flower ball can effectively inhibit migration, growth and falling of Pt particles; meanwhile, pt particles are limited in SiO 2 The surface confinement structure makes mass transfer of the reactants not an issue. In the aspect of anchoring metals by chemical means, the invention adopts the chemical grafting means to inert SiO 2 Performing surface amino functionalization, which will provide metal precursor anchoring and metal deposition growth sites for subsequent Pt ALD processes; further, parameters such as pulse time, exposure time, ALD dynamics and the like of the precursor are finely regulated and controlled to realize precise regulation and control on Pt size and different species proportions; the atomic fraction dispersing catalyst with high dispersion characteristic, high activity and high stability can be finally obtained by combining chemical grafting and ALD technology.
The catalyst has the advantages of accurate and controllable structure, batch preparation, simple and controllable loading capacity and size of the active components of the obtained catalyst, and excellent catalytic performance; the catalyst is applied to the reaction of preparing the p-chloroaniline by the selective hydrogenation of the p-chloronitrobenzene, can obtain very high reactivity, selectivity and stability, can effectively inhibit the occurrence of side reactions such as dechlorination, coupling and the like, improves the reaction selectivity, and is easy to separate and recycle after the reaction is finished.
Drawings
FIG. 1 is a porous SiO of example 1 of the present invention 2 Scanning electron microscope and transmission electron microscope image of the nanospheres; wherein (a) is a scanning electricA mirror image, (b) a transmission electron mirror image;
FIG. 2 is Pt in example 1 of the present invention SA @SiO 2 -high angle annular dark field scanning transmission electron microscope (HAADF-STEM) map of N catalyst;
FIG. 3 is Pt in example 2 of the present invention SA+NC @SiO 2 HAADF-STEM diagram of N catalyst;
FIG. 4 shows Pt after 4 cycles in example 2 of the present invention SA+NC @SiO 2 HAADF-STEM diagram of N catalyst;
FIG. 5 is Pt in example 3 of the present invention SA+NP @SiO 2 HAADF-STEM diagram of N catalyst;
FIG. 6 is a Pt@SiO which is not functionalized grafted with an amino group 2 HAADF-STEM diagram of catalyst.
Description of the embodiments
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1: surface-limited-domain atomic-level dispersed Pt SA @SiO 2 The preparation method of the N monoatomic catalyst specifically comprises the following steps:
(1) Porous SiO 2 Preparation of nanospheres and amino functionalization thereof: 3.48 g triethanolamine, 15.2 g hexadecyl trimethyl ammonium bromide and 3.8 g sodium dodecyl sulfonate are dissolved in 500 mL deionized water to form a mixed solution, and the mixed solution is stirred at 80 ℃ to obtain a mixture of 1 h; then adding an ethyl orthosilicate solution (145.8 g ethyl orthosilicate is dissolved in 500 mL water solution) into the mixed solution, and continuously stirring at 80 ℃ for 2 h; after the reaction is finished, obtaining a white precursor after centrifugation (12000 turns for 10 min) and alcohol washing; drying 12 h at 60 ℃; finally roasting the dried white powder at 750 ℃ to obtain 4.5 h porous SiO 2 The nanospheres are ready for use. Amino functionalization of the support: 10 mL of 3-aminopropyl triethoxysilane was dissolved in 100 mL toluene,then 1 g of the above SiO was added under stirring 2 Nanospheres, stirring 48 h at 80 ℃; after the reaction is finished, the obtained amino-functionalized SiO is subjected to centrifugation, alcohol washing and water washing 2 The N support was dried under vacuum at 60℃for 12 h.
(2) Preparation of an atomic fraction catalyst: taking 10 mg amino-functionalized SiO 2 The N carrier is coated with ethanol uniformly on a quartz plate, and after natural air drying, the quartz plate is placed in an ALD vacuum reaction cavity for Pt deposition: the pressure in the cavity was 50 Pa and the temperature in the cavity was 250 o C, heating temperature of precursor (trimethyl) cyclopentadienyl platinum is 60 o C, the reaction gas is O 3 ，N 2 The carrier gas flow rate is 50 mL/min, the pulse and exposure of (trimethyl) cyclopentadienyl platinum are respectively 0.8 s and 20 s, the circulation times are 12, and the surface limited domain atomic dispersed Pt is obtained by controlling the deposition parameters SA @SiO 2 -N catalyst, wherein the Pt loading is 0.3 wt%.
Pt obtained by the preparation process SA @SiO 2 The HAADF-STEM diagram of the N catalyst, as shown in fig. 2, shows that Pt is uniformly distributed on the support in the form of single atoms, and no Pt nanoparticles or clusters are found.
The catalyst evaluation was carried out in a batch reactor, 0.3 mmol of p-chloronitrobenzene was dissolved in ethanol, transferred to a 50 mL autoclave, 10 mg of the prepared catalyst was added to the autoclave, the air in the autoclave was replaced with hydrogen 3 times, and then the autoclave was pressurized to 0.8 Mpa and gradually warmed to 80 Mpa o Reaction 6 h was stirred magnetically. After the reaction is finished, cooling to room temperature, then decompressing, and filtering the reaction containing the catalyst through an organic filter membrane; the filtrate was analyzed by high performance gas chromatography (Thermol 1300): the conversion of p-chloronitrobenzene was about 3.5% and the selectivity of the target product p-chloroaniline was 99%.
Example 2: pt with coexisting surface-limited monoatomic clusters SA+NC @SiO 2 The preparation method of the-N catalyst specifically comprises the following steps:
(1) Porous SiO 2 Preparation of nanospheres and amino functionalization thereof: 3.48 and g triethanolamine and 15.2 and g hexadecaneDissolving trimethyl ammonium bromide and 3.8 g sodium dodecyl sulfonate in 500 mL deionized water to form a mixed solution, and stirring at 80 ℃ for 1 h; then adding an ethyl orthosilicate solution (145.8 g ethyl orthosilicate is dissolved in 500 mL water solution) into the mixed solution, and continuously stirring at 80 ℃ for 2 h; after the reaction is finished, obtaining a white precursor after centrifugation (12000 turns for 10 min) and alcohol washing; drying 12 h at 60 ℃; finally roasting the dried white powder at 750 ℃ for 6 h to obtain porous SiO 2 The nanospheres are ready for use. Functionalization of carrier amino: 10 mL of 3-aminopropyl triethoxysilane was dissolved in 100 mL toluene, and 1 g of the above SiO was added with stirring 2 Nanospheres, stirring 48 h at 80 ℃; after the reaction is finished, the obtained amino-functionalized SiO is subjected to centrifugation, alcohol washing and water washing 2 The N support was dried under vacuum at 60℃for 12 h.
(2) Preparation of an atomic fraction catalyst: taking 10 mg amino-functionalized SiO 2 The N carrier is coated with ethanol uniformly on a quartz plate, and after natural air drying for standby, the quartz plate is placed in an ALD vacuum reaction cavity for Pt deposition: the pressure in the cavity was 50 Pa and 250 o C, heating temperature of precursor (trimethyl) cyclopentadienyl platinum is 60 o C, the reaction gas is O 3 ，N 2 The carrier gas flow rate was 50 mL/min, the pulse and exposure of (trimethyl) cyclopentadienyl platinum were 0.8 s and 20 s, respectively, the cycle number was 25, and atomically dispersed Pt was obtained by controlling the deposition parameters SA+NC @SiO 2 A surface-limited catalyst, wherein the Pt loading was 0.6 wt%.
Pt obtained by the preparation process SA+NC @SiO 2 The HAADF-STEM diagram of the N catalyst, as shown in fig. 3, shows that a high density of Pt monoatoms and a small number of clusters coexist on the support, where the monoatoms still occupy an absolute number; and these clusters are composed of loose atoms, which still exhibit atomically dispersed properties.
The catalyst evaluation was carried out in a batch reactor, p-chloronitrobenzene was dissolved in ethanol and transferred to a 50 mL autoclave, 10 mg of the prepared catalyst was added to the autoclave, and the interior of the autoclave was repeatedly replaced with hydrogen gasAir is heated to 80 for 3 times o C reaction 1.5 h. Cooling to room temperature, releasing pressure, and filtering the reaction containing the catalyst through an organic filter membrane; the filtrate is analyzed by high-efficiency gas chromatography: the conversion of p-chloronitrobenzene is 99%, and the selectivity of the target product p-chloroaniline is 99%. The catalyst thus filtered was reused 4 times according to the above experimental conditions. The conversion of p-chloronitrobenzene and the selectivity of p-chloroaniline in 4 experiments are shown in the following table by gas chromatographic analysis:
experimental batch Conversion of p-chloronitrobenzene Selectivity to p-chloroaniline
1 100% 99%
2 100% 99%
3 100% 99%
4 100% 99%
As shown in the table, the catalyst is repeatedly used for 4 times, and the conversion rate of m-phenylenediamine and the yield of resorcinol are not obviously reduced; after the catalyst is repeatedly used for 4 times, the surface of the catalyst still contains high-density single atoms, which proves that the catalyst has good stability.
Pt after 4 cycles SA+NC @SiO 2 The HAADF-STEM diagram of the N catalyst, as shown in fig. 4, shows that the microstructure of the catalyst remains intact, the high density Pt single atoms are still uniformly distributed on the support, no significant aggregation is found, indicating that the catalyst has excellent stability.
Example 3: pt with coexisting surface-limited monoatomic-nanoparticle SA+NP @SiO 2 The preparation method of the-N catalyst specifically comprises the following steps:
(1) Porous SiO 2 Preparation of nanospheres and amino functionalization thereof: 3.48 g triethanolamine, 15.2 g hexadecyl trimethyl ammonium bromide and 3.8 g sodium dodecyl sulfonate are dissolved in 500 mL deionized water to form a mixed solution, and the mixed solution is stirred at 80 ℃ to obtain a mixture of 1 h; then adding an ethyl orthosilicate solution (145.8 g ethyl orthosilicate is dissolved in 500 mL water solution) into the mixed solution, and continuously stirring at 80 ℃ for 2 h; after the reaction is finished, obtaining a white precursor after centrifugation (12000 turns for 10 min) and alcohol washing; drying 12 h at 60 ℃; finally roasting the dried white powder at 750 ℃ for 6 h to obtain porous SiO 2 The nanospheres are ready for use. Functionalization of carrier amino: 10 mL of 3-aminopropyl triethoxysilane was dissolved in 100 mL toluene, and 1 g of the above SiO was added with stirring 2 Nanospheres, stirring 48 h at 80 ℃; after the reaction is finished, the obtained amino-functionalized SiO is subjected to centrifugation, alcohol washing and water washing 2 The N support was dried under vacuum at 60℃for 12 h.
(2) Preparation of an atomic fraction catalyst: taking 10 mg amino-functionalized SiO 2 The N carrier is coated with ethanol uniformly on a quartz plate, and after natural air drying, the quartz plate is placed in an ALD vacuum reaction cavity for Pt deposition: the pressure in the cavity was 50 Pa and the temperature in the cavity was 250 o C, heating temperature of precursor (trimethyl) cyclopentadienyl platinum is 60 o C, the reaction gas is O 3 ，N 2 The carrier gas flow was 50 mL/min and the pulse and exposure of (trimethyl) cyclopentadienyl platinum was 0.8 s and 20, respectivelys, the cycle number is 40, and the surface-limited domain atomic-level dispersed Pt is obtained by controlling the deposition parameters SA+NP @SiO 2 -N catalyst, wherein the Pt loading is 1.5 wt%.
Pt obtained by the preparation process SA+NP @SiO 2 The HAADF-STEM diagram of the N catalyst, as shown in fig. 5, shows a further increase in the density of single atoms, co-existing with a small amount of Pt nanoparticles on the support.
The catalyst evaluation was carried out in a batch reactor, 0.3 mmol of p-chloronitrobenzene was dissolved in ethanol, transferred to a 50 mL autoclave, 10 mg of the prepared catalyst was added to the autoclave, the air in the autoclave was replaced with hydrogen 3 times, and then the autoclave was pressurized to 0.8 Mpa and gradually warmed to 80 Mpa o Reaction 1 h was stirred magnetically. After the reaction is finished, cooling to room temperature, then decompressing, and filtering the reaction containing the catalyst through an organic filter membrane; the filtrate was analyzed by high performance gas chromatography (Thermol 1300): the conversion of p-chloronitrobenzene was 99% and the selectivity of the target product p-chloroaniline was 84%.
Comparative example 1: pt@SiO grafted by non-amino functionalization 2 The preparation method of the catalyst specifically comprises the following steps:
(1) Porous SiO 2 Preparation of nanospheres: 3.48 g triethanolamine, 15.2 g hexadecyl trimethyl ammonium bromide and 3.8 g sodium dodecyl sulfonate are dissolved in 500 mL deionized water to form a mixed solution, and the mixed solution is stirred at 80 ℃ to obtain a mixture of 1 h; then adding an ethyl orthosilicate solution (145.8 g ethyl orthosilicate is dissolved in 500 mL water solution) into the mixed solution, and continuously stirring at 80 ℃ for 2 h; after the reaction is finished, obtaining a white precursor after centrifugation (12000 turns for 10 min) and alcohol washing; drying 12 h at 60 ℃; finally roasting the dried white powder at 750 ℃ for 6 h to obtain porous SiO 2 The nanospheres are ready for use.
(2) Pt@SiO 2 And (3) preparing a catalyst: taking 10 mg of the porous SiO 2 The nanosphere carrier is coated with ethanol and uniformly coated on a quartz plate, and after natural air drying for standby, the nanosphere carrier is placed in an ALD vacuum reaction cavity for Pt deposition: the pressure in the cavity was 50 Pa and 250 o C, precursor (trimethyl) ringThe heating temperature of the pentadienyl platinum is 60 o C, the reaction gas is O 3 ，N 2 The carrier gas flow rate is 50 mL/min, the pulse and exposure of (trimethyl) cyclopentadienyl platinum are respectively 0.8 s and 20 s, the circulation times are 25, and the Pt@SiO which is not grafted by amino functionalization is obtained 2 A catalyst.
FIG. 6 is a Pt@SiO which is not functionalized grafted with an amino group 2 HAADF-STEM diagram of catalyst; from the figure, it can be seen that Pt particles are unevenly dispersed and are extremely easily detached from the carrier.
It should be noted that in this document, terms such as "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. Surface-limited-domain atomic-level dispersed Pt@SiO 2 N catalyst, characterized in that the Pt metal is supported in an atomically dispersed form on an amino-functional porous SiO 2 Is a surface of the substrate.
2. Surface confined atomically dispersed pt@sio according to claim 1 2 -N catalyst, characterized in that the Pt metal loading is 0.1-3 wt%.
3. Surface confined atomically dispersed pt@sio according to claim 1 2 N catalyst, characterized in that the Pt metal is uniformly anchored to SiO 2 Is formed in the surface hole of the plate.
4. Surface confined atomically dispersed pt@sio according to claim 1 2 N catalyst, characterized in that the support of the catalyst is a dendritic divergent porous SiO 2 Nanospheres of SiO 2 The size of the nanosphere is 50-900 nm, and the specific surface area is 80-260 m 2 /g, pore volume of 0.5-2.5 cm 3 /g, pore size of 0.3-80 and nm.
5. A surface-limited atomically dispersed pt@sio as claimed in any one of claims 1 to 4 2 -a process for the preparation of an N catalyst, characterized in that it comprises the steps of:
s1: preparation of SiO by solvothermal synthesis 2 A carrier, then to the SiO 2 The carrier is grafted with amino functionalization on the surface to obtain amino functionalized SiO 2 -an N vector; the SiO is subjected to 2 The N carrier is evenly coated on the quartz plate by ethanol and is naturally air-dried for standby;
s2: siO obtained in the step 1 is processed 2 Placing an N carrier into an ALD vacuum reaction cavity to perform Pt deposition, and controlling deposition parameters to obtain atomically dispersed Pt@SiO 2 -N surface-limited catalysts.
6. The surface confined-domain atomically dispersed pt@sio of claim 5 2 A process for the preparation of an N catalyst, characterized in that the amino-functionalized SiO of S1 2 The preparation process of the-N carrier specifically comprises the following steps:
dissolving triethanolamine, cetyl trimethyl ammonium bromide and sodium dodecyl sulfonate in deionized water to form a mixed solution, and stirring at 25-100deg.C for 0.5-6 h; then adding a certain concentration of ethyl orthosilicate solution into the mixed solution, and continuously stirring for 0.5-6 h; after the reaction is finished, the reaction solution is washed by alcohol, washed by water, centrifuged and dried, and then the reaction solution is cooled to 450-900 o Roasting 2-9 h under the atmosphere of C air to obtain SiO 2 A carrier;
dissolving 3-aminopropyl triethoxy silane in toluene, adding a certain amount of SiO under stirring 2 The carrier, thenHeating to 50-100deg.C, and stirring for 12-60 h; after the reaction is finished, obtaining amino-functionalized SiO after centrifugation, alcohol washing and water washing 2 -N-carrier, then functionalizing the amino group of SiO 2 The N support was dried under vacuum at 60℃for 12 h.
7. The surface confined-domain atomically dispersed pt@sio of claim 5 2 -N catalyst preparation method characterized in that the deposition parameters during Pt ALD in S2 are:
the deposition temperature of the reaction cavity is controlled between 160 and 320 o C, the heating temperature of the Pt metal precursor is 45-80 o C, pulse time of 0.2-15 s, exposure time of 1-45 s, cycle number of 1-60, N 2 The flow rate of the carrier gas is 20-80 mL/min.
8. The surface confined-domain atomically dispersed pt@sio of claim 5 2 The preparation method of the-N catalyst is characterized in that the precursor of Pt metal is one of (trimethyl) cyclopentadienyl platinum and platinum acetylacetonate, and the reaction gas is H 2 、O 2 O and O 3 The content of the reaction gas is 0.5-99 vol%.
9. The surface confined-domain atomically dispersed pt@sio of claim 5 2 -a method for preparing an N catalyst, characterized in that the Pt ALD process adopts one of a breath hold mode and a flow mode.
10. The surface-limited atomically dispersed pt@sio of any one of claims 1-4 2 The use of an N catalyst in the reaction of the selective hydrogenation of p-chloronitrobenzene to produce p-chloroaniline.
CN202310711695.3A 2023-06-15 2023-06-15 Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof Pending CN116651442A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310711695.3A CN116651442A (en) 2023-06-15 2023-06-15 Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310711695.3A CN116651442A (en) 2023-06-15 2023-06-15 Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof

Publications (1)

Publication Number Publication Date
CN116651442A true CN116651442A (en) 2023-08-29

Family

ID=87718857

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310711695.3A Pending CN116651442A (en) 2023-06-15 2023-06-15 Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof

Country Status (1)

Country Link
CN (1) CN116651442A (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111632596A (en) * 2020-06-15 2020-09-08 华东理工大学 High-dispersion metal-oxide bifunctional catalyst and preparation method and application thereof
US20210252486A1 (en) * 2018-06-22 2021-08-19 The Curators Of The University Of Missouri Novel method of manufacture of metal nanoparticles and metal single-atom materials on various substrates and novel compositions
CN115304489A (en) * 2022-07-06 2022-11-08 兰州大学 Method for synthesizing parachloroaniline through catalytic hydrogenation of parachloronitrobenzene
CN115770570A (en) * 2023-01-31 2023-03-10 中国科学院金属研究所 Cerium oxide loaded atomic-scale dispersed Pt catalyst and redispersion preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210252486A1 (en) * 2018-06-22 2021-08-19 The Curators Of The University Of Missouri Novel method of manufacture of metal nanoparticles and metal single-atom materials on various substrates and novel compositions
CN111632596A (en) * 2020-06-15 2020-09-08 华东理工大学 High-dispersion metal-oxide bifunctional catalyst and preparation method and application thereof
CN115304489A (en) * 2022-07-06 2022-11-08 兰州大学 Method for synthesizing parachloroaniline through catalytic hydrogenation of parachloronitrobenzene
CN115770570A (en) * 2023-01-31 2023-03-10 中国科学院金属研究所 Cerium oxide loaded atomic-scale dispersed Pt catalyst and redispersion preparation method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
JIANKANG ZHANG, ET AL: "Mechanistic Insight into the Synergy between Platinum Single Atom and Cluster Dual Active Sites Boosting Photocatalytic Hydrogen Evolution", ADVANCED MATERIALS, vol. 35, no. 25, 29 April 2023 (2023-04-29), pages 2300902 *
JUN TIAN, ET AL: "A stable rhodium single-site catalyst encapsulated within dendritic mesoporous nanochannels", NANOSCALE, vol. 10, no. 3, 6 December 2017 (2017-12-06), pages 1048 *
XUAN WANG, ET AL: "Well-dispersed Pt nanoparticles with tunable sizes on dendritic porous silica nanospheres as an artificial enzyme", JOURNAL OF ALLOYS AND COMPOUNDS, vol. 865, 21 January 2021 (2021-01-21), pages 1 - 10 *

Similar Documents

Publication Publication Date Title
Wu et al. Sophisticated construction of Au islands on Pt–Ni: an ideal trimetallic nanoframe catalyst
CN110270348B (en) Noble metal monatomic catalyst and preparation and application thereof
CN112337509B (en) MOF-based transition metal single-atom catalyst for selective hydrogenation of carbon-carbon triple bond and preparation method thereof
WO2020082410A1 (en) Supported bimetal core-shell structure catalyst and preparation method therefor
CN113457659A (en) Transition metal monoatomic nano enzyme and preparation method and application thereof
CN108525669B (en) Highly-dispersed silicon dioxide nanotube supported nickel catalyst and preparation method thereof
CN109420515B (en) Preparation method of high-dispersion supported metal catalyst
CN109317149A (en) A kind of SiO of nickel-loaded2The preparation method and application of@C core-shell material
Bolla et al. Regular arrangement of Pt nanoparticles on S-layer proteins isolated from Lactobacillus kefiri: synthesis and catalytic application
CN113275002B (en) C/MoO 2 Porous photocatalyst and preparation method and application thereof
CN116651442A (en) Surface-confined atomic-level dispersed Pt@SiO 2 -N catalyst, preparation method and application thereof
CN106693963A (en) Preparation method of novel gold nanoparticle-modified silicon dioxide nanosheet catalyst
CN115647382B (en) Preparation method of platinum nanorod and application of platinum nanorod in fuel cell catalyst
CN113600194B (en) Nanometer photocatalyst containing cobalt with different valence states, preparation method and application thereof
CN114931946A (en) Pt/C composite catalyst and preparation method and application thereof
CN115138359B (en) Supported single-atom synergistic nanoparticle bimetallic catalyst and preparation and application thereof
CN111359669B (en) Non-covalent supported GOx-Py-Co (Salen) catalyst and synthesis method thereof
CN114345346A (en) Method for preparing metal monatomic catalyst by hydrothermal method
CN114177903A (en) Method for preparing microporous material loaded monoatomic and diatomic catalyst
CN112746288A (en) Preparation method of reduced graphene oxide loaded metal monatomic catalyst
CN109550514B (en) M1/M2xPreparation method of P-type monatomic catalyst
CN113058634A (en) Fe modified-Silicalite-1 supported GaN catalyst and catalytic application thereof
CN108654679B (en) Application of supported catalyst for improving selective hydrogenation of citronellal
CN113560594A (en) Synthesis method for synthesizing intermetallic palladium-copper nanocrystals in one step and application of intermetallic palladium-copper nanocrystals
CN108772065B (en) Preparation method of core-shell type porous silicon dioxide/iron oxide nano catalyst

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination