CN113908832A - Preparation of oxygen vacancy regulated supported palladium-based catalyst and application of catalyst in polystyrene hydrogenation - Google Patents
Preparation of oxygen vacancy regulated supported palladium-based catalyst and application of catalyst in polystyrene hydrogenation Download PDFInfo
- Publication number
- CN113908832A CN113908832A CN202111326588.6A CN202111326588A CN113908832A CN 113908832 A CN113908832 A CN 113908832A CN 202111326588 A CN202111326588 A CN 202111326588A CN 113908832 A CN113908832 A CN 113908832A
- Authority
- CN
- China
- Prior art keywords
- catalyst
- palladium
- based catalyst
- oxygen vacancy
- supported palladium
- 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.)
- Granted
Links
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 title claims abstract description 96
- 239000003054 catalyst Substances 0.000 title claims abstract description 81
- 239000004793 Polystyrene Substances 0.000 title claims abstract description 47
- 229920002223 polystyrene Polymers 0.000 title claims abstract description 45
- 229910052763 palladium Inorganic materials 0.000 title claims abstract description 34
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 239000001301 oxygen Substances 0.000 title claims abstract description 33
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 33
- 238000005984 hydrogenation reaction Methods 0.000 title claims abstract description 25
- 230000001105 regulatory effect Effects 0.000 title claims abstract description 10
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- -1 polycyclohexylethylene Polymers 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 10
- 239000002184 metal Substances 0.000 claims abstract description 10
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 35
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 34
- 239000002071 nanotube Substances 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 27
- 238000000034 method Methods 0.000 claims description 19
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 claims description 18
- 238000003756 stirring Methods 0.000 claims description 17
- 239000000047 product Substances 0.000 claims description 15
- 238000001816 cooling Methods 0.000 claims description 14
- 230000007547 defect Effects 0.000 claims description 14
- 238000001035 drying Methods 0.000 claims description 13
- 238000005406 washing Methods 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 12
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 12
- 239000008367 deionised water Substances 0.000 claims description 12
- 229910021641 deionized water Inorganic materials 0.000 claims description 12
- 239000003292 glue Substances 0.000 claims description 12
- 239000004408 titanium dioxide Substances 0.000 claims description 12
- 239000002244 precipitate Substances 0.000 claims description 11
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 10
- 230000009467 reduction Effects 0.000 claims description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 9
- 238000011065 in-situ storage Methods 0.000 claims description 9
- 239000002904 solvent Substances 0.000 claims description 9
- 238000009903 catalytic hydrogenation reaction Methods 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 8
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 8
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 claims description 7
- 239000000126 substance Substances 0.000 claims description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 6
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 claims description 6
- 239000001257 hydrogen Substances 0.000 claims description 6
- 229910052739 hydrogen Inorganic materials 0.000 claims description 6
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 claims description 6
- 239000006228 supernatant Substances 0.000 claims description 5
- 238000001132 ultrasonic dispersion Methods 0.000 claims description 5
- 238000005303 weighing Methods 0.000 claims description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 4
- 239000012696 Pd precursors Substances 0.000 claims description 4
- NNBZCPXTIHJBJL-UHFFFAOYSA-N decalin Chemical compound C1CCCC2CCCCC21 NNBZCPXTIHJBJL-UHFFFAOYSA-N 0.000 claims description 4
- 239000003960 organic solvent Substances 0.000 claims description 4
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 239000000843 powder Substances 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 2
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 claims description 2
- JKDRQYIYVJVOPF-FDGPNNRMSA-L palladium(ii) acetylacetonate Chemical compound [Pd+2].C\C([O-])=C\C(C)=O.C\C([O-])=C\C(C)=O JKDRQYIYVJVOPF-FDGPNNRMSA-L 0.000 claims description 2
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 claims description 2
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims 3
- 235000019441 ethanol Nutrition 0.000 claims 2
- 125000001967 indiganyl group Chemical group [H][In]([H])[*] 0.000 claims 1
- 229920000642 polymer Polymers 0.000 abstract description 6
- 230000009286 beneficial effect Effects 0.000 abstract description 4
- 238000009792 diffusion process Methods 0.000 abstract description 3
- 230000003993 interaction Effects 0.000 abstract description 3
- 238000007210 heterogeneous catalysis Methods 0.000 abstract description 2
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000001179 sorption measurement Methods 0.000 description 4
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 2
- 238000009776 industrial production Methods 0.000 description 2
- 238000002329 infrared spectrum Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002923 metal particle Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical group C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000002638 heterogeneous catalyst Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical compound [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 239000003755 preservative agent Substances 0.000 description 1
- 230000002335 preservative effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000007342 radical addition reaction Methods 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
- 238000002371 ultraviolet--visible spectrum Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
Images
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
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/063—Titanium; Oxides or hydroxides thereof
-
- 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
- B01J23/44—Palladium
-
- 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
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F8/00—Chemical modification by after-treatment
- C08F8/04—Reduction, e.g. hydrogenation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Catalysts (AREA)
Abstract
The invention discloses preparation of an oxygen vacancy regulated supported palladium-based catalyst and application of the oxygen vacancy regulated supported palladium-based catalyst in polystyrene hydrogenation. The catalyst prepared by the invention has a one-dimensional structure, and the active metal palladium is positioned on the outer surface of the catalyst, so that the catalyst is beneficial to fully contacting polystyrene and the active metal, and the problem of low diffusion speed of polymer molecules in the conventional porous catalyst can be solved. In addition, oxygen vacancies can enhance metal-support interactions, which can be beneficial in improving catalyst stability. The supported catalyst is applied to the hydrogenation reaction of polystyrene to obtain high-quality polycyclohexylethylene, and the hydrogenation degree of the obtained product reaches up to 100 percent, so the supported catalyst has important significance for the development of heterogeneous catalysis of polystyrene.
Description
Technical Field
The invention belongs to the field of catalytic hydrogenation of high molecular unsaturated polymers, and particularly relates to preparation of an oxygen vacancy regulated supported palladium-based catalyst and application of the oxygen vacancy regulated supported palladium-based catalyst in polystyrene hydrogenation.
Background
Polystyrene (PS) is a polymer synthesized from styrene monomer by free radical addition polymerization. PS, one of the five general-purpose plastics, is a thermoplastic plastic which is currently most widely used, and is widely used in the fields of molds, food packaging, daily necessities, and the like because of its advantages such as easy processing and molding, transparency, water resistance, insulation, and the like. However, the existence of unsaturated benzene ring group in PS makes it poor in heat resistance and radiation resistance, and is easy to break, so that the comprehensive performance of PS cannot meet the requirements of high-end applications. When the unsaturated bond on the benzene ring in PS is hydrogenated by catalysis, the phenyl group with a planar structure is converted into the cyclohexane group with a chair structure, and Polycyclohexylethylene (PCHE) with more excellent physicochemical properties can be obtained. Compared with PS, the PCHE not only retains the high transparency of PS, but also greatly improves the properties of heat resistance, ultraviolet light resistance, oxidation resistance, ozone resistance, chemical corrosion resistance, mechanical properties and the like.
The PS hydrogenation reaction reported at present is carried out in a heterogeneous catalysis system, and the system has the advantages of easy separation and recovery of the catalyst, almost no metal component residue in the polymer and the like. The catalyst mainly comprises macroporous Pd/SiO2Catalysts, Pd/CNTs catalysts (D.Pan, G.Shi, T.Zhang, P.Yuan, Y.Fan, X.Bao, Journal of Materials Chemistry A, 2013, 1, 9597-. However, the loading of active components of these PS hydrogenation catalysts is high (-5 wt.%), the interaction between the noble metal and the support is weak, and the activity and reusability of the catalysts need to be further improved.
TiO2The strong interaction exists between the material and the noble metal carrier, the stability of the metal particles on the carrier can be improved, and the TiO2Oxygen vacancy defects are easily formed on the surface, and the method can be used for regulating and controlling the properties of active metal particle size, dispersity, electronic state and the like. Furthermore, TiO2The Nanotube (TNT) structure has a large external specific surface area, is helpful for dispersing active metals, and can solve the problem of slow diffusion rate of polymers in a solvent. However, no TiO is currently available2The nanotube is used as a carrier to prepare a noble metal catalyst and is used for the research of PS catalytic hydrogenation. In addition, no studies have been reported on optimizing the catalyst performance by reducing and regulating the properties of the palladium active metal only by oxygen vacancy defects on the surface of the carrier without using a reducing agent. Thus, the present invention utilizes TiO2The structure and property characteristics of the nano tube are that the Pd/TiO with high activity is prepared by innovatively using an oxygen vacancy in-situ reduction method2The heterogeneous catalyst has very important significance and use value for the production of PCHE products with high added value by using the supported catalyst.
Disclosure of Invention
The invention aims to provide a supported catalyst prepared by in-situ reduction of Pd through oxygen vacancies on the surface of a carrier and a preparation method thereof, and the supported catalyst can be applied to hydrogenation reaction of polystyrene.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a supported palladium-based catalyst regulated by oxygen vacancies comprises the steps of carrying out in-situ reduction on metallic palladium by oxygen vacancy defects on the surface of a titanium dioxide nanotube of a carrier to prepare a supported palladium-based catalyst Pd/TNTs; which comprises the following steps:
(1) preparing the titanic acid nanotube:
adding TiO into the mixture2Adding the powder into a container filled with 15M sodium hydroxide solution, stirring and dispersing, transferring the obtained mixture into a stainless steel reaction kettle filled with a polytetrafluoroethylene lining, and reacting for 72 hours at 150 ℃; cooling to room temperature after reaction, removing supernatant, washing the obtained white precipitate with deionized water repeatedly, adding 0.1M dilute hydrochloric acid solution, ultrasonic dispersing and stirring, removingWashing the supernatant for 1-3 times; finally, washing the precipitate for multiple times by using deionized water, and drying the precipitate in a drying oven at room temperature in vacuum to obtain a one-dimensional titanic acid nanotube;
(2) preparing oxygen vacancy defects on the surface of titanium oxide:
placing the one-dimensional titanic acid nano-tube prepared in the step (1) in a container filled with Ar/H2Reducing at the high temperature of 800 ℃ for 1-5 hours in a tube furnace of mixed gas (95: 5, v/v) to obtain the titanium dioxide nanotube with oxygen vacancy defect on the surface;
(3) preparing a Pd/TNTs catalyst by an in-situ reduction method:
taking 1-1.5 g of the titanium dioxide nanotube with oxygen vacancy defect on the surface prepared in the step (2), adding 40-80 ml of solvent A, and performing ultrasonic dispersion to prepare solution B; dissolving a palladium precursor by using a solvent C to obtain a solution D; placing the solution B in a constant-temperature oil bath at the temperature of 30-80 ℃ for stirring, then slowly adding the solution D and reacting for 12-24 h; and after the reaction is finished, cooling to room temperature, centrifugally separating the mixture, washing for 1-3 times by using 50vol% ethanol solution, centrifuging again, and drying the obtained precipitate in an oven to obtain the supported palladium-based catalyst Pd/TNTs, wherein the supported amount of palladium is 0.1-10 wt.% (preferably 0.5-5 wt.%).
In the step (3), the solvent A is one or more of deionized water, acetone, formaldehyde and ethylene glycol. The palladium precursor is one or more of palladium acetylacetonate, palladium acetate, palladium chloride and palladium nitrate. The solvent C is any one of ethylene glycol, dichloromethane and acetone.
The supported palladium-based catalyst prepared by the method can be used for catalytic hydrogenation of Polystyrene (PS) to prepare Polycyclohexylethylene (PCHE). The application method specifically comprises the following steps: weighing PS with a certain mass, dissolving the PS in 70ml of organic solvent to prepare glue solution with the mass fraction of 2-10 wt.%, adding the glue solution and the supported palladium-based catalyst into a high-pressure reaction kettle, carrying out hydrogenation reaction for 3-9h under the conditions of 70-150 ℃, the hydrogen pressure of 3-5MPa and the stirring speed of 300-1000rpm, cooling the substance obtained by the reaction to room temperature, centrifuging, extracting with ethanol, and evaporating to remove the ethanol to obtain a hydrogenation product PCHE; and recovering the catalyst after reaction for later use.
The mass of the supported palladium-based catalyst used is 0.5 to 10 times the mass of the PS.
The organic solvent is one or more of cyclohexane, decahydronaphthalene and tetrahydrofuran.
The invention has the beneficial effects that:
(1) the Pd/TNTs prepared by the method is of a one-dimensional structure, and the active metal is positioned on the outer surface of the carrier, so that the PS can be in full contact with the active metal, and the diffusion limitation of polymer molecules is eliminated.
(2) The invention anchors and reduces the metal active component ions by utilizing the surface defects of the carrier, can improve the dispersity of the carrier, realizes the effective control of the properties of the active metal, and is beneficial to improving the activity of the catalyst.
(3) The catalyst preparation process is suitable for industrial production, the catalyst has excellent hydrogenation performance when being applied to polystyrene hydrogenation, and the catalyst can be recycled in a centrifugal separation recovery mode, so that the industrial production cost can be reduced to a certain extent.
Drawings
FIG. 1 is an SEM image (a), a TEM image (b) and a size distribution diagram (c) of Pd particles on the Pd/TNTs catalyst prepared in example 1;
FIG. 2 is an infrared spectrum of a PS hydrogenation product prepared in examples and comparative examples.
Detailed Description
In order to clearly and clearly show the technical contents, characteristics, effects and the like of the invention, the invention will be more exactly and comprehensively described by the following embodiments, but the invention is not to be construed as limiting the implementable scope of the invention.
Example 1
(1) Preparing the titanic acid nanotube:
8 g of TiO are taken2Adding the powder particles into a beaker filled with 70ml of 15M sodium hydroxide solution, stirring and dispersing, transferring the obtained mixture into a stainless steel reaction kettle filled with 100ml of polytetrafluoroethylene lining, and reacting for 72 hours at 150 ℃; cooling to room temperature after the reaction is finished, and removingSupernatant, repeatedly washing the obtained white precipitate with deionized water until the pH is =7-8, then adding 500 ml of dilute hydrochloric acid solution with the concentration of 0.1M, ultrasonically dispersing and stirring for 8 h, and removing the supernatant; repeating the steps of washing with deionized water and dispersing with dilute hydrochloric acid solution for 3 times; finally, washing the obtained product for multiple times by using deionized water until the pH of an eluate is =7-8, and drying the obtained product in a drying oven at the room temperature in vacuum to obtain a one-dimensional titanic acid nanotube;
(2) preparing oxygen vacancy defects on the surface of titanium oxide:
placing the prepared titanic acid nano-tube in a gas filled with Ar/H2Heating to 450 ℃ at the speed of 5 ℃/min in a reducing tube furnace of mixed gas (95: 5, v/v, the gas flow rate is 60 ml/min) and keeping for 2h to obtain the titanium dioxide nanotube with oxygen vacancy defects on the surface;
(3) preparing a Pd/TNTs catalyst by an in-situ reduction method:
taking 1.5 g of the titanium dioxide nanotube prepared in the step, adding 50ml of deionized water, and performing ultrasonic dispersion for 2 hours to prepare a solution A; 0.0971 g of palladium acetate is dissolved in 5 ml of dichloromethane to obtain a solution B; placing the solution A in a constant-temperature oil bath at 60 ℃, stirring at the rotating speed of 450 rpm, and reacting for 24 hours after slowly adding the solution B; after the reaction is finished, cooling to room temperature, centrifuging the mixture, washing for 2 times by using 50vol% ethanol solution, centrifuging again, and drying the obtained precipitate in a vacuum oven at 60 ℃ to obtain the Pd/TNTs catalyst with the Pd loading of 3 wt.%.
(4) Catalytic hydrogenation of polystyrene:
dissolving 1.1153g of PS in 70ml of cyclohexane to prepare PS glue solution with the mass fraction of 2 wt.%, weighing 1.0024 g of Pd/TNTs catalyst, adding the glue solution and the catalyst into a high-pressure reaction kettle, and reacting for 8 hours under the conditions of 150 ℃, the hydrogen pressure of 5MPa and the stirring speed of 1000 rpm; cooling the obtained substance to room temperature and centrifuging, then extracting the hydrogenation product by ethanol, putting the product in a drying oven to evaporate the ethanol to obtain the polycyclohexylethylene, and recovering the catalyst after reaction for later use. The degree of hydrogenation of the catalyst to polystyrene under the condition is 100 percent by utilizing ultraviolet-visible spectrum analysis.
Example 2
The titania nanotube carrier was prepared in the same manner as in the steps (1) and (2) of example 1.
(3) Preparing a Pd/TNTs catalyst by an in-situ reduction method:
taking 1.5 g of the titanium dioxide nanotube prepared in the step, adding 50ml of deionized water, and performing ultrasonic dispersion for 2 hours to prepare a solution A; 0.0319 g of palladium acetate is dissolved in 5 ml of dichloromethane to obtain a solution B; placing the solution A in a constant-temperature oil bath at 60 ℃, stirring at the rotating speed of 350 rpm, and reacting for 24 hours after slowly adding the solution B; after the reaction is finished, cooling to room temperature, centrifuging the mixture, washing for 2 times by using 50vol% ethanol solution, centrifuging again, and drying the obtained precipitate in a vacuum oven at 60 ℃ to obtain the Pd/TNTs catalyst with the Pd loading of 1 wt.%.
(4) Catalytic hydrogenation of polystyrene:
dissolving 1.1141g of PS in 70ml of cyclohexane to prepare PS glue solution with the mass fraction of 2 wt.%, weighing 1.0026 g of Pd/TNTs catalyst, adding the glue solution and the catalyst into a high-pressure reaction kettle, and reacting for 8 hours at the conditions of 150 ℃, the hydrogen pressure of 4 MPa and the stirring speed of 1000 rpm; cooling the obtained substance to room temperature and centrifuging, then extracting the hydrogenation product by ethanol, putting the product in a drying oven to evaporate the ethanol to obtain the polycyclohexylethylene, and recovering the catalyst after reaction for later use. The degree of hydrogenation of polystyrene by the catalyst under the condition is 98.7%.
Comparative example 1
The titania nanotube carrier was prepared in the same manner as in the steps (1) and (2) of example 1.
(3) Preparing a Pd/TNTs catalyst by an isometric impregnation method:
taking 1.5 g of the titanium dioxide nanotubes prepared in the step, and uniformly dispersing the titanium dioxide nanotubes at the bottom of a 250ml beaker; 0.0316 g palladium acetate is dissolved in 2.4 ml dichloromethane to obtain solution A; uniformly dropwise adding the solution A into a beaker filled with titanium dioxide nanotubes, covering with a preservative film after dropwise adding is finished, standing for 24h, and vacuum drying at 60 ℃ for 24 h; then placing the sample in the presence of Ar/H2Reducing the mixed gas (95: 5, v/v, gas flow rate 60 ml/min) in a tube furnace at 5 ℃/minThe catalyst was heated to 150 ℃ for 2h to obtain a Pd/TNTs catalyst with a palladium loading of 1 wt.%.
(4) Catalytic hydrogenation reaction of polystyrene:
dissolving 1.1155g of PS in 70ml of cyclohexane to prepare PS glue solution with the mass fraction of 2 wt.%, weighing 1.0006 g of Pd/TNTs catalyst, adding the glue solution and the catalyst into a high-pressure reaction kettle, and reacting for 8 hours under the conditions of 150 ℃, the hydrogen pressure of 4 MPa and the stirring speed of 1000 rpm; cooling the obtained substance to room temperature and centrifuging, then extracting the hydrogenation product by ethanol, putting the product in a drying oven to evaporate the ethanol to obtain the polycyclohexylethylene, and recovering the catalyst after reaction for later use. The degree of hydrogenation of polystyrene by the catalyst under the condition is 92.7 percent.
Comparative example 2
The same method as in step (1) of example 1 was used to prepare titanic acid nanotubes.
(2) Preparing a titanium oxide nanotube carrier without oxygen vacancy defects:
placing the prepared titanic acid nanotube in a muffle furnace, and roasting for 2h at 450 ℃ in the air atmosphere to obtain a TNTs carrier without oxygen vacancies;
(3) preparing a Pd/TNTs catalyst by an in-situ reduction method:
taking 1.5 g of the TNTs carrier without oxygen vacancies prepared in the step, adding 50ml of deionized water, and performing ultrasonic dispersion for 2 hours to prepare a solution A; 0.0316 g palladium acetate is dissolved in 5 ml dichloromethane to obtain solution B; placing the solution A in a constant-temperature oil bath at 60 ℃, stirring at the rotating speed of 350 rpm, and reacting for 24 hours after slowly adding the solution B; after the reaction is finished, cooling to room temperature, centrifuging the mixture, washing for 2 times by using 50vol% ethanol solution, centrifuging again, and drying the obtained precipitate in a vacuum oven at 60 ℃ to obtain the Pd/TNTs catalyst without oxygen vacancy, wherein the palladium loading capacity is 1 wt.%.
(4) Catalytic hydrogenation reaction of polystyrene:
1.1132g of PS is dissolved in 70ml of cyclohexane to prepare PS glue solution with the mass fraction of 2 wt.%, 1.0005 g of Pd/TNTs catalyst is weighed, the glue solution and the catalyst are added into a high-pressure reaction kettle together, and the reaction is carried out for 8 hours under the conditions of 150 ℃, the hydrogen pressure of 4 MPa and the stirring speed of 1000 rpm; cooling the obtained substance to room temperature and centrifuging, then extracting the hydrogenation product by ethanol, putting the product in a drying oven to evaporate the ethanol to obtain the polycyclohexylethylene, and recovering the catalyst after reaction for later use. The degree of hydrogenation of polystyrene by the catalyst under these conditions was 78.8%.
FIG. 2 is an infrared spectrum of a PS hydrogenation product obtained in examples and comparative examples. As can be seen from the figure, PS starting materials 1492 and 1600 cm-1The characteristic peak is a stretching vibration absorption peak of a benzene ring framework; 3024 cm-1The characteristic peak is the C-H stretching vibration absorption peak on the benzene ring; 2854 and 2922 cm-1is-CH2Upper C-H stretching vibration adsorption peak. In the samples of comparative examples 1 and 2, the characteristic adsorption peak of the benzene ring still exists, which indicates that part of the benzene ring is not hydrogenated; in the samples of examples 1 and 2, the characteristic adsorption peak of the benzene ring was completely disappeared, and-CH2The characteristic adsorption peak of-is significantly increased, indicating that the phenyl group has been completely hydrogenated to form a cyclohexane group.
The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.
Claims (10)
1. A preparation method of an oxygen vacancy regulated supported palladium-based catalyst is characterized by comprising the following steps: reducing metal palladium in situ through oxygen vacancy defects on the surface of a titanium dioxide nanotube of a carrier to prepare a supported palladium-based catalyst Pd/TNTs; which comprises the following steps:
(1) preparing the titanic acid nanotube:
adding TiO into the mixture2Adding the powder into 15M sodium hydroxide solution, stirring and dispersing, transferring the obtained mixture into a stainless steel reaction kettle with a polytetrafluoroethylene lining, and reacting for 72 hours at 150 ℃; cooling to room temperature after the reaction is finished, removing supernatant, repeatedly washing the obtained white precipitate with deionized water, then adding 0.1M dilute hydrochloric acid solution, ultrasonically dispersing and stirring, removing supernatant, and repeatedly washing for 1-3 times; finally, washing the precipitate with deionized water for many times, and performing vacuum treatmentDrying at room temperature to obtain a one-dimensional titanic acid nanotube;
(2) preparing oxygen vacancy defects on the surface of titanium oxide:
placing the one-dimensional titanic acid nano-tube prepared in the step (1) in a container filled with Ar/H2In a tube furnace of mixed gas, titanium dioxide nanotubes with oxygen vacancy defects on the surface are obtained through high-temperature reduction;
(3) preparing a Pd/TNTs catalyst by an in-situ reduction method:
taking 1-1.5 g of the titanium dioxide nanotube with oxygen vacancy defect on the surface prepared in the step (2), adding 40-80 ml of solvent A, and performing ultrasonic dispersion to prepare solution B; dissolving a palladium precursor by using a solvent C to obtain a solution D; placing the solution B in a constant-temperature oil bath at a certain temperature, stirring, slowly adding the solution D, and reacting for 12-24 h; and after the reaction is finished, cooling to room temperature, centrifugally separating the mixture, washing for 1-3 times by using 50vol% ethanol solution, centrifuging again, and drying the obtained precipitate in an oven to obtain the supported palladium-based catalyst Pd/TNTs, wherein the loading amount of palladium is 0.1-10 wt.%.
2. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: Ar/H in the step (2)2Ar and H in mixed gas2The volume percentage ratio of (a) to (b) is 95: 5.
3. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: the temperature of the high-temperature reduction in the step (2) is 200-800 ℃, and the time is 1-5 hours.
4. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: in the step (3), the solvent A is one or more of deionized water, cyclohexane, tetrahydrofuran, acetone, toluene and ethylene glycol.
5. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: in the step (3), the palladium precursor is one or more of palladium acetylacetonate, palladium acetate, palladium chloride and palladium nitrate.
6. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: in the step (3), the solvent C is any one of ethylene glycol, dichloromethane and acetone.
7. The method of preparing an oxygen vacancy-modulated supported palladium-based catalyst of claim 1, wherein: the reaction temperature used in step (3) is 30-80 ℃.
8. Use of a supported palladium-based catalyst prepared according to any one of claims 1 to 7, wherein: the supported palladium-based catalyst is used for the catalytic hydrogenation of polystyrene to prepare the polycyclohexylethylene.
9. Use of a supported palladium-based catalyst according to claim 8, characterized in that: the application method specifically comprises the following steps: weighing polystyrene with a certain mass, dissolving the polystyrene in 70ml of organic solvent to prepare a glue solution with the mass fraction of 2-10 wt.%, adding the glue solution and the supported palladium-based catalyst into a high-pressure reaction kettle, carrying out hydrogenation reaction for 3-9h under the conditions of 70-150 ℃, the hydrogen pressure of 3-5MPa and the stirring speed of 300-1000rpm, cooling the substance obtained by the reaction to room temperature, centrifuging, extracting with absolute ethyl alcohol, and evaporating to remove the ethyl alcohol to obtain a hydrogenation product, namely polycyclohexylethylene; and recovering the catalyst after reaction for later use.
10. Use of a supported palladium-based catalyst according to claim 9, characterized in that: the mass of the used supported palladium-based catalyst is 0.1-1 time of that of the polystyrene; the organic solvent is one or more of cyclohexane, decahydronaphthalene and tetrahydrofuran.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111326588.6A CN113908832B (en) | 2021-11-10 | 2021-11-10 | Preparation of supported palladium-based catalyst regulated by oxygen vacancy and application of supported palladium-based catalyst in polystyrene hydrogenation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111326588.6A CN113908832B (en) | 2021-11-10 | 2021-11-10 | Preparation of supported palladium-based catalyst regulated by oxygen vacancy and application of supported palladium-based catalyst in polystyrene hydrogenation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113908832A true CN113908832A (en) | 2022-01-11 |
| CN113908832B CN113908832B (en) | 2023-04-14 |
Family
ID=79246060
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111326588.6A Active CN113908832B (en) | 2021-11-10 | 2021-11-10 | Preparation of supported palladium-based catalyst regulated by oxygen vacancy and application of supported palladium-based catalyst in polystyrene hydrogenation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113908832B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116273125A (en) * | 2023-03-23 | 2023-06-23 | 福州大学 | Nanometer flake Pd-based catalyst and application thereof in NBR catalytic hydrogenation |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102516422A (en) * | 2011-11-23 | 2012-06-27 | 华东理工大学 | Preparation method for homopolymer or copolymer of cyclohexyl ethylene and catalyst |
| US20180290949A1 (en) * | 2016-05-23 | 2018-10-11 | Petrochina Company Limited | Palladium-Based Supported Hydrogenation Catalyst, And Preparation Method And Application Thereof |
| CN111054333A (en) * | 2020-02-14 | 2020-04-24 | 郑州轻工业大学 | Hydrotalcite-supported palladium catalyst for preparing styrene by selective hydrogenation of phenylacetylene, and preparation method and application thereof |
| CN112871199A (en) * | 2021-02-27 | 2021-06-01 | 福州大学 | Heterogeneous supported hydrogenation catalyst, preparation method thereof and application thereof in preparation of polycyclohexylethylene through hydrogenation |
| CN113522258A (en) * | 2020-04-21 | 2021-10-22 | 中国科学院广州能源研究所 | Preparation method of catalyst for efficient photocatalytic oxidation of VOCs (volatile organic compounds) |
-
2021
- 2021-11-10 CN CN202111326588.6A patent/CN113908832B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102516422A (en) * | 2011-11-23 | 2012-06-27 | 华东理工大学 | Preparation method for homopolymer or copolymer of cyclohexyl ethylene and catalyst |
| US20180290949A1 (en) * | 2016-05-23 | 2018-10-11 | Petrochina Company Limited | Palladium-Based Supported Hydrogenation Catalyst, And Preparation Method And Application Thereof |
| CN111054333A (en) * | 2020-02-14 | 2020-04-24 | 郑州轻工业大学 | Hydrotalcite-supported palladium catalyst for preparing styrene by selective hydrogenation of phenylacetylene, and preparation method and application thereof |
| CN113522258A (en) * | 2020-04-21 | 2021-10-22 | 中国科学院广州能源研究所 | Preparation method of catalyst for efficient photocatalytic oxidation of VOCs (volatile organic compounds) |
| CN112871199A (en) * | 2021-02-27 | 2021-06-01 | 福州大学 | Heterogeneous supported hydrogenation catalyst, preparation method thereof and application thereof in preparation of polycyclohexylethylene through hydrogenation |
Non-Patent Citations (3)
| Title |
|---|
| KAI-YUE HAN ET AL.: "Hydrogenation of commercial polystyrene on Pd/TiO2 monolithic ceramic foam catalysts: catalytic performance and enhanced internal mass transfer", 《REAC KINET MECH CAT》 * |
| QINGQING YUAN ET AL.: "Room temperature hydrogenation of furfuryl alcohol by Pd/titanate Nanotube", 《APPLIED CATALYSIS A: GENERAL》 * |
| XIAOYANG PAN ET AL.: "Efficient Thermal- and Photocatalyst of Pd Nanoparticles on TiO2 Achieved by an Oxygen Vacancies Promoted Synthesis Strategy", 《APPLIED MATERIALS ＆ INTERFACES》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116273125A (en) * | 2023-03-23 | 2023-06-23 | 福州大学 | Nanometer flake Pd-based catalyst and application thereof in NBR catalytic hydrogenation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113908832B (en) | 2023-04-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10160659B2 (en) | Titanium-dioxide-based double-layer hollow material, preparation method thereof, and application thereof in photocatalytic treatment of hydrogen sulfide | |
| CN108404987B (en) | Method for improving catalytic efficiency of nanoparticle @ MOFs material | |
| CN110560170B (en) | Pd @ MOF material, preparation method thereof and application thereof in biphenyl preparation | |
| Keshipour et al. | Nanocomposite of hydrophobic cellulose aerogel/graphene quantum dot/Pd: Synthesis, characterization, and catalytic application | |
| CN104549368A (en) | Preparation method of load bimetal type Cu-Pt/TiO2-NBs catalyst and application | |
| CN108067306B (en) | Pt/ZIF-8@ Al2O3Preparation method of catalyst and application of catalyst in catalytic hydrogenation reaction | |
| CN113943488B (en) | Composite material based on polytetrafluoroethylene-coated MOFs material and preparation method thereof | |
| CN113908832B (en) | Preparation of supported palladium-based catalyst regulated by oxygen vacancy and application of supported palladium-based catalyst in polystyrene hydrogenation | |
| CN110152654B (en) | Ordered mesoporous carbon-TiO 2 Composite material supported palladium catalyst, preparation method and application thereof | |
| CN104549244B (en) | A kind of rhodium nanocatalyst and preparation method and application | |
| CN108014789A (en) | A kind of loaded catalyst for the poly- cyclohexyl. vinyl of polystyrene Hydrogenation and preparation method thereof | |
| CN112023887B (en) | Preparation method of TNT @ Cu-BTC composite adsorbent and application of TNT @ Cu-BTC composite adsorbent in cyclohexane adsorption | |
| CN105618095A (en) | Porous nano-SiC loaded platinum catalyst as well as preparation and application thereof in selective hydrogenation reaction of Alpha-Beta-unsaturated aldehyde | |
| CN112108175A (en) | Preparation method of aromatic olefin | |
| CN107952431B (en) | Porous carbon @ Pd-Al2O3@ mesoporous TiO2Microspherical catalyst and preparation and application thereof | |
| CN106669737B (en) | A kind of carbon/palladium-cobalt heterogeneous catalyst preparation method of magnetic core-shell structure | |
| CN111569869B (en) | Preparation method and application of high-dispersion supported palladium-based catalyst | |
| CN109317178A (en) | A kind of loaded catalyst and preparation method thereof adding hydrogen preparation hydrogenated styrene-butadiene rubber for heterogeneous solution | |
| CN111389398B (en) | Preparation method of hierarchical hollow silica confinement cuprous oxide visible-light-driven photocatalyst | |
| JP2009213993A (en) | Polymer supported gold cluster catalyst for oxidation reaction and manufacturing method of carbonyl compound using it | |
| CN110433858B (en) | Ag/PANI/graphene composite photocatalyst, and preparation method and application thereof | |
| CN111151301B (en) | Bifunctional heterogeneous Pd @ MIL-101@ SGO composite material and preparation method and application thereof | |
| Sun et al. | Mesoscale Organization of Flower‐Like La2O2CO3and La2O3 Microspheres | |
| CN112871199A (en) | Heterogeneous supported hydrogenation catalyst, preparation method thereof and application thereof in preparation of polycyclohexylethylene through hydrogenation | |
| CN101934238B (en) | Preparation method of ethylene epoxidized silver 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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |