CN111054404B - Preparation method of flaky hydroxyapatite carrier and supported nano-silver catalyst - Google Patents
Preparation method of flaky hydroxyapatite carrier and supported nano-silver catalyst Download PDFInfo
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- CN111054404B CN111054404B CN202010017130.1A CN202010017130A CN111054404B CN 111054404 B CN111054404 B CN 111054404B CN 202010017130 A CN202010017130 A CN 202010017130A CN 111054404 B CN111054404 B CN 111054404B
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- 229910052588 hydroxylapatite Inorganic materials 0.000 title claims abstract description 91
- XYJRXVWERLGGKC-UHFFFAOYSA-D pentacalcium;hydroxide;triphosphate Chemical compound [OH-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O XYJRXVWERLGGKC-UHFFFAOYSA-D 0.000 title claims abstract description 91
- 239000003054 catalyst Substances 0.000 title claims abstract description 58
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 title claims abstract description 29
- 238000002360 preparation method Methods 0.000 title claims abstract description 22
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 48
- 238000000034 method Methods 0.000 claims abstract description 23
- 238000006243 chemical reaction Methods 0.000 claims abstract description 15
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 35
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical group [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 239000000243 solution Substances 0.000 claims description 26
- 239000002244 precipitate Substances 0.000 claims description 23
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 16
- ZCCIPPOKBCJFDN-UHFFFAOYSA-N calcium nitrate Chemical group [Ca+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ZCCIPPOKBCJFDN-UHFFFAOYSA-N 0.000 claims description 16
- 159000000007 calcium salts Chemical class 0.000 claims description 13
- 239000008139 complexing agent Substances 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- 230000003197 catalytic effect Effects 0.000 claims description 11
- 238000005406 washing Methods 0.000 claims description 11
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 10
- 239000004202 carbamide Substances 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 10
- -1 polytetrafluoroethylene Polymers 0.000 claims description 10
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 10
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 10
- 229910001220 stainless steel Inorganic materials 0.000 claims description 10
- 239000010935 stainless steel Substances 0.000 claims description 10
- 238000003756 stirring Methods 0.000 claims description 10
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims description 9
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 claims description 9
- 239000002904 solvent Substances 0.000 claims description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 8
- MNNHAPBLZZVQHP-UHFFFAOYSA-N diammonium hydrogen phosphate Chemical group [NH4+].[NH4+].OP([O-])([O-])=O MNNHAPBLZZVQHP-UHFFFAOYSA-N 0.000 claims description 8
- 229910000388 diammonium phosphate Inorganic materials 0.000 claims description 8
- 235000019838 diammonium phosphate Nutrition 0.000 claims description 8
- 229910052739 hydrogen Inorganic materials 0.000 claims description 8
- 239000001257 hydrogen Substances 0.000 claims description 8
- 238000007254 oxidation reaction Methods 0.000 claims description 8
- 239000011259 mixed solution Substances 0.000 claims description 7
- 230000007935 neutral effect Effects 0.000 claims description 7
- NBIIXXVUZAFLBC-UHFFFAOYSA-L Phosphate ion(2-) Chemical compound OP([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-L 0.000 claims description 6
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 4
- 239000012298 atmosphere Substances 0.000 claims description 4
- 239000001110 calcium chloride Substances 0.000 claims description 4
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 4
- BNIILDVGGAEEIG-UHFFFAOYSA-L disodium hydrogen phosphate Chemical compound [Na+].[Na+].OP([O-])([O-])=O BNIILDVGGAEEIG-UHFFFAOYSA-L 0.000 claims description 4
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 239000012716 precipitator Substances 0.000 claims description 4
- 239000000047 product Substances 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- 239000008367 deionised water Substances 0.000 claims description 3
- 229910021641 deionized water Inorganic materials 0.000 claims description 3
- 239000012266 salt solution Substances 0.000 claims description 3
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical class OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims 1
- 235000019441 ethanol Nutrition 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 11
- 239000002105 nanoparticle Substances 0.000 abstract description 6
- 239000006185 dispersion Substances 0.000 abstract description 4
- 229910052709 silver Inorganic materials 0.000 abstract description 4
- 125000002887 hydroxy group Chemical group [H]O* 0.000 abstract description 3
- 238000005470 impregnation Methods 0.000 abstract description 3
- 238000011065 in-situ storage Methods 0.000 abstract description 3
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 239000004332 silver Substances 0.000 abstract description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 13
- 239000002135 nanosheet Substances 0.000 description 11
- 239000000463 material Substances 0.000 description 9
- 238000003917 TEM image Methods 0.000 description 8
- 238000006555 catalytic reaction Methods 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 239000011575 calcium Substances 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 4
- 101710134784 Agnoprotein Proteins 0.000 description 3
- 241000446313 Lamella Species 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 3
- 238000000975 co-precipitation Methods 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 239000002064 nanoplatelet Substances 0.000 description 3
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000000376 reactant Substances 0.000 description 3
- 238000003980 solgel method Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000000634 powder X-ray diffraction Methods 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- 230000005476 size effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910014497 Ca10(PO4)6(OH)2 Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 238000010574 gas phase reaction Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000010335 hydrothermal treatment Methods 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000000851 scanning transmission electron micrograph Methods 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000013112 stability test Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000002076 thermal analysis method Methods 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
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- 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
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/14—Phosphorus; Compounds thereof
- B01J27/16—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr
- B01J27/18—Phosphorus; Compounds thereof containing oxygen, i.e. acids, anhydrides and their derivates with N, S, B or halogens without carriers or on carriers based on C, Si, Al or Zr; also salts of Si, Al and Zr with metals other than Al or Zr
- B01J27/1802—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates
- B01J27/1817—Salts or mixtures of anhydrides with compounds of other metals than V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, e.g. phosphates, thiophosphates with copper, silver or gold
-
- 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
- B01J35/394—Metal dispersion value, e.g. percentage or fraction
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/50—Carbon dioxide
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- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
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- Inorganic Chemistry (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a preparation method of a flaky hydroxyapatite carrier and a supported nano-silver catalyst, wherein the preparation method of the flaky hydroxyapatite carrier comprises the following steps: the method is characterized in that a hydrothermal reaction is utilized, a sheet-shaped Hydroxyapatite (HAP) carrier is prepared in one step by an in-situ growth method, the size and thickness of a HAP sheet layer are accurately regulated and controlled by adding citric acid and matching with proper reaction temperature, and the hydroxyapatite carrier with a stable structure is further prepared and obtained; in the preparation method of the supported nano-silver catalyst, hydroxyapatite with a two-dimensional sheet structure is used as a carrier, the supported nano-silver catalyst is prepared by an impregnation method, and the dispersion degree and the thermal stability of active component Ag nano-particles are obviously improved by means of the 'confinement effect' of the hydroxyapatite carrier and the 'protection effect' of hydroxyl on the surface of the carrier on the silver (Ag) nano-particles.
Description
Technical Field
The invention relates to the technical field of catalyst preparation, in particular to a preparation method of a flaky hydroxyapatite carrier and a supported nano-silver catalyst.
Background
In the heterogeneous reaction process of CO catalytic oxidation, the commonly used catalyst is a noble metal catalyst, which mainly comprises: platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), gold (Au), iridium (Ir), etc., and silver (Ag) has also been attempted as a catalyst. However, both the noble metal catalyst and the Ag catalyst are supported on a carrier.
Hydroxyapatite (HAP) molecular formula is Ca 10 (PO 4 ) 6 (OH) 2 The composition and structure of the material are such that the material has strong ion-exchange properties and the acidity or basicity of the material can be adjusted by adjusting the ratio of calcium to phosphorus, as shown in the tableThe abundant hydroxyl groups enable hydroxyapatite to be modified by other functional groups, and the hydroxyapatite is a carrier frequently selected when people prepare the supported nano metal catalyst. However, the hydroxyapatite is usually prepared by a coprecipitation method and a sol-gel method at present, and the prepared HAP is usually in an amorphous structure, is uncontrollable in appearance and is not beneficial to application in gas-phase catalysis.
Taking the supported nano silver catalyst as an example, in the gas phase reaction of CO catalytic oxidation, gas molecules firstly diffuse from the gas phase to the outer surface of the catalyst carrier (external diffusion), then diffuse from the outer surface of the catalyst to the inner surface (internal diffusion), and then CO and O 2 The molecules are adsorbed and reacted on the Ag active sites. The influence of external diffusion can be eliminated by regulating the space velocity of the reaction, and the influence of internal diffusion mainly depends on the particle size, the micro-pore structure and the like of the catalyst. For solid HAP powder catalysts, the pore structure of HAP is an important factor affecting the diffusion of gas molecules inside it.
In addition, in practical research, it is found that: the interaction force between the surface of Ag and the reactant molecules and the carrier is weak, and the problem of low catalytic activity exists. In addition, the melting point of Ag is very low, and the loaded nano Ag catalyst is easy to agglomerate in the processes of heat treatment and catalytic reaction, so that the particle size is enlarged and the nano Ag catalyst is inactivated. The Ag catalyst has the problem of poor thermal stability, and the preparation of the high-dispersion supported nano Ag catalyst is challenging.
Therefore, how to prepare the supported nano silver catalyst with stable structure and hydroxyapatite as a carrier and good thermal stability and high activity becomes a problem to be solved urgently.
Disclosure of Invention
In view of the above, the present invention discloses a preparation method of a lamellar hydroxyapatite carrier and a supported nano silver catalyst, so as to at least solve the problems of an amorphous structure, uncontrollable morphology and the like of hydroxyapatite prepared by a coprecipitation method and a sol-gel method in the past, and the problems of poor thermal stability, low activity and the like of a supported nano silver catalyst.
The invention provides a preparation method of a flaky hydroxyapatite carrier on one hand, which comprises the following steps:
1) Dissolving soluble calcium salt, hydrogen phosphate, a complexing agent and a homogeneous phase precipitator in a solvent, uniformly stirring, and carrying out hydrothermal reaction for 6-24 hours in a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining at the temperature of 100-180 ℃ to obtain a precipitate;
2) Washing, centrifuging and drying the precipitate to obtain HAP with a lamellar structure;
wherein the complexing agent is citric acid.
Preferably, the molar ratio of the complexing agent to the soluble calcium salt is (0.5-3): 1.
Further preferably, the molar ratio of the complexing agent to the soluble calcium salt is 2.
Further preferably, the soluble calcium salt is calcium nitrate or calcium chloride.
More preferably, the hydrogen phosphate is diammonium hydrogen phosphate or disodium hydrogen phosphate.
Further preferably, the homogeneous precipitant is sodium hydroxide and urea.
Further preferably, the solvent is one or a mixture of two of water, ethanol, ethylene glycol and DMF.
Further preferably, the washing in step 2) is specifically: and washing the precipitate with deionized water and anhydrous alcohol for 3-6 times until the precipitate is neutral.
Further preferably, the drying in step 2) is specifically: and (3) placing the centrifuged precipitate in an oven, and drying at the temperature of 40-80 ℃.
The invention also provides a preparation method of the supported nano-silver catalyst, which comprises the following steps:
1) Preparing a flaky hydroxyapatite carrier by any one of the above methods;
2) Placing the flaky hydroxyapatite carrier prepared in the step 1) in a metal silver salt solution with the Ag content of 3% (wt), and performing vacuum drying to obtain a flaky supported nano silver catalyst;
3) Reducing the flaky supported nano silver catalyst in the step 2) in a hydrogen atmosphere to obtain a finished product.
In the preparation method of the flaky hydroxyapatite carrier, the flaky Hydroxyapatite (HAP) carrier is prepared in one step by an in-situ growth method by utilizing a hydrothermal reaction, and citric acid and Ca in a solution 2+ The chelating action of (2) and (3) urea decomposition increases the pH value with the increase of temperature, the stability of Ca and citric acid complex is enhanced, and HAP nano-structure units are easy to grow along the c axis or the a axis. Therefore, the size and the thickness of the HAP lamella can be accurately regulated and controlled by adding the citric acid and matching with proper reaction temperature, and the hydroxyapatite carrier with stable structure can be prepared.
According to the preparation method of the supported nano-silver catalyst, hydroxyapatite with a two-dimensional sheet structure is used as a carrier, the supported nano-silver catalyst is prepared by an impregnation method, the dispersion degree and the thermal stability of active component Ag nano-particles are obviously improved by means of the 'domain limiting effect' of the hydroxyapatite carrier and the 'protection effect' of hydroxyl groups on the surface of the carrier on the silver (Ag) nano-particles, and the 'anchoring' effect of defect sites on the hydroxyapatite carrier on the active component Ag is enhanced by performing hydrogen reduction treatment on the supported nano-silver catalyst, so that the catalytic reaction performance is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present invention, the drawings used in the description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without creative efforts.
FIG. 1 is an X-ray powder diffraction (XRD) pattern of HAP samples prepared according to examples 1, 2, 3, 4 of the present invention;
FIG. 2 is a thermogravimetric plot (TG-DSC) of a HAP sample prepared in example 1 of the present invention;
FIG. 3 is (a) a Scanning Electron Micrograph (SEM) and (b) a Transmission Electron Micrograph (TEM) of a HAP sample prepared in example 1 of the present invention;
FIG. 4 is (a) a Scanning Electron Micrograph (SEM) and (b) a Transmission Electron Micrograph (TEM) of a HAP sample prepared in example 2 of the present invention;
FIG. 5 is a Scanning Electron Micrograph (SEM) of a HAP sample prepared in example 3 of the present invention;
FIG. 6 is a Scanning Electron Micrograph (SEM) of a HAP sample prepared in example 4 of the present invention;
FIG. 7 is a Scanning Electron Micrograph (SEM) of a HAP sample prepared in example 5 of the present invention;
FIG. 8 is a Scanning Electron Micrograph (SEM) of a HAP sample prepared in example 6 of the present invention;
FIG. 9 is a graph showing CO oxidation reaction performance of Ag/HAP samples prepared in examples 7,8 and 9 of the present invention;
FIG. 10 is a graph showing the CO oxidation stability performance of Ag-1 samples according to example 10 of the present invention;
FIG. 11 is a distribution diagram of Ag and Ca elements in selected areas of (a) a Transmission Electron Micrograph (TEM) before use, (b) a high-angle annular dark-field scanning transmission electron micrograph (HAADF-STEM) after use, and (c) a Ag-1 sample prepared in example 7 of the present invention.
Detailed Description
The invention is further illustrated by the following specific embodiments, which are not intended to limit the scope of the invention.
In the prior art, the hydroxyapatite carrier prepared by a coprecipitation method and a sol-gel method is generally in an amorphous structure, the morphology of the hydroxyapatite carrier is uncontrollable, the hydroxyapatite carrier is not beneficial to being applied in gas phase catalysis, and in order to prepare the hydroxyapatite carrier with a fixed structure and morphology, the embodiment provides the following method, which comprises the following specific steps:
1) Dissolving soluble calcium salt, hydrogen phosphate, a complexing agent and a homogeneous phase precipitator in a solvent, uniformly stirring, and carrying out hydrothermal reaction for 6-24 hours in a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining at the temperature of 100-180 ℃ to obtain a precipitate;
2) Washing, centrifuging and drying the precipitate to obtain HAP with a lamellar structure;
wherein the complexing agent in the step 1) is citric acid.
The above embodiment provides a method, wherein a hydrothermal reaction is used to prepare a sheet-shaped Hydroxyapatite (HAP) carrier in one step by an in-situ growth method, and citric acid is added to the carrier and the Ca in the solution is mixed with the citric acid at a temperature of 100-180 DEG C 2+ The chelating effect of the HAP can realize the precise regulation and control of the size and the thickness of the HAP lamella.
Wherein, the mol ratio of the complexing agent to the soluble calcium salt in the above embodiment is (0.5-3) to 1, preferably, the mol ratio of the complexing agent to the soluble calcium salt is 2; the soluble calcium salt can be calcium nitrate or calcium chloride; the hydrogen phosphate can be diammonium hydrogen phosphate or disodium hydrogen phosphate; the homogeneous phase precipitator can be sodium hydroxide and urea; the solvent is one or two of water, ethanol, ethylene glycol and DMF.
The washing mode of the precipitate in the step 2) can be selected from various modes, and the following modes are preferably adopted: washing the precipitate with deionized water and anhydrous alcohol for 3-6 times to neutrality; the drying mode of the precipitate in the step 2) can be selected from various modes, and the following modes are preferably adopted: and (3) placing the centrifuged precipitate in an oven, and drying at the temperature of 40-80 ℃.
The flaky hydroxyapatite carrier prepared by the method is of a two-dimensional lamellar structure, has an open outer surface, two-dimensional anisotropy and thickness from nanometer to sub-nanometer scale, is favorable for diffusion and contact between reactants and active components, and is a catalyst carrier with a better structure.
The preparation method of the flaky hydroxyapatite carrier provided by the embodiment has the following advantages:
1) The HAP nanosheet is synthesized by a simple hydrothermal method, and the method has the advantages of simple process, high product purity, novel structure, strong universality, easiness in amplification and the like.
2) Through research on the HAP preparation process, the HAP nanosheets with different sizes and thicknesses can be synthesized by controlling the citric acid dosage and the hydrothermal temperature, and the prepared Ag/HAP nanosheet catalyst is applied to the catalytic oxidation reaction of CO and shows an obvious carrier size effect.
The surface of Ag has weak interaction force with reactant molecules and carriers, so that the problem of low catalytic activity exists. In addition, the melting point of Ag is very low, and the loaded nano Ag catalyst is easy to agglomerate in the processes of heat treatment and catalytic reaction, so that the particle size is enlarged and the nano Ag catalyst is inactivated. The Ag catalyst has a problem of poor thermal stability, and therefore, the embodiment provides a preparation method of a supported nano silver catalyst to prepare a supported nano silver catalyst with good thermal stability and high activity, and the preparation method specifically comprises the following steps:
1) Preparing a sheet-shaped hydroxyapatite carrier by adopting the method provided by the embodiment;
2) Placing the flaky hydroxyapatite carrier prepared in the step 1) in a metal silver salt solution with the Ag component content of 3% (wt), and carrying out vacuum drying to obtain a flaky supported nano silver catalyst;
3) Reducing the flaky supported nano silver catalyst in the step 2) in a hydrogen atmosphere to obtain a finished product.
Wherein the temperature of vacuum drying in the step 2) is 30 ℃, and the temperature of the flaky supported nano silver catalyst in the step 3) is 300 ℃ and is reduced for 2 hours in a hydrogen atmosphere.
In the embodiment, the supported nano silver catalyst with novel structure and stable performance is synthesized by adopting the flaky hydroxyapatite as the carrier through an impregnation method, and the dispersion degree and the thermal stability of Ag nano particles in the catalyst are improved.
The present invention is further illustrated by the following specific examples, which are not intended to limit the scope of the invention.
Example 1
Dissolving 1.6130g of sodium hydroxide and 4.2028g of citric acid in 20mL of water at room temperature, and putting the solution on a magnetic stirrer to completely dissolve the solution; (2) 2.365g of calcium nitrate is dissolved in 20mL of water, placed on a magnetic stirrer and poured into the mixture in the step (1) after being dissolved; (3) 0.7923g of diammonium hydrogen phosphate is dissolved in 28mL of water, poured into the mixed solution of (1) and (2), 3.0300g of urea is added into a water bath at 30 ℃, stirred for 30min, then the solution is moved into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, hydrothermal is carried out for 12h at 160 ℃, then the temperature is reduced to room temperature, white precipitate is centrifugally separated, washed for three times by water, washed for one time by alcohol until the solution is neutral, and dried in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in figure 1, the synthesized HAP nanosheets all have relatively obvious HAP characteristic peaks (No. 09-0432), and as can be seen from the TG-DSC synchronous thermal analysis result in figure 2, the weight loss is only 3% under the test condition of 800 ℃, no obvious heat release signal exists, which indicates that the synthesized HAP nanosheets have relatively good thermal stability, and as can be seen from SEM and TEM images in figure 3, the HAP nanosheets are uniform in size, rough in surface, 40-60nm in thickness and 2-4 μm in length.
Example 2
At room temperature, (1) 1.6130g of sodium hydroxide and 4.2028g of citric acid are dissolved in 20mL of water and placed on a magnetic stirrer to be completely dissolved; (2) 2.365g of calcium nitrate is dissolved in 20mL of water, placed on a magnetic stirrer and poured into the mixture in the step (1) after being dissolved; (3) 0.7923g of diammonium hydrogen phosphate is dissolved in 28mL of water, poured into the mixed solution of (1) and (2), 3.0300g of urea is added into a water bath at 30 ℃, stirred for 30min, then the solution is moved into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, hydrothermal is carried out for 12h at 180 ℃, then the temperature is reduced to room temperature, white precipitate is centrifugally separated, washed for three times by water, washed by alcohol once to be neutral, and dried in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in FIG. 4, the synthesized HAP nanoplatelets are irregular in size, increased in size, and 70-100nm in thickness.
Example 3
Dissolving 2.4198g of sodium hydroxide and 6.3042g of citric acid in 20mL of water at room temperature, and putting the solution on a magnetic stirrer to completely dissolve the solution; (2) 2.365g of calcium nitrate is dissolved in 20mL of water, placed on a magnetic stirrer and poured into the mixture in the step (1) after being dissolved; (3) 0.7923g of diammonium hydrogen phosphate is dissolved in 28mL of water, poured into the mixed solution of (1) and (2), 3.0300g of urea is added into a water bath at 30 ℃, stirred for 30min, then the solution is moved into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, hydrothermal is carried out for 12h at 180 ℃, then the temperature is reduced to room temperature, white precipitate is centrifugally separated, washed for three times by water, washed by alcohol once to be neutral, and dried in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in FIG. 5, the synthesized HAP nano-sheet has large size and thickness of 100-150nm.
Example 4
At room temperature, (1) dissolving 0.9974g of calcium chloride in 62mL of a mixed solution of water and DMF (1), placing on a magnetic stirrer, and stirring for 10min; (2) adding 1.9611g of disodium hydrogen phosphate into the mixture obtained in the step (1) and stirring the mixture; (3) Adding 420 mu L of sodium hydroxide solution (1 mol/L) into a water bath at 40 ℃, stirring for 30min, then transferring the solution into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal treatment at 120 ℃ for 24h, then cooling to room temperature, centrifugally separating a white precipitate, washing with water for three times, washing with alcohol once to neutrality, and drying in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in FIG. 6, the synthesized HAP nanoplatelets have non-uniform size distribution with sizes ranging from 200 to 300nm.
Example 5
Dissolving 0.4033g of sodium hydroxide and 1.0507g of citric acid in 20mL of water at room temperature, and placing the solution on a magnetic stirrer to completely dissolve the solution; (2) 2.365g of calcium nitrate is dissolved in 20mL of water, placed on a magnetic stirrer and poured into the mixture in the step (1) after being dissolved; (3) 0.7923g of diammonium hydrogen phosphate is dissolved in 28mL of water, poured into the mixed solution of (1) and (2), 3.0300g of urea is added into a water bath at 30 ℃, stirred for 30min, then the solution is moved into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, hydrothermal is carried out for 12h at 180 ℃, then the temperature is reduced to room temperature, white precipitate is centrifugally separated, washed for three times by water, washed by alcohol once to be neutral, and dried in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in FIG. 7, the synthesized HAP nano-sheet has small size and uneven distribution, and the size is 100-300nm.
Example 6
Dissolving 2.4198g of sodium hydroxide and 6.3042g of citric acid in 20mL of water at room temperature, and putting the solution on a magnetic stirrer to completely dissolve the solution; (2) 2.365g of calcium nitrate is dissolved in 20mL of water, placed on a magnetic stirrer and poured into the mixture in the step (1) after being dissolved; (3) 0.7923g of diammonium hydrogen phosphate is dissolved in 28mL of water, poured into the mixed solution of (1) and (2), 3.0300g of urea is added into a water bath at 30 ℃, stirred for 30min, then the solution is moved into a 100mL stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, hydrothermal is carried out for 12h at 180 ℃, then the temperature is reduced to room temperature, white precipitate is centrifugally separated, washed for three times by water, washed by alcohol once to be neutral, and dried in an oven at 50 ℃ to obtain the HAP material with a two-dimensional sheet structure.
As shown in FIG. 8, the synthesized HAP nanoplatelets have large size, thick lamella with thickness of 100-150nm and length of 4-5 μm
Example 7
0.6mg of HAP from example 1 was taken into a beaker and 50. Mu.L of AgNO with a theoretical loading of 3wt.% was pipetted with stirring 3 The solution was added to a beaker, stirred for 20min and dried under vacuum at 30 ℃ for 10h. The catalyst sample is firstly roasted in hydrogen at 300 ℃ for 2h to prepare the Ag/HAP catalyst marked as Ag-1.
Example 8
0.6mg of HAP from example 2 was taken and placed in a beaker, and 50. Mu.L of AgNO with a theoretical loading of 3wt.% was pipetted with stirring 3 The solution was added to a beaker, stirred for 20min and dried under vacuum at 30 ℃ for 10h. The catalyst sample is firstly roasted in hydrogen at 300 ℃ for 2h to prepare the Ag/HAP catalyst marked as Ag-2.
Example 9
0.6mg of HAP from example 4 was taken and placed in a beaker, and 50. Mu.L of AgNO with a theoretical loading of 3wt.% was pipetted with stirring 3 The solution was added to a beaker, stirred for 20min and dried under vacuum at 30 ℃ for 10h. The catalyst sample is firstly roasted in hydrogen at 300 ℃ for 2h to prepare the Ag/HAP catalyst marked as Ag-3.
Example 10
The Ag/HAP catalysts of examples 7,8 and 9 were used in the catalytic oxidation of CO in a fixed bed quartz reactor with a catalyst dosage of 50mg and a feed gas composition of 0.5vol.% CO and 20vol.% O 2 ，N 2 For balancing gas, the mass space velocity is 60000 ml/h.g cat . As can be seen from the catalytic test results of FIG. 9, the Ag-1 and Ag-2 catalysts achieved complete CO conversion at 180 deg.C and 190 deg.C, respectively. The performance is better than that of the Ag-3 sample, obvious carrier size effect is shown, and HAP nano-sheets with uniform size have the best catalytic performance. The stability test of FIG. 10 shows that the Ag-1 catalyst still maintains better activity and stable catalytic performance after reacting for 75 hours at 140 ℃. The TEM results of FIG. 11 show that the Ag-1 catalyst samples have unchanged size of Ag nanoparticles before and after use, are uniformly dispersed, and have a particle size of about 3nm.
The embodiment shows that the HAP nanosheet carrier with the novel structure has obvious 'confinement effect' and 'protection effect' on the active component Ag, so that the small-size nano Ag particles are stable and immobilized, the structure and the performance are stable, and the HAP nanosheet carrier has wide application prospects in the field of precious metal catalysis.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.
Claims (8)
1. A preparation method of a flaky hydroxyapatite carrier of a supported nano-silver catalyst in a CO catalytic oxidation reaction is characterized by comprising the following steps:
1) Dissolving soluble calcium salt, hydrogen phosphate, a complexing agent and a homogeneous phase precipitator in a solvent, uniformly stirring, and carrying out hydrothermal reaction for 6-24 h in a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining at the temperature of 100-180 ℃ to obtain a precipitate;
2) Washing, centrifuging and drying the precipitate to obtain a flaky hydroxyapatite carrier with a lamellar structure;
the complexing agent is citric acid;
the molar ratio of the complexing agent to the soluble calcium salt is (0.5 to 3) to 1;
the homogeneous precipitant is sodium hydroxide and urea;
wherein, the operation of the step 1) is as follows:
at room temperature, (1) dissolving sodium hydroxide and citric acid in a solvent, and placing the solution on a magnetic stirrer to completely dissolve the solution; (2) Dissolving soluble calcium salt in a solvent, placing on a magnetic stirrer, and pouring into the mixture obtained in the step (1) after dissolving; (3) Dissolving hydrogen phosphate in a solvent, pouring the solution into the mixed solution of the step (1) and the step (2), adding urea into a water bath at 30 ℃, stirring for 30min, transferring the solution into a stainless steel high-pressure reaction kettle with a polytetrafluoroethylene lining, carrying out hydrothermal reaction for 6-24 h at the temperature of 100-180 ℃, and cooling to room temperature to obtain a precipitate.
2. The method of claim 1, wherein the molar ratio of the complexing agent to the soluble calcium salt is 2.
3. The method of claim 1, wherein the soluble calcium salt is calcium nitrate or calcium chloride.
4. The method of claim 1, wherein the hydrogen phosphate salt is diammonium hydrogen phosphate or disodium hydrogen phosphate.
5. The preparation method according to claim 1, wherein the solvent is one or a mixture of two of water, ethanol, ethylene glycol, and N, N-Dimethylformamide (DMF).
6. The preparation method according to claim 1, wherein the washing in step 2) is specifically: and washing the precipitate with deionized water and absolute ethyl alcohol for 3-6 times respectively until the precipitate is neutral.
7. The preparation method according to claim 1, wherein the drying in step 2) is specifically: and (3) placing the centrifuged precipitate in an oven, and drying at the temperature of 40-80 ℃.
8. A preparation method of a supported nano silver catalyst used in CO catalytic oxidation reaction is characterized by comprising the following steps:
1) Preparing a flaky hydroxyapatite carrier by adopting the method of any one of claims 1 to 7;
2) Placing the flaky hydroxyapatite carrier prepared in the step 1) in a metal silver salt solution with the Ag component content of 3 wt%, and performing vacuum drying to obtain a flaky supported nano silver catalyst;
3) Reducing the flaky supported nano silver catalyst in the step 2) in a hydrogen atmosphere to obtain a finished product.
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| CN112607721B (en) * | 2021-02-04 | 2022-09-02 | 福州大学 | Method for preparing hydroxyapatite by using desulfurized gypsum |
| CN114029077B (en) * | 2021-11-30 | 2024-01-19 | 中国石油大学(华东) | Catalyst for preparing hydroxy acid by catalytic oxidation of polyol and method thereof |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005097052A (en) * | 2003-09-25 | 2005-04-14 | Japan Science & Technology Agency | Hydroxyapatite with large surface area and its manufacturing method |
| CN101390524A (en) * | 2008-11-07 | 2009-03-25 | 中国人民武装警察部队医学院 | Argentine-loaded hydroxylapatite and preparation method thereof |
| CN101880034A (en) * | 2010-07-08 | 2010-11-10 | 中国科学院上海硅酸盐研究所 | Preparation method and application of porous hydroxyapatite |
| CN102583287A (en) * | 2012-01-17 | 2012-07-18 | 北京林业大学 | Hydroxyapatite with flower-shaped level nanostructure and preparation method thereof |
| CN103101894A (en) * | 2011-11-09 | 2013-05-15 | 上海纳米技术及应用国家工程研究中心有限公司 | Preparation method of flaky nano-hydroxyapatite |
| CN107333798A (en) * | 2017-06-28 | 2017-11-10 | 华东理工大学 | A kind of preparation method of nano silver-group compound disinfectant |
| CN107899079A (en) * | 2017-11-20 | 2018-04-13 | 华东交通大学 | Nano sheet-shaped hydroxyapatite/synthesized thin film and preparation method with brick mud structure |
| CN108379589A (en) * | 2018-03-14 | 2018-08-10 | 西南科技大学 | A kind of preparation method of hydroxyapatite/graphene oxide composite material |
| CN109205583A (en) * | 2018-11-27 | 2019-01-15 | 山东交通学院 | A kind of large scale argentum-carried hydroxylapatite porous microsphere material and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107902636B (en) * | 2017-12-01 | 2020-03-10 | 华中科技大学 | Selenium-doped hydroxyapatite and preparation method thereof |
-
2020
- 2020-01-08 CN CN202010017130.1A patent/CN111054404B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005097052A (en) * | 2003-09-25 | 2005-04-14 | Japan Science & Technology Agency | Hydroxyapatite with large surface area and its manufacturing method |
| CN101390524A (en) * | 2008-11-07 | 2009-03-25 | 中国人民武装警察部队医学院 | Argentine-loaded hydroxylapatite and preparation method thereof |
| CN101880034A (en) * | 2010-07-08 | 2010-11-10 | 中国科学院上海硅酸盐研究所 | Preparation method and application of porous hydroxyapatite |
| CN103101894A (en) * | 2011-11-09 | 2013-05-15 | 上海纳米技术及应用国家工程研究中心有限公司 | Preparation method of flaky nano-hydroxyapatite |
| CN102583287A (en) * | 2012-01-17 | 2012-07-18 | 北京林业大学 | Hydroxyapatite with flower-shaped level nanostructure and preparation method thereof |
| CN107333798A (en) * | 2017-06-28 | 2017-11-10 | 华东理工大学 | A kind of preparation method of nano silver-group compound disinfectant |
| CN107899079A (en) * | 2017-11-20 | 2018-04-13 | 华东交通大学 | Nano sheet-shaped hydroxyapatite/synthesized thin film and preparation method with brick mud structure |
| CN108379589A (en) * | 2018-03-14 | 2018-08-10 | 西南科技大学 | A kind of preparation method of hydroxyapatite/graphene oxide composite material |
| CN109205583A (en) * | 2018-11-27 | 2019-01-15 | 山东交通学院 | A kind of large scale argentum-carried hydroxylapatite porous microsphere material and preparation method thereof |
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