CN113912069B - Preparation method of nano-silica sol particles for catalysis - Google Patents
Preparation method of nano-silica sol particles for catalysis Download PDFInfo
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- CN113912069B CN113912069B CN202111222939.9A CN202111222939A CN113912069B CN 113912069 B CN113912069 B CN 113912069B CN 202111222939 A CN202111222939 A CN 202111222939A CN 113912069 B CN113912069 B CN 113912069B
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- 239000002245 particle Substances 0.000 title claims abstract description 336
- 238000002360 preparation method Methods 0.000 title claims abstract description 93
- 238000006555 catalytic reaction Methods 0.000 title claims abstract description 76
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 250
- 230000036571 hydration Effects 0.000 claims abstract description 69
- 238000006703 hydration reaction Methods 0.000 claims abstract description 69
- 239000000725 suspension Substances 0.000 claims abstract description 53
- 239000007788 liquid Substances 0.000 claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 40
- 239000004005 microsphere Substances 0.000 claims abstract description 25
- 239000000843 powder Substances 0.000 claims abstract description 21
- 239000000084 colloidal system Substances 0.000 claims abstract description 11
- 230000010100 anticoagulation Effects 0.000 claims abstract description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 128
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 70
- 239000000243 solution Substances 0.000 claims description 56
- 239000003795 chemical substances by application Substances 0.000 claims description 46
- 239000000377 silicon dioxide Substances 0.000 claims description 40
- 238000010438 heat treatment Methods 0.000 claims description 35
- 239000007787 solid Substances 0.000 claims description 35
- 238000006243 chemical reaction Methods 0.000 claims description 34
- 238000003756 stirring Methods 0.000 claims description 34
- 239000011259 mixed solution Substances 0.000 claims description 33
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 24
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 claims description 22
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 20
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 claims description 20
- 239000000314 lubricant Substances 0.000 claims description 20
- 239000000375 suspending agent Substances 0.000 claims description 20
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 18
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 18
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- 238000009835 boiling Methods 0.000 claims description 15
- 239000000126 substance Substances 0.000 claims description 15
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- 229940127219 anticoagulant drug Drugs 0.000 claims description 14
- 230000006698 induction Effects 0.000 claims description 12
- 150000004395 organic heterocyclic compounds Chemical class 0.000 claims description 12
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- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 claims description 10
- 238000010791 quenching Methods 0.000 claims description 10
- 230000000171 quenching effect Effects 0.000 claims description 10
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- MGADZUXDNSDTHW-UHFFFAOYSA-N 2H-pyran Chemical compound C1OC=CC=C1 MGADZUXDNSDTHW-UHFFFAOYSA-N 0.000 claims description 9
- 239000001294 propane Substances 0.000 claims description 9
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 7
- CZPWVGJYEJSRLH-UHFFFAOYSA-N Pyrimidine Chemical compound C1=CN=CN=C1 CZPWVGJYEJSRLH-UHFFFAOYSA-N 0.000 claims description 7
- 238000005507 spraying Methods 0.000 claims description 7
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 6
- 230000007613 environmental effect Effects 0.000 claims description 6
- -1 amine compounds Chemical class 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 150000001335 aliphatic alkanes Chemical class 0.000 claims description 3
- 150000002148 esters Chemical class 0.000 claims description 3
- 229920000642 polymer Polymers 0.000 claims description 3
- 239000003054 catalyst Substances 0.000 abstract description 76
- 230000008569 process Effects 0.000 abstract description 17
- 238000005516 engineering process Methods 0.000 abstract description 14
- 238000007710 freezing Methods 0.000 abstract description 14
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- 239000003463 adsorbent Substances 0.000 abstract description 12
- 239000000853 adhesive Substances 0.000 abstract description 10
- 230000001070 adhesive effect Effects 0.000 abstract description 10
- 238000000859 sublimation Methods 0.000 abstract description 9
- 230000008022 sublimation Effects 0.000 abstract description 9
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 238000004108 freeze drying Methods 0.000 abstract description 6
- 239000007921 spray Substances 0.000 abstract description 5
- 239000000047 product Substances 0.000 description 67
- 235000012239 silicon dioxide Nutrition 0.000 description 28
- 239000007789 gas Substances 0.000 description 17
- 230000002776 aggregation Effects 0.000 description 13
- 230000000694 effects Effects 0.000 description 13
- 239000005543 nano-size silicon particle Substances 0.000 description 13
- 238000001179 sorption measurement Methods 0.000 description 13
- 238000012360 testing method Methods 0.000 description 13
- 238000005054 agglomeration Methods 0.000 description 11
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 10
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 10
- 230000001699 photocatalysis Effects 0.000 description 9
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- 239000000741 silica gel Substances 0.000 description 8
- 229910002027 silica gel Inorganic materials 0.000 description 8
- 230000003647 oxidation Effects 0.000 description 7
- 230000003197 catalytic effect Effects 0.000 description 6
- 230000008859 change Effects 0.000 description 6
- 230000007547 defect Effects 0.000 description 6
- 239000010865 sewage Substances 0.000 description 6
- 230000015556 catabolic process Effects 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 238000006731 degradation reaction Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 5
- 238000011068 loading method Methods 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 229910021645 metal ion Inorganic materials 0.000 description 5
- 239000002105 nanoparticle Substances 0.000 description 5
- 229910002651 NO3 Inorganic materials 0.000 description 4
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 150000002391 heterocyclic compounds Chemical class 0.000 description 4
- 238000001027 hydrothermal synthesis Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000004064 recycling Methods 0.000 description 4
- 239000004408 titanium dioxide Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 230000008901 benefit Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 150000004677 hydrates Chemical class 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 239000005416 organic matter Substances 0.000 description 3
- 238000010298 pulverizing process Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 2
- ATHHXGZTWNVVOU-UHFFFAOYSA-N N-methylformamide Chemical compound CNC=O ATHHXGZTWNVVOU-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 230000001112 coagulating effect Effects 0.000 description 2
- 230000015271 coagulation Effects 0.000 description 2
- 238000005345 coagulation Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000000635 electron micrograph Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 2
- 150000002736 metal compounds Chemical class 0.000 description 2
- 239000011941 photocatalyst Substances 0.000 description 2
- FGIUAXJPYTZDNR-UHFFFAOYSA-N potassium nitrate Chemical compound [K+].[O-][N+]([O-])=O FGIUAXJPYTZDNR-UHFFFAOYSA-N 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 description 1
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- 229920002845 Poly(methacrylic acid) Polymers 0.000 description 1
- 229920002873 Polyethylenimine Polymers 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- JVVXZOOGOGPDRZ-SLFFLAALSA-N [(1R,4aS,10aR)-1,4a-dimethyl-7-propan-2-yl-2,3,4,9,10,10a-hexahydrophenanthren-1-yl]methanamine Chemical compound NC[C@]1(C)CCC[C@]2(C)C3=CC=C(C(C)C)C=C3CC[C@H]21 JVVXZOOGOGPDRZ-SLFFLAALSA-N 0.000 description 1
- UGACIEPFGXRWCH-UHFFFAOYSA-N [Si].[Ti] Chemical compound [Si].[Ti] UGACIEPFGXRWCH-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- APUPEJJSWDHEBO-UHFFFAOYSA-P ammonium molybdate Chemical compound [NH4+].[NH4+].[O-][Mo]([O-])(=O)=O APUPEJJSWDHEBO-UHFFFAOYSA-P 0.000 description 1
- 229940010552 ammonium molybdate Drugs 0.000 description 1
- 235000018660 ammonium molybdate Nutrition 0.000 description 1
- 239000011609 ammonium molybdate Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 1
- 229920001400 block copolymer Polymers 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000004523 catalytic cracking Methods 0.000 description 1
- 239000008395 clarifying agent Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 1
- 229910001981 cobalt nitrate Inorganic materials 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000008394 flocculating agent Substances 0.000 description 1
- 239000007863 gel particle Substances 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 230000000887 hydrating effect Effects 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- RXPAJWPEYBDXOG-UHFFFAOYSA-N hydron;methyl 4-methoxypyridine-2-carboxylate;chloride Chemical compound Cl.COC(=O)C1=CC(OC)=CC=N1 RXPAJWPEYBDXOG-UHFFFAOYSA-N 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000010985 leather Substances 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- QNILTEGFHQSKFF-UHFFFAOYSA-N n-propan-2-ylprop-2-enamide Chemical compound CC(C)NC(=O)C=C QNILTEGFHQSKFF-UHFFFAOYSA-N 0.000 description 1
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000036314 physical performance Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 235000010333 potassium nitrate Nutrition 0.000 description 1
- 239000004323 potassium nitrate Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000000275 quality assurance Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000011863 silicon-based powder Substances 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- BGQMOFGZRJUORO-UHFFFAOYSA-M tetrapropylammonium bromide Chemical compound [Br-].CCC[N+](CCC)(CCC)CCC BGQMOFGZRJUORO-UHFFFAOYSA-M 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Images
Classifications
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/141—Preparation of hydrosols or aqueous dispersions
- C01B33/1415—Preparation of hydrosols or aqueous dispersions by suspending finely divided silica in water
-
- 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
- B01J21/08—Silica
-
- B01J35/23—
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- B01J35/653—
-
- B01J35/657—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/64—Nanometer sized, i.e. from 1-100 nanometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
Abstract
A preparation method of nano-silica sol particles for catalysis comprises the steps of preparation of high-purity silica sol hydration liquid, preparation of anticoagulation high-purity silica sol hydration liquid, preparation of nano-silica sol particle mixed liquid, preparation of nano-silica sol particle suspension, preparation of nano-silica sol frozen particles, preparation of nano-silica sol particles and the like. The invention obtains colloid or powder products composed of hollow nano microspheres with ultrahigh specific surface area, uniform appearance and rough surface with needle-shaped protrusions or concave-convex points on the surface by rehydrating high-purity silica sol, special anticoagulation treatment and creatively applying suspension treatment technology, spray freezing technology and freeze-drying sublimation technology, and provides quality guarantee for the application of the hollow nano microspheres as an adsorbent, a catalyst or a catalyst carrier and a catalyst adhesive; the invention has stable process, no pollution to the environment in the production process and excellent product performance, thereby having great popularization and application values.
Description
Technical Field
The invention relates to a preparation method of silica sol particles, in particular to a preparation method of nano silica sol particles for catalysis, belonging to the technical field of production and preparation of silica sol particle materials.
Background
Silica sol or silica sol for short is a dispersion of nano-scale silica particles in water or a solvent, and can also become a solid after partial free moisture is removed; due to SiO in the silica sol 2 Contains a large amount of water and hydroxyl groups, so that the molecular formula of the silica sol can be expressed as SiO 2 ·nH 2 O。
The silica sol has wide application, can be used as an adsorbent, a surface catalyst, a catalyst carrier, a textile dye auxiliary agent, a leather modification treatment agent, a coating modifier of pigment, a clarifying agent and a flocculating agent of sewage and wine, is also an effective retention and drainage aid in the paper making industry and a baking binding agent of refractory materials, and can also be used as an adhesive in the food industry, an adhesive in the electronic industry, a nano polishing agent and the like.
By searching, a plurality of preparation methods of silica sol with special application can be obtained, such as:
the invention patent application of a preparation method and application of photocatalytic gel particles (application number: 202010281792. X), the invention patent of uniform silica microspheres and a preparation method and application thereof (application number: 201710045581.4) and the like prepares silica sol or silica microspheres with corresponding application by taking acid silica sol as a starting raw material;
the invention patent of silica sol with controllable particle form and a preparation method thereof (application number: 202010264209.4) changes alkaline silica sol into acidic silica sol, thereby changing the morphology of the silica sol and obtaining spherical or non-spherical silica sol to meet related requirements;
the invention patent application of metal modified silica sol for synthesizing SAPO-34 molecular sieve and a preparation method thereof (application number: 202010134980. X) obtains the metal modified silica sol for specific application by mixing, precipitating and filtering the silica sol and a metal salt solution;
in addition, patent of invention TiO 2 Preparation method and application of silica sol (application number: 201710167999.2), invention patent of a method for obtaining titanium-silicon powder for denitration catalyst by using silica sol as seed crystal and hydrolyzing (application number: 201510510755.0), invention patent of a silica sol and silica-alumina sol and preparation method and application thereof, catalytic cracking catalyst and preparation method thereof, and the like, wherein solid powder containing silicon dioxide is obtained by doping titanium dioxide, aluminum oxide and the like, so that related application is met;
in addition, the invention patent of "preparation method of silica gel for polyolefin catalyst carrier" (application No. 201510527284.4), the invention patent of "preparation method of silica gel carrier for catalyst loading" (application No. 201711211509.0) and the like provides a preparation method of silica gel for catalyst loading;
meanwhile, the invention patent application of nano-silica microspheres with surface topological structures and a preparation method thereof (application number: 201910508292.2) provides a preparation method of nano-silica microspheres with surface topological structures.
However, practice shows that the modified silica sol or modified silica solid powder prepared by the prior art has the problems of mutual adhesion of particles, non-uniform surface morphology, low bonding strength with a catalyst or poor catalyst compatibility, complex production process and the like.
Furthermore, there are a number of technical and technical literature, such as:
and (3) DOI:10.13416/j.ca.2016.11.014, DOI:10.16552/j.cnki.issn1001-1625.2016.02.015, DOI:10.16552/j.cnki.issn1001-1625.2016.02.015, DOI: the modified silica sol or modified silica solid powder prepared by the method for preparing silica sol related to special application provided by 10.16490/j. Cnki. Issn.1001-3660.2006.01.021 and the like also has the problems of poor particle dispersibility of the silica sol, the modified silica sol or the modified silica solid powder, namely, the so-called agglomeration phenomenon, non-uniform surface morphology of the obtained product particles, low bonding strength with the catalyst, low catalyst activity loading amount, complex preparation process and the like, and meanwhile, the technical documents do not provide or only partially provide methods, measures and processes for solving the technical problems, and do not solve the technical problems.
However, the silica sol, modified silica sol or silica particle powder obtained by the prior art generally has the defects of too high content of metal ions, insufficient specific surface area, poor applicability and universality and the like, so how to obtain silica sol, modified silica sol or silica particle powder which has good broad spectrum and large specific surface area and is suitable for catalytic application is a goal pursued by relevant product manufacturers and researchers.
To obtain a larger specific surface area, it is an effective method to change the morphology of silica particles, and for this reason, there is a method in the prior art to assemble and grow silica by directional deposition through silica sol particle templates, so as to obtain silica particles with different surface morphologies, for example, patent documents:
CN202010192368.8, CN201910495867.1, CN201810914163.9, CN201810914164.3, CN201711392437.4, CN201611141631.0, CN201610130057.2, CN201710423647.9, CN201310503563.8, CN201210253807.7, CN201010276413.4, CN 200095106354.1, CN1346790A, etc., respectively, polyethylene glycol, polyethylene imine, hexadecyl trimethyl ammonium bromide, dehydroabietylamine, TPABr, polyethylene glycol polymethacrylic acid N, N dimethylaminoethyl ester poly N isopropyl acrylamide block copolymer, glucose, tetrapropyl ammonium bromide, sucrose, methyl formamide, etc. are taken as templates, and a sol-gel process is utilized to deposit and assemble silica sol particles between interfaces of the organic template, so as to prepare the porous silica powder material and obtain a large specific surface area.
However, the existing porous silica particle assembling template generally has the defects of large molecular weight distribution difference, unstable physical and chemical structure of the template, easy mutual adhesion between the templates, large influence and change of the template due to temperature and the like, thereby influencing the assembling quality of the porous silica particles and failing to achieve the expected use effect.
Disclosure of Invention
In order to overcome the defects of the prior art, the embodiment of the invention provides a preparation method of nano silica sol particles for catalysis, which aims to:
the method provided by the invention can prepare and produce a colloid or particle powder product of the hollow silicon dioxide nano microsphere particles which have high dispersity, wide adaptability, rough surface appearance with needle-shaped bulges or concave-convex points on the particles and ultrahigh specific surface area, improve the specific surface area, be used as an adsorbent, a catalyst or a catalyst carrier, a catalyst adhesive and the like, meet the production requirements, simplify the production flow, improve the product quality, and obtain corresponding economic benefits while obtaining better social benefits.
In order to achieve the purpose, the invention provides the following technical scheme:
a method for preparing nano-silica sol particles for catalysis comprises the following steps:
the preparation method comprises the steps of preparing a high-purity silica sol hydration solution, preparing an anticoagulant high-purity silica sol hydration solution, preparing a mixed solution of nano-silica sol particles, preparing a suspension of the nano-silica sol particles, preparing frozen nano-silica sol particles and preparing the nano-silica sol particles, wherein the steps of:
the preparation method of the high-purity silica sol hydration solution comprises the following steps:
adding a high-purity silica sol solution into a high-pressure reaction device, then adding pure water with the mass of 25-55% of that of the high-purity silica sol solution, stirring and heating to above the boiling point of water to enable silica sol particles of the high-purity silica sol to be rehydrated, refined and dissolved to obtain the high-purity silica sol hydrated solution;
the preparation method of the anticoagulant high-purity silica sol hydration liquid comprises the following steps:
under a high pressure state, adding an isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds and a lubricant consisting of micromolecular volatile organic compounds or polyethylene glycol into the high-purity silica sol hydration liquid, and uniformly stirring to prevent silica sol particles in the high-purity silica sol hydration liquid from adhering and store smooth particles of the silica sol particles to obtain the anticoagulant high-purity silica sol hydration liquid;
the preparation method of the mixed solution of the nano-silica sol particles comprises the following steps:
adding a forming template agent consisting of a six-membered organic heterocyclic compound into the anticoagulated high-purity silica sol hydration liquid at a temperature above the boiling point of water and under a high pressure and in a stirring state, so that silica sol particles in the anticoagulated high-purity silica sol hydration liquid are directionally deposited, assembled and grown on the interface of the six-membered organic heterocyclic compound under the induction of the forming template agent to obtain nano silica sol particle mixed liquid;
the preparation method of the nano-silica sol particle suspension specifically comprises the following steps:
reducing the temperature of the mixed solution of the nano-silica sol particles to a temperature range below the boiling point of water and above room temperature, simultaneously reducing the environmental pressure of the mixed solution of the nano-silica sol particles, then adding a suspending agent consisting of organic volatile substances, and stirring to prepare a suspension of the nano-silica sol particles;
the preparation method of the nano-silica sol frozen particles specifically comprises the following steps:
cooling the nano-silica sol particle suspension to room temperature, and then spraying the nano-silica sol particle suspension into a quenching chamber to rapidly freeze the nano-silica sol particle suspension to obtain nano-silica sol frozen particles;
the preparation steps of the nano silica sol particles specifically comprise:
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 70%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the nano-silica sol frozen particles to normal pressure to obtain a product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano microspheres with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, and the product is colloid with the water content less than or equal to 70%; or
And carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 30%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the nano-silica sol frozen particles to normal pressure to obtain the product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano-microspheres with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area, and the product is particle powder with the water content less than or equal to 30%.
Further:
the high-purity silica sol has the mass percentage concentration of 20-50% of silica, the purity of more than 99.999% of silica and the average particle size of silica sol particles of 2-40 nm.
Further:
the isolating agent is composed of low molecular amine compounds, the lubricant is composed of lower alcohol or low molecular alkane, and the suspending agent is selected from low molecular and low viscosity alcohol or ester polymers.
Further:
the release agent is any one of ammonia gas and methylamine or a mixture of the ammonia gas and the methylamine, the lubricant is a mixture composed of any two of methanol, methane or propane, the suspending agent is any one of polyethylene glycol and vinyl acetate, and the molding template is a mixture composed of any two of pyridine, pyrimidine and pyran.
And further:
the separant is ammonia with the solid content of 1-2% and/or methylamine with the solid content of 0.5-1% of the high-purity silica sol;
the lubricant is a mixture of any two of methanol which is 10 times of the volume of the high-purity silica sol, methane which is 5 times of the volume of the high-purity silica sol, or propane which is 3 times of the volume of the high-purity silica sol;
the suspending agent is polyethylene glycol accounting for 0.5 to 1 percent of the mass of the high-purity silica sol or vinyl acetate accounting for 0.1 to 0.4 percent of the mass of the high-purity silica sol;
the forming template is a mixture consisting of any two of pyridine with the solid content of 0.1-0.6%, pyrimidine with the solid content of 0.2-0.45% or pyran with the solid content of 0.1-0.2%.
And further:
in the preparation step of the high-purity silica sol hydration solution, the heating temperature is 110-120 ℃, and the stirring speed is 200-1000 r/min.
Further:
in the step of preparing the mixed solution of the nano-silica sol particles, the temperature above the boiling point of water means that the temperature of the anticoagulated high-purity silica sol hydration solution is maintained at 120-180 ℃, the high pressure means that the anticoagulated high-purity silica sol hydration solution is in a pressure environment of 2-8 MPa, and the silica sol particles are directionally deposited and assembled on the interface of the hexahydric organic heterocyclic compound under the induction of the molding template agent and grow for 0.1-1 hour.
And further:
in the step of preparing the nano-silica sol particle suspension, the temperature interval between the boiling point and the room temperature is that the temperature of the nano-silica sol particle mixed solution is reduced to 60 to 80 ℃, and the environmental pressure of the nano-silica sol particle mixed solution is reduced to 0.1 to 0.5MPa.
And further:
in the preparation step of the nano-silica sol frozen particles, the quenching chamber is an operation space cooled by liquid nitrogen, and the temperature of the nano-silica sol frozen particles is below-60 ℃.
And further:
in the preparation step of the nano-silica sol particles, the temperature rise rate of the rapid temperature rise is 80-120 ℃/hour.
Compared with the prior art, the invention has the beneficial effects and remarkable progresses that:
1) The preparation method of the nano-silica sol particles for catalysis provided by the invention can prepare a product of hollow nano-microsphere particles of silica with high dispersity, wide adaptability, rough surface appearance of the particles with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area through the steps of preparing high-purity silica sol hydration liquid, preparing anticoagulant high-purity silica sol hydration liquid, preparing mixed liquid of nano-silica sol particles, preparing suspension of the nano-silica sol particles, preparing frozen particles of the nano-silica sol, preparing dehydrated nano-silica sol particles and preparing nano-silica sol particles, and can be used as an adsorbent, a catalyst or a catalyst carrier, a catalyst adhesive and the like for relevant application;
2) The nano-silica sol particles for catalysis prepared by the preparation method of nano-silica sol particles for catalysis provided by the invention adopt high-purity silica sol as a starting material, and are rehydrated, refined and dissolved, and metal or metal compound and other substances containing metal ions are not added in the whole preparation process of the nano-silica sol particles for catalysis, so that the possibility brought by the metal ions is removed from the source, the obtained product has higher purity, is more suitable for being used as a catalyst or a catalyst carrier, and has better applicability and universality;
3) In the process of preparing the nano-silica sol particles for catalysis by adopting the preparation method of the nano-silica sol particles for catalysis, the hexatomic organic heterocyclic compound is adopted as the forming template agent, so that the silica sol particles in the high-purity silica sol hydration solution have better space induction interface and growth interface in the forming process of the silica particles, and rough surface hollow nano-microspheres with uniform surface appearance and good surface acicular protrusions or concave-convex points can be formed, and products with larger specific surface area, higher bonding strength with a catalyst, larger catalyst activity loading capacity, better adsorption capacity and the like which can be used as an adsorbent, a catalyst carrier and the like are obtained;
4) In the preparation method of the nano-silica sol particles for catalysis, the hexahydric organic heterocyclic compound which has small molecular weight distribution difference, stable physicochemical properties, difficult mutual adhesion among molecules and small change under the influence of temperature is adopted as the molding template agent, so that the defects of the existing molding template agent are overcome, and the rough surface hollow nano-microspheres which have uniform surface appearance and good surface acicular protrusions or concave-convex points can be obtained, and an unexpected effect is achieved;
5) In addition, in the invention, because the isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds and the lubricant consisting of micromolecular volatile organic compounds or polyethylene glycol are used, the excessive growth of silicon dioxide crystal particles can be effectively avoided, the adhesion of silicon sol coagulation particles is prevented, and the uniform surface appearance of the silicon dioxide crystal particles is ensured in the preparation process of the nano silicon dioxide sol particles for catalysis;
6) In the preparation method of the nano-silica sol particles for catalysis, the separant composed of ammonia gas and/or alkaline volatile organic compounds can form alkaline hydrates with silica sol in a high-purity silica sol hydration solution and water molecules thereof, and has the same electrical property with silica gel aggregates taking a stable hexabasic heterocyclic compound forming template agent as a core, so that the separant and the silica gel aggregates are mutually repelled to play an isolation role in preventing the silica gel aggregates from being bonded and growing, and the separant added is the volatile organic compounds and can be decomposed and escaped from the hydrates under the conditions of reduced pressure and normal temperature, so that the purity of a final product cannot be influenced;
7) In the invention, the lubricant consisting of micromolecule volatile organic compounds or polyethylene glycol can form hydrate with water and silica sol under the high-pressure hydrothermal condition, the hydrate has good lubricity and can effectively prevent the silica sol from coagulating, so that the uniformly dispersed silica nanoparticle suspension can be ensured to be obtained, and the high-quality product which is high in dispersity, difficult to coagulate and easy to store can be obtained through the subsequent preparation steps;
8) In the preparation method of the nano-silica sol particles for catalysis, the suspending agent solution is added, so that the aggregation and agglomeration of new silica particles and the layered analysis of the mixed solution are prevented, the normal operation of subsequent operation can be ensured, the uniformly distributed nano-silica sol frozen particles are obtained, and the final qualified product is ensured;
9) The invention creatively applies the freeze-drying technology, removes part of water, organic volatile suspending agent and other volatile substances in the nano-silica sol frozen particles from the nano-silica sol frozen particles by freezing and sublimating the silica nano-particle suspension, and forms cavities in the nano-silica sol frozen particles while removing the water and the organic volatile substances, thereby obtaining the hollow nano-microspheres with uniform surface appearance, ultrahigh specific surface area, and rough surface with good surface acicular bulge or concave-convex point growth, and providing quality guarantee for the application of the hollow nano-microspheres as an adsorbent, a catalyst or a catalyst carrier;
10 In conclusion, the invention can assemble and grow at the interface of the hexahydric heterocyclic compound forming template agent with stable physical performance and good space interface by hydrating the high-purity silica sol and carrying out anticoagulation treatment on the high-purity silica sol hydration solution to form the hollow silica particle with unique characteristics and ultra-large specific surface area, and obtains the required product by suspension treatment and creatively applying spray freezing technology and freeze-drying technology, thereby forming a set of complete, novel and unique preparation method.
Drawings
To more clearly illustrate the technical solution of the present invention, the drawings required for the embodiment of the present invention will be briefly described below.
Obviously:
the drawings in the following description are only part of the embodiments of the present invention, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts, but the other drawings also belong to the drawings required to be used by the embodiments of the present invention.
FIG. 1 is a Scanning Electron Microscope (SEM) electron micrograph of nano-silica sol particles for catalysis provided in example 1 of the present invention;
FIG. 2 shows the combination of nano-silica sol particles for catalysis with CO, provided in example 1 of the present invention 2 Isothermal adsorption profile of gas.
Detailed Description
In order to make the objects, technical solutions, advantages and significant progress of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings provided in the embodiments of the present invention, and it is obvious that all of the described embodiments are only some embodiments of the present invention, but not all embodiments;
all other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that:
the terms "first," "second," and the like in the description and claims of the present invention and in the drawings of embodiments of the present invention, are used for distinguishing between different objects and not for describing a particular order;
moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
It is to be understood that:
in the description of the embodiments of the present invention, some basic operation terms commonly used in the art, for example, "heating", "stirring", "mixing", "dissolving", "washing", "filtering", and "drying", etc., are used, and it should be understood that these terms are used in a broad sense, and may be performed by various conventional apparatuses and instruments in the art, or may be performed by the latest apparatuses, such as program control operation, unmanned automatic operation, etc., unless otherwise specifically limited, and those skilled in the art can understand the specific meaning of the above terms in the present invention according to specific situations and use specific operation methods to achieve the operation purpose.
It should also be noted that:
the following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments;
further, the raw materials, equipment and facilities mentioned in the following specific examples are commercially available.
The technical means of the present invention will be described in detail below with specific examples.
Examples
The embodiment provides a preparation method of nano silica sol particles for catalysis, which specifically comprises the following steps:
the preparation method comprises the steps of preparing a high-purity silica sol hydration solution, preparing an anticoagulant high-purity silica sol hydration solution, preparing a mixed solution of nano-silica sol particles, preparing a suspension of the nano-silica sol particles, preparing frozen nano-silica sol particles and preparing the nano-silica sol particles, wherein the steps of:
the preparation method of the high-purity silica sol hydration solution comprises the following steps:
adding high-purity silica sol solution into a high-pressure reaction device, then adding pure water with the mass of 25-55% of that of the high-purity silica sol solution, stirring and heating to be above the boiling point of water so as to enable silica sol particles of the high-purity silica sol to be hydrated, refined and dissolved again, thus obtaining high-purity silica sol hydrated solution;
the preparation method of the anticoagulant high-purity silica sol hydration liquid comprises the following steps:
under a high pressure state, adding an isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds and a lubricant consisting of micromolecular volatile organic compounds or polyethylene glycol into the high-purity silica sol hydration solution, and uniformly stirring to prevent silica sol particles in the high-purity silica sol hydration solution from being adhered and store smooth particles of the silica sol particles to obtain the anticoagulant high-purity silica sol hydration solution;
the preparation method of the mixed solution of the nano-silica sol particles comprises the following steps:
adding a forming template agent consisting of a six-membered organic heterocyclic compound into the anticoagulated high-purity silica sol hydration liquid at a temperature above the boiling point of water and under a high pressure and in a stirring state, so that silica sol particles in the anticoagulated high-purity silica sol hydration liquid are directionally deposited, assembled and grown on the interface of the six-membered organic heterocyclic compound under the induction of the forming template agent to obtain nano silica sol particle mixed liquid;
the preparation method of the nano-silica sol particle suspension specifically comprises the following steps:
reducing the temperature of the mixed solution of the nano-silica sol particles to a temperature range below the boiling point of water and above room temperature, simultaneously reducing the environmental pressure of the mixed solution of the nano-silica sol particles, then adding a suspending agent consisting of organic volatile substances, and stirring to prepare a suspension of the nano-silica sol particles;
the preparation method of the nano-silica sol frozen particles specifically comprises the following steps:
cooling the nano-silica sol particle suspension to room temperature, and then spraying the nano-silica sol particle suspension into a quenching chamber to rapidly freeze the nano-silica sol particle suspension to obtain nano-silica sol frozen particles;
the preparation method of the nano silica sol particles specifically comprises the following steps:
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 70%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the temperature to normal pressure to obtain a product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano microspheres with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area, and the product is colloid with the water content less than or equal to 70%; or
Carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 30%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the temperature to normal pressure to obtain a product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano microspheres with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, and the product is particle powder with the water content less than or equal to 30%.
From the above description, it can be seen that:
the preparation method of the nano-silica sol particles for catalysis provided by the embodiment is to prepare a product of hollow nano-silica microsphere particles with high dispersity, wide adaptability, rough surface morphology of the particles with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area through a preparation step of a high-purity silica sol hydration liquid, a preparation step of an anti-freezing high-purity silica sol hydration liquid, a preparation step of a mixed solution of nano-silica sol particles, a preparation step of a suspension of the nano-silica sol particles, a preparation step of frozen nano-silica sol particles, a preparation step of dehydrated nano-silica sol particles and a preparation step of the nano-silica sol particles, and can be used as an adsorbent, a catalyst or a catalyst carrier and the like for relevant application.
In this embodiment:
the adopted high-purity silica sol is a commercial product with the mass percentage concentration of the silica reaching 20-50%, the purity of the silica being more than 99.999% and the average particle size of silica sol particles being 2-40 nm.
From the above description, it can be seen by those skilled in the art that:
the high-purity silica sol is used as a starting material, so that a basis and guarantee are provided for obtaining a high-purity final product; and metal or metal compound and other substances containing metal ions are not added in the process of rehydrating, refining and dissolving the high-purity silica sol and preparing the whole nano silica sol particles for catalysis, so that the possibility of metal ion introduction is fundamentally removed, the obtained product has higher purity, is more suitable for being used as a catalyst or a catalyst carrier, and has better applicability and universality.
In addition, in the present embodiment:
the isolating agent is composed of low molecular amine compounds, the lubricant is composed of lower alcohol or low molecular alkane, and the suspending agent is selected from low molecular and low viscosity alcohol or ester polymers.
Further, in this embodiment:
the isolating agent is any one of ammonia gas and methylamine or a mixture of ammonia gas and methylamine, the lubricant is a mixture composed of any two of methanol, methane or propane, and the suspending agent is any one of polyethylene glycol and vinyl acetate.
Further, in this embodiment:
the separant is high-purity silica sol with the solid content of 1-2% of ammonia gas and/or 0.5-1% of methylamine;
the lubricant is a mixture of any two of methanol which is 10 times of the volume of the high-purity silica sol, methane which is 5 times of the volume of the high-purity silica sol, or propane which is 3 times of the volume of the high-purity silica sol;
the suspending agent is polyethylene glycol with the mass of 0.5-1% of the high-purity silica sol or vinyl acetate with the mass of 0.1-0.4%.
From the above description, it can be seen by those skilled in the art that:
in the embodiment, the isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds and the lubricant consisting of micromolecular volatile organic compounds or polyethylene glycol are used, so that excessive growth of silicon dioxide crystal particles can be effectively avoided, adhesion of silicon sol coagulation particles is prevented, and the surface appearance uniformity of the silicon dioxide crystal particles is ensured in the preparation process of the nano silicon dioxide sol particles for catalysis;
specifically, the method comprises the following steps:
the isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds can form alkaline hydrate with silica sol and water molecules thereof in high-purity silica sol hydration liquid, has the same electrical property with silica gel aggregates taking the stable hexahydric heterocyclic compound forming template agent as cores, and thus is mutually exclusive, and plays a role in preventing the silica gel aggregates from being bonded and growing, and because the added isolating agent is the volatile organic compounds, the isolating agent can be decomposed and escaped from the hydrates under the conditions of reduced pressure and normal temperature, the purity of the final product cannot be influenced;
the lubricant consisting of the micromolecule volatile organic matter or the polyethylene glycol can form a hydrate with water and silica sol under the high-pressure hydrothermal condition, the hydrate has good lubricity and can effectively prevent the silica sol from coagulating, so that the uniformly dispersed silica nanoparticle suspension can be ensured to be obtained, and a high-quality product which is high in dispersity, difficult to coagulate and easy to store can be obtained through the subsequent preparation steps;
the suspending agent solution is added, so that the aggregation and agglomeration of the new silicon dioxide particles and the layered analysis of the mixed solution are prevented, the normal operation of the subsequent operation can be ensured, the uniformly distributed nano silicon dioxide sol frozen particles are obtained, and the final qualified product is ensured.
Further, in this embodiment:
the molding template is a mixture consisting of any two of pyridine, pyrimidine and pyran.
Further, in this embodiment:
the forming template is a mixture of any two of high-purity silica sol with the solid content of 0.1-0.6% of pyridine, 0.2-0.45% of pyrimidine or 0.1-0.2% of pyran.
From the above description, it can be seen by those skilled in the art that:
the embodiment adopts the hexatomic organic heterocyclic compound which has small molecular weight distribution difference, stable physicochemical property, difficult mutual adhesion among molecules and small influence and change of temperature as the molding template agent, so that the defects and the defects of large molecular weight distribution difference, unstable physical and chemical structure of the templates, easy mutual adhesion among the templates, large influence and change of the temperature of the templates and the like existing in the conventional molding template agent can be overcome, the silica sol particles in the high-purity silica sol hydration liquid have better space induction interface and growth interface in the molding process of the silica sol particles, and rough surface hollow nano microspheres with uniform surface appearance and good surface acicular protrusions or concave-convex points can be formed, so that products which have larger specific surface area, higher bonding strength with the catalyst, larger catalyst activity loading capacity and better adsorption capacity, can be used as an adsorbent, the catalyst, a catalyst carrier, a catalyst adhesive and the like can be obtained, and unexpected effects can be achieved.
In this embodiment:
in the preparation step of the high-purity silica sol hydration solution, the heating temperature is 110-120 ℃, and the stirring speed is 200-1000 r/min;
in the preparation step of the mixed solution of the nano-silica sol particles, the temperature of the mixed solution of the nano-silica sol particles is above the boiling point of water, namely the temperature of the anticoagulated high-purity silica sol hydration solution is kept between 120 and 180 ℃, the high pressure of the mixed solution of the nano-silica sol particles means that the anticoagulated high-purity silica sol hydration solution is in a pressure environment of 2 to 8MPa, and the silica sol particles are directionally deposited and assembled on the interface of the six-membered organic heterocyclic compound under the induction of the forming template agent and grow for 0.1 to 1 hour.
In the preparation step of the nano-silica sol particle suspension, the temperature interval below the boiling point and above the room temperature is that the temperature of the nano-silica sol particle mixed solution is reduced to 60-80 ℃, and the environmental pressure of the nano-silica sol particle mixed solution is reduced to 0.1-0.5 MPa;
in the preparation step of the nano-silica sol frozen particles, a quenching chamber is an operation space cooled by liquid nitrogen, and the temperature of the nano-silica sol frozen particles is below-60 ℃;
in the preparation step of the nano-silica sol particles, the temperature is rapidly increased to 80-120 ℃/hour.
From the above description, it can be seen by those skilled in the art that:
in the embodiment, the high-purity silica sol is hydrated and the high-purity silica sol hydration solution is subjected to anticoagulation treatment, so that the high-purity silica sol hydration solution can be assembled and grown at the interface of a six-membered heterocyclic compound forming template agent with stable physical property and a good space interface to form a hollow silica particle shape with unique characteristics and an ultra-large specific surface area, and a required product is obtained by suspension treatment, a spray freezing technology and a freeze-drying technology, so that a set of complete, novel and unique preparation method is formed, the whole preparation method is stable, simple and reliable in process, and has no pollution to the environment in the production process and excellent product performance, so that the preparation method has popularization and application values;
in the process, the embodiment firstly carries out hydration and special anticoagulation treatment on high-purity silica sol, creatively applies a suspension treatment technology, a spray freezing technology and a freeze-drying sublimation technology, removes part of water, organic volatile suspending agents and other volatile substances in the nano-silica sol frozen particles from the nano-silica sol frozen particles by freezing sublimation of a silica nanoparticle suspension, and forms cavities in the nano-silica sol frozen particles while removing the water and the organic volatile substances, thereby obtaining the hollow nano-microspheres with uniform surface appearance, ultrahigh specific surface area, needle-shaped protrusions or concave-convex points on the surface and rough surfaces, and providing quality guarantee for the application of the hollow nano-microspheres as adsorbents, catalysts or catalyst carriers and catalyst adhesives.
To further help understanding the technical solutions provided by the embodiments of the present invention, and the specific operation processes and effects that can be obtained by the embodiments of the present invention, the following further description is provided by specific examples.
Case 1
Adding silica sol with the mass percentage concentration of 50 percent, the purity of silica dioxide of more than 99.999 percent and the average particle size of silica sol particles of 30-40 nm into a high-pressure hydrothermal reaction kettle, then adding pure water with the mass percentage of 25 percent of the silica sol, starting stirring at the rotating speed of 200 revolutions per minute, and simultaneously heating the reaction kettle to 110-120 ℃ to obtain high-purity silica sol hydration liquid;
inputting ammonia gas with 1% of solid content of silica sol into a reaction kettle as an isolating agent, inputting a lubricant consisting of methane with 5 times of the volume of the silica sol and propane with 3 times of the volume of the silica sol, keeping the pressure in the reaction kettle at about 4MPa, and uniformly stirring to obtain an anticoagulant high-purity silica sol hydration liquid;
adding a forming template agent consisting of pyridine with the solid content of the silica sol of 0.1 percent and pyran with the solid content of the silica sol of 0.2 percent into the anticoagulated high-purity silica sol hydration solution under the stirring state, continuously heating to 180 ℃, keeping the pressure in the reaction kettle at about 6MPa for 0.5 hour, and leading the silica sol particles in the anticoagulated high-purity silica sol hydration solution to be directionally deposited, assembled and grown under the induction of the forming template agent to obtain nano silica sol particle mixed solution;
then, reducing the internal pressure of the reaction kettle to 0.1MPa, simultaneously reducing the temperature of the mixed solution of the nano-silica sol particles to 65 ℃, adding polyethylene glycol accounting for 0.5 percent of the mass of the silica sol as a suspending agent, uniformly stirring to obtain a suspension of the nano-silica sol particles, and recycling gas in the process;
continuously cooling the nano-silica sol particle suspension to room temperature, then spraying the nano-silica sol particle suspension into a quenching chamber, carrying out quick freezing, and freezing the nano-silica sol particle suspension to form nano-silica sol frozen particles at-65 ℃;
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles at the temperature of-65 ℃ until the water content is 45% or further reaches 8%, and obtaining a product containing dehydrated nano-silica sol particles, wherein sublimation removed substances can be recycled;
the product containing the dehydrated nano-silica sol particles is rapidly heated to normal temperature at a heating rate of 80 ℃/hour, and is simultaneously returned to normal pressure, so that the nano-silica sol particles for catalysis, which are provided in example 1 of the present invention in fig. 1, can be obtained as shown in a Scanning Electron Microscope (SEM) electron micrograph:
the product of silica hollow nano microsphere particles with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area is prepared by the following steps:
the water content of the product is 45 percent, and the product is a nano silicon dioxide sol particle colloid product for catalysis;
the nano-silica sol particle powder product with the water content of 8 percent is used for catalysis.
The detection shows that:
the nano-silica sol particles for catalysis in the product have an agglomeration rate of less than or equal to 0.1 percent, wherein the agglomeration rate represents the percentage of the number of particles, which is formed by bonding more than two particles with the average particle size, in the total number of the particles;
according to the solid content of the silicon dioxide, the specific surface area of the obtained nano silicon dioxide sol particles for catalysis is more than or equal to 420m 2 /g。
Case 2
Adding silica sol with the mass percentage concentration of 20 percent, the purity of silica dioxide of more than 99.999 percent and the average particle size of silica sol particles of 2-8 nm into a high-pressure hydrothermal reaction kettle, then adding pure water with the mass percentage of 55 percent of the silica sol, starting stirring at the rotating speed of 300 revolutions per minute, and simultaneously heating the reaction kettle to 110-120 ℃ to obtain high-purity silica sol hydration liquid;
inputting an isolating agent consisting of ammonia gas with 1 percent of solid content of silica sol and 0.5 percent of methylamine into a reaction kettle, inputting a lubricating agent consisting of methanol with 10 times of volume of the silica sol and methane with 5 times of volume of the silica sol, keeping the pressure in the reaction kettle at about 8MPa, and uniformly stirring to obtain an anticoagulant high-purity silica sol hydration solution;
adding a forming template agent consisting of pyridine with the solid content of the silica sol being 0.6% and pyrimidine with the solid content of the silica sol being 0.2% into the anticoagulated high-purity silica sol hydration solution under the stirring state, continuously heating to 160 ℃, and keeping the pressure in the reaction kettle at about 8MPa for 0.2 hour, so that silica sol particles in the anticoagulated high-purity silica sol hydration solution are directionally deposited, assembled and grown under the induction of the forming template agent, and a nano silica sol particle mixed solution is obtained;
then, reducing the internal pressure of the reaction kettle to 0.1MPa, simultaneously reducing the temperature of the mixed solution of the nano-silica sol particles to 60 ℃, adding polyethylene glycol with the mass percent of 1% of silica sol as a suspending agent, uniformly stirring to obtain a suspension of the nano-silica sol particles, and recycling gas in the process;
continuously cooling the nano-silica sol particle suspension to room temperature, then spraying the nano-silica sol particle suspension into a quenching chamber, rapidly freezing the nano-silica sol particle suspension to form nano-silica sol frozen particles at the temperature of 70 ℃ below zero;
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles at the temperature of-65 ℃ until the water content is 70% or further reaches 20-30%, and obtaining a product containing dehydrated nano-silica sol particles, wherein sublimation removed substances can be recycled;
rapidly heating the product containing the dehydrated nano-silica sol particles to normal temperature at a heating rate of 100 ℃/hour, and simultaneously recovering to normal pressure to obtain a product of the silica hollow nano-microsphere particles with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, namely a nano-silica sol particle product for catalysis, wherein:
the water content of the product is 70 percent, and the product is a nano silicon dioxide sol particle colloid product for catalysis;
the nano silicon dioxide sol particle powder product with the water content of 20-30 percent is used for catalysis.
The detection shows that:
the nano-silica sol particles for catalysis in the product have an agglomeration rate of less than or equal to 0.07 percent, wherein the agglomeration rate represents the percentage of the number of particles, which is formed by bonding more than two particles with the average particle size, in the total number of the particles;
according to the solid content of the silicon dioxide, the specific surface area of the obtained nano silicon dioxide sol particles for catalysis is more than or equal to 5000m 2 /g。
Case 3
Adding silica sol with the mass percentage concentration of 40%, the purity of silica dioxide of more than 99.999% and the average particle size of silica sol particles of 8-20 nm into a high-pressure hydrothermal reaction kettle, then adding pure water with the mass of 35% of the silica sol, starting stirring at the rotating speed of 1000 rpm, and simultaneously heating the reaction kettle to 110-120 ℃ to obtain high-purity silica sol hydration liquid;
methylamine with 1 percent of solid content of silica sol is input into a reaction kettle as an isolating agent, a lubricant consisting of 10 times of methanol and 3 times of propane in volume of the silica sol is input, the pressure in the reaction kettle is kept at about 4MPa, and the anticoagulant high-purity silica sol hydration liquid is obtained after uniform stirring;
adding a forming template agent consisting of pyridine with the solid content of the silica sol of 0.6 percent and pyran with the solid content of the silica sol of 0.1 percent into the anticoagulated high-purity silica sol hydration liquid under the stirring state, continuously heating to 150 ℃, keeping the pressure inside the reaction kettle at about 4MPa, and continuing for 0.4 hour to ensure that silica sol particles in the anticoagulated high-purity silica sol hydration liquid are directionally deposited, assembled and grown under the induction of the forming template agent to obtain nano silica sol particle mixed liquid;
then, reducing the internal pressure of the reaction kettle to 0.1MPa, simultaneously reducing the temperature of the mixed solution of the nano-silica sol particles to 70 ℃, adding vinyl acetate with the mass of 0.4 percent of that of the silica sol as a suspending agent, uniformly stirring to obtain a suspension of the nano-silica sol particles, and recycling gas in the process;
continuously cooling the nano-silica sol particle suspension to room temperature, then spraying the nano-silica sol particle suspension into a quenching chamber, rapidly freezing the nano-silica sol particle suspension to form nano-silica sol frozen particles at the temperature of-80 ℃;
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles at the temperature of minus 80 ℃ until the water content of the nano-silica sol frozen particles is 60-68% or further reaches 10-15%, and obtaining a product containing dehydrated nano-silica sol particles, wherein sublimation removed substances can be recycled;
rapidly heating the product containing the dehydrated nano-silica sol particles to normal temperature at a heating rate of 80 ℃/hour, and simultaneously recovering to normal pressure to obtain a product of the silica hollow nano-microsphere particles with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, namely a nano-silica sol particle product for catalysis, wherein:
the nano-silica sol particle colloid product with the water content of 60-68 percent for catalysis;
the nano silicon dioxide sol particle powder product with the water content of 10-15 percent is used for catalysis.
The detection shows that:
the nano-silica sol particles for catalysis in the product have an agglomeration rate of less than or equal to 0.4 percent, wherein the agglomeration rate represents the percentage of the number of particles, which is formed by bonding more than two particles with the average particle size, in the total number of the particles;
according to the solid content of the silicon dioxide, the specific surface area of the obtained nano silicon dioxide sol particles for catalysis is more than or equal to 500m 2 /g。
Case 4
Adding 45 mass percent of silica sol, the purity of the silica sol is more than 99.999 percent and the average particle size of the silica sol particles is 35-40 nm into a high-pressure hydrothermal reaction kettle, then adding pure water accounting for 45 mass percent of the silica sol, starting stirring at the rotating speed of 500 revolutions per minute, and simultaneously heating the reaction kettle to 110-120 ℃ to obtain high-purity silica sol hydration liquid;
inputting ammonia gas with 2 percent of solid content of silica sol into a reaction kettle as an isolating agent, inputting a lubricant consisting of methane with 5 times of the volume of the silica sol and propane with 3 times of the volume of the silica sol, keeping the pressure in the reaction kettle at about 5MPa, and uniformly stirring to obtain an anticoagulant high-purity silica sol hydration liquid;
adding a forming template agent consisting of pyridine with the solid content of the silica sol of 0.4 percent and pyran with the solid content of the silica sol of 0.2 percent into the anticoagulated high-purity silica sol hydration liquid under the stirring state, continuously heating to 160 ℃, keeping the pressure in the reaction kettle at about 3MPa for 1 hour, and leading the silica sol particles in the anticoagulated high-purity silica sol hydration liquid to be directionally deposited, assembled and grown under the induction of the forming template agent to obtain nano silica sol particle mixed liquid;
then, reducing the internal pressure of the reaction kettle to 0.1MPa, simultaneously reducing the temperature of the mixed solution of the nano-silica sol particles to 65 ℃, adding vinyl acetate with the mass of 0.25 percent of that of the silica sol as a suspending agent, uniformly stirring to obtain a suspension of the nano-silica sol particles, and recycling gas in the process;
continuously cooling the nano-silica sol particle suspension to room temperature, then spraying the nano-silica sol particle suspension into a quenching chamber, rapidly freezing the nano-silica sol particle suspension to form nano-silica sol frozen particles at the temperature of-65 ℃;
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles at the temperature of-65 ℃ until the water content is 50-55% or further reaches 10-12%, and obtaining a product containing dehydrated nano-silica sol particles, wherein sublimation removed substances can be recycled;
rapidly heating the product containing the dehydrated nano-silica sol particles to normal temperature at a heating rate of 120 ℃/h, and simultaneously recovering to normal pressure to obtain a product of the silica hollow nano-microsphere particles with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, namely a nano-silica sol particle product for catalysis, wherein:
the nano silicon dioxide sol particle colloid product with the water content of 50-55 percent for catalysis;
the nano silicon dioxide sol particle powder product with the water content of 10-12 percent for catalysis.
The detection shows that:
the nano-silica sol particles for catalysis in the product have an agglomeration rate of less than or equal to 0.1 percent, wherein the agglomeration rate represents the percentage of the number of particles, which is formed by bonding more than two particles with the average particle size, in the total number of the particles;
according to the solid content of the silicon dioxide, the specific surface area of the obtained nano silicon dioxide sol particles for catalysis is more than or equal to 470m 2 /g。
Effect embodiment:
1、CO 2 gas adsorption test
The test method comprises the following steps:
firstly, putting the nano silica sol particle powder product for catalysis with the water content of 8% provided in example 1 of the present embodiment into an adsorption reaction kettle, sealing, vacuumizing, heating to 180 ℃, maintaining for 8 hours, and cooling to room temperature;
then CO is introduced 2 Gas injection adsorption reactionIn the reaction kettle, respectively adsorbing CO in the reaction kettle by using a gas chromatographic analyzer 2 Detecting gas, displaying the detection result by computer system, and detecting CO before and after adsorption 2 Calculation of Change value of gas volume fraction on CO by Nano silica Sol particles for catalysis provided in case 1 2 The amount of gas adsorbed.
And (3) test results:
FIG. 2 shows the combination of nano-silica sol particles for catalysis with CO in example 1 of the present invention 2 It can be seen in the isothermal adsorption diagram of the gas:
at room temperature, the nano silica sol particles for catalysis provided in example 1 are in CO 2 Relative pressure of gas is 900mmHg, it is relative to CO 2 The adsorption capacity of the gas can reach 0.85mmol/g, which shows that the nano silica sol particles for catalysis provided in example 1 have great adsorption force, and simultaneously show that the nano silica sol particles for catalysis have great specific surface area and huge porosity, and can be used as good adsorbents, adsorption catalysts and catalyst carriers to meet related applications.
2. Catalyst support test
The test method comprises the following steps:
preparing a catalyst: adding the dried and dispersed titanium dioxide powder with the particle size of 5nm into water for dissolving to obtain a nano-scale photocatalytic solution, adding the photocatalytic solution into the nano-silica sol particle colloid product for catalysis with the water content of 70% provided by the embodiment 2, stirring and mixing uniformly, cleaning and drying to obtain the photocatalytic silica particles, and then carrying out organic matter adsorption effect test and catalytic efficiency test on the prepared photocatalytic silica particles, wherein:
the organic matter adsorption effect test is that the photocatalytic silicon dioxide particles are used for degrading organic sewage under the same condition, and the organic sewage is graded with the same water sample which is not adsorbed by the photocatalytic silicon dioxide particles through visual observation of the water body definition;
the catalytic efficiency adopts the degradation rate of Total Organic Carbon (TOC) in water as a judgment standard, the degradation rate test of the Total Organic Carbon (TOC) in water is to firstly measure the total organic carbon content of organic sewage by adopting a TOC detector, then the TOC value of a treated water sample is measured after the water sample is treated by adopting the photocatalytic silicon dioxide particles, and then the TOC degradation rate of the photocatalytic silicon dioxide particles to the organic sewage is calculated by the following formula;
TOC degradation rate% = (1-TOC content of water sample after treatment/TOC content of water sample before treatment) × 100%.
And (3) test results:
as shown in table 1.
TABLE 1
From table 1, it can be seen that:
the titanium dioxide photocatalyst prepared by using the nano silica sol particle colloid product for catalysis with the water content of 70% as the catalyst carrier provided in example 2 has good adsorbability on organic sewage and excellent TOC degradation rate, and the titanium dioxide photocatalyst is simple and convenient to manufacture and has great popularization and application values.
3. Catalyst Binder test
The test method comprises the following steps:
preparation of catalyst sample:
dissolving ammonium molybdate/cobalt nitrate/nickel nitrate/ferric nitrate/bismuth nitrate/potassium nitrate in an acidic solution according to a proportion to obtain a nitrate suspension, evaporating the obtained nitrate suspension to remove water to obtain a nitrate solid, and crushing the nitrate solid to below 250 micrometers to obtain a catalyst active component;
mixing the nano silica sol particle powder for catalysis with the water content of 10-15% and the active components of the catalyst, which are prepared in different proportions in the embodiment 3, and uniformly stirring to prepare a mixture of the active components of the catalyst and the silica sol;
adding silica-alumina carrier spheres with the average particle size of 4mm into a rotary drum granulation device, wetting the surfaces of the silica-alumina carrier spheres by deionized water, and then adding the catalyst active component-silica sol mixture into a hot air environment to prepare a supported catalyst, namely propylene oxidation catalyst particles;
and roasting the propylene oxidation catalyst particles for 8 hours at 400 ℃ in an air atmosphere to obtain the required propylene oxidation catalyst.
And (3) testing performance and effect:
testing the catalyst pulverization degree:
vertically placing a stainless steel reaction tube with the length of 5000mm and the inner diameter of 25mm, blocking a lower port of the reaction tube by using a stainless steel receiving plate with the thickness of 1mm, pouring 50g of the propylene oxidation catalyst into the reaction tube from an upper port of the reaction tube, taking out the catalyst from the receiving plate at the lower port of the reaction tube to obtain a tubular catalyst, screening the obtained tubular catalyst by using a screen with the aperture of 5mm, and evaluating the strength of the catalyst by using a catalyst pulverization degree value obtained by the following formula, wherein the higher value means the higher strength of the catalyst;
catalyst pulverization degree (%) = [ (mass g of the catalyst retained on the screen through the tube)/50g ]. Times 100%.
And (3) testing catalytic efficiency:
the propylene oxidation catalyst was packed in a reaction tube at a space velocity of 1500m 3 A raw material gas composed of 8% of propylene, 13% of oxygen, 6% of water vapor and a nitrogen gas in a participating volume was introduced at a flow rate per hour to carry out a gas phase oxidation reaction of propylene to produce acrylic acid, and the catalytic efficiency of the propylene oxidation catalyst was determined from the ratio of acrylic acid in the product to the ratio of propylene in the raw material gas.
And (3) test results: as shown in table 2.
TABLE 2
From table 2, it can be seen that:
the propylene oxidation catalyst prepared by using the nano silica sol particle powder product for catalysis with the water content of 10-15% provided in example 3 as the adhesive of the catalyst can not only significantly improve the strength of the catalyst, but also significantly improve the reaction activity, i.e. the catalytic efficiency of the catalyst, i.e. greatly improve the yield of the reaction, and obtain unexpected effects.
In summary, it can be seen that:
firstly, the preparation method of the nano-silica sol particles for catalysis provided by the embodiment of the invention comprises the steps of preparation of high-purity silica sol hydration liquid, preparation of anticoagulant high-purity silica sol hydration liquid, preparation of nano-silica sol particle mixed liquid, preparation of nano-silica sol particle suspension, preparation of nano-silica sol frozen particles, preparation of nano-silica sol particle powder and the like, so that a product of the hollow nano-silica microsphere particles with high dispersity, wide adaptability, rough surface morphology of particles with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area is obtained, and can be used as an adsorbent, a catalyst or a catalyst carrier, a catalyst adhesive and the like for relevant application;
secondly, the embodiment of the invention carries out rehydration and special anticoagulation treatment on the high-purity silica sol, creatively applies a suspension treatment technology, a spray freezing technology and a freeze-drying sublimation technology, removes part of moisture and various organic volatile auxiliaries in the nano-silica sol frozen particles by freezing sublimation of the silica nano-particle suspension, and forms cavities in the nano-silica sol frozen particles while removing the moisture and the organic volatile auxiliaries, thereby obtaining the hollow nano-microspheres with uniform surface appearance, ultrahigh specific surface area, good surface acicular protrusions or concave-convex points growing rough surfaces, and providing quality assurance for the application of the hollow nano-microspheres as an adsorbent, a catalyst or a catalyst carrier and a catalyst adhesive;
and the preparation method of the nano-silica sol particles for catalysis provided by the embodiment of the invention is novel and unique, the whole preparation method is stable, simple and reliable in process, free from environmental pollution in the production process, and excellent in product performance, so that the preparation method has great popularization and application values.
During the description of the above description:
the description of the terms "present embodiment," like "\8230; \8230"; "shown," "further," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention, and that in this description, an illustrative representation of the above-described term is not necessarily for the same embodiment or example, and that the particular feature, structure, material, or characteristic described, etc., may be combined or coupled in any suitable manner in any one or more embodiments or examples, and further that different embodiments or examples and features of different embodiments or examples described in this description may be combined or coupled by one of ordinary skill in the art without creating a conflict.
It should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the above embodiments can be modified, or some or all of the technical features can be equivalently replaced, and the modifications or the replacements do not make the essence of the corresponding technical solutions depart from the technical solutions of the embodiments of the present invention, and the person of ordinary skill in the art can make insubstantial improvements, modifications or replacements according to the content of the present specification, and all of the technical solutions are within the scope of the present invention as claimed.
Claims (10)
1. A method for preparing nano silica sol particles for catalysis is characterized by comprising the following steps:
the method comprises the following steps of preparing a high-purity silica sol hydration solution, preparing an anticoagulant high-purity silica sol hydration solution, preparing a nano-silica sol particle mixed solution, preparing a nano-silica sol particle suspension, preparing nano-silica sol frozen particles and preparing nano-silica sol particles, wherein the method comprises the following steps of:
the preparation method of the high-purity silica sol hydration solution comprises the following steps:
adding a high-purity silica sol solution into a high-pressure reaction device, then adding pure water with the mass of 25-55% of that of the high-purity silica sol solution, stirring and heating to above the boiling point of water to enable silica sol particles of the high-purity silica sol to be hydrated, refined and dissolved again to obtain the high-purity silica sol hydration solution;
the preparation method of the anticoagulant high-purity silica sol hydration solution specifically comprises the following steps:
under a high pressure state, adding an isolating agent consisting of ammonia gas and/or alkaline volatile organic compounds and a lubricant consisting of micromolecular volatile organic compounds or polyethylene glycol into the high-purity silica sol hydration liquid, and uniformly stirring to prevent silica sol particles in the high-purity silica sol hydration liquid from being adhered and store the smooth particles to obtain the anticoagulation high-purity silica sol hydration liquid;
the preparation method of the nano-silica sol particle mixed solution specifically comprises the following steps:
adding a forming template agent consisting of a hexabasic organic heterocyclic compound into the anticoagulation high-purity silica sol hydration solution at a temperature above the boiling point of water and under high pressure and in a stirring state, so that silica sol particles in the anticoagulation high-purity silica sol hydration solution are directionally deposited, assembled and grown on the hexabasic organic heterocyclic compound interface under the induction of the forming template agent to obtain nano silica sol particle mixed solution;
the preparation method of the nano silica sol particle suspension specifically comprises the following steps:
reducing the temperature of the mixed solution of the nano-silica sol particles to a temperature range below the boiling point of water and above room temperature, simultaneously reducing the environmental pressure of the mixed solution of the nano-silica sol particles, then adding a suspending agent consisting of organic volatile substances, and stirring to prepare a suspension of the nano-silica sol particles;
the preparation method of the nano-silica sol frozen particles specifically comprises the following steps:
cooling the nano-silica sol particle suspension to room temperature, and then spraying the nano-silica sol particle suspension into a quenching chamber to rapidly freeze the nano-silica sol particle suspension to obtain nano-silica sol frozen particles;
the preparation method of the nano silica sol particles specifically comprises the following steps:
carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 70%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the nano-silica sol frozen particles to normal pressure to obtain a product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano microspheres with needle-shaped protrusions or concave-convex points and ultrahigh specific surface area, and the product is colloid with the water content less than or equal to 70%; or
And carrying out vacuum sublimation dehydration on the nano-silica sol frozen particles until the water content is less than or equal to 30%, then heating the nano-silica sol frozen particles to normal temperature by adopting a rapid heating mode, and simultaneously recovering the nano-silica sol particles to normal pressure to obtain the product of the nano-silica sol particles for catalysis, wherein the silica sol particles in the product of the nano-silica sol particles for catalysis are hollow silica sol nano microspheres with needle-shaped protrusions or concave-convex points, rough surface appearance and ultrahigh specific surface area, and the product is particle powder with the water content less than or equal to 30%.
2. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
the high-purity silica sol has the mass percentage concentration of 20-50 percent of silica, the purity of the silica is more than 99.999 percent, and the average particle size of silica sol particles is 2-40 nm.
3. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
the isolating agent is composed of low molecular amine compounds, the lubricant is composed of lower alcohol or low molecular alkane, and the suspending agent is selected from low molecular and low viscosity alcohol or ester polymers.
4. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
the release agent is any one of ammonia gas and methylamine or a mixture of the ammonia gas and the methylamine, the lubricant is a mixture composed of any two of methanol, methane or propane, the suspending agent is any one of polyethylene glycol and vinyl acetate, and the molding template is a mixture composed of any two of pyridine, pyrimidine and pyran.
5. The method for preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
the separant is ammonia gas with the solid content of 1-2% and/or methylamine with the solid content of 0.5-1% of the high-purity silica sol;
the lubricant is a mixture of any two of 10 times of methanol, 5 times of methane or 3 times of propane by volume of the high-purity silica sol;
the suspending agent is polyethylene glycol accounting for 0.5 to 1 percent of the mass of the high-purity silica sol or vinyl acetate accounting for 0.1 to 0.4 percent of the mass of the high-purity silica sol;
the forming template is a mixture of any two of pyridine with the solid content of 0.1-0.6%, pyrimidine with the solid content of 0.2-0.45% or pyran with the solid content of 0.1-0.2%.
6. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
in the preparation step of the high-purity silica sol hydration solution, the heating temperature is 110-120 ℃, and the stirring speed is 200-1000 r/min.
7. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
in the step of preparing the mixed solution of the nano-silica sol particles, the temperature above the boiling point of water means that the temperature of the anticoagulated high-purity silica sol hydration solution is maintained at 120-180 ℃, the high pressure means that the anticoagulated high-purity silica sol hydration solution is in a pressure environment of 2-8 MPa, and the silica sol particles are directionally deposited and assembled on the interface of the hexahydric organic heterocyclic compound under the induction of the molding template agent and grow for 0.1-1 hour.
8. The method of preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
in the step of preparing the nano-silica sol particle suspension, the temperature interval between the boiling point and the room temperature is that the temperature of the nano-silica sol particle mixed solution is reduced to 60 to 80 ℃, and the environmental pressure of the nano-silica sol particle mixed solution is reduced to 0.1 to 0.5MPa.
9. The method for preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
in the preparation step of the nano-silica sol frozen particles, the quenching chamber is an operation space cooled by liquid nitrogen, and the temperature of the nano-silica sol frozen particles is below minus 60 ℃.
10. The method for preparing nano silica sol particles for catalysis as claimed in claim 1, wherein:
in the preparation step of the nano-silica sol particles, the temperature rise rate of the rapid temperature rise is 80-120 ℃/hour.
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