JP2010162443A - Platinum black powder, platinum black colloid, and methods for producing them - Google Patents
Platinum black powder, platinum black colloid, and methods for producing them Download PDFInfo
- Publication number
- JP2010162443A JP2010162443A JP2009005161A JP2009005161A JP2010162443A JP 2010162443 A JP2010162443 A JP 2010162443A JP 2009005161 A JP2009005161 A JP 2009005161A JP 2009005161 A JP2009005161 A JP 2009005161A JP 2010162443 A JP2010162443 A JP 2010162443A
- Authority
- JP
- Japan
- Prior art keywords
- platinum
- platinum black
- colloid
- nanocolloid
- black powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 title claims abstract description 280
- 239000000084 colloidal system Substances 0.000 title claims abstract description 83
- 239000000843 powder Substances 0.000 title claims abstract description 55
- 238000000034 method Methods 0.000 title claims description 22
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 72
- 239000002253 acid Substances 0.000 claims abstract description 50
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 37
- 238000005406 washing Methods 0.000 claims abstract description 27
- 238000001035 drying Methods 0.000 claims abstract description 21
- 239000003638 chemical reducing agent Substances 0.000 claims abstract description 19
- 239000007791 liquid phase Substances 0.000 claims abstract description 11
- 238000001914 filtration Methods 0.000 claims abstract description 10
- 238000004519 manufacturing process Methods 0.000 claims description 54
- 239000002245 particle Substances 0.000 claims description 38
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 31
- 239000001301 oxygen Substances 0.000 claims description 31
- 229910052760 oxygen Inorganic materials 0.000 claims description 31
- 230000009467 reduction Effects 0.000 claims description 19
- 238000009826 distribution Methods 0.000 claims description 16
- 239000000460 chlorine Substances 0.000 claims description 14
- 229910052801 chlorine Inorganic materials 0.000 claims description 14
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 13
- 229910052783 alkali metal Inorganic materials 0.000 claims description 13
- 150000001340 alkali metals Chemical class 0.000 claims description 13
- 239000011148 porous material Substances 0.000 claims description 13
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 11
- 229910001882 dioxygen Inorganic materials 0.000 claims description 11
- 239000006185 dispersion Substances 0.000 claims description 11
- 239000002904 solvent Substances 0.000 claims description 11
- 238000007664 blowing Methods 0.000 claims description 9
- 238000000921 elemental analysis Methods 0.000 claims description 8
- 239000012535 impurity Substances 0.000 claims description 7
- 238000002296 dynamic light scattering Methods 0.000 claims description 5
- 239000003586 protic polar solvent Substances 0.000 claims description 4
- 238000000634 powder X-ray diffraction Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 4
- 230000003197 catalytic effect Effects 0.000 abstract description 2
- 239000008213 purified water Substances 0.000 abstract 1
- 238000003756 stirring Methods 0.000 description 27
- 239000003054 catalyst Substances 0.000 description 21
- 239000000243 solution Substances 0.000 description 21
- 238000006722 reduction reaction Methods 0.000 description 20
- 239000007864 aqueous solution Substances 0.000 description 16
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 16
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 14
- 239000011164 primary particle Substances 0.000 description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 11
- 238000006243 chemical reaction Methods 0.000 description 11
- 239000007788 liquid Substances 0.000 description 11
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000011734 sodium Substances 0.000 description 9
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 8
- 150000001412 amines Chemical class 0.000 description 8
- 235000019253 formic acid Nutrition 0.000 description 8
- 238000009616 inductively coupled plasma Methods 0.000 description 8
- 239000002105 nanoparticle Substances 0.000 description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 6
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- 239000013078 crystal Substances 0.000 description 6
- 239000000706 filtrate Substances 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 230000003472 neutralizing effect Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 239000000725 suspension Substances 0.000 description 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 239000004809 Teflon Substances 0.000 description 4
- 229920006362 Teflon® Polymers 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 229960000583 acetic acid Drugs 0.000 description 4
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 239000012298 atmosphere Substances 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 229920000554 ionomer Polymers 0.000 description 4
- 239000012528 membrane Substances 0.000 description 4
- 238000011946 reduction process Methods 0.000 description 4
- 239000007921 spray Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- 241000872198 Serjania polyphylla Species 0.000 description 3
- YKIOKAURTKXMSB-UHFFFAOYSA-N adams's catalyst Chemical compound O=[Pt]=O YKIOKAURTKXMSB-UHFFFAOYSA-N 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 238000007605 air drying Methods 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 239000012065 filter cake Substances 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 239000011163 secondary particle Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 241000894007 species Species 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 2
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- 229910002848 Pt–Ru Inorganic materials 0.000 description 2
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 230000005587 bubbling Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- XBDQKXXYIPTUBI-UHFFFAOYSA-N dimethylselenoniopropionate Natural products CCC(O)=O XBDQKXXYIPTUBI-UHFFFAOYSA-N 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000012362 glacial acetic acid Substances 0.000 description 2
- -1 hexahydroxyplatinum (IV) Chemical compound 0.000 description 2
- 238000005984 hydrogenation reaction Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000002082 metal nanoparticle Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 2
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 2
- 229910052707 ruthenium Inorganic materials 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910021642 ultra pure water Inorganic materials 0.000 description 2
- 239000012498 ultrapure water Substances 0.000 description 2
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 1
- FLDSMVTWEZKONL-AWEZNQCLSA-N 5,5-dimethyl-N-[(3S)-5-methyl-4-oxo-2,3-dihydro-1,5-benzoxazepin-3-yl]-1,4,7,8-tetrahydrooxepino[4,5-c]pyrazole-3-carboxamide Chemical compound CC1(CC2=C(NN=C2C(=O)N[C@@H]2C(N(C3=C(OC2)C=CC=C3)C)=O)CCO1)C FLDSMVTWEZKONL-AWEZNQCLSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 206010016275 Fear Diseases 0.000 description 1
- 229920003935 Flemion® Polymers 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 229910013553 LiNO Inorganic materials 0.000 description 1
- 229920000557 Nafion® Polymers 0.000 description 1
- 241000705939 Shortia uniflora Species 0.000 description 1
- 235000002597 Solanum melongena Nutrition 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001339 alkali metal compounds Chemical class 0.000 description 1
- 229910001413 alkali metal ion Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 description 1
- 239000011668 ascorbic acid Substances 0.000 description 1
- 235000010323 ascorbic acid Nutrition 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000010411 electrocatalyst Substances 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 239000000374 eutectic mixture Substances 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- UQSQSQZYBQSBJZ-UHFFFAOYSA-N fluorosulfonic acid Chemical compound OS(F)(=O)=O UQSQSQZYBQSBJZ-UHFFFAOYSA-N 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000000877 morphologic effect Effects 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 239000005518 polymer electrolyte Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 235000019260 propionic acid Nutrition 0.000 description 1
- IUVKMZGDUIUOCP-BTNSXGMBSA-N quinbolone Chemical compound O([C@H]1CC[C@H]2[C@H]3[C@@H]([C@]4(C=CC(=O)C=C4CC3)C)CC[C@@]21C)C1=CCCC1 IUVKMZGDUIUOCP-BTNSXGMBSA-N 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 159000000000 sodium salts Chemical class 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
- B01J23/42—Platinum
-
- B01J35/23—
-
- B01J35/393—
-
- B01J35/613—
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/12—Oxidising
- B01J37/14—Oxidising with gases containing free oxygen
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/16—Reducing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F1/05—Metallic powder characterised by the size or surface area of the particles
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/16—Making metallic powder or suspensions thereof using chemical processes
- B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
- B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
- H01M4/925—Metals of platinum group supported on carriers, e.g. powder carriers
- H01M4/926—Metals of platinum group supported on carriers, e.g. powder carriers on carbon or graphite
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Abstract
Description
本発明は高い触媒活性を有する高比表面積の白金ブラック粉末及び白金ブラックのコロイド並びにそれらの製造方法に関する。 The present invention relates to a high specific surface area platinum black powder having high catalytic activity, a colloid of platinum black, and a method for producing them.
白金ブラックは、ファィンケミカルの水素化用触媒又は酸化用触媒として古くから使用されてきた。また、近年、燃料電池、電解セル及び電気化学的センサの用途におけるガス拡散電極用触媒として使用されてきた。 Platinum black has long been used as a catalyst for hydrogenation or oxidation of fin chemicals. In recent years, it has been used as a catalyst for gas diffusion electrodes in applications of fuel cells, electrolytic cells, and electrochemical sensors.
カーボン又はアルミナ等担体に担持された担持白金触媒と比べて、白金ブラックには、担持白金触媒には無い次のようなメリットが指摘されていた。即ち、（１）活性種である白金ナノ粒子が担体の細孔内部に埋設しない為に白金の利用効率を高められること、（２）担持触媒は、反応条件によっては担体の腐食、劣化のおそれがあり、これが担持された白金ナノ粒子の凝集を促進する場合が有るが、白金ブラックには、これらのおそれが無いこと、（３）特に電極触媒の用途では、触媒層の厚さを担持触媒の場合と比べて大幅に薄く形成できることから物質輸送を良くし、且つ触媒層を電解質膜の近傍に局在化できるために高性能な電極を形成できること、などが挙げられる。 Compared to a supported platinum catalyst supported on a carrier such as carbon or alumina, platinum black has been pointed out as having the following merits that the supported platinum catalyst does not have. That is, (1) platinum utilization efficiency is improved because platinum nanoparticles as active species are not embedded in the pores of the support, and (2) the supported catalyst may corrode or deteriorate the support depending on the reaction conditions. This may promote the aggregation of the supported platinum nanoparticles, but platinum black does not have these fears, and (3) the catalyst layer thickness is particularly important for electrode catalyst applications. Since it can be formed much thinner than the above case, it is possible to improve material transport and to localize the catalyst layer in the vicinity of the electrolyte membrane, so that a high-performance electrode can be formed.
白金ブラックの製法とその製法で得られる白金ブラックのＢＥＴ比表面積（以下、「比表面積」ともいう。）に関しては従来から多数の報告がある。例えば、Ｈ２ＰｔＣｌ６水溶液を濃ＫＯＨ水溶液存在下、室温でホルマリン還元して比表面積８ｍ２／ｇの白金ブラックが得られている（例えば、非特許文献１を参照。）。また、塩化白金酸Ｈ２ＰｔＣｌ６・６Ｈ２Ｏのホルマリン水溶液と、予め核形成のために調製された塩化白金酸Ｈ２ＰｔＣｌ６・６Ｈ２Ｏと炭酸ナトリウムＮａ２ＣＯ３とホルマリンとの混合溶液とを９０℃加熱中のＮａＯＨ水溶液に同時に添加して、比表面積２２．２〜３１．７ｍ２／ｇの白金ブラックを得たとの報告がある（例えば、非特許文献２を参照。）。また、Ｈ２ＰｔＣｌ６水溶液を４０℃で１０％ヒドラジン水溶液で処理して比表面積１０ｍ２／ｇの白金ブラックを得ている（例えば、非特許文献３を参照。）。更に、ヘキサヒドロキソ白金(ＩＶ)酸の希硝酸溶液に過剰の脱イオン水を添加後、７０℃に加熱し二酸化白金のオレンジ色の懸濁液を得、これに濃アンモニア水を添加してｐＨ５に中和し、次いで蟻酸で還元し、結晶子サイズ５．３ｎｍの白金ブラックを得たとの報告がある（例えば、特許文献１を参照。）。 There have been many reports on the production method of platinum black and the BET specific surface area (hereinafter also referred to as “specific surface area”) of platinum black obtained by the production method. For example, platinum black having a specific surface area of 8 m 2 / g is obtained by reducing formal solution of H 2 PtCl 6 aqueous solution at room temperature in the presence of concentrated KOH aqueous solution (see, for example, Non-Patent Document 1). The mixing of the aqueous formalin solution of chloroplatinic acid H 2 PtCl 6 · 6H 2 O, chloroplatinic acid H 2 PtCl 6 · 6H 2 O and sodium carbonate Na 2 CO 3 prepared for pre-nucleation formalin There is a report that platinum black having a specific surface area of 22.2 to 31.7 m 2 / g was obtained by simultaneously adding the solution to a NaOH aqueous solution being heated at 90 ° C. (see, for example, Non-Patent Document 2). In addition, H 2 PtCl 6 aqueous solution is treated with 10% hydrazine aqueous solution at 40 ° C. to obtain platinum black having a specific surface area of 10 m 2 / g (see, for example, Non-Patent Document 3). Further, after adding excess deionized water to a dilute nitric acid solution of hexahydroxoplatinum (IV) acid, the mixture was heated to 70 ° C. to obtain an orange suspension of platinum dioxide, and concentrated ammonia water was added thereto to adjust the pH to 5 And then reduced with formic acid to obtain platinum black having a crystallite size of 5.3 nm (for example, see Patent Document 1).
他方、溶融法では、（ＮＨ４）２ＰｔＣｌ６とＮａＮＯ３とを５００℃で溶融し、水洗後、二酸化白金粉末ＰｔＯ２を得て、これを水に投入して分散後、Ｈ２バブリングで還元して、比表面積２４〜２９ｍ２／ｇの白金ブラックを得ている（例えば、非特許文献４を参照。）。また、ＫＮＯ３とＬｉＮＯ３の共融点混合物にヘキサヒドロキシ白金(ＩＶ)酸を加えて４５０℃で溶融し、洗浄後得られた二酸化白金粉末を水に分散し、３％ＮａＯＨと６％ヒドラジン水溶液で還元して比表面積４７〜５２ｍ２／ｇの白金ブラックを得る方法が報告されている（例えば、特許文献２を参照。）。特許文献２には、また上記と同様な溶融法で、比表面積８４〜８７ｍ２／ｇを有する、白金とルテニウムの原子比５０:５０の合金粉末が得られるとの記載がある。 On the other hand, in the melting method, (NH 4 ) 2 PtCl 6 and NaNO 3 are melted at 500 ° C., washed with water to obtain platinum dioxide powder PtO 2 , which is poured into water, dispersed, and then subjected to H 2 bubbling. Reduction to obtain platinum black having a specific surface area of 24 to 29 m 2 / g (see, for example, Non-Patent Document 4). In addition, hexahydroxyplatinum (IV) acid is added to the eutectic mixture of KNO 3 and LiNO 3 and melted at 450 ° C., and the platinum dioxide powder obtained after washing is dispersed in water. 3% NaOH and 6% hydrazine aqueous solution A method for obtaining platinum black having a specific surface area of 47 to 52 m 2 / g by reduction is reported (for example, see Patent Document 2). Patent Document 2 also describes that an alloy powder having a specific surface area of 84 to 87 m 2 / g and an atomic ratio of 50:50 of platinum and ruthenium can be obtained by the same melting method as described above.
担持白金触媒と比べて白金ブラックには前記のメリットが指摘されていたが、これまで高比表面積の白金ブラック触媒を製造することが難しいため、比表面積が低く、粒子の凝集した白金ブラックしか得られなかった。前記のとおり非特許文献１では比表面積が８ｍ２／ｇであり、非特許文献２では比表面積が２２．２〜３１．７ｍ２／ｇであり、非特許文献３では比表面積が１０ｍ２／ｇである。また、特許文献２には比表面積が８４〜８７ｍ２／ｇの白金とルテニウムの合金粉末が記載されているが、７０ｍ２／ｇを超える高比表面積の白金粉末の製造例は記載されていない。 The above-mentioned merits have been pointed out with platinum black compared to supported platinum catalysts. However, since it has been difficult to produce platinum black catalysts with a high specific surface area, only platinum black with a low specific surface area and aggregated particles can be obtained. I couldn't. As described above, non-patent document 1 has a specific surface area of 8 m 2 / g, non-patent document 2 has a specific surface area of 22.2 to 31.7 m 2 / g, and non-patent document 3 has a specific surface area of 10 m 2 / g. g. Further, although Patent Document 2 specific surface area are described alloy powder of platinum and ruthenium 84~87m 2 / g, Production Example of the platinum powder having a high specific surface area greater than 70m 2 / g is not described .
そもそも、貴金属のナノ粒子の場合、１次粒子径をＤ,ｄ（数１）とすると、貴金属ナノ粒子１個当たりの体積ｖは、（数２）となる。貴金属の密度をρ（ｇ／ｃｍ３）とすると、粒子１個の質量ｗは、（数３）と表わされる。
（数１）ｄ（ｃｍ）＝Ｄ（ｎｍ）×１０‐７
（数２）ｖ（ｃｍ３）＝（４π／３）（ｄ／２）３
＝ （４π／３）〔（Ｄ×１０‐７）／２〕３
（数３）ｗ＝ρ×ｖ＝ρ×（４π／３）〔（Ｄ×１０‐７）／２〕３
In the first place, in the case of noble metal nanoparticles, if the primary particle diameter is D and d (Equation 1), the volume v per noble metal nanoparticle is (Equation 2). When the density of the noble metal is ρ (g / cm 3 ), the mass w of one particle is expressed as (Equation 3).
(Equation 1) d (cm) = D (nm) × 10 −7
(Equation 2) v (cm 3 ) = (4π / 3) (d / 2) 3
= (4π / 3) [(D × 10 −7 ) / 2] 3
(Expression 3) w = ρ × v = ρ × (4π / 3) [(D × 10 −7 ) / 2] 3
他方、粒子１個当たりの表面積ｓは、（数４）と表され、したがって、比表面積Ｓは、（数５）であるから、比表面積Ｓと１次粒子径Ｄとの間には、（数６）なる関係式が成立する。
（数４）ｓ（ｃｍ２）＝４π（ｄ／２）２＝４π〔（Ｄ×１０‐７）／２〕〕２
（数５）Ｓ（ｍ２／ｇ）＝ｓ×１０‐４／ｗ
（数６）Ｓ＝ｓ×１０‐４／ｗ＝〔ｓ×１０‐４／（ρｖ）〕＝１０‐４｛４π（ｄ／２）２／〔ρ（４π／３）（ｄ／２）３〕｝＝１０‐４〔３／ρ（ｄ／２）〕＝１０‐４〔６／ρ（Ｄ×１０‐７）〕=６×１０３／ρＤ
On the other hand, the surface area s per particle is expressed by (Equation 4), and therefore the specific surface area S is (Equation 5). Therefore, between the specific surface area S and the primary particle diameter D, ( The relational expression (6) holds.
(Equation 4) s (cm 2 ) = 4π (d / 2) 2 = 4π [(D × 10 −7 ) / 2]] 2
(Expression 5) S (m 2 / g) = s × 10 −4 / w
(Formula 6) S = s × 10 −4 / w = [s × 10 −4 / (ρv)] = 10 −4 {4π (d / 2) 2 / [ρ (4π / 3) (d / 2) 3 ]} = 10 −4 [3 / ρ (d / 2)] = 10 −4 [6 / ρ (D × 10 −7 )] = 6 × 10 3 / ρD
白金の場合、ρ＝２１．４５ｃｍ３／ｇだから、（数７）なる関係が得られる。また、Ｒｕの場合、ρ＝１２．１ｃｍ３／ｇだから、（数８）なる関係が得られる。
（数７）Ｓ（ｍ２／ｇ）＝（６×１０４）／２１．４５／Ｄ＝２８０／Ｄ（ｎｍ）
（数８）Ｓ（ｍ２／ｇ）＝（６×１０４）／１２．１／Ｄ＝４９６／Ｄ（ｎｍ）
In the case of platinum, since ρ = 21.45 cm 3 / g, the relationship of (Equation 7) is obtained. In the case of Ru, since ρ = 12.1 cm 3 / g, the relationship of (Equation 8) is obtained.
(Expression 7) S (m 2 / g) = (6 × 10 4 ) /2.45/D=280/D (nm)
(Equation 8) S (m 2 / g) = (6 × 10 4 ) /12.1/D=496/D (nm)
即ち、１次粒子径が同じくＤ＝４.０ｎｍであっても、白金の比表面積は高々Ｓ＝７０ｍ２／ｇであるのに対し、ＲｕはＳ＝１２４ｍ２／ｇもの高い比表面積を有する。１次粒子径Ｄ＝４．０ｎｍで原子比１：１のＰｔ‐Ｒｕ合金ならば、１次粒子径Ｄ＝４．０ｎｍ
であっても比表面積は概算Ｓ＝９７ｍ２／ｇと比較的高い値になると推算される。
That is, even when the primary particle diameter is D = 4.0 nm, the specific surface area of platinum is at most S = 70 m 2 / g, whereas Ru has a specific surface area as high as S = 124 m 2 / g. . For a Pt—Ru alloy with a primary particle size D = 4.0 nm and an atomic ratio of 1: 1, the primary particle size D = 4.0 nm
Even so, the specific surface area is estimated to be a relatively high value of approximately S = 97 m 2 / g.
特許文献２の請求項及び明細書には、形式的に高い比表面積の白金ブラックの記載が読み取れるが、Ｐｔ‐Ｒｕ合金が主要な発明であり、７０ｍ２／ｇを超えるような高比表面積の白金ブラックの実施例は教示していない。 The claims and specifications of Patent Document 2 can read the description of platinum black with a high specific surface area formally, but Pt-Ru alloy is the main invention and has a high specific surface area exceeding 70 m 2 / g. Examples of platinum black are not taught.
上記のとおり、７０ｍ２／ｇを超えるような高比表面積の白金ブラック及びそれを得るための製造方法については実用化された従来技術としてほとんど存在せず、したがって、白金ブラックが有する前記の潜在的メリットが十分生かされることはなかった。そこで、本発明の目的は、７０ｍ２／ｇを超える高比表面積を有する高活性な白金ブラック触媒粉末、それを分散したコロイド、及びそれらの実用的な製造方法を提供することである。 As described above, platinum black having a high specific surface area exceeding 70 m 2 / g and a production method for obtaining the same have hardly existed as a prior art that has been put to practical use. The merit was not fully utilized. Accordingly, an object of the present invention is to provide a highly active platinum black catalyst powder having a high specific surface area exceeding 70 m 2 / g, a colloid in which it is dispersed, and a practical production method thereof.
本発明者らは、上記の課題を解決するために、鋭意検討した結果、製造中間体としてヘキサヒドロキソ白金酸のナノコロイドを用いることで高比表面積を有する白金ブラックができることを見出し、本発明を完成させた。すなわち、本発明に係る白金ブラック粉末は、８０ｍ２／ｇ以上の比表面積を有することを特徴とする。さらに本発明に係る白金ブラック粉末は、９０ｍ２／ｇ以上の比表面積を有することを特徴とする。また、本発明に係る白金ブラック粉末は、全細孔容積が０．０３８ｃｍ３／ｇ以上であることを特徴とする。 As a result of intensive investigations to solve the above problems, the present inventors have found that platinum black having a high specific surface area can be obtained by using a nanocolloid of hexahydroxoplatinic acid as a production intermediate. Completed. That is, the platinum black powder according to the present invention has a specific surface area of 80 m 2 / g or more. Furthermore, the platinum black powder according to the present invention is characterized by having a specific surface area of 90 m 2 / g or more. The platinum black powder according to the present invention is characterized in that the total pore volume is 0.038 cm 3 / g or more.
本発明に係る白金ブラック粉末では、元素分析による酸素の乾燥質量換算の含有率が３．５質量％以上７．０％質量以下であることが好ましい。 In the platinum black powder according to the present invention, it is preferable that the content of oxygen in terms of dry mass by elemental analysis is 3.5% by mass or more and 7.0% by mass or less.
本発明に係る白金ブラック粉末では、元素分析による不純物として含有される塩素及びアルカリ金属の乾燥質量換算の含有率が、いずれも５００ｐｐｍ以下であることが好ましい。 In the platinum black powder according to the present invention, it is preferable that the dry mass conversion contents of chlorine and alkali metal contained as impurities by elemental analysis are both 500 ppm or less.
本発明に係る白金ブラック粉末では、粉末法Ｘ線回折で検出される白金含有種が立方晶白金のみであり、そのＰｔ（２２０）結晶子サイズが３．０ｎｍ以下であることが好ましい。 In the platinum black powder according to the present invention, it is preferable that the platinum-containing species detected by powder X-ray diffraction is only cubic platinum, and the Pt (220) crystallite size is 3.0 nm or less.
本発明に係る白金ブラックのコロイドは、本発明に係る白金ブラック粉末がプロトン性極性溶媒に分散させられた白金ブラックのコロイドであって、動的光散乱法で測定される粒子径０．１ｎｍ〜１００００ｎｍの領域の粒度分布において、単一ピークの粒度分布曲線を有し、平均粒子径が２５０ｎｍ以下で、且つ多分散度指数が０．１５以下の粒度分布を有することを特徴とする。 The colloid of platinum black according to the present invention is a colloid of platinum black in which the platinum black powder according to the present invention is dispersed in a protic polar solvent, and the particle diameter measured by a dynamic light scattering method is 0.1 nm to The particle size distribution in the region of 10,000 nm has a particle size distribution curve having a single peak, an average particle size of 250 nm or less, and a polydispersity index of 0.15 or less.
本発明に係る白金ブラックのコロイドは、ゼータ電位がマイナス４０ｍＶ以下であることが好ましい。 The colloid of platinum black according to the present invention preferably has a zeta potential of minus 40 mV or less.
本発明に係る白金ブラック粉末の製造方法は、液相中にヘキサヒドロキソ白金酸のナノコロイドを生成させるナノコロイド生成工程と、前記ナノコロイドに還元剤を添加して前記ナノコロイドを還元し、白金含有コロイドを形成する還元工程と、前記白金含有コロイドをろ過し純水洗浄する洗浄工程と、洗浄した白金含有コロイドを乾燥する乾燥工程と、
を有することを特徴とする。
The method for producing a platinum black powder according to the present invention includes a nanocolloid generation step of generating a nanocolloid of hexahydroxoplatinic acid in a liquid phase, a reducing agent added to the nanocolloid to reduce the nanocolloid, A reduction step of forming a colloid-containing colloid, a washing step of filtering the platinum-containing colloid and washing with pure water, a drying step of drying the washed platinum-containing colloid,
It is characterized by having.
本発明に係る白金ブラック粉末の製造方法では、前記還元工程の後に、前記白金含有コロイドに空気乃至酸素ガスを吹き込む酸素処理工程をさらに有することが好ましい。 The method for producing platinum black powder according to the present invention preferably further includes an oxygen treatment step of blowing air or oxygen gas into the platinum-containing colloid after the reduction step.
本発明に係る白金ブラックコロイドの製造方法は、液相中にヘキサヒドロキソ白金酸のナノコロイドを生成させるナノコロイド生成工程と、前記ナノコロイドに還元剤を添加して前記ナノコロイドを還元し、白金含有コロイドを形成する還元工程と、前記白金含有コロイドをろ過し純水洗浄する洗浄工程と、洗浄した白金含有コロイドを溶媒に分散する分散工程と、を有することを特徴とする。 The method for producing a platinum black colloid according to the present invention includes a nanocolloid generating step of generating a nanocolloid of hexahydroxoplatinic acid in a liquid phase, a reducing agent added to the nanocolloid to reduce the nanocolloid, A reduction step of forming a colloid containing, a washing step of filtering the platinum-containing colloid and washing with pure water, and a dispersion step of dispersing the washed platinum-containing colloid in a solvent.
本発明に係る白金ブラックコロイドの製造方法では、前記還元工程の後に、前記白金含有コロイドに空気乃至酸素ガスを吹き込む酸素処理工程をさらに有することが好ましい。 The method for producing a platinum black colloid according to the present invention preferably further includes an oxygen treatment step of blowing air or oxygen gas into the platinum-containing colloid after the reduction step.
本発明に係る白金ブラック粉末は、７０ｍ２／ｇを超える高比表面積を有するため、高活性な白金ブラック触媒粉末として、前記の潜在的メリット、すなわち、（１）活性種である白金ナノ粒子が担体の細孔内部に埋設しない為に白金の利用効率を高められること、（２）担持触媒の担体が腐食、劣化するような反応条件においても、白金ブラックは腐食・劣化に対する耐久性が高いこと、（３）特に電極触媒の用途では、触媒層の厚さを担持触媒の場合と比べて大幅に薄く形成できることから物質輸送を良くし、且つ、触媒層を電解質膜の近傍に局在化できるために高性能な電極を形成できること、が実現可能である。本発明に係る白金ブラック粉末の製造方法によって、７０ｍ２／ｇを超える高比表面積のものが提供できる。本発明に係る白金ブラックはプロトン性極性溶媒に分散しやすく、こうして得られる本発明の白金ブラックのコロイドは、ゼータ電位の絶対値が大きく粒度分布がシャープな為、コロイドとしての安定性が高い。 Since the platinum black powder according to the present invention has a high specific surface area exceeding 70 m 2 / g, as the highly active platinum black catalyst powder, the above-mentioned potential merit, that is, (1) platinum nanoparticles which are active species are The platinum utilization efficiency can be improved because it is not embedded in the pores of the support, and (2) platinum black has high resistance to corrosion and deterioration even under reaction conditions where the support of the supported catalyst corrodes and deteriorates. (3) Especially in the use of an electrocatalyst, the thickness of the catalyst layer can be significantly reduced compared to the case of the supported catalyst, so that mass transport is improved and the catalyst layer can be localized in the vicinity of the electrolyte membrane. Therefore, it is possible to form a high-performance electrode. The method for producing platinum black powder according to the present invention can provide a high specific surface area exceeding 70 m 2 / g. The platinum black according to the present invention is easily dispersed in a protic polar solvent, and the thus obtained platinum black colloid of the present invention has a high absolute value of zeta potential and a sharp particle size distribution, and therefore has high stability as a colloid.
以下本発明について実施形態を示して詳細に説明するが本発明はこれらの記載に限定して解釈されない。本発明の効果を奏する限り、実施形態は種々の変形をしてもよい。 Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not construed as being limited to these descriptions. As long as the effect of the present invention is exhibited, the embodiment may be variously modified.
まず、本実施形態に係る白金ブラック粉末の製造方法について説明する。本実施形態に係る白金ブラック粉末の製造方法（第一形態）は、液相中にヘキサヒドロキソ白金酸のナノコロイドを生成させるナノコロイド生成工程と、ナノコロイドに還元剤を添加してナノコロイドを還元し、白金含有コロイドを形成する還元工程と、白金含有コロイドをろ過し純水洗浄する洗浄工程と、洗浄した白金含有コロイドを乾燥する乾燥工程と、を有する。 First, a method for producing platinum black powder according to the present embodiment will be described. The method for producing platinum black powder according to the present embodiment (first form) includes a nanocolloid generation step of forming a nanocolloid of hexahydroxoplatinic acid in a liquid phase, and a nanocolloid obtained by adding a reducing agent to the nanocolloid. A reduction step of reducing and forming a platinum-containing colloid, a washing step of filtering the platinum-containing colloid and washing with pure water, and a drying step of drying the washed platinum-containing colloid.
（ナノコロイド生成工程）
本工程で使用するヘキサヒドロキソ白金酸は、公知の物質であり、ヘキサヒドロキソ白金酸の製法も特許文献３又は４に教示される通り公知である。また特許文献５、６又は７が教示する如く、ヘキサヒドロキソ白金酸をアミン溶液に溶解し、可溶化することも公知である。
(Nano colloid production process)
Hexahydroxoplatinic acid used in this step is a known substance, and a method for producing hexahydroxoplatinic acid is also known as taught in Patent Document 3 or 4. It is also known that hexahydroxoplatinic acid is dissolved in an amine solution and solubilized, as taught by Patent Document 5, 6 or 7.
ヘキサヒドロキソ白金酸のナノコロイドは、ヘキサヒドロキソ白金酸のアミン溶液又はヘキサヒドロキソ白金酸のナトリウム塩若しくはカリウム塩の希薄溶液を調製し、十分激しく攪拌しながらこれに中和剤の希薄溶液を滴下若しくは噴霧添加することによって得られる。好ましくは、ヘキサヒドロキソ白金酸のアミン溶液である。または、中和剤の希薄溶液を十分激しく攪拌しながらこれにヘキサヒドロキソ白金酸のアミン溶液又はヘキサヒドロキソ白金酸ナトリウムの塩若しくはカリウム塩の希薄溶液を滴下若しくは噴霧添加することによって得られる。好ましくは、ヘキサヒドロキソ白金酸のアミン溶液である。ここで、十分激しい攪拌とは、反応液の液面が激しく波打つ状態の攪拌であり、攪拌子又は攪拌羽根の回転速度は通常１００ｒｐｍ〜４００ｒｐｍ、好ましくは２５０ｒｐｍ〜３５０ｒｐｍである。 The hexahydroxoplatinic acid nanocolloid is prepared by preparing an amine solution of hexahydroxoplatinic acid or a dilute solution of sodium or potassium salt of hexahydroxoplatinic acid and adding a dilute solution of the neutralizing agent dropwise or while stirring vigorously. Obtained by spray addition. An amine solution of hexahydroxoplatinic acid is preferable. Alternatively, it can be obtained by adding dropwise or spraying a dilute solution of hexahydroxoplatinic acid or a dilute solution of sodium salt or potassium salt of hexahydroxoplatinate to a dilute solution of the neutralizing agent sufficiently vigorously. An amine solution of hexahydroxoplatinic acid is preferable. Here, sufficiently vigorous stirring is stirring in a state where the liquid level of the reaction solution is undulating, and the rotational speed of the stirring bar or stirring blade is usually 100 rpm to 400 rpm, preferably 250 rpm to 350 rpm.
中和剤としては各種の酸が用いられるが、好適には、酢酸やプロピオン酸等のカルボン酸又は硝酸である。また、アミンとしては各種のアミンが用いられるが、好適には２エタノールアミンである。溶媒としては水、メタノール、エタノール等の各種溶媒が用いられるが、好適には水である。 Various acids are used as the neutralizing agent, and preferably a carboxylic acid such as acetic acid or propionic acid, or nitric acid. Various amines are used as the amine, and 2-ethanolamine is preferred. As the solvent, various solvents such as water, methanol and ethanol are used, and water is preferred.
滴下の条件は、１５℃から３０℃程度の室温で、滴下時間は通常１０分から３時間程度、好ましくは２０分〜１時間であり、ゆっくりと一滴ずつ滴下する。滴下の間隔は、液滴の径にもよるが通常１〜６０秒おき、好適には５〜２０秒おきである。滴下の代わりに、相当する流速で、噴霧ノズルから噴霧させて添加しても良い。攪拌される反応液中の基質の濃度は、通常０．１ｍｍｏｌ／Ｌ〜５０ｍｍｏｌ／Ｌ、好ましくは１ｍｍｏｌ／Ｌ〜２０ｍｍｏｌ／Ｌであり、滴下される他方の基質の濃度は、通常１ｍｍｏｌ／Ｌ〜１ｍｏｌ／Ｌ、好ましくは１０ｍｍｏｌ／Ｌ〜２００ｍｍｏｌ／Ｌである。用いる中和剤の量は、滴下終了時のｐＨが略中性、即ち、通常５．３〜８．０、好ましくは５．７〜７．８となるように選択される。 The conditions for dropping are room temperature of about 15 ° C. to 30 ° C., and the dropping time is usually about 10 minutes to 3 hours, preferably 20 minutes to 1 hour. The interval of dropping is usually 1 to 60 seconds, preferably 5 to 20 seconds, depending on the diameter of the droplets. Instead of dropping, it may be added by spraying from a spray nozzle at a corresponding flow rate. The concentration of the substrate in the reaction solution to be stirred is usually 0.1 mmol / L to 50 mmol / L, preferably 1 mmol / L to 20 mmol / L, and the concentration of the other substrate added dropwise is usually 1 mmol / L to 1 mol / L, preferably 10 mmol / L to 200 mmol / L. The amount of the neutralizing agent to be used is selected so that the pH at the end of dropping is substantially neutral, that is, usually 5.3 to 8.0, preferably 5.7 to 7.8.
得られるヘキサヒドロキソ白金酸ナノコロイドの一次粒子径は、通常０．５ｎｍ〜３．０ｎｍであり、好ましくは０．５ｎｍ〜２．０ｎｍである。二次粒子径は通常５０〜２００ｎｍ、好ましくは５０〜１００ｎｍである。なお、本明細書においては、コロイドの一次粒子径は、高分解能透過電子顕微鏡（ＴＥＭ）又は電界放出型走査電子顕微鏡（ＦＥ‐ＳＥＭ）による形態観察で求められる個数平均粒子径を指す。粉末法Ｘ回折で求められる結晶子径は、通常、これらの電子顕微鏡で観察される一次粒子径とほぼ同等である。またコロイドの二次粒子の粒度分布は、動的光散乱（ＤＰＳ）法で測定され、その平均粒子径及び多分散度係数としては、光子相関法で求められるＺ‐Ａｖｅｒａｇｅ及びＰＤＩを用いる。 The primary particle diameter of the resulting hexahydroxoplatinic acid nanocolloid is usually 0.5 nm to 3.0 nm, preferably 0.5 nm to 2.0 nm. The secondary particle size is usually 50 to 200 nm, preferably 50 to 100 nm. In the present specification, the primary particle diameter of the colloid refers to the number average particle diameter determined by morphological observation with a high-resolution transmission electron microscope (TEM) or a field emission scanning electron microscope (FE-SEM). The crystallite size determined by powder method X diffraction is usually almost the same as the primary particle size observed with these electron microscopes. In addition, the particle size distribution of the secondary particles of the colloid is measured by a dynamic light scattering (DPS) method, and Z-Average and PDI obtained by the photon correlation method are used as the average particle size and polydispersity coefficient.
（還元工程）
本工程では、ナノコロイド生成工程で得られたヘキサヒドロキソ白金酸ナノコロイドに還元剤を添加してＩＶ価白金を０価へ還元する。
(Reduction process)
In this step, a reducing agent is added to the hexahydroxoplatinic acid nanocolloid obtained in the nanocolloid production step to reduce IV valent platinum to zero valence.
還元剤としては、ホルマリン、蟻酸、抱水ヒドラジン、クエン酸、アスコルビン酸等の従来から知られた液相還元剤や、コロイド中への水素含有ガスバブリングが用いられるが、好適には蟻酸である。還元反応の条件は、ナノコロイド生成工程で得られたヘキサヒドロキソ白金酸ナノコロイドが０価に還元され、且つ、生成した白金ナノコロイドが凝集しない条件を、用いる還元剤の種類と濃度に応じて選択する。還元剤が液相の場合は、還元剤溶液中の還元剤の濃度は、通常１０ｍｍｏｌ／Ｌ〜１０ｍｏｌ／Ｌ、好ましくは１００ｍｍｏｌ／Ｌ〜１．０ｍｏｌ／Ｌである。液相還元剤を添加する際の雰囲気には限定されないが、大気開放系や、酸素含有ガス雰囲気下、例えば合成空気の流通下で行うことが好ましい。窒素やアルゴン等不活性ガス雰囲気下で液相還元を行うと比表面積が抑制されることがある。還元剤が水素含有ガスの場合は、水素濃度は通常１％〜１００％、好ましくは１０％〜５０％であり、残部は窒素、アルゴン又はヘリウムであり、好ましくは窒素である。 As the reducing agent, conventionally known liquid phase reducing agents such as formalin, formic acid, hydrazine hydrate, citric acid, ascorbic acid and hydrogen-containing gas bubbling into the colloid are used, but formic acid is preferred. . The conditions for the reduction reaction are the conditions under which the hexahydroxoplatinic acid nanocolloid obtained in the nanocolloid production step is reduced to zero and the produced platinum nanocolloid does not aggregate depending on the type and concentration of the reducing agent used. select. When the reducing agent is in a liquid phase, the concentration of the reducing agent in the reducing agent solution is usually 10 mmol / L to 10 mol / L, preferably 100 mmol / L to 1.0 mol / L. Although it is not limited to the atmosphere at the time of adding a liquid phase reducing agent, it is preferable to carry out by the open air system or oxygen-containing gas atmosphere, for example, the circulation of synthetic air. When liquid phase reduction is performed in an inert gas atmosphere such as nitrogen or argon, the specific surface area may be suppressed. When the reducing agent is a hydrogen-containing gas, the hydrogen concentration is usually 1% to 100%, preferably 10% to 50%, and the balance is nitrogen, argon or helium, preferably nitrogen.
還元工程の反応温度は通常４℃〜１００℃、好ましくは２０℃〜９８℃である。添加する還元剤の量はＩＶ価の白金を０価へ還元するのに必要な化学量論量に対し通常０．５〜２．０当量であり、好ましくは０．７〜１．５当量である。還元剤の添加に要する時間は通常５分〜４時間、好ましくは２０分〜２時間であり、滴下する場合は一滴ずつゆっくり滴下することが好ましい。滴下の間隔は液滴の径にも依るが通常１〜６０秒おき、好適には５〜２０秒おきである。滴下する代わりに噴霧ノズルを用いて、相当する添加速度で噴霧添加しても良い。添加後も一定温度で攪拌を保持する還元反応保持時間は、通常５分〜２４時間、好ましくは２０分〜８時間である。還元反応の進行度は、最初のヘキサヒドロキソ白金酸のナノコロイドの乳白色が、次第にグレー化し、最後は真黒なブラックへと変化する色調変化で追跡できる。 The reaction temperature in the reduction step is usually 4 ° C to 100 ° C, preferably 20 ° C to 98 ° C. The amount of the reducing agent to be added is usually 0.5 to 2.0 equivalents, preferably 0.7 to 1.5 equivalents, relative to the stoichiometric amount necessary to reduce IV valent platinum to zero valence. is there. The time required for the addition of the reducing agent is usually 5 minutes to 4 hours, preferably 20 minutes to 2 hours. The interval of dropping depends on the diameter of the droplet, but is usually every 1 to 60 seconds, preferably every 5 to 20 seconds. Instead of dripping, spray addition may be performed at a corresponding addition rate using a spray nozzle. The reduction reaction holding time for holding stirring at a constant temperature after the addition is usually 5 minutes to 24 hours, preferably 20 minutes to 8 hours. The degree of progress of the reduction reaction can be followed by a change in color tone, in which the milky white color of the first colloidal hexahydroxoplatinic acid gradually turns gray and finally turns to black black.
（洗浄工程）
本工程では、還元工程で得られた白金含有コロイドをろ過し、純水洗浄する。ろ過は、ナノ粒子のろ過漏れを防ぐために最大通過粒子サイズが０．１〜０．２μｍのメンブレンフィルターを用いる。ろ過後ケークは電導度１μｓ／ｃｍ以下、好ましくは０．８μｓ／ｃｍ以下の、脱イオン水又は超純水、好ましくは同温水にて、濾液の電導度が２．０μｓ／ｃｍ以下、好ましくは１．０μｓ／ｃｍ以下となるまで洗浄する。
(Washing process)
In this step, the platinum-containing colloid obtained in the reduction step is filtered and washed with pure water. Filtration uses a membrane filter having a maximum passing particle size of 0.1 to 0.2 μm in order to prevent filtration leakage of the nanoparticles. The post-filtration cake has an electrical conductivity of 1 μs / cm or less, preferably 0.8 μs / cm or less, in deionized water or ultrapure water, preferably the same temperature water, and the filtrate has a conductivity of 2.0 μs / cm or less, preferably Wash until 1.0 μs / cm or less.
（乾燥工程）
本工程では、洗浄した白金含有コロイドを乾燥する。具体的には、洗浄後のろ過ケークを空気中で吸引風乾させ、水分率４５％以下まで、好ましくは水分率４２％〜３５％まで、乾燥させる。水分率４５％以下まで風乾すれば、濾紙から掻き取ったり薬匙で秤量したり粉末として取り扱うことが可能である。水分率が４５％を超えて高いと粘稠な泥状物となり、取り扱いが困難となる可能性がある。本発明の高比表面積の白金ブラックは活性が高く、乾燥による発火の危険性を避けるには、このようなウェットケークで保存することが好ましい。その場合は保存容器を密閉し水分の揮散による水分率の経時変化を防ぐ必要がある。他方、風乾後の固体は、更に乾燥機やデシケーター中で水分率４％程度まで乾燥されてもよい。このような乾燥状態では、水分率の経時変化を殆ど無視でき、保存・取り扱いが容易であるが、乾燥条件の管理には注意を要する。乾燥の雰囲気には依存しないが、空気中の乾燥が好ましい。乾燥時の温度は、白金粒子の凝集を防ぐために、できるだけ低温で行う。好ましくは８０℃以下、更に好ましくは６０℃以下である。安全性の観点から、最終の水分率は、本発明の白金ブラックの全細孔容積相当の水分率未満にしないことが好ましい。例えば、全細孔容積０．０４ｃｍ３／ｇの白金ブラックの好ましい水分率の下限は４質量％である。これ以上に乾燥させると取り扱い中に発火する可能性がある。
(Drying process)
In this step, the washed platinum-containing colloid is dried. Specifically, the filter cake after washing is sucked and air-dried in the air, and dried to a moisture content of 45% or less, preferably 42 to 35%. If it is air-dried to a moisture content of 45% or less, it can be scraped off from filter paper, weighed with a medicine basket, or handled as a powder. If the moisture content is higher than 45%, it becomes a viscous mud and may be difficult to handle. The high specific surface area platinum black of the present invention has high activity, and it is preferable to store it in such a wet cake in order to avoid the risk of ignition due to drying. In that case, it is necessary to seal the storage container and prevent the moisture content from changing over time due to the evaporation of moisture. On the other hand, the solid after air drying may be further dried to a moisture content of about 4% in a dryer or desiccator. In such a dry state, a change in moisture content with time can be almost ignored, and storage and handling are easy, but care must be taken in managing the drying conditions. Although it does not depend on the drying atmosphere, drying in air is preferable. The drying temperature is as low as possible in order to prevent aggregation of platinum particles. Preferably it is 80 degrees C or less, More preferably, it is 60 degrees C or less. From the viewpoint of safety, the final moisture content is preferably not less than the moisture content equivalent to the total pore volume of the platinum black of the present invention. For example, the lower limit of the preferable moisture content of platinum black having a total pore volume of 0.04 cm 3 / g is 4% by mass. Drying more than this may cause fire during handling.
（酸素処理工程）
本実施形態に係る白金ブラック粉末の製造方法では、還元工程の後に、白金含有コロイドに空気乃至酸素ガスを吹き込む酸素処理工程をさらに有することが好ましい（第二形態）。本工程は、より好ましい製造方法とするための付加的工程であり、還元工程で得られる白金含有コロイドに空気乃至酸素ガスを吹き込み、白金ナノ粒子を高分散化処理する。還元工程で得られる白金ナノ粒子の分散液を攪拌しながら、液中に空気又は酸素ガスを、例えば流速１００ｍＬ／ｍｉｎ〜１０Ｌ／ｍｉｎ、好ましくは流速２００ｍＬ／ｍｉｎ〜２Ｌ／ｍｉｎで、例えば１０分〜４時間、好ましくは２０分〜２時間、吹き込む。その後、洗浄工程、乾燥工程へと進む。
(Oxygen treatment process)
In the method for producing platinum black powder according to this embodiment, it is preferable to further include an oxygen treatment step of blowing air or oxygen gas into the platinum-containing colloid after the reduction step (second embodiment). This step is an additional step for obtaining a more preferable production method, and air or oxygen gas is blown into the platinum-containing colloid obtained in the reduction step to highly disperse the platinum nanoparticles. While stirring the dispersion of platinum nanoparticles obtained in the reduction step, air or oxygen gas is introduced into the liquid, for example, at a flow rate of 100 mL / min to 10 L / min, preferably at a flow rate of 200 mL / min to 2 L / min, for example, 10 minutes. Blow for ~ 4 hours, preferably 20 minutes to 2 hours. Then, it progresses to a washing process and a drying process.
空気又は酸素ガスの吹き込みは、例えば液温４℃〜１００℃、好適には液温１５℃〜６０℃、更に好適には２０℃〜４０℃で行われる。酸素処理工程において、空気若しくは酸素ガスの代わりに窒素やアルゴンガス等の不活性ガスを用いると、本実施形態に係る高い比表面積の白金ブラックは得られ難い。水素ガスを吹き込むと、比表面積は却って大幅に減少することがある。白金含有コロイドの空気又は酸素ガスとの接触による白金ブラックの比表面積増大効果は、もともと、洗浄・風乾後の水分率４０％程度のウェットケークの白金ブラックの比表面積が、１ヶ月から半年の空気中保存後、驚くべきことに１割〜２割も増大していることを本発明者等が見出したことに由来する。このような比表面積の増大は、乾燥状態で保存された白金ブラックや、ウェットケークでも不活性ガス置換状態で保存された白金ブラックには見られなかった。このような水分と酸素とが共存する条件で、白金ブラックの比表面積が増大する理由は目下不明ではあるが、酸素処理が白金ナノ粒子の表面に酸素含有種を吸着させることによって白金ナノ粒子の分散性の向上に寄与しているものと推察される。 The blowing of air or oxygen gas is performed, for example, at a liquid temperature of 4 ° C to 100 ° C, preferably at a liquid temperature of 15 ° C to 60 ° C, and more preferably at 20 ° C to 40 ° C. If an inert gas such as nitrogen or argon gas is used instead of air or oxygen gas in the oxygen treatment process, it is difficult to obtain platinum black having a high specific surface area according to this embodiment. When hydrogen gas is blown in, the specific surface area may be significantly reduced. The effect of increasing the specific surface area of platinum black by the contact of platinum-containing colloids with air or oxygen gas is that the specific surface area of wet black platinum black with a moisture content of about 40% after cleaning and air-drying is from 1 month to 6 months. This is because the present inventors have found that surprisingly 10 to 20% increase after storage in the middle. Such an increase in specific surface area was not observed in platinum black stored in a dry state or platinum black stored in an inert gas substitution state even in a wet cake. The reason why the specific surface area of platinum black increases under such conditions in which moisture and oxygen coexist is currently unknown, but oxygen treatment causes the adsorption of oxygen-containing species on the surface of the platinum nanoparticles, thereby allowing the platinum nanoparticles to adsorb. It is assumed that it contributes to the improvement of dispersibility.
上記の本実施形態に係る白金ブラック粉末の製造方法（第一形態）によれば、８０ｍ２／ｇ以上のＢＥＴ比表面積を有する白金ブラック粉末が得られる。更に酸素処理工程を付加的に加えた製造方法（第二形態）によれば、９０ｍ２／ｇ以上のＢＥＴ比表面積を有する白金ブラック粉末が得られ易い。中間体ヘキサヒドロキソ白金酸ナノコロイドの１次粒子径０．５ｎｍ〜２．０ｎｍを、できる限り成長させずに還元して白金ブラックに転換することによって、本発明の製造方法の白金ブラックの比表面積は１００ｍ２／ｇ以上、例えば、１４０ｍ２／ｇ、更には１９０ｍ２／ｇ程度まで達成できる。また、本発明の製法に依れば全細孔容積が０．０３８ｃｍ３／ｇ以上である白金ブラック粉末が得られる。好ましくは全細孔容積が０．０４０ｃｍ３／ｇ以上である。また、元素分析による酸素の乾燥質量換算の含有率が３．５質量％以上７．０質量％以下であることが好ましい。更に好ましくは、４．０質量％以上６．５質量％以下である。ここで、白金ブラック中の元素Ａの乾燥質量換算の含有率とは水分を全く含まない白金ブラックの質量を分母とする含有率であり、（数９）より求める。
(数９)
乾燥質量換算の含有率（％）＝（白金ブラック中の元素Ａの質量／水分を全く含まないとしたときの白金ブラックの質量）×１００
According to the platinum black powder manufacturing method (first embodiment) according to the present embodiment, a platinum black powder having a BET specific surface area of 80 m 2 / g or more is obtained. Furthermore, according to the production method (second embodiment) in which an oxygen treatment step is additionally added, a platinum black powder having a BET specific surface area of 90 m 2 / g or more is easily obtained. The specific surface area of platinum black in the production method of the present invention is reduced by reducing the primary particle size of the intermediate hexahydroxoplatinate nanocolloid from 0.5 nm to 2.0 nm without growing as much as possible to platinum black. Can be achieved to 100 m 2 / g or more, for example, 140 m 2 / g, and further up to about 190 m 2 / g. Moreover, according to the manufacturing method of this invention, the platinum black powder whose total pore volume is 0.038 cm < 3 > / g or more is obtained. Preferably, the total pore volume is 0.040 cm 3 / g or more. Moreover, it is preferable that the content rate of the dry mass conversion of oxygen by elemental analysis is 3.5 mass% or more and 7.0 mass% or less. More preferably, it is 4.0 mass% or more and 6.5 mass% or less. Here, the content in terms of dry mass of element A in platinum black is a content with the mass of platinum black not containing any water as a denominator, and is obtained from (Equation 9).
(Equation 9)
Content (%) in terms of dry mass = (mass of element A in platinum black / mass of platinum black when no moisture is contained) × 100
白金ブラックの水分率は、１０−２ｋＰａ以下の真空度にて６０℃、２時間の真空乾燥処理の前後の質量変化から算出される。なお、白金ブラック粉末に含まれる酸素は、原子状酸素、吸着酸素分子、過酸化物、酸素ラジカル、窒素酸化物等色々な形態をとりえ、前記組成は酸素の元素分析値である。酸素含有率は酸素・窒素分析装置、例えばＬＥＣＯ・ジャパン製、ＴＣ−６００等で分析される。更に、得られた白金ブラック粉末は、粉末法Ｘ線回折で検出される白金含有種が立方晶白金のみであり、そのＰｔ（２２０）結晶子サイズが３．０ｎｍ以下であるような一次粒子径の小さい白金ブラック粉末である。 The moisture content of platinum black is calculated from the mass change before and after the vacuum drying treatment at 60 ° C. for 2 hours at a vacuum degree of 10 −2 kPa or less. The oxygen contained in the platinum black powder can take various forms such as atomic oxygen, adsorbed oxygen molecules, peroxides, oxygen radicals, nitrogen oxides, and the composition is an elemental analysis value of oxygen. The oxygen content is analyzed by an oxygen / nitrogen analyzer such as TC-600 manufactured by LECO Japan. Further, the obtained platinum black powder has a primary particle size such that the platinum-containing species detected by powder X-ray diffraction is only cubic platinum, and the Pt (220) crystallite size is 3.0 nm or less. Is a small platinum black powder.
本実施形態で得られた白金ブラック粉末は、不純物として含有される塩素及びアルカリ金属の乾燥質量換算の含有量が、いずれも５００ｐｐｍ以下であることが好ましい。塩素及びアルカリ金属はＩＣＰ（高周波誘導結合プラズマ）発光分析装置で分析される。不純物として含有される塩素及びアルカリ金属を低下させるためには、塩素及びアルカリ金属の含有率がそれぞれ５００ｐｐｍ以下と低いヘキサヒドロキソ白金酸の結晶を出発原料としてそのアミン溶液を用いることが好ましい。塩素及びアルカリ金属の含有率がそれぞれ５００ｐｐｍ以下のヘキサヒドロキソ白金酸の結晶を得るには、例えば、特許文献３の実施例１の方法に従って製造し、不純物の含有率を抑制するために洗浄工程で、文献記載の方法よりも一層入念に、例えばろ過後ケークを電導度０．８μｓ／ｃｍ以下の純温水で濾液の電導度が１．０μｓ／ｃｍ以下となるまで、洗浄することによって得られる。このようなヘキサヒドロキソ白金酸のアミン溶液を出発原料とし、本発明の製造方法に従って、中和剤や還元剤としてハロゲン化物やアルカリ金属化合物を一切使用しなければ、不純物として含有される塩素及びアルカリ金属の乾燥質量換算の含有量が、いずれも５００ｐｐｍ以下の白金ブラックが得られる。塩素イオンやアルカリ金属イオンは、白金ブラックを触媒として使用する際に厄介な被毒物質となることがあり含有率はできるだけ低いことが望ましい。 The platinum black powder obtained in this embodiment preferably has a dry mass equivalent content of chlorine and alkali metals contained as impurities of 500 ppm or less. Chlorine and alkali metals are analyzed with an ICP (High Frequency Inductively Coupled Plasma) emission spectrometer. In order to reduce chlorine and alkali metal contained as impurities, it is preferable to use an amine solution starting from crystals of hexahydroxoplatinic acid having a chlorine and alkali metal content as low as 500 ppm or less, respectively. In order to obtain crystals of hexahydroxoplatinic acid having a chlorine and alkali metal content of 500 ppm or less, for example, it is produced according to the method of Example 1 of Patent Document 3, and the washing step is performed to suppress the impurity content. More carefully than the methods described in the literature, for example, the post-filter cake is obtained by washing with pure warm water having an electric conductivity of 0.8 μs / cm or less until the filtrate has an electric conductivity of 1.0 μs / cm or less. If such an amine solution of hexahydroxoplatinic acid is used as a starting material and no halide or alkali metal compound is used as a neutralizing agent or reducing agent in accordance with the production method of the present invention, chlorine and alkali contained as impurities A platinum black having a metal dry mass equivalent content of 500 ppm or less is obtained. Chlorine ions and alkali metal ions may become troublesome poisonous substances when using platinum black as a catalyst, and the content is desirably as low as possible.
次に本実施形態に係る白金ブラックコロイドの製造法について説明する。本実施形態に係る白金ブラックコロイドの製造方法（第一形態）は、液相中にヘキサヒドロキソ白金酸のナノコロイドを生成させるナノコロイド生成工程と、前記ナノコロイドに還元剤を添加して前記ナノコロイドを還元し、白金含有コロイドを形成する還元工程と、前記白金含有コロイドをろ過し純水洗浄する洗浄工程と、洗浄した白金含有コロイドを溶媒に分散する分散工程と、を有する。ナノコロイド生成工程、還元工程及び洗浄工程については、本実施形態に係る白金ブラック粉末の製造法と同じである。洗浄工程後の白金ブラックのウェットケークを、適当な溶媒に入れて、超音波や遊星ボールミル等で分散処理することによって、粒度分布測定において、粒子径０．１ｎｍ〜１００００ｎｍの領域に単一ピークの粒度分布曲線を有し、平均粒子径が２５０ｎｍ以下で且つ多分散度指数が０．１５以下の、シャープな粒度分布を有する白金ブラックのコロイドが得られる。分散溶媒としては、通常、水、メタノール、エタノール、ｎ−プロパノール、イソプロパノール或いはそれらの混合物からなるプロトン性極性溶媒が用いられ、好適には水である。分散処理の時間は通常、１分間〜２時間、好適には５分間〜１時間である。分散後の濃度は、例えばドライ換算白金ブラック０．０１ｇ／Ｌ〜１０．０ｇ／Ｌであり、好ましくは０．１０ｇ／Ｌ〜２．０ｇ／Ｌである。このコロイドのゼータ電位を測定すると、マイナス４０ｍＶ以下、好ましくはマイナス４５ｍＶ以下である。一般に、コロイドのゼータ電位は絶対値が４０ｍＶ以上で大きいほど、コロイドとしての安定性が高いとされている。本発明の白金ブラックのコロイドは、空気中室温で少なくとも数日間、好適には例えば１ヶ月に亘って、凝集を生じることなく安定である。 Next, a method for producing a platinum black colloid according to this embodiment will be described. The method for producing a platinum black colloid according to the present embodiment (first embodiment) includes a nanocolloid production step of producing a hexahydroxoplatinic acid nanocolloid in a liquid phase, and a reducing agent added to the nanocolloid to form the nanocolloid. A reduction step of reducing the colloid to form a platinum-containing colloid, a washing step of filtering the platinum-containing colloid and washing with pure water, and a dispersion step of dispersing the washed platinum-containing colloid in a solvent. The nanocolloid generation step, reduction step, and washing step are the same as in the method for producing platinum black powder according to this embodiment. The platinum black wet cake after the washing step is placed in an appropriate solvent and dispersed with an ultrasonic wave or a planetary ball mill, etc., and in the particle size distribution measurement, a single peak is observed in the region having a particle diameter of 0.1 nm to 10000 nm. A platinum black colloid having a particle size distribution curve, an average particle size of 250 nm or less, and a polydispersity index of 0.15 or less and having a sharp particle size distribution is obtained. As the dispersion solvent, a protic polar solvent composed of water, methanol, ethanol, n-propanol, isopropanol or a mixture thereof is usually used, and preferably water. The dispersion treatment time is usually 1 minute to 2 hours, preferably 5 minutes to 1 hour. The density | concentration after dispersion | distribution is 0.01 g / L-10.0 g / L of dry conversion platinum black, for example, Preferably it is 0.10 g / L-2.0 g / L. When the zeta potential of this colloid is measured, it is minus 40 mV or less, preferably minus 45 mV or less. In general, it is said that the higher the absolute value of the colloid zeta potential is 40 mV or higher, the higher the stability as a colloid. The colloid of platinum black of the present invention is stable without agglomeration at room temperature in air for at least several days, preferably for a month, for example.
白金ブラックコロイドの他の製造法として、本実施形態に係る白金ブラック粉末を得た後、白金ブラック粉末を、適当な溶媒に入れて、超音波や遊星ボールミル等で分散処理することによって、コロイド化しても良い。この場合においても、粒度分布測定において、粒子径０．１ｎｍ〜１００００ｎｍの領域に単一ピークの粒度分布曲線を有し、平均粒子径が２５０ｎｍ以下で且つ多分散度指数が０．１５以下の、シャープな粒度分布を有する白金ブラックのコロイドが得られる。分散溶媒の種類、分散処理の時間、及び分散後の濃度は、前段落の記載内容と同じである。 As another method for producing a platinum black colloid, after obtaining the platinum black powder according to the present embodiment, the platinum black powder is put into an appropriate solvent and dispersed by an ultrasonic wave or a planetary ball mill, thereby colloidalizing. May be. Even in this case, in the particle size distribution measurement, it has a single peak particle size distribution curve in the region of the particle size of 0.1 nm to 10000 nm, the average particle size is 250 nm or less and the polydispersity index is 0.15 or less, A colloid of platinum black having a sharp particle size distribution is obtained. The type of the dispersion solvent, the dispersion treatment time, and the concentration after dispersion are the same as those described in the previous paragraph.
前記した本実施形態に係る白金ブラックコロイドの製造法及び白金ブラックコロイドの他の製造法において、還元工程の後に、白金含有コロイドに空気乃至酸素ガスを吹き込む酸素処理工程をさらに有することが好ましい（第二形態）。この処理によって白金ブラックのコロイド粒子の分散の程度がより高くなる。本発明の白金ブラックのコロイドには、溶媒と白金ブラックの他に、パーフルオロスルフォン酸系の高分子電解質のアイオノマー、例えば商標名ナフィオン（デユポン社製）や商標名フレミオン（旭硝子製）等、を添加してもよい。アイオノマーは、白金ブラックのコロイドを調製した後にこれに添加してもよいし、白金ブラックとアイオノマーを溶媒に添加して同時に分散処理してコロイド化してもよい。アイオノマーの添加比率は、白金ブラック１に対して、例えば質量比で１：０．０１〜１：１０、好ましくは１：０．０５〜１：２の範囲である。このようなアイオノマー添加白金ブラックコロイドは電気化学的電極形成用触媒インクとして用いられる。 In the method for producing platinum black colloid and the other method for producing platinum black colloid according to the above-described embodiment, it is preferable that the method further includes an oxygen treatment step of blowing air or oxygen gas into the platinum-containing colloid after the reduction step. Two forms). This treatment increases the degree of dispersion of the platinum black colloidal particles. The colloid of platinum black of the present invention includes, in addition to the solvent and platinum black, an ionomer of a perfluorosulfonic acid-based polymer electrolyte, for example, trade name Nafion (manufactured by Deyupon), trade name Flemion (manufactured by Asahi Glass) It may be added. The ionomer may be added to a platinum black colloid after it has been prepared, or platinum black and ionomer may be added to a solvent and simultaneously dispersed to be colloidalized. The addition ratio of the ionomer is, for example, in a mass ratio of 1: 0.01 to 1:10, preferably 1: 0.05 to 1: 2 with respect to platinum black 1. Such an ionomer-added platinum black colloid is used as a catalyst ink for electrochemical electrode formation.
以下、実施例を示しながら本発明についてさらに詳細に説明するが、本発明は実施例に限定して解釈されない。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not construed as being limited to the examples.
実施例で用いる純水は全てイオン交換を２回行ったｐＨ６．０〜７．０、電気伝導度０．８μｓ／ｃｍ以下の超純水を用いた。反応に使用するフラスコやテフロン（登録商標）攪拌羽根は使用前に王水で洗浄し、その後純水で十分濯ぎ洗いして用いた。 The pure water used in the examples was ultrapure water having a pH of 6.0 to 7.0 and an electric conductivity of 0.8 μs / cm or less, in which ion exchange was performed twice. The flask and Teflon (registered trademark) stirring blade used in the reaction were washed with aqua regia before use and then rinsed thoroughly with pure water before use.
＜参考例１＞ヘキサヒドロキソ白金酸２‐アミノエタノール水溶液の製造
ヘキサヒドロキソ白金酸は、特許文献３の実施例１の方法に従って次のとおり製造した。但し、ヘキサヒドロキソ白金酸の結晶は、不純物の含有率を抑制するために上記文献記載の方法よりも一層入念に洗浄した。５ＬナスフラスコにＮａＯＨ７５．２ｇを入れ純水１．８Ｌを添加して溶解させ、加熱し沸騰させた。これに白金２００ｇ／Ｌを含む塩化白金酸（Ｈ２ＰｔＣｌ６）水溶液２００．８ｇと純水７０ｍｌを加え、１６時間沸騰状態を保持した。室温まで放冷後、攪拌しながら５０ｖｏｌ％の酢酸水溶液をゆっくり滴下しｐＨを５．０に調整した。生じた沈殿をろ過し、純温水で濾液の電導度が１．０μｓ／ｃｍ以下となるまで念入りに洗浄した。室温デシケーター中で乾燥し、ヘキサヒドロキソ白金酸（Ｈ２Ｐｔ（ＯＨ）６）の白色結晶を得た。この結晶を塩酸で溶解した溶液からアルカリ金属を、また硫酸水溶液に溶解後アルミニウム還元で白金を除去した後の濾液から塩素を、それぞれＩＣＰ発光分析装置（理学電機製、ＣＩＲＯＳ１２０）によって分析した。このヘキサヒドロキソ白金酸中の塩素及びＮａ含有率は白金に対して各々３００ｐｐｍと４５０ｐｐｍであった。Ｎａ以外のアルカリ金属の濃度はＩＣＰ分析の検出限界以下であった。ヘキサヒドロキソ白金酸２‐アミノエタノール水溶液は特許文献７の実施例１の記載に従い次のように製造した。白金４０ｇ相当のヘキサヒドロキソ白金酸に純水３４８ｍｌを加え、白金に対し２．５倍当量の２‐アミノエタノールを加え、室温にて２時間撹拌した。撹拌終了後、更に２‐アミノエタノール２．５倍当量を加え２時間攪拌保持して、淡黄色のヘキサヒドロキソ白金酸２‐アミノエタノール水溶液を得た。白金の濃度は８．５質量％、ｐＨ１１であった。
Reference Example 1 Production of Aqueous Hexahydroxoplatinic Acid 2-Aminoethanol Hexahydroxoplatinic acid was produced as follows according to the method of Example 1 of Patent Document 3. However, the crystals of hexahydroxoplatinic acid were washed more carefully than the method described in the above document in order to suppress the impurity content. To a 5 L eggplant flask, 75.2 g of NaOH was added and dissolved by adding 1.8 L of pure water, followed by heating to boiling. 200.8 g of chloroplatinic acid (H 2 PtCl 6 ) aqueous solution containing 200 g / L of platinum and 70 ml of pure water were added thereto, and the boiling state was maintained for 16 hours. After cooling to room temperature, a 50 vol% aqueous acetic acid solution was slowly added dropwise with stirring to adjust the pH to 5.0. The resulting precipitate was filtered and washed thoroughly with pure warm water until the conductivity of the filtrate was 1.0 μs / cm or less. Drying in a room temperature desiccator gave white crystals of hexahydroxoplatinic acid (H 2 Pt (OH) 6 ). An alkali metal was analyzed from a solution in which the crystals were dissolved in hydrochloric acid, and chlorine was analyzed from an filtrate obtained by dissolving platinum in an aqueous sulfuric acid solution and then removing platinum by aluminum reduction, using an ICP emission spectrometer (CIROS 120, manufactured by Rigaku Corporation). The chlorine and Na contents in the hexahydroxoplatinic acid were 300 ppm and 450 ppm, respectively, with respect to platinum. The concentration of alkali metals other than Na was below the detection limit of ICP analysis. A hexahydroxoplatinic acid 2-aminoethanol aqueous solution was prepared as described in Example 1 of Patent Document 7 as follows. 348 ml of pure water was added to hexahydroxoplatinic acid equivalent to 40 g of platinum, 2.5-fold equivalent of 2-aminoethanol was added to platinum, and the mixture was stirred at room temperature for 2 hours. After completion of stirring, 2.5 equivalents of 2-aminoethanol was further added and the mixture was stirred and maintained for 2 hours to obtain a pale yellow hexahydroxoplatinic acid 2-aminoethanol aqueous solution. The concentration of platinum was 8.5% by mass and pH 11.
＜実施例１＞高比表面積白金ブラックの製造（酸素処理工程を経る製法）
（ナノコロイド生成工程）
３Ｌ四つ口フラスコに純水１．２Ｌを入れ、これに氷酢酸１．５０ｇの２０ｍｌ純水液溶を添加した。テフロン（登録商標）羽根付きテフロン（登録商標）攪拌棒をモーターに接続し液温２５℃、３２０ｒｐｍで回転し十分攪拌した。フラスコ内部を合成空気（ゼロエアー）でパージした。白金１．５０ｇを含むヘキサヒドロキソ白金酸２‐アミノエタノール水溶液（Ｐｔ濃度８．５質量％）１７．６５ｇを、純水１５ｍｌに希釈し、これを滴下ロートから４０分かけてゆっくり滴下した。生成した薄い乳白色の半透明なコロイドの５ｍｌをサンプリングし、電界放出型走査電子顕微鏡ＦＥ‐ＳＥＭ（日本電子製、ＪＳＭ‐７６００Ｆ）で１次粒子の粒子径を観察し、動的光散乱(ＤＰＳ）粒度分布計（マルバーン社製、ゼータサイザーナノ）でコロイド粒子径を測定した。ＦＥ‐ＳＥＭでは図１に示すように直径０．５〜１．５ｎｍ程度の微細な１次粒子が観察され、ＤＰＳ粒度分布計ではコロイド平均粒子径Ｚ‐Ａｖｅｒａｇｅ１１０ｎｍ、多分散度指数ＰＤＩ０．１１０が得られ、ヘキサヒドロキソ白金酸ナノコロイドの生成を確認した。
（還元工程）
上記ヘキサヒドロキソ白金酸ナノコロイドを、空気流通下攪拌しながらマントルヒータで加熱し４０分で９５℃へ昇温した。９５℃にて０．９２ｍｌの９８％蟻酸の２５ｍｌ純水溶液を滴下ロートから４０分間に亘って一定の滴下速度でゆっくり滴下した。滴下終了後も、液温９５℃で攪拌を４０分間保持した。滴下開始から３０分後にコロイドの色調はグレーに変わり、数分後に濃いブラックに変化した。色調がブラックに変化した後も液温９５℃で攪拌を約１０分間保持し、その後加熱を止め室温まで攪拌しながら冷却した。
（酸素処理工程）
液温を３０℃まで冷却した時点で、側管から合成空気を３００ｍＬ／ｍｉｎの流量で吹き込みながらコロイドを攪拌し、３０分間保持した。
（洗浄工程）
得られたブラックのスラリーを孔径２００ｎｍのメンブレンフィルターで吸引ろ過し、ろ過ケークを冷純水、次いで温純水で洗浄し、ろ液の電導度が２．０μｓ／ｃｍ以下となるまで十分洗浄した。
（乾燥工程）
洗浄工程の後、２時間吸引風乾し、得られたウェットケークを蒸発皿に広げ、空気中室温で水分率４質量％まで自然乾燥させ、白金ブラック粉末１．５０ｇを得た。
（物性測定）
この白金ブラックの０．２ｇをサンプリングし、ガラス製の比表面積測定管に入れ、室温で１時間真空排気後６０℃で２時間、１０−２ｋＰａ以下の真空度で真空排気して前処理後、比表面積測定装置（日本ベル、ＢＥＬＳＯＲＰ‐ｍｉｎｉＩＩ）にて比表面積測定を行った。その結果、９３ｍ２／ｇのＢＥＴ比表面積、０．０４３ｃｍ３／ｇの全細孔容積を得た。またＸ線回折装置（リガク製、ＲＩＮＴ２５００／ＰＣ）にて粉末法Ｘ線回折測定を行ったところ、ｆｃｃ白金に固有な回折パターンを示しメインーピーク（１１１）の回折角２θ が３８．８°、（２２０）回折ピークから結晶子径は２．０ｎｍと計算された。この白金ブラックを透過電子顕微鏡ＴＥＭ（日立製作所製、Ｈ‐８００）で観察すると、図２に示すように粒子径２．０〜３．０ｎｍの一次粒子からなる二次粒子径１８０ｎｍ〜２５０ｎｍ程度の凝集体が観察された。この白金ブラック中のドライ換算酸素含有率は、酸素・窒素分析装置（ＬＥＣＯ・ジャパン製、ＴＣ−６００）によって、５．６質量％と分析された。またＩＣＰ分析によれば塩素およびＮａのドライ換算含有率はそれぞれ２５０ｐｐｍ、２００ｐｐｍであった。Ｎａ以外のアルカリ金属の含有率はＩＣＰ分析の検出下限以下であった。
<Example 1> Production of high specific surface area platinum black (production method through oxygen treatment step)
(Nano colloid production process)
1.2 L of pure water was placed in a 3 L four-necked flask, and 1.50 g of glacial acetic acid in 20 ml of pure water was added thereto. A Teflon (registered trademark) stirring rod with a Teflon (registered trademark) blade was connected to a motor, and the mixture was sufficiently stirred by rotating at a liquid temperature of 25 ° C. and 320 rpm. The inside of the flask was purged with synthetic air (zero air). 17.65 g of a hexahydroxoplatinic acid 2-aminoethanol aqueous solution (Pt concentration 8.5% by mass) containing 1.50 g of platinum was diluted in 15 ml of pure water, and this was slowly dropped from a dropping funnel over 40 minutes. Sample 5ml of the thin milky white translucent colloid produced, observe the particle size of the primary particles with a field emission scanning electron microscope FE-SEM (JSM-7600F, JEOL), and perform dynamic light scattering (DPS ) Colloid particle size was measured with a particle size distribution meter (Zetasizer Nano, manufactured by Malvern). In FE-SEM, fine primary particles having a diameter of about 0.5 to 1.5 nm are observed as shown in FIG. 1, and in the DPS particle size distribution meter, colloid average particle diameter Z-Average 110 nm, polydispersity index PDI 0.110 is obtained. Obtained and confirmed the formation of hexahydroxoplatinic acid nanocolloids.
(Reduction process)
The hexahydroxoplatinic acid nanocolloid was heated with a mantle heater while stirring under air flow, and the temperature was raised to 95 ° C. in 40 minutes. At 95 ° C., 0.92 ml of 25% pure aqueous solution of 98% formic acid was slowly dropped from the dropping funnel at a constant dropping rate over 40 minutes. Even after completion of the dropping, stirring was maintained at a liquid temperature of 95 ° C. for 40 minutes. The color of the colloid changed to gray 30 minutes after the start of dropping, and changed to dark black several minutes later. After the color changed to black, stirring was maintained at a liquid temperature of 95 ° C. for about 10 minutes, and then the heating was stopped and the mixture was cooled to room temperature while stirring.
(Oxygen treatment process)
When the liquid temperature was cooled to 30 ° C., the colloid was stirred while blowing synthetic air from the side tube at a flow rate of 300 mL / min, and held for 30 minutes.
(Washing process)
The obtained black slurry was suction filtered with a membrane filter having a pore size of 200 nm, and the filter cake was washed with cold pure water and then with hot pure water, and sufficiently washed until the electric conductivity of the filtrate was 2.0 μs / cm or less.
(Drying process)
After the washing step, suction air drying was performed for 2 hours, and the obtained wet cake was spread on an evaporating dish and naturally dried to a moisture content of 4% by mass at room temperature in air to obtain 1.50 g of platinum black powder.
(Physical property measurement)
0.2 g of this platinum black was sampled, put into a glass specific surface area measuring tube, evacuated at room temperature for 1 hour, then evacuated at 60 ° C. for 2 hours and at a vacuum degree of 10 −2 kPa or less, and after pretreatment The specific surface area was measured with a specific surface area measuring apparatus (Nippon Bell, BELSORP-mini II). As a result, a BET specific surface area of 93 m 2 / g and a total pore volume of 0.043 cm 3 / g were obtained. Further, when powder method X-ray diffraction measurement was performed with an X-ray diffractometer (RINT2500 / PC, manufactured by Rigaku), a diffraction pattern unique to fcc platinum was shown, and the diffraction angle 2θ of the main peak (111) was 38.8 ° ( 220) From the diffraction peak, the crystallite diameter was calculated to be 2.0 nm. When this platinum black is observed with a transmission electron microscope TEM (manufactured by Hitachi, Ltd., H-800), as shown in FIG. 2, a secondary particle diameter of about 180 nm to 250 nm consisting of primary particles having a particle diameter of 2.0 to 3.0 nm is obtained. Aggregates were observed. The dry conversion oxygen content in the platinum black was analyzed to be 5.6% by mass using an oxygen / nitrogen analyzer (LECO Japan, TC-600). According to ICP analysis, the dry conversion contents of chlorine and Na were 250 ppm and 200 ppm, respectively. The content of alkali metals other than Na was below the lower limit of detection by ICP analysis.
＜実施例２＞白金ブラックコロイドの製造
実施例１で得た白金ブラック０．１０ｇを純水５０ｍｌに加え、１５分間超音波分散処理して黒色コロイドを得た。動的光散乱粒度分布計でこのコロイド粒子の粒径を測定したところ平均粒径Ｚ‐Ａｖｅｒａｇｅ１９５ｎｍ、多分散度指数ＰＤＩ０．１５であった。また、このコロイドのゼータ電位を、ゼータ電位測定装置（マルバーン社製、ゼータサイザーナノ）で測定したところ、マイナス４７ｍＶであった。
<Example 2> Production of platinum black colloid 0.10 g of platinum black obtained in Example 1 was added to 50 ml of pure water and subjected to ultrasonic dispersion treatment for 15 minutes to obtain a black colloid. When the particle size of the colloidal particles was measured with a dynamic light scattering particle size distribution meter, the average particle size was Z-Average 195 nm and the polydispersity index PDI was 0.15. In addition, the zeta potential of this colloid was measured with a zeta potential measuring device (manufactured by Malvern, Zeta Sizer Nano) and found to be minus 47 mV.
＜実施例３＞高比表面積白金ブラックの製造（酸素処理工程を経ない製法）
（ナノコロイド生成工程）
純水１．２Ｌに、氷酢酸０．７５ｇの１０ｍｌ純水溶液を添加し、これに白金０．７５ｇを含むヘキサヒドロキソ白金酸２‐エタノールアミン水溶液８．８３ｇの純水７．５ｍｌ希釈水溶液を滴下した以外は、実施例１のナノコロイド生成工程と同様にして、乳白色のヘキサヒドロキソ白金酸ナノコロイドを得た。
（還元工程）
上記ヘキサヒドロキソ白金酸ナノコロイドを合成空気流通下、攪拌しながらマントルヒータで加熱し４０分で９０℃へ昇温した。９０℃にて０．４６ｍｌの９８％蟻酸の１３ｍｌ純水溶液を滴下ロートから２０分間に亘って一定の滴下速度で滴下した。滴下終了後なお空気流通下９０℃で５時間攪拌を保持した。コロイドの色調は次第にグレー化したがブラックには変化しなかった。５時間後から、液温を９０℃に保持したまま、０．２３ｍｌの９８％蟻酸の６．５ｍｌ水溶液を１０分間掛けて滴下した。滴下２０分後にコロイドは濃いブラックに変化した。なお３０分間攪拌を保持した後、加熱を止め室温まで攪拌しながら冷却した。
（洗浄工程・乾燥工程）
得られたブラックのスラリーを実施例１の洗浄工程及び乾燥工程と同様に処理し、白金ブラック粉末０．７５ｇを得た。
（物性測定）
実施例１と同様に前処理後比表面積を測定して、ＢＥＴ比表面積８２ｍ２／ｇ、全細孔容積０．０４１ｃｍ３／ｇを得た。また粉末法Ｘ線回折でｆｃｃ白金（１１１）の回折角２θ ３８．９°、（２２０）結晶子径は２．２ｎｍであった。元素分析の結果、白金ブラック中の酸素含有率は４．６％、塩素およびＮａの含有率はそれぞれ、２７０ｐｐｍ、２００ｐｐｍであった。Ｎａ以外のアルカリ金属の含有率はＩＣＰ分析の検出下限以下であった。
<Example 3> Production of high specific surface area platinum black (production method without passing through oxygen treatment step)
(Nano colloid production process)
Add 0.75 g of glacial acetic acid in 10 ml of pure water to 1.2 L of pure water, and add dropwise dropwise dilute 7.5 ml of pure water in 8.83 g of hexahydroxoplatinic acid 2-ethanolamine containing 0.75 g of platinum. Except that, milky white hexahydroxoplatinic acid nanocolloid was obtained in the same manner as in the nanocolloid production step of Example 1.
(Reduction process)
The hexahydroxoplatinic acid nanocolloid was heated with a mantle heater while stirring under a synthetic air flow, and the temperature was raised to 90 ° C. in 40 minutes. At 90 ° C., 0.46 ml of a 13 ml pure aqueous solution of 98% formic acid was dropped from the dropping funnel at a constant dropping rate over 20 minutes. After completion of dropping, stirring was maintained at 90 ° C. for 5 hours under air flow. The color of the colloid gradually became gray but did not change to black. After 5 hours, while maintaining the liquid temperature at 90 ° C., 0.23 ml of a 6.5% aqueous solution of 98% formic acid was added dropwise over 10 minutes. The colloid turned dark black 20 minutes after the dropping. In addition, after hold | maintaining stirring for 30 minutes, the heating was stopped and it cooled, stirring to room temperature.
(Washing process / drying process)
The obtained black slurry was treated in the same manner as in the washing step and the drying step of Example 1 to obtain 0.75 g of platinum black powder.
(Physical property measurement)
The specific surface area after the pretreatment was measured in the same manner as in Example 1 to obtain a BET specific surface area of 82 m 2 / g and a total pore volume of 0.041 cm 3 / g. Moreover, the powder method X-ray diffraction showed that the diffraction angle of fcc platinum (111) was 2θ 38.9 ° and the (220) crystallite diameter was 2.2 nm. As a result of elemental analysis, the oxygen content in platinum black was 4.6%, and the chlorine and Na contents were 270 ppm and 200 ppm, respectively. The content of alkali metals other than Na was below the lower limit of detection by ICP analysis.
＜実施例４＞高比表面積白金ブラックの製造（酸素処理工程を経る製法）
（ナノコロイド生成工程）
実施例１のナノコロイド生成工程と同様にして、白金１．５０ｇを含むヘキサヒドロキソ白金酸の乳白色ナノコロイドを得た。
（還元工程）
上記コロイドを合成空気流通下、攪拌しながらマントルヒータで加熱し４０分で９０℃へ昇温した。９０℃にて０．９２ｍｌの９８％蟻酸の２５ｍｌ純水溶液を滴下ロートから４０分間に亘って一定の滴下速度で滴下した。滴下終了後も、液温９０℃で攪拌を３時間保持した。滴下開始の１時間後からコロイドの色調は少しずつグレーに変わり以降グレーが次第に濃くなり、３時間後に濃いブラックに変化した。濃いブラックに変化してなお９０℃で３０分間攪拌保持した後、加熱を止め室温まで攪拌しながら冷却した。
（酸素処理工程）
液温３０℃まで冷却した時点で、側管から合成空気を３００ｍＬ／ｍｉｎの流量で吹き込みながら攪拌し３０分保持した。
（洗浄工程・乾燥工程）
得られたブラックのスラリーを実施例１の洗浄工程・乾燥工程と同様に処理し、白金ブラック粉末１．５０ｇを得た。
（物性測定）
実施例１と同様に前処理後比表面積を測定して、ＢＥＴ比表面積１０３ｍ２／ｇ、細孔容積０．０４７ｃｍ３／ｇを得た。また粉末法Ｘ線回折でｆｃｃ白金（１１１）の回折角２θ ３８．７°、（２２０）結晶子径は１．９ｎｍであった。元素分析の結果、白金ブラック中の酸素含有率は６．１％、塩素およびアルカリ金属の含有率はそれぞれ、２００ｐｐｍ、１５０ｐｐｍであった。Ｎａ以外のアルカリ金属の含有率はＩＣＰ分析の検出下限以下であった。
<Example 4> Production of high specific surface area platinum black (production method through an oxygen treatment step)
(Nano colloid production process)
In the same manner as in the nanocolloid production step of Example 1, a milky white nanocolloid of hexahydroxoplatinic acid containing 1.50 g of platinum was obtained.
(Reduction process)
The colloid was heated with a mantle heater while stirring under a synthetic air flow, and the temperature was raised to 90 ° C. in 40 minutes. At 90 ° C., 0.92 ml of 25% pure aqueous solution of 98% formic acid was dropped from the dropping funnel over 40 minutes at a constant dropping rate. Even after completion of the dropwise addition, stirring was maintained at a liquid temperature of 90 ° C. for 3 hours. From 1 hour after the start of dropping, the color of the colloid gradually changed to gray. After that, the gray gradually became darker, and changed to dark black after 3 hours. After changing to dark black and maintaining stirring at 90 ° C. for 30 minutes, the heating was stopped and the mixture was cooled to room temperature with stirring.
(Oxygen treatment process)
When the liquid temperature was cooled to 30 ° C., the mixture was stirred for 30 minutes while blowing synthetic air from the side tube at a flow rate of 300 mL / min.
(Washing process / drying process)
The obtained black slurry was treated in the same manner as in the washing and drying steps of Example 1 to obtain 1.50 g of platinum black powder.
(Physical property measurement)
The specific surface area after pretreatment was measured in the same manner as in Example 1 to obtain a BET specific surface area of 103 m 2 / g and a pore volume of 0.047 cm 3 / g. Further, the powder method X-ray diffraction revealed that the diffraction angle of fcc platinum (111) was 2θ 38.7 ° and the (220) crystallite diameter was 1.9 nm. As a result of elemental analysis, the oxygen content in platinum black was 6.1%, and the chlorine and alkali metal contents were 200 ppm and 150 ppm, respectively. The content of alkali metals other than Na was below the lower limit of detection by ICP analysis.
＜比較例１＞従来の白金ブラックの製造
特許文献１に記載された実施例１の製法に従い、次のように処理した。白金１．５０ｇに相当するヘキサヒドロキソ白金酸の白色結晶２．３４ｇを３１．４質量％の硝酸水溶液２７．６ｇに溶解させた。５００ｍｌの四つ口フラスコにこのヘキサヒドロキソ白金酸の硝酸水溶液を入れ、これをテフロン（登録商標）攪拌羽根で十分良く攪拌しながら、側管の滴下ロートから純水１２６ｍｌを１時間に亘ってゆっくり滴下した。滴下終了後なお３０分攪拌保持し、次いでマントルヒータで加熱し２時間かけて７０℃へ昇温し、７０℃で１時間攪拌保持し、オレンジ色の懸濁液を得た。これを７０℃で攪拌しながら、濃アンモニア水１２ｍｌを滴下し、懸濁液のｐＨが５．０になるまで中和した。次いで、マイクロフィーダーを用いて１．５０ｍｌの蟻酸１時間に亘り一定速度で添加した。懸濁液の色調がオレンジからブラックに変化した。滴下終了後、なお攪拌を１時間保持した後、室温まで放冷し、沈降した白金ブラックをろ過した。濾液の電導度が２．０μｓ／ｃｍ以下となるまで純水で洗浄し、風乾後、１２０℃において乾燥された。実施例１と同様に表面積を測定し、５３ｍ２／ｇの比表面積、０．０２５ｃｍ３／ｇの全細孔容積を得た。この白金ブラックの粉末法Ｘ線回折はｆｃｃ白金の（２２０）結晶子径が５．１ｎｍであることを示した。
<Comparative Example 1> Production of Conventional Platinum Black According to the production method of Example 1 described in Patent Document 1, treatment was performed as follows. 2.34 g of hexahydroxoplatinic acid white crystals corresponding to 1.50 g of platinum were dissolved in 27.6 g of a 31.4 mass% nitric acid aqueous solution. Put the hexahydroxoplatinic acid aqueous solution of hexahydroxoplatinic acid into a 500 ml four-necked flask, and stir it well with a Teflon (registered trademark) stirring blade, and slowly add 126 ml of pure water from the dropping funnel of the side tube over 1 hour. It was dripped. After completion of dropping, the mixture was stirred and held for 30 minutes, then heated with a mantle heater, heated to 70 ° C. over 2 hours, and stirred and held at 70 ° C. for 1 hour to obtain an orange suspension. While stirring this at 70 ° C., 12 ml of concentrated aqueous ammonia was added dropwise to neutralize the suspension until the pH of the suspension was 5.0. Then, 1.50 ml of formic acid was added at a constant rate over 1 hour using a microfeeder. The color of the suspension changed from orange to black. After completion of the dropwise addition, the stirring was kept for 1 hour, and then allowed to cool to room temperature, and the precipitated platinum black was filtered. The filtrate was washed with pure water until the conductivity was 2.0 μs / cm or less, air-dried, and dried at 120 ° C. Similarly to measure the surface area as in Example 1 to obtain a specific surface area of 53m 2 / g, a total pore volume of 0.025 cm 3 / g. The powder method X-ray diffraction of this platinum black showed that the (220) crystallite diameter of fcc platinum was 5.1 nm.
本発明に係る白金ブラック粉末及び白金のブラックコロイドは、例えば、ファィンケミカルの水素化用触媒又は酸化用触媒、或いは、燃料電池、電解セル及び電気化学的センサの用途におけるガス拡散電極用触媒として利用できる。 The platinum black powder and the platinum black colloid according to the present invention are, for example, a fin chemical hydrogenation catalyst or oxidation catalyst, or a gas diffusion electrode catalyst for use in fuel cells, electrolysis cells and electrochemical sensors. Available as
Claims (12)
前記ナノコロイドに還元剤を添加して前記ナノコロイドを還元し、白金含有コロイドを形成する還元工程と、
前記白金含有コロイドをろ過し純水洗浄する洗浄工程と、
洗浄した白金含有コロイドを乾燥する乾燥工程と、
を有することを特徴とする白金ブラック粉末の製造方法。 A nanocolloid production step of producing a hexahydroxoplatinic acid nanocolloid in the liquid phase;
A reducing step of adding a reducing agent to the nanocolloid to reduce the nanocolloid to form a platinum-containing colloid;
A washing step of filtering the platinum-containing colloid and washing with pure water;
A drying step of drying the washed platinum-containing colloid;
A method for producing platinum black powder, comprising:
前記ナノコロイドに還元剤を添加して前記ナノコロイドを還元し、白金含有コロイドを形成する還元工程と、
前記白金含有コロイドをろ過し純水洗浄する洗浄工程と、
洗浄した白金含有コロイドを溶媒に分散する分散工程と、
を有することを特徴とする白金ブラックコロイドの製造方法。 A nanocolloid production step of producing a hexahydroxoplatinic acid nanocolloid in the liquid phase;
A reducing step of adding a reducing agent to the nanocolloid to reduce the nanocolloid to form a platinum-containing colloid;
A washing step of filtering the platinum-containing colloid and washing with pure water;
A dispersion step of dispersing the washed platinum-containing colloid in a solvent;
A method for producing a platinum black colloid characterized by comprising:
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009005161A JP5451083B2 (en) | 2009-01-13 | 2009-01-13 | Platinum black powder, colloid of platinum black and process for producing them |
| PCT/JP2009/071740 WO2010082443A1 (en) | 2009-01-13 | 2009-12-28 | Platinum black powder, platinum black colloid, method for producing platinum black powder, and method for producing platinum black colloid |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009005161A JP5451083B2 (en) | 2009-01-13 | 2009-01-13 | Platinum black powder, colloid of platinum black and process for producing them |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2010162443A true JP2010162443A (en) | 2010-07-29 |
| JP5451083B2 JP5451083B2 (en) | 2014-03-26 |
Family
ID=42339698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009005161A Active JP5451083B2 (en) | 2009-01-13 | 2009-01-13 | Platinum black powder, colloid of platinum black and process for producing them |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP5451083B2 (en) |
| WO (1) | WO2010082443A1 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013026014A (en) * | 2011-07-21 | 2013-02-04 | Honda Motor Co Ltd | Catalyst for fuel cell and manufacturing method of catalyst for fuel cell |
| JP2014101240A (en) * | 2012-11-19 | 2014-06-05 | Hitachi-Ge Nuclear Energy Ltd | Platinum oxide colloid solution and manufacturing method and manufacturing apparatus of the same |
| JP5701466B1 (en) * | 2013-12-27 | 2015-04-15 | 昭和電工株式会社 | Method for producing electrode catalyst for fuel cell |
| JP2015085226A (en) * | 2013-10-29 | 2015-05-07 | 石福金属興業株式会社 | Composition for production of supported catalyst |
| WO2015098181A1 (en) * | 2013-12-27 | 2015-07-02 | 昭和電工株式会社 | Method for producing electrode catalyst for fuel cells |
| JP2016505193A (en) * | 2012-08-29 | 2016-02-18 | ソルビコア・ゲーエムベーハー・ウント・コ・カーゲー | Colloidal dispersions containing noble metal particles and acidic ionomer components and methods for their production and use |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104416164B (en) * | 2013-09-04 | 2017-01-04 | 中国科学院苏州纳米技术与纳米仿生研究所 | Platinum black and preparation method thereof |
| US10457583B2 (en) * | 2016-03-31 | 2019-10-29 | Hitachi-Ge Nuclear Energy, Ltd. | Method for relieving corrosive environment of boiling water reactor, nuclear power plant, and method for injecting noble metal which is carried out in nuclear power plant |
| JP6899302B2 (en) * | 2017-09-29 | 2021-07-07 | 日立Ｇｅニュークリア・エナジー株式会社 | Method for producing platinum oxide colloidal solution |
| CN111745164B (en) * | 2020-07-14 | 2022-12-23 | 昆明理工大学 | Preparation method of superfine spherical platinum powder |
| CN113681023B (en) * | 2021-08-18 | 2023-09-05 | 中国科学院城市环境研究所 | Regular-morphology nano platinum black and preparation method and application thereof |
| WO2024042610A1 (en) * | 2022-08-23 | 2024-02-29 | 株式会社Ｃｅｐプロジェクト | Method for producing platinum nano-particle solution, antibacterial agent, and antibacterial product |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04157193A (en) * | 1990-10-19 | 1992-05-29 | Tome Sangyo Kk | Production of superfine metal grain |
| JP2003034801A (en) * | 2001-07-27 | 2003-02-07 | Noritake Co Ltd | Metal powder and manufacturing method therefor |
| JP2003129102A (en) * | 2001-08-04 | 2003-05-08 | Omg Ag & Co Kg | Powder of platinum and platinum alloy with high surface area and low chlorine content, and process for preparing the same |
| JP2003221601A (en) * | 2002-01-31 | 2003-08-08 | Japan Science & Technology Corp | Porous body of noble metal and manufacturing method therefor |
| JP2004027346A (en) * | 2002-06-28 | 2004-01-29 | Japan Science & Technology Corp | Hydrogen storage body |
| WO2004012884A1 (en) * | 2002-08-01 | 2004-02-12 | Daiken Chemical Co., Ltd. | Metal nanoparticle and process for producing the same |
| JP2004263222A (en) * | 2003-02-28 | 2004-09-24 | Tanaka Kikinzoku Kogyo Kk | Mono-component system or multicomponent system metal colloid, and method for manufacturing mono-component system or multicomponent system metal colloid |
| WO2006088194A1 (en) * | 2005-02-21 | 2006-08-24 | Nissan Motor Co., Ltd. | Electrode catalyst and method for producing same |
| JP2006322051A (en) * | 2005-05-19 | 2006-11-30 | Noritake Co Ltd | Metal powder, and method for producing the same |
| JP2007100117A (en) * | 2005-09-30 | 2007-04-19 | Kanto Chem Co Inc | Metal nanoparticle, catalyst comprising the same and method for hydrogenating alkyne compound |
| JP2007123108A (en) * | 2005-10-28 | 2007-05-17 | Catalysts & Chem Ind Co Ltd | Platinum colloid carried carbon and its manufacturing method |
| JP2008038206A (en) * | 2006-08-07 | 2008-02-21 | Mitsubishi Materials Corp | Platinum powder for platinum clay, and platinum clay comprising the platinum powder |
-
2009
- 2009-01-13 JP JP2009005161A patent/JP5451083B2/en active Active
- 2009-12-28 WO PCT/JP2009/071740 patent/WO2010082443A1/en active Application Filing
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04157193A (en) * | 1990-10-19 | 1992-05-29 | Tome Sangyo Kk | Production of superfine metal grain |
| JP2003034801A (en) * | 2001-07-27 | 2003-02-07 | Noritake Co Ltd | Metal powder and manufacturing method therefor |
| JP2003129102A (en) * | 2001-08-04 | 2003-05-08 | Omg Ag & Co Kg | Powder of platinum and platinum alloy with high surface area and low chlorine content, and process for preparing the same |
| JP2003221601A (en) * | 2002-01-31 | 2003-08-08 | Japan Science & Technology Corp | Porous body of noble metal and manufacturing method therefor |
| JP2004027346A (en) * | 2002-06-28 | 2004-01-29 | Japan Science & Technology Corp | Hydrogen storage body |
| WO2004012884A1 (en) * | 2002-08-01 | 2004-02-12 | Daiken Chemical Co., Ltd. | Metal nanoparticle and process for producing the same |
| JP2004263222A (en) * | 2003-02-28 | 2004-09-24 | Tanaka Kikinzoku Kogyo Kk | Mono-component system or multicomponent system metal colloid, and method for manufacturing mono-component system or multicomponent system metal colloid |
| WO2006088194A1 (en) * | 2005-02-21 | 2006-08-24 | Nissan Motor Co., Ltd. | Electrode catalyst and method for producing same |
| JP2006322051A (en) * | 2005-05-19 | 2006-11-30 | Noritake Co Ltd | Metal powder, and method for producing the same |
| JP2007100117A (en) * | 2005-09-30 | 2007-04-19 | Kanto Chem Co Inc | Metal nanoparticle, catalyst comprising the same and method for hydrogenating alkyne compound |
| JP2007123108A (en) * | 2005-10-28 | 2007-05-17 | Catalysts & Chem Ind Co Ltd | Platinum colloid carried carbon and its manufacturing method |
| JP2008038206A (en) * | 2006-08-07 | 2008-02-21 | Mitsubishi Materials Corp | Platinum powder for platinum clay, and platinum clay comprising the platinum powder |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013026014A (en) * | 2011-07-21 | 2013-02-04 | Honda Motor Co Ltd | Catalyst for fuel cell and manufacturing method of catalyst for fuel cell |
| JP2016505193A (en) * | 2012-08-29 | 2016-02-18 | ソルビコア・ゲーエムベーハー・ウント・コ・カーゲー | Colloidal dispersions containing noble metal particles and acidic ionomer components and methods for their production and use |
| JP2014101240A (en) * | 2012-11-19 | 2014-06-05 | Hitachi-Ge Nuclear Energy Ltd | Platinum oxide colloid solution and manufacturing method and manufacturing apparatus of the same |
| JP2015085226A (en) * | 2013-10-29 | 2015-05-07 | 石福金属興業株式会社 | Composition for production of supported catalyst |
| JP5701466B1 (en) * | 2013-12-27 | 2015-04-15 | 昭和電工株式会社 | Method for producing electrode catalyst for fuel cell |
| WO2015098181A1 (en) * | 2013-12-27 | 2015-07-02 | 昭和電工株式会社 | Method for producing electrode catalyst for fuel cells |
| US9947940B2 (en) | 2013-12-27 | 2018-04-17 | Showa Denko K.K. | Method for producing fuel cell electrode catalyst |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2010082443A1 (en) | 2010-07-22 |
| JP5451083B2 (en) | 2014-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5451083B2 (en) | Platinum black powder, colloid of platinum black and process for producing them | |
| Shi et al. | Controllable deposition of platinum nanoparticles on polyaniline-functionalized carbon nanotubes | |
| Yang et al. | Carbon nanotubes decorated with Pt nanocubes by a noncovalent functionalization method and their role in oxygen reduction | |
| Fu et al. | Synthesis and electrocatalytic activity of Au@ Pd core-shell nanothorns for the oxygen reduction reaction | |
| Ye et al. | Green synthesis of Pt–Au dendrimer-like nanoparticles supported on polydopamine-functionalized graphene and their high performance toward 4-nitrophenol reduction | |
| Mohanta et al. | Tin oxide nanostructured materials: an overview of recent developments in synthesis, modifications and potential applications | |
| Wang et al. | Controlled synthesis of dendritic Au@ Pt core–shell nanomaterials for use as an effective fuel cell electrocatalyst | |
| Zheng et al. | Popcorn-like PtAu nanoparticles supported on reduced graphene oxide: facile synthesis and catalytic applications | |
| Fu et al. | Polyallylamine-directed green synthesis of platinum nanocubes. Shape and electronic effect codependent enhanced electrocatalytic activity | |
| Hueso et al. | Beyond gold: rediscovering tetrakis-(hydroxymethyl)-phosphonium chloride (THPC) as an effective agent for the synthesis of ultra-small noble metal nanoparticles and Pt-containing nanoalloys | |
| Zhang et al. | Simple one-pot preparation of Pd-on-Cu nanocrystals supported on reduced graphene oxide for enhanced ethanol electrooxidation | |
| CN107249735A (en) | Carbon supported catalyst comprising modifying agent and the method for preparing carbon supported catalyst | |
| Ye et al. | Synthesis of chestnut-bur-like palladium nanostructures and their enhanced electrocatalytic activities for ethanol oxidation | |
| JP6653875B2 (en) | Method for producing platinum catalyst and fuel cell using the same | |
| Tang et al. | Facile and rapid synthesis of spherical porous palladium nanostructures with high catalytic activity for formic acid electro-oxidation | |
| He et al. | One-step solid state synthesis of PtCo nanocubes/graphene nanocomposites as advanced oxygen reduction reaction electrocatalysts | |
| Zhang et al. | Facile assembly of silica gel/reduced graphene oxide/Ag nanoparticle composite with a core–shell structure and its excellent catalytic properties | |
| Fu et al. | L-Lysine mediated synthesis of platinum nanocuboids and their electrocatalytic activity towards ammonia oxidation | |
| Zheng et al. | Hollow titania spheres loaded with noble metal nanoparticles for photocatalytic water oxidation | |
| Odoom-Wubah et al. | Ascorbic acid assisted bio-synthesis of Pd-Pt nanoflowers with enhanced electrochemical properties. | |
| Zhang et al. | Polyaniline decorated MoO3 nanorods: synthesis, characterization and promoting effect to Pt electrocatalyst | |
| JP5400924B2 (en) | Method for producing gold-supported carbon catalyst | |
| Liu et al. | One-pot synthesis of flower-like Bi2WO6/BiOCOOH microspheres with enhanced visible light photocatalytic activity | |
| Wu et al. | Silver nanoparticles stabilized by bundled tungsten oxide nanowires with catalytic and antibacterial activities | |
| WO2012127540A1 (en) | Metal oxide-platinum compound catalyst and method for producing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20111216 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20130723 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130920 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20130924 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20131203 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20131226 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5451083 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |