JP6086809B2 - Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material - Google Patents
Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material Download PDFInfo
- Publication number
- JP6086809B2 JP6086809B2 JP2013098493A JP2013098493A JP6086809B2 JP 6086809 B2 JP6086809 B2 JP 6086809B2 JP 2013098493 A JP2013098493 A JP 2013098493A JP 2013098493 A JP2013098493 A JP 2013098493A JP 6086809 B2 JP6086809 B2 JP 6086809B2
- Authority
- JP
- Japan
- Prior art keywords
- metal oxide
- porous inorganic
- electrode material
- inorganic material
- oxide particles
- 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.)
- Active
Links
- 239000007772 electrode material Substances 0.000 title claims description 44
- 239000000446 fuel Substances 0.000 title claims description 43
- 239000012528 membrane Substances 0.000 title claims description 36
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- 239000003054 catalyst Substances 0.000 claims description 73
- 229910044991 metal oxide Inorganic materials 0.000 claims description 65
- 150000004706 metal oxides Chemical class 0.000 claims description 65
- 239000002245 particle Substances 0.000 claims description 63
- 229910010272 inorganic material Inorganic materials 0.000 claims description 58
- 239000011147 inorganic material Substances 0.000 claims description 58
- 125000000524 functional group Chemical group 0.000 claims description 42
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 32
- 239000001301 oxygen Substances 0.000 claims description 32
- 229910052760 oxygen Inorganic materials 0.000 claims description 32
- 239000003792 electrolyte Substances 0.000 claims description 22
- 239000011148 porous material Substances 0.000 claims description 22
- -1 organosilane compound Chemical class 0.000 claims description 20
- 230000009467 reduction Effects 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 17
- 239000011248 coating agent Substances 0.000 claims description 15
- 238000000576 coating method Methods 0.000 claims description 15
- 125000001453 quaternary ammonium group Chemical group 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- 229910052757 nitrogen Inorganic materials 0.000 claims description 9
- 229910052741 iridium Inorganic materials 0.000 claims description 6
- 125000003277 amino group Chemical group 0.000 claims description 5
- 229910052787 antimony Inorganic materials 0.000 claims description 5
- 229910052746 lanthanum Inorganic materials 0.000 claims description 5
- 229910052758 niobium Inorganic materials 0.000 claims description 5
- 229910052707 ruthenium Inorganic materials 0.000 claims description 5
- 229910052715 tantalum Inorganic materials 0.000 claims description 5
- 229910052718 tin Inorganic materials 0.000 claims description 5
- 229910052719 titanium Inorganic materials 0.000 claims description 5
- 229910052720 vanadium Inorganic materials 0.000 claims description 5
- 229910052727 yttrium Inorganic materials 0.000 claims description 5
- 229910052726 zirconium Inorganic materials 0.000 claims description 5
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 4
- 229910052691 Erbium Inorganic materials 0.000 claims description 4
- 229910052693 Europium Inorganic materials 0.000 claims description 4
- 229910052688 Gadolinium Inorganic materials 0.000 claims description 4
- 229910052689 Holmium Inorganic materials 0.000 claims description 4
- 229910052779 Neodymium Inorganic materials 0.000 claims description 4
- 229910052777 Praseodymium Inorganic materials 0.000 claims description 4
- 229910052772 Samarium Inorganic materials 0.000 claims description 4
- 229910052771 Terbium Inorganic materials 0.000 claims description 4
- 229910052775 Thulium Inorganic materials 0.000 claims description 4
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 4
- 229910052735 hafnium Inorganic materials 0.000 claims description 4
- 125000004433 nitrogen atom Chemical group N* 0.000 claims description 3
- 125000002924 primary amino group Chemical class [H]N([H])* 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 3
- 125000000467 secondary amino group Chemical class [H]N([*:1])[*:2] 0.000 claims description 3
- MKZHJJQCUIZEDE-UHFFFAOYSA-N 1-[(2-hydroxy-3-naphthalen-1-yloxypropyl)-propan-2-ylamino]-3-naphthalen-1-yloxypropan-2-ol Chemical compound C1=CC=C2C(OCC(O)CN(CC(O)COC=3C4=CC=CC=C4C=CC=3)C(C)C)=CC=CC2=C1 MKZHJJQCUIZEDE-UHFFFAOYSA-N 0.000 claims description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 2
- 239000010411 electrocatalyst Substances 0.000 claims 2
- 239000007789 gas Substances 0.000 description 48
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 30
- 229910004298 SiO 2 Inorganic materials 0.000 description 27
- 238000006722 reduction reaction Methods 0.000 description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 21
- 238000009792 diffusion process Methods 0.000 description 20
- 238000010248 power generation Methods 0.000 description 19
- 230000000694 effects Effects 0.000 description 18
- 239000007864 aqueous solution Substances 0.000 description 16
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 15
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 15
- 229920000554 ionomer Polymers 0.000 description 15
- 238000005119 centrifugation Methods 0.000 description 14
- 239000004020 conductor Substances 0.000 description 14
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 14
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 12
- 238000010304 firing Methods 0.000 description 11
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 239000005518 polymer electrolyte Substances 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 9
- 230000002378 acidificating effect Effects 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 9
- 150000002500 ions Chemical class 0.000 description 9
- 238000002156 mixing Methods 0.000 description 8
- 239000002243 precursor Substances 0.000 description 8
- 229910000077 silane Inorganic materials 0.000 description 8
- 239000002002 slurry Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 7
- 229920000557 Nafion® Polymers 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- 230000003197 catalytic effect Effects 0.000 description 7
- 238000003411 electrode reaction Methods 0.000 description 7
- 239000001257 hydrogen Substances 0.000 description 7
- 229910052739 hydrogen Inorganic materials 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000007800 oxidant agent Substances 0.000 description 7
- 230000001590 oxidative effect Effects 0.000 description 7
- WYTZZXDRDKSJID-UHFFFAOYSA-N (3-aminopropyl)triethoxysilane Chemical compound CCO[Si](OCC)(OCC)CCCN WYTZZXDRDKSJID-UHFFFAOYSA-N 0.000 description 6
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 239000011261 inert gas Substances 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 229920000642 polymer Polymers 0.000 description 5
- 238000009210 therapy by ultrasound Methods 0.000 description 5
- 238000002411 thermogravimetry Methods 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- AACHVWXCVWWMSI-UHFFFAOYSA-N 3-hydroxypropyl(trimethyl)azanium Chemical group C[N+](C)(C)CCCO AACHVWXCVWWMSI-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 230000010757 Reduction Activity Effects 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 4
- 239000010406 cathode material Substances 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- JMCRETWEZLOFQT-UHFFFAOYSA-M trimethyl(3-triethoxysilylpropyl)azanium;chloride Chemical compound [Cl-].CCO[Si](OCC)(OCC)CCC[N+](C)(C)C JMCRETWEZLOFQT-UHFFFAOYSA-M 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 239000006229 carbon black Substances 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 229910052734 helium Inorganic materials 0.000 description 3
- 239000001307 helium Substances 0.000 description 3
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 3
- RLJMLMKIBZAXJO-UHFFFAOYSA-N lead nitrate Chemical compound [O-][N+](=O)O[Pb]O[N+]([O-])=O RLJMLMKIBZAXJO-UHFFFAOYSA-N 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- ZLDHYRXZZNDOKU-UHFFFAOYSA-N n,n-diethyl-3-trimethoxysilylpropan-1-amine Chemical compound CCN(CC)CCC[Si](OC)(OC)OC ZLDHYRXZZNDOKU-UHFFFAOYSA-N 0.000 description 3
- 238000006386 neutralization reaction Methods 0.000 description 3
- 239000003002 pH adjusting agent Substances 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 238000012643 polycondensation polymerization Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- OXFZKAYNTQHYEG-UHFFFAOYSA-N 5-aminopentan-2-yl triethyl silicate Chemical compound CCO[Si](OCC)(OCC)OC(C)CCCN OXFZKAYNTQHYEG-UHFFFAOYSA-N 0.000 description 2
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 2
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical compound OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 description 2
- 239000004696 Poly ether ether ketone Substances 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 125000003118 aryl group Chemical group 0.000 description 2
- 239000002585 base Substances 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 2
- KFIKNZBXPKXFTA-UHFFFAOYSA-N dipotassium;dioxido(dioxo)ruthenium Chemical compound [K+].[K+].[O-][Ru]([O-])(=O)=O KFIKNZBXPKXFTA-UHFFFAOYSA-N 0.000 description 2
- 239000002737 fuel gas Substances 0.000 description 2
- 150000004820 halides Chemical class 0.000 description 2
- 238000007731 hot pressing Methods 0.000 description 2
- 229910052745 lead Inorganic materials 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229920002492 poly(sulfone) Polymers 0.000 description 2
- 229920002530 polyetherether ketone Polymers 0.000 description 2
- 150000003141 primary amines Chemical class 0.000 description 2
- 150000003335 secondary amines Chemical class 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 125000000542 sulfonic acid group Chemical group 0.000 description 2
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- XMWRBQBLMFGWIX-UHFFFAOYSA-N C60 fullerene Chemical compound C12=C3C(C4=C56)=C7C8=C5C5=C9C%10=C6C6=C4C1=C1C4=C6C6=C%10C%10=C9C9=C%11C5=C8C5=C8C7=C3C3=C7C2=C1C1=C2C4=C6C4=C%10C6=C9C9=C%11C5=C5C8=C3C3=C7C1=C1C2=C4C6=C2C9=C5C3=C12 XMWRBQBLMFGWIX-UHFFFAOYSA-N 0.000 description 1
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- GEIAQOFPUVMAGM-UHFFFAOYSA-N ZrO Inorganic materials [Zr]=O GEIAQOFPUVMAGM-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000006230 acetylene black Substances 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 125000002490 anilino group Chemical group [H]N(*)C1=C([H])C([H])=C([H])C([H])=C1[H] 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052797 bismuth Inorganic materials 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Substances 0.000 description 1
- 229910021393 carbon nanotube Inorganic materials 0.000 description 1
- 239000002041 carbon nanotube Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229910003472 fullerene Inorganic materials 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000003273 ketjen black Substances 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- PHQOGHDTIVQXHL-UHFFFAOYSA-N n'-(3-trimethoxysilylpropyl)ethane-1,2-diamine Chemical compound CO[Si](OC)(OC)CCCNCCN PHQOGHDTIVQXHL-UHFFFAOYSA-N 0.000 description 1
- DVYVMJLSUSGYMH-UHFFFAOYSA-N n-methyl-3-trimethoxysilylpropan-1-amine Chemical compound CNCCC[Si](OC)(OC)OC DVYVMJLSUSGYMH-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- IEQIEDJGQAUEQZ-UHFFFAOYSA-N phthalocyanine Chemical compound N1C(N=C2C3=CC=CC=C3C(N=C3C4=CC=CC=C4C(=N4)N3)=N2)=C(C=CC=C2)C2=C1N=C1C2=CC=CC=C2C4=N1 IEQIEDJGQAUEQZ-UHFFFAOYSA-N 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 229910052702 rhenium Inorganic materials 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 150000003512 tertiary amines Chemical class 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- CPUDPFPXCZDNGI-UHFFFAOYSA-N triethoxy(methyl)silane Chemical compound CCO[Si](C)(OCC)OCC CPUDPFPXCZDNGI-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 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
- H01M4/9016—Oxides, hydroxides or oxygenated metallic salts
-
- 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
- H01M4/8647—Inert electrodes with catalytic activity, e.g. for fuel cells consisting of more than one material, e.g. consisting of composites
- H01M4/8657—Inert electrodes with catalytic activity, e.g. for fuel cells consisting of more than one material, e.g. consisting of composites layered
-
- 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
- H01M4/88—Processes of manufacture
- H01M4/8825—Methods for deposition of the catalytic active composition
- H01M4/8828—Coating with slurry or ink
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/10—Fuel cells with solid electrolytes
- H01M2008/1095—Fuel cells with polymeric electrolytes
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Composite Materials (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inert Electrodes (AREA)
- Fuel Cell (AREA)
- Catalysts (AREA)
Description
本発明は、燃料電池などに用いられる電極材料に関する。 The present invention relates to an electrode material used for a fuel cell or the like.
固体高分子形燃料電池は、アノード（燃料極）に水素を含む燃料ガス、カソード（空気極）に酸素を含む酸化剤ガスを供給し、以下の電気化学反応により発電する装置である。
アノード：Ｈ２→２Ｈ＋+２ｅ−・・・（１）
カソード：１／２Ｏ２+２Ｈ＋+２ｅ−→Ｈ２Ｏ・・・（２）
A polymer electrolyte fuel cell is a device that supplies a fuel gas containing hydrogen to an anode (fuel electrode) and an oxidant gas containing oxygen to a cathode (air electrode), and generates power by the following electrochemical reaction.
Anode: H 2 → 2H + + 2e − (1)
Cathode: 1 / 2O 2 + 2H + + 2e - → H 2 O ··· (2)
アノードおよびカソードは、それぞれ触媒層とガス拡散層が積層した構造からなる。触媒層は、触媒を担持した炭素粒子とプロトン伝導性イオノマーにより構成される層である。ガス拡散層は、酸化剤ガスや燃料ガスの通過経路となる。各電極の触媒層がプロトン伝導性電解質膜を挟んで対向配置され、膜電極接合体が構成される。 The anode and cathode each have a structure in which a catalyst layer and a gas diffusion layer are laminated. The catalyst layer is a layer composed of carbon particles carrying a catalyst and a proton conductive ionomer. The gas diffusion layer becomes a passage for the oxidant gas and the fuel gas. The catalyst layers of the electrodes are arranged to face each other with the proton conductive electrolyte membrane interposed therebetween, thereby forming a membrane electrode assembly.
カソード触媒層は強酸性かつ高電位という過酷な雰囲気であるため、触媒には高い化学的安定性が求められる。さらに、カソード反応（酸素還元反応）の反応速度は非常に遅いため、触媒には高い酸素還元活性が求められる。現在、カソード触媒として、ＰｔまたはＰｔ合金が用いられているが、Ｐｔは非常に高価であるため、Ｐｔを含まない、より安価な触媒を用いることが望まれている。 Since the cathode catalyst layer has a harsh atmosphere of strong acidity and high potential, the catalyst is required to have high chemical stability. Furthermore, since the reaction rate of the cathode reaction (oxygen reduction reaction) is very slow, the catalyst is required to have high oxygen reduction activity. Currently, Pt or a Pt alloy is used as the cathode catalyst. However, since Pt is very expensive, it is desired to use a cheaper catalyst that does not contain Pt.
Ｐｔ以外の酸素還元触媒として、特許文献１に記載のパイロクロア型酸化物のような、金属酸化物系触媒が挙げられる。これらは、特に塩基性雰囲気下で高い酸素還元活性を有することが知られている。 Examples of oxygen reduction catalysts other than Pt include metal oxide catalysts such as the pyrochlore oxide described in Patent Document 1. These are known to have high oxygen reduction activity particularly in a basic atmosphere.
しかしながら、強酸性のカソード環境下では、これら金属酸化物系触媒は触媒活性及び耐久性が不十分であった。 However, in a highly acidic cathode environment, these metal oxide catalysts have insufficient catalytic activity and durability.
本発明はこうした課題に鑑みてなされたものであり、その目的は、燃料電池や電解セルなどに用いられる、金属酸化物系触媒の触媒活性及び耐久性を向上させる技術の提供にある。 This invention is made | formed in view of such a subject, The objective is to provide the technique which improves the catalyst activity and durability of a metal oxide type catalyst used for a fuel cell, an electrolysis cell, etc.
本発明のある態様は電極材料である。当該電極材料は、酸素還元に活性を有する金属酸化物粒子を含む電極触媒と、前記金属酸化物粒子の表面の少なくとも一部を被覆する多孔性無機材料と、を備えることを特徴とする。 One embodiment of the present invention is an electrode material. The electrode material includes an electrode catalyst including metal oxide particles having activity for oxygen reduction, and a porous inorganic material that covers at least a part of the surface of the metal oxide particles.
上記態様の電極材料において、前記多孔性無機材料が、シリカ（ＳｉＯ２）を含んでもよい。前記多孔性無機材料が、塩基性官能基を含んでもよい。前記塩基性官能基が、窒素原子を含んでもよい。前記塩基性官能基が、第一級アミン誘導体、第二級アミン誘導体、第三級アミン誘導体、または第四級アンモニウム誘導体のうち少なくとも１種以上を含んでもよい。前記金属酸化物が、一般式Ａ２Ｂ２Ｏ７−Ｚ（ただし、ＡおよびＢはそれぞれ金属元素を表し、Ｚは０以上１以下の数を表し、ＡはＬａ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｐｂ、Ｂｉ、Ｍｎ、及びＹからなる群から選ばれる少なくとも一種を含み、ＢはＲｕ、Ｚｒ、Ｓｎ、Ｈｆ、Ｔｉ、Ｔａ、Ｎｂ、Ｖ、Ｓｂ、及びＩｒからなる群から選ばれる少なくとも一種を含む。）で表されるパイロクロア型酸化物であってもよい。 In the electrode material of the above aspect, the porous inorganic material may contain silica (SiO 2 ). The porous inorganic material may include a basic functional group. The basic functional group may contain a nitrogen atom. The basic functional group may include at least one of a primary amine derivative, a secondary amine derivative, a tertiary amine derivative, or a quaternary ammonium derivative. The metal oxide has the general formula A 2 B 2 O 7-Z (where A and B each represents a metal element, Z represents a number of 0 or more and 1 or less, A represents La, Pr, Nd, Sm, It contains at least one selected from the group consisting of Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Bi, Mn, and Y, and B is Ru, Zr, Sn, Hf, Ti, Ta , Nb, V, Sb and Ir at least one selected from the group consisting of Ir.) May be used.
本発明の他の態様は膜電極接合体である。当該膜電極接合体は、イオン伝導性を有する電解質膜と、前記電解質膜の一方の面に設けられているカソード触媒層と、前記電解質膜の一方の面に設けられているアノード触媒層と、を備え、前記カソード触媒層が上述したいずれかの態様の電極材料を備えることを特徴とする。 Another embodiment of the present invention is a membrane electrode assembly. The membrane electrode assembly includes an electrolyte membrane having ion conductivity, a cathode catalyst layer provided on one surface of the electrolyte membrane, an anode catalyst layer provided on one surface of the electrolyte membrane, And the cathode catalyst layer includes any one of the electrode materials described above.
本発明のさらに他の態様は燃料電池スタックである。当該燃料電池スタックは、上述した態様の膜電極接合体を備えることを特徴とする。 Yet another embodiment of the present invention is a fuel cell stack. The fuel cell stack includes the membrane electrode assembly according to the above-described aspect.
本発明のさらに他の態様は電極材料の製造方法である。当該電極材料の製造方法は、酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程と、前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程と、を含むことを特徴とする。 Yet another embodiment of the present invention is a method for producing an electrode material. The method for producing the electrode material includes a step of generating an electrode catalyst including metal oxide particles having activity for oxygen reduction, a step of covering at least a part of the surface of the metal oxide particles with a porous inorganic material, It is characterized by including.
上述した態様の電極材料の製造方法において、前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程の後に、さらに、前記多孔性無機材料の細孔表面を、塩基性官能基で修飾する工程を行ってもよい。前記塩基性官能基で修飾する工程が、前記多孔性無機材料と、有機シラン化合物とを反応させる工程であって、前記有機シラン化合物が、第一級アミノ基、第二級アミノ基、第三級アミノ基または第四級アンモニウム基のうち少なくとも１種以上を含んでもよい。 In the method for producing an electrode material according to the aspect described above, after the step of coating at least a part of the surface of the metal oxide particles with a porous inorganic material, the pore surface of the porous inorganic material is further treated with a basic functional group. A step of modifying with a group may be performed. The step of modifying with the basic functional group is a step of reacting the porous inorganic material with an organosilane compound, wherein the organosilane compound comprises a primary amino group, a secondary amino group, a third It may contain at least one of a quaternary amino group or a quaternary ammonium group.
なお、上述した各要素を適宜組み合わせたものも、本件特許出願によって特許による保護を求める発明の範囲に含まれうる。 A combination of the above-described elements as appropriate can also be included in the scope of the invention for which patent protection is sought by this patent application.
本発明によれば、燃料電池などに用いられる、金属酸化物系触媒の触媒活性及び耐久性を向上させることができる。 ADVANTAGE OF THE INVENTION According to this invention, the catalyst activity and durability of a metal oxide type catalyst used for a fuel cell etc. can be improved.
以下では、本発明の電極材料を固体高分子形燃料電池用カソード材料として用いる場合の一実施形態について、図面を参照しながら説明する。なお、本発明の電極材料の実施形態がこれによって何ら制限されるものではない。 Hereinafter, an embodiment in which the electrode material of the present invention is used as a cathode material for a polymer electrolyte fuel cell will be described with reference to the drawings. In addition, embodiment of the electrode material of this invention is not restrict | limited at all by this.
（１）電極材料
図１は、本発明の電極材料の一実施形態の構成を示す模式図である。同図に示すように、本実施形態の電極材料１０は、酸素還元活性を有する金属酸化物粒子１１と、金属酸化物粒子１１の一部を被覆する多孔性無機材料１２と、導電材１４と、から構成され、多孔性無機材料１２の細孔表面が塩基性官能基１３で修飾されているものである。また、主として、プロトン伝導性を有する電解質（イオノマー）１５が、上記電極材料１０に混合される。
(1) Electrode Material FIG. 1 is a schematic diagram showing the configuration of one embodiment of the electrode material of the present invention. As shown in the figure, the electrode material 10 of this embodiment includes a metal oxide particle 11 having oxygen reduction activity, a porous inorganic material 12 covering a part of the metal oxide particle 11, a conductive material 14, The pore surface of the porous inorganic material 12 is modified with a basic functional group 13. In addition, an electrolyte (ionomer) 15 having proton conductivity is mainly mixed with the electrode material 10.
以下に、これらの構成要素ごとに説明する。 Hereinafter, each of these components will be described.
（ｉ）金属酸化物粒子
固体高分子形燃料電池用カソード材料に用いられる金属酸化物粒子１１は、酸素還元反応に活性を有するものであれば特に制限はなく、公知の触媒が使用できる。具体的には、一般式Ａ２Ｂ２Ｏ７−Ｚで表されるパイロクロア型酸化物、あるいは、Ｔｉ，Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ、Ｓｒ、Ｙ、Ｚｒ、Ｎｂ、Ｍｏ、Ｒｕ、Ｒｈ、Ｓｎ、Ｓｂ、Ｂａ、Ｌａ、Ｃｅ、Ｈｆ、Ｔａ、Ｗ、Ｒｅ、Ｏｓ、Ｉｒ、Ｐｂ、Ｂｉのうち少なくとも１種以上の元素を含有する金属、金属炭化物、金属窒化物または金属炭窒化物の、酸化物または部分酸化物などが挙げられる。好ましくは、非Ｐｔ触媒としては高い酸素還元活性を有する、一般式Ａ２Ｂ２Ｏ７−Ｚ（ただし、ＡおよびＢはそれぞれ金属元素を表し、Ｚは０以上１以下の数を表し、ＡはＬａ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｐｂ、Ｂｉ、Ｍｎ、及びＹからなる群から選ばれる少なくとも一種を含み、ＢはＲｕ、Ｚｒ、Ｓｎ、Ｈｆ、Ｔｉ、Ｔａ、Ｎｂ、Ｖ、Ｓｂ、及びＩｒからなる群から選ばれる少なくとも一種を含む。）で表されるパイロクロア型酸化物が望ましい。
(I) Metal Oxide Particles The metal oxide particles 11 used for the cathode material for the polymer electrolyte fuel cell are not particularly limited as long as they are active in the oxygen reduction reaction, and known catalysts can be used. Specifically, a pyrochlore type oxide represented by the general formula A 2 B 2 O 7-Z , or Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Metal, metal carbide, metal containing at least one element of Nb, Mo, Ru, Rh, Sn, Sb, Ba, La, Ce, Hf, Ta, W, Re, Os, Ir, Pb, Bi Examples thereof include oxides or partial oxides of nitrides or metal carbonitrides. Preferably, the non-Pt catalyst has a high oxygen reduction activity and has a general formula A 2 B 2 O 7-Z (where A and B each represents a metal element, Z represents a number of 0 or more and 1 or less, and A Includes at least one selected from the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Bi, Mn, and Y, and B is Ru, A pyrochlore type oxide represented by Zr, Sn, Hf, Ti, Ta, Nb, V, Sb, and Ir is included.
金属酸化物粒子の平均粒子径は、小さいほど電気化学的に有効な表面積が大きくなり触媒活性が高くなる。従って、好ましくは１００ｎｍ以下、より好ましくは２０ｎｍ以下、最も好ましくは１０ｎｍ以下であることが望ましい。なお、本発明における活性触媒粒子の平均粒径は、Ｘ線回折におけるピークの半値幅あるいは透過電子顕微鏡像より見積もることができる。 The smaller the average particle diameter of the metal oxide particles, the larger the electrochemically effective surface area and the higher the catalytic activity. Therefore, it is desirable that the thickness is 100 nm or less, more preferably 20 nm or less, and most preferably 10 nm or less. In addition, the average particle diameter of the active catalyst particle in this invention can be estimated from the half width of the peak in a X-ray diffraction, or a transmission electron microscope image.
（ｉｉ）多孔性無機材料
多孔性無機材料１２は、固体高分子形燃料電池セル内の環境で安定であり、かつ、多孔性を有するものであればよい。具体的には、ＳｉＯ２、ＴｉＯ２、ＺｒＯ２、ＳｎＯ２などが使用できる。好ましくはＳｉＯ２を含むことが望ましい。ＳｉＯ２を含むことで、後述の塩基性官能基で、容易、かつ安定的に細孔表面を修飾することができるためである。
(Ii) Porous inorganic material The porous inorganic material 12 may be any material as long as it is stable in the environment inside the polymer electrolyte fuel cell and has porosity. Specifically, SiO 2, TiO 2, ZrO 2, etc. SnO 2 can be used. Preferably it is desirable to include SiO 2. This is because by including SiO 2 , the pore surface can be easily and stably modified with the basic functional group described later.
多孔性無機材料１２の平均被覆厚みは、０．５ｎｍ〜１００ｎｍであることが望ましく、より好ましくは１ｎｍ〜３０ｎｍ、さらに好ましくは２ｎｍ〜１０ｎｍが好ましい。多孔性無機材料１２の被覆厚みが０．５ｎｍより小さいと、強酸性のイオノマーが活性触媒粒子まで浸透し、十分な触媒活性及び耐久性が得られない。多孔性無機材料１２の被覆厚みが１００ｎｍより大きいと、電極反応に必要な電子伝導、イオン伝導またはガス拡散が阻害され、十分な発電性能が得られなくなる。なお、多孔性無機材料１２の被覆厚みは、透過電子顕微鏡像より見積もることができる。 The average coating thickness of the porous inorganic material 12 is desirably 0.5 nm to 100 nm, more preferably 1 nm to 30 nm, still more preferably 2 nm to 10 nm. When the coating thickness of the porous inorganic material 12 is smaller than 0.5 nm, the strongly acidic ionomer penetrates to the active catalyst particles, and sufficient catalytic activity and durability cannot be obtained. When the coating thickness of the porous inorganic material 12 is larger than 100 nm, electron conduction, ion conduction or gas diffusion necessary for the electrode reaction is hindered, and sufficient power generation performance cannot be obtained. In addition, the coating thickness of the porous inorganic material 12 can be estimated from a transmission electron microscope image.
多孔性無機材料１２の平均細孔径は、０．１ｎｍ〜１００ｎｍであることが望ましい。多孔性無機材料の平均細孔径が０．１ｎｍより小さいと、電極反応に必要なイオン伝導やガス拡散が阻害され、十分な発電性能が得られなくなる。多孔性無機材料１２の平均細孔径が１００ｎｍより大きいと、強酸性のイオノマーが細孔内部に浸透し、十分な触媒活性及び耐久性が得られない。 The average pore diameter of the porous inorganic material 12 is desirably 0.1 nm to 100 nm. If the average pore diameter of the porous inorganic material is smaller than 0.1 nm, ion conduction and gas diffusion necessary for the electrode reaction are hindered, and sufficient power generation performance cannot be obtained. If the average pore diameter of the porous inorganic material 12 is larger than 100 nm, the strongly acidic ionomer penetrates into the pores, and sufficient catalytic activity and durability cannot be obtained.
（ｉｉｉ）塩基性官能基
塩基性官能基１３は、所望の塩基性を有する官能基であればよい。具体的には、塩基性官能基１３として、窒素原子を含む有機官能基が挙げられる。塩基性官能基１３として、第一級アミン誘導体、第二級アミン誘導体、第三級アミン誘導体、第四級アンモニウム誘導体を用いることが好ましく、このうち、第四級アンモニウム誘導体を最も好ましく用いることができる。
(Iii) Basic Functional Group The basic functional group 13 may be a functional group having a desired basicity. Specifically, the basic functional group 13 includes an organic functional group containing a nitrogen atom. As the basic functional group 13, primary amine derivatives, secondary amine derivatives, tertiary amine derivatives, and quaternary ammonium derivatives are preferably used, and among these, quaternary ammonium derivatives are most preferably used. it can.
塩基性官能基１３の当量は、多孔性無機材料に対して０．０１ｍｅｑ／ｇ以上であることが望ましく、好ましくは０．１ｍｅｑ／ｇ以上、より好ましくは１ｍｅｑ／ｇ以上である。塩基性官能基１３の当量が多孔性無機材料に対して０．０１ｍｅｑ／ｇより小さいと、金属酸化物粒子近傍が十分に塩基性雰囲気にならず、十分な触媒活性及び耐久性が得られない場合がある。なお、塩基性官能基１３の当量は、熱重量分析より測定される塩基性官能基１３の質量より算出することができる。 The equivalent amount of the basic functional group 13 is desirably 0.01 meq / g or more, preferably 0.1 meq / g or more, more preferably 1 meq / g or more with respect to the porous inorganic material. When the equivalent of the basic functional group 13 is smaller than 0.01 meq / g with respect to the porous inorganic material, the vicinity of the metal oxide particles is not sufficiently basic atmosphere, and sufficient catalytic activity and durability cannot be obtained. There is a case. In addition, the equivalent of the basic functional group 13 can be calculated from the mass of the basic functional group 13 measured by thermogravimetric analysis.
（ｉｖ）導電材
導電材１４は、十分な導電性を有するものであれば特に制限はなく、公知のものが使用できる。具体的には、アセチレンブラック、ケッチェンブラック、フラーレン、カーボンナノチューブ、カーボンナノオニオンなどの導電性の炭素材料、酸化チタン、酸化スズなどの導電性金属酸化物、またはこれらの混合物が挙げられる。
(Iv) Conductive Material The conductive material 14 is not particularly limited as long as it has sufficient conductivity, and a known material can be used. Specifically, conductive carbon materials such as acetylene black, ketjen black, fullerene, carbon nanotube, and carbon nano-onion, conductive metal oxides such as titanium oxide and tin oxide, or a mixture thereof can be given.
導電材１４の混合比（導電材１４の質量／（金属酸化物粒子１１の質量＋導電材１４の質量））は、５〜９５％であることが好ましい。導電材１４の混合比が５％より低いと、カソード触媒層内の電子伝導パスが確保できず、十分な発電性能が得られなくなる。導電材１４の混合比が９５％より高いと、所望の質量の金属酸化物粒子１１を含むために必要なカソード触媒層の厚さが大きくなり、電極反応に必要なイオン伝導やガス拡散が阻害され、十分な発電性能が得られなくなる。 The mixing ratio of the conductive material 14 (the mass of the conductive material 14 / (the mass of the metal oxide particles 11 + the mass of the conductive material 14)) is preferably 5 to 95%. If the mixing ratio of the conductive material 14 is lower than 5%, an electron conduction path in the cathode catalyst layer cannot be secured, and sufficient power generation performance cannot be obtained. When the mixing ratio of the conductive material 14 is higher than 95%, the thickness of the cathode catalyst layer necessary for containing the metal oxide particles 11 having a desired mass increases, and ion conduction and gas diffusion necessary for the electrode reaction are hindered. As a result, sufficient power generation performance cannot be obtained.
（ｖ）イオノマー
イオノマー１５は、高いプロトン伝導性を有するものであれば特に制限はなく、公知のものが使用できる。好ましくは、上記高いプロトン伝導性に加えて、高いガス透過性、高い化学的耐久性を有するものが望ましい。具体的には、酸性官能基を有する、パーフルオロカーボン重合体、芳香族ポリエーテルエーテルケトン、またはポリスルホンなどが挙げられる。酸性官能基としては、スルホン酸、ホスホン酸、またはカルボン酸などが挙げられる。スルホン酸基を有するパーフルオロカーボン重合体の例として、ナフィオン（デュポン社製：登録商標）などが挙げられる。
(V) Ionomer The ionomer 15 is not particularly limited as long as it has high proton conductivity, and a known one can be used. Preferably, those having high gas permeability and high chemical durability in addition to the above high proton conductivity are desirable. Specific examples include perfluorocarbon polymers, aromatic polyetheretherketone, or polysulfone having an acidic functional group. Examples of the acidic functional group include sulfonic acid, phosphonic acid, and carboxylic acid. Examples of the perfluorocarbon polymer having a sulfonic acid group include Nafion (manufactured by DuPont: registered trademark).
イオノマー１５と金属酸化物粒子１１の混合比（イオノマー１５の質量／金属酸化物粒子１１の質量）は、特に制限されるものではなく、カソード触媒層において、電極反応に必要なプロトン伝導とガス拡散が良好になされる範囲で適宜決定すればよい。イオノマー１５と金属酸化物粒子１１の混合比は、好ましくは１％〜１０００％、より好ましくは５％〜１００％である。イオノマー１６と金属酸化物粒子１１の混合比が１％より低いと、電極反応に必要なプロトン伝導が良好になされず、十分な発電性能が得られない。イオノマー１５と金属酸化物粒子１１の混合比が１０００％より高いと、電極反応に必要なガス拡散が良好になされず、十分な発電性能が得られない。 The mixing ratio of ionomer 15 and metal oxide particles 11 (mass of ionomer 15 / mass of metal oxide particles 11) is not particularly limited, and proton conduction and gas diffusion necessary for electrode reaction in the cathode catalyst layer. What is necessary is just to determine suitably in the range by which is made favorable. The mixing ratio of the ionomer 15 and the metal oxide particles 11 is preferably 1% to 1000%, more preferably 5% to 100%. When the mixing ratio of the ionomer 16 and the metal oxide particles 11 is lower than 1%, the proton conduction necessary for the electrode reaction is not improved, and sufficient power generation performance cannot be obtained. When the mixing ratio of the ionomer 15 and the metal oxide particles 11 is higher than 1000%, gas diffusion necessary for the electrode reaction is not good, and sufficient power generation performance cannot be obtained.
このような構成とすることにより、金属酸化物粒子１１が酸性のイオノマー１５から隔離され、金属酸化物粒子近傍が塩基性雰囲気となる。これによって、金属酸化物粒子１１の触媒活性及び耐久性を向上させることができる。 By setting it as such a structure, the metal oxide particle 11 is isolated from the acidic ionomer 15, and the metal oxide particle vicinity becomes a basic atmosphere. Thereby, the catalytic activity and durability of the metal oxide particles 11 can be improved.
図２は、本発明の電極材料を、固体高分子形燃料電池用カソード材料として用いた場合における酸素還元反応の反応機構を示す模式図である。金属酸化物粒子近傍が塩基性雰囲気となるため、金属酸化物粒子表面においては、下記（３）式で表される酸素還元反応が起こる。また、酸性のイオノマーと塩基性の多孔性無機材料の細孔との界面では、下記（４）式で表される水の生成反応が起こる。下記（４）式で反応するＨ＋は、イオノマー及び電解質膜を通ってアノードから伝導される。また、下記（４）式で反応するＯＨ−は、多孔性無機材料の細孔内を通って金属酸化物粒子表面から伝導される。カソード全体としては、下記（３）式と下記（４）式とを合わせた下記（５）式で表される酸素還元反応が起こり、従来公知の固体高分子形燃料電池のカソード反応と同様になる。
Ｏ２＋２Ｈ２Ｏ＋４ｅ−→４ＯＨ−・・・（３）
Ｈ＋＋ＯＨ−→Ｈ２Ｏ・・・（４）
Ｏ２＋４Ｈ＋＋４ｅ−→２Ｈ２Ｏ・・・（５）
FIG. 2 is a schematic view showing a reaction mechanism of an oxygen reduction reaction when the electrode material of the present invention is used as a cathode material for a polymer electrolyte fuel cell. Since the vicinity of the metal oxide particles is a basic atmosphere, an oxygen reduction reaction represented by the following formula (3) occurs on the surface of the metal oxide particles. In addition, at the interface between the acidic ionomer and the pores of the basic porous inorganic material, a water generation reaction represented by the following formula (4) occurs. H + reacting in the following formula (4) is conducted from the anode through the ionomer and the electrolyte membrane. Further, OH − that reacts by the following formula (4) is conducted from the surface of the metal oxide particles through the pores of the porous inorganic material. The overall cathode undergoes an oxygen reduction reaction represented by the following formula (5), which is a combination of the following formula (3) and the following formula (4), and is similar to the cathode reaction of a conventionally known polymer electrolyte fuel cell. Become.
O 2 + 2H 2 O + 4e − → 4OH − (3)
H + + OH − → H 2 O (4)
O 2 + 4H + + 4e − → 2H 2 O (5)
（２）電極材料の製造方法
次に、本発明の電極材料の製造方法のうち、酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程と、前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程、及び、前記多孔性無機材料の細孔表面を、塩基性官能基で修飾する工程について説明する。
(2) Method for producing electrode material Next, in the method for producing an electrode material of the present invention, a step of producing an electrode catalyst containing metal oxide particles having activity for oxygen reduction, and a surface of the metal oxide particles The step of coating at least a part with a porous inorganic material and the step of modifying the pore surface of the porous inorganic material with a basic functional group will be described.
（ｉ）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程は、特に制限されるものではなく、公知の方法を用いることができる。酸素還元に活性を有する金属酸化物粒子の具体例は、既に説明した通りであるので、ここでの説明は省略する。以下、酸素還元に活性を有する金属酸化物粒子として、一般式Ａ２Ｂ２Ｏ７−Ｚ（ただし、ＡおよびＢはそれぞれ金属元素を表し、Ｚは０以上１以下の数を表し、ＡはＬａ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｐｂ、Ｂｉ、Ｍｎ、及びＹからなる群から選ばれる少なくとも一種を含み、ＢはＲｕ、Ｚｒ、Ｓｎ、Ｈｆ、Ｔｉ、Ｔａ、Ｎｂ、Ｖ、Ｓｂ、及びＩｒからなる群から選ばれる少なくとも一種を含む。）で表されるパイロクロア型酸化物を用いた場合につき、一例を説明する。
(I) The process of producing | generating the electrode catalyst containing the metal oxide particle which has activity in oxygen reduction The process of producing the electrode catalyst containing the metal oxide particle which has activity in oxygen reduction is not particularly limited, and is publicly known. This method can be used. Since the specific example of the metal oxide particle having activity for oxygen reduction is as already described, description thereof is omitted here. Hereinafter, as metal oxide particles having activity for oxygen reduction, general formula A 2 B 2 O 7-Z (where A and B each represents a metal element, Z represents a number of 0 or more and 1 or less, and A represents Including at least one selected from the group consisting of La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Bi, Mn, and Y, B is Ru, Zr , Sn, Hf, Ti, Ta, Nb, V, Sb, and Ir will be described.) An example will be described in the case of using a pyrochlore oxide represented by the following formula.
前記Ａのハロゲン化物または硝酸塩の水溶液である、第１の水溶液を用意する。前記Ａのハロゲン化物または硝酸塩の濃度については、特に制限されるものではないが、０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下であることが望ましい。第１の水溶液の温度については、特に制限されるものではないが、０℃以上６０℃以下であることが望ましい。 A first aqueous solution that is an aqueous solution of the halide or nitrate of A is prepared. The concentration of the halide or nitrate of A is not particularly limited, but is preferably 0.001 mol / L or more and 1 mol / L or less. The temperature of the first aqueous solution is not particularly limited, but is preferably 0 ° C. or higher and 60 ° C. or lower.
次に、前記Ｂの金属酸アルカリ水溶液である、第２の水溶液を用意する。前記Ｂの金属酸アルカリの濃度については、特に制限されるものではないが、０．００１ｍｏｌ／Ｌ以上１ｍｏｌ／Ｌ以下であることが望ましい。第２の水溶液の温度については、特に制限されるものではないが、０℃以上６０℃以下であることが望ましい。 Next, the 2nd aqueous solution which is the said B metal-acid alkali aqueous solution is prepared. The concentration of the B metal acid alkali is not particularly limited, but is preferably 0.001 mol / L or more and 1 mol / L or less. The temperature of the second aqueous solution is not particularly limited, but is preferably 0 ° C. or higher and 60 ° C. or lower.
次に、前記第１の水溶液および前記第２の水溶液のうちの一方を他方の中に滴下して、中和反応を行い、パイロクロア型酸化物の前駆体を生成させる。該中和反応の時間は、所望の中和反応を起こすのに十分であればよく、特に制限されるものではない。ここで、前記第１の水溶液および第２の水溶液のいずれか一方に、あらかじめ導電材を分散させてもよい。該導電材の具体例、および、導電材の混合比は、既に説明した通りであるので、ここでの説明は省略する。 Next, one of the first aqueous solution and the second aqueous solution is dropped into the other to perform a neutralization reaction, thereby generating a precursor of a pyrochlore oxide. The time for the neutralization reaction is not particularly limited as long as it is sufficient to cause a desired neutralization reaction. Here, a conductive material may be dispersed in advance in either one of the first aqueous solution and the second aqueous solution. The specific examples of the conductive material and the mixing ratio of the conductive materials are as described above, and thus the description thereof is omitted here.
その後、パイロクロア型酸化物の前駆体を洗浄、分離、乾燥し、最後に、焼成を行う。洗浄、分離、乾燥の方法は、特に制限されるものではなく、公知のものを利用できる。焼成時の雰囲気は、特に制限されるものではないが、不活性ガス雰囲気であることが望ましい。不活性ガスとしては、ヘリウム、窒素、アルゴンなどが挙げられる。焼成温度と焼成時間は、所望の結晶構造を形成するのに十分であればよく、特に制限されるものではないが、好ましくは、焼成温度が２５０℃以上９００℃以下、焼成時間が３０分以上１２０時間以下であることが望ましい。 Thereafter, the precursor of the pyrochlore type oxide is washed, separated and dried, and finally fired. The method of washing, separating and drying is not particularly limited, and known methods can be used. The atmosphere during firing is not particularly limited, but is preferably an inert gas atmosphere. Examples of the inert gas include helium, nitrogen, and argon. The firing temperature and firing time are not particularly limited as long as it is sufficient to form a desired crystal structure. Preferably, the firing temperature is 250 ° C. or higher and 900 ° C. or lower, and the firing time is 30 minutes or longer. It is desirable to be 120 hours or less.
（ｉｉ）金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程
金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程は、特に制限されるものではなく、公知の方法を用いることができる。以下、一例を説明する。
(Ii) Step of coating at least part of metal oxide particle surface with porous inorganic material The step of coating at least part of metal oxide particle surface with porous inorganic material is not particularly limited. A known method can be used. An example will be described below.
酸素還元に活性を有する金属酸化物粒子を含む電極触媒を、所定温度の溶媒に分散させる。該溶媒としては、水、エタノール、またはこれらの混合物などが挙げられるが、特に制限されるものではない。該温度についても、特に制限されるものではない。 An electrode catalyst containing metal oxide particles active in oxygen reduction is dispersed in a solvent at a predetermined temperature. Examples of the solvent include water, ethanol, and a mixture thereof, but are not particularly limited. The temperature is not particularly limited.
次に、ｐＨ調整剤を所定量添加する。該ｐＨ調整剤は、硝酸、アンモニア、トリエチルアミンなどが挙げられるが、特に制限されるものではない。 Next, a predetermined amount of a pH adjuster is added. Examples of the pH adjuster include nitric acid, ammonia, triethylamine and the like, but are not particularly limited.
次に、多孔性無機材料の前駆体１を添加し、所定時間攪拌する。多孔性無機材料の前駆体１は、加水分解−縮重合反応によりゲル化するものであればよい。具体的には、テトラエトキシシラン、メチルトリエトキシシラン、またはこれらの混合物などが挙げられる。
３−アミノプロピルトリエトキシシラン、３−（ジエチルアミノ）プロピルトリメトキシシランなどのアミノ基を有する有機シラン化合物、または、トリメチル［３−（トリエトキシシリル）プロピル］アンモニウムクロリドなどの４級アンモニウム基を有する有機シラン化合物を用いてもよい。攪拌時間は、所望の加水分解−縮重合反応を起こすのに十分であればよく、特に制限されるものではない。
Next, the porous inorganic material precursor 1 is added and stirred for a predetermined time. The porous inorganic material precursor 1 may be any material that gels by a hydrolysis-condensation polymerization reaction. Specific examples include tetraethoxysilane, methyltriethoxysilane, or a mixture thereof.
An organic silane compound having an amino group such as 3-aminopropyltriethoxysilane, 3- (diethylamino) propyltrimethoxysilane, or a quaternary ammonium group such as trimethyl [3- (triethoxysilyl) propyl] ammonium chloride. An organosilane compound may be used. The stirring time is not particularly limited as long as it is sufficient to cause a desired hydrolysis-condensation polymerization reaction.
上記工程の前に、多孔性無機材料の前駆体２を添加し、所定時間攪拌してもよい。多孔性無機材料の前駆体２は、金属酸化物粒子に選択的に吸着するものであればよい。具体的には、３−アミノプロピルトリエトキシシランなどが挙げられる。攪拌時間は、多孔性無機材料が粒子に選択的に吸着するのに十分な時間であればよく、特に制限されるものではない。 Prior to the above step, the precursor 2 of the porous inorganic material may be added and stirred for a predetermined time. The porous inorganic material precursor 2 may be any material that selectively adsorbs to the metal oxide particles. Specific examples include 3-aminopropyltriethoxysilane. The stirring time is not particularly limited as long as it is sufficient for the porous inorganic material to be selectively adsorbed on the particles.
その後、試料を洗浄、分離、乾燥し、最後に、焼成を行う。洗浄、分離、乾燥の方法は、特に制限されるものではなく、公知のものを利用できる。焼成時の雰囲気は、特に制限されるものではないが、電極材料の導電材にカーボン材料を含む場合は、酸化反応を防ぐために、不活性ガス雰囲気、還元性ガス雰囲気、またはこれらの混合ガス雰囲気であることが望ましい。不活性ガスとしては、ヘリウム、窒素、アルゴンなどが挙げられる。還元性ガスとしては、水素などが挙げられる。焼成温度と焼成時間は、所望の細孔構造が得られる範囲で適宜決定すればよい。多孔性無機材料の前駆体１として、３−アミノプロピルトリエトキシシラン、３−（ジエチルアミノ）プロピルトリメトキシシランなどのアミノ基を有する有機シラン化合物、または、トリメチル［３−（トリエトキシシリル）プロピル］アンモニウムクロリドなどの４級アンモニウム基を有する有機シラン化合物を用いた場合は、アミノ基や４級アンモニウム基が分解・燃焼しないような雰囲気・温度・時間で焼成を行うのが望ましい。 Thereafter, the sample is washed, separated, dried, and finally fired. The method of washing, separating and drying is not particularly limited, and known methods can be used. The atmosphere during firing is not particularly limited, but when the conductive material of the electrode material includes a carbon material, an inert gas atmosphere, a reducing gas atmosphere, or a mixed gas atmosphere thereof is used to prevent an oxidation reaction. It is desirable that Examples of the inert gas include helium, nitrogen, and argon. Examples of the reducing gas include hydrogen. The firing temperature and firing time may be appropriately determined within a range in which a desired pore structure can be obtained. As the porous inorganic material precursor 1, an organic silane compound having an amino group such as 3-aminopropyltriethoxysilane, 3- (diethylamino) propyltrimethoxysilane, or trimethyl [3- (triethoxysilyl) propyl] When an organic silane compound having a quaternary ammonium group such as ammonium chloride is used, it is desirable to perform firing in an atmosphere, temperature, and time so that the amino group or quaternary ammonium group does not decompose or burn.
（ｉｉ）多孔性無機材料の細孔表面を塩基性官能基で修飾する工程
多孔性無機材料の細孔表面を塩基性官能基で修飾する工程は、特に制限されるものではなく、公知の方法を用いることができる。具体的には、多孔性無機材料と、塩基性官能基と加水分解性基を有する有機シラン化合物とを、加水分解−縮重合反応により化学的に結合させる方法が挙げられる。以下、一例を説明する。
(Ii) Step of modifying the pore surface of the porous inorganic material with a basic functional group The step of modifying the pore surface of the porous inorganic material with a basic functional group is not particularly limited, and is a known method. Can be used. Specifically, a method of chemically bonding a porous inorganic material and an organic silane compound having a basic functional group and a hydrolyzable group by a hydrolysis-polycondensation reaction can be mentioned. An example will be described below.
前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程で得られた試料を、所定温度の溶媒に分散させる。該溶媒としては、水、エタノール、トルエン、またはこれらの混合物が挙げられるが、特に制限されるものではない。該温度についても、特に制限されるものではない。 A sample obtained in the step of coating at least a part of the surface of the metal oxide particles with a porous inorganic material is dispersed in a solvent at a predetermined temperature. Examples of the solvent include water, ethanol, toluene, and a mixture thereof, but are not particularly limited. The temperature is not particularly limited.
次に、塩基性官能基と加水分解性基を有する有機シラン化合物を添加し、所定時間攪拌する。塩基性官能基と加水分解性基を有する有機シラン化合物としては、３−アミノプロピルトリエトキシシラン、３−（２−アミノエチルアミノ）プロピルトリメトキシシラン、［３−（フェニルアミノ）プロピル］トリメトキシシラン、［３−（メチルアミノ）プロピル］トリメトキシシラン、３−（ジエチルアミノ）プロピルトリメトキシシラン、トリメチル［３−（トリエトキシシリル）プロピル］アンモニウムクロリドなどが挙げられる。攪拌時間は、多孔性無機材料と、塩基性官能基と加水分解性基を有する有機シラン化合物とが、所望の加水分解−縮重合反応を起こすのに十分であればよく、特に制限されるものではない。なお、塩基性官能基と加水分解性基を有する有機シラン化合物を添加する前に、所定量のｐＨ調整剤を添加してもよい。該ｐＨ調整剤は、硝酸、アンモニア、トリメチルアミンなどが挙げられるが、特に制限されるものではない。 Next, an organosilane compound having a basic functional group and a hydrolyzable group is added and stirred for a predetermined time. Examples of the organic silane compound having a basic functional group and a hydrolyzable group include 3-aminopropyltriethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, and [3- (phenylamino) propyl] trimethoxy. Examples include silane, [3- (methylamino) propyl] trimethoxysilane, 3- (diethylamino) propyltrimethoxysilane, trimethyl [3- (triethoxysilyl) propyl] ammonium chloride, and the like. The stirring time is not particularly limited as long as the porous inorganic material and the organic silane compound having a basic functional group and a hydrolyzable group are sufficient to cause a desired hydrolysis-condensation polymerization reaction. is not. In addition, you may add a predetermined amount of pH adjusters before adding the organosilane compound which has a basic functional group and a hydrolysable group. Examples of the pH adjuster include nitric acid, ammonia, trimethylamine and the like, but are not particularly limited.
その後、試料を洗浄、分離、乾燥する。洗浄、分離、乾燥の方法は、特に制限されるものではなく、公知のものを利用できる。 Thereafter, the sample is washed, separated, and dried. The method of washing, separating and drying is not particularly limited, and known methods can be used.
その後、適宜焼成を行ってもよい。焼成時の雰囲気は、特に制限されるものではないが、電極材料の導電材にカーボン材料を含む場合は、酸化反応を防ぐために、不活性ガス雰囲気、還元性ガス雰囲気、またはこれらの混合ガス雰囲気であることが望ましい。不活性ガスとしては、ヘリウム、窒素、アルゴンなどが挙げられる。還元性ガスとしては、水素などが挙げられる。焼成温度と焼成時間は、塩基性官能基が分解しない範囲で適宜決定すればよい。 Thereafter, firing may be performed as appropriate. The atmosphere during firing is not particularly limited, but when the conductive material of the electrode material includes a carbon material, an inert gas atmosphere, a reducing gas atmosphere, or a mixed gas atmosphere thereof is used to prevent an oxidation reaction. It is desirable that Examples of the inert gas include helium, nitrogen, and argon. Examples of the reducing gas include hydrogen. What is necessary is just to determine a calcination temperature and calcination time suitably in the range which a basic functional group does not decompose | disassemble.
なお、塩基性官能基と加水分解性基を有する有機シラン化合物として、第四級アンモニウム誘導体で、対イオンがヒドロキシイオン以外のものを用いた場合は、上記工程で得られた試料を塩基性水溶液中に浸漬し、対イオンをヒドロキシイオンに置換した後、純水で洗浄するのが望ましい。塩基性水溶液としては、水酸化カリウム水溶液、水酸化ナトリウム水溶液、アンモニア水などが挙げられるが、特に制限されるものではない。浸漬時間については、対イオンをヒドロキシイオンに置換するのに十分であればよく、特に制限されるものではない。 When the organic silane compound having a basic functional group and a hydrolyzable group is a quaternary ammonium derivative and the counter ion is other than a hydroxy ion, the sample obtained in the above step is a basic aqueous solution. It is desirable to immerse in and replace the counter ions with hydroxy ions, and then wash with pure water. Examples of the basic aqueous solution include a potassium hydroxide aqueous solution, a sodium hydroxide aqueous solution, and aqueous ammonia, but are not particularly limited. The immersion time is not particularly limited as long as it is sufficient to replace the counter ion with a hydroxy ion.
（３）燃料電池
次に、本発明の一実施形態に係る燃料電池について、図面を参照しながら説明する。
(3) Fuel Cell Next, a fuel cell according to an embodiment of the present invention will be described with reference to the drawings.
図３は、実施形態に係る燃料電池２０の構造を示す模式図である。燃料電池２０は、平板状の膜電極接合体２１を備え、この膜電極接合体２１の両側にはセパレータ２２ａおよびセパレータ２２ｂが設けられている。セパレータ２２ａやセパレータ２２ｂを介して複数の燃料電池２０が積層されることにより、燃料電池スタックを構成する積層体が形成される。 FIG. 3 is a schematic diagram showing the structure of the fuel cell 20 according to the embodiment. The fuel cell 20 includes a flat membrane electrode assembly 21, and a separator 22 a and a separator 22 b are provided on both sides of the membrane electrode assembly 21. By stacking a plurality of fuel cells 20 via the separator 22a and the separator 22b, a stacked body constituting the fuel cell stack is formed.
膜電極接合体２１は、電解質膜２３、アノード２４ａ、およびカソード２４ｂを有する。アノード２４ａは、アノード触媒層２５ａとアノードガス拡散層２６ａとからなる積層体を有する。一方、カソード２４ｂは、カソード触媒層２５ｂとカソードガス拡散層２６ｂとからなる積層体を有する。アノード触媒層２５ａとカソード触媒層２５ｂは、電解質膜２３を挟んで対向するように設けられている。アノードガス拡散層２６ａは、電解質膜２３とは反対側のアノード触媒層２５ａの面に設けられている。また、カソードガス拡散層２６ｂは、電解質膜２３とは反対側のカソード触媒層２５ｂの面に設けられている。 The membrane electrode assembly 21 includes an electrolyte membrane 23, an anode 24a, and a cathode 24b. The anode 24a has a laminate composed of an anode catalyst layer 25a and an anode gas diffusion layer 26a. On the other hand, the cathode 24b has a laminate composed of a cathode catalyst layer 25b and a cathode gas diffusion layer 26b. The anode catalyst layer 25a and the cathode catalyst layer 25b are provided to face each other with the electrolyte membrane 23 interposed therebetween. The anode gas diffusion layer 26 a is provided on the surface of the anode catalyst layer 25 a on the side opposite to the electrolyte membrane 23. The cathode gas diffusion layer 26 b is provided on the surface of the cathode catalyst layer 25 b opposite to the electrolyte membrane 23.
アノード２４ａ側に設けられるセパレータ２２ａにはガス流路２７ａが設けられている。燃料供給用のマニホールド（図示せず）から、水素、または水素を含む改質ガスがガス流路２７ａに分配され、ガス流路２７ａを通じて膜電極接合体２１に水素、または水素を含む改質ガスが供給される。同様に、カソード２４ｂ側に設けられるセパレータ２２ｂにはガス流路２７ｂが設けられている。酸化剤供給用のマニホールド（図示せず）から酸化剤として空気がガス流路２７ｂに分配され、ガス流路２７ｂを通じて膜電極接合体２１に空気が供給される。 The separator 22a provided on the anode 24a side is provided with a gas flow path 27a. Hydrogen or a reformed gas containing hydrogen is distributed to a gas flow path 27a from a fuel supply manifold (not shown), and the reformed gas containing hydrogen or hydrogen is supplied to the membrane electrode assembly 21 through the gas flow path 27a. Is supplied. Similarly, a gas flow path 27b is provided in the separator 22b provided on the cathode 24b side. Air as an oxidant is distributed to the gas flow path 27b from an oxidant supply manifold (not shown), and air is supplied to the membrane electrode assembly 21 through the gas flow path 27b.
以下に、これらの構成要素ごとに説明する。 Hereinafter, each of these components will be described.
（ｉ）電解質膜
電解質膜２３は、高いガス遮断性と高いプロトン伝導性を有するものであればよい。好ましくは、高いガス遮断性と高いプロトン伝導性に加えて、高い化学的・機械的耐久性を有するものが好ましい。具体的には、酸性官能基を有する、パーフルオロカーボン重合体、芳香族ポリエーテルエーテルケトン、またはポリスルホンなどが挙げられる。酸性官能基としては、スルホン酸、ホスホン酸、またはカルボン酸などが挙げられる。スルホン酸基を有するパーフルオロカーボン重合体の例として、ナフィオン（デュポン社製：登録商標）などが挙げられる。
(I) Electrolyte membrane The electrolyte membrane 23 should just have a high gas barrier property and a high proton conductivity. Preferably, those having high chemical and mechanical durability in addition to high gas barrier properties and high proton conductivity are preferred. Specific examples include perfluorocarbon polymers, aromatic polyetheretherketone, or polysulfone having an acidic functional group. Examples of the acidic functional group include sulfonic acid, phosphonic acid, and carboxylic acid. Examples of the perfluorocarbon polymer having a sulfonic acid group include Nafion (manufactured by DuPont: registered trademark).
電解質膜２３の膜厚は、５〜３００μｍであることが好ましい。電解質膜２３の膜厚が５μｍより薄いと、十分なガス遮断性と機械的耐久性が得られない。電解質膜２３の膜厚が３００μｍより厚いと、プロトン伝導抵抗が大きくなり、十分な発電性能が得られない。 The thickness of the electrolyte membrane 23 is preferably 5 to 300 μm. If the thickness of the electrolyte membrane 23 is thinner than 5 μm, sufficient gas barrier properties and mechanical durability cannot be obtained. If the thickness of the electrolyte membrane 23 is thicker than 300 μm, the proton conduction resistance increases and sufficient power generation performance cannot be obtained.
（ｉｉ）触媒層
本発明の一実施形態に係る燃料電池２０は、カソード触媒層２５ｂに、本発明の固体高分子形燃料電池用電極材料を備えることを特徴とするものである。
(Ii) Catalyst Layer The fuel cell 20 according to an embodiment of the present invention is characterized in that the cathode catalyst layer 25b includes the electrode material for a polymer electrolyte fuel cell of the present invention.
ここで用いられる本発明の固体高分子形燃料電池用電極材料については、既に説明した通りであるので、ここでの説明は省略する。 The electrode material for a polymer electrolyte fuel cell of the present invention used here is as already described, and therefore the description thereof is omitted here.
本発明の固体高分子形燃料電池用電極材料からなる触媒層の厚さは、好ましくは０．１〜１００μｍ、より好ましくは１〜５０μｍである。触媒層の厚さが０．１μｍより薄いと、含まれる電極材料の量が少ないため、十分な発電性能が得られない。触媒層の厚さが１００μｍより厚いと、電極反応に必要なプロトン伝導、ガス拡散が阻害され、十分な発電性能が得られない。 The thickness of the catalyst layer made of the electrode material for a polymer electrolyte fuel cell of the present invention is preferably 0.1 to 100 μm, more preferably 1 to 50 μm. When the thickness of the catalyst layer is less than 0.1 μm, the amount of the electrode material contained is small, so that sufficient power generation performance cannot be obtained. When the thickness of the catalyst layer is greater than 100 μm, proton conduction and gas diffusion necessary for the electrode reaction are hindered, and sufficient power generation performance cannot be obtained.
アノード触媒層２５ａには、公知の触媒層を用いることができる。アノード触媒層２５ａは、主として、導電性担体に金属粒子が担持された形態である電極触媒と、プロトン伝導性を有するイオノマーとで構成される。アノード触媒層２５ａの厚さは、本発明の高分子形燃料電池用電極材料からなる触媒層の厚さと同様の範囲でよい。 A known catalyst layer can be used for the anode catalyst layer 25a. The anode catalyst layer 25a is mainly composed of an electrode catalyst in which metal particles are supported on a conductive support and an ionomer having proton conductivity. The thickness of the anode catalyst layer 25a may be in the same range as the thickness of the catalyst layer made of the polymer fuel cell electrode material of the present invention.
（ｉｉｉ）ガス拡散層
ガス拡散層２６は、ガス拡散基材により形成される。ガス拡散基材は、電子伝導性を有する多孔体で構成であればよく、公知のものが使用でき、たとえば、金属板、金属フィルム、導電性高分子、カーボンペーパー、カーボンの織布または不織布などが挙げられる。
(Iii) Gas diffusion layer The gas diffusion layer 26 is formed of a gas diffusion base material. The gas diffusion base material may be composed of a porous body having electron conductivity, and a known material can be used. For example, a metal plate, a metal film, a conductive polymer, carbon paper, a carbon woven fabric or a non-woven fabric, etc. Is mentioned.
（ｉｖ）セパレータ
セパレータ２２は、高い導電性と高い耐腐食性を有していればよく、公知のものが使用できる。たとえば、炭素板等のカーボン材料、またはステンレスなどが挙げられる。
(Iv) Separator The separator 22 only needs to have high conductivity and high corrosion resistance, and a known one can be used. For example, a carbon material such as a carbon plate or stainless steel can be used.
以下に、本発明の電極材料の実施例について、詳細に説明する。ただし、本発明はこれら実施例に何ら限定されるものではない。 Below, the Example of the electrode material of this invention is described in detail. However, the present invention is not limited to these examples.
（実施例１）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
硝酸鉛（ＩＩ）（Ｐｂ（ＮＯ３）２）を純水に溶解した０．１ｍｏｌ／Ｌの硝酸鉛（ＩＩ）水溶液へ、ルテニウム酸カリウム（Ｋ２ＲｕＯ４）を純水に溶解した０．１ｍｏｌ／Ｌのルテニウム酸カリウム水溶液を、ＰｂとＲｕのモル比が１：１となるよう滴下し、１時間攪拌した。その後、生成したパイロクロア型酸化物の前駆体を濾別し、純水で洗浄し、真空（１００ｔｏｒｒ）下８０℃で８時間乾燥させた。その後、得られた試料を、窒素流通下３５０℃で６時間熱処理を行った。得られた試料を、以下、Ｐｂ２Ｒｕ２Ｏ７−ｚと記す。
Example 1
(1) A step of producing an electrode catalyst containing metal oxide particles having activity in oxygen reduction 0.1 mol / L lead nitrate (II) in which lead (II) nitrate (Pb (NO 3 ) 2 ) is dissolved in pure water ) A 0.1 mol / L potassium ruthenate aqueous solution prepared by dissolving potassium ruthenate (K 2 RuO 4 ) in pure water was added dropwise to the aqueous solution so that the molar ratio of Pb and Ru was 1: 1, and the mixture was stirred for 1 hour. did. Then, the produced pyrochlore type oxide precursor was filtered off, washed with pure water, and dried at 80 ° C. under vacuum (100 torr) for 8 hours. Thereafter, the obtained sample was heat-treated at 350 ° C. for 6 hours under a nitrogen flow. The obtained sample is hereinafter referred to as Pb 2 Ru 2 O 7-z .
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
上記工程で得たＰｂ２Ｒｕ２Ｏ７−ｚを純水中に分散させ、６０℃で５分間超音波処理を行った。次に、トリエチルアミンで溶液のｐＨを約１０にし、３−アミノプロピルトリエトキシシランを添加し、６０℃で３０分間攪拌した。次に、テトラエトキシシランを添加し、６０℃で１８０分間攪拌した。その後、遠心分離により試料を回収し、６０℃で一晩乾燥させた。得られた試料を窒素流通下、３５０℃で２時間熱処理を行った。得られた試料を、以下、ＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚと記す。透過電子顕微鏡より、Ｐｂ２Ｒｕ２Ｏ７−ｚがＳｉＯ２で被覆されていることが確認できた。また、平均被覆厚みは約４ｎｍと見積もられた（図４参照）。
(2) Step of coating a part of metal oxide particles with a porous inorganic material Pb 2 Ru 2 O 7-z obtained in the above step is dispersed in pure water and subjected to ultrasonic treatment at 60 ° C. for 5 minutes. It was. Next, the pH of the solution was adjusted to about 10 with triethylamine, 3-aminopropyltriethoxysilane was added, and the mixture was stirred at 60 ° C. for 30 minutes. Next, tetraethoxysilane was added and stirred at 60 ° C. for 180 minutes. Thereafter, the sample was collected by centrifugation and dried at 60 ° C. overnight. The obtained sample was heat-treated at 350 ° C. for 2 hours under nitrogen flow. The obtained sample is hereinafter referred to as SiO 2 / Pb 2 Ru 2 O 7-z . From the transmission electron microscope, it was confirmed that Pb 2 Ru 2 O 7-z was coated with SiO 2 . The average coating thickness was estimated to be about 4 nm (see FIG. 4).
（実施例２）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｐｂ２Ｒｕ２Ｏ７−ｚを得た。
(Example 2)
(1) Step of generating an electrode catalyst containing metal oxide particles having activity in oxygen reduction According to the step of Example 1 (1), Pb 2 Ru 2 O 7-z was obtained.
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
実施例１（２）の工程に準じ、ＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚを得た。
(2) according to process step Example 1 (2) covering a portion of the metal oxide particles in the porous inorganic material to obtain a SiO 2 / Pb 2 Ru 2 O 7-z.
（３）多孔性無機材料の細孔表面を塩基性官能基で修飾する工程
上記工程で得たＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚをトルエン中に分散させ、室温で５分間超音波処理を行った。次に、３−アミノプロピルテトラエトキシシランを添加し、室温で１２０分間攪拌した。その後、遠心分離により試料を回収し、メタノール／水（メタノール：８０ｖｏｌ％）中に分散させて、室温で３０分間攪拌し、洗浄を行った。その後、再び遠心分離により試料を回収し、１２０℃で一晩乾燥した。これにより、ＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚのＳｉＯ２細孔表面が、アミノプロピル基（ＡＰ）で修飾された電極材料を得た。熱重量分析より、ＳｉＯ２に対するアミノプロピル基（ＡＰ）の当量は、３．５ｍｅｑ／ｇと測定された。
(3) Step of modifying porous surface of porous inorganic material with basic functional group SiO 2 / Pb 2 Ru 2 O 7-z obtained in the above step is dispersed in toluene and subjected to ultrasonic treatment at room temperature for 5 minutes. Went. Next, 3-aminopropyltetraethoxysilane was added and stirred at room temperature for 120 minutes. Thereafter, the sample was collected by centrifugation, dispersed in methanol / water (methanol: 80 vol%), stirred for 30 minutes at room temperature, and washed. Thereafter, the sample was again collected by centrifugation and dried at 120 ° C. overnight. Thereby, an electrode material in which the SiO 2 pore surface of SiO 2 / Pb 2 Ru 2 O 7-z was modified with an aminopropyl group (AP) was obtained. From thermogravimetric analysis, the equivalent of aminopropyl group (AP) to SiO 2 was determined to be 3.5 meq / g.
（実施例３）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｐｂ２Ｒｕ２Ｏ７−ｚを得た。
(Example 3)
(1) Step of generating an electrode catalyst containing metal oxide particles having activity in oxygen reduction According to the step of Example 1 (1), Pb 2 Ru 2 O 7-z was obtained.
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
実施例１（２）の工程に準じ、ＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚを得た。
(2) according to process step Example 1 (2) covering a portion of the metal oxide particles in the porous inorganic material to obtain a SiO 2 / Pb 2 Ru 2 O 7-z.
（３）多孔性無機材料の細孔表面を塩基性官能基で修飾する工程
上記工程で得たＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚをトルエン中に分散させ、室温で５分間超音波処理を行った。次に、トリメチル［３−（トリエトキシシリル）プロピル］アンモニウムクロリド（５０ｗｔ％メタノール溶液）を添加し、室温で１２０分間攪拌した。その後、遠心分離により試料を回収し、メタノール／水（メタノール：８０ｖｏｌ％）中に分散させて、室温で３０分間攪拌し、洗浄を行った。その後、再び遠心分離により試料を回収し、１２０℃で一晩乾燥した。得られた試料をＫＯＨ水溶液（ＫＯＨ：１０ｍＭ）中に分散させ、室温で１２０分間攪拌し、第四級アンモニウム基の対イオンをヒドロキシイオンに置換した。その後、遠心分離により試料を回収し、純水中に分散させ、室温で１２０分間攪拌し、洗浄を行った。同様の洗浄をさらに２回繰り返した後、遠心分離で試料を回収し、１２０℃で一晩乾燥した。これにより、ＳｉＯ２／Ｐｂ２Ｒｕ２Ｏ７−ｚのＳｉＯ２細孔表面が、トリメチルヒドロキシプロピルアンモニウム基（ＴＭＰＡ）で修飾された電極材料を得た。熱重量分析より、ＳｉＯ２に対するトリメチルヒドロキシプロピルアンモニウム基（ＴＭＰＡ）の当量は、３．３ｍｅｑ／ｇと測定された。
(3) Step of modifying porous surface of porous inorganic material with basic functional group SiO 2 / Pb 2 Ru 2 O 7-z obtained in the above step is dispersed in toluene and subjected to ultrasonic treatment at room temperature for 5 minutes. Went. Next, trimethyl [3- (triethoxysilyl) propyl] ammonium chloride (50 wt% methanol solution) was added and stirred at room temperature for 120 minutes. Thereafter, the sample was collected by centrifugation, dispersed in methanol / water (methanol: 80 vol%), stirred for 30 minutes at room temperature, and washed. Thereafter, the sample was again collected by centrifugation and dried at 120 ° C. overnight. The obtained sample was dispersed in an aqueous KOH solution (KOH: 10 mM) and stirred at room temperature for 120 minutes to replace the counter ion of the quaternary ammonium group with a hydroxy ion. Thereafter, the sample was collected by centrifugation, dispersed in pure water, stirred at room temperature for 120 minutes, and washed. The same washing was repeated twice more, and then the sample was collected by centrifugation and dried at 120 ° C. overnight. Thus, an electrode material in which the SiO 2 pore surface of SiO 2 / Pb 2 Ru 2 O 7-z was modified with a trimethylhydroxypropylammonium group (TMPA) was obtained. From the thermogravimetric analysis, the equivalent of trimethylhydroxypropylammonium group (TMPA) to SiO 2 was determined to be 3.3 meq / g.
（比較例１）
（１）酸素還元に活性を有する金属酸化物を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｐｂ２Ｒｕ２Ｏ７−ｚを得た。
(Comparative Example 1)
(1) Step of generating an electrode catalyst containing a metal oxide having activity in oxygen reduction According to the step of Example 1 (1), Pb 2 Ru 2 O 7-z was obtained.
（実施例４）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
Ｚｒフタロシアニンを低酸素分圧下、９００℃で６時間熱処理を行った。得られた試料を、以下、Ｚｒ−ＣＮＯと記す。
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
上記工程で得たＺｒ−ＣＮＯを純水中に分散させ、６０℃で５分間超音波処理を行った。次に、トリエチルアミンで溶液のｐＨを約１０にし、３−アミノプロピルトリエトキシシランを添加し、６０℃で３０分間攪拌した。次に、テトラエトキシシランを添加し、６０℃で１８０分間攪拌した。その後、遠心分離により試料を回収し、６０℃で一晩乾燥させた。得られた試料を窒素流通下、３５０℃で２時間熱処理を行った。得られた試料を、以下、ＳｉＯ２／Ｚｒ−ＣＮＯと記す。
Example 4
(1) Step of producing an electrode catalyst containing metal oxide particles having activity in oxygen reduction Zr phthalocyanine was heat-treated at 900 ° C. for 6 hours under a low oxygen partial pressure. The obtained sample is hereinafter referred to as Zr-CNO.
(2) Step of coating a part of metal oxide particles with a porous inorganic material Zr—CNO obtained in the above step was dispersed in pure water and sonicated at 60 ° C. for 5 minutes. Next, the pH of the solution was adjusted to about 10 with triethylamine, 3-aminopropyltriethoxysilane was added, and the mixture was stirred at 60 ° C. for 30 minutes. Next, tetraethoxysilane was added and stirred at 60 ° C. for 180 minutes. Thereafter, the sample was collected by centrifugation and dried at 60 ° C. overnight. The obtained sample was heat-treated at 350 ° C. for 2 hours under nitrogen flow. The obtained sample is hereinafter referred to as SiO 2 / Zr—CNO.
（実施例５）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｚｒ−ＣＮＯを得た。
(Example 5)
(1) Step of generating an electrode catalyst containing metal oxide particles having activity in oxygen reduction According to the step of Example 1 (1), Zr-CNO was obtained.
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
実施例１（２）の工程に準じ、ＳｉＯ２／Ｚｒ−ＣＮＯを得た。
(2) according to process step Example 1 (2) covering a portion of the metal oxide particles in the porous inorganic material to obtain a SiO 2 / Zr-CNO.
（３）多孔性無機材料の細孔表面を塩基性官能基で修飾する工程
上記工程で得たＳｉＯ２／Ｚｒ−ＣＮＯをトルエン中に分散させ、室温で５分間超音波処理を行った。次に、３−アミノプロピルテトラエトキシシランを添加し、室温で１２０分間攪拌した。その後、遠心分離により試料を回収し、メタノール／水（メタノール：８０ｖｏｌ％）中に分散させて、室温で３０分間攪拌し、洗浄を行った。その後、再び遠心分離により試料を回収し、１２０℃で一晩乾燥した。これにより、ＳｉＯ２／Ｚｒ−ＣＮＯのＳｉＯ２細孔表面が、アミノプロピル基（ＡＰ）で修飾された電極材料を得た。熱重量分析より、ＳｉＯ２に対するアミノプロピル基（ＡＰ）の当量は、３．５ｍｅｑ／ｇと測定された。
(3) Step of modifying pore surface of porous inorganic material with basic functional group SiO 2 / Zr—CNO obtained in the above step was dispersed in toluene and sonicated for 5 minutes at room temperature. Next, 3-aminopropyltetraethoxysilane was added and stirred at room temperature for 120 minutes. Thereafter, the sample was collected by centrifugation, dispersed in methanol / water (methanol: 80 vol%), stirred for 30 minutes at room temperature, and washed. Thereafter, the sample was again collected by centrifugation and dried at 120 ° C. overnight. As a result, an electrode material in which the SiO 2 pore surface of SiO 2 / Zr—CNO was modified with an aminopropyl group (AP) was obtained. From thermogravimetric analysis, the equivalent of aminopropyl group (AP) to SiO 2 was determined to be 3.5 meq / g.
（実施例６）
（１）酸素還元に活性を有する金属酸化物粒子を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｚｒ−ＣＮＯを得た。
(Example 6)
(1) Step of generating an electrode catalyst containing metal oxide particles having activity in oxygen reduction According to the step of Example 1 (1), Zr-CNO was obtained.
（２）金属酸化物粒子の一部を多孔性無機材料で被覆する工程
実施例１（２）の工程に準じ、ＳｉＯ２／ＰＺｒ−ＣＮＯを得た。
(2) Step of coating part of metal oxide particles with porous inorganic material According to the step of Example 1 (2), SiO 2 / PZr-CNO was obtained.
（３）多孔性無機材料の細孔表面を塩基性官能基で修飾する工程
上記工程で得たＳｉＯ２／Ｚｒ−ＣＮＯをトルエン中に分散させ、室温で５分間超音波処理を行った。次に、トリメチル［３−（トリエトキシシリル）プロピル］アンモニウムクロリド（５０ｗｔ％メタノール溶液）を添加し、室温で１２０分間攪拌した。その後、遠心分離により試料を回収し、メタノール／水（メタノール：８０ｖｏｌ％）中に分散させて、室温で３０分間攪拌し、洗浄を行った。その後、再び遠心分離により試料を回収し、１２０℃で一晩乾燥した。得られた試料をＫＯＨ水溶液（ＫＯＨ：１０ｍＭ）中に分散させ、室温で１２０分間攪拌し、第四級アンモニウム基の対イオンをヒドロキシイオンに置換した。その後、遠心分離により試料を回収し、純水中に分散させ、室温で１２０分間攪拌し、洗浄を行った。同様の洗浄をさらに２回繰り返した後、遠心分離で試料を回収し、１２０℃で一晩乾燥した。これにより、ＳｉＯ２／Ｚｒ−ＣＮＯのＳｉＯ２細孔表面が、トリメチルヒドロキシプロピルアンモニウム基（ＴＭＰＡ）で修飾された電極材料を得た。熱重量分析より、ＳｉＯ２に対するトリメチルヒドロキシプロピルアンモニウム基（ＴＭＰＡ）の当量は、３．４ｍｅｑ／ｇと測定された。
(3) Step of modifying pore surface of porous inorganic material with basic functional group SiO 2 / Zr—CNO obtained in the above step was dispersed in toluene and sonicated for 5 minutes at room temperature. Next, trimethyl [3- (triethoxysilyl) propyl] ammonium chloride (50 wt% methanol solution) was added and stirred at room temperature for 120 minutes. Thereafter, the sample was collected by centrifugation, dispersed in methanol / water (methanol: 80 vol%), stirred for 30 minutes at room temperature, and washed. Thereafter, the sample was again collected by centrifugation and dried at 120 ° C. overnight. The obtained sample was dispersed in an aqueous KOH solution (KOH: 10 mM) and stirred at room temperature for 120 minutes to replace the counter ion of the quaternary ammonium group with a hydroxy ion. Thereafter, the sample was collected by centrifugation, dispersed in pure water, stirred at room temperature for 120 minutes, and washed. The same washing was repeated twice more, and then the sample was collected by centrifugation and dried at 120 ° C. overnight. Thus, an electrode material in which the SiO 2 pore surface of SiO 2 / Zr—CNO was modified with a trimethylhydroxypropylammonium group (TMPA) was obtained. From the thermogravimetric analysis, the equivalent of trimethylhydroxypropylammonium group (TMPA) to SiO 2 was determined to be 3.4 meq / g.
（比較例２）
（１）酸素還元に活性を有する金属酸化物を含む電極触媒を生成する工程
実施例１（１）の工程に準じ、Ｚｒ−ＣＮＯを得た。
(Comparative Example 2)
(1) Step of generating an electrode catalyst containing a metal oxide having activity in oxygen reduction According to the step of Example 1 (1), Zr-CNO was obtained.
＜カソード触媒スラリーの作製＞
実施例１〜６及び比較例１、２で得られた各電極材料につき、それぞれ、２０ｗｔ％Ｎａｆｉｏｎ溶液（デュポン社製：登録商標）、カーボンブラック、水、及び１−プロパノールの混合溶液中に分散させ、室温で６０分間超音波処理を行い、カソード触媒スラリーを作製した。ここで、各カソード触媒スラリーは、総体積が５０ｍｌ、水と１−プロパノールの体積比が水／プロパノール＝１／４、含まれるＰｂ２Ｒｕ２Ｏ７−ｚまたはＺｒ−ＣＮＯが０．５ｇ、Ｐｂ２Ｒｕ２Ｏ７−ｚまたはＺｒ−ＣＮＯに対するＮａｆｉｏｎの質量比が１．０、Ｐｂ２Ｒｕ２Ｏ７−ｚまたはＺｒ−ＣＮＯに対するカーボンブラックの質量比が１．０となるようにした。
<Preparation of cathode catalyst slurry>
Each electrode material obtained in Examples 1 to 6 and Comparative Examples 1 and 2 was dispersed in a mixed solution of 20 wt% Nafion solution (manufactured by DuPont: registered trademark), carbon black, water, and 1-propanol. Then, ultrasonic treatment was performed at room temperature for 60 minutes to prepare a cathode catalyst slurry. Here, each cathode catalyst slurry has a total volume of 50 ml, a volume ratio of water to 1-propanol of water / propanol = 1/4, 0.5 g of Pb 2 Ru 2 O 7-z or Zr—CNO contained, the weight ratio of Nafion for Pb 2 Ru 2 O 7-z or Zr-CNO is 1.0, as the mass ratio of carbon black is 1.0 for Pb 2 Ru 2 O 7-z or Zr-CNO.
＜カソードの作製＞
面積５ｃｍ２のガス拡散基材（カーボンペーパー）に、上記カソード触媒スラリーを塗布してカソード触媒層を形成した後、一晩乾燥させた。なお、それぞれＰｂ２Ｒｕ２Ｏ７−ｚまたはＺｒ−ＣＮＯの量が０．５ｍｇ／ｃｍ２となるようにした。
<Production of cathode>
The cathode catalyst slurry was applied to a gas diffusion substrate (carbon paper) having an area of 5 cm 2 to form a cathode catalyst layer, and then dried overnight. Note that the amount of Pb 2 Ru 2 O 7-z or Zr—CNO was 0.5 mg / cm 2 , respectively.
＜アノード触媒スラリーの作製＞
白金担持カーボンブラック（ＴＥＣ１０Ｅ５０Ｅ、田中貴金属工業株式会社）を、２０ｗｔ％Ｎａｆｉｏｎ溶液（デュポン社製：登録商標）、水、及び１−プロパノールの混合溶液中に分散させ、室温で６０分間超音波処理を行い、カソード触媒スラリーを作製した。ここで、各カソード触媒スラリーは、総体積が５０ｍｌ、水と１−プロパノールの体積比が水／プロパノール＝１／４、含まれる白金が０．５ｇ、白金に対するＮａｆｉｏｎの質量比が１．０、となるようにした。
<Preparation of anode catalyst slurry>
Platinum-supported carbon black (TEC10E50E, Tanaka Kikinzoku Kogyo Co., Ltd.) is dispersed in a mixed solution of 20 wt% Nafion solution (manufactured by DuPont: registered trademark), water, and 1-propanol, and subjected to ultrasonic treatment at room temperature for 60 minutes. To produce a cathode catalyst slurry. Here, each cathode catalyst slurry has a total volume of 50 ml, the volume ratio of water to 1-propanol is water / propanol = 1/4, the contained platinum is 0.5 g, and the mass ratio of Nafion to platinum is 1.0. It was made to become.
＜アノードの作製＞
面積５ｃｍ２のガス拡散基材（カーボンペーパー）に、上記アノード触媒スラリーを塗布してアノード触媒層を形成した後、一晩乾燥させた。なお、それぞれ白金の量が０．５ｍｇ／ｃｍ２となるようにした。
<Production of anode>
The anode catalyst slurry was applied to a gas diffusion substrate (carbon paper) having an area of 5 cm 2 to form an anode catalyst layer, and then dried overnight. The amount of platinum was set to 0.5 mg / cm 2 respectively.
＜膜電極接合体の作製＞
上記アノードと上記カソードとの間に電解質膜を狭持した状態でホットプレスを行い、膜電極接合体を作製した。ここで、電解質膜としてＮａｆｉｏｎ２１２（デュポン社製：登録商標）を用いた。また、ホットプレスの条件は、１２０℃、５ＭＰａ、１６０秒とした。
<Preparation of membrane electrode assembly>
Hot pressing was performed with the electrolyte membrane sandwiched between the anode and the cathode to produce a membrane electrode assembly. Here, Nafion 212 (manufactured by DuPont: registered trademark) was used as the electrolyte membrane. The hot pressing conditions were 120 ° C., 5 MPa, and 160 seconds.
＜燃料電池の作製＞
上記膜電極接合体のアノード面、カソード面に、それぞれ、燃料流路が設けられたセパレータ、酸化剤流路が設けられたセパレータを配設し、燃料電池を作製した。電極の有効面積は５ｃｍ２で、燃料流路及び酸化剤流路は、ともに１流路のサーペンタイン型流路であり、燃料流路および酸化剤流路は並行流とした。
<Fabrication of fuel cell>
A separator provided with a fuel flow channel and a separator provided with an oxidant flow channel were disposed on the anode surface and the cathode surface of the membrane electrode assembly, respectively, to produce a fuel cell. The effective area of the electrode was 5 cm 2 , the fuel flow path and the oxidant flow path were both serpentine flow paths, and the fuel flow path and the oxidant flow path were parallel flow.
＜発電試験＞
実施例１〜６及び比較例１、２の燃料電池について、それぞれ下記条件で発電試験を行った。発電試験は、初期及び後述の電位サイクル試験後に行った。
アノードガス：Ｈ２、流量１００ｍｌ／ｍｉｎ
カソードガス：Ｏ２、流量１００ｍｌ／ｍｉｎ
セル温度：７０℃
アノードガス用バブラー温度：７０℃
カソードガス用バブラー温度：７０℃
<Power generation test>
About the fuel cell of Examples 1-6 and Comparative Examples 1 and 2, the electric power generation test was done on the following conditions, respectively. The power generation test was conducted at the initial stage and after the potential cycle test described later.
Anode gas: H 2 , flow rate 100 ml / min
Cathode gas: O 2 , flow rate 100 ml / min
Cell temperature: 70 ° C
Bubbler temperature for anode gas: 70 ° C
Bubbler temperature for cathode gas: 70 ° C
＜電位サイクル試験＞
実施例１〜６及び比較例１、２の燃料電池について、劣化加速試験として、それぞれ下記条件で電位サイクル試験を行った。
アノードガス：Ｈ２、流量１００ｍｌ／ｍｉｎ
カソードガス：Ｎ２、流量１００ｍｌ／ｍｉｎ
セル温度：７０℃
アノードガス用バブラー温度：７０℃
カソードガス用バブラー温度：７０℃
電位走査範囲：０．０５Ｖ〜１．２Ｖ（ｖｓ ＲＨＥ）
電位走査速度：０．５Ｖ／ｓ
電位サイクル数：１００００回
<Potential cycle test>
About the fuel cell of Examples 1-6 and Comparative Examples 1 and 2, as a deterioration acceleration test, the electric potential cycle test was done on the following conditions, respectively.
Anode gas: H 2 , flow rate 100 ml / min
Cathode gas: N 2 , flow rate 100 ml / min
Cell temperature: 70 ° C
Bubbler temperature for anode gas: 70 ° C
Bubbler temperature for cathode gas: 70 ° C
Potential scanning range: 0.05 V to 1.2 V (vs RHE)
Potential scanning speed: 0.5 V / s
Number of potential cycles: 10,000
実施例３及び比較例１の燃料電池について、初期及び電位サイクル試験後の発電試験結果を図５に示す。初期において、実施例３の燃料電池は、比較例１の燃料電池よりも著しく高い発電性能を示した。また、比較例１の燃料電池は、電位サイクル試験後に発電性能の低下が見られたのに対し、実施例３の燃料電池は、電位サイクル試験後も初期とほぼ同等の発電性能を示した。 About the fuel cell of Example 3 and Comparative Example 1, the electric power generation test result after an initial stage and a potential cycle test is shown in FIG. In the initial stage, the fuel cell of Example 3 showed significantly higher power generation performance than the fuel cell of Comparative Example 1. In addition, the fuel cell of Comparative Example 1 showed a decrease in power generation performance after the potential cycle test, whereas the fuel cell of Example 3 showed almost the same power generation performance as the initial state after the potential cycle test.
実施例１〜６及び比較例１〜２の燃料電池について、それぞれ、初期における３００ｍＡ／ｃｍ２発電時の電圧、電位サイクル後の電圧の低下量を表１に示す。
以上から、酸素還元に活性を有する金属酸化物粒子を含む電極触媒において、金属酸化物粒子の表面を多孔性無機材料で被覆し、さらに、多孔性無機材料の細孔表面を塩基性官能基で修飾することで、金属酸化物粒子の触媒活性及び耐久性を著しく向上させ、従来よりも高い発電性能及び耐久性が得られることがわかった。 From the above, in the electrode catalyst including metal oxide particles having activity for oxygen reduction, the surface of the metal oxide particles is coated with a porous inorganic material, and the pore surface of the porous inorganic material is covered with a basic functional group. It has been found that the modification significantly improves the catalytic activity and durability of the metal oxide particles, and provides higher power generation performance and durability than before.
本発明は、上記実施の形態に限定されるものではなく、当業者の知識に基づいて各種の設計変更等の変形を加えることも可能であり、そのような変形が加えられた実施の形態も本発明の範囲に含まれ得るものである。 The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art, and the embodiments to which such modifications are added are also possible. It can be included in the scope of the present invention.
１０ 電極材料、１１ 金属酸化物粒子、１２ 多孔性無機材料、１３ 塩基性官能基、１４ 導電材、１５ 電解質、２０ 燃料電池、２１ 膜電極接合体、２２ａ，２２ｂ セパレータ、２３ 電解質膜、２４ａ アノード、２４ｂ カソード、２５ａ アノード触媒層、２６ａ アノードガス拡散層、２５ｂ カソード触媒層、２６ｂ カソードガス拡散層 DESCRIPTION OF SYMBOLS 10 Electrode material, 11 Metal oxide particle, 12 Porous inorganic material, 13 Basic functional group, 14 Conductive material, 15 Electrolyte, 20 Fuel cell, 21 Membrane electrode assembly, 22a, 22b Separator, 23 Electrolyte membrane, 24a Anode 24b cathode, 25a anode catalyst layer, 26a anode gas diffusion layer, 25b cathode catalyst layer, 26b cathode gas diffusion layer
Claims (9)
前記金属酸化物粒子の表面の少なくとも一部を被覆する多孔性無機材料と、を備え、
前記多孔性無機材料の細孔表面が塩基性官能基で修飾されていることを特徴とする電極材料。 An electrocatalyst comprising metal oxide particles active in oxygen reduction;
A porous inorganic material covering at least a part of the surface of the metal oxide particles ,
Electrode material pore surfaces of the porous inorganic material is characterized that you have been modified with basic functional groups.
（ただし、ＡおよびＢはそれぞれ金属元素を表し、Ｚは０以上１以下の数を表し、ＡはＬａ、Ｐｒ、Ｎｄ、Ｓｍ、Ｅｕ、Ｇｄ、Ｔｂ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕ、Ｐｂ、Ｂｉ、Ｍｎ、及びＹからなる群から選ばれる少なくとも一種を含み、ＢはＲｕ、Ｚｒ、Ｓｎ、Ｈｆ、Ｔｉ、Ｔａ、Ｎｂ、Ｖ、Ｓｂ、及びＩｒからなる群から選ばれる少なくとも一種を含む。）
で表されるパイロクロア型酸化物である請求項１乃至４のいずれか１項に記載の電極材料。 The metal oxide particles are represented by the general formula A 2 B 2 O 7-Z.
(However, A and B each represent a metal element, Z represents a number from 0 to 1, A represents La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Including at least one selected from the group consisting of Lu, Pb, Bi, Mn, and Y, and B is at least selected from the group consisting of Ru, Zr, Sn, Hf, Ti, Ta, Nb, V, Sb, and Ir. Including one kind.)
Electrode material according to any one of claims 1 to 4 which is in pyrochlore type oxide represented.
前記電解質膜の一方の面に設けられているカソード触媒層と、
前記電解質膜の一方の面に設けられているアノード触媒層と、
を備え、
前記カソード触媒層が請求項１乃至５のいずれかに記載の電極材料を備えることを特徴とする膜電極接合体。 An electrolyte membrane having ionic conductivity;
A cathode catalyst layer provided on one surface of the electrolyte membrane;
An anode catalyst layer provided on one surface of the electrolyte membrane;
With
A membrane electrode assembly, wherein the cathode catalyst layer comprises the electrode material according to any one of claims 1 to 5 .
前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程と、を含み、
前記金属酸化物粒子の表面の少なくとも一部を多孔性無機材料で被覆する工程の後に、
さらに、前記多孔性無機材料の細孔表面を、塩基性官能基で修飾する工程を行うことを特徴とする電極材料の製造方法。 Producing an electrocatalyst comprising metal oxide particles active in oxygen reduction;
Look including the the steps of coating a porous inorganic material at least a part of the surface of the metal oxide particles,
After the step of coating at least part of the surface of the metal oxide particles with a porous inorganic material,
Furthermore, the process of modifying the pore surface of the said porous inorganic material with a basic functional group is performed , The manufacturing method of the electrode material characterized by the above-mentioned.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013098493A JP6086809B2 (en) | 2013-05-08 | 2013-05-08 | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material |
| PCT/JP2014/002076 WO2014181498A1 (en) | 2013-05-08 | 2014-04-10 | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013098493A JP6086809B2 (en) | 2013-05-08 | 2013-05-08 | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014220111A JP2014220111A (en) | 2014-11-20 |
| JP6086809B2 true JP6086809B2 (en) | 2017-03-01 |
Family
ID=51866990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013098493A Active JP6086809B2 (en) | 2013-05-08 | 2013-05-08 | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP6086809B2 (en) |
| WO (1) | WO2014181498A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6279366B2 (en) * | 2014-03-14 | 2018-02-14 | Ｊｘｔｇエネルギー株式会社 | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material |
| KR102272379B1 (en) * | 2017-06-23 | 2021-07-02 | 코오롱인더스트리 주식회사 | Electrode with organic metal-oxide, method for manufacturing the same, membrane-electrode assembly comprising the same, and fuel cell comprising the membrane-electrode assembly |
| EP3698425A4 (en) | 2017-10-20 | 2021-08-04 | Lockheed Martin Energy, LLC | pH BUFFERING REGION IN A FLOW BATTERY REBALANCING CELL |
| TWI663769B (en) * | 2018-02-13 | 2019-06-21 | National Taiwan University Of Science And Technology | Method of preparing an oligomer additive, oligomer additive and lithium battery |
| JP7081762B2 (en) * | 2018-03-30 | 2022-06-07 | Fdk株式会社 | Manufacturing method of catalyst for air secondary battery, manufacturing method of air secondary battery, catalyst for air secondary battery and air secondary battery |
| DE102018214403A1 (en) | 2018-08-27 | 2020-02-27 | Audi Ag | Process for the production of a catalyst free of precious metals, catalyst free of precious metals, fuel cell and motor vehicle |
| JP6799346B1 (en) * | 2020-05-21 | 2020-12-16 | 学校法人同志社 | Oxygen catalyst, electrodes using the oxygen catalyst, and electrochemical measurement method |
| WO2023219648A1 (en) | 2022-05-09 | 2023-11-16 | Lockheed Martin Energy, Llc | Flow battery with a dynamic fluidic network |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4980277B2 (en) * | 2008-03-26 | 2012-07-18 | 国立大学法人福井大学 | Electrode for electrochemical use, production method thereof, and electrolysis method using the same |
| JP5332429B2 (en) * | 2008-09-11 | 2013-11-06 | 日産自動車株式会社 | Electrocatalyst |
| JP5669432B2 (en) * | 2010-05-06 | 2015-02-12 | Ｊｘ日鉱日石エネルギー株式会社 | Membrane electrode assembly, fuel cell, and fuel cell activation method |
| JP5503465B2 (en) * | 2010-08-30 | 2014-05-28 | Ｊｘ日鉱日石エネルギー株式会社 | Method for preparing pyrochlore oxide catalyst and method for producing electrode catalyst for fuel cell |
-
2013
- 2013-05-08 JP JP2013098493A patent/JP6086809B2/en active Active
-
2014
- 2014-04-10 WO PCT/JP2014/002076 patent/WO2014181498A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| WO2014181498A1 (en) | 2014-11-13 |
| JP2014220111A (en) | 2014-11-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6086809B2 (en) | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material | |
| JP4656572B2 (en) | ELECTRODE FOR FUEL CELL, METHOD FOR PRODUCING ELECTRODE FOR FUEL CELL, AND FUEL CELL | |
| US8846271B2 (en) | Electrode material | |
| JP7101119B2 (en) | catalyst | |
| JP5956312B2 (en) | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material | |
| JP2006260844A (en) | Catalyst for fuel cell electrode, fuel cell electrode, membrane electrode assembly, and fuel cell | |
| US20190027738A1 (en) | Multi-functional electrode additive | |
| JP2008181696A (en) | Catalyst for fuel cell and its manufacturing method | |
| JP5669432B2 (en) | Membrane electrode assembly, fuel cell, and fuel cell activation method | |
| WO2006068315A2 (en) | Electrode catalyst for fuel cell and fuel cell | |
| JP2016091878A (en) | Method for manufacturing electrode material, membrane-electrode assembly and fuel cell stack | |
| JP6852886B2 (en) | Core-shell carrier for electrode material, its manufacturing method, and electrode material | |
| JP2007042519A (en) | Catalyst for fuel cell, its manufacturing method, and electrode for fuel cell and fuel cell using it | |
| JP4789179B2 (en) | Electrode catalyst and method for producing the same | |
| WO2006090907A1 (en) | Catalyst for fuel cell, membrane electrode assembly, and solid polymer electrolyte fuel cell | |
| JP6279366B2 (en) | Electrode material, membrane electrode assembly, fuel cell stack, and method for producing electrode material | |
| JP2005317467A (en) | Electrode for fuel cell and mea for fuel cell using the same | |
| WO2018069979A1 (en) | Catalyst layer production method, catalyst layer, catalyst precursor, and catalyst precursor production method | |
| JP5568111B2 (en) | Polymer electrolyte fuel cell | |
| JP2009048826A (en) | Electrode material for fuel cell and manufacturing method thereof, electrode for fuel cell, and fuel cell | |
| JP5090717B2 (en) | Polymer electrolyte fuel cell | |
| WO2020235322A1 (en) | Fuel cell cathode, method for producing same and solid polymer fuel cell equipped with fuel cell cathode | |
| JP2016091879A (en) | Fuel cell and fuel cell stack | |
| JP6846210B2 (en) | Electrode catalyst and membrane electrode assembly and fuel cell using the electrode catalyst | |
| JP6950255B2 (en) | Fuel cell catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20151218 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160719 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20160915 |
|
| 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: 20170117 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170131 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6086809 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| 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 |