WO2013084825A1 - バイオマス・有機・無機物の高効率分解浄化及び同時発電と水素生産の方法とそのためのバイオマス・有機・無機物直接燃料電池 - Google Patents
バイオマス・有機・無機物の高効率分解浄化及び同時発電と水素生産の方法とそのためのバイオマス・有機・無機物直接燃料電池 Download PDFInfo
- Publication number
- WO2013084825A1 WO2013084825A1 PCT/JP2012/081121 JP2012081121W WO2013084825A1 WO 2013084825 A1 WO2013084825 A1 WO 2013084825A1 JP 2012081121 W JP2012081121 W JP 2012081121W WO 2013084825 A1 WO2013084825 A1 WO 2013084825A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- liquid phase
- fuel cell
- metal
- layer
- composite anode
- Prior art date
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 187
- 239000002028 Biomass Substances 0.000 title claims abstract description 107
- 238000000034 method Methods 0.000 title claims abstract description 77
- 229910010272 inorganic material Inorganic materials 0.000 title claims abstract description 34
- 239000001257 hydrogen Substances 0.000 title claims abstract description 30
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 30
- 230000005611 electricity Effects 0.000 title claims abstract description 22
- 239000011147 inorganic material Substances 0.000 title 2
- 239000011368 organic material Substances 0.000 title 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 title 1
- 239000004065 semiconductor Substances 0.000 claims abstract description 189
- 239000003054 catalyst Substances 0.000 claims abstract description 131
- 239000002131 composite material Substances 0.000 claims abstract description 123
- 239000007791 liquid phase Substances 0.000 claims abstract description 109
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 59
- 239000001301 oxygen Substances 0.000 claims abstract description 59
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 58
- 239000007864 aqueous solution Substances 0.000 claims abstract description 50
- 239000007789 gas Substances 0.000 claims abstract description 46
- 239000002699 waste material Substances 0.000 claims abstract description 46
- 238000006243 chemical reaction Methods 0.000 claims abstract description 43
- 239000007900 aqueous suspension Substances 0.000 claims abstract description 39
- 150000002484 inorganic compounds Chemical class 0.000 claims abstract description 32
- 230000036647 reaction Effects 0.000 claims abstract description 32
- 150000002894 organic compounds Chemical class 0.000 claims abstract description 31
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 230000009467 reduction Effects 0.000 claims abstract description 28
- 230000005501 phase interface Effects 0.000 claims abstract description 27
- 239000007788 liquid Substances 0.000 claims abstract description 26
- 239000012071 phase Substances 0.000 claims abstract description 25
- 229910052751 metal Inorganic materials 0.000 claims description 116
- 239000002184 metal Substances 0.000 claims description 116
- 239000000758 substrate Substances 0.000 claims description 75
- 238000010248 power generation Methods 0.000 claims description 47
- 238000000354 decomposition reaction Methods 0.000 claims description 23
- 238000000576 coating method Methods 0.000 claims description 22
- 239000011248 coating agent Substances 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 17
- 229910044991 metal oxide Inorganic materials 0.000 claims description 16
- 150000004706 metal oxides Chemical class 0.000 claims description 16
- 239000012298 atmosphere Substances 0.000 claims description 14
- 238000000746 purification Methods 0.000 claims description 13
- 150000003839 salts Chemical class 0.000 claims description 12
- 238000002347 injection Methods 0.000 claims description 6
- 239000007924 injection Substances 0.000 claims description 6
- 239000003923 scrap metal Substances 0.000 claims description 6
- 230000001590 oxidative effect Effects 0.000 claims description 5
- 239000011148 porous material Substances 0.000 claims description 5
- 239000000243 solution Substances 0.000 abstract description 12
- 239000003344 environmental pollutant Substances 0.000 abstract description 8
- 230000003197 catalytic effect Effects 0.000 abstract description 5
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 83
- 239000010408 film Substances 0.000 description 45
- 239000010409 thin film Substances 0.000 description 26
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 25
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 24
- 239000008103 glucose Substances 0.000 description 24
- 229910052697 platinum Inorganic materials 0.000 description 24
- 239000010936 titanium Substances 0.000 description 24
- 238000006722 reduction reaction Methods 0.000 description 22
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 21
- 229910010413 TiO 2 Inorganic materials 0.000 description 21
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 17
- 229910001868 water Inorganic materials 0.000 description 17
- 239000002585 base Substances 0.000 description 15
- 150000001875 compounds Chemical class 0.000 description 14
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 12
- 230000000694 effects Effects 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 11
- 239000012528 membrane Substances 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 10
- 239000010949 copper Substances 0.000 description 10
- 239000004408 titanium dioxide Substances 0.000 description 10
- 229910002092 carbon dioxide Inorganic materials 0.000 description 9
- 239000001569 carbon dioxide Substances 0.000 description 9
- 150000002739 metals Chemical class 0.000 description 9
- 238000002256 photodeposition Methods 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 7
- 238000005452 bending Methods 0.000 description 7
- 239000004020 conductor Substances 0.000 description 7
- 229910052802 copper Inorganic materials 0.000 description 7
- 229920000642 polymer Polymers 0.000 description 7
- 230000004888 barrier function Effects 0.000 description 6
- 238000000151 deposition Methods 0.000 description 6
- 238000004070 electrodeposition Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 229910052742 iron Inorganic materials 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 6
- 238000007670 refining Methods 0.000 description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 5
- 239000003792 electrolyte Substances 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 239000002932 luster Substances 0.000 description 5
- 239000002245 particle Substances 0.000 description 5
- 238000010672 photosynthesis Methods 0.000 description 5
- 230000029553 photosynthesis Effects 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 229920000557 Nafion® Polymers 0.000 description 4
- 238000002485 combustion reaction Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 239000010419 fine particle Substances 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- 238000006303 photolysis reaction Methods 0.000 description 4
- 229910052709 silver Inorganic materials 0.000 description 4
- 239000004332 silver Substances 0.000 description 4
- 229910052717 sulfur Inorganic materials 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- 102000004190 Enzymes Human genes 0.000 description 3
- 108090000790 Enzymes Proteins 0.000 description 3
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 239000002803 fossil fuel Substances 0.000 description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 3
- 229910052737 gold Inorganic materials 0.000 description 3
- 239000010931 gold Substances 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 230000015843 photosynthesis, light reaction Effects 0.000 description 3
- 229910052700 potassium Inorganic materials 0.000 description 3
- 239000011591 potassium Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 230000027756 respiratory electron transport chain Effects 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- 238000010792 warming Methods 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- YRKCREAYFQTBPV-UHFFFAOYSA-N acetylacetone Chemical compound CC(=O)CC(C)=O YRKCREAYFQTBPV-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000003912 environmental pollution Methods 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- -1 for example Substances 0.000 description 2
- 239000003574 free electron Substances 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000000813 microbial effect Effects 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 229910052762 osmium Inorganic materials 0.000 description 2
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 2
- 238000007540 photo-reduction reaction Methods 0.000 description 2
- 150000003057 platinum Chemical class 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000004094 surface-active agent Substances 0.000 description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 2
- 229910001887 tin oxide Inorganic materials 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- WUPHOULIZUERAE-UHFFFAOYSA-N 3-(oxolan-2-yl)propanoic acid Chemical compound OC(=O)CCC1CCCO1 WUPHOULIZUERAE-UHFFFAOYSA-N 0.000 description 1
- 229920003934 Aciplex® Polymers 0.000 description 1
- 229920000936 Agarose Polymers 0.000 description 1
- 229920003935 Flemion® Polymers 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 241000872198 Serjania polyphylla Species 0.000 description 1
- 229910006404 SnO 2 Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 239000002154 agricultural waste Substances 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 1
- 239000002551 biofuel Substances 0.000 description 1
- 230000033558 biomineral tissue development Effects 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 229910052980 cadmium sulfide Inorganic materials 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000007606 doctor blade method Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 239000012776 electronic material Substances 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 238000004817 gas chromatography Methods 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 229910021432 inorganic complex Inorganic materials 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 244000144972 livestock Species 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- QGLKJKCYBOYXKC-UHFFFAOYSA-N nonaoxidotritungsten Chemical compound O=[W]1(=O)O[W](=O)(=O)O[W](=O)(=O)O1 QGLKJKCYBOYXKC-UHFFFAOYSA-N 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000001782 photodegradation Methods 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 150000003384 small molecules Chemical class 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 125000000542 sulfonic acid group Chemical group 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000010408 sweeping Methods 0.000 description 1
- TXEYQDLBPFQVAA-UHFFFAOYSA-N tetrafluoromethane Chemical compound FC(F)(F)F TXEYQDLBPFQVAA-UHFFFAOYSA-N 0.000 description 1
- 229910001930 tungsten oxide Inorganic materials 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
- C25D7/12—Semiconductors
-
- 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
- H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
- H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
- H01M8/04186—Arrangements for control of reactant parameters, e.g. pressure or concentration of liquid-charged or electrolyte-charged reactants
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09B—DISPOSAL OF SOLID WASTE NOT OTHERWISE PROVIDED FOR
- B09B3/00—Destroying solid waste or transforming solid waste into something useful or harmless
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/08—Reclamation of contaminated soil chemically
- B09C1/085—Reclamation of contaminated soil chemically electrochemically, e.g. by electrokinetics
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/02—Hydrogen or oxygen
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B5/00—Electrogenerative processes, i.e. processes for producing compounds in which electricity is generated simultaneously
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/86—Inert electrodes with catalytic activity, e.g. for fuel cells
- H01M4/90—Selection of catalytic material
- H01M4/92—Metals of platinum group
- H01M4/925—Metals of platinum group supported on carriers, e.g. powder carriers
-
- 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
- H01M8/06—Combination of fuel cells with means for production of reactants or for treatment of residues
- H01M8/0606—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants
- H01M8/0656—Combination of fuel cells with means for production of reactants or for treatment of residues with means for production of gaseous reactants by electrochemical means
-
- 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
- H01M8/08—Fuel cells with aqueous electrolytes
-
- 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
- H01M8/16—Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
-
- 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
- H01M8/22—Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen
-
- 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
- H01M4/8846—Impregnation
- H01M4/885—Impregnation followed by reduction of the catalyst salt precursor
-
- 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
- H01M4/8853—Electrodeposition
-
- 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
- H01M4/9041—Metals or alloys
-
- 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
- H01M4/9041—Metals or alloys
- H01M4/905—Metals or alloys specially used in fuel cell operating at high temperature, e.g. SOFC
- H01M4/9066—Metals or alloys specially used in fuel cell operating at high temperature, e.g. SOFC of metal-ceramic composites or mixtures, e.g. cermets
-
- 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
-
- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/30—Wastewater or sewage treatment systems using renewable energies
- Y02W10/37—Wastewater or sewage treatment systems using renewable energies using solar energy
Definitions
- the present invention relates to a method for generating and simultaneously generating power while simultaneously decomposing and purifying biomass / organic / inorganic compounds, wastes / waste liquids, environmental pollutants, etc. with high efficiency by catalytic action without irradiating light, and fuel for performing the same It relates to batteries.
- the present invention is positioned as a core technology of a next-generation sustainable energy resource system that decomposes and purifies biomass and waste generated from sunlight as an energy resource and simultaneously generates power.
- An object of the present invention is to establish a future core energy system to replace fossil fuels and nuclear power generation, and to provide such a system.
- the present invention will generate electricity by efficiently extracting electric charges directly from biomass and oxygen without inefficient combustion and heat. This is equivalent to the second energy revolution in which electric charges are directly extracted from biomass using light as an energy resource.
- fuel cells As a method of generating electricity from biomass, organic matter, or liquid containing a particularly large amount of water, fuel cells have been proposed and research and development are being carried out.
- fuel cells when using hydrogen or methanol as limited fuels, power generation has been put to practical use.
- other fuels, especially various biomass, biomass waste or organic Direct generation with a fuel cell is difficult with inorganic compounds.
- research on biomass power generation using enzymes, microorganisms, or carbon-supported platinum as a catalyst has been made, but their efficiency has been extremely low, and no technology has reached a practical level.
- Patent Document 1 As “photophysical chemical battery”.
- Patent Document 2 “Biophotochemical cell and its utilization method” are disclosed in Patent Document 2
- Patent Document 3 “Biophotochemical cell and module, analyzer, teaching material and their utilization method” are disclosed in Patent Document 3.
- Bio-photochemical battery that generates and generates electricity simultaneously with high-efficiency photolysis and purification of biomass, organic / inorganic compounds or waste / waste liquid”, and “Photodecomposition and purification of compounds and liquids using the bio-photochemical battery” And a method for generating electric power at the same time ” was proposed in Patent Document 4.
- an object of the present invention is to provide an apparatus and method for decomposing, purifying, and generating electric power of a fuel such as biomass by a fuel cell reaction without irradiating light, that is, without adding external energy. It is.
- biomass, organic and inorganic compounds that can be used as fuel, wastes and waste liquids, environmental pollutants, etc. are electron-donating, so they are essentially compounds that can react with oxygen without using external energy such as light. . Therefore, if a novel and highly efficient catalyst that has never been seen before is created, and the catalyst is used as an anode and combined with an oxygen reduction cathode electrode as a counter electrode, fuel can be used without using other energy such as light. High efficiency power generation should be possible at the same time as high efficiency decomposition and purification by battery reaction. From this point of view, the present inventors have arrived at the present invention by searching for a catalyst capable of efficiently decomposing electron donating compounds such as biomass / organic / inorganic compounds, waste / waste liquid, and environmental pollutants without light irradiation.
- a method of decomposing, purifying and generating electric power by fuel cell reaction without adding external energy (A) Electrode substrate layer / porous material obtained by coating a porous semiconductor film layer on a conductive electrode substrate layer and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer Preparing a composite anode consisting of three layers of semiconductor layer / catalyst layer; (B) immersing the composite anode in a liquid phase comprising an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds or a mixture thereof as a fuel, or In contact with the liquid phase, (C) A counter electrode for oxygen reduction is installed in the liquid phase consisting of the aqueous solution or aqueous suspension, or at the liquid phase / gas phase interface with the gas phase in contact with the liquid phase, (D) Supplying or coexisting oxygen
- cleaning of the following fuels is provided.
- a fuel cell comprising a composite anode and a counter electrode for oxygen reduction, and performing decomposition, purification and power generation of the fuel by a fuel cell reaction without applying external energy
- the composite anode is formed by coating a porous semiconductor film layer on a conductive electrode substrate layer, and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer.
- the composite anode is immersed in a liquid phase consisting of an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds or a mixture thereof as a fuel, or In contact with the liquid phase,
- the counter electrode for oxygen reduction is installed in a liquid phase / gas phase interface with a liquid phase comprising the aqueous solution or aqueous suspension or with a gas phase in contact with the liquid phase
- D It is configured to cause a fuel cell reaction on the cathode by supplying or coexisting oxygen in the liquid phase where the cathode is installed or in the liquid phase / gas phase interface.
- a fuel cell that generates power simultaneously with decomposing and purifying the fuel without adding external energy.
- a method of obtaining pure metal at the cathode simultaneously with fuel cell power generation without adding external energy (A) Electrode substrate layer / porous material obtained by coating a porous semiconductor film layer on a conductive electrode substrate layer and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer Preparing a composite anode consisting of three layers of semiconductor layer / catalyst layer; (B) immersing the composite anode in a liquid phase consisting of an aqueous solution or aqueous suspension containing at least any of biomass, biomass waste, and organic / inorganic compounds or mixtures thereof, or In contact with the liquid phase, (C) A counter electrode for oxygen reduction is installed in the liquid phase consisting of the aqueous solution or aqueous suspension, or at the liquid phase / gas phase interface with the gas phase in contact with the liquid phase, (D) The atmosphere of the liquid phase or the liquid
- a fuel cell characterized by causing an oxide of a recovered metal or a metal obtained by oxidizing a scrap metal or a salt or complex salt thereof to coexist as an electron acceptor to cause a fuel cell reaction on the cathode.
- a fuel cell comprising a composite anode and a counter electrode for oxygen reduction, performing fuel cell power generation without applying external energy, and simultaneously obtaining pure metal at the cathode
- a fuel cell comprising a composite anode and a counter electrode for oxygen reduction, performing fuel cell power generation without applying external energy, and simultaneously obtaining pure metal at the cathode
- a fuel cell comprising a composite anode and a counter electrode for oxygen reduction, performing fuel cell power generation without applying external energy, and simultaneously obtaining pure metal at the cathode
- the composite anode is formed by coating a porous semiconductor film layer on a conductive electrode substrate layer, and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer.
- the composite anode is immersed in a liquid phase consisting of an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds or a mixture thereof as a fuel, or In contact with the liquid phase,
- the counter electrode for oxygen reduction is installed in a liquid phase consisting of the aqueous solution or aqueous suspension or a liquid phase / gas phase interface with a gas phase in contact with the liquid phase,
- D keeping the atmosphere of the liquid phase or the liquid phase / gas phase interface where the cathode is installed under anaerobic conditions, and in the liquid phase or the liquid phase / gas phase interface,
- a fuel cell power generation characterized by coexisting, as an electron acceptor, an oxide of these metals or an oxide of those metals generated by oxidizing the recovered metal or scrap metal, or a salt or complex salt thereof, and
- the following method for producing hydrogen using a micro fuel cell is provided.
- a method for obtaining hydrogen on an anode at the same time that a composite anode is provided and micro-fuel cell power generation is performed on the anode without applying external energy (A) The composite anode is formed by coating a porous semiconductor film layer on a conductive electrode substrate layer, and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer.
- a micro fuel cell comprising a composite anode for performing micro fuel cell power generation on the anode without applying external energy and simultaneously obtaining hydrogen on the anode
- a micro fuel cell is formed by coating a porous semiconductor film layer on a conductive electrode substrate layer, and forming a catalyst film layer made of metal, metal oxide, or semiconductor on the semiconductor layer.
- biomass or its waste or other organic compounds or inorganic compounds can be directly used as fuel to decompose and extract electric power by fuel cell reaction. It was hardly possible in practical use except in the case of limited specific items.
- a specific composite anode composed of an anode electrode base layer / porous semiconductor thin film layer / metal catalyst layer is used together with a cathode electrode for oxygen reduction so far.
- Biomass, its waste, or other organic or inorganic compounds can be used directly as fuel, and without any light irradiation, it can be decomposed and purified with high efficiency by the fuel cell reaction to extract electric power. become.
- biomass, waste thereof, or other organic / inorganic compounds that could not be used as fuel for conventional fuel cells are used as fuel, and this is decomposed by fuel cell reaction without light irradiation. Power can be taken out, so a basic sustainable energy resource system can be constructed.
- FIG. 1 shows a cell configuration composed of an [electrode base layer / n-type semiconductor layer / metal catalyst layer] composite as a highly active anode catalyst electrode, a Schottky junction (barrier) formation in a semiconductor, and a counter electrode cathode, and decomposition of biomass, etc.
- -It is a conceptual diagram which shows a power generation mechanism.
- FIG. 2 is a graph of IV characteristics showing the results of the example.
- FIG. 3 is a graph showing the dependence of the maximum output on the Pt / Ti atomic ratio showing the results of the examples.
- I electron donor
- the catalyst (C) and the substrate (S, in this case, fuel) first form an active complex (CS, a kind of intermediate) when the substrate approaches the catalyst. Thereafter, electron transfer from the fuel to the catalyst occurs, and as shown in the formula (1), it is divided into C ⁇ and S + (fuel oxide).
- the electrons that have moved to the catalyst move to the counter electrode, where they are passed to oxygen to reduce the oxygen and produce water.
- the fuel oxide (S + ) reacts with the catalyst one after another and is oxidized. Finally, carbon becomes carbon dioxide (CO 2 ), and nitrogen becomes (nitrogen molecule, N 2 ), which rides in natural circulation.
- a Schottky barrier bending of the band structure formed between the catalyst layer and the semiconductor by bringing the n-type semiconductor into contact with the catalyst layer.
- the band structure of the semiconductor (valence band VB and conduction band CB) bends at the interface between the n-type semiconductor and the solution or metal later, and this part (called the space charge layer or the depletion layer) electronic (e -) along the slope, move to lower energy downward direction (in Fig. 1 left).
- the electrons that have moved to the semiconductor layer reach the conductive portion of the anode electrode (conductive electrode substrate 30) and then cross the external cathode (external circuit) 42 to the counter cathode 40, where they reduce oxygen. Water is generated and power generation by fuel cell reaction is completed.
- the current flowing in the external circuit flows in the direction from the cathode toward the anode.
- the object can be achieved by forming a porous n-type semiconductor thin film on the electrode serving as the base of the anode and forming a catalyst layer on the surface of the porous semiconductor.
- the present invention basically includes the following fuel cell power generation method [1] and fuel cell [2]. That is, [1] A method of decomposing, purifying, and generating electricity by fuel cell reaction without adding external energy, (A) An electrode substrate layer obtained by coating a layer of the porous semiconductor film 20 on the conductive electrode substrate layer 30 and forming a layer of the catalyst film 10 made of metal, metal oxide, or semiconductor on the semiconductor layer.
- a composite anode 2 consisting of three layers: / porous semiconductor layer / catalyst layer; (B) immersing the composite anode in a liquid phase comprising an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds or a mixture thereof as a fuel, or In contact with the liquid phase, (C) A counter electrode for oxygen reduction is installed in the liquid phase consisting of the aqueous solution or aqueous suspension, or at the liquid phase / gas phase interface with the gas phase in contact with the liquid phase, (D) adding external energy, characterized by causing a fuel cell reaction on the cathode by supplying or coexisting oxygen in the liquid phase where the cathode is installed or at the liquid phase / gas phase interface Without decomposing and purifying the fuel by the fuel cell reaction of the fuel, and simultaneously generating power,
- a fuel cell comprising the composite anode 2 and the counter electrode 40 for oxygen reduction, and performing decomposition, purification and power generation of the fuel by a fuel cell reaction without applying external energy,
- a porous semiconductor film layer 20 is coated on a conductive electrode substrate layer 30, and a catalyst film layer 10 made of a metal, metal oxide, or semiconductor is formed on the semiconductor layer.
- a composite anode comprising three layers of an electrode substrate layer / a porous semiconductor layer / a catalyst layer formed;
- the composite anode is immersed in a liquid phase composed of an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds or a mixture thereof as a fuel, or the liquid In contact with the phase,
- the counter electrode for oxygen reduction is installed in a liquid phase / gas phase interface with a liquid phase comprising the aqueous solution or aqueous suspension or with a gas phase in contact with the liquid phase
- D It is configured to cause a fuel cell reaction on the cathode by supplying or coexisting oxygen in the liquid phase where the cathode is installed or at the liquid phase / gas phase interface.
- the present invention provides a fuel cell that generates power at the same time as decomposing and purifying the fuel without adding external energy. (See FIG. 1 for symbols here.)
- the specific composite anode defined in the present invention is used, and the composite anode is basically composed of a three-layer composite of a conductive electrode layer, a semiconductor layer, and a catalyst layer as a base.
- an electrode formed by coating a porous semiconductor film layer on a conductive electrode substrate layer and forming a catalyst film layer made of a metal, metal oxide, or semiconductor on the semiconductor layer. It is a composite anode composed of three layers of base layer / porous semiconductor layer / catalyst layer.
- conductive electrode substrates include, for example, conductive glass electrodes such as ITO and FTO, metals such as titanium, copper, iron, aluminum, silver, gold, and platinum, and organic or polymer conductive materials such as carbon and felt.
- conductive glass electrodes such as ITO and FTO
- metals such as titanium, copper, iron, aluminum, silver, gold, and platinum
- organic or polymer conductive materials such as carbon and felt.
- an n-type semiconductor is mainly used.
- titanium dioxide, zinc oxide, tin oxide, tungsten oxide, cadmium sulfide, an organic semiconductor, or a polymer semiconductor is not particularly limited.
- the semiconductor layer in order to increase the interface area between the semiconductor / catalyst layers, as described above, is preferably a porous film (porous semiconductor film) in which the semiconductor is a nanostructured porous body. It is preferable that it consists of.
- the nanostructure is one having a pore diameter of 0.1 nm to several thousand nm, preferably 2 nm to several hundred nm, more preferably about 10 nm to 50 nm, and a specific surface area of 1 to 10,000 m 2 / g. (Note that the effective surface area of the porous membrane ranges from 2 to several thousand times the apparent surface area, usually several hundred to 2000 times.)
- a known oxidation catalyst or reduction catalyst is used, for example, platinum, gold, iridium, osmium, manganese, iron, cobalt, nickel, copper, zinc, molybdenum, ruthenium, rhodium as a metal.
- Palladium, silver, cadmium, indium and the like are not particularly limited.
- oxides of these metals, semiconductors, inorganic complexes, organic catalysts, polymer catalysts, or the like are used.
- a catalyst often has reaction specificity with respect to a substrate to be decomposed (that is, a fuel such as biomass or a related compound).
- a substrate to be decomposed that is, a fuel such as biomass or a related compound.
- the composite anode of the present invention can decompose various substrates and generate power. If necessary, when processing mixed biomass having different compositions, there is an effective metal catalyst for each biomass, so select the catalyst such as the metal, and thus the most preferred different metals
- biomass compounds are multi-electron reactive, for example, typical glucose is a 24-electron donor per molecule.
- a multi-electron decomposable catalyst is required, but there has been no such catalyst.
- the catalyst such as metal in the composite anode of the present invention has a bent band structure based on a Schottky junction generated in a semiconductor and an ohmic junction between the semiconductor and the catalyst (smooth electron transfer from the catalyst to the semiconductor based on Ohm's law).
- This is a multi-electron decomposition / power generation catalyst that can use 100% of the electrons that can be provided by biomass because of its extremely high activity.
- Such ohmic junctions do not occur between ordinary semiconductors / catalysts, but in the present invention, since the semiconductor is a nanostructured porous body, smooth electron transfer from the catalyst to the semiconductor is possible based on Ohm's law. It becomes.
- the method for producing a semiconductor porous film on the conductive electrode substrate layer is not particularly limited.
- the following method using semiconductor fine particles as a starting material (coating, firing method, etc.) ) Is adopted.
- semiconductor fine particles having an average particle diameter of 1 nm to 1 mm preferably 10 nm to 1000 nm, more preferably about 10 nm to 500 nm (for example, anatase type, rutile type, brookite type in the case of titanium dioxide fine particles, or a combination of these two or A three-part mixed type) is prepared, a surfactant for promoting dispersion, an organic medium, water, and the like are added in small amounts, and they are well kneaded and mixed in a mortar or ball mill to prepare a semiconductor paste.
- the semiconductor paste a commercially available paste can be selected and used. For example, a paste of TiO 2 nanoparticles can be used.
- Conductive glass coated with a conductive tin oxide thin film which is manufactured or selected from a commercially available semiconductor paste and imparted heat resistance by doping with a conductive electrode substrate, for example, fluorine (referred to as FTO). It is applied on a conductive electrode substrate made of the above by a screen printing method, a squeeze method, a doctor blade method, a spin coating method, a coating method, or the like.
- FTO fluorine
- any conductive electrode substrate can be used, including conductive metals such as copper, titanium, iron, cobalt, nickel, zinc, platinum, gold, silver, organic conductors, A polymer conductor or the like is used, but of course not limited thereto.
- the paste coating film is first heated and dried at, for example, 100 ° C. for about 30 minutes, and further, the paste coating and drying are repeated several times as necessary to obtain a desired thickness. Finally, for example, sintering is performed at 450 ° C. for about 30 minutes to obtain an anode (anode substrate) in which a porous semiconductor thin film layer is coated on a conductive electrode substrate. (On this anode substrate, a composite anode is formed by coating the catalyst layer in the next step.) If the viscosity of the paste is adjusted, a thin film having a predetermined thickness can be obtained even by a single application. The process is simplified.
- the thickness of the porous semiconductor film layer is basically about 10 nm to 1 mm, preferably about 5 ⁇ m to 100 ⁇ m, more preferably about 5 ⁇ m to 50 ⁇ m.
- the film thickness is too large, the adhesion to the electrode substrate decreases. Therefore, it is preferable to select an appropriate film thickness within the above range.
- a paste of titanium dioxide fine particles average particle size: 13 nm
- the effective surface area of the porous thin film is 2000 times the apparent area. Therefore, its activity becomes extremely high.
- a composite anode is produced by forming a catalyst film layer on an anode substrate coated with a porous semiconductor thin film layer on an electrode substrate.
- the thickness of the catalyst layer is about 0.1 nm to 1 mm, preferably about 0.2 nm to 100 ⁇ m, more preferably about 0.4 nm to 30 ⁇ m.
- the catalyst film is produced by depositing a metal or its oxide from a corresponding metal salt on the porous semiconductor thin film by a photoreduction method (photodeposition method), or by an electrochemical reduction method.
- photoreduction method photodeposition method
- electrochemical reduction method Various methods known per se, such as a method of depositing an oxide or the like (electrochemical deposition method) or a chemical plating method are employed.
- FTO basically gives good activity as the anode base electrode.
- the FTO-based electrode has problems that it is not suitable for upsizing because its conductivity is lower than that of metal, or the cost is high.
- a highly conductive metal substrate electrode such as Ti or Cu
- a highly conductive substrate electrode such as graphite or carbon
- the conductivity does not decrease so much even if the anode area is increased. Since the characteristics do not deteriorate, good results are given.
- the TiO 2 porous semiconductor thin film-coated anode substrate is immersed in a mixed aqueous solution of methanol and chloroplatinic acid, White light is irradiated from the semiconductor thin film side or the conductive electrode side.
- Pt / Ti atomic ratio ⁇ is preferably about 0.01 / 1-1000 / 1 as will be described later.
- Electrons (e ⁇ ) are excited to the conduction band (CB) from the valence band (VB) in the middle, and electron deficient holes (h + ) remain in VB. Immediately after excitation, these electrons and holes exist in an exciton state (a couple of excited electrons and holes) that has a short lifetime and recombines immediately.
- CB conduction band
- VB valence band
- h + electron deficient holes
- a junction (barrier) B is formed, the band structure is bent and has a potential gradient m. In the n-type semiconductor, this gradient advances in a positive potential direction (downward in FIG. 1) from the interface toward the inside. (However, with the p-type, the slope is reversed.)
- Exciton itself is unstable and has a short lifetime, so it recombines as it is, but due to the potential gradient (bending) in the space charge layer of this Schottky junction, the exciton holes in the n-type are semiconductor / liquid Since the electrons move toward the interface and the electrons move toward the inside of the semiconductor, positive and negative charges are separated. Since the holes emerge on the semiconductor surface, they accept electrons from the methanol electron donor in the liquid, and the electrons remain in the semiconductor. When these electrons accumulate, they move to the semiconductor / aqueous solution interface to reduce the platinum salt, and platinum is reduced to a zero-valent metal and simultaneously deposited on the semiconductor surface.
- platinum which is a catalyst
- potassium chloroplatinate which is a metal salt corresponding to platinum.
- the composite anode (electrode substrate layer / semiconductor layer / platinum catalyst layer) 2 is formed.
- the electrochemical deposition method Next, the electrochemical deposition method will be described.
- the porous semiconductor thin film-coated anode substrate is immersed in an aqueous solution in which the target metal salt is dissolved, and the electrolyte is dissolved as necessary to apply a sufficient reduction potential.
- the metal thin film as the catalyst can be formed by reducing the metal to zero valence by the constant current method or the constant voltage method and simultaneously depositing it on the semiconductor thin film. In this way, a composite anode (electrode base layer / semiconductor layer / catalyst layer) is formed.
- the metal catalyst such as Pt is deposited from the surface of the porous semiconductor, that is, deposited on the inner surface of the nanopore of the nanostructured porous body.
- a Schottky junction (barrier) B is formed near the metal interface (see FIG. 1). That is, since a composite composed of a porous semiconductor / metal is formed, the (porous semiconductor / metal) composite forms a so-called nano-order interfacial structure, and a Schottky near the semiconductor interface. Barrier B (bending of the band structure) is formed.
- the semiconductor since the semiconductor has a fine nanostructure as described above, the junction between the semiconductor and the catalyst has an ohmic property (charge is transported by Ohm's law). Become. For this reason, electrons easily move from the catalyst to the semiconductor smoothly. Because of this mechanism, the electrons transferred from the substrate (fuel to be decomposed) to the catalyst quickly move to the semiconductor layer, and the transferred electrons are then easily transferred into the semiconductor due to the bending of the band structure. It is considered that a mechanism for shifting the equilibrium system shown in (1) toward the generating system works.
- the metal Since a Schottky junction is formed between a semiconductor and a metal or an organic conductor, the metal is not partly on the semiconductor in a block shape, but covers the entire semiconductor as a thin layer of metal or the like. It is desirable that At the same time, the metal is preferably in a crystalline state. Since the metal crystal is characterized by containing free electrons, it usually has a metallic luster derived from free electrons. In fact, the present inventors have confirmed that the highly active anode often has a metallic luster when practicing the present invention.
- platinum can be deposited in a large amount by a desired amount.
- a large amount of platinum is deposited as a thin layer, and the catalytic activity is high under conditions that show metallic luster, such platinum metal crystals (which may be aggregates of microcrystals) than platinum black aggregates
- the composite anode thus prepared and prepared is a liquid comprising an aqueous solution or an aqueous suspension containing at least one of biomass, biomass waste, and organic / inorganic compounds, or a mixture thereof as a fuel. Immerse in the phase or contact with the liquid phase.
- the composite anode is plate-shaped and immersed in a cell container (tank container) containing a liquid phase containing biomass, but in some cases, the wall surface of the cell (or a part thereof) Can also be composed of the composite anode itself. In this case, the composite anode is in contact with the biomass-containing liquid phase, but this embodiment can be implemented.
- the cathode used as the counter electrode has an oxygen reduction catalyst function.
- an oxygen reduction catalyst such as platinum is dispersed or coated on a conductive electrode.
- the counter cathode may be installed in a liquid phase such as an aqueous solution, but the efficiency is high when gas phase oxygen is used. This is because the solubility of oxygen in water is low and the partial pressure of oxygen is about 1/5 under air, so the oxygen concentration (dissolved oxygen concentration) in the air underwater is as low as 0.2 mM or less.
- the counter electrode cathode has a structure in which gas-phase oxygen such as air can be used instead of dissolved oxygen in the liquid phase, so that the decomposition and power generation characteristics of the fuel cell are further improved.
- gas-phase oxygen such as air
- the oxygen concentration in terms of concentration per unit volume is about 0.2 mmol / L in water, but 45 mmol / L in the air phase, which is 225 times the concentration in water
- the oxygen diffusion coefficient ie, oxygen molecules Is a gas phase that is at least about five orders of magnitude larger than the liquid phase, so that the use of oxygen in the gas phase is advantageous.
- the cell structure When gas phase oxygen is used, the cell structure is such that one side of the counter cathode is in the liquid phase and the other side is in the gas phase.
- the cathode structure for achieving the purpose needs to be devised.
- MEA membrane electrode assembly
- a two-layer structure of electrolyte membrane such as Nafion membrane / platinum-supported carbon catalyst-dispersed carbon paper
- Nafion registered trademark of DuPont
- PTFE polytetrafluoroethylene
- the electrolyte membrane is preferable as a cation exchanger because it can permeate protons (H + ) necessary for reducing oxygen to produce water.
- usable electrolyte membranes include, but are not limited to, Aciplex (registered trademark of Asahi Kasei Co., Ltd.), Flemion (registered trademark of Asahi Glass Co., Ltd.), and the like.
- the cathode area should be large.
- the present inventors have found that when the cathode area is increased, the electric power that can be taken out exceeds the area increase (see Example 9).
- the dimensions and characteristics of the counter cathode are important factors for controlling the power generation rate (characteristics) as with the anode.
- the theoretical generation voltage (open electromotive force Voc) in this fuel cell is 1.2V to 1.3V, but according to the present inventors, it can actually reach 1.6V or more, It has been found that this greatly increases the generated power.
- the cathode uses a diaphragm such as a Nafion membrane, which is a proton conductor (proton exchanger), between the liquid and a catalyst such as platinum. This traps protons inside and concentrates them locally.
- the proton local concentration in the diaphragm is much higher than that in the liquid (that is, the pH is lowered), so that the Voc is greatly increased by shifting the cathode potential to the positive potential side. Inferred.
- the conductive electrode substrate layer produced as described above is coated with a porous semiconductor film layer, and a catalyst film layer made of a metal, metal oxide, or semiconductor is formed on the semiconductor layer.
- the composite anode consisting of electrode base layer / porous semiconductor layer / catalyst layer is composed of various fuels such as biomass and organic / inorganic compounds (hereinafter collectively referred to as substrates) depending on the combination of the porous semiconductor and the catalyst. It has a function of generating electricity at the same time as being decomposed and purified with high efficiency.
- FIG. 1 schematically showing the principle of the present invention
- a composite anode 2 composed of three layers of electrode base layer / porous semiconductor layer / catalyst layer, and counter electrode having an oxygen reduction catalyst function
- the cathode 40 When a fuel cell is configured by immersing the cathode 40 in a liquid phase composed of an aqueous solution or suspension of the substrate, the cell can decompose and purify the substrate without requiring other energy such as light irradiation to the cell. It can generate electricity at the same time.
- biomass direct fuel cell In the system constituting the fuel cell according to the present invention, in the anode, electrons are taken out from the substrate (fuel), and the electrons are carried to the cathode and passed to oxygen to obtain electric power.
- a fuel cell using a substrate such as biomass as a direct fuel referred to as “biomass direct fuel cell” or simply “direct fuel cell”.
- FIG. 1 shows the mechanism of decomposition and purification of a substrate by the composite anode 2 composed of an electrode substrate layer / porous semiconductor layer / catalyst layer and simultaneous power generation using such a fuel cell reaction.
- Reference numeral 5 denotes a fuel battery cell.
- the catalyst layer 10 such as platinum takes electrons from the substrate 12 such as biomass and decomposes the substrate oxidatively, and the taken electrons 14 are then subjected to space charge layers (band bending in the adjacent porous semiconductor layer 20). Since it is difficult to return to the original substrate by moving into the semiconductor by m), the equilibrium of equation (1) shifts toward the generation system.
- the electrons 14 that have moved into the porous semiconductor layer 20 move to the conductive portion of the anode electrode substrate 30 and pass through the external circuit 42 to the counter electrode cathode 40 (at this time, the current i flows from the counter electrode cathode 40 toward the composite anode). Where oxygen is reduced to produce water.
- biomass and its related compounds can be completely decomposed, and the final decomposition products are carbon dioxide (CO 2 ) and water (H 2 O), and N is nitrogen N 2 .
- These complete decomposition reactions are called mineralization. Since these decomposition products are also raw materials for photosynthesis, carbon dioxide, nitrogen and water on the earth have been circulated through photosynthesis and this fuel cell reaction.
- Carbon dioxide produced by burning fossil fuels increases carbon dioxide in the earth's atmosphere, and is considered to be a cause of global warming and extreme weather.
- Biomass is originally produced by photosynthesis of carbon dioxide in the earth's atmosphere. Since it is fixed, the carbon dioxide concentration in the atmosphere does not change substantially, and the warming problem can be avoided.
- biomass stock accumulated on the earth is about 100 times the world's annual primary energy demand, if only 1% of biomass is used every year, the energy demand will be satisfied.
- the amount of accumulated biomass is about 10 times the annual biomass production by photosynthesis, so if about 10% of the annual biomass production by photosynthesis is used, the energy demand is satisfied.
- Biomass waste such as livestock excrement, agricultural waste, garbage, and thinned wood to maintain forests, is a major cause of environmental pollution, but the energy they hold actually accounts for 1/3 of energy demand. Therefore, in addition to normal biomass, it will become a valuable energy resource in the future. Considering the above facts, the significance of the present invention is clear.
- an atomic ratio ⁇ (M / S) of 0.01 / 1-1000 / 1, preferably around 0.1 / 1-200 / 1 gives good fuel cell characteristics.
- the metal film deposited by the photodeposition method or the electrochemical deposition method gives a more favorable result.
- the photodeposition method gives good results.
- the Pt / Ti atomic ratio ⁇ in that case is typical, and 0.01 / 1-1000 / 1, preferably around 0.1 / 1-200 / 1 gives good fuel cell characteristics.
- the catalyst in the composite anode of the present invention has a band structure bending and ohmic junction that occurs in a semiconductor (electron injection from biomass to anode based on Ohm's law). This contributes to the extremely high activity and is basically different from that in the conventional fuel cell in that it is a catalyst for multi-electron decomposition and power generation that can use almost 100% of the electrons that can be provided by biomass. This shows that the operating principle of the direct fuel cell of the present invention is fundamentally different from that of the conventional one.
- the biomass or other integrated structure can be decomposed finely by mechanically and physically using the biomass as it is or using a homogenizer or the like. ⁇ It can also be used for power generation.
- a sample that is slowly decomposed it can be subjected to decomposition and power generation by this method only by immersing it in acid or alkaline water and decomposing it to some extent.
- biomass, biomass-related compounds and their waste, or other organic and inorganic substances can be decomposed (purified) by changing the semiconductor and the metal that forms a composite with the semiconductor. ) And can generate electricity at the same time.
- biomass polysaccharides such as cellulose, starch, and agarose, proteins, and polymer compounds such as lignin are relatively difficult to decompose, but in that case, if copper, nickel, osmium, etc. are used as the metal catalyst, Molecular biomass compounds can be broken down more easily. Or it can hydrolyze to low molecular weight beforehand with an acid or an alkali, and can further decompose and generate electric power by this method.
- the present inventors used a bio-photochemical cell in which a composite anode already containing a titanium dioxide porous thin film and a cathode for reducing the counter-oxygen were used, and by irradiation with ultraviolet light such as sunlight or black light, It has been clarified that these polymer compound solutions and suspended biomass solids can be easily photodegraded (see Non-Patent Document 1).
- This is a biophotochemical cell (photolysis technology) according to the proposal of the present inventors. If this technique is combined with the present invention, the above problems can be solved preferably.
- the photodegradation technology can be used to control the degree of photolysis and decompose high molecular biomass into low molecular weight compounds, and then further decompose and generate power using the method of this application.
- the photochemical cell proposed by the present inventors and the fuel cell of the present invention are combined in the same cell, and are easily decomposed by ultraviolet light to a low molecular weight, and then decomposed by the method of the present application. ⁇ It can also generate electricity.
- Such a composite anode composed of three layers of electrode base layer / porous semiconductor layer / catalyst layer for a fuel cell in the present invention can be enlarged by various devices.
- an anode electrode substrate that does not have high conductivity such as FTO the resistance increases and the current density decreases when the size is increased.
- a method for increasing the charge collection efficiency by pre-depositing a wiring such as silver or copper for collecting the charge on the FTO.
- the size can be increased easily.
- the total anode area is 8000 cm 2 , and a total output of 16 W / 8 L can be obtained.
- the fuel cell in the fuel cell reaction (basic invention) of the present invention, as an embodiment thereof, the fuel cell can be applied to metal refining. That is, in the fuel cell according to the basic invention, instead of using oxygen as an electron acceptor at the counter cathode, metal ore that is mainly produced as an oxide under anaerobic conditions, or recovered metal or scrap metal (such as scrap iron) When the oxides of these metals or their salts or complexes formed by oxidizing iron or the like are used as the electron acceptor, a pure metal can be obtained at the cathode simultaneously with the fuel cell power generation.
- fuel cell power generation is not only possible, but it does not involve melting of metals and does not require other energy such as electric power or coke, decomposition and purification of waste, simultaneous power generation, scrap metal recycling such as scrap iron (Metal refining) So-called three-stone metal refining power generation is possible. That is, as defined in claims 5 and 7.
- hydrogen production can be performed using a composite anode.
- the anode Acts as a micro fuel cell, and on the anode which has received electron injection from the fuel in the aqueous solution or aqueous suspension, the injected electrons reduce protons in the liquid phase comprising the aqueous solution or aqueous suspension.
- the composite anode constitutes a kind of micro battery.
- a microbattery is one in which one electrode material has the functions of both an anode and a cathode at the same time.
- a cell having such a function when the distance between the anode site and the cathode site is extremely short is called this. It is.
- the microcell will therefore have the functions of both an anode (accepting electrons from fuel in liquid) and a cathode (hydrogen generation by donating electrons to protons in liquid).
- the electric charges move only in the same complex and do not flow to the external circuit, no electric power is obtained, and instead, hydrogen is produced as generated energy.
- Electricity is not suitable for storage beyond a small scale, but the hydrogen produced by the method of the present invention is suitable for storage and transportation regardless of scale, and can easily be generated by a hydrogen fuel cell. It is optimal for energy demand that needs to be accompanied.
- M is the molar concentration (moldm ⁇ 3 ).
- Example 1 (Preparation of composite anode) (1) Prepare Ti-Nanoxide semiconductor paste (Solaronics, T / SP TM, average particle size 13nm, n-type titanium dioxide TiO 2 anatase content> 90%) to form porous semiconductor film did. In addition, a fluorine-doped SnO 2 conductive glass substrate (10 ⁇ / cm 2 ) (FTO) of 2 cm ⁇ 1 cm was used as the conductive electrode substrate. On the glass substrate (FTO), three 70 ⁇ m thick adhesive tapes are layered and used as a spacer (total thickness 210 ⁇ m). The semiconductor paste is applied to this 1cmx1cm area by the squeeze method and dried at room temperature. After that, sintering was performed at 450 ° C. for 30 minutes to form a TiO 2 porous semiconductor thin film on the FTO.
- Solaronics, T / SP TM average particle size 13nm, n-type titanium dioxide TiO 2 anatase content> 90%
- the thickness of the TiO 2 porous semiconductor thin film thus formed was 20 ⁇ m, and the roughness factor representing the effective surface area (ratio of the surface area of the porous TiO 2 to the apparent surface area) was about 2000.
- the platinum used was determined to be the end point by confirming that it did not remain in the solution by a visible absorption spectrum so that the entire amount of platinum could be precipitated.
- a composite anode composed of three layers of electrode-based FTO layer / porous semiconductor TiO 2 layer / Pt catalyst layer was prepared.
- the platinum layer showed a metallic luster.
- MEA membrane electrode assembly, area 1cm 2
- the glucose fuel cell was constructed by installing Ti mesh as a current collector on the air side of the MEA, and the current (I) -voltage (V) characteristics of the glucose fuel cell were measured.
- the results are shown in FIG.
- the measurement was based not on the constant potential method but on the method of measuring the current value by sweeping the potential between the two electrodes.
- the IV characteristic curve obtained in this case may have hysteresis depending on the sweep direction.
- the average value of the two curves of the anode direction sweep and the cathode direction sweep was taken as the IV characteristic.
- Example 3 Titanium dioxide (P-25) nanoparticles with an average particle size of 23 nm, surfactant, acetylacetone, and water are mixed well and kneaded thoroughly to make a paste, which is 2cm x 1cm conductive glass (FTO) After applying to the area of 1cmx1cm on top, drying at 100 ° C, repeating this, and finally sintering at 450 ° C for 30 minutes to obtain FTO / TiO 2 superporous membrane (thickness about 20 ⁇ m) It was.
- This working electrode has an effective surface area of about 2000 times the apparent area.
- Example 4 In Example 1, a titanium dioxide thin film having a thickness of 10 ⁇ m was used as the porous semiconductor thin film, and the light deposition from the FTO side was performed for the photodeposition of platinum as a catalyst.
- Example 6 A composite anode (FTO / porous titanium dioxide thin film (thickness: 10 ⁇ m) / metal layer; 1 cm 2 ) using Ni, Cu, or Os, which is much cheaper than noble metals, is used as a metal catalyst.
- Example 9 The experiment was performed in the same manner as in Example 1 except that the thickness of the porous TiO 2 thin film was changed to 10 ⁇ m.
- Isc 1.4 mA / cm 2
- Voc 0.85 V
- FF 0.24
- maximum output 0.29 m W / cm 2 were obtained.
- Isc 4.3 mA / cm 2
- Voc 1.6 V
- FF 0.25
- maximum output 1.72 m W / cm 2 were obtained. That is, when the MEA of the cathode electrode was quadrupled, the maximum output was 5.9 times.
- anode electrode base layer / porous semiconductor thin film layer / metal catalyst layer together with a cathode electrode for oxygen reduction, biomass, its waste, other organic compounds or inorganic compounds
- a composite anode of an anode electrode base layer / porous semiconductor thin film layer / metal catalyst layer together with a cathode electrode for oxygen reduction, biomass, its waste, other organic compounds or inorganic compounds
- soft path / energy-saving metal refining is possible without requiring other energy such as light irradiation.
- it is possible to construct a sustainable energy system in the near future by using biomass, its waste or other organic / inorganic compounds as fuel, and its industrial applicability is extremely high. .
- Hydrogen is an energy resource that can be easily converted into electric power by a hydrogen fuel cell, and can be easily stored and transported, and is extremely useful as a sustainable energy resource that can be directly produced from biomass.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Sustainable Energy (AREA)
- Sustainable Development (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Environmental & Geological Engineering (AREA)
- Organic Chemistry (AREA)
- Soil Sciences (AREA)
- Microbiology (AREA)
- Biochemistry (AREA)
- Inorganic Chemistry (AREA)
- Catalysts (AREA)
- Inert Electrodes (AREA)
- Fuel Cell (AREA)
Abstract
Description
乾燥したバイオマス固体や廃棄物を、単なる燃焼操作により完全分解浄化して同時に発電する方法は、従来から実施されているが、多くのバイオマス廃棄物や工場廃液は、多量の水(85%以上)を含んでいるため、単に燃焼して発電しようとしても、水分を蒸発させる潜熱の供給が必要なので、燃焼により発電しても正味のエネルギー獲得は出来ない。
しかしながら、燃料電池は、これまで水素やメタノールというごく限られたものを燃料とする場合は、一応発電が実用化されているが、それ以外の燃料、特に色々なバイオマスやバイオマス廃棄物ないしは有機・無機化合物では燃料電池による直接発電は難しい。
さらにまた、酵素や微生物、あるいは炭素担持の白金を触媒とする、バイオマス発電の研究は従来よりなされているが、それらの効率は極めて低く、実用化レベルに達した技術はこれまでなかった。
すなわち、そもそも、これらの光物理化学電池は、基本的に、光の照射を必須としているので日中のみの発電となり、夜間は全く作動しない。また、雨天や曇りの場合も発電できないため、その稼働率が天候や気象条件により大きく左右されるという根本的な問題があった。
しかして、本発明の目的は、光を照射することなく、すなわち、外部エネルギーを加えることなく、燃料電池反応により、バイオマス等の燃料の分解、浄化並びに発電するための装置及び方法を提供することである。
〔1〕
外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電する方法であって、
(a)電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードを準備し、
(b)当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させ、
(c)酸素還元用対極カソードを、当該水溶液または水性懸濁液からなる当該液相中に、または当該液相が接している気相との液相/気相界面に設置し、
(d)当該カソードが設置されている液相中,または液相/気相界面に酸素を供給、または共存させて、当該カソード上で燃料電池反応を起こさしめることを特徴とする、外部エネルギーを加えることなく当該燃料の燃料電池反応によりこれを分解浄化すると同時に発電する方法。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属の原子比が、0.01/1-1000/1である〔1〕に記載の方法。
〔3〕
複合体アノード及び酸素還元用対極カソードを備え、外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電を行う燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記酸素還元用対極カソードは、当該水溶液または水性懸濁液からなる液相中または当該液相が接している気相との液相/気相界面に設置されており、
(d)当該カソードが設置されている当該液相中に、または当該液相/気相界面中に酸素を供給、または共存させて当該カソード上で燃料電池反応を起こさしめるように構成されていることを特徴とする、外部エネルギーを加えることなく当該燃料の分解浄化をすると同時に発電する燃料電池。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である〔3〕に記載の燃料電池。
〔5〕
外部エネルギーを加えることなく燃料電池発電を行うと同時に当該カソードで純金属を得る方法であって、
(a)電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードを準備し、
(b)当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物またはそれらの混合物の何れかを燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させ、
(c)酸素還元用対極カソードを、当該水溶液または水性懸濁液からなる当該液相中に、または当該液相が接している気相との液相/気相界面に設置し、
(d)前記カソードが設置されている当該液相中または当該液相/気相界面の雰囲気を、嫌気的条件下に保つとともに、当該液相中または当該液相/気相界面に、金属鉱石、回収した金属、若しくは屑金属を酸化して生ずるそれら金属の酸化物またはそれらの塩や錯塩を電子受容体として共存させ、当該カソード上で燃料電池反応を起こさしめることを特徴とする、燃料電池発電を行うと同時に当該カソードで純金属を得る方法。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属の原子比が、0.01/1-1000/1である〔5〕に記載の方法。
〔7〕
複合体アノード及び酸素還元用対極カソードを備え、外部エネルギーを加えることなく燃料電池発電を行うと同時に当該カソードで純金属を得るための燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記酸素還元用対極カソードは、当該水溶液または水性懸濁液からなる液相中または当該液相が接触している気相との液相/気相界面に設置されており、
(d)前記カソードが設置されている当該液相または当該液相/気相界面の雰囲気を、嫌気的条件下に保つとともに、当該液相中または当該液相/気相界面に、金属鉱石、回収した金属、若しくは屑金属を酸化して生ずるそれら金属の酸化物またはそれらの塩や錯塩を電子受容体として共存させ、当該カソード上で燃料電池反応を起こさしめることを特徴とする、燃料電池発電を行うと同時に当該カソードで純金属を得るための燃料電池。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である〔7〕に記載の燃料電池。
〔9〕
複合体アノードを備え、外部エネルギーを加えることなくアノード上でミクロ燃料電池発電を行うと同時に当該アノード上で水素を得るための方法であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記複合体アノードが設置されている当該液相雰囲気を、嫌気的条件下に保つとともに、当該アノードがミクロ電池として作用し、前記水溶液または水性懸濁液中の燃料から電子注入を受けた当該アノード上で、注入された電子が当該水溶液または水性懸濁液からなる液相中のプロトンに渡って水素を発生せしめるための方法。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である〔9〕に記載の方法。
〔11〕
複合体アノードを備え、外部エネルギーを加えることなくアノード上でミクロ燃料電池発電を行うと同時に当該アノード上で水素を得るためのミクロ燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液中に浸漬されており、
(c)前記複合体アノードが設置されている液相雰囲気を、嫌気的条件下に保つとともに、当該アノードがミクロ電池として作用し、前記水溶液または水性懸濁液中の燃料から電子注入を受けた当該アノード上で、注入された電子が当該水溶液または水性懸濁液中のプロトンに渡って水素を発生せしめるためのミクロ燃料電池。
前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である〔11〕に記載のミクロ燃料電池。
5 燃料電池セル
10 金属触媒層
12 バイオマス(電子供与体)
14 電子
20 多孔質半導体層
30 電導性電極基盤層
40 酸素還元用カソード
42 外部回路(外部導線)
B ショットキー障壁
m ポテンシャル勾配
CB 電導帯
VB 荷電子帯
i 電流
まず、本発明の基礎となる材料設計方針と触媒条件は以下の発想により構成されたものである。
(2)通常、触媒(C)と基質(S、この場合は燃料)は、基質が触媒に近付いて先ず活性錯合体(C-S、一種の中間体)を作る。その後に燃料から触媒に電子移動が起こって、式(1)に示すように、C-とS+(燃料の酸化物)に分かれる。
〔1〕外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電する方法であって、
(a)電導性電極基盤層30上に多孔質半導体膜20の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜10の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノード2を準備し、
(b)当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させ、
(c)酸素還元用対極カソードを、当該水溶液または水性懸濁液からなる当該液相中に、または当該液相が接している気相との液相/気相界面に設置し、
(d)当該カソードが設置されている液相中または液相/気相界面に酸素を供給、または共存させて、当該カソード上で燃料電池反応を起こさしめることを特徴とする、外部エネルギーを加えることなく当該燃料の燃料電池反応によりこれを分解浄化すると同時に発電する方法、を提供するものであり、
または、
〔2〕複合体アノード2及び酸素還元用対極カソード40を備え、外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電を行う燃料電池であって、
(a)前記複合体アノード2は、電導性電極基盤層30上に多孔質半導体膜の層20を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層10を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記酸素還元用対極カソードは、当該水溶液または水性懸濁液からなる液相中または当該液相が接している気相との液相/気相界面に設置されており、
(d)当該カソードが設置されている液相中または液相/気相界面に酸素を供給、または共存させて当該カソード上で燃料電池反応を起こさしめるように構成されていることを特徴とする、外部エネルギーを加えることなく当該燃料の分解浄化をすると同時に発電する燃料電池、を提供するものである。(ここで符号については、図1を参照。)
本発明においては、本発明で規定する特定の複合体アノードを使用するが、当該複合体アノードは、基本的に基盤である電導性電極層、半導体層、および触媒層の3層複合体から成るものである。すなわち、より具体的には、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードである。
本発明において、電導性電極基盤層上に半導体の多孔質膜を作製する方法としては、特に限定するものでなく、例えば、次のような半導体微粒子を出発物質とする方法(塗布、焼成法など)が採用される。すなわち、まず、平均粒径が1nm~1mm、好ましくは10nm~1000nm、さらに好ましくは10nm~500nm程度の半導体微粒子(例えば二酸化チタン微粒子の場合はアナターゼ型、ルチル型、ブルッカイト型またはこれらの二者又は三者の混合型)を準備し、これに分散を促進するための界面活性剤と有機媒体および水などを少量加え、乳鉢またはボールミル等でよく練り混ぜて混合し、半導体ペーストを作製する。(半導体ペーストとしては、市販のペーストを選択使用することも可能であり、例えばTiO2ナノ粒子のペースト等を用いることもできる。)
また、電導性電極基盤としては、FTO以外に、任意のものが使用可能であり、銅、チタン、鉄、コバルト、ニッケル、亜鉛、白金、金、銀などの電導性金属や、有機電導体、高分子電導体などが使用されるが、もちろんこれらに限定されるものではない。
本発明においては、電極基盤上に、多孔質半導体薄膜層を被覆したアノード基体上に、触媒膜の層を形成して複合体アノードを作製する。触媒層の厚みは0.1nm~1mm、好ましくは0.2nm~100μm、さらに好ましくは0.4nm~30μm程度である。
この触媒膜の作製は、この多孔質半導体薄膜上に、対応する金属塩から光還元法により金属やその酸化物などを析出させるか(光析出法)、あるいは電気化学的還元法により金属やその酸化物などを析出させるなどの方法(電気化学析出法)、あるいは化学メッキ法など,それ自体公知の色々な方法が採用される。
まず、光析出法について説明する。
以下、例えば今n型半導体であるTiO2多孔質半導体薄膜上にPt膜を形成する場合を例にとり、図1を参照しながら、光析出法を説明する。
触媒として白金金属を用いるためには、例えば還元剤として3%(vol/vol)のメタノールを含む水中に、塩化白金酸カリウム、2K+[Pt(IV)Cl6]2-、を所定量溶解し、生成される複合体アノードのPt/Ti原子比φが目的の値になるようにして、このメタノールと塩化白金酸の混合水溶液中に当該TiO2多孔質半導体薄膜被覆アノード基体を浸漬し、半導体薄膜側または電導性電極側から白色光を照射する。(Pt/Ti原子比φは、後記するように、0.01/1-1000/1程度とすることが好ましい。)
つぎに電気化学析出法について説明する。
電気化学析出法を採用した場合は、多孔質半導体薄膜被覆アノード基体を、目的とする金属の塩を溶解した水溶液中に浸漬し、必要に応じて電解質を溶解させて,充分な還元電位を印加して、定電流法または定電圧法により金属をゼロ価に還元して、同時に半導体薄膜上に析出させることにより当該触媒である金属薄膜を形成することができる。このようにして、複合体アノード(電極基盤層/半導体層/触媒層)が形成される。
以上の析出メカニズムから理解されるように、Pt等の金属触媒は、多孔質半導体表面から析出するので、すなわち、ナノ構造の多孔質体の当該ナノ細孔の内表面に析出するので、半導体の金属界面に近い所ではショットキー接合(障壁)Bが形成している(図1参照)。すなわち、多孔質半導体/金属からなる複合体を形成しているものであるから、当該(多孔質半導体/金属)複合体は、いわばナノオーダーで入り組んだ界面構造を作り、半導体界面近傍ではショットキー障壁B(バンド構造の曲がり)が形成される。これに加えて、半導体が、上記のように微細なナノ構造を形成しているために、半導体と触媒の間の接合はオーミックな性質(オームの法則により電荷が輸送される)を併せ持つことになる。このため、触媒から半導体に電子がスムーズに移動し易い。このメカニズムのために、基質(分解されるべき燃料)から触媒に移動した電子が速やかに半導体層に移動し、移動した電子が続いてバンド構造の曲がりによって半導体内部に移動しやすいことにより、式(1)に示した平衡系を生成系の方にシフトする機構が働くと考えられる。
しかるに、本発明の燃料電池セルを作動させるためには、本質的に光の照射は全く不要であるという大きな特徴を有する。すなわち、後記実施例において示したように、光の照射は全く必要がないという大きな特徴を有し、光の透過に対する考慮は全く不要であるため、白金を所望量だけ多量に析出させることができる。そして、多量の白金を薄層として析出させ、金属光沢を示すような条件では触媒活性が高いので、このような白金金属結晶(微結晶の集合体の可能性もある)は白金黒凝集体より電導性が高く、白金触媒層に注入された電子が半導体層に速やかに移動することも、触媒活性の高さに大きく貢献していると考えられる。
本発明においては、かくして調製し、準備した当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させる。
通常は、当該複合体アノードは板状であり、これをバイオマスを含む液相を収容したセル容器(槽型容器)中に浸漬するが、場合によっては、当該セルの壁面(またはその一部)を複合体アノード自体で構成することもできる。その場合は、複合体アノードはバイオマス含有液相と接触することになるがこの態様であっても実施は可能である。
本発明を実施する液相について、基本的には酸性、塩基性、中性のいずれにおいても反応を実施することは可能であるが、当該反応を、効果的に進行させるためには、より好ましいpHが存在する。すなわち具体的には、反応速度は、バイオマスの種類と複合体アノードの種類に依存して変わりうるので、それに応じて好ましいpHを選択することが望ましい。特定のバイオマスと複合体アノードの種類(φ(=M/S)、M、S)に対する好ましい値は後記実施例に示したとおりである。たとえば、グルコースをバイオマス燃料とする場合は、強塩基(pH=14)程度とすることが好ましい。
本発明において、対極として用いるカソードには酸素還元触媒機能を持たせる。代表的には、水中等の液相で用いる場合には、例えば電導性電極上に白金などの酸素還元触媒を分散ないしは被覆させて用いる。対極カソードは水溶液等液相中に設置してもよいが、気相の酸素を用いると効率が高い。この理由は、酸素の水中における溶解度は低く、空気下だと酸素の分圧は1/5程度なので、空気下水中の酸素濃度(溶存酸素濃度)は0.2mM以下と少ないからである。
本燃料電池における発生理論電圧(開放起電力Voc)は、1.2V~1.3Vであるが、本発明者らが確認したところによれば、実際には1.6V以上に達することも可能であり、これにより発生電力が大幅に増大することがわかった。この理由は、カソードにおいては、液体と白金等の触媒の間に、プロトン電導体(プロトン交換体)であるナフィオン膜等の隔膜を用いているが、これが内部にプロトンを取りこんで局所的に濃縮することにより、当該隔膜中においては、液体中よりプロトン局所濃度が極めて高くなる(すなわちpHが低くなる)ので、カソードの電位が正電位側にシフトすることにより,Vocが大幅に増大することによるものと推察される。
以上のようにして作製した、電導性電極基盤層上に、多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードは、多孔質半導体、及び触媒の組み合わせに応じて、色々なバイオマスや有機・無機化合物等の燃料(以下総称して基質と称する。)を高効率で分解浄化すると同時に発電する機能を有する。
一例として、図1に、このような燃料電池反応を利用した、電極基盤層/多孔質半導体層/触媒層からなる複合体アノード2による基質の分解浄化と同時発電の機構を示した。5は燃料電池セルである。白金などの触媒層10が電子をバイオマス等の基質12から奪ってその基質を酸化的に分解し、この奪われた電子14は次いで隣接する多孔質半導体層20中の空間電荷層(バンドの曲がりm)により半導体内部に移動することにより元の基質には戻りにくいため、式(1)の平衡は生成系の方にシフトする。
バイオマスの内の特定化合物を燃料とするバイオ燃料電池としては、従来酵素燃料電池、微生物燃料電池、あるいは白金を触媒とするグルコース燃料電池が知られている。しかしながら、酵素燃料電池や微生物燃料電池、又は通常の白金触媒は、分解が可能な基質の種類が限られ、その上、通常は最初の2電子分の分解しか起こさない。即ち、グルコース基質に例を取れば、24電子供与が可能だが、その内2電子分しか分解、発電出来ないのであるという大きな問題がある。
本発明の発電方法によれば、半導体やそれと複合体を作る金属を色々変えることにより、広範なバイオマス、バイオマス関連化合物やそれらの廃棄物、あるいは他の有機物や無機物等を高効率で分解(浄化)すると同時に発電出来る。
本発明におけるこのような燃料電池用の電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードは色々な工夫により大型化できる。
その場合に、FTOなどのように電導性がそれほど高くないアノード電極基盤を用いる場合には、大型化すると抵抗が大きくなって電流密度が低下するので、それを解決するためには、多孔質半導体膜を被覆する前に、電荷収集用の銀や銅などの配線を予めFTO上に蒸着するなりして、電荷収集効率を高める工夫をすることが好ましい。
本発明の燃料電池反応(基本発明)においては、さらにその実施態様として、当該燃料電池を金属の精錬に適用することができる。
すなわち、基本的発明における燃料電池において、対極カソードで酸素を電子受容体として用いる代わりに、嫌気的条件下で、主に酸化物として産出する金属鉱石などや、回収した金属や屑金属(屑鉄などの回収金属をいう。)、鉄などを酸化して生ずるそれら金属の酸化物またはそれらの塩や錯塩などを電子受容体として用いると、燃料電池発電と同時にカソードで純金属を得ることが出来る。このようにして、単に燃料電池発電ができるばかりではなく、金属の溶融を伴わずにまた他の電力やコークスなどのエネルギーを必要としない、廃棄物の分解浄化・同時発電・屑鉄等屑金属リサイクル(金属精錬)のいわば一石3鳥型の金属精錬発電が可能である。すなわち、請求項5、7において規定したとおりである。
さらに本発明においては、複合体アノードを使用し、水素生産を行うことができる。
バイオマス含有水溶液または水性懸濁液からなる液相を収容したセル中に、本発明の複合体アノードのみを設置し、カソードは用いない条件で液相雰囲気を嫌気的条件下に保つと、当該アノードがミクロ燃料電池として作用し、水溶液または水性懸濁液中の燃料から電子注入を受けた当該アノード上で、注入された電子が当該水溶液または水性懸濁液からなる液相中のプロトンを還元して水素を発生する。この場合、当該複合体アノードは、一種のミクロ電池を構成する。ミクロ電池とは、一つの電極材料が、同時にアノード及びカソードの両方の機能を持つもので、通常はアノードサイトとカソードサイト間の距離が極めて短い場合のセルで当該機能を奏するものがこう称されるのである。当該ミクロ電池は、したがって、アノード(液中の燃料から電子の受け入れ)とカソード(液中プロトンへの電子の供与による水素発生)両方の機能を持つことになる。ただし、電荷は同じ複合体の中で移動するのみで外部回路には流れないので、電力は得られず、その代わりに発生エネルギーとして水素を生産するのである。
(複合体アノードの調製)
(1)多孔質半導体膜を形成するため、Ti-ナノキサイド半導体ペースト(ソーラロニクス社製、T/SP(商標)、平均粒径13nm、n型二酸化チタンTiO2のアナターゼ含量>90%)を準備した。また、電導性電極基盤として、2cm x1cmのフッ素ドープSnO2電導性ガラス基盤(10Ω/cm2)(FTO)を使用した。当該ガラス基盤(FTO)上に、厚さ70μmの粘着テープ3枚を重ねてスペーサー(厚さ計210μm)として用い、この1cmx1cmの面積に、上記半導体ペーストを、スクイーズ法で塗布し、室温で乾燥した後に450℃で30分焼結し、FTO上にTiO2多孔質半導体薄膜を形成させた。
実施例1に於て、原子比φ(=Pt/Ti)を0.008/1から0.50/1の間で変化させて作製したFTO/TiO2/Pt複合体アノードのグルコース燃料電池I-V特性を実施例1と同じく測定し、得られた短絡電流密度(Isc/cm2)、開放電圧(Voc)、曲線因子(FF)から最大出力(W/cm2)を求めた。(但し、TiO2膜厚は20μmとし、1 M グルコース水溶液(pH=2)を使用した。)この出力をPt/Ti比に対してプロットした結果を、表1及び図3に示す。(表1は、I-V特性と最大出力に及ぼす原子比φ(=Pt/Ti)の効果をまとめて示したものである。)
二酸化チタン(P-25)の平均粒径が23nmのナノ粒子、界面活性剤、アセチルアセトン、及び水をよく混合し、充分に練ってペ-ストを作り、これを2cmx1cmの電導性ガラス(FTO)上に1cmx1cmの面積に塗布してから、100℃で乾燥し、これを繰り返して、最後に450℃で30分焼結して、FTO/TiO2超多孔質膜(厚さ約20μm)を得た。この作用極は実効表面積が見かけ面積の約2000倍ある。このアノード基体に、実施例1と同様にしてPtを析出させ原子比φ(=Pt/TiO2(0.31/1))、複合体アノードを得た。この複合体アノードを用いて実施例1と同様にグルコース燃料電池特性を測定し、図3における同条件と同等な発電特性を得た。
実施例1において、多孔質半導体薄膜として厚さ10μmの二酸化チタン薄膜を用い、また触媒である白金の光析出にはFTO 側から光照射した他は、実施例1と同様に実験を行い、同様にグルコース燃料電池特性を測定し、Isc= 3.4 mA/cm2、 Voc= 0.62 V、 FF=0.24、最大出力0.51m W/cm2を得た。
さらに表2に示すように、:原子比φ(=Pt/Ti)が0.31/1または0.33/1において、多孔質半導体薄膜の厚み、pH、グルコース濃度を変更して実施例1と同様な実験を行った結果を表2に示した。
(表2は、TiO2 膜の厚さ,溶液 pH, 及びグルコース濃度の効果をまとめて示したものである。)
金属触媒として、貴金属よりはるかに安価なNi、Cu、または、Osを用いた複合体アノード(FTO/多孔質二酸化チタン薄膜(膜厚:10μm)/金属層;1cm2)を作製し、高分子バイオマス化合物とグルコースの分解・発電特性を調べた。その結果を表3に例示した。分解しにくい高分子バイオマスでも簡単に分解・発電することが分かる。(表3において、原子比φ(=M/Ti)は、0.3(Ni/Ti)、158(Cu/Ti)、及び0.18(Os/Ti)とした。)。
Pt 金属を触媒として原子比φ(=Pt/Ti(0.33))複合体アノードを作製し、0.01mMグルコース水溶液(5mL)を用いて、グルコース24電子の内、何電子を利用できるか調べた。5時間後に0.064Cの電荷が流れたが、これはグルコース1分子の24電子の内、平均13.3電子が流れたことに相当する(55%利用)。また、Cu金属を触媒として、(Cu/Ti=158原子比)の複合アノードを作製し、0.1mMグルコース水溶液(5mL)を用いて、同様の測定を行った。5時間後に0.801Cの電荷が流れたが、これはグルコース1分子の24電子の内、平均16.6電子が流れたことに相当する(69%利用)ことが確認された。
Pt金属を触媒として原子比φ(=Pt/Ti(0.34))、TiO2膜厚10μm)の複合体アノードを作製し、カソードは用いずに、1Mグルコース水溶液(5mL)を用いセル中は嫌気的雰囲気にすると、水素が発生した。ガスクロマトグラフィーにより水素を定性・定量した。1時間で182μLの水素が得られた。これはPt 黒を被覆したPt板を、複合体アノードの代わりに用いた時より1桁多い発生量であった。
実施例1において、多孔質TiO2薄膜の厚さを10μmとした他は、実施例1と同様に実験を行なった。カソードのMEA面積を1cm2としたセルでは、Isc= 1.4 mA/cm2、Voc= 0.85 V、FF=0.24、最大出力0.29m W/cm2を得た。これに対して、カソードのMEA面積を4cm2と4倍にしたセルでは、Isc= 4.3 mA/cm2、Voc= 1.6 V、FF=0.25、最大出力1.72m W/cm2を得た。即ち、カソード電極のMEAを4倍にした場合には、最大出力は5.9倍となった。
実施例1において、基盤電極としてFTOの代わりにチタン板(厚さ0.3mmm)を用い、また2倍量の二酸化チタンペーストを用いて、この両面に二酸化チタン薄膜(それぞれ厚さ10μm)を作製した。実施例1と同様に、Pt 層を光析出させ、またグルコースで同様に発電特性を調べた。この結果、Isc= 1.6 mA/cm2、Voc= 1.6 V、FF=0.25、最大出力0.64m W/cm2を得た。
実施例1において、TiO2膜厚を10μmとし、また百日紅の紅葉した葉をホモジナイザーで破砕して水20mLに0.2gの割合で懸濁した液を5mL用いた他は、実施例1と同様にして発電特性を調べた。その結果、Isc= 0.32mA/cm2、Voc= 0.12 V、FF=0.25、最大出力9.6μ W/cm2を得た。
Claims (12)
- 外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電を行う方法であって、
(a)電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードを準備し、
(b)当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させ、
(c)酸素還元用対極カソードを、当該水溶液または水性懸濁液からなる当該液相中に、または当該液相が接している気相との液相/気相界面に設置し、
(d)当該カソードが設置されている当該液相中、または当該液相/気相界面に酸素を供給、または共存させて、当該カソード上で燃料電池反応を起こさしめることを特徴とする、外部エネルギーを加えることなく当該燃料の燃料電池反応によりこれを分解浄化すると同時に発電する方法。 - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項1に記載の方法。
- 複合体アノード及び酸素還元用対極カソードを備え、外部エネルギーを加えることなく燃料電池反応により当該燃料の分解、浄化並びに発電を行う燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記酸素還元用対極カソードは、当該水溶液または水性懸濁液からなる液相中または当該液相が接している気相との液相/気相界面に設置されており、
(d)当該カソードが設置されている当該液相中に、または当該液相/気相界面に酸素を供給、または共存させて当該カソード上で燃料電池反応を起こさしめるように構成されていることを特徴とする、外部エネルギーを加えることなく当該燃料の分解浄化をすると同時に発電する燃料電池。 - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項3に記載の燃料電池。
- 外部エネルギーを加えることなく燃料電池発電を行うと同時に当該カソードで純金属を得る方法であって、
(a)電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードを準備し、
(b)当該複合体アノードを、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬し、または当該液相と接触させ、
(c)酸素還元用対極カソードを、当該水溶液または水性懸濁液からなる当該液相中に、または当該液相が接している気相との液相/気相界面に設置し、
(d)前記カソードが設置されている当該液相中または当該液相/気相界面の雰囲気を、嫌気的条件下に保つとともに、当該液相中または当該液相/気相界面に、金属鉱石、回収した金属、若しくは屑金属を酸化して生ずるそれら金属の酸化物またはそれらの塩や錯塩を電子受容体として共存させ、当該カソード上で燃料電池反応を起こさしめることを特徴とする、燃料電池発電を行うと同時に当該カソードで純金属を得る方法。 - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項5に記載の方法。
- 複合体アノード及び酸素還元用対極カソードを備え、外部エネルギーを加えることなく燃料電池発電を行うと同時に当該カソードで純金属を得るための燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記酸素還元用対極カソードは、当該水溶液または水性懸濁液からなる液相中または当該液相が接している気相との液相/気相界面に設置されており、
(d)前記カソードが設置されている当該液相中または当該液相/気相界面の雰囲気を、嫌気的条件下に保つとともに、当該液相中または当該液相/気相界面に、金属鉱石、回収した金属、若しくは屑金属を酸化して生ずるそれら金属の酸化物またはそれらの塩や錯塩を電子受容体として共存させ、当該カソード上で燃料電池反応を起こさしめることを特徴とする、燃料電池発電を行うと同時に当該カソードで純金属を得るための燃料電池。 - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項7に記載の燃料電池。
- 複合体アノードを備え、外部エネルギーを加えることなくアノード上でミクロ燃料電池発電を行うと同時に当該アノード上で水素を得るための方法であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記複合体アノードが設置されている当該液相雰囲気を、嫌気的条件下に保つとともに、当該アノードがミクロ電池として作用し、前記水溶液または水性懸濁液からなる液相中の燃料から電子注入を受けた当該アノード上で、注入された電子が当該水溶液または水性懸濁液からなる液相中のプロトンに渡って水素を発生せしめるための方法. - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項9に記載のミクロ燃料電池。
- 複合体アノードを備え、外部エネルギーを加えることなくアノード上でミクロ燃料電池発電を行うと同時に当該アノード上で水素を得るためのミクロ燃料電池であって、
(a)前記複合体アノードは、電導性電極基盤層上に多孔質半導体膜の層を被覆し、当該半導体層上に金属、金属酸化物、または半導体から成る触媒膜の層を形成してなる電極基盤層/多孔質半導体層/触媒層の3層から成る複合体アノードであり、
(b)当該複合体アノードは、少なくとも、バイオマス、バイオマス廃棄物、及び有機/無機化合物の何れかまたはそれらの混合物を燃料として含む水溶液または水性懸濁液からなる液相中に浸漬され、または当該液相と接触しており、
(c)前記複合体アノードが設置されている当該液相雰囲気を、嫌気的条件下に保つとともに、当該アノードがミクロ電池として作用し、前記水溶液または水性懸濁液からなる液相中の燃料から電子注入を受けた当該アノード上で、注入された電子が当該水溶液または水性懸濁液からなる液相中のプロトンに渡って水素を発生せしめるためのミクロ燃料電池. - 前記複合体アノードの触媒層を形成する金属と半導体層を形成する金属との原子比が、0.01/1-1000/1である請求項9に記載のミクロ燃料電池。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/362,837 US20140349200A1 (en) | 2011-12-06 | 2012-11-30 | Method for decomposing and purifying biomass, organic material or inorganic material with high efficiency and simultaneously generating electricity and producing hydrogen, and direct biomass, organic material or inorganic material fuel cell for said method |
JP2013548215A JP5982399B2 (ja) | 2011-12-06 | 2012-11-30 | バイオマス・有機・無機物の高効率分解浄化及び同時発電と水素生産の方法とそのためのバイオマス・有機・無機物直接燃料電池 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2011-267263 | 2011-12-06 | ||
JP2011267263 | 2011-12-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2013084825A1 true WO2013084825A1 (ja) | 2013-06-13 |
Family
ID=48574192
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2012/081121 WO2013084825A1 (ja) | 2011-12-06 | 2012-11-30 | バイオマス・有機・無機物の高効率分解浄化及び同時発電と水素生産の方法とそのためのバイオマス・有機・無機物直接燃料電池 |
Country Status (3)
Country | Link |
---|---|
US (1) | US20140349200A1 (ja) |
JP (1) | JP5982399B2 (ja) |
WO (1) | WO2013084825A1 (ja) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015066213A1 (en) * | 2013-10-29 | 2015-05-07 | Quswami, Inc. | Pre-equilibrium system and method using solid-state devices as energy converters using nano-engineered porous network materials |
JP2017154081A (ja) * | 2016-03-02 | 2017-09-07 | 日立化成株式会社 | 触媒組成物、有機廃水処理装置用電極及び有機廃水処理装置 |
CN107146849A (zh) * | 2017-06-08 | 2017-09-08 | 华中科技大学 | 一种钙钛矿太阳能电池的循环使用处理方法 |
WO2024014499A1 (ja) * | 2022-07-13 | 2024-01-18 | 国立大学法人京都大学 | 発電又は水素の製造方法及びエネルギー変換システム |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112390459B (zh) * | 2020-10-20 | 2024-02-02 | 衡阳师范学院 | 用于处理废水的电极、包括该电极的废水处理装置和废水处理方法 |
CN114551953B (zh) * | 2022-02-17 | 2024-04-26 | 广东工业大学 | 一种工业木质素的高值化利用方法 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005520304A (ja) * | 2002-03-14 | 2005-07-07 | アリゾナ ボード オブ リージェンツ | 電流発生のための酵素ベースの光電気化学電池 |
JP2005347066A (ja) * | 2004-06-02 | 2005-12-15 | Ricoh Co Ltd | 触媒電極の製造方法、触媒電極、電気化学素子、燃料電池及び電子機器 |
JP2007048572A (ja) * | 2005-08-09 | 2007-02-22 | Canon Inc | 燃料電池用膜電極接合体の製造方法 |
JP2007287542A (ja) * | 2006-04-19 | 2007-11-01 | Hiroshima Univ | 生物燃料電池用隔膜及び生物燃料電池 |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS59165379A (ja) * | 1983-03-09 | 1984-09-18 | Akira Fujishima | 光燃料電池 |
EP1289035A2 (en) * | 2001-08-29 | 2003-03-05 | Matsushita Electric Industrial Co., Ltd. | Composite electrode for reducing oxygen |
JP2006182615A (ja) * | 2004-12-28 | 2006-07-13 | Masao Kaneko | 窒素含有化合物の光分解方法 |
DE112006000541T5 (de) * | 2005-03-10 | 2008-01-03 | Ibaraki University | Phtophysikochemische Zelle |
US20080213632A1 (en) * | 2007-02-10 | 2008-09-04 | Noguera Daniel R | Light-powered microbial fuel cells |
US20110171496A1 (en) * | 2007-02-10 | 2011-07-14 | Noguera Daniel R | Light-powered microbial fuel cells |
JP4803554B2 (ja) * | 2007-07-06 | 2011-10-26 | 国立大学法人茨城大学 | バイオ光化学セルとその利用方法 |
JP5297699B2 (ja) * | 2008-06-13 | 2013-09-25 | 国立大学法人茨城大学 | バイオ光化学セル及びモジュール及び光化学的処理方法 |
WO2010014869A2 (en) * | 2008-07-31 | 2010-02-04 | The Board Of Trustees Of The University Of Illinois | Nonequilibrium chemovoltaic fuel cell |
JP5605994B2 (ja) * | 2009-02-26 | 2014-10-15 | 株式会社バイオフォトケモニクス研究所 | バイオマス・有機・無機化合物または廃棄物・廃液を高効率で光分解浄化し同時に電力を発生するバイオ光化学電池と、該バイオ光化学電池を用いて該化合物や液体を光分解浄化すると同時に電力を発生させる方法 |
WO2013006867A1 (en) * | 2011-07-07 | 2013-01-10 | Massachussetts Institute Of Technology | Methods and apparatus for ultrathin catalyst layer for photoelectrode |
-
2012
- 2012-11-30 WO PCT/JP2012/081121 patent/WO2013084825A1/ja active Application Filing
- 2012-11-30 JP JP2013548215A patent/JP5982399B2/ja not_active Expired - Fee Related
- 2012-11-30 US US14/362,837 patent/US20140349200A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005520304A (ja) * | 2002-03-14 | 2005-07-07 | アリゾナ ボード オブ リージェンツ | 電流発生のための酵素ベースの光電気化学電池 |
JP2005347066A (ja) * | 2004-06-02 | 2005-12-15 | Ricoh Co Ltd | 触媒電極の製造方法、触媒電極、電気化学素子、燃料電池及び電子機器 |
JP2007048572A (ja) * | 2005-08-09 | 2007-02-22 | Canon Inc | 燃料電池用膜電極接合体の製造方法 |
JP2007287542A (ja) * | 2006-04-19 | 2007-11-01 | Hiroshima Univ | 生物燃料電池用隔膜及び生物燃料電池 |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2015066213A1 (en) * | 2013-10-29 | 2015-05-07 | Quswami, Inc. | Pre-equilibrium system and method using solid-state devices as energy converters using nano-engineered porous network materials |
CN105723533A (zh) * | 2013-10-29 | 2016-06-29 | 库斯瓦米公司 | 使用固态装置作为能量转换器并且使用纳米工程多孔性网状材料的预平衡系统和方法 |
CN105723533B (zh) * | 2013-10-29 | 2020-01-17 | 库斯瓦米公司 | 使用固态装置作为能量转换器并且使用纳米工程多孔性网状材料的预平衡系统和方法 |
US10749049B2 (en) | 2013-10-29 | 2020-08-18 | Quswami, Inc. | Pre-equilibrium system and method using solid-state devices as energy converters using nano-engineered porous network materials |
EP3896764A1 (en) * | 2013-10-29 | 2021-10-20 | Quswami, Inc. | Pre-equilibrium system and method using solid-state devices as energy converters using nano-engineered porous network materials |
US11502207B2 (en) | 2013-10-29 | 2022-11-15 | Quswami, Inc. | Pre-equilibrium system and method using solid-state devices as energy converters using nano-engineered porous network |
JP2017154081A (ja) * | 2016-03-02 | 2017-09-07 | 日立化成株式会社 | 触媒組成物、有機廃水処理装置用電極及び有機廃水処理装置 |
CN107146849A (zh) * | 2017-06-08 | 2017-09-08 | 华中科技大学 | 一种钙钛矿太阳能电池的循环使用处理方法 |
CN107146849B (zh) * | 2017-06-08 | 2019-12-17 | 华中科技大学 | 一种钙钛矿太阳能电池的循环使用处理方法 |
WO2024014499A1 (ja) * | 2022-07-13 | 2024-01-18 | 国立大学法人京都大学 | 発電又は水素の製造方法及びエネルギー変換システム |
Also Published As
Publication number | Publication date |
---|---|
US20140349200A1 (en) | 2014-11-27 |
JPWO2013084825A1 (ja) | 2015-04-27 |
JP5982399B2 (ja) | 2016-08-31 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Lewis | Developing a scalable artificial photosynthesis technology through nanomaterials by design | |
Huang et al. | Over 1% efficient unbiased stable solar water splitting based on a sprayed Cu2ZnSnS4 photocathode protected by a HfO2 photocorrosion-resistant film | |
Chen et al. | Compositionally screened eutectic catalytic coatings on halide perovskite photocathodes for photoassisted selective CO2 reduction | |
Toe et al. | Recent advances and the design criteria of metal sulfide photocathodes and photoanodes for photoelectrocatalysis | |
Hossain et al. | Recent progress and approaches on carbon-free energy from water splitting | |
Zhang et al. | Design and Fabrication of a Dual‐Photoelectrode Fuel Cell towards Cost‐Effective Electricity Production from Biomass | |
Ren et al. | Photoactive g-C3N4/CuZIF-67 bifunctional electrocatalyst with staggered pn heterojunction for rechargeable Zn-air batteries | |
Xie et al. | Degradation of refractory organic compounds by photocatalytic fuel cell with solar responsive WO3/FTO photoanode and air-breathing cathode | |
Liu et al. | Charge Transport in Two‐Photon Semiconducting Structures for Solar Fuels | |
Suryawanshi et al. | Enhanced solar water oxidation performance of TiO2 via band edge engineering: a tale of sulfur doping and earth-abundant CZTS nanoparticles sensitization | |
JP5982399B2 (ja) | バイオマス・有機・無機物の高効率分解浄化及び同時発電と水素生産の方法とそのためのバイオマス・有機・無機物直接燃料電池 | |
Chen et al. | Review on BiVO4-based photoanodes for photoelectrochemical water oxidation: the main influencing factors | |
Yuan et al. | Pt decorated 2D/3D heterostructure of Bi2WO6 nanosheet/Cu2S snowflake for improving electrocatalytic methanol oxidation with visible-light assistance | |
Mishra et al. | A subtle review on the challenges of photocatalytic fuel cell for sustainable power production | |
Chen et al. | A solar responsive cubic nanosized CuS/Cu2O/Cu photocathode with enhanced photoelectrochemical activity | |
Wu et al. | Novel in situ synthesis of BiVO4 photocatalyst/Co3 (PO4) 2 Co-catalyst powder via the one-step solid-state process for photoelectrochemical catalyzing water oxidation | |
Queiroz et al. | Photocatalytic fuel cells: From batch to microfluidics | |
Wang et al. | A study on tandem photoanode and photocathode for photocatalytic formaldehyde fuel cell | |
Dhabarde et al. | Review of photocatalytic and photo-electrocatalytic reduction of CO2 on carbon supported films | |
Wang et al. | A ternary hybrid CuS/Cu2O/Cu nanowired photocathode for photocatalytic fuel cell | |
Qian et al. | A highly efficient photocatalytic methanol fuel cell based on non-noble metal photoelectrodes: Study on its energy band engineering via experimental and density functional theory method | |
Tilley | Will cuprous oxide really make it in water-splitting applications? | |
Esposito et al. | Hydrogen production from photo-driven electrolysis of biomass-derived oxygenates: a case study on methanol using Pt-modified WO3 thin film electrodes | |
Feng et al. | Anion-exchange membrane electrode assembled photoelectrochemical cell with a visible light responsive photoanode for simultaneously treating wastewater and generating electricity | |
Caglar et al. | Tailoring cadmium composition on titanium dioxide to achieve enhanced photocatalytic glucose fuel cell anode performance |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 12854934 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2013548215 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 14362837 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 12854934 Country of ref document: EP Kind code of ref document: A1 |