WO2014123232A1 - NOx吸蔵還元型排ガス浄化用触媒および当該触媒を用いた排ガス浄化方法 - Google Patents
NOx吸蔵還元型排ガス浄化用触媒および当該触媒を用いた排ガス浄化方法 Download PDFInfo
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- WO2014123232A1 WO2014123232A1 PCT/JP2014/052951 JP2014052951W WO2014123232A1 WO 2014123232 A1 WO2014123232 A1 WO 2014123232A1 JP 2014052951 W JP2014052951 W JP 2014052951W WO 2014123232 A1 WO2014123232 A1 WO 2014123232A1
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- WIPO (PCT)
- Prior art keywords
- exhaust gas
- catalyst
- cerium
- strontium
- oxide
- Prior art date
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- 239000003054 catalyst Substances 0.000 title claims abstract description 82
- 238000000034 method Methods 0.000 title claims description 28
- 238000000746 purification Methods 0.000 title claims description 14
- 239000007789 gas Substances 0.000 claims abstract description 66
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 57
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims abstract description 55
- 229910052712 strontium Inorganic materials 0.000 claims abstract description 52
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 claims abstract description 52
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 36
- 239000001301 oxygen Substances 0.000 claims abstract description 36
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 36
- 239000002243 precursor Substances 0.000 claims abstract description 3
- 239000002131 composite material Substances 0.000 claims description 48
- 229910000510 noble metal Inorganic materials 0.000 claims description 19
- 238000001354 calcination Methods 0.000 claims description 4
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract description 96
- 230000003197 catalytic effect Effects 0.000 abstract description 4
- 229930195733 hydrocarbon Natural products 0.000 abstract description 4
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 abstract 2
- 229910002091 carbon monoxide Inorganic materials 0.000 abstract 2
- 238000005245 sintering Methods 0.000 abstract 1
- 239000002002 slurry Substances 0.000 description 38
- 239000000843 powder Substances 0.000 description 25
- 229910000420 cerium oxide Inorganic materials 0.000 description 21
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 21
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 20
- 229910052809 inorganic oxide Inorganic materials 0.000 description 19
- IATRAKWUXMZMIY-UHFFFAOYSA-N strontium oxide Chemical compound [O-2].[Sr+2] IATRAKWUXMZMIY-UHFFFAOYSA-N 0.000 description 18
- 238000006722 reduction reaction Methods 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 238000010304 firing Methods 0.000 description 14
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 14
- 238000001179 sorption measurement Methods 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 11
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 10
- 238000001035 drying Methods 0.000 description 10
- 238000002156 mixing Methods 0.000 description 10
- 239000000203 mixture Substances 0.000 description 10
- 230000001590 oxidative effect Effects 0.000 description 9
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 7
- 229910052697 platinum Inorganic materials 0.000 description 7
- 150000003839 salts Chemical class 0.000 description 7
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 6
- 239000012736 aqueous medium Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 229910052761 rare earth metal Inorganic materials 0.000 description 6
- 229910052703 rhodium Inorganic materials 0.000 description 6
- 239000010948 rhodium Substances 0.000 description 6
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 6
- 238000003860 storage Methods 0.000 description 6
- 229910052783 alkali metal Inorganic materials 0.000 description 5
- 150000001340 alkali metals Chemical class 0.000 description 5
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 5
- 150000001342 alkaline earth metals Chemical class 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 239000010970 precious metal Substances 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 4
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 4
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 4
- 229910052878 cordierite Inorganic materials 0.000 description 4
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 4
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 4
- UFQXGXDIJMBKTC-UHFFFAOYSA-N oxostrontium Chemical compound [Sr]=O UFQXGXDIJMBKTC-UHFFFAOYSA-N 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- 150000001242 acetic acid derivatives Chemical class 0.000 description 3
- 239000003463 adsorbent Substances 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- -1 cerium salt Chemical class 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003426 co-catalyst Substances 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 150000004679 hydroxides Chemical class 0.000 description 3
- 238000005470 impregnation Methods 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000002823 nitrates Chemical class 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- 238000001238 wet grinding Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 2
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- BDAGIHXWWSANSR-NJFSPNSNSA-N hydroxyformaldehyde Chemical compound O[14CH]=O BDAGIHXWWSANSR-NJFSPNSNSA-N 0.000 description 2
- 229910052741 iridium Inorganic materials 0.000 description 2
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 2
- CHWRSCGUEQEHOH-UHFFFAOYSA-N potassium oxide Chemical compound [O-2].[K+].[K+] CHWRSCGUEQEHOH-UHFFFAOYSA-N 0.000 description 2
- 229910001950 potassium oxide Inorganic materials 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910000018 strontium carbonate Inorganic materials 0.000 description 2
- 159000000008 strontium salts Chemical class 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000004580 weight loss Effects 0.000 description 2
- 239000010457 zeolite Substances 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 229910052693 Europium Inorganic materials 0.000 description 1
- 229910002060 Fe-Cr-Al alloy Inorganic materials 0.000 description 1
- 229910052688 Gadolinium Inorganic materials 0.000 description 1
- 229910052689 Holmium Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 229910052772 Samarium Inorganic materials 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910052771 Terbium Inorganic materials 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- CSSYLTMKCUORDA-UHFFFAOYSA-N barium(2+);oxygen(2-) Chemical class [O-2].[Ba+2] CSSYLTMKCUORDA-UHFFFAOYSA-N 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- KOPBYBDAPCDYFK-UHFFFAOYSA-N caesium oxide Chemical class [O-2].[Cs+].[Cs+] KOPBYBDAPCDYFK-UHFFFAOYSA-N 0.000 description 1
- 229910001942 caesium oxide Inorganic materials 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- YWEUIGNSBFLMFL-UHFFFAOYSA-N diphosphonate Chemical compound O=P(=O)OP(=O)=O YWEUIGNSBFLMFL-UHFFFAOYSA-N 0.000 description 1
- KBQHZAAAGSGFKK-UHFFFAOYSA-N dysprosium atom Chemical compound [Dy] KBQHZAAAGSGFKK-UHFFFAOYSA-N 0.000 description 1
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 1
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- KJZYNXUDTRRSPN-UHFFFAOYSA-N holmium atom Chemical compound [Ho] KJZYNXUDTRRSPN-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910001392 phosphorus oxide Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- VXNYVYJABGOSBX-UHFFFAOYSA-N rhodium(3+);trinitrate Chemical compound [Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VXNYVYJABGOSBX-UHFFFAOYSA-N 0.000 description 1
- 229910052701 rubidium Inorganic materials 0.000 description 1
- IGLNJRXAVVLDKE-UHFFFAOYSA-N rubidium atom Chemical compound [Rb] IGLNJRXAVVLDKE-UHFFFAOYSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- KZUNJOHGWZRPMI-UHFFFAOYSA-N samarium atom Chemical compound [Sm] KZUNJOHGWZRPMI-UHFFFAOYSA-N 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- GZCRRIHWUXGPOV-UHFFFAOYSA-N terbium atom Chemical compound [Tb] GZCRRIHWUXGPOV-UHFFFAOYSA-N 0.000 description 1
- VSAISIQCTGDGPU-UHFFFAOYSA-N tetraphosphorus hexaoxide Chemical compound O1P(O2)OP3OP1OP2O3 VSAISIQCTGDGPU-UHFFFAOYSA-N 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
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- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/91—NOx-storage component incorporated in the catalyst
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/92—Dimensions
- B01D2255/9207—Specific surface
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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- B01J35/30—
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Definitions
- the present invention relates to a NOx occlusion reduction type exhaust gas purification catalyst and an exhaust gas purification method using the catalyst. More specifically, the present invention relates to an exhaust gas purification catalyst for the purpose of removing nitrogen oxides (NOx) among harmful components contained in exhaust gas of gasoline engines and diesel engines, and an exhaust gas purification method using the catalyst. Is.
- NOx in the atmosphere causes photochemical smog and acid rain. For this reason, NOx emissions from automobiles equipped with an internal combustion engine, which is one of NOx generation sources, have become a social problem. For this reason, in the future, studies are being made in the direction of stricter regulations regarding NOx emissions. However, since diesel engines and gasoline lean burn engines are lean combustion with a large amount of oxygen, it is difficult to reduce and remove NOx. For this reason, development of NOx occlusion reduction type exhaust gas purifying catalysts characterized by storing NOx in an oxidizing atmosphere and reducing and purifying NOx occluded in a reducing atmosphere has been underway.
- Cerium oxide is very useful for NOx occlusion reduction type exhaust gas purification catalyst, NOx adsorption is performed by the oxygen occlusion / release function even in a low temperature region of 300 ° C. or less, and cerium oxide itself works as a NOx adsorbent. Is described. (Patent Document 1).
- Patent Document 2 describes that the catalytic activity can be increased by raising the temperature of the metal catalyst using the reaction heat of cerium oxide having an oxygen storage / release function.
- cerium oxide has excellent NOx adsorption performance even in a low temperature region of 300 ° C. or lower, it has an oxygen storage / release function, so when shifting from an oxidizing atmosphere to a reducing atmosphere, cerium oxide releases oxygen. Therefore, there is a drawback that the NOx reduction reaction is suppressed.
- cerium oxide works to absorb oxygen, so that there is a disadvantage that the initial NOx adsorption and occlusion performance is particularly poor.
- An object of the present invention is to provide a type exhaust gas purification catalyst.
- the present inventors have used NOx, which is a harmful component contained in exhaust gas, by using a composite oxide of strontium and cerium as a catalyst active component in the catalyst. As a result, the present invention has been completed.
- NOx can be efficiently removed from CO, HC and NOx which are harmful components contained in the exhaust gas.
- FIG. The horizontal axis is the diffraction angle (2 ⁇ ), and the vertical axis is the intensity.
- the first invention of the present invention is an exhaust gas purifying catalyst characterized in that a composite oxide of strontium and cerium is used as a catalytic active component.
- a composite oxide of strontium and cerium is used as a catalytic active component.
- the present invention is not limited to the following inference. That is, in the composite oxide of strontium and cerium, cerium apparently exists in an electron excess state (reduced state) due to the electron donating action of strontium. On the other hand, since oxygen itself has a strong electron withdrawing property, electrons on cerium are strongly attracted to the oxygen side. The bond between cerium and oxygen tends to be stronger than cerium alone. Oxygen is strongly bonded to cerium, so even if the exhaust gas changes from an oxidizing atmosphere to a reducing atmosphere and oxygen is easily released as a gas, oxygen is not easily released as a gas, and the exhaust gas maintains a reducing atmosphere. It becomes easy. It is considered that reducing agents such as HC and CO in the exhaust gas can easily react with NOx in the exhaust gas because the oxygen in the exhaust gas is small, and NOx is reduced to nitrogen.
- reducing agents such as HC and CO in the exhaust gas can easily react with NOx in the exhaust gas because the oxygen in the exhaust gas is small, and NOx is reduced
- Cerium oxide having an oxygen storage function is indispensable for an exhaust gas treatment catalyst that is used in a state where the exhaust gas alternately repeats an oxidizing atmosphere and a reducing atmosphere.
- the cerium oxide has the above-mentioned drawbacks in a situation where the exhaust gas temperature changes, particularly in a low temperature range where the exhaust gas temperature is 300 ° C. or lower.
- the composite oxide of strontium and cerium according to the present invention is used as a catalytically active component.
- the average particle size is not particularly limited.
- the ratio of strontium oxide (SrO) to cerium oxide (CeO 2 ) in the composite oxide of strontium and cerium may be any ratio as long as the composite oxide can be formed, but is preferably SrO / CeO 2. Is 0.2 to 2.0 (molar ratio), more preferably 0.33 to 1.2, and most preferably 0.9 to 1.1. With such a ratio, the effect of the composite oxide as described above appears effectively, and the composite oxide can be easily formed.
- the complex oxide of strontium and cerium is preferably a perovskite complex oxide represented by SrCeO 3 .
- the composite oxide of strontium and cerium preferably a perovskite type composite oxide represented by SrCeO 3
- the diffraction angle (2 ⁇ ) has 4 peaks in total, 3 peaks near 29 ° and 1 peak near 42 °. It can be confirmed that the sample is a composite oxide of strontium and cerium, preferably a perovskite type composite oxide represented by SrCeO 3 .
- the complex oxide preferably has an oxygen adsorption amount (mL) of 1 mL or less per 1 g of the sample (catalyst) at a catalyst inlet gas temperature of 400 ° C. (atmosphere temperature) by pulse analysis. That is, it is preferable that the composite oxide of strontium and cerium adsorbs 1.0 mL or less of oxygen per gram in a 400 ° C. atmosphere.
- the oxygen adsorption amount (mL) per 1 g of the sample (catalyst) at a catalyst inlet gas temperature of 400 ° C. (atmosphere temperature) is more preferably 0.5 mL or less, and further preferably 0.2 mL or less.
- the lower limit is not particularly limited, but is 0 mL or more, and preferably exceeds 0 mL.
- the oxygen storage capacity (Oxygen Storage Capacity; OSC) may be activated to suppress the NOx reduction reaction in a reducing atmosphere.
- the pulse analysis method is a gas mixture containing oxygen after a sample weighed in advance is placed in a reaction tube where the temperature can be adjusted, the sample is reduced with hydrogen gas, and an inert gas is sufficiently passed over the sample. Is introduced in a predetermined amount (oxygen pulse). The introduction operation is continued until the amount of oxygen introduced into the sample is equal to the amount of oxygen downstream of the sample. Initially, the amount of oxygen downstream of the sample is smaller than the amount of oxygen introduced into the sample, and the difference is the amount of oxygen adsorbed on the sample. The total amount of oxygen adsorbed in each pulse is the oxygen adsorption amount of 1 g of the sample (catalyst).
- the method for producing the composite oxide of strontium and cerium according to the present invention is not particularly limited.
- a strontium source for example, a water salt of strontium
- a cerium source for example, a water salt of cerium
- Method coprecipitation method
- strontium source for example, strontium salt
- cerium source for example, cerium salt
- a method (mixing method) in which each solid source can be mixed, dried and fired can be used, and a mixing method is preferred.
- the mixing method is preferably a method in which a strontium source (for example, a strontium salt) and a cerium source (for example, a cerium salt) are mixed and pulverized dry or wet (for example, using water), and then dried and fired.
- the mixing ratio of the strontium source and the cerium source is not particularly limited, but the mixing ratio is such that the ratio (molar ratio) of strontium oxide (SrO) and cerium oxide (CeO 2 ) is as described above. It is preferable.
- the amount of water added is also not particularly limited, but considering the ease of wet grinding and the ease of drying, the total weight of the strontium source and cerium source About 100 to 200 parts by weight of water is preferably added with respect to 100 parts by weight.
- Calcination may be performed in one step or in multiple steps.
- the firing temperature is not particularly limited, but is preferably 600 ° C. or higher, more preferably 700 to 1200 ° C., and still more preferably 800 to 1150 ° C.
- the firing time is not particularly limited, but is preferably 0.5 to 20 hours, more preferably 1.0 to 15 hours. Under such conditions, a composite oxide of strontium and cerium can be efficiently produced.
- the firing method and conditions for firing in multiple stages are not particularly limited. For example, in the case of firing in two stages, temporary firing is performed at a temperature of 300 ° C. or more and less than 600 ° C. for 0.25 to 10 hours. Then, after obtaining a mixture containing strontium and cerium (for example, a mixture of strontium oxide and cerium oxide), the mixture is preferably fired at a temperature of 600 ° C. or more for 0.5 hour or more. That is, the composite oxide of strontium and cerium is preferably obtained by firing a precursor (a mixture of a strontium source and a cerium source) at 600 ° C. or higher.
- a precursor a mixture of a strontium source and a cerium source
- drying when mixing (wet mixing) using water, it is preferable to dry a mixture beforehand and to remove a water
- the drying conditions in this case are not particularly limited as long as a sufficient amount of water can be removed, and may be appropriately selected according to the amount of water mixed.
- cerium source hydroxides, nitrates, acetates, carbonates, oxide powders and the like can be used, and oxides are preferred.
- strontium source hydroxides, carbonates, nitrates, acetates and the like can be used, and carbonates are preferred.
- the NOx occlusion reduction type exhaust gas purification catalyst is basically formed by coating a carrier used for a catalyst with the composite oxide of strontium and cerium as a catalyst component.
- a refractory inorganic oxide and / or a promoter component can also be included.
- a noble metal can be added for the purpose of NOx reduction or oxidation of HC, CO and particulates. That is, it is preferable that the NOx occlusion reduction type exhaust gas purifying catalyst of the present invention further contains a noble metal.
- a carrier usually used as an exhaust gas purification carrier in the field can be used without limitation, but a three-dimensional structure is preferably used.
- a heat-resistant carrier such as a honeycomb carrier can be used.
- an integrally molded type integral weir body
- a monolith carrier, a metal honeycomb carrier, a plugged honeycomb carrier such as a diesel particulate filter, a punching metal, or the like is preferably used.
- the three-dimensional integrated structure is not necessarily required, and for example, a pellet carrier can be used.
- the monolithic carrier what is usually referred to as a ceramic honeycomb carrier may be used, and cordierite, mullite, ⁇ -alumina, silicon carbide, silicon nitride and the like are particularly preferable. Particularly preferred are cordierite carriers.
- an integrated structure using an oxidation-resistant heat-resistant metal including stainless steel, Fe—Cr—Al alloy, or the like is used.
- These monolithic carriers are manufactured by an extrusion molding method or a method of winding and hardening a sheet-like element.
- the shape of the through hole may be any of a hexagon (honeycomb), a quadrangle, a triangle, or a corrugation (corrugation).
- a cell density (number of cells / unit cross-sectional area) of 100 to 1200 cells / in 2 is sufficient, preferably 200 to 900 cells / in 2, more preferably 250 to 600 cells / in 2. .
- the method for supporting the catalyst of the present invention on the three-dimensional structure is not particularly limited. For example, a method such as a wash coat can be used.
- the amount of the composite oxide of strontium and cerium used is not particularly limited, but is preferably 10 to 450 g, more preferably 10 to 200 g, and still more preferably 20 to 100 g per liter (L) of the catalyst. If the amount exceeds this amount, the catalyst mechanical strength decreases, which is not preferable.
- the refractory inorganic oxide is not particularly limited as long as it is usually used as a catalyst carrier.
- aluminum oxide (Al 2 O 3 ) such as activated alumina such as ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, ⁇ -alumina; silicon oxide (silica) (SiO 2 ); Titanium oxide (titania) (TiO 2 ); Zirconium oxide (zirconia) (ZrO 2 ); Phosphorus oxide (P 2 O 5 ); Phosphate zeolite; or a composite oxide thereof such as alumina-titania composite oxide, alumina -Zirconia composite oxide, titania-zirconia composite oxide, ceria-zirconia composite oxide, zeolite, silica-alumina, etc.
- aluminum oxide, silicon oxide (silica), phosphorus oxide, titanium oxide, oxidation Zirconium and ceria-zirconia composite oxides are preferred, silicon oxide (silica), dioxide Koniumu, aluminum oxide, ceria - zirconia composite oxide are more preferable, zirconium oxide, aluminum oxide, ceria - zirconia composite oxide, powder of activated alumina is more preferable.
- single oxides such as ⁇ -alumina, silica, titania and zirconia, and composite oxides thereof are used.
- the above refractory inorganic oxides may be used alone or in the form of a mixture of two or more.
- oxides may be used in the form of oxides as described above, but those that can form oxides by heating may also be used.
- halides such as hydroxides, nitrates and chlorides, acetates, sulfates and carbonates of the above aluminum, silicon, titanium, zirconium and phosphorus can be used.
- the size of these refractory inorganic oxides is not particularly limited, but is usually a powder having an average particle diameter (diameter) of 2 to 60 ⁇ m, preferably 5 to 50 ⁇ m, more preferably 5 to 40 ⁇ m. Further, the BET specific surface area of the refractory inorganic oxide is preferably 50 to 750 m 2 / g, more preferably 150 to 750 m 2 / g, from the viewpoint of supporting the catalytically active component.
- the amount of the refractory inorganic oxide used is not particularly limited, but is preferably 10 to 450 g per liter (L) of the catalyst, more The amount is preferably 30 to 400 g, more preferably 40 to 200 g, and particularly preferably 50 to 100 g. If it is less than 10 g, the catalyst component (for example, a composite oxide of strontium and cerium or a noble metal described in detail below) cannot be sufficiently dispersed, and the durability may not be sufficient.
- the catalyst component for example, a composite oxide of strontium and cerium or a noble metal described in detail below
- the promoter preferably contains at least one element selected from the group consisting of alkali metals, alkaline earth metals, and rare earth elements.
- the composite oxide of strontium and cerium is not included in the promoter component. That is, the catalyst of the present invention further contains at least one element (promoter component) selected from the group consisting of alkali metals, alkaline earth metals, and rare earth elements (excluding composite oxides of strontium and cerium). It is preferable.
- the catalyst of the present invention is an oxide of at least one element selected from the group consisting of alkali metals, alkaline earth metals and rare earth elements, more preferably oxides of alkali metals and alkaline earth metals.
- alkali metals alkaline earth metals and rare earth elements
- the catalyst of the present invention is an oxide of at least one element selected from the group consisting of alkali metals, alkaline earth metals and rare earth elements, more preferably oxides of alkali metals and alkaline earth metals.
- An oxide of a rare earth element selected from the group consisting of europium, gadolinium, terbium, dysprosium, holmium, erbium,
- sodium oxide, potassium oxide, barium oxide, strontium oxide, cerium oxide and lanthanum oxide More preferred are potassium oxide, barium oxide, strontium oxide and cerium oxide.
- these things may be used independently or may be used with the form of 2 or more types of mixtures.
- the use amount (supported amount) of the promoter component is not particularly limited, but is 5 to 450 g, more preferably 5 to 200 g, still more preferably 5 to 70 g, and most preferably 10 to 50 g per liter (L) of the catalyst. is there. In addition, when using the same element as the said complex oxide, it is the amount divided separately. In addition, when using a some promoter component, the usage-amount (supporting amount) of the said promoter component means the total amount of the usage-amount (supporting amount) of each promoter component.
- the noble metal is not particularly limited, and examples thereof include platinum, palladium, rhodium, iridium, ruthenium, etc., preferably platinum, palladium, rhodium, iridium are used, More preferred are platinum, palladium, and rhodium.
- the noble metal may be used alone or in the form of a mixture of two or more.
- the amount of precious metal used is not particularly limited, and can be appropriately selected depending on the concentration of harmful components to be purified (removed). Specifically, the precious metal can be used in an amount of preferably 0.1 to 15 g, more preferably 0.5 to 10 g, per liter (L) of the catalyst. Within such a range, harmful components can be sufficiently removed (purified).
- the usage-amount (supporting amount) of the said noble metal means the total amount of the usage-amount (supporting amount) of each noble metal.
- the precious metal can be precious metal black, but it can be coated with other oxides to increase the metal surface area. In particular, it is preferable to coat the refractory inorganic oxide having a large specific surface area.
- Catalyst preparation method Any method may be used as long as the composite oxide of strontium and cerium is included.
- the composite oxide of strontium and cerium, and if necessary, a promoter component, a noble metal, and fire resistance An inorganic oxide (for example, a refractory inorganic oxide supporting a noble metal) is placed in an aqueous medium, and then a slurry is obtained using a wet pulverizer such as a ball mill, and the honeycomb is immersed in the slurry to remove excess slurry.
- a wet pulverizer such as a ball mill
- the composite oxide of strontium and cerium and the refractory inorganic oxide are placed in an aqueous medium and then made into a slurry using a wet pulverizer such as a ball mill.
- the honeycomb is immersed in the slurry, the excess slurry is removed, dried or fired, and then immersed in an aqueous solution containing a water-soluble salt of a noble metal and a water-soluble salt of a promoter component, and then an excess liquid.
- a composite oxide of strontium and cerium, a co-catalyst component, and a refractory inorganic oxide are placed in an aqueous medium, followed by wet grinding such as a ball mill.
- a slurry using a machine immersing the honeycomb in the slurry, removing excess slurry, drying or firing, then immersing in an aqueous solution containing a noble metal salt, removing excess liquid, drying and firing to obtain a catalyst
- a wet pulverizer such as a ball mill
- the honeycomb is immersed in the slurry, and an excess slurry
- a method of obtaining a catalyst by immersing in an aqueous solution containing a noble metal salt and a salt of a promoter component, removing excess liquid, drying and calcining, and (5) the strontium and selenium
- the honeycomb is immersed in the slurry, excess slurry
- a method of obtaining a catalyst by immersing, removing excess slurry, drying and firing (layered structure), (8) a refractory inorganic oxide supporting a noble metal is placed in an aqueous medium, and then a wet pulverizer such as a ball mill is used. Use the slurry, soak the honeycomb in the slurry, remove the excess slurry, dry or fire, then soak in the slurry containing the co-catalyst component, strontium and cerium composite oxide, remove the excess slurry, and dry And a method of obtaining a catalyst by firing (layered structure).
- space velocity of the exhaust gas is 10,000 ⁇ 300,000h -1, preferably 10,000 ⁇ 100,000 h -1.
- the exhaust gas treatment temperature may be from about 200 ° C. to 900 ° C. or more, preferably from 200 ° C. to 700 ° C.
- the target exhaust gas is exhaust gas from internal combustion engines such as diesel engines and gasoline engines.
- the exhaust gas exhibits an excellent effect when it repeats an oxidizing atmosphere and a reducing atmosphere.
- the exhaust gas purifying catalyst of the present invention can be disposed in the exhaust gas passage to treat the exhaust gas, and can be installed under the floor of the automobile from the vicinity of the engine manifold. Furthermore, it can be used in combination with a catalyst having other functions. For example, a catalyst / adsorbent having a hydrocarbon adsorption function, a diesel particulate filter, a three-way catalyst, and an oxidation catalyst.
- a catalyst / adsorbent having a hydrocarbon adsorption function, a diesel particulate filter, a three-way catalyst, and an oxidation catalyst.
- a preferred combination condition is that the purification catalyst of the present invention is installed on the upstream side of the exhaust gas, a hydrocarbon adsorbent or a diesel particulate filter is installed on the downstream side, or a three-way catalyst or an oxidation catalyst is installed on the upstream side of the exhaust gas.
- the exhaust gas purifying catalyst of the present invention is installed on the downstream side of the exhaust gas.
- Example 1 Aqueous slurry A was obtained by mixing 161.5 g of cerium oxide, 138.51 g of strontium carbonate, and 360 g of water, followed by wet grinding with a ball mill for 14 hours. Next, after drying at 120 ° C. for 12 hours to completely remove moisture, the powder was fired at 500 ° C. for 1 hour to obtain powder A (a mixture of strontium oxide and cerium oxide).
- the ratio (SrO / CeO 2 ) (molar ratio) of strontium oxide (SrO) to cerium oxide (CeO 2 ) in the obtained powder A is about 1.
- the powder A was fired at 1100 ° C. for 10 hours to obtain a powder B (complex oxide of strontium and cerium).
- the ratio (SrO / CeO 2 ) (molar ratio) of strontium oxide (SrO) to cerium oxide (CeO 2 ) in the obtained powder B (complex oxide of strontium and cerium) is about 1. is there.
- This catalyst was supported with 1 g / L of platinum, 0.15 g / L of rhodium, 48 g / L of a composite oxide (powder) of strontium and cerium and 65 g / L of alumina on the support.
- the oxygen adsorption amount of the finished catalyst (A) thus obtained was 0.01 mL / g (oxygen adsorption amount (mL) per 1 g of catalyst).
- Example 1 A finished catalyst (X) was obtained in the same manner as in Example 1 except that Powder A was not calcined at 1100 ° C. in Example 1 (that is, Powder A was used instead of Powder B).
- Powder A was used instead of Powder B.
- platinum 1 g / L, rhodium 0.15 g / L, powder A 48 g / L and alumina 65 g / L were supported on the honeycomb carrier.
- the oxygen adsorption amount of the finished catalyst (X) thus obtained was 1.48 mL / g.
- aqueous slurry C was obtained by mixing 5.19 g of powder C, 21 g of powder D, 30 g of cerium oxide, 25.62 g of strontium carbonate, 29.59 g of heat-resistant activated alumina (average particle size 30 ⁇ m) and 142 g of water.
- a commercially available cordierite monolith honeycomb carrier 400 cells / square inch, diameter 24 mm, length 66 mm, volume 0.030 L was immersed, and excess slurry was blown off with compressed air. Next, it was dried for 10 minutes at 150 ° C. until the weight loss disappeared, and further calcined at 500 ° C.
- a finished catalyst (Y).
- platinum 1 g / L, rhodium 0.15 g / L, strontium oxide 25.62 g / L, cerium oxide 30 g / L and alumina 65 g / L were supported on the support.
- the oxygen adsorption amount of the finished catalyst (Y) thus obtained was 1.39 mL / g.
- the completed catalyst (A) prepared in Example 1 and the completed catalysts (X) and (Y) prepared in Comparative Examples 1 and 2 were evaluated.
- the evaluation was performed by installing each catalyst in a stainless steel reaction tube, flowing a gas of condition 1 (oxidizing atmosphere) shown in Table 1 for 55 seconds, and then flowing a gas of condition 2 (reducing atmosphere) for 5 seconds.
- the average NOx purification rate of each atmosphere and oxidizing atmosphere was measured.
- the gas temperature was evaluated at a catalyst inlet temperature of 200 ° C., 300 ° C., 400 ° C., and 500 ° C.
- the NOx purification rate was calculated from the following formula. The results are shown in Table 2.
- the NOx reduction performance in the reducing atmosphere of the finished catalyst (A) containing the composite oxide of strontium and cerium used in Example 1 is 30 to 40% from the low temperature to the high temperature of the exhaust gas as compared with the catalysts of Comparative Examples 1 and 2. It showed that it was so high.
- the present invention can be used for exhaust gas treatment, and in particular, since exhaust gas can reduce NOx in an oxygen-excess atmosphere, it can be used for automobile exhaust gas treatment.
Abstract
Description
ストロンチウムとセリウムとの複合酸化物における酸化ストロンチウム(SrO)と酸化セリウム(CeO2)との比率は複合酸化物を形成することができれば何れの比率であっても良いが、好ましくはSrO/CeO2が0.2~2.0(モル比)、更に好ましくは0.33~1.2、最も好ましくは0.9~1.1である。このような比率であれば、上記したような複合酸化物の効果が有効に現れ、また、複合酸化物を容易に形成できる。
NOx吸蔵還元型排ガス浄化用触媒は、基本的には触媒成分として当該ストロンチウムとセリウムとの複合酸化物を触媒用に用いられる担体に被覆して形成されるものである。好ましくは耐火性無機酸化物および/または助触媒成分を含むこともできる。更にNOx還元又はHC、CO及びパティキュレートを酸化することを目的として貴金属を添加することもできる。すなわち、本発明のNOx吸蔵還元型排ガス浄化用触媒は、貴金属をさらに含むことが好ましい。
当該ストロンチウムとセリウムとの複合酸化物が含まれれば何れの方法であっても良いが、(1)当該ストロンチウムとセリウムとの複合酸化物と、必要であれば、助触媒成分、貴金属および耐火性無機酸化物(例えば、貴金属を担持した耐火性無機酸化物)とを、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥、焼成して触媒得る方法、(2)当該ストロンチウムとセリウムとの複合酸化物と、耐火性無機酸化物とを、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、貴金属の水溶性塩と助触媒成分の水溶性塩を含む水溶液に浸した後、余剰の液を除き、乾燥、焼成し触媒を得る方法、(3)当該ストロンチウムとセリウムとの複合酸化物と、助触媒成分と、耐火性無機酸化物とを、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、貴金属塩を含む水溶液に浸し、余剰の液を除き、乾燥、焼成して触媒を得る方法、(4)当該ストロンチウムとセリウムとの複合酸化物と、耐火性無機酸化物を、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、貴金属塩と助触媒成分の塩を含む水溶液に浸し、余剰の液を除き、乾燥、焼成して触媒を得る方法、(5)当該ストロンチウムとセリウムとの複合酸化物を水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、助触媒成分と貴金属を担持した耐火性無機酸化物とを含むスラリーに浸し、余剰のスラリーを除き、乾燥、焼成して触媒得る方法(層状構造)、(6)当該ストロンチウムとセリウムとの複合酸化物と助触媒成分とを水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、貴金属を担持した耐火性無機酸化物とを含むスラリーに浸し、余剰のスラリーを除き、乾燥、焼成して触媒得る方法(層状構造)(7)助触媒成分と、貴金属を担持した耐火性無機酸化物とを、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、当該ストロンチウムとセリウムとの複合酸化物を含むスラリーに浸し、余剰のスラリーを除き、乾燥、焼成して触媒得る方法(層状構造)、(8)貴金属を担持した耐火性無機酸化物とを、水媒体に入れた後、ボールミルなどの湿式粉砕機を用いてスラリーとし、当該スラリーにハニカムを浸し、余剰のスラリーを除き、乾燥又は焼成した後、助触媒成分とストロンチウムとセリウムとの複合酸化物とを含むスラリーに浸し、余剰のスラリーを除き、乾燥、焼成して触媒得る方法(層状構造)などである。
上記方法において、排ガスの空間速度(S.V.)は10,000~300,000h-1、好ましくは10,000~100,000h-1である。
セリウム酸化物161.5gと炭酸ストロンチウム138.51gと水360gとを混合し、ボールミルにより14時間湿式粉砕して、水性スラリーAを得た。次に120℃で12時間乾燥し、水分を完全に除去した後、500℃で1時間焼成して、粉体A(ストロンチウムの酸化物とセリウムの酸化物との混合物)を得た。ここで、得られた粉体Aにおける酸化ストロンチウム(SrO)と酸化セリウム(CeO2)との比率(SrO/CeO2)(モル比)は、約1である。
実施例1において粉体Aを1100℃で焼成しない(即ち、粉体Bの代わりに粉体Aを使用した)こと以外は、実施例1と同様にして完成触媒(X)を得た。この触媒は、ハニカム担体に対して、白金1g/L、ロジウム0.15g/L、粉体A48g/L及びアルミナ65g/Lが担持されていた。
粉体C5.19g、粉体D21g、酸化セリウム30g、炭酸ストロンチウム25.62g、耐熱性活性アルミナ(平均粒径30μm)29.59gと水142gを混合し、水性スラリーCを得た。このスラリーCに、市販のコージェライト質モノリスハニカム担体(400セル/平方インチ、直径24mm、長さ66mm、体積0.030L)を浸漬し、余剰のスラリーを圧縮空気により吹き飛ばした。次に、150℃で水分減量がなくなるまで10分間乾燥し、さらに電気炉にて500℃で1時間焼成して、完成触媒(Y)を得た。この触媒は、担体に対して、白金1g/L、ロジウム0.15g/L、酸化ストロンチウム25.62g/L、酸化セリウム30g/L及びアルミナ65g/Lが担持されていた。
上記実施例1で調製した完成触媒(A)、及び比較例1、2で調製した完成触媒(X)、(Y)を評価した。評価はステンレス製反応管に各触媒を設置し、表1に示す条件1(酸化雰囲気)のガスを55秒流した後、条件2(還元雰囲気)のガスを5秒流すことを繰り返し、当該還元雰囲気と酸化雰囲気個々の平均NOx浄化率を測定した。ガス温度は触媒入口温度で200℃、300℃、400℃、500℃の場合について評価した。NOx浄化率は下記の式より算出した。結果は表2に示した。
Claims (5)
- ストロンチウムとセリウムとの複合酸化物を含む、NOx吸蔵還元型排ガス浄化用触媒。
- 当該ストロンチウムとセリウムとの複合酸化物が400℃雰囲気で1g当たり1.0mL以下の酸素を吸着する、請求項1に記載のNOx吸蔵還元型排ガス浄化用触媒。
- 当該ストロンチウムとセリウムとの複合酸化物が前駆体を600℃以上で焼成することで得られるものである、請求項1または2に記載のNOx吸蔵還元型排ガス浄化用触媒。
- 貴金属をさらに含む、請求項1~3のいずれか1項に記載のNOx吸蔵還元型排ガス浄化用触媒。
- 請求項1~4のいずれか1項に記載の排ガス処理用触媒を用いて排ガスを処理することを有する排ガス処理方法。
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102017123538A1 (de) | 2016-10-14 | 2018-04-19 | Toyota Jidosha Kabushiki Kaisha | Abgasreinigungsvorrichtung für einen Verbrennungsmotor |
JP2019112973A (ja) * | 2017-12-21 | 2019-07-11 | 株式会社豊田中央研究所 | 内燃機関の排気浄化装置 |
Families Citing this family (2)
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EP3560576B1 (en) * | 2018-04-24 | 2021-01-13 | Toyota Jidosha Kabushiki Kaisha | Use of a nitrogen oxide storage material and exhaust gas purification method |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10128118A (ja) * | 1996-09-09 | 1998-05-19 | Hino Motors Ltd | 窒素酸化物除去触媒及びその製造方法 |
JP2001179092A (ja) * | 1999-12-24 | 2001-07-03 | Mitsui Mining & Smelting Co Ltd | 排ガス浄化用触媒 |
JP2010069380A (ja) * | 2008-09-17 | 2010-04-02 | Daihatsu Motor Co Ltd | 排ガス浄化用触媒 |
JP2012055842A (ja) | 2010-09-09 | 2012-03-22 | Toyota Motor Corp | 排ガス浄化用触媒 |
JP2012125767A (ja) * | 2007-01-25 | 2012-07-05 | Nissan Motor Co Ltd | 排気ガス浄化用触媒及びその製造方法 |
JP5122196B2 (ja) | 2007-07-17 | 2013-01-16 | 本田技研工業株式会社 | NOx浄化触媒 |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5850458A (ja) * | 1981-09-22 | 1983-03-24 | Toyo Soda Mfg Co Ltd | ガルバニ−電池式湿度センサ− |
JPH01148711A (ja) * | 1987-12-03 | 1989-06-12 | Mitsubishi Electric Corp | 超電導体の製造方法 |
GB9020568D0 (en) * | 1990-09-20 | 1990-10-31 | Rover Group | Supported palladium catalysts |
JP3271782B2 (ja) * | 1992-03-09 | 2002-04-08 | 大阪瓦斯株式会社 | 窒素酸化物の除去剤および除去方法 |
CN100457238C (zh) * | 1998-02-22 | 2009-02-04 | 无锡威孚力达催化净化器有限责任公司 | 用于净化内燃机尾气和/或工业废气的催化剂及其制备 |
EP1201302B1 (en) * | 2000-02-22 | 2007-08-08 | Mazda Motor Corporation | Exhaust gas purifying catalyst and production method for exhaust gas purifying catalyst |
JP4590733B2 (ja) * | 2000-02-22 | 2010-12-01 | マツダ株式会社 | 排気ガス浄化用触媒及び該触媒による排気ガス浄化方法 |
CN1091396C (zh) * | 2000-06-21 | 2002-09-25 | 中国科学院兰州化学物理研究所 | 用于净化废气的催化剂 |
JP2002079106A (ja) * | 2000-06-29 | 2002-03-19 | Mazda Motor Corp | 排気ガス浄化用触媒、及び排気ガス浄化装置 |
JP3818062B2 (ja) | 2001-01-10 | 2006-09-06 | トヨタ自動車株式会社 | 排気ガス浄化用触媒 |
US7648785B2 (en) * | 2004-09-17 | 2010-01-19 | Eaton Corporation | Clean power system |
JP5106748B2 (ja) * | 2004-11-08 | 2012-12-26 | 株式会社キャタラー | 排ガス浄化用触媒 |
JP4835193B2 (ja) | 2006-02-20 | 2011-12-14 | マツダ株式会社 | ディーゼルパティキュレートフィルタ |
JP5190196B2 (ja) | 2006-12-01 | 2013-04-24 | Dowaエレクトロニクス株式会社 | 排ガス浄化触媒用複合酸化物および排ガス浄化触媒、並びにディーゼル排ガス浄化用フィルター |
EP1952876A1 (en) | 2007-01-25 | 2008-08-06 | Nissan Motor Co., Ltd. | Exhaust gas purifying catalyst and manufacturing method thereof |
JP2009022929A (ja) * | 2007-07-23 | 2009-02-05 | Nissin Electric Co Ltd | 亜酸化窒素の分解触媒、それを備える亜酸化窒素の分解装置およびそれを用いる亜酸化窒素の分解方法 |
JP5168193B2 (ja) * | 2008-03-24 | 2013-03-21 | 国立大学法人 熊本大学 | 粒子状物質燃焼触媒およびその製造方法並びに排気ガス浄化用フィルター |
EP2363206B1 (en) * | 2008-11-21 | 2018-08-15 | Nissan Motor Co., Ltd. | Particulate substance removing material, particulate substance removing filter catalyst using particulate substance removing material, and method for regenerating particulate substance removing filter catalyst |
US8337791B2 (en) | 2008-12-03 | 2012-12-25 | Daiichi Kigenso Kagaku Kogyo Co., Ltd. | Exhaust gas purification catalyst, exhaust gas purification apparatus using the same and exhaust gas purification method |
JP4998579B2 (ja) * | 2010-04-01 | 2012-08-15 | トヨタ自動車株式会社 | 排気浄化触媒 |
-
2014
- 2014-02-07 EP EP14748868.8A patent/EP2954950B1/en active Active
- 2014-02-07 JP JP2014560826A patent/JP6106197B2/ja active Active
- 2014-02-07 US US14/766,618 patent/US10226755B2/en active Active
- 2014-02-07 CN CN201480007803.8A patent/CN104981289A/zh active Pending
- 2014-02-07 WO PCT/JP2014/052951 patent/WO2014123232A1/ja active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10128118A (ja) * | 1996-09-09 | 1998-05-19 | Hino Motors Ltd | 窒素酸化物除去触媒及びその製造方法 |
JP2001179092A (ja) * | 1999-12-24 | 2001-07-03 | Mitsui Mining & Smelting Co Ltd | 排ガス浄化用触媒 |
JP2012125767A (ja) * | 2007-01-25 | 2012-07-05 | Nissan Motor Co Ltd | 排気ガス浄化用触媒及びその製造方法 |
JP5122196B2 (ja) | 2007-07-17 | 2013-01-16 | 本田技研工業株式会社 | NOx浄化触媒 |
US8425869B2 (en) | 2007-07-17 | 2013-04-23 | Honda Motor Co., Ltd. | NOx purifying catalyst |
JP2010069380A (ja) * | 2008-09-17 | 2010-04-02 | Daihatsu Motor Co Ltd | 排ガス浄化用触媒 |
JP2012055842A (ja) | 2010-09-09 | 2012-03-22 | Toyota Motor Corp | 排ガス浄化用触媒 |
Non-Patent Citations (1)
Title |
---|
See also references of EP2954950A4 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102017123538A1 (de) | 2016-10-14 | 2018-04-19 | Toyota Jidosha Kabushiki Kaisha | Abgasreinigungsvorrichtung für einen Verbrennungsmotor |
US10612438B2 (en) | 2016-10-14 | 2020-04-07 | Toyota Jidosha Kabushiki Kaisha | Exhaust purification apparatus for internal combustion engine |
JP2019112973A (ja) * | 2017-12-21 | 2019-07-11 | 株式会社豊田中央研究所 | 内燃機関の排気浄化装置 |
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