CN105792929A - Exhaust-gas purifying catalyst and method for producing same - Google Patents
Exhaust-gas purifying catalyst and method for producing same Download PDFInfo
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- CN105792929A CN105792929A CN201480066003.3A CN201480066003A CN105792929A CN 105792929 A CN105792929 A CN 105792929A CN 201480066003 A CN201480066003 A CN 201480066003A CN 105792929 A CN105792929 A CN 105792929A
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- Prior art keywords
- catalyst
- catalyst layer
- zirconium
- oxide
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- 239000003054 catalyst Substances 0.000 title claims abstract description 183
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 36
- 239000010410 layer Substances 0.000 claims abstract description 78
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims abstract description 29
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims abstract description 24
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 24
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 21
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 21
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052809 inorganic oxide Inorganic materials 0.000 claims abstract description 17
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 15
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 14
- 239000010948 rhodium Substances 0.000 claims abstract description 14
- 239000002131 composite material Substances 0.000 claims abstract description 13
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000002356 single layer Substances 0.000 claims abstract description 4
- 239000007789 gas Substances 0.000 claims description 39
- 238000000034 method Methods 0.000 claims description 36
- 150000001553 barium compounds Chemical class 0.000 claims description 24
- 239000011268 mixed slurry Substances 0.000 claims description 21
- 238000006555 catalytic reaction Methods 0.000 claims description 18
- 239000002245 particle Substances 0.000 claims description 16
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 14
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 150000002940 palladium Chemical class 0.000 claims description 10
- 150000003283 rhodium Chemical class 0.000 claims description 10
- 150000003755 zirconium compounds Chemical class 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 8
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 8
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 8
- 239000002912 waste gas Substances 0.000 claims description 7
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 6
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 6
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 6
- 239000000969 carrier Substances 0.000 claims description 5
- UJVRJBAUJYZFIX-UHFFFAOYSA-N nitric acid;oxozirconium Chemical compound [Zr]=O.O[N+]([O-])=O.O[N+]([O-])=O UJVRJBAUJYZFIX-UHFFFAOYSA-N 0.000 claims description 5
- 238000000746 purification Methods 0.000 claims description 5
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Inorganic materials [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- DUFCMRCMPHIFTR-UHFFFAOYSA-N 5-(dimethylsulfamoyl)-2-methylfuran-3-carboxylic acid Chemical compound CN(C)S(=O)(=O)C1=CC(C(O)=O)=C(C)O1 DUFCMRCMPHIFTR-UHFFFAOYSA-N 0.000 claims description 3
- 239000002243 precursor Substances 0.000 claims description 3
- CSSYLTMKCUORDA-UHFFFAOYSA-N barium(2+);oxygen(2-) Chemical compound [O-2].[Ba+2] CSSYLTMKCUORDA-UHFFFAOYSA-N 0.000 claims description 2
- CAGZNTXUZUOERQ-UHFFFAOYSA-N [O-2].O.[Ce+3] Chemical compound [O-2].O.[Ce+3] CAGZNTXUZUOERQ-UHFFFAOYSA-N 0.000 claims 1
- 230000015572 biosynthetic process Effects 0.000 claims 1
- 239000012018 catalyst precursor Substances 0.000 claims 1
- 229910052751 metal Inorganic materials 0.000 abstract description 83
- 239000002184 metal Substances 0.000 abstract description 83
- 239000006185 dispersion Substances 0.000 abstract description 10
- 150000002739 metals Chemical class 0.000 abstract description 4
- 238000002156 mixing Methods 0.000 abstract description 3
- 239000003513 alkali Substances 0.000 abstract description 2
- 230000003197 catalytic effect Effects 0.000 description 82
- 238000012360 testing method Methods 0.000 description 24
- 150000003839 salts Chemical class 0.000 description 23
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 19
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 18
- 229910002091 carbon monoxide Inorganic materials 0.000 description 17
- 239000002002 slurry Substances 0.000 description 14
- 230000000694 effects Effects 0.000 description 10
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 9
- 238000004458 analytical method Methods 0.000 description 7
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 7
- 159000000009 barium salts Chemical class 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000000996 additive effect Effects 0.000 description 6
- 230000015556 catabolic process Effects 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000006731 degradation reaction Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 6
- 229910000510 noble metal Inorganic materials 0.000 description 6
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 6
- 229910052788 barium Inorganic materials 0.000 description 5
- 238000001354 calcination Methods 0.000 description 5
- 239000002244 precipitate Substances 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 239000002253 acid Substances 0.000 description 4
- 238000004453 electron probe microanalysis Methods 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 230000001629 suppression Effects 0.000 description 4
- 239000000654 additive Substances 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 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 3
- 238000003860 storage Methods 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- ITHZDDVSAWDQPZ-UHFFFAOYSA-L barium acetate Chemical compound [Ba+2].CC([O-])=O.CC([O-])=O ITHZDDVSAWDQPZ-UHFFFAOYSA-L 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 239000003599 detergent Substances 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 229910052746 lanthanum Inorganic materials 0.000 description 2
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 150000002927 oxygen compounds Chemical class 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 239000006228 supernatant Substances 0.000 description 2
- 229910052727 yttrium Inorganic materials 0.000 description 2
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 0.000 description 2
- IVORCBKUUYGUOL-UHFFFAOYSA-N 1-ethynyl-2,4-dimethoxybenzene Chemical compound COC1=CC=C(C#C)C(OC)=C1 IVORCBKUUYGUOL-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 241000607479 Yersinia pestis Species 0.000 description 1
- GTLIZBSOPDMZRP-UHFFFAOYSA-N [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[OH4+2].[Zr+4] Chemical compound [O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O.[OH4+2].[Zr+4] GTLIZBSOPDMZRP-UHFFFAOYSA-N 0.000 description 1
- 230000004931 aggregating effect Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229960004424 carbon dioxide Drugs 0.000 description 1
- 229910002090 carbon oxide Inorganic materials 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 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 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 150000004692 metal hydroxides Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000004745 nonwoven fabric Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 238000010200 validation analysis Methods 0.000 description 1
- -1 wherein Substances 0.000 description 1
Classifications
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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
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/101—Three-way catalysts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/56—Platinum group metals
- B01J23/63—Platinum group metals with rare earths or actinides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/0234—Impregnation and coating simultaneously
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/10—Noble metals or compounds thereof
- B01D2255/102—Platinum group metals
- B01D2255/1023—Palladium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/10—Noble metals or compounds thereof
- B01D2255/102—Platinum group metals
- B01D2255/1025—Rhodium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/204—Alkaline earth metals
- B01D2255/2042—Barium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/206—Rare earth metals
- B01D2255/2061—Yttrium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/206—Rare earth metals
- B01D2255/2063—Lanthanum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/20—Metals or compounds thereof
- B01D2255/209—Other metals
- B01D2255/2092—Aluminium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/40—Mixed oxides
- B01D2255/407—Zr-Ce mixed oxides
-
- 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
-
- B01J35/19—
-
- B01J35/391—
-
- B01J35/40—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/04—Mixing
-
- 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
- F01N2370/00—Selection of materials for exhaust purification
- F01N2370/02—Selection of materials for exhaust purification used in catalytic reactors
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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
Abstract
The purpose of the invention is to provide an exhaust-gas purifying catalyst containing a plurality of catalyst metals, with the catalyst layer thereof comprising a single layer, wherein the degree of dispersion of the catalyst metals is high and the catalyst performance thereof is also high. An additional purpose of the invention is to provide a method for producing this catalyst, which can be definitively supported, without using an alkali solution. The invention pertains to an exhaust-gas purifying catalyst obtained by forming a single catalyst layer on a support body, wherein: the catalyst layer is obtained by supporting palladium and rhodium on a carrier obtained by mixing an inorganic oxide such as alumina and a ceria-zirconia composite oxide with one another; and the ratio (SZr/SCe) of the zirconium concentration to the cerium concentration in the surface of the catalyst layer is 1.05-6.0 times the ratio (CZr/CCe) of the zirconium concentration to the cerium concentration at the interface between the catalyst layer and the support body.
Description
Technical field
The present invention relates to exhaust gas purifying catalyst and manufacture method thereof, particularly relate to be suitable as purifying in waste gas
The catalyst of the three-way catalyst of carbonoxide, Hydrocarbon and nitrogen oxides.
Background technology
As exhaust gas purifying catalyst, utilize the harmful substance i.e. carbon monoxide (CO) contained in waste gas, nytron
Thing (HC) and nitrogen oxides (NOx) aoxidize or reduce and carry out the three-way catalyst purified simultaneously.About the composition of this catalyst,
As the carrier of supported catalyst metal, outside the general metal oxide carrier such as alumina, also use Ceria-zirconia multiple
Close the storage oxygen species such as oxide.In catalyst containing storage oxygen species (OSM), oxygen absorption based on OSM is utilized to discharge ability,
Can easily and efficiently carry out the redox reaction of 3 kinds of harmful substances (CO, HC and NOx).It addition, in three-way catalyst, as
Catalytic metal is many containing noble metals such as platinum of more than two kinds, palladium, rhodiums.For these noble metals, each it is prone to having of purification
Pest matter is different, therefore by combining multiple different noble metal, it is possible to effectively remove 3 kinds of harmful substances.
Here, containing multiple noble metal as the catalyst of catalytic metal becomes problem, there is catalytic metal
Between alloying time, it is impossible to give full play of intended catalyzed performance.Therefore, in the case of applying multiple catalytic metal, logical
It is commonly formed and makes catalyst layer be the structure being made up of multilamellar and be respectively configured the waste gas purification of catalytic metal at each catalyst layer and urge
Agent.Such as, recorded in patent documentation 1 and be configured with palladium at the first coating, be configured with platinum and rhodium at the second coating
Exhaust gas purifying catalyst.
But, the catalyst being so formed with multiple catalysts layer needs the catalysis formed when the making of catalyst
Oxidant layer carries out the manufacturing processes such as the preparation of slurry, the coating on supporter and calcining respectively, and by single catalyst layer structure
The catalyst become is compared, and manufacturing process's number increases, and becomes the catalyst that cost is high.
In this context, as using multiple catalytic metal and the catalyst making catalyst layer be simple layer, specially
Profit document 2 is recorded following catalyst: use rhodium and palladium as catalytic metal, use 2 kinds of Ceria-zirconia composite oxygen
Compound is as carrier.Described catalyst suppresses catalytic metal by loading different catalytic metals respectively on 2 kinds of carriers
Alloying.
As for the method that manufactures exhaust gas purifying catalyst discussed above, it is however generally that apply following method:
The slurry comprise carrier adds after catalytic metal salt, utilizes aqueous slkali to make the pH of slurry increase so that catalytic metal with
The form of insoluble compound separates out.By utilizing aqueous slkali to make the interpolation due to catalytic metal salt and pH in acid slurry
Rise, thus make catalytic metal be fixed on carrier.About this point, patent documentation 2 is recorded use tetraethyl hydrogen-oxygen
Change the ammonium (TEAH) carrying method as the catalytic metal of aqueous slkali.Specifically, in order to load difference respectively on 2 kinds of carriers
Catalytic metal, first, the slurry comprising the first carrier adds rhodium salt and during in highly acid, adds TEAH and make on pH
Rise, so that rhodium separates out.Then, the second carrier is made to be suspended in this slurry, in interpolation palladium salt again in acid slurry
Middle interpolation TEAH and make pH again increase, make palladium separate out.
Prior art literature
Patent documentation
Patent documentation 1: Japanese Unexamined Patent Publication 11-151439 publication
Patent documentation 2: Japanese Unexamined Patent Application Publication 2010-521302 publication
Summary of the invention
Invent problem to be solved
But, the catalyst of patent documentation 2 does not have sufficiently clean when as the actual application of exhaust gas purifying catalyst
Change performance, thus expect the further raising of catalysis activity.Particularly as the manufacture method of described catalyst, by using
The catalyst that aqueous slkali makes catalytic metal separate out is difficult to become the catalyst that catalysis activity is high.
Therefore, it is an object of the invention to provide useless comprise that multiple catalytic metal and catalyst layer be made up of simple layer
Gas cleaning catalyst has the catalyst of higher purifying property.The present invention also aims to offer can not use alkali molten
Reliably make manufacture method that catalytic metal precipitate on carrier as the manufacture method of described catalyst in the case of liquid.
For the method solving problem
To this end, the exhaust gas purifying catalyst that catalytic performance is good is conducted in-depth research by the present inventors, and have in mind
In the catalytic metal load condition to carrier.Now, for the catalyst of above-mentioned patent documentation 2, it is contemplated to: by urging
Change the interim load of metal, utilize the pH adjustment etc. of aqueous slkali, the coming off of the catalytic metal separated out occurs, is reconfigured at.Specifically
For, it is believed that in the stage for making the interpolation of catalytic metal salt that the second catalytic metal separates out, interpolation aqueous slkali, first analyse
The first the catalytic metal dissolution gone out on carrier, is reconfigured on another carrier.Then, aqueous slkali is used and the catalysis that separates out
Metal precipitates with the form of hydroxide, easily be combined with each other and coarsening.Thus, the present inventors thinks, by suppression
Being reconfigured at of above-mentioned catalytic metal, while the precipitation of the form of hydroxide reliably supported catalyst metal, it is possible to realize
The further raising of catalytic performance, thus obtained the exhaust gas purifying catalyst of the present invention.As a result, obtained catalyst is entered
Go labor, it was found that when the zirconium concentration of catalyst layer surface is high with the ratio of cerium concentration (zirconium concentration/cerium concentration),
Catalytic metal load condition on carrier becomes reliable, thus contemplates the exhaust gas purifying catalyst of the present invention.
That is, the present invention relates to a kind of exhaust gas purifying catalyst, it is to form single catalyst layer on supporter to form
Exhaust gas purifying catalyst, wherein, catalyst layer be by aluminium oxide, cerium oxide, zirconium oxide at least any one is constituted
The supported on carriers that mixes of inorganic oxide and Ceria-zirconia composite oxides have the catalyst layer of palladium and rhodium,
And the zirconium concentration (S on the surface of catalyst layerZr) and cerium concentration (SCe) ratio (SZr/SCe) relative to catalyst layer with support
Zirconium concentration (the C at the interface of bodyZr) and cerium concentration (CCe) ratio (CZr/CCe) it is 1.05～6.0.
In the exhaust gas purifying catalyst of the present invention, catalyst layer is simple layer, and supported on carriers have palladium and rhodium this 2
Plant as catalytic metal.And, the catalyst of the present invention is characterised by following aspect: (zirconium is dense for the ratio of zirconium concentration and cerium concentration
Degree/cerium concentration) catalyst layer near surface higher than with the near interface of supporter.Catalyst for such present invention
For, the dispersion of catalytic metal is high, and catalytic performance (particularly CO oxidability, NOx reducing power) is high.
About zirconium/cerium concentration (SZr/SCe、CZr/CCe), the value (S on the surface of catalyst layerZr/SCe) relative to catalyst layer
The value (C at the interface with supporterZr/CCe)((SZr/SCe)/(CZr/CCe)) be 1.05～6.0, be preferably 1.1～5.0, especially
It is preferably 1.1～3.5.If less than 1.05, then there is the tendency that the durability of catalytic metal becomes insufficient, if more than 6.0, then
There is the tendency that the dispersion of catalytic metal reduces.
Zirconium/cerium concentration ratio (S as the surface of catalyst layerZr/SCe), from catalyst layer surface until with support
The place that locates of the depth direction of the catalyst layer till the interface of body, can apply from the most surface of catalyst layer to propping up
The analysis result at the place that locates of the degree of depth of support body side 5～10 μm.It addition, as the interface with supporter of catalyst layer
Zirconium/cerium concentration (CZr/CCe), can apply from the interface of supporter to the place that locates of the degree of depth of face side 5～10 μm
Analysis result.Above zirconium concentration/cerium concentration (SZr/SCe、CZr/CCe) electron ray microscopic analyzer (EPMA) can be passed through
Measure.
Hereinafter, each structure of the exhaust gas purifying catalyst of the present invention is described in detail.
As carrier, it is used together the Ceria-zirconia as storage oxygen species with the inorganic oxide such as aluminium oxide and is combined
Oxide (CZ).About CZ, preferably Zirconium oxide relative to the ratio (zirconium oxide/cerium oxide) of cerium oxide it is by quality ratio
95/5～5/95.It addition, as additive, the alkaline earth elements such as the oxide of rare earth element, magnesium, calcium such as yttrium, lanthanum, praseodymium can be contained
Oxide in more than a kind.The content of CZ elects 20～80 mass % as relative to the Functionality, quality and appealing design of catalyst entirety.
As inorganic oxide, it is possible to use more than any one in aluminium oxide, cerium oxide, zirconium oxide etc., the most excellent
Select aluminium oxide.As aluminium oxide, preferably gama-alumina, it is also possible to doped with rare earth elements such as yttrium, lanthanum, praseodymiums.Inorganic oxide
Content elects 20～80 mass % as relative to the Functionality, quality and appealing design of catalyst layer entirety.
As catalytic metal, comprise both palladium and rhodium.The load capacity of catalytic metal relative to carrier be preferably 0.1～
2.5 mass %.If less than 0.1 mass %, then be difficult to obtain sufficient catalytic performance, if more than 2.5 mass %, then become without
Ji and easily cause the gathering of catalytic metal.
In catalyst layer, in addition to above-mentioned carrier and catalytic metal, further preferably contain barium compound.If zirconium/cerium ratio is upper
In the range of stating and possibly together with the catalyst of barium, then it is easily made into CO oxidizing force and the higher catalyst of NOx reducing power.As barium
Compound, preferably optionally from barium sulfate, brium carbonate, Barium monoxide.These barium salts are many with sulfur in untapped exhaust gas purifying catalyst
Presented in acid barium or brium carbonate, after catalyst uses, how to be present in catalyst layer with brium carbonate or barytic form
In.
Relative to the whole compositions in catalyst layer are converted into the quality of oxide, the content of barium compound is to be converted into
Barytic quality meter is preferably 0.1～10 mass %, more preferably 1.0～6.0 mass %.If less than 0.1 mass %, then difficult
To obtain the additive effect of barium compound.The upper limit of content is without limiting especially, even if adding more than 10 mass %, barium chemical combination
The additive effect of thing is also difficult to improve further.The particle diameter of barium compound is preferably 0.01 μm less than 2.0 μm.Even if grain
Footpath is less than 0.01 μm, it is also difficult to expect the further raising of additive effect, easily forms the poly-of barium compound in catalyst layer
Glomeration.In the case of forming such aggregation block, the adhesiveness of catalyst layer declines.If the particle diameter of barium compound is 2.0 μm
Above, then catalytic performance is difficult to improve.Shape of particle is the most spherical or tabular.
The exhaust gas purifying catalyst of the present invention is propping up of being made up of structures such as ceramic honeycomb, metal beehive, non-woven fabrics
The catalyst of catalyst layer discussed above is possessed on support body.
As the method for the exhaust gas purifying catalyst manufacturing the present invention discussed above, following manufacturer can be applied
Method: be included in by the carrier paste of Ceria-zirconia composite oxides and inorganic oxide suspendible add palladium salt and
Rhodium salt and prepare the operation of the mixed slurry of the precursor as catalyst layer and being coated by mixed slurry and formed on supporter
The operation of the catalyst precarsor layer of monolayer, at the carrier paste in the stage of the interpolation palladium salt of operation and rhodium salt preparing mixed slurry
It is contained within zirconium compounds.
In the manufacture method of the present invention, adding as the palladium salt of catalytic metal salt with in the stage of rhodium salt, having at suspendible
The slurry of carrier is contained within zirconium compounds as additive.The catalyst obtained by the preparation method of the present invention is that catalysis activity is high
Catalyst, particularly can observe that the purifying rate of purification composition (CO, HC, NOx) reaches the temperature (T of 50% effectively50) low
Wen Hua.This is considered owing to palladium and rhodium are difficult on carrier carry out being reconfigured at thus reliably carry out the reason loaded.Catalytic gold
Genus can so reach reliable load condition be considered due to, it is possible to suppression as use aqueous slkali load time be catalyzed
Metal precipitates with the form of hydroxide, and catalytic metal is carried on carrier in the form of an ion.And, it is not easy to as catalytic gold
Belong to the catalysis caused by combination between producing like that due to catalytic metal hydroxide when occurring and precipitate with the form of hydroxide
The coarsening of metal.
Hereinafter, the manufacture method of the present invention is described in detail.Using the Ceria-zirconia combined oxidation as carrier
Thing and inorganic oxide are suspended in water, prepare carrier paste.The addition of each carrier is whole relative to obtained catalyst layer
Body, preferably to make inorganic oxide be 20～70 mass %, makes Ceria-zirconia composite oxides be 20～70 mass %.System
During standby carrier paste, preferably carry out pulverizing, mixing and make carrier become the uniform and particle size distribution of regulation.Particle size distribution is preferably
0.1～20 μm.It should be noted that Ceria-zirconia composite oxides and inorganic oxide can apply with as waste gas
Cleaning catalyst be formed in the material that kind described above, particle diameter are same.
When preparing above-mentioned carrier paste, preferably mix together with Ceria-zirconia composite oxides and inorganic oxide
Cooperation carries out slurried for the insoluble barium compound of additive.By being also added with insoluble barium chemical combination in addition to zirconium compounds
Thing, it is easy to obtain the higher catalyst of catalytic performance.As long as insoluble barium compound is added, then before adding catalytic metal
No matter before and after the preparation of carrier paste, can add at any time, but preferably when preparing carrier paste and as carrier
Ceria-zirconia composite oxides, inorganic oxide is added together.Owing to insoluble barium compound is particle shape,
Therefore by carrying out pulverizing together with identical emboliform carrier, mix and slurried, prepared sizes distribution is thus tended to all
Even mixed slurry.
As insoluble barium compound, preferably barium sulfate or brium carbonate, particularly preferred barium sulfate.Relative to by obtained
Whole compositions in catalyst layer are converted into the quality of oxide, and the addition of insoluble barium compound is barytic to be converted into
Quality meter, preferably 1.0～10 mass %.Here, in the present invention, as barium compound, apply insoluble compound.Solvable
Property barium compound there is the surface differential at Ceria-zirconia composite oxides dissipate thus hinder and absorb the ability releasing oxygen
Tendency, and be prone to segregation, it is difficult to it is uniformly dispersed in catalyst layer.On the other hand, applying as in the present invention
In the case of insoluble barium compound, it is possible to keep shape of particle in carrier paste, thus without multiple at Ceria-zirconia
Close oxide surface and hinder the ability absorbing releasing oxygen, it is possible to make barium composition be uniformly dispersed in catalyst layer.Need explanation
, as insoluble barium compound, can apply same at particle diameter described above with the structure as exhaust gas purifying catalyst
The material of sample.
Then, adding the palladium salt as catalytic metal salt and rhodium salt in above-mentioned carrier paste, preparation becomes catalyst layer
The mixed slurry of precursor.As catalytic metal salt, it is possible to use the water miscible compound that nitrate, acetate etc. are general,
It is preferably nitrate.Scope that the addition of each catalytic metal salt preferably makes palladium be 0.1～2.5 mass % relative to carrier, make
Rhodium is the scope of 0.1～0.5 mass %.
As adding opportunity of zirconium compounds, preferably when prepared by above-mentioned mixed slurry and add palladium salt and rhodium salt it
Before.More than any one in the preferred zirconyl nitrate of zirconium compounds, zirconium acetate, zirconia sol, particularly preferred zirconyl nitrate.Phase
For the whole compositions in obtained catalyst layer are converted into the quality of oxide, the addition of zirconium compounds is preferably to change
It is counted as zirconic quality meter to reach the mode of 0.5～5.0 mass % and be added.If this addition, then can obtain on
The catalyst of the Zr/Ce ratio stated, it is easy to the dispersion becoming catalytic metal in obtained catalyst is high, catalytic performance is the highest
Catalyst.
In the manufacture method of the present invention, by adding zirconates, it is possible to unlike the manufacture method described in patent documentation 2
Catalytic metal is made to be fixed on carrier in the case of using aqueous slkali, therefore, it is possible to suppression catalytic metal is with the form of hydroxide
Precipitation.The pH adding the mixed slurry after catalytic metal salt is the value changed according to the addition of catalytic metal salt, but
Under the implementation condition of the present invention how in the range of about 2.5～about 6.0, particularly many about 3.0～about 5.0.According to this
Bright, after adding catalytic metal salt, it is possible to make catalytic metal reliably precipitate on carrier in the case of without aqueous slkali.
In the case of the precipitation of catalytic metal is insecure, in the work making the mixed slurry being added with catalytic metal be dried, calcine
In sequence, catalytic metal falls off sometimes, even if but the catalytic metal separated out by the manufacture method of the present invention doing
During dry, calcining etc., coming off of catalytic metal also will not occur.
For mixed slurry made above, preferably with respect to mixed slurry so that the whole catalyst in slurry become
The solid constituent amount divided reaches the mode of 20～50 mass % and is prepared.Obtained mixed slurry is being applied on supporter
And after forming the catalyst precarsor layer of monolayer, carry out calcining and forming catalyst layer such that it is able to manufacture exhaust gas purifying catalyst.
The calcining heat of supporter is preferably 400～700 DEG C.When mixed slurry is applied on supporter, it is possible to use acetic acid, water
The adjustment of slurry viscosity is carried out Deng regulator.But, when adjusting viscosity, to avoid adding there is the dispersibility making catalytic metal
The aqueous slkali of the tendency declined.The supporter being coated with mixed slurry is dried the most before calcination.Baking temperature is preferably
90～200 DEG C.
Invention effect
The exhaust gas purifying catalyst of the present invention is while utilizing the characteristic of multiple catalytic metal, and catalytic performance is the most excellent
Good.
Accompanying drawing explanation
Fig. 1 is the EPMA analysis chart of the exhaust gas purifying catalyst in the first embodiment.
Detailed description of the invention
Hereinafter the preferred forms in the present invention is illustrated.
First embodiment:
Using as activated alumina (La doped gama-alumina) 100g of inorganic oxide, Ceria-zirconia composite oxygen
Compound (CeZrLaY, zirconium oxide/cerium oxide ratio is 65/35) 60g and Barium acetate (purity more than 99%) 7.0g joins acetic acid
In the mixed solution of 1.8g and pure water 0.17L, utilize alumina lap machine pulverize and mix, prepare carrier paste.Adding
In the case of adding zirconates, this carrier paste adds mixed nitrate oxygen zirconium (purity more than 99.0%) etc., then adds mixing
Palladous nitrate. (Tianzhonggui Metal Industrial Co., Ltd's system) 8.3g and rhodium nitrate (Tianzhonggui Metal Industrial Co., Ltd's system) 1.7g, system
Standby mixed slurry.The pH of this slurry is about 4.4.Add acetic acid in this slurry, water adjusts viscosity, and is coated on support
On body (cordierite integral material (モ ノ リ ス), volume 1L, hole count 600cpsi, wall thickness 4.3mil).Described above mixed
In stage after closing slurry preparation and till being applied on supporter, it is not added with aqueous slkali.After being dried 30 minutes at 95 DEG C,
Calcine 2 hours at 500 DEG C, obtain exhaust gas purifying catalyst (test No.1-2).
As described in Table 1, for being not added with the catalyst (test No.1-1) of barium salt and zirconates, changing adding of zirconates
The catalyst (test No.1-3～1-5) of dosage, use zirconium acetate, zirconium hydroxide, zirconia sol replace urging of zirconyl nitrate
Agent (test No.1-6～1-8), manufactures also by method similar to the above.It addition, also manufacture comprise zirconyl nitrate,
And use barium sulfate as barium salt to replace the catalyst (test No.1-9) of Barium acetate.
[table 1]
The addition of ※ Ba salt and Zr salt is the ratio after oxide conversion.
About the catalyst obtained in above-mentioned, the zirconium in analysis of catalyst layer/cerium concentration ratio, to catalytic metal on carrier
Load condition be also carried out confirm.It addition, as catalytic performance, have rated the exhaust gas purifying ability of CO, NO, HC.
For the catalyst of above-mentioned test No.1-3～1-5, use electron ray microscopic analyzer (EPMA) to analyze and urge
Zirconium in agent layer/cerium concentration ratio.About electronbeam irradiation condition, be set as accelerating potential 20kV, irradiate electric current 1.0 ×
10-8A, from supporter immediate vicinity to catalyst layer top layer every 0.2 μm mobile electron ray irradiation position to catalyst layer
Carry out ray analysis.Obtain the zirconium/cerium to the place that locates of the degree of depth supporting side 5～10 μm from catalyst layer top layer
Average (the X of concentration ratio1) and from supporter and the interface of catalyst layer locating to the degree of depth of side, top layer 5～10 μm
Average (the X of the zirconium/cerium concentration ratio at place2).In this test, it is less than 10 locate as catalysis using the X-ray intensity of Zr
The most surface of oxidant layer.Obtain obtained side, top layer zirconium/cerium ratio (X1) with support side zirconium/cerium ratio (X2) ratio, as urging
Side, agent layer top layer and the zirconium concentration ratio (X supporting side1/X2).By shown in Figure 1 for the EPMA measurement result about No.1-5.
[table 2]
The addition of ※ Zr salt is the ratio after oxide conversion.
From Fig. 1, table 2 it has been confirmed that the catalyst adding Zr salt and manufacturing, the Zr/Ce near catalyst layer top layer is high
In the near interface with supporter.
Then, confirm based on or without the load condition that add Ba salt and Zr salt, catalytic metal is to carrier.This validation test
In, in manufacturing the operation of each catalyst of test No.1-1,1-2,1-9, use the mixed slurry after adding catalytic metal salt.
Specifically, obtain for carrying out filter filtration after the mixed slurry centrifugation after adding Palladous nitrate. and rhodium nitrate
Supernatant, utilizes high-frequency induction coupled plasma method (ICP) to analyze the concentration of the noble metal (Pd and Rh) contained in liquid.By
Precious metal concentration in supernatant obtains the ratio being fixed on inorganic oxide carrier in the noble metal adding in slurry.
The above results is, the mixed slurry in the manufacturing process of the catalyst (test No.1-1) being not added with zirconates and barium salt
In, the palladium being fixed on carrier and the ratio of rhodium are 87%.On the other hand, with the addition of the catalyst (test No.1-2) of barium salt
In, fixing palladium and the ratio of rhodium are 70%.It addition, with the addition of the catalyst (test No.1-9) of both zirconates and barium salt
In, almost palladium and the rhodium of 100% is all fixed.
Then, for the catalyst of above test No.1-1～1-9, evaluate exhaust-gas purifying performance (T50).Performance evaluation
In, use the catalyst with cylindric stamping-out core from supporter.Catalyst after stamping-out core performance evaluation it
Before, use the degradation treatment that atmosphere furnace is carried out 10 hours at 900 DEG C.About the reacting gas of performance evaluation, start to simulate
Machine waste gas, uses CO210%, CO 0.77%, H20.2%, C3H8 100ppm、C3H6 300ppm、NO800ppm、O2
0.4%, H2O 10.0%, as rich gas, uses CO210%, CO 0.77%, H20.2%, C3H8 100ppm、C3H6
300ppm、NO 800ppm、O20.4%, H2O 10.0% is as lean gas.The surplus of arbitrary atmosphere gas is N2.To catalyst
The reacting gas of supply was with 90000 hours-1Space velocity (SV) switched rich gas/lean gas continuously every 1 second.Make catalyst
Inlet temperature in the temperature reaction rising high-temperature from 100 to 600 DEG C with 40 DEG C/min is tested, analysis of catalyst entrance and going out
The reacting gas composition of mouth, measures carbon monoxide, Hydrocarbon, the purifying rate of nitrogen oxides.Purifying rate is reached 50%
Temperature is as T50, evaluate detergent power.T50The lowest, represent that the detergent power of catalyst is the highest.
[table 3]
Addition weight % of ※ Ba salt and Zr salt is the ratio after oxide conversion
It will be apparent from the above that, the T of the catalyst (test No.1-3～1-9) containing zirconates50Low, arbitrary in CO, NO, HC
Purifying property aspect all demonstrates high catalysis activity.During it addition, contain both barium and zirconium oxide (test No.1-9), T50Special
The lowest, demonstrate good catalysis activity.
It will be apparent from the above that, with the addition of the catalyst of zirconates compared with the catalyst being not added with zirconates, be fixed on carrier
The amount of catalytic metal is more, and catalysis activity is better.With the addition of in the catalyst of both barium and zirconium oxide, the catalysis used
Metal is nearly all fixed, and catalysis activity is the highest.
Second embodiment:
The barium sulfate using the particle diameter shown in table 4 below manufactures catalyst.Other manufacturing conditions, performance evaluation by with
The same method of first embodiment is carried out.
[table 4]
Addition weight % of ※ Ba salt and Zr salt is the ratio after oxide conversion.
It will be apparent from the above that, the particle diameter at barium compound be 0.01 μm less than 2 μm time, T50The lowest, demonstrate good
Good catalysis activity.
3rd embodiment:
The dispersion of catalytic metal in catalyst layer is evaluated by CO absorption method.It addition, after to carrying out degradation treatment
Catalyst be also carried out evaluate.
The barium salt shown in table 5 below and zirconates is used to manufacture catalyst.In test No.3-1, add in carrier paste
After Palladous nitrate. and rhodium nitrate, add TEAH and make as aqueous slkali pH rise to 7.0.For testing the catalysis of No.3-3～3-5
Agent, after manufacturing catalyst, carries out the degradation treatment of 10 hours at 950 DEG C.Other catalyst manufacturing conditions are implemented with first
Mode similarly manufactures catalyst.
For the catalyst obtained in above, utilize CO Pulse adsorption method to measure the unit dispersion peace of catalytic metal
All particle diameters.Specifically, catalyst is kept 15 minutes at 400 DEG C in oxygen atmosphere, then also 400 in hydrogen atmosphere
DEG C keep 15 minutes, after being then cooled to 50 DEG C in helium atmosphere, by CO impulse method measure CO adsorbance.By this survey
Fixed, it is possible to measure the atomic number of the catalytic metal being exposed to catalyst layer surface.And, unit dispersion represents and is supported on carrier
On catalytic metal amount in be exposed to the ratio (%) of amount of catalyst layer surface, calculated by CO adsorbance.Unit is divided
Divergence is the biggest, then the surface area of the part exposing catalytic metal in catalyst layer surface is the biggest, is thus susceptible to obtain functional
Catalyst.It addition, from the surface area of the catalytic metal calculated according to CO adsorbance and the shape of catalytic metal is assumed to ball
Shape calculates mean diameter.
[table 5]
※ 1: carry out utilizing the pH of aqueous slkali (TEAH) to adjust.
Addition weight % of ※ 2:Ba salt and Zr salt is the ratio after oxide conversion.
※ 3: in test No.3-3, the gathering of catalyst metals is notable, and C0 adsorbance based on CO impulse method is few, therefore
Fail to detect.
Never, from the point of view of carrying out the catalyst (test No.3-1,3-2) of degradation treatment, add zirconates and do not use aqueous slkali
Catalyst (test No.3-2), adjusts compared with the catalyst after pH (test No.3-1), the list of catalytic metal with use aqueous slkali
Position dispersion is higher, and mean diameter is the least.Think that in the catalyst after adding aqueous slkali, catalytic metal is with the shape of hydroxide
Formula there occurs sedimentation, and therefore catalytic metal there occurs big particle diameter.
About the catalyst (test No.3-3～3-5) after carrying out 10 hours degradation treatment at 900 DEG C, it is being not added with zirconates
Catalyst (test No.3-3) in, it was observed that the large-scale aggregating of catalytic metal, it is impossible to carry out utilizing the dispersion of CO impulse method
Degree and the calculating of particle diameter.On the other hand, with the addition of the catalyst (test No.3-4,3-5) of zirconates, and do not carry out degradation treatment
Catalyst is compared, although observe the decline of dispersion and the increase of particle diameter, but compared with the catalyst being not added with zirconates, catalysis
The gathering of metal is suppressed.Therefore, for the catalyst that with the addition of zirconates, even if due to the use etc. of catalyst
And in the case of making catalyst deteriorate, it is also possible to expect the effect of the gathering of suppression catalytic metal.
Industrial applicability
In accordance with the invention it is possible to provide the catalysis that the catalytic performance as exhaust gas purifying catalyst is high, manufacturing cost is the lowest
Agent.The exhaust gas purifying catalyst of the present invention is particularly suitable as three-way catalyst.
Claims (13)
1. an exhaust gas purifying catalyst, it is the waste gas purification catalysis forming single catalyst layer on supporter
Agent, wherein,
Described catalyst layer be by least any one inorganic oxide constituted in aluminium oxide, cerium oxide, zirconium oxide with
The supported on carriers that Ceria-zirconia composite oxides mix has the catalyst layer of palladium and rhodium,
Further, the zirconium concentration (S on the surface of described catalyst layerZr) and cerium concentration (SCe) ratio (SZr/SCe) relative to catalyst layer
The zirconium concentration (C at the interface with supporterZr) and cerium concentration (CCe) ratio (CZr/CCe) it is 1.05～6.0.
2. exhaust gas purifying catalyst as claimed in claim 1, wherein, catalyst layer is possibly together with barium compound.
3. exhaust gas purifying catalyst as claimed in claim 2, wherein, barium compound includes in barium sulfate, brium carbonate, Barium monoxide
Any one.
4. as claimed in claim 2 or claim 3 exhaust gas purifying catalyst, wherein, the particle diameter of barium compound is more than 0.01 μm and little
In 2.0 μm.
5. a manufacture method for exhaust gas purifying catalyst, its waste gas purification catalysis according to any one of Claims 1 to 4
The manufacture method of agent, described manufacture method includes:
The carrier paste of inorganic oxide and Ceria-zirconia composite oxides suspendible will add palladium salt and rhodium salt
And prepare as catalyst layer precursor mixed slurry operation and
Described mixed slurry is coated the operation forming single-layer catalyst precursor layer on supporter,
Carrier paste in the interpolation palladium salt of the described operation preparing mixed slurry and the stage of rhodium salt is contained within zirconium compounds.
6. manufacture method as claimed in claim 5, wherein, on the interpolation palladium salt of operation and the rank of rhodium salt of preparing mixed slurry
Possibly together with insoluble barium compound in the carrier paste of section.
7. manufacture method as claimed in claim 6, wherein, insoluble barium compound is barium sulfate or brium carbonate.
Manufacture method the most as claimed in claims 6 or 7, wherein, is converted into oxygen relative to by the whole compositions in catalyst layer
The quality of compound, the addition of insoluble barium compound is calculated as 1.0～10 mass % to be converted into barytic quality.
9. the manufacture method as according to any one of claim 5～8, wherein, zirconium compounds is zirconyl nitrate, zirconium acetate, oxygen
More than any one in change zirconium colloidal sol.
10. the manufacture method as according to any one of claim 5～9, wherein, relative to by the whole compositions in catalyst layer
Being converted into the quality of oxide, the addition of zirconium compounds is calculated as 0.5～5.0 mass % to be converted into zirconic quality.
11. the manufacture method as according to any one of claim 6～10, wherein, by insoluble barium compound and cerium oxide-oxygen
Change and carry out after zirconium mixed oxide and inorganic oxide are mixed together slurried preparing carrier paste.
12. manufacture methods as according to any one of claim 5～11, wherein, by Ceria-zirconia composite oxides
Mix with inorganic oxide and carry out slurried and after preparing carrier paste, before the interpolation of palladium salt and rhodium salt, carry out zirconium compounds
Interpolation.
13. manufacture methods as according to any one of claim 5～12, wherein, after the formation process of catalyst precarsor layer,
At 400～700 DEG C, supporter is calcined and form catalyst layer.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013249137A JP5777690B2 (en) | 2013-12-02 | 2013-12-02 | Exhaust gas purification catalyst and method for producing the same |
| JP2013-249137 | 2013-12-02 | ||
| PCT/JP2014/081205 WO2015083590A1 (en) | 2013-12-02 | 2014-11-26 | Exhaust-gas purifying catalyst and method for producing same |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108993560A (en) * | 2018-07-25 | 2018-12-14 | 昆明贵研催化剂有限责任公司 | A kind of water resistant, high temperature resistant methane oxidation catalyst and preparation method thereof |
| CN111405941A (en) * | 2017-12-28 | 2020-07-10 | 优美科触媒日本有限公司 | Catalyst for hydrogen production and catalyst for exhaust gas purification using same |
| CN112675845A (en) * | 2020-12-28 | 2021-04-20 | 四川大学 | Pd-Rh single-coating catalyst for purifying tail gas of natural gas vehicle and preparation method thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN108602049B (en) * | 2016-01-28 | 2021-09-03 | 株式会社科特拉 | Pd-supporting Zr-based composite oxide |
| EP3581269B1 (en) | 2017-04-11 | 2022-09-28 | Cataler Corporation | Catalyst for exhaust gas purification and method of preparation |
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| CN108993560A (en) * | 2018-07-25 | 2018-12-14 | 昆明贵研催化剂有限责任公司 | A kind of water resistant, high temperature resistant methane oxidation catalyst and preparation method thereof |
| CN112675845A (en) * | 2020-12-28 | 2021-04-20 | 四川大学 | Pd-Rh single-coating catalyst for purifying tail gas of natural gas vehicle and preparation method thereof |
Also Published As
| Publication number | Publication date |
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| WO2015083590A1 (en) | 2015-06-11 |
| CN105792929B (en) | 2018-06-26 |
| JP2015104715A (en) | 2015-06-08 |
| JP5777690B2 (en) | 2015-09-09 |
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