JP6909402B2 - A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. - Google Patents
A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. Download PDFInfo
- Publication number
- JP6909402B2 JP6909402B2 JP2017136455A JP2017136455A JP6909402B2 JP 6909402 B2 JP6909402 B2 JP 6909402B2 JP 2017136455 A JP2017136455 A JP 2017136455A JP 2017136455 A JP2017136455 A JP 2017136455A JP 6909402 B2 JP6909402 B2 JP 6909402B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- gas purification
- catalyst carrier
- oxide
- alumina
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000003054 catalyst Substances 0.000 title claims description 132
- 238000000746 purification Methods 0.000 title claims description 79
- 238000004519 manufacturing process Methods 0.000 title claims description 16
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 112
- 239000011148 porous material Substances 0.000 claims description 50
- 229910000510 noble metal Inorganic materials 0.000 claims description 28
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 21
- 239000011164 primary particle Substances 0.000 claims description 20
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims description 16
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims description 16
- 239000002131 composite material Substances 0.000 claims description 16
- 239000007787 solid Substances 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 7
- -1 amine compound Chemical class 0.000 claims description 6
- 238000010304 firing Methods 0.000 claims description 6
- 239000002243 precursor Substances 0.000 claims description 6
- 239000007789 gas Substances 0.000 description 100
- 239000000843 powder Substances 0.000 description 47
- 239000002245 particle Substances 0.000 description 37
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 32
- 239000001301 oxygen Substances 0.000 description 32
- 229910052760 oxygen Inorganic materials 0.000 description 32
- 238000010521 absorption reaction Methods 0.000 description 25
- 230000007423 decrease Effects 0.000 description 18
- 239000002121 nanofiber Substances 0.000 description 18
- 230000003197 catalytic effect Effects 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 15
- 239000007864 aqueous solution Substances 0.000 description 14
- 239000000463 material Substances 0.000 description 14
- 239000000126 substance Substances 0.000 description 13
- 239000002923 metal particle Substances 0.000 description 12
- 238000002156 mixing Methods 0.000 description 10
- 239000002994 raw material Substances 0.000 description 10
- 239000003795 chemical substances by application Substances 0.000 description 9
- 230000003472 neutralizing effect Effects 0.000 description 9
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 238000005245 sintering Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 6
- 230000004888 barrier function Effects 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 6
- 238000009792 diffusion process Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 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 6
- 238000000034 method Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 239000008188 pellet Substances 0.000 description 6
- 239000011882 ultra-fine particle Substances 0.000 description 6
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 5
- 238000009826 distribution Methods 0.000 description 5
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 5
- 229910052753 mercury Inorganic materials 0.000 description 5
- 229910044991 metal oxide Inorganic materials 0.000 description 5
- 150000004706 metal oxides Chemical class 0.000 description 5
- 239000010970 precious metal Substances 0.000 description 5
- 229910002651 NO3 Inorganic materials 0.000 description 4
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 4
- 238000003917 TEM image Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 3
- 238000013019 agitation Methods 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 239000000969 carrier Substances 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229940093429 polyethylene glycol 6000 Drugs 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 2
- SLXKOJJOQWFEFD-UHFFFAOYSA-N 6-aminohexanoic acid Chemical compound NCCCCCC(O)=O SLXKOJJOQWFEFD-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 229920002873 Polyethylenimine Polymers 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- HKVFISRIUUGTIB-UHFFFAOYSA-O azanium;cerium;nitrate Chemical compound [NH4+].[Ce].[O-][N+]([O-])=O HKVFISRIUUGTIB-UHFFFAOYSA-O 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 238000005119 centrifugation Methods 0.000 description 2
- 238000010908 decantation Methods 0.000 description 2
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 239000000835 fiber Substances 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 229910000480 nickel oxide Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 2
- 238000007873 sieving Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- NGDQQLAVJWUYSF-UHFFFAOYSA-N 4-methyl-2-phenyl-1,3-thiazole-5-sulfonyl chloride Chemical compound S1C(S(Cl)(=O)=O)=C(C)N=C1C1=CC=CC=C1 NGDQQLAVJWUYSF-UHFFFAOYSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 229910000505 Al2TiO5 Inorganic materials 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000002776 aggregation Effects 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
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Chemical compound [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000010586 diagram Methods 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
- 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
- 238000001704 evaporation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000002706 hydrostatic effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229910021432 inorganic complex Inorganic materials 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- PLDDOISOJJCEMH-UHFFFAOYSA-N neodymium(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Nd+3].[Nd+3] PLDDOISOJJCEMH-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- AABBHSMFGKYLKE-SNAWJCMRSA-N propan-2-yl (e)-but-2-enoate Chemical compound C\C=C\C(=O)OC(C)C AABBHSMFGKYLKE-SNAWJCMRSA-N 0.000 description 1
- 229910052707 ruthenium Inorganic materials 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
- 238000001179 sorption measurement Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 1
Images
Description
本発明は、排ガス浄化用触媒担体、それを用いた排ガス浄化用触媒、及び排ガス浄化用触媒担体の製造方法に関する。 The present invention relates to an exhaust gas purification catalyst carrier, an exhaust gas purification catalyst using the same, and a method for producing an exhaust gas purification catalyst carrier.
従来から、様々な金属酸化物を含有する複合酸化物が排ガス浄化用触媒担体等として利用されてきた。このような複合酸化物中の金属酸化物としては、雰囲気中の酸素分圧に応じて酸素の吸放出が可能である（酸素吸蔵放出能を持つ）ことから、セリアが好適に用いられてきた。しかしながら、セリアは耐熱性が低く、セリアを含む担体に貴金属粒子を担持した排ガス浄化用触媒は、高温に曝されると、貴金属粒子が粒成長するため、触媒活性が低下するという問題があった。 Conventionally, composite oxides containing various metal oxides have been used as catalyst carriers for exhaust gas purification. As the metal oxide in such a composite oxide, ceria has been preferably used because it can absorb and release oxygen according to the partial pressure of oxygen in the atmosphere (has an oxygen occlusion and release ability). .. However, ceria has low heat resistance, and the exhaust gas purification catalyst in which the noble metal particles are supported on a carrier containing ceria has a problem that the catalytic activity is lowered because the noble metal particles grow when exposed to a high temperature. ..
そこで、このような貴金属粒子の粒成長を抑制した排ガス浄化用触媒として、例えば、特開２００７−２２９６５３号公報（特許文献１）には、貴金属粒子と、この貴金属粒子を担持するセリア等の化合物担体と、この貴金属粒子を担持した前記化合物担体を内包し、この内包された前記化合物担体同士を離隔する、平均アスペクト比等の物理的性状の異なる２種以上のアルミナ等の包接材とを有する排ガス浄化用触媒が開示されている。この排ガス浄化用触媒においては、貴金属粒子を担持した前記化合物担体が物理的性状の異なる２種以上の包接材により内包され、かつ、前記化合物担体同士が前記包接材により離隔された構造を有しているため、貴金属粒子の凝集が抑制され、長期間にわたり貴金属粒子の活性向上効果が維持される。しかしながら、貴金属粒子を担持した前記化合物担体が物理的性状の異なる２種以上の包接材により内包された構造では、細孔容量が非常に小さく、また、細孔構造を制御できないため、ガスの拡散性が低く、高い酸素吸放出速度が得られないという問題があった。 Therefore, as a catalyst for purifying exhaust gas that suppresses the grain growth of such noble metal particles, for example, Japanese Patent Application Laid-Open No. 2007-229653 (Patent Document 1) describes the noble metal particles and compounds such as ceria supporting the noble metal particles. A carrier and an encapsulating material such as two or more kinds of alumina having different physical properties such as an average aspect ratio, which encloses the compound carrier carrying the noble metal particles and separates the contained compound carriers from each other. The catalyst for purifying exhaust gas is disclosed. In this exhaust gas purification catalyst, the compound carrier supporting the noble metal particles is encapsulated by two or more kinds of inclusion materials having different physical properties, and the compound carriers are separated from each other by the inclusion material. Since it has, the aggregation of the noble metal particles is suppressed, and the effect of improving the activity of the noble metal particles is maintained for a long period of time. However, in the structure in which the compound carrier carrying the noble metal particles is encapsulated by two or more kinds of packaging materials having different physical properties, the pore volume is very small and the pore structure cannot be controlled. There is a problem that the diffusibility is low and a high oxygen absorption / release rate cannot be obtained.
本発明は、上記従来技術の有する課題に鑑みてなされたものであり、高温に曝された場合であっても優れた酸素吸放出速度（ＯＳＣ速度）を示す排ガス浄化用触媒、このような触媒を形成することが可能な排ガス浄化用触媒担体及びその製造方法を提供することを目的とする。 The present invention has been made in view of the above-mentioned problems of the prior art, and is an exhaust gas purification catalyst that exhibits an excellent oxygen absorption / release rate (OSC rate) even when exposed to a high temperature, such a catalyst. It is an object of the present invention to provide a catalyst carrier for exhaust gas purification capable of forming the above and a method for producing the same.
本発明者らは、上記目的を達成すべく鋭意研究を重ねた結果、粒子状酸化物及びその前駆体のうちの少なくとも一方を含有するナノコロイドと、平均アスペクト比が大きい繊維状アルミナ系酸化物とを含有するナノコロイドゾルを用いることによって、メソ細孔の細孔容量が大きい焼成粉末が得られることを見出し、さらに、この焼成粉末が、高温に曝された場合であっても優れた酸素吸放出速度（ＯＳＣ速度）を示す排ガス浄化用触媒の担体として有用であることを見出し、本発明を完成するに至った。 As a result of intensive studies to achieve the above object, the present inventors have made nanocolloids containing at least one of a particulate oxide and a precursor thereof, and a fibrous alumina-based oxide having a large average aspect ratio. By using a nanocolloidal sol containing and, it was found that a calcined powder having a large pore capacity of mesopores can be obtained, and further, the calcined powder is excellent in oxygen even when exposed to a high temperature. We have found that it is useful as a carrier for a catalyst for purifying exhaust gas, which exhibits an absorption / release rate (OSC rate), and have completed the present invention.
すなわち、本発明の排ガス浄化用触媒担体は、平均短径が１〜２０ｎｍかつ平均アスペクト比が１０以上である繊維状アルミナ系酸化物と、平均一次粒子径が１〜２０ｎｍかつ平均アスペクト比が３以下であり、セリアを含有する粒子状酸化物と、を含有し、細孔直径が３〜５０ｎｍのメソ細孔を有し、該メソ細孔の触媒担体１ｇ当たりの全細孔容量が０．３ｃｍ ３ ／ｇ以上であることを特徴とするものである。 That is, the catalyst carrier for exhaust gas purification of the present invention contains a fibrous alumina-based oxide having an average minor axis of 1 to 20 nm and an average aspect ratio of 10 or more, and an average primary particle size of 1 to 20 nm and an average aspect ratio of 3. It is described below, contains a particulate oxide containing ceria, has mesopores having a pore diameter of 3 to 50 nm, and the total pore volume per 1 g of the catalyst carrier of the mesopores is 0. It is characterized in that it is 3 cm 3 / g or more.
さらに、本発明の排ガス浄化用触媒担体においては、前記粒子状酸化物が前記繊維状アルミナ系酸化物上に担持されていることが好ましく、また、前記繊維状アルミナ系酸化物が網目状構造を形成していることが好ましく、さらに、前記粒子状酸化物が、セリアを含有する複合酸化物であることが好ましく、セリアとジルコニアとを含有する複合酸化物であることがより好ましい。 Further, in the catalyst carrier for exhaust gas purification of the present invention, it is preferable that the particulate oxide is supported on the fibrous alumina-based oxide, and the fibrous alumina-based oxide has a network structure. it is preferable that the forming, further, the particulate oxide is preferably a composite oxide containing ceria, and more preferably a composite oxide containing ceria and zirconia.
本発明の排ガス浄化用触媒は、このような本発明の排ガス浄化用触媒担体と、この触媒担体に担持されている貴金属とを含有するものである。 The exhaust gas purification catalyst of the present invention contains such an exhaust gas purification catalyst carrier of the present invention and a noble metal supported on the catalyst carrier.
本発明の排ガス浄化用触媒担体の製造方法は、セリアを含有する粒子状酸化物及びその前駆体のうちの少なくとも一方を含有するナノコロイドと、平均短径が１〜２０ｎｍかつ平均アスペクト比が１０以上である繊維状アルミナ系酸化物とを混合してナノコロイドゾルを調製し、該ナノコロイドゾルにアミン化合物を添加した後、生成した固体成分に乾燥処理及び焼成処理を施して触媒担体を得ることを特徴とする。 The method for producing a catalyst carrier for purifying exhaust gas of the present invention comprises a nanocolloid containing at least one of a particulate oxide containing ceria and a precursor thereof, and an average minor axis of 1 to 20 nm and an average aspect ratio of 10. A nanocolloidal sol is prepared by mixing with the above-mentioned fibrous alumina-based oxide, an amine compound is added to the nanocolloidal sol, and then the produced solid component is subjected to a drying treatment and a baking treatment to obtain a catalyst carrier. It is characterized by that.
なお、本発明の排ガス浄化用触媒が、高温に曝された場合であっても優れた酸素吸放出速度（ＯＳＣ速度）を示す理由は必ずしも定かではないが、本発明者らは以下のように推察する。すなわち、本発明の排ガス浄化用触媒担体は、平均アスペクト比が大きな繊維状アルミナ系酸化物と粒子状酸化物とを含有するものであり、このような触媒担体においては、図１に示すように、繊維状アルミナ系酸化物１が互いに絡み合った構造（好ましくは、網目状構造）を形成しており、この絡み合った繊維状アルミナ系酸化物１の表面に粒子状酸化物２が配置（好ましくは、担持）された構造を形成している。また、本発明の排ガス浄化用触媒は、このような触媒担体に貴金属が担持されたものである。本発明の排ガス浄化用触媒においては、繊維状アルミナ系酸化物の表面に粒子状酸化物が配置されており、この繊維状アルミナ系酸化物の表面に粒子状酸化物が配置された触媒担体に貴金属が担持されているため、アルミナの拡散障壁機能により、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が抑制され、触媒活性の低下が抑制されると推察される。また、本発明の排ガス浄化用触媒においては、絡み合った繊維状アルミナ系酸化物によって容量の大きな細孔（特に、メソ細孔）が形成されるため、ガスの拡散性が高くなり、優れた酸素吸放出速度（ＯＳＣ速度）が得られると推察される。そして、繊維状アルミナ系酸化物が互いに絡み合った構造は、アルミナの空間保持機能により、高温下においても、その形状が保持され、大きな細孔容量（特に、メソ細孔の細孔容量）は維持されるため、高いガス拡散性が得られるとともに、粒子状酸化物や貴金属のシンタリングによる粒成長が抑制されて触媒活性の低下が抑制されると推察される。このように、本発明の優れた排ガス浄化用触媒は、高温に曝された場合であっても、粒子状酸化物や貴金属のシンタリングによる粒成長が抑制されて触媒活性の低下が抑制され、さらに、大きな細孔容量（特に、メソ細孔の細孔容量）が維持されて高いガス拡散性が得られるため、優れた酸素吸放出速度（ＯＳＣ速度）及び触媒活性を示すと推察される。
The reason why the exhaust gas purification catalyst of the present invention exhibits an excellent oxygen absorption / release rate (OSC rate) even when exposed to a high temperature is not always clear, but the present inventors have described as follows. Guess. That is, the catalyst carrier for exhaust gas purification of the present invention contains a fibrous alumina-based oxide and a particulate oxide having a large average aspect ratio, and such a catalyst carrier is as shown in FIG. , The fibrous alumina-based
一方、アルミナ粒子と他の粒子状酸化物（例えば、セリア−ジルコニア系複合酸化物粒子）とを含有する従来の排ガス浄化用触媒担体においては、図２及び図３に示すように、扁球状又は針状のアルミナ粒子３と他の粒子状酸化物４とが凝集した構造を形成している。このようなアルミナ粒子と他の粒子状酸化物とが凝集した構造においては、容量の大きな細孔（特に、メソ細孔）が形成されにくく、本発明の排ガス浄化用触媒担体に比べて、細孔容量（特に、メソ細孔の細孔容量）が小さくなるため、ガスの拡散性が低下し、さらに、高温に曝された場合に、粒子状酸化物や貴金属のシンタリングによる粒成長が十分に抑制されないため、触媒活性が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなると推察される。
On the other hand, in the conventional catalyst carrier for exhaust gas purification containing alumina particles and other particulate oxides (for example, ceria-zirconia-based composite oxide particles), as shown in FIGS. The needle-
本発明によれば、高温に曝された場合であっても優れた酸素吸放出速度（ＯＳＣ速度）を示す排ガス浄化用触媒、並びに、このような触媒を形成することが可能な排ガス浄化用触媒担体を得ることが可能となる。 According to the present invention, an exhaust gas purification catalyst exhibiting an excellent oxygen absorption / release rate (OSC rate) even when exposed to a high temperature, and an exhaust gas purification catalyst capable of forming such a catalyst. It becomes possible to obtain a carrier.
以下、本発明をその好適な実施形態に即して詳細に説明する。 Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof.
〔排ガス浄化用触媒担体〕
先ず、本発明の排ガス浄化用触媒担体について説明する。本発明の排ガス浄化用触媒担体は、平均短径が１〜２０ｎｍかつ平均アスペクト比が１０以上である繊維状アルミナ系酸化物と、平均一次粒子径が１〜２０ｎｍかつ平均アスペクト比が３以下である粒子状酸化物と、を含有するものである。
[Catalyst carrier for exhaust gas purification]
First, the exhaust gas purification catalyst carrier of the present invention will be described. The catalyst carrier for exhaust gas purification of the present invention has a fibrous alumina-based oxide having an average minor axis of 1 to 20 nm and an average aspect ratio of 10 or more, and an average primary particle size of 1 to 20 nm and an average aspect ratio of 3 or less. It contains a certain particulate oxide.
本発明の排ガス浄化用触媒担体において、繊維状アルミナ系酸化物の平均短径は１〜２０ｎｍである。繊維状アルミナ系酸化物の平均短径が前記下限未満になると、繊維状アルミナ系酸化物の熱安定性が低下し、粒子状酸化物及び繊維状アルミナ系酸化物のシンタリングを誘発しやすくなり、繊維状アルミナ系酸化物の絡み合った構造が維持できなくなるおそれがあり、他方、前記上限を超えると、粒子状酸化物とナノレベルで均一に混合された状態を形成することが困難となる。また、拡散障壁としての機能が十分に発現し、粒子状酸化物のシンタリングが抑制されるという観点から、繊維状アルミナ系酸化物の平均短径としては、３〜１０ｎｍが好ましく、３〜８ｎｍがより好ましい。 In the exhaust gas purification catalyst carrier of the present invention, the average minor axis of the fibrous alumina-based oxide is 1 to 20 nm. When the average minor axis of the fibrous alumina-based oxide is less than the above lower limit, the thermal stability of the fibrous alumina-based oxide is lowered, and syntaring of the particulate oxide and the fibrous alumina-based oxide is likely to be induced. On the other hand, if the above upper limit is exceeded, it becomes difficult to form a state in which the fibrous alumina-based oxide is uniformly mixed with the particulate oxide at the nano level. Further, from the viewpoint that the function as a diffusion barrier is sufficiently exhibited and the sintering of particulate oxide is suppressed, the average minor axis of the fibrous alumina-based oxide is preferably 3 to 10 nm, preferably 3 to 8 nm. Is more preferable.
また、本発明の排ガス浄化用触媒担体において、繊維状アルミナ系酸化物の平均アスペクト比は１０以上である。繊維状アルミナ系酸化物の平均アスペクト比が前記下限未満になると、繊維状アルミナ系酸化物が互いに絡み合った構造が形成されず、容量の大きな細孔（特に、メソ細孔）が形成されないため、ガスの拡散性が低下し、高い酸素吸放出速度（ＯＳＣ速度）が得られない。また、繊維状アルミナ系酸化物が互いに絡み合った構造が形成され、容量の大きな細孔（特に、メソ細孔）が形成されるため、ガス拡散性が高くなり、酸素吸放出速度（ＯＳＣ速度）が向上するという観点から、繊維状アルミナ系酸化物の平均アスペクト比としては、２０以上が好ましく、２５以上がより好ましく、５０以上が更に好ましい。なお、繊維状アルミナ系酸化物の平均アスペクト比の上限としては特に制限はないが、排ガス浄化用触媒として用いる粒子の大きさが数百ｎｍ〜数十μｍであることから、１０００以下が好ましく、７５０以下がより好ましい。 Further, in the catalyst carrier for exhaust gas purification of the present invention, the average aspect ratio of the fibrous alumina-based oxide is 10 or more. When the average aspect ratio of the fibrous alumina-based oxide is less than the above lower limit, a structure in which the fibrous alumina-based oxides are entangled with each other is not formed, and pores having a large capacity (particularly, mesopores) are not formed. The diffusivity of the gas is reduced, and a high oxygen absorption / release rate (OSC rate) cannot be obtained. In addition, a structure in which fibrous alumina-based oxides are entangled with each other is formed, and pores having a large capacity (particularly, mesopores) are formed, so that gas diffusivity is increased and the oxygen absorption / release rate (OSC rate) is increased. The average aspect ratio of the fibrous alumina-based oxide is preferably 20 or more, more preferably 25 or more, still more preferably 50 or more, from the viewpoint of improving the above. The upper limit of the average aspect ratio of the fibrous alumina-based oxide is not particularly limited, but is preferably 1000 or less because the size of the particles used as the catalyst for purifying the exhaust gas is several hundred nm to several tens of μm. More preferably, it is 750 or less.
なお、本発明において、繊維状アルミナ系酸化物の平均短径及び平均アスペクト比は以下の方法により求められる。すなわち、排ガス浄化用触媒担体を透過型電子顕微鏡（ＴＥＭ）により観察し、得られるＴＥＭ写真において、無作為に１０個の繊維状アルミナ系酸化物を抽出し、各繊維状アルミナ系酸化物の長軸方向の長さ（長径）及び長軸方向に垂直な方向の長さ（短径）を測定し、抽出した１０個の繊維状アルミナ系酸化物についての平均長径及び平均短径を求め、さらに、平均アスペクト比（＝平均長径／平均短径）を算出する。 In the present invention, the average minor axis and the average aspect ratio of the fibrous alumina-based oxide are obtained by the following methods. That is, the catalyst carrier for exhaust gas purification was observed with a transmission electron microscope (TEM), and 10 fibrous alumina-based oxides were randomly extracted from the obtained TEM photograph, and the length of each fibrous alumina-based oxide was obtained. The length in the axial direction (major axis) and the length in the direction perpendicular to the major axis direction (minor axis) are measured, and the average major axis and the average minor axis of the extracted 10 fibrous alumina-based oxides are obtained, and further. , Calculate the average aspect ratio (= average major axis / average minor axis).
このような繊維状アルミナ系酸化物としては、アルミナのみからなるものであってもよいし、アルミナと他の金属酸化物との複合酸化物であってもよい。前記他の金属酸化物としては、ランタナ（Ｌａ２Ｏ３）、酸化バリウム（ＢａＯ）、酸化マグネシウム（ＭｇＯ）、酸化カルシウム（ＣａＯ）、イットリア（Ｙ２Ｏ３）が挙げられる。前記複合酸化物においては、これらの他の金属酸化物のうちの１種とアルミナとが複合酸化物を形成していてもよいし、２種以上とアルミナとが複合酸化物を形成していてもよい。 Such a fibrous alumina-based oxide may be composed of only alumina, or may be a composite oxide of alumina and another metal oxide. Examples of the other metal oxide include lanthana (La 2 O 3 ), barium oxide (BaO), magnesium oxide (MgO), calcium oxide (CaO), and itria (Y 2 O 3 ). In the composite oxide, one of these other metal oxides and alumina may form a composite oxide, or two or more of them and alumina form a composite oxide. May be good.
本発明の排ガス浄化用触媒担体において、このような繊維状アルミナ系酸化物は互いに絡み合った構造を形成していることが好ましく、網目状構造を形成していることがより好ましい。繊維状アルミナ系酸化物がこのような構造を形成することによって、容量の大きな細孔（特に、メソ細孔）が形成されるため、ガスの拡散性が高くなり、酸素吸放出速度（ＯＳＣ速度）が向上する傾向にある。 In the exhaust gas purification catalyst carrier of the present invention, such fibrous alumina-based oxides preferably form a structure in which they are intertwined with each other, and more preferably a network structure. When the fibrous alumina-based oxide forms such a structure, pores having a large capacity (particularly, mesopores) are formed, so that the diffusivity of the gas becomes high and the oxygen absorption / release rate (OSC rate). ) Tends to improve.
また、本発明の排ガス浄化用触媒担体において、粒子状酸化物の平均一次粒子径は１〜２０ｎｍである。粒子状酸化物の平均一次粒子径が前記下限未満になる、又は、前記上限を超えると、繊維状アルミナ系酸化物とナノレベルで均一に混合された状態を形成することが困難となる。また、酸素吸放出活性や触媒活性のシンタリングによる低下が抑制されるという観点から、粒子状酸化物の平均一次粒子径としては、３〜２０ｎｍが好ましく、５〜１８ｎｍがより好ましい。 Further, in the catalyst carrier for exhaust gas purification of the present invention, the average primary particle size of the particulate oxide is 1 to 20 nm. If the average primary particle size of the particulate oxide is less than the lower limit or exceeds the upper limit, it becomes difficult to form a state in which the fibrous alumina-based oxide and the fibrous alumina-based oxide are uniformly mixed at the nano level. Further, from the viewpoint of suppressing the decrease in oxygen absorption / release activity and catalytic activity due to sintering, the average primary particle size of the particulate oxide is preferably 3 to 20 nm, more preferably 5 to 18 nm.
さらに、本発明の排ガス浄化用触媒担体において、粒子状酸化物の平均アスペクト比は３以下である。粒子状酸化物の平均アスペクト比が前記上限を超えると、粒子状酸化物の粒子径が粗大となり、触媒活性が低下する。また、特定の結晶面の異常成長やシンタリングを防止するという観点から、粒子状酸化物の平均アスペクト比としては、２．５以下が好ましく、１．５以下がより好ましい。なお、粒子状酸化物の平均アスペクト比の下限は通常１以上である。また、このような粒子状酸化物の形状としては平均アスペクト比が前記範囲を満たすものであれば特に制限はなく、例えば、真球状、扁球状、長球状等が挙げられる。 Further, in the catalyst carrier for exhaust gas purification of the present invention, the average aspect ratio of the particulate oxide is 3 or less. When the average aspect ratio of the particulate oxide exceeds the upper limit, the particle size of the particulate oxide becomes coarse and the catalytic activity decreases. Further, from the viewpoint of preventing abnormal growth and sintering of a specific crystal plane, the average aspect ratio of the particulate oxide is preferably 2.5 or less, more preferably 1.5 or less. The lower limit of the average aspect ratio of the particulate oxide is usually 1 or more. The shape of such a particulate oxide is not particularly limited as long as the average aspect ratio satisfies the above range, and examples thereof include true spheres, oblate spheres, and long spheres.
なお、本発明において、粒子状酸化物の平均一次粒子径及び平均アスペクト比は以下の方法により求められる。すなわち、排ガス浄化用触媒担体を透過型電子顕微鏡（ＴＥＭ）により観察し、得られるＴＥＭ写真において、無作為に１０個の粒子状酸化物（一次粒子）を抽出し、各粒子状酸化物（一次粒子）の長軸方向の長さ（長径）及び長軸方向に垂直な方向の長さ（短径）を測定し、長径と短径との算術平均値をその一次粒子の粒子径とし、抽出した１０個の粒子状酸化物（一次粒子）の平均粒子径（平均一次粒子径）を求める。また、抽出した１０個の粒子状酸化物（一次粒子）についての平均長径及び平均短径を求め、平均アスペクト比（＝平均長径／平均短径）を算出する。 In the present invention, the average primary particle size and the average aspect ratio of the particulate oxide are obtained by the following methods. That is, the catalyst carrier for exhaust gas purification is observed with a transmission electron microscope (TEM), and 10 particulate oxides (primary particles) are randomly extracted from the obtained TEM photograph, and each particulate oxide (primary) is extracted. Measure the length (major axis) in the major axis direction and the length (minor axis) in the direction perpendicular to the major axis direction, and use the arithmetic average value of the major axis and minor axis as the particle diameter of the primary particle to extract. The average particle size (average primary particle size) of the 10 particulate oxides (primary particles) is obtained. Further, the average major axis and the average minor axis of the 10 extracted particulate oxides (primary particles) are obtained, and the average aspect ratio (= average major axis / average minor axis) is calculated.
このような粒子状酸化物としては、セリア（ＣｅＯ２）、ジルコニア（ＺｒＯ２）、ランタナ（Ｌａ２Ｏ３）、イットリア（Ｙ２Ｏ３）、酸化プラセオジム（Ｐｒ２Ｏ３）、アルミナ（Ａｌ２Ｏ３）、酸化ネオジム（Ｎｄ２Ｏ３）、チタニア（ＴｉＯ２）、酸化鉄（III）（Ｆｅ２Ｏ３）、酸化ニッケル（ＮｉＯ）、及び酸化銅（II）（ＣｕＯ）からなる群から選択される少なくとも１種の酸化物が好ましい。前記粒子状酸化物がこれらの酸化物の２種以上からなるものである場合、それらは混合物（混合酸化物）であっても、複合物（複合酸化物）であってもよい。また、このような酸化物のうち、酸素吸放出性能及び排ガス浄化活性に優れているという観点から、セリア（ＣｅＯ２）を含有する複合酸化物がより好ましく、セリア（ＣｅＯ２）とジルコニア（ＺｒＯ２）とを含有する複合酸化物が更に好ましく、セリア（ＣｅＯ２）とジルコニア（ＺｒＯ２）とランタナ（Ｌａ２Ｏ３）とイットリア（Ｙ２Ｏ３）との複合酸化物が特に好ましい。 Examples of such particulate oxides include ceria (CeO 2 ), zirconia (ZrO 2 ), lanthana (La 2 O 3 ), itria (Y 2 O 3 ), placeodym oxide (Pr 2 O 3 ), and alumina (Al). A group consisting of 2 O 3 ), neodymium oxide (Nd 2 O 3 ), titania (TiO 2 ), iron (III) oxide (Fe 2 O 3 ), nickel oxide (NiO), and copper (II) oxide (CuO). At least one oxide selected from the above is preferred. When the particulate oxide is composed of two or more of these oxides, they may be a mixture (mixed oxide) or a composite (composite oxide). Further, among such oxides, a composite oxide containing ceria (CeO 2 ) is more preferable from the viewpoint of excellent oxygen absorption / release performance and exhaust gas purification activity, and ceria (CeO 2 ) and zirconia (ZrO) are more preferable. A composite oxide containing 2 ) is more preferable, and a composite oxide of ceria (CeO 2 ), zirconia (ZrO 2 ), lanthana (La 2 O 3 ), and itria (Y 2 O 3 ) is particularly preferable.
本発明の排ガス浄化用触媒担体は、このような繊維状アルミナ系酸化物と粒子状酸化物とを含有するものである。本発明の排ガス浄化用触媒担体において、前記粒子状酸化物は、前記繊維状アルミナ系酸化物上（より好ましくは、表面上）に配置（より好ましくは、担持）されていることが好ましく、前記繊維状アルミナ系酸化物により形成された網目状構造中に一次粒子レベルで均一に担持されていることが特に好ましい。 The catalyst carrier for exhaust gas purification of the present invention contains such a fibrous alumina-based oxide and a particulate oxide. In the catalyst carrier for exhaust gas purification of the present invention, the particulate oxide is preferably arranged (more preferably supported) on the fibrous alumina-based oxide (more preferably on the surface). It is particularly preferable that the primary particle level is uniformly supported in the network structure formed of the fibrous alumina-based oxide.
このような排ガス浄化用触媒担体において、前記繊維状アルミナ系酸化物の含有量としては、触媒担体全体に対して２０〜８０質量％が好ましく、２５〜６０質量％がより好ましく、３０〜５０質量％であることが更に好ましい。前記繊維状アルミナ系酸化物の含有量が前記下限未満になると、アルミナによる拡散障壁機能が小さくなり、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が十分に抑制されないため、触媒活性が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。他方、前記繊維状アルミナ系酸化物の含有量が前記上限を超えると、相対的に前記粒子状酸化物の含有量が少なくなるため、酸素吸蔵放出能（ＯＳＣ能）が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。 In such a catalyst carrier for exhaust gas purification, the content of the fibrous alumina-based oxide is preferably 20 to 80% by mass, more preferably 25 to 60% by mass, and 30 to 50% by mass with respect to the entire catalyst carrier. It is more preferably%. When the content of the fibrous alumina-based oxide is less than the lower limit, the diffusion barrier function by alumina becomes small, and the grain growth due to the syntering of the particulate oxide or the noble metal at a high temperature is not sufficiently suppressed, so that the catalytic activity Tends to decrease and the oxygen absorption / release rate (OSC rate) tends to decrease. On the other hand, when the content of the fibrous alumina-based oxide exceeds the upper limit, the content of the particulate oxide is relatively small, so that the oxygen storage / release capacity (OSC capacity) is lowered and the oxygen absorption / release capacity is reduced. The speed (OSC speed) tends to be slow.
また、前記粒子状酸化物の含有量としては、触媒担体全体に対して２０〜８０質量％が好ましく、４０〜７０質量％がより好ましい。前記粒子状酸化物の含有量が前記下限未満になると、酸素吸蔵放出能（ＯＳＣ能）が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。他方、前記粒子状酸化物の含有量が前記上限を超えると、相対的に前記繊維状アルミナ系酸化物の含有量が少なくなるため、アルミナによる拡散障壁機能が小さくなり、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が十分に抑制されず、触媒活性が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。 The content of the particulate oxide is preferably 20 to 80% by mass, more preferably 40 to 70% by mass, based on the entire catalyst carrier. When the content of the particulate oxide is less than the lower limit, the oxygen storage / release ability (OSC ability) tends to decrease, and the oxygen absorption / release rate (OSC rate) tends to decrease. On the other hand, when the content of the particulate oxide exceeds the upper limit, the content of the fibrous alumina-based oxide is relatively small, so that the diffusion barrier function by alumina is reduced and the particulate oxidation at high temperature is performed. Grain growth due to the syntering of substances and noble metals is not sufficiently suppressed, the catalytic activity is lowered, and the oxygen absorption / release rate (OSC rate) tends to be slowed down.
さらに、本発明の排ガス浄化用触媒担体は、細孔直径が３〜５０ｎｍのメソ細孔を有していることが好ましく、このメソ細孔の触媒担体１ｇ当たりの全細孔容量が０．３ｃｍ３／ｇ以上であることが好ましく、０．４ｃｍ３／ｇ以上であることがより好ましい。メソ細孔の全細孔容量が前記下限未満になると、ガスの拡散性が低下するとともに、高温に曝された場合に、粒子状酸化物や貴金属のシンタリングによる粒成長が十分に抑制されず、触媒活性が低下するため、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。なお、メソ細孔の全細孔容量の上限としては特に制限はないが、貴金属と粒子状酸化物等との相互作用を維持させるという観点から、２ｃｍ３／ｇ以下が好ましく、１ｃｍ３／ｇ以下がより好ましい。 Further, the catalyst carrier for exhaust gas purification of the present invention preferably has mesopores having a pore diameter of 3 to 50 nm, and the total pore volume of the mesopores per 1 g of the catalyst carrier is 0.3 cm. it is preferably 3 / g or more, more preferably 0.4 cm 3 / g or more. When the total pore volume of the mesopores is less than the above lower limit, the diffusivity of the gas is lowered, and when exposed to a high temperature, the grain growth due to the sintering of particulate oxides and precious metals is not sufficiently suppressed. Since the catalytic activity is lowered, the oxygen absorption / release rate (OSC rate) tends to be slow. The upper limit of the total pore volume of the mesopores is not particularly limited, but is preferably 2 cm 3 / g or less from the viewpoint of maintaining the interaction between the noble metal and the particulate oxide or the like, and 1 cm 3 / g. The following is more preferable.
また、本発明の排ガス浄化用触媒担体は、細孔直径が５０〜１０００ｎｍのマクロ細孔を有していることが好ましく、このマクロ細孔の触媒担体１ｇ当たりの全細孔容量が０．４ｃｍ３／ｇ以上であることが好ましく、０．５ｃｍ３／ｇ以上であることがより好ましい。マクロ細孔の全細孔容量が前記下限未満になると、排ガス成分の触媒内部への拡散性が低下する傾向にある。なお、マクロ細孔の全細孔容量の上限としては特に制限はないが、排ガス浄化触媒の嵩増大による触媒層の圧力損失の不必要な増大を防止するという観点から、３ｃｍ３／ｇ以下が好ましく、２ｃｍ３／ｇ以下がより好ましい。 Further, the catalyst carrier for exhaust gas purification of the present invention preferably has macropores having a pore diameter of 50 to 1000 nm, and the total pore volume of the macropores per 1 g of the catalyst carrier is 0.4 cm. it is preferably 3 / g or more, more preferably 0.5 cm 3 / g or more. When the total pore volume of the macropores is less than the lower limit, the diffusivity of the exhaust gas component into the catalyst tends to decrease. The upper limit of the total pore capacity of the macropores is not particularly limited, but from the viewpoint of preventing an unnecessary increase in the pressure loss of the catalyst layer due to the increase in the volume of the exhaust gas purification catalyst, 3 cm 3 / g or less is used. Preferably, it is 2 cm 3 / g or less, more preferably.
なお、本発明において、メソ細孔及びマクロ細孔の細孔容量は水銀圧入法により求められる。すなわち、触媒担体に水銀を高圧で注入し、加えた圧力と水銀の注入量との関係を求める。加えた圧力から細孔直径を算出し、水銀の注入量から細孔容量を算出し、これらをプロットして細孔分布曲線を求め、この細孔分布曲線からマクロ細孔の全細孔容量を算出する。 In the present invention, the pore volumes of the mesopores and the macropores are determined by the mercury intrusion method. That is, mercury is injected into the catalyst carrier at high pressure, and the relationship between the applied pressure and the amount of mercury injected is obtained. The pore diameter is calculated from the applied pressure, the pore volume is calculated from the amount of mercury injected, these are plotted to obtain the pore distribution curve, and the total pore volume of the macropores is calculated from this pore distribution curve. calculate.
さらに、本発明の排ガス浄化用触媒担体のＢＥＴ比表面積としては特に制限はないが、１０〜２００ｍ２／ｇが好ましく、２０〜１００ｍ２／ｇがより好ましい。ＢＥＴ比表面積が前記下限未満になると、酸素吸蔵放出能（ＯＳＣ能）が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にあり、他方、前記上限を超えると、触媒担体の嵩が増大し、触媒層の圧力損失が過大になる傾向にある。なお、本発明において、「ＢＥＴ比表面積」は触媒担体の窒素吸着等温線からＢＥＴ等温吸着式を用いて算出することができる。 Further, although no particular restriction on the BET specific surface area of the exhaust gas purifying catalyst carrier of the present invention, preferably 10~200m 2 / g, 20~100m 2 / g is more preferable. When the BET specific surface area is less than the lower limit, the oxygen storage / release capacity (OSC capacity) tends to decrease, and the oxygen absorption / release rate (OSC rate) tends to decrease. On the other hand, when the BET specific surface area exceeds the upper limit, the bulk of the catalyst carrier increases. It tends to increase and the pressure loss of the catalyst layer becomes excessive. In the present invention, the "BET specific surface area" can be calculated from the nitrogen adsorption isotherm of the catalyst carrier using the BET isotherm equation.
〔排ガス浄化用触媒〕
次に、本発明の排ガス浄化用触媒について説明する。本発明の排ガス浄化用触媒は、前記本発明の排ガス浄化用触媒担体と、前記触媒担体に担持されている貴金属とを含有するものである。前記本発明の排ガス浄化用触媒担体が、容量の大きな細孔（特に、メソ細孔）を有し、高温下においても細孔容量（特に、メソ細孔の細孔容量）が変化しにくいものであるため、本発明の排ガス浄化用触媒は、高温に曝された場合であっても、ガスの拡散性が高く、高い酸素吸放出速度（ＯＳＣ速度）を示す。また、細孔容量が大きいため、貴金属のシンタリングによる粒成長が起こりにくく、高い触媒活性を示す。
[Catalyst for purifying exhaust gas]
Next, the exhaust gas purification catalyst of the present invention will be described. The exhaust gas purification catalyst of the present invention contains the exhaust gas purification catalyst carrier of the present invention and a noble metal supported on the catalyst carrier. The catalyst carrier for exhaust gas purification of the present invention has pores having a large capacity (particularly, mesopores), and the pore capacity (particularly, the pore capacity of the mesopores) does not easily change even at a high temperature. Therefore, the exhaust gas purification catalyst of the present invention has high gas diffusivity and exhibits a high oxygen absorption / release rate (OSC rate) even when exposed to a high temperature. In addition, since the pore capacity is large, grain growth due to sintering of precious metals is unlikely to occur, and high catalytic activity is exhibited.
本発明の排ガス浄化用触媒において、前記貴金属としては、パラジウム、ロジウム、白金、イリジウム、ルテニウム等が挙げられる。これらの貴金属は１種を単独で使用しても２種以上を併用してもよい。これらの貴金属のうち、排ガス浄化用触媒としての活性の観点から、パラジウム、ロジウム、白金が好ましい。貴金属の担持量としては特に制限はなく、得られる触媒の用途に応じて適宜調整されるが、排ガス浄化用触媒担体１００質量部に対して０．１〜１０質量部が好ましい。 In the exhaust gas purification catalyst of the present invention, examples of the precious metal include palladium, rhodium, platinum, iridium, ruthenium and the like. These precious metals may be used alone or in combination of two or more. Of these precious metals, palladium, rhodium, and platinum are preferable from the viewpoint of activity as a catalyst for purifying exhaust gas. The amount of the noble metal supported is not particularly limited and is appropriately adjusted according to the use of the obtained catalyst, but is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the catalyst carrier for exhaust gas purification.
本発明の排ガス浄化用触媒において、その形態は特に制限されず、例えば、前記触媒を粒子の形態のまま用いてもよく、或いは、前記触媒を基材に担持したハニカム形状のモノリス触媒や、前記触媒をペレット形状に成形したペレット触媒の形態等として用いてもよい。ここで用いられる基材も特に制限されず、パティキュレートフィルタ基材（ＤＰＦ基材）、モノリス状基材、ペレット状基材、プレート状基材等を好適に採用することができる。また、このような基材の材質も特に制限されないが、コーディエライト、炭化ケイ素、チタン酸アルミ、ムライト等のセラミックスからなる基材や、クロム及びアルミニウムを含むステンレススチール等の金属からなる基材を好適に採用することができる。さらに、本発明の排ガス浄化用触媒においては、その効果を損なわない範囲で各種触媒に用いることが可能な他の成分が適宜担持されていてもよい。 The form of the exhaust gas purification catalyst of the present invention is not particularly limited, and for example, the catalyst may be used in the form of particles, a honeycomb-shaped monolith catalyst in which the catalyst is supported on a base material, or the above. It may be used as a form of a pellet catalyst obtained by molding the catalyst into a pellet shape. The base material used here is not particularly limited, and a particulate filter base material (DPF base material), a monolith-like base material, a pellet-like base material, a plate-like base material, and the like can be preferably used. The material of such a base material is not particularly limited, but a base material made of ceramics such as cordierite, silicon carbide, aluminum titanate, and mullite, and a base material made of a metal such as stainless steel containing chromium and aluminum. Can be preferably adopted. Further, in the exhaust gas purification catalyst of the present invention, other components that can be used for various catalysts may be appropriately supported as long as the effect is not impaired.
〔排ガス浄化用触媒担体の製造方法〕
次に、本発明の排ガス浄化用触媒担体の製造方法について説明する。本発明の排ガス浄化用触媒担体の製造方法は、粒子状酸化物及びその前駆体のうちの少なくとも一方を含有するナノコロイドと、平均短径が１〜２０ｎｍかつ平均アスペクト比が１０以上である繊維状アルミナ系酸化物とを混合してナノコロイドゾルを調製し、このナノコロイドゾルにアミン化合物を添加した後、生成した固体成分に乾燥処理及び焼成処理を施して触媒担体を得る方法である。
[Manufacturing method of catalyst carrier for exhaust gas purification]
Next, a method for producing the catalyst carrier for exhaust gas purification of the present invention will be described. The method for producing a catalyst carrier for purifying exhaust gas of the present invention is a nanocolloid containing at least one of a particulate oxide and a precursor thereof, and a fiber having an average minor axis of 1 to 20 nm and an average aspect ratio of 10 or more. This is a method in which a nanocolloidal sol is prepared by mixing with a state alumina-based oxide, an amine compound is added to the nanocolloidal sol, and then the produced solid component is subjected to a drying treatment and a firing treatment to obtain a catalyst carrier.
本発明の排ガス浄化用触媒担体の製造に用いられる、粒子状酸化物及びその前駆体のうちの少なくとも一方を含有するナノコロイドとしては特に制限はなく、例えば、特開２０１０−２２８９４号公報に記載の超微粒子の製造方法に従って調製することができる。すなわち、所望の粒子状酸化物の前駆体（例えば、酢酸塩、硝酸塩、塩化物、硫酸塩、亜硫酸塩、無機錯塩等の所望の金属の塩）を含有する原料溶液と、中和剤（例えば、エチレンジアミン、モノエタノールアミン、ジエタノールアミン、ポリエチレンイミン等のアミン化合物）を含有する中和剤溶液とを混合することによって前記ナノコロイドが得られる。このとき、前記原料溶液と前記中和剤溶液とを高せん断速度（例えば、５０００〜４００００ｓｅｃ−１）下において混合することによって、微細かつ均一性の高いナノコロイドが得られる。このような高せん断速度下における混合は、例えば、特開２０１０−２２８９４号公報に記載の超微粒子の製造装置を使用することによって行うことができる。 The nanocolloid containing at least one of the particulate oxide and its precursor used in the production of the catalyst carrier for exhaust gas purification of the present invention is not particularly limited, and is described in, for example, JP-A-2010-22894. It can be prepared according to the method for producing ultrafine particles of. That is, a raw material solution containing a desired particulate oxide precursor (eg, a salt of the desired metal such as acetate, nitrate, chloride, sulfate, sulfite, inorganic complex salt) and a neutralizing agent (eg, salt). , Ethylenediamine, monoethanolamine, diethanolamine, polyethyleneimine and other amine compounds) are mixed with a neutralizing agent solution to obtain the nanocolloid. At this time, by mixing the raw material solution and the neutralizing agent solution at a high shear rate (for example, 5000 to 40,000 sec -1 ), a fine and highly uniform nanocolloid can be obtained. Mixing under such a high shear rate can be performed, for example, by using the apparatus for producing ultrafine particles described in JP-A-2010-22894.
また、本発明の排ガス浄化用触媒担体の製造方法においては、平均短径が１〜２０ｎｍ（好ましくは３〜１０ｎｍ、より好ましくは３〜８ｎｍ）であり、平均アスペクト比が１０以上（好ましくは２０以上、より好ましくは２５以上、更に好ましくは５０以上）である繊維状アルミナ系酸化物であれば特に制限なく、原料として使用することができるが、平均アスペクト比が大きい繊維状アルミナ系酸化物を含有する触媒担体が得られるという観点から、平均アスペクト比が２００以上（特に好ましくは、３００以上）の繊維状アルミナ系酸化物を原料として使用することが更に好ましい。このような繊維状アルミナ系酸化物原料としては、市販のアルミナナノファイバー等を使用することができる。また、このような原料の繊維状アルミナ系酸化物の平均アスペクト比や平均短径を調整することによって、得られる触媒担体において、繊維状アルミナ系酸化物により形成される構造（好ましくは、網目状構造細孔）を適宜制御することが可能であり、例えば、細孔（特に、メソ細孔）の大きさを適宜調整することができる。 Further, in the method for producing a catalyst carrier for purifying exhaust gas of the present invention, the average minor axis is 1 to 20 nm (preferably 3 to 10 nm, more preferably 3 to 8 nm), and the average aspect ratio is 10 or more (preferably 20). As described above, any fibrous alumina-based oxide having a value of 25 or more, more preferably 50 or more) can be used as a raw material without particular limitation, but a fibrous alumina-based oxide having a large average aspect ratio can be used. From the viewpoint of obtaining a catalyst carrier contained therein, it is more preferable to use a fibrous alumina-based oxide having an average aspect ratio of 200 or more (particularly preferably 300 or more) as a raw material. As such a fibrous alumina-based oxide raw material, commercially available alumina nanofibers and the like can be used. Further, in the catalyst carrier obtained by adjusting the average aspect ratio and the average minor axis of the fibrous alumina-based oxide of such a raw material, a structure formed by the fibrous alumina-based oxide (preferably in a network shape). The structural pores) can be appropriately controlled, and for example, the size of the pores (particularly, mesopores) can be appropriately adjusted.
本発明の排ガス浄化用触媒担体の製造方法においては、先ず、前記ナノコロイドと前記繊維状アルミナ系酸化物とを混合してナノコロイドゾルを調製する。前記ナノコロイドと前記繊維状アルミナ系酸化物との混合方法としては特に制限はなく、プロペラ攪拌による混合であっても、特開２０１０−２２８９４号公報に記載の超微粒子の製造装置を用いた混合であってもよいが、平均アスペクト比が大きい繊維状アルミナ系酸化物を含有する触媒担体が得られるという観点から、プロペラ攪拌による混合が好ましい。 In the method for producing a catalyst carrier for exhaust gas purification of the present invention, first, the nanocolloid and the fibrous alumina-based oxide are mixed to prepare a nanocolloid sol. The method for mixing the nanocolloid and the fibrous alumina-based oxide is not particularly limited, and even if the mixture is mixed by stirring with a propeller, the mixture is mixed using the ultrafine particle manufacturing apparatus described in JP-A-2010-22894. However, from the viewpoint of obtaining a catalyst carrier containing a fibrous alumina-based oxide having a large average aspect ratio, mixing by propeller stirring is preferable.
また、前記ナノコロイドと前記繊維状アルミナ系酸化物との混合割合としては、粒子状酸化物換算の前記ナノコロイド配合量と前記繊維状アルミナ系酸化物配合量との合計量に対して、前記繊維状アルミナ系酸化物の配合量が２０〜８０質量％であることが好ましく、２５〜６０質量％であることがより好ましく、３０〜５０質量％であることが更に好ましい。前記繊維状アルミナ系酸化物の配合量が前記下限未満になると、得られる触媒担体において、アルミナによる拡散障壁機能が小さくなり、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が十分に抑制されないため、触媒活性が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。他方、前記繊維状アルミナ系酸化物の配合量が前記上限を超えると、得られる触媒担体において、相対的に前記粒子状酸化物の含有量が少なくなるため、酸素吸蔵放出能（ＯＳＣ能）が低下し、酸素吸放出速度（ＯＳＣ速度）が遅くなる傾向にある。 The mixing ratio of the nanocolloid and the fibrous alumina-based oxide is the same as the total amount of the nanocolloid blended amount and the fibrous alumina-based oxide blended amount in terms of particulate oxide. The blending amount of the fibrous alumina-based oxide is preferably 20 to 80% by mass, more preferably 25 to 60% by mass, and further preferably 30 to 50% by mass. When the blending amount of the fibrous alumina-based oxide is less than the above lower limit, the diffusion barrier function by alumina becomes small in the obtained catalyst carrier, and the grain growth by syntaring of the particulate oxide or the noble metal at a high temperature is sufficient. Since it is not suppressed, the catalytic activity tends to decrease, and the oxygen absorption / release rate (OSC rate) tends to decrease. On the other hand, when the blending amount of the fibrous alumina-based oxide exceeds the upper limit, the content of the particulate oxide is relatively small in the obtained catalyst carrier, so that the oxygen storage / release capacity (OSC capacity) is increased. It tends to decrease and the oxygen absorption / release rate (OSC rate) tends to decrease.
次に、このようにして得られたナノコロイドゾルにアミン化合物を添加して固体成分を生成させる。前記アミン化合物としては、エチレンジアミン、モノエタノールアミン、ジエタノールアミン、ポリエチレンイミン等が挙げられる。 Next, an amine compound is added to the nanocolloidal sol thus obtained to produce a solid component. Examples of the amine compound include ethylenediamine, monoethanolamine, diethanolamine, polyethyleneimine and the like.
その後、得られた固体成分に乾燥処理及び焼成処理を施して、所望の焼成物（触媒担体）を得る。乾燥処理及び焼成処理の条件としては特に制限はないが、乾燥温度としては１００〜２００℃が好ましく、乾燥時間としては６〜２４時間が好ましい。また、焼成温度としては３００〜１０００℃が好ましく、焼成時間としては５〜２４時間が好ましい。 Then, the obtained solid component is subjected to a drying treatment and a firing treatment to obtain a desired fired product (catalyst carrier). The conditions for the drying treatment and the firing treatment are not particularly limited, but the drying temperature is preferably 100 to 200 ° C., and the drying time is preferably 6 to 24 hours. The firing temperature is preferably 300 to 1000 ° C., and the firing time is preferably 5 to 24 hours.
以下、実施例及び比較例に基づいて本発明をより具体的に説明するが、本発明は以下の実施例に限定されるものではない。 Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples, but the present invention is not limited to the following Examples.
（実施例１）
先ず、硝酸アンモニウムセリウム（和光純薬工業株式会社製）４１．１２ｇ、オキシ硝酸ジルコニル水溶液（キャタラー株式会社製、ＺｒＯ２換算濃度：１８質量％）９４．６７ｇ、硝酸イットリウム（関東化学株式会社製）３．２１ｇ、硝酸ランタン（和光純薬工業株式会社製）４．８４ｇ、及びアミノヘキサン酸（和光純薬工業株式会社製）５２．４ｇの混合物にイオン交換水を添加して総量１Ｌの原料水溶液を調製した。また、中和剤であるエチレンジアミン（和光純薬工業株式会社製）１８ｇにイオン交換水を添加して総量１Ｌの中和剤水溶液を調製した。
(Example 1)
First, 41.12 g of ammonium cerium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.), 94.67 g of an aqueous solution of zirconyl oxynitrate (manufactured by Cataler Co., Ltd., ZrO 2 equivalent concentration: 18% by mass), yttrium nitrate (manufactured by Kanto Chemical Industries, Ltd.) 3 Add ion-exchanged water to a mixture of .21 g, lanthanate nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) 4.84 g, and aminohexanoic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 52.4 g to make a total of 1 L of the raw material aqueous solution. Prepared. Further, ion-exchanged water was added to 18 g of ethylenediamine (manufactured by Wako Pure Chemical Industries, Ltd.) as a neutralizing agent to prepare a neutralizing agent aqueous solution having a total amount of 1 L.
次に、特開２０１０−２２８９４号公報に記載の超微粒子の製造装置（スーパーアジテーションリアクター）を用い、ローターを１００００ｒｐｍの回転速度で回転させながら、前記原料水溶液１Ｌと前記中和剤水溶液１Ｌとをそれぞれ１０ｍｌ／ｍｉｎの供給速度で供給して混合し、淡黄色のセリア−ジルコニア−ランタナ−イットリアのナノコロイド（ＣＺＬＹナノコロイド）溶液を調製した。また、アルミナナノファイバーゾル（川研ファインケミカル株式会社製「Ｆ−３０００」、短径：４ｎｍ、長径：３０００ｎｍ）２７２．４２ｇにイオン交換水を添加して総量１Ｌのアルミナナノファイバーゾルを調製した。 Next, using the ultrafine particle manufacturing apparatus (super agitation reactor) described in Japanese Patent Application Laid-Open No. 2010-22894, 1 L of the raw material aqueous solution and 1 L of the neutralizing agent aqueous solution were mixed while rotating the rotor at a rotation speed of 10000 rpm. Each was fed at a feed rate of 10 ml / min and mixed to prepare a pale yellow ceria-zirconia-lanthana-yttria nanocolloid (CZLY nanocolloid) solution. Further, ion-exchanged water was added to 272.42 g of an alumina nanofiber sol (“F-3000” manufactured by Kawaken Fine Chemical Co., Ltd., minor axis: 4 nm, major axis: 3000 nm) to prepare an alumina nanofiber sol having a total amount of 1 L.
次に、特開２０１０−２２８９４号公報に記載の超微粒子の製造装置（スーパーアジテーションリアクター）を用い、ローターを３４００ｒｐｍの回転速度で回転させながら、前記ＣＺＬＹナノコロイド溶液１Ｌと前記アルミナナノファイバーゾル１Ｌとをそれぞれ１０ｍｌ／ｍｉｎの供給速度で供給して混合し、前記アルミナナノファイバーと前記ＣＺＬＹナノコロイドとを含有するナノコロイドゾルを調製した。 Next, using the ultrafine particle manufacturing apparatus (super agitation reactor) described in Japanese Patent Application Laid-Open No. 2010-22894, the CZLY nanocolloidal solution 1L and the alumina nanofiber sol 1L are rotated at a rotation speed of 3400 rpm. And were supplied at a supply rate of 10 ml / min and mixed to prepare a nanocolloidal sol containing the alumina nanofibers and the CZLY nanocolloids.
得られたナノコロイドゾルにエチレンジアミンを滴下した後、遠心分離と水洗とを２回ずつ繰返し、さらに、デカンテーションを行なって固体成分を回収した。得られた固体成分をポリエチレングリコール６０００の水溶液（濃度０．６モル／Ｌ）５００ｍｌに再分散させた後、得られたゾルを、大気中、１００℃で１０時間、さらに２５０℃で３時間仮焼して乾燥及び脱脂した。得られた仮焼粉末をアルミナるつぼに入れ、大気中、３５０℃で１２時間、さらに９００℃で５時間焼成した。その後、得られた焼成粉末の粒径を粉砕と篩分けにより７５μｍ以下に調整した。この焼成粉末において、アルミナナノファイバーの含有量は焼成粉末全体に対して３０質量％であり、前記ＣＺＬＹの含有量は焼成粉末全体に対して７０質量％であった。 After dropping ethylenediamine into the obtained nanocolloidal sol, centrifugation and washing with water were repeated twice, and further decantation was performed to recover the solid component. After redispersing the obtained solid component in 500 ml of an aqueous solution of polyethylene glycol 6000 (concentration 0.6 mol / L), the obtained sol was tentatively prepared in the air at 100 ° C. for 10 hours and further at 250 ° C. for 3 hours. It was baked, dried and degreased. The obtained calcined powder was placed in an alumina crucible and calcined in the air at 350 ° C. for 12 hours and further at 900 ° C. for 5 hours. Then, the particle size of the obtained calcined powder was adjusted to 75 μm or less by pulverization and sieving. In this calcined powder, the content of alumina nanofibers was 30% by mass with respect to the entire calcined powder, and the content of CZLY was 70% by mass with respect to the entire calcined powder.
（実施例２）
アルミナファイバーゾルとして、川研ファインケミカル株式会社製「Ｆ−１０００」（短径：４ｎｍ、長径：１４００ｎｍ）２７２．４２ｇを用い、前記ＣＺＬＹナノコロイド溶液１Ｌと前記アルミナナノファイバーゾル１Ｌとを、プロペラ攪拌機を用いて２００ｒｐｍの攪拌速度で撹拌した以外は実施例１と同様にして、粒径が７５μｍ以下の焼成粉末を得た。この焼成粉末において、アルミナナノファイバーの含有量は焼成粉末全体に対して３０質量％であり、前記ＣＺＬＹの含有量は焼成粉末全体に対して７０質量％であった。
(Example 2)
As the alumina fiber sol, 272.42 g of "F-1000" (minor axis: 4 nm, major axis: 1400 nm) manufactured by Kawaken Fine Chemical Co., Ltd. was used, and 1 L of the CZLY nanocolloidal solution and 1 L of the alumina nanofiber sol were mixed with a propeller stirrer. A calcined powder having a particle size of 75 μm or less was obtained in the same manner as in Example 1 except that the mixture was stirred at a stirring speed of 200 rpm. In this calcined powder, the content of alumina nanofibers was 30% by mass with respect to the entire calcined powder, and the content of CZLY was 70% by mass with respect to the entire calcined powder.
（実施例３）
前記ＣＺＬＹナノコロイド溶液１Ｌと前記アルミナナノファイバーゾル１Ｌとを、プロペラ攪拌機を用いて２００ｒｐｍの攪拌速度で撹拌した以外は実施例１と同様にして、粒径が７５μｍ以下の焼成粉末を得た。この焼成粉末において、アルミナナノファイバーの含有量は焼成粉末全体に対して３０質量％であり、前記ＣＺＬＹの含有量は焼成粉末全体に対して７０質量％であった。
(Example 3)
A fired powder having a particle size of 75 μm or less was obtained in the same manner as in Example 1 except that 1 L of the CZLY nanocolloidal solution and 1 L of the alumina nanofiber sol were stirred at a stirring speed of 200 rpm using a propeller stirrer. In this calcined powder, the content of alumina nanofibers was 30% by mass with respect to the entire calcined powder, and the content of CZLY was 70% by mass with respect to the entire calcined powder.
（比較例１）
先ず、硝酸アルミニウム（和光純薬工業株式会社製）１００．１３ｇ、硝酸アンモニウムセリウム（和光純薬工業株式会社製）４１．１２ｇ、オキシ硝酸ジルコニル水溶液（キャタラー株式会社製、ＺｒＯ２換算濃度：１８質量％）９４．６７ｇ、硝酸イットリウム（関東化学株式会社製）３．２１ｇ、硝酸ランタン（和光純薬工業株式会社製）４．８４ｇ、及びアミノヘキサン酸（和光純薬工業株式会社製）５２．４ｇの混合物にイオン交換水を添加して総量１Ｌの原料水溶液を調製した。また、中和剤であるエチレンジアミン（和光純薬工業株式会社製）２５ｇにイオン交換水を添加して総量１Ｌの中和剤水溶液を調製した。
(Comparative Example 1)
First, aluminum nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) 100.13 g, ammonium cerium nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) 41.12 g, aqueous solution of zirconyl oxynitrate (manufactured by Cataler Co., Ltd., ZrO 2 equivalent concentration: 18% by mass) ) 94.67 g, ittrium nitrate (manufactured by Kanto Chemical Industries, Ltd.) 3.21 g, lanthanate nitrate (manufactured by Wako Pure Chemical Industries, Ltd.) 4.84 g, and aminohexanoic acid (manufactured by Wako Pure Chemical Industries, Ltd.) 52.4 g. Ion-exchanged water was added to the mixture to prepare a total amount of 1 L of the raw material aqueous solution. Further, ion-exchanged water was added to 25 g of ethylenediamine (manufactured by Wako Pure Chemical Industries, Ltd.) as a neutralizing agent to prepare a neutralizing agent aqueous solution having a total amount of 1 L.
次に、特開２０１０−２２８９４号公報に記載の超微粒子の製造装置（スーパーアジテーションリアクター）を用い、ローターを３４００ｒｐｍの回転速度で回転させながら、前記原料水溶液１Ｌと前記中和剤水溶液１Ｌとをそれぞれ１０ｍｌ／ｍｉｎの供給速度で供給して混合し、アルミナナノコロイドとセリア−ジルコニア−ランタナ−イットリアのナノコロイド（ＣＺＬＹナノコロイド）とを含有する淡黄色のナノコロイドゾルを調製した。 Next, using the ultrafine particle manufacturing apparatus (super agitation reactor) described in JP-A-2010-22894, 1 L of the raw material aqueous solution and 1 L of the neutralizing agent aqueous solution were mixed while rotating the rotor at a rotation speed of 3400 rpm. Each was supplied at a supply speed of 10 ml / min and mixed to prepare a pale yellow nanocolloidal sol containing an alumina nanocolloid and a ceria-zirconia-lanthana-itria nanocolloid (CZLY nanocolloid).
得られたナノコロイドゾルにエチレンジアミンを滴下した後、遠心分離と水洗とを２回ずつ繰返し、さらに、デカンテーションを行なって固体成分を回収した。得られた固体成分をポリエチレングリコール６０００の水溶液（濃度０．６モル／Ｌ）５００ｍｌに再分散させた後、得られたゾルを、大気中、１００℃で１０時間、さらに２５０℃で３時間仮焼して乾燥及び脱脂した。得られた仮焼粉末をアルミナるつぼに入れ、大気中、３５０℃で１２時間、さらに９００℃で５時間焼成した。その後、得られた焼成粉末の粒径を粉砕と篩分けにより７５μｍ以下に調整した。この焼成粉末において、アルミナの含有量は焼成粉末全体に対して３０質量％であり、前記ＣＺＬＹの含有量は焼成粉末全体に対して７０質量％であった。 After dropping ethylenediamine into the obtained nanocolloidal sol, centrifugation and washing with water were repeated twice, and further decantation was performed to recover the solid component. After redispersing the obtained solid component in 500 ml of an aqueous solution of polyethylene glycol 6000 (concentration 0.6 mol / L), the obtained sol was tentatively prepared in the air at 100 ° C. for 10 hours and further at 250 ° C. for 3 hours. It was baked, dried and degreased. The obtained calcined powder was placed in an alumina crucible and calcined in the air at 350 ° C. for 12 hours and further at 900 ° C. for 5 hours. Then, the particle size of the obtained calcined powder was adjusted to 75 μm or less by pulverization and sieving. In this calcined powder, the content of alumina was 30% by mass with respect to the entire calcined powder, and the content of CZLY was 70% by mass with respect to the entire calcined powder.
（比較例２）
前記固体成分をポリエチレングリコール６０００の水溶液（濃度０．６モル／Ｌ）５００ｍｌに再分散させたゾルを、仮焼する前に、１５０℃で１２時間保温して熟成させた以外は比較例１と同様にして、粒径が７５μｍ以下の焼成粉末を得た。この焼成粉末において、アルミナの含有量は焼成粉末全体に対して３０質量％であり、前記ＣＺＬＹの含有量は焼成粉末全体に対して７０質量％であった。
(Comparative Example 2)
A sol obtained by redispersing the solid component in 500 ml of an aqueous solution of polyethylene glycol 6000 (concentration: 0.6 mol / L) was kept warm at 150 ° C. for 12 hours and aged before calcining. Similarly, a calcined powder having a particle size of 75 μm or less was obtained. In this calcined powder, the content of alumina was 30% by mass with respect to the entire calcined powder, and the content of CZLY was 70% by mass with respect to the entire calcined powder.
＜ＴＥＭ観察、平均粒子径及び平均アスペクト比の測定＞
実施例及び比較例で得られた各焼成粉末を、大気中、１１００℃で５時間加熱した後、透過型電子顕微鏡（日本電子株式会社製「ＪＥＭ−ＡＲＭ２００Ｆ」）を用いて観察した。図４Ａは実施例１で得られた焼成粉末のＴＥＭ写真であり、図４Ｂは図４Ａを拡大したＴＥＭ写真であり、図５Ａは比較例２で得られた焼成粉末のＴＥＭ写真であり、図５Ｂは図５Ａを拡大したＴＥＭ写真である。
<TEM observation, measurement of average particle size and average aspect ratio>
Each calcined powder obtained in Examples and Comparative Examples was heated in the air at 1100 ° C. for 5 hours and then observed using a transmission electron microscope (“JEM-ARM200F” manufactured by JEOL Ltd.). FIG. 4A is a TEM photograph of the calcined powder obtained in Example 1, FIG. 4B is an enlarged TEM photograph of FIG. 4A, and FIG. 5A is a TEM photograph of the calcined powder obtained in Comparative Example 2. 5B is an enlarged TEM photograph of FIG. 5A.
図４Ａ及び図４Ｂに示したＴＥＭ写真から明らかなように、実施例１で得られた焼成粉末においては、図１に示したように、アルミナナノファイバー（ＴＥＭ写真においては筋状の薄灰色部分）が網目状構造を形成しており、この網目状のアルミナナノファイバーにＣＺＬＹ粒子（ＴＥＭ写真においては黒色部分）が担持されていることが確認された。また、実施例２〜３で得られた焼成粉末についても同様に、網目状のアルミナナノファイバーにＣＺＬＹ粒子が担持されていた。 As is clear from the TEM photographs shown in FIGS. 4A and 4B, in the calcined powder obtained in Example 1, as shown in FIG. 1, alumina nanofibers (streak-like light gray portions in the TEM photograph). ) Formed a network structure, and it was confirmed that CZLY particles (black portion in the TEM photograph) were supported on the network-like alumina nanofibers. Similarly, in the calcined powders obtained in Examples 2 to 3, CZLY particles were supported on the mesh-like alumina nanofibers.
一方、図５Ａ及び図５Ｂに示したＴＥＭ写真から明らかなように、比較例２で得られた焼成粉末においては、図２に示したように、針状のアルミナ粒子（ＴＥＭ写真においては薄灰色部分）と球状のＣＺＬＹ粒子（ＴＥＭ写真においては黒色部分）とが凝集していることが確認された。また、比較例１で得られた焼成粉末においては、図３に示したように、扁球状のアルミナ粒子と球状のＣＺＬＹ粒子とが凝集していることが確認された。 On the other hand, as is clear from the TEM photographs shown in FIGS. 5A and 5B, in the calcined powder obtained in Comparative Example 2, as shown in FIG. 2, needle-shaped alumina particles (light gray in the TEM photograph). Part) and spherical CZLY particles (black part in the TEM photograph) were confirmed to be agglomerated. Further, in the calcined powder obtained in Comparative Example 1, as shown in FIG. 3, it was confirmed that the oblate spherical alumina particles and the spherical CZLY particles were agglomerated.
また、得られたＴＥＭ写真において、無作為に１０個のアルミナナノファイバー又はアルミナ粒子を抽出し、各アルミナナノファイバー又はアルミナ粒子の長軸方向の長さ（長径）及び長軸方向に垂直な方向の長さ（短径）を測定し、抽出した１０個のアルミナナノファイバー又はアルミナ粒子についての平均長径及び平均短径を求め、さらに、平均アスペクト比（＝平均長径／平均短径）を算出した。その結果を表１に示す。 Further, in the obtained TEM photograph, 10 alumina nanofibers or alumina particles were randomly extracted, and the length (major axis) of each alumina nanofiber or alumina particle in the major axis direction and the direction perpendicular to the major axis direction. The average major axis and the average minor axis of the extracted 10 alumina nanofibers or alumina particles were obtained, and the average aspect ratio (= average major axis / average minor axis) was calculated. .. The results are shown in Table 1.
さらに、得られたＴＥＭ写真において、無作為に１０個のＣＺＬＹ一次粒子を抽出し、各ＣＺＬＹ一次粒子の長軸方向の長さ（長径）及び長軸方向に垂直な方向の長さ（短径）を測定し、長径と短径との算術平均値をその一次粒子の粒子径とし、抽出した１０個のＣＺＬＹ一次粒子の平均粒子径（平均一次粒子径）を求めた。さらに、抽出した１０個のＣＺＬＹ一次粒子についての平均長径及び平均短径を求め、平均アスペクト比（＝平均長径／平均短径）を算出した。その結果を表１に示す。 Further, in the obtained TEM photograph, 10 CZLY primary particles were randomly extracted, and the length (major axis) of each CZLY primary particle in the major axis direction and the length in the direction perpendicular to the major axis direction (minor axis). ) Was measured, and the arithmetic mean value of the major axis and the minor axis was used as the particle size of the primary particles, and the average particle size (average primary particle size) of the 10 extracted CZLY primary particles was determined. Further, the average major axis and the average minor axis of the 10 extracted CZLY primary particles were obtained, and the average aspect ratio (= average major axis / average minor axis) was calculated. The results are shown in Table 1.
＜細孔容量の測定＞
実施例及び比較例で得られた各焼成粉末を大気中、１１００℃で５時間加熱した後、細孔分布測定装置（株式会社島津製作所・マイクロメリティックス社製「オートポア９５２０」）を用いて水銀圧入法により前記焼成粉末の細孔分布曲線を求めた。得られた細孔分布曲線に基づいて、細孔直径が３〜５０ｎｍのメソ細孔の触媒担体１ｇ当たりの全細孔容量及び細孔直径が５０〜１０００ｎｍのマクロ細孔の触媒担体１ｇ当たりの全細孔容量をそれぞれ求めた。その結果を表１に示す。
<Measurement of pore volume>
After heating each calcined powder obtained in Examples and Comparative Examples at 1100 ° C. for 5 hours in the air, a pore distribution measuring device (“Autopore 9520” manufactured by Shimadzu Corporation and Micromeritix Co., Ltd.) was used. The pore distribution curve of the calcined powder was obtained by the mercury intrusion method. Based on the obtained pore distribution curve, the total pore volume per 1 g of the catalyst carrier of mesopores having a pore diameter of 3 to 50 nm and the total pore volume per 1 g of the catalyst carrier of macropores having a pore diameter of 50 to 1000 nm. The total pore capacity was determined respectively. The results are shown in Table 1.
＜触媒調製＞
実施例及び比較例で得られた各焼成粉末を硝酸パラジウム水溶液に浸漬した後、蒸発乾固させることによって、前記焼成粉末にパラジウムを担持させた（Ｐｄ担持量：焼成粉末１００質量部に対して０．４２質量部）。得られたパラジウム担持焼成粉末を大気中で自然乾燥させた後、大気中、３００℃で５時間焼成した。その後、１ｔの静水圧プレス成形を行い、得られた成形体に粉砕及び篩分けを施して、粒径が０．５〜１ｍｍの排ガス浄化用触媒ペレットを得た。
<Catalyst preparation>
Palladium was supported on the calcined powder by immersing each calcined powder obtained in Examples and Comparative Examples in an aqueous solution of palladium nitrate and then evaporating to dryness (Pd supported amount: 100 parts by mass of calcined powder). 0.42 parts by mass). The obtained palladium-supported calcined powder was air-dried in the air and then calcined in the air at 300 ° C. for 5 hours. Then, 1 ton of hydrostatic press molding was performed, and the obtained molded product was pulverized and sieved to obtain an exhaust gas purification catalyst pellet having a particle size of 0.5 to 1 mm.
＜耐久試験＞
得られた排ガス浄化用触媒ペレット１．５ｇを反応管に充填し、リッチガス〔Ｈ２（２ｖｏｌ％）＋ＣＯ２（１０ｖｏｌ％）＋Ｎ２（８８ｖｏｌ％）〕及びリーンガス〔Ｏ２（１ｖｏｌ％）＋ＣＯ２（１０ｖｏｌ％）＋Ｎ２（８９ｖｏｌ％）〕を交互に５分間ずつ切り替えながら前記反応管にガス流量１．６７Ｌ／ｍｉｎ、温度１１００℃で５時間流通させて耐久試験を行なった。
<Durability test>
The reaction tube was filled with 1.5 g of the obtained catalyst pellets for purifying exhaust gas, and rich gas [H 2 ( 2 vol%) + CO 2 (10 vol%) + N 2 (88 vol%)] and lean gas [O 2 (1 vol%) + CO 2 (10 vol%) + N 2 (89 vol%)] was alternately switched for 5 minutes and passed through the reaction tube at a gas flow rate of 1.67 L / min and a temperature of 1100 ° C. for 5 hours to perform a durability test.
＜結晶子径の測定＞
耐久試験後の排ガス浄化用触媒ペレットのＸ線回折パターンを、粉末Ｘ線回折装置（リガク社製、商品名「ＲＩＮＴ−２２００」を用いて測定した。得られたＸ線回折パターンにおけるＰｄ粒子の（１１１）面に由来するピークの半値幅からデバイ・シェラーの式を用いてＰｄの結晶子径を算出した。その結果を表１に示す。
<Measurement of crystallite diameter>
The X-ray diffraction pattern of the catalyst pellet for exhaust gas purification after the durability test was measured using a powder X-ray diffractometer (manufactured by Rigaku Co., Ltd., trade name "RINT-2200"). The crystallite diameter of Pd was calculated from the half-price width of the peak derived from the (111) plane using the Debai Scheller's equation. The results are shown in Table 1.
＜ＯＳＣ速度の測定＞
耐久試験後の排ガス浄化用触媒ペレット０．５ｇを反応管に充填し、リッチガス〔ＣＯ（２ｖｏｌ％）＋Ｎ２（９８ｖｏｌ％）〕及びリーンガス〔Ｏ２（１ｖｏｌ％）＋Ｎ２（９９ｖｏｌ％）〕を交互に３分間ずつ切り替えながら前記反応管にガス流量１０Ｌ／ｍｉｎ、温度５００℃で流通させ、リッチガス導入直後の５秒間に生成するＣＯ２量を測定し、得られたＣＯ２量から触媒１ｇ当たりの酸素吸放出速度を算出した。その結果を表１に示す。
<Measurement of OSC speed>
The reaction tube is filled with 0.5 g of catalyst pellets for purifying exhaust gas after the durability test, and rich gas [CO ( 2 vol%) + N 2 (98 vol%)] and lean gas [O 2 (1 vol%) + N 2 (99 vol%)] are added. alternately 3 minutes each gas into the reaction tube while switching the flow rate 10L / min, was circulated at a temperature 500 ° C., measured amount of CO 2 generated in 5 seconds after rich gas introduced, per catalyst 1g from the obtained amount of CO 2 The oxygen absorption / release rate of was calculated. The results are shown in Table 1.
表１に示したように、繊維状のアルミナ系酸化物（アルミナナノファイバー）に粒子状酸化物（ＣＺＬＹ粒子）が担持されている焼成粉末からなる触媒担体（実施例１〜３）は、扁球状のアルミナ粒子と球状のＣＺＬＹ粒子との凝集体からなる触媒担体（比較例１）や針状のアルミナ粒子と球状のＣＺＬＹ粒子との凝集体からなる触媒担体（比較例２）に比べて、メソ細孔の細孔容量が大きいことがわかった。これは、本発明の排ガス浄化用触媒担体（実施例１〜３）において、繊維状のアルミナ系酸化物によって網目状構造が形成されているためと推察される。 As shown in Table 1, the catalyst carrier (Examples 1 to 3) made of calcined powder in which particulate oxides (CZLY particles) are supported on fibrous alumina-based oxides (alumina nanofibers) is flattened. Compared with the catalyst carrier made of aggregates of spherical alumina particles and spherical CZLY particles (Comparative Example 1) and the catalyst carrier made of aggregates of needle-shaped alumina particles and spherical CZLY particles (Comparative Example 2). It was found that the pore volume of the mesopores was large. It is presumed that this is because the network structure is formed by the fibrous alumina-based oxide in the exhaust gas purification catalyst carrier (Examples 1 to 3) of the present invention.
また、実施例１〜３で得られた焼成粉末を含有する排ガス浄化用触媒は、比較例１〜２で得られた焼成粉末を含有する排ガス浄化用触媒に比べて、粒子状酸化物の平均一次粒子径や貴金属粒子の結晶子径が小さいことがわかった。これは、本発明の排ガス浄化用触媒（実施例１〜３）においては、繊維状のアルミナ系酸化物（アルミナナノファイバー）が粒子状酸化物や貴金属粒子に対して拡散障壁として機能したことに加えて、メソ細孔の細孔容量が大きいことによって、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が抑制されたためと推察される。 Further, the exhaust gas purification catalyst containing the calcined powder obtained in Examples 1 to 2 has an average of particulate oxides as compared with the exhaust gas purification catalyst containing the calcined powder obtained in Comparative Examples 1 and 2. It was found that the primary particle size and the crystallite size of the noble metal particles were small. This is because in the exhaust gas purification catalyst of the present invention (Examples 1 to 3), the fibrous alumina-based oxide (alumina nanofiber) functioned as a diffusion barrier against particulate oxide and noble metal particles. In addition, it is presumed that the large pore volume of the mesopores suppressed the grain growth due to the catalysis of particulate oxides and noble metals at high temperatures.
さらに、実施例１〜３で得られた焼成粉末を含有する排ガス浄化用触媒は、高温に曝された場合であっても、比較例１〜２で得られた焼成粉末を含有する排ガス浄化用触媒に比べて、高い酸素吸放出速度（ＯＳＣ速度）を示すことがわかった。これは、本発明の排ガス浄化用触媒（実施例１〜３）においては、高温下における粒子状酸化物や貴金属のシンタリングによる粒成長が抑制されたことによって触媒活性の低下が抑制され、さらに、高温に曝された場合であっても、メソ細孔の大きな細孔容量が維持されたことによって高いガス拡散性が得られたためと推察される。 Further, the exhaust gas purification catalyst containing the calcined powder obtained in Examples 1 to 2 is for exhaust gas purification containing the calcined powder obtained in Comparative Examples 1 and 2 even when exposed to a high temperature. It was found that the oxygen absorption / release rate (OSC rate) was higher than that of the catalyst. This is because, in the exhaust gas purification catalyst of the present invention (Examples 1 to 3), the decrease in catalytic activity is suppressed by suppressing the grain growth due to the sintering of particulate oxides and noble metals at high temperatures, and further. It is presumed that high gas diffusivity was obtained by maintaining the large pore capacity of the mesopores even when exposed to high temperatures.
以上説明したように、本発明によれば、高温に曝された場合であっても優れた酸素吸放出速度（ＯＳＣ速度）を示す排ガス浄化用触媒を得ることが可能となる。 As described above, according to the present invention, it is possible to obtain an exhaust gas purification catalyst exhibiting an excellent oxygen absorption / release rate (OSC rate) even when exposed to a high temperature.
したがって、本発明の排ガス浄化用触媒は、自動車の内燃機関等から排出される有害物質を含むガスを浄化するための排ガス浄化用触媒、特に、高温環境下で長時間使用される排ガス浄化用触媒等として有用である。 Therefore, the exhaust gas purification catalyst of the present invention is an exhaust gas purification catalyst for purifying a gas containing harmful substances emitted from an internal combustion engine of an automobile, particularly an exhaust gas purification catalyst used for a long time in a high temperature environment. It is useful as such.
１：繊維状アルミナ系酸化物、２：粒子状酸化物、３：扁球状又は針状アルミナ、４：粒子状酸化物。 1: Fibrous alumina-based oxide, 2: Particulate oxide, 3: Spherical or acicular alumina, 4: Particulate oxide.
Claims (7)
細孔直径が３〜５０ｎｍのメソ細孔を有し、該メソ細孔の触媒担体１ｇ当たりの全細孔容量が０．３ｃｍ ３ ／ｇ以上である
ことを特徴とする排ガス浄化用触媒担体。 A fibrous alumina-based oxide having an average minor axis of 1 to 20 nm and an average aspect ratio of 10 or more, and a particulate oxide having an average primary particle diameter of 1 to 20 nm and an average aspect ratio of 3 or less and containing ceria . And, containing ,
Exhaust gas purification characterized by having mesopores having a pore diameter of 3 to 50 nm and having a total pore volume of 0.3 cm 3 / g or more per 1 g of the catalyst carrier of the mesopores. For catalyst carrier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017136455A JP6909402B2 (en) | 2017-07-12 | 2017-07-12 | A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017136455A JP6909402B2 (en) | 2017-07-12 | 2017-07-12 | A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2019018126A JP2019018126A (en) | 2019-02-07 |
| JP6909402B2 true JP6909402B2 (en) | 2021-07-28 |
Family
ID=65353777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2017136455A Active JP6909402B2 (en) | 2017-07-12 | 2017-07-12 | A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6909402B2 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69722596D1 (en) * | 1996-03-05 | 2003-07-10 | Goro Sato | ALUMINUM OXIDE SOL, METHOD FOR THE PRODUCTION THEREOF, METHOD FOR THE PRODUCTION OF AN ALUMINUM OXIDE PART USING THE SAME AND A CATALYST BASED ON IT FROM ITS ALUMINUM OXIDE |
| JP2000191321A (en) * | 1998-12-25 | 2000-07-11 | Catalysts & Chem Ind Co Ltd | Production of alumina |
| JP4715556B2 (en) * | 2006-03-01 | 2011-07-06 | 日産自動車株式会社 | Exhaust gas purification catalyst and method for producing the same |
| JP4817918B2 (en) * | 2006-03-24 | 2011-11-16 | 第一稀元素化学工業株式会社 | Exhaust gas purification catalyst, exhaust gas purification integrated structure type catalyst, and exhaust gas purification method |
| JP4881758B2 (en) * | 2006-04-28 | 2012-02-22 | 日産自動車株式会社 | Exhaust gas purification catalyst and method for producing the same |
-
2017
- 2017-07-12 JP JP2017136455A patent/JP6909402B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2019018126A (en) | 2019-02-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6595028B2 (en) | Method for producing exhaust gas purification catalyst | |
| CA2975394A1 (en) | Rhodium-containing catalysts for automotive emissions treatment | |
| EP3250320A1 (en) | Platinum group metal (pgm) catalysts for automotive emissions treatment | |
| JP5565569B2 (en) | Exhaust gas purification catalyst | |
| JP4998663B2 (en) | Composite metal oxide porous body | |
| JP2007301526A (en) | Catalyst for cleaning exhaust gas and its manufacturing method | |
| JP5859487B2 (en) | Exhaust gas purification catalyst carrier, exhaust gas purification catalyst using the same, and method for producing exhaust gas purification catalyst carrier | |
| JP3265534B2 (en) | Exhaust gas purification catalyst | |
| JP5703924B2 (en) | Columnar ceria catalyst | |
| JP5652271B2 (en) | Exhaust gas purification catalyst carrier, exhaust gas purification catalyst using the same, and method for producing exhaust gas purification catalyst carrier | |
| JP5887575B2 (en) | Co-catalyst material for purification of automobile exhaust gas and method for producing the same | |
| JP6325010B2 (en) | Alumina-based composite oxide and method for producing the same | |
| JP6532825B2 (en) | Exhaust gas purification catalyst | |
| JP4589032B2 (en) | Exhaust gas purification catalyst and oxygen storage material for the catalyst | |
| JP6909402B2 (en) | A catalyst carrier for exhaust gas purification, a catalyst for exhaust gas purification using the same, and a method for producing a catalyst carrier for exhaust gas purification. | |
| JP2016209862A (en) | Exhaust gas purification catalyst | |
| JP6050703B2 (en) | Exhaust gas purification catalyst | |
| JP2006181473A (en) | Catalyst for water-gas-shift reaction and its manufacturing method | |
| JP2007136420A (en) | Exhaust gas purification catalyst and method of fabricating the same | |
| JP5792683B2 (en) | Method for producing catalyst carrier for exhaust gas purification | |
| JP6625150B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
| JP2012066165A (en) | Catalyst for purifying automobile exhaust gas | |
| JP5402334B2 (en) | Exhaust gas purification catalyst | |
| JP6096818B2 (en) | Exhaust gas purification catalyst, method for producing the same, and exhaust gas purification method using the same | |
| JP2007203160A (en) | Catalyst support for purification of exhaust gas, catalyst for purification of exhaust gas using it and method of purifying exhaust gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20200529 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20210225 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20210317 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20210513 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20210603 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20210616 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6909402 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |