JP6245695B2 - Exhaust gas purification catalyst carrier and exhaust gas purification catalyst - Google Patents
Exhaust gas purification catalyst carrier and exhaust gas purification catalyst Download PDFInfo
- Publication number
- JP6245695B2 JP6245695B2 JP2013266289A JP2013266289A JP6245695B2 JP 6245695 B2 JP6245695 B2 JP 6245695B2 JP 2013266289 A JP2013266289 A JP 2013266289A JP 2013266289 A JP2013266289 A JP 2013266289A JP 6245695 B2 JP6245695 B2 JP 6245695B2
- Authority
- JP
- Japan
- Prior art keywords
- silica
- exhaust gas
- alumina
- catalyst
- dispersed
- 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 94
- 238000000746 purification Methods 0.000 title claims description 23
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 93
- 239000011148 porous material Substances 0.000 claims description 62
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 57
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 27
- 229910052751 metal Inorganic materials 0.000 claims description 25
- 239000002184 metal Substances 0.000 claims description 25
- 239000002245 particle Substances 0.000 claims description 9
- 239000011856 silicon-based particle Substances 0.000 claims description 6
- 238000000635 electron micrograph Methods 0.000 claims description 4
- 238000010191 image analysis Methods 0.000 claims description 4
- 239000007789 gas Substances 0.000 description 38
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 30
- 239000000377 silicon dioxide Substances 0.000 description 19
- 229930195733 hydrocarbon Natural products 0.000 description 18
- 150000002430 hydrocarbons Chemical class 0.000 description 18
- 238000010304 firing Methods 0.000 description 17
- 238000001035 drying Methods 0.000 description 16
- 230000002378 acidificating effect Effects 0.000 description 15
- 230000000052 comparative effect Effects 0.000 description 15
- 238000000034 method Methods 0.000 description 15
- 239000004215 Carbon black (E152) Substances 0.000 description 14
- 230000003197 catalytic effect Effects 0.000 description 13
- 230000000704 physical effect Effects 0.000 description 12
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 11
- 230000032683 aging Effects 0.000 description 10
- 229910052782 aluminium Inorganic materials 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 9
- 239000011888 foil Substances 0.000 description 9
- 239000000017 hydrogel Substances 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 230000010718 Oxidation Activity Effects 0.000 description 8
- 229910000510 noble metal Inorganic materials 0.000 description 8
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 7
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 238000005470 impregnation Methods 0.000 description 6
- 238000005259 measurement Methods 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 238000001179 sorption measurement Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 239000000499 gel Substances 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 229910052697 platinum Inorganic materials 0.000 description 5
- 238000002360 preparation method Methods 0.000 description 5
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 4
- 230000008602 contraction Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 229910052763 palladium Inorganic materials 0.000 description 4
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 3
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 239000004115 Sodium Silicate Substances 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 3
- 238000005549 size reduction Methods 0.000 description 3
- 229910052911 sodium silicate Inorganic materials 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- QPUYECUOLPXSFR-UHFFFAOYSA-N 1-methylnaphthalene Chemical compound C1=CC=C2C(C)=CC=CC2=C1 QPUYECUOLPXSFR-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- -1 Platinum group metals Chemical class 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- DIOQZVSQGTUSAI-UHFFFAOYSA-N decane Chemical compound CCCCCCCCCC DIOQZVSQGTUSAI-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001879 gelation Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 238000010335 hydrothermal treatment Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 235000019353 potassium silicate Nutrition 0.000 description 2
- 229910052703 rhodium Inorganic materials 0.000 description 2
- 239000010948 rhodium Substances 0.000 description 2
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- JQMFQLVAJGZSQS-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]-N-(2-oxo-3H-1,3-benzoxazol-6-yl)acetamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)CC(=O)NC1=CC2=C(NC(O2)=O)C=C1 JQMFQLVAJGZSQS-UHFFFAOYSA-N 0.000 description 1
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 238000004438 BET method Methods 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004111 Potassium silicate Substances 0.000 description 1
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 1
- 238000003917 TEM image Methods 0.000 description 1
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- AFTDTIZUABOECB-UHFFFAOYSA-N [Co].[Mo] Chemical compound [Co].[Mo] AFTDTIZUABOECB-UHFFFAOYSA-N 0.000 description 1
- QZYDAIMOJUSSFT-UHFFFAOYSA-N [Co].[Ni].[Mo] Chemical compound [Co].[Ni].[Mo] QZYDAIMOJUSSFT-UHFFFAOYSA-N 0.000 description 1
- YCOASTWZYJGKEK-UHFFFAOYSA-N [Co].[Ni].[W] Chemical compound [Co].[Ni].[W] YCOASTWZYJGKEK-UHFFFAOYSA-N 0.000 description 1
- RAFNAMHEPCFDRC-UHFFFAOYSA-N [W].[Mo].[Co].[Ni] Chemical compound [W].[Mo].[Co].[Ni] RAFNAMHEPCFDRC-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 229910052910 alkali metal silicate Inorganic materials 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 1
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000000975 co-precipitation Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000003795 desorption Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000002923 metal particle Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- DDTIGTPWGISMKL-UHFFFAOYSA-N molybdenum nickel Chemical compound [Ni].[Mo] DDTIGTPWGISMKL-UHFFFAOYSA-N 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- MOWMLACGTDMJRV-UHFFFAOYSA-N nickel tungsten Chemical compound [Ni].[W] MOWMLACGTDMJRV-UHFFFAOYSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 229910052913 potassium silicate Inorganic materials 0.000 description 1
- NNHHDJVEYQHLHG-UHFFFAOYSA-N potassium silicate Chemical compound [K+].[K+].[O-][Si]([O-])=O NNHHDJVEYQHLHG-UHFFFAOYSA-N 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052707 ruthenium Inorganic materials 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Description
本発明は、シリカ分散アルミナからなる排ガス浄化用触媒担体及び該触媒担体に白金族金属を担持した排ガス浄化用触媒に関する。 The present invention relates to an exhaust gas purification catalyst carrier made of silica-dispersed alumina and an exhaust gas purification catalyst in which a platinum group metal is supported on the catalyst carrier.
白金、パラジウム、ロジウムに代表される白金族金属は、排ガス浄化用触媒としての機能を有しており、このような白金族金属を多孔質担体に担持させたものは、例えば自動車の排ガス中に含まれる炭化水素（ＨＣ）、一酸化炭素（ＣＯ）、窒素酸化物（ＮＯｘ）を浄化するための触媒として使用されている（特許文献１参照）。 Platinum group metals typified by platinum, palladium, and rhodium have a function as exhaust gas purifying catalysts, and those in which such a platinum group metal is supported on a porous carrier are, for example, in automobile exhaust gas. It is used as a catalyst for purifying contained hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx) (see Patent Document 1).
ところで、上記のような白金族金属は貴金属であり、非常に高価であるため、その触媒機能が効率よく発揮されるように多孔質担体（触媒担体）に保持しなければならない。従って、触媒担体として好適に使用される多孔質担体についても種々の提案がなされている。 By the way, the platinum group metal as described above is a noble metal and is very expensive. Therefore, the platinum group metal must be held on a porous carrier (catalyst carrier) so that its catalytic function is efficiently exhibited. Accordingly, various proposals have been made for porous carriers that are suitably used as catalyst carriers.
例えば、特許文献１には、アルミナ、セリア、ジルコニア、チタニア、シリカ、ゼオライト及びメソポーラスシリカからなる群より選択された少なくとも１種を、上記白金族金属を担持させる触媒担体として用いることが提案されている。
また、特許文献２には、ＳｉＯ２とＺｒＯ２との複合酸化物を焼結したものを排ガス浄化用触媒の触媒担体として用いることが提案されている。
さらに、特許文献３には、規則的周期構造を有する均一なメソ孔を備え且つ一定割合でＳｉ−Ｏ−Ｚｒ結合を有するメソポーラスシリカを触媒担体として用いることが提案されている。
For example, Patent Document 1 proposes that at least one selected from the group consisting of alumina, ceria, zirconia, titania, silica, zeolite, and mesoporous silica is used as a catalyst carrier for supporting the platinum group metal. Yes.
Patent Document 2 proposes that a composite oxide of SiO 2 and ZrO 2 is used as a catalyst carrier for an exhaust gas purification catalyst.
Further, Patent Document 3 proposes to use mesoporous silica having uniform mesopores having a regular periodic structure and having Si—O—Zr bonds at a certain ratio as a catalyst carrier.
上述した種々の触媒担体の中では、規則的周期構造を有する均一なメソ孔を備えたメソポーラスシリカは、白金族金属の粒子を凝集することなく均一に分散して保持することができるため、特に注目されている。 Among the various catalyst supports described above, mesoporous silica having uniform mesopores having a regular periodic structure can be uniformly dispersed and held without agglomerating the platinum group metal particles. Attention has been paid.
しかしながら、この種のメソポーラスシリカは、均一なメソ孔を形成するために、高価な界面活性剤を使用しなければならず、しかも、この界面活性剤は熱分解により除去されてしまうため、再利用することもできないという問題がある。即ち、このようなメソポーラスシリカは、極めて高価なものであり、これに白金族金属を担持させた排ガス浄化用触媒は、著しく高価なものとなってしまい、その実用化を妨げているのが難点である。
さらに、従来公知の触媒は、一般に耐熱耐久性が低く、例えば７５０℃、５０時間のエージングを行った後では、３５０℃でのＮＯ酸化率が大きく低下する傾向がある。
However, this type of mesoporous silica requires the use of an expensive surfactant in order to form uniform mesopores, and this surfactant is removed by thermal decomposition. There is a problem that can not be done. That is, such mesoporous silica is extremely expensive, and an exhaust gas purifying catalyst in which a platinum group metal is supported is extremely expensive, which hinders its practical application. It is.
Furthermore, conventionally known catalysts generally have low heat durability, and for example, after aging at 750 ° C. for 50 hours, the NO oxidation rate at 350 ° C. tends to be greatly reduced.
また、特許文献４には、白金族金属等の貴金属触媒の担持に適した細孔を有しているとともに、極めて安価に製造し得る新規な多孔質体として、非晶質シリカジルコニウム複合体からなる排ガス浄化用触媒担体が、本発明者等により提案されている。かかる担体は、極めて安価に製造できるばかりか、これに貴金属触媒が担持された排ガス浄化用触媒は、耐熱耐久性が改善されている。 Patent Document 4 discloses an amorphous silica-zirconium composite as a novel porous body that has pores suitable for supporting a noble metal catalyst such as a platinum group metal and can be manufactured at a very low cost. The present inventors have proposed an exhaust gas purifying catalyst carrier. Such a carrier can be produced at a very low cost, and the heat-resistant durability of the exhaust gas-purifying catalyst in which the noble metal catalyst is supported is improved.
さらに、本発明者等は、先に、Ｓｉ／（Ｓｉ＋Ａｌ）が１．０〜１０．０ｍｏｌ％の範囲にあり、Ｓｉ粒子の面積占有率が７０％以上であるシリカ分散アルミナからなる排ガス浄化用触媒担体を提案した（特開２０１３−１８８７０３）。かかる担体は、極めて安価に製造できるばかりか、これに貴金属触媒を担持した排ガス浄化用触媒は、良好な耐熱耐久性を示すと同時に、その触媒能（ＨＣ、ＣＯ、ＮＯｘ等に対する浄化作用）も、前述した特許文献１〜４と同等である。 Furthermore, the present inventors have previously described for exhaust gas purification comprising silica-dispersed alumina in which Si / (Si + Al) is in the range of 1.0 to 10.0 mol% and the area occupancy of the Si particles is 70% or more. A catalyst carrier was proposed (Japanese Patent Laid-Open No. 2013-188703). Such a carrier can be manufactured at an extremely low cost, and an exhaust gas purifying catalyst carrying a noble metal catalyst on the carrier exhibits good heat resistance and durability, and also has a catalytic ability (purifying action against HC, CO, NOx, etc.). , Which is equivalent to Patent Documents 1 to 4 described above.
本発明者等は、極めて安価であり、貴金属触媒の担持に適した排ガス浄化用触媒担体について研究を重ねた結果、上記先願のようにシリカ粒子がアルミナ粒子に分散されたシリカ分散アルミナでは、ある程度以上の細孔容積を確保することが良好な排ガス浄化能を確保するために必要であり、このために、一定量以上のシリカ粒子を分散させるのであるが、このＳｉ含有量が増大するにしたがい平均細孔直径が小さくなる傾向にあるという知見を得ると同時に、排ガス浄化作用をさらに向上させるためには、この細孔が大きい方が排ガス浄化特性が高いこと、及びシリカ分散アルミナの製造条件によっては、Ｓｉ含有量を増大させながら（細孔容積を大きくする）、細孔径の低下を緩和できるという知見を見出し、本発明を完成させるに至った。 The inventors of the present invention have conducted research on an exhaust gas purification catalyst carrier that is extremely inexpensive and suitable for supporting a noble metal catalyst, and as a result, in silica-dispersed alumina in which silica particles are dispersed in alumina particles as in the previous application, It is necessary to ensure a pore volume of a certain level or more in order to ensure a good exhaust gas purification ability. For this reason, silica particles of a certain amount or more are dispersed, but this Si content increases. Accordingly, in order to obtain the knowledge that the average pore diameter tends to be smaller and at the same time to further improve the exhaust gas purification action, the larger the pores, the higher the exhaust gas purification characteristics, and the conditions for producing silica-dispersed alumina. In some cases, the inventors have found that the decrease in pore diameter can be alleviated while increasing the Si content (increasing the pore volume), thereby completing the present invention. .
即ち、本発明の目的は、Ｓｉ含有量を増大させて細孔容積を大きくしながら細孔の小径化を抑制し、より優れた触媒浄化作用を示すことが可能なシリカ分散アルミナからなる排ガス浄化用触媒担体を提供することにある。
本発明のさらに他の目的は、上記の触媒担体に白金族金属を担持して得られ、耐熱耐久性に優れた排ガス浄化用触媒を提供することにある。
That is, an object of the present invention is to purify exhaust gas composed of silica-dispersed alumina capable of suppressing pore size reduction while increasing the Si content to increase the pore volume and exhibit a more excellent catalyst purification action. It is to provide a catalyst support for use.
Still another object of the present invention is to provide an exhaust gas purifying catalyst which is obtained by supporting a platinum group metal on the catalyst carrier and has excellent heat resistance.
本発明によれば、アルミナ粒子中にシリカ粒子が分散したシリカ分散アルミナからなる排ガス浄化用触媒担体であって、前記シリカ分散アルミナは、１００×Ｓｉ／（Ｓｉ＋Ａｌ）で表されるＳｉ含有量が１．０〜１０．０ｍｏｌ％の範囲内にあり、平均細孔直径が４．０ｎｍ以上であり、前記Ｓｉ含有量をＳ（ｍｏｌ％）、前記平均細孔直径をＭＤ（ｎｍ）としたとき、Ｓ×（ＭＤ／２）４の値が３４０以上であり、倍率２００，０００倍の電子顕微鏡写真の画像解析で算出される面積９０，０００ｎｍ２でのＳｉ粒子の面積占有率が７０％以上として観察されることを特徴とする排ガス浄化用触媒担体が提供される。 According to the present invention, there is provided an exhaust gas purifying catalyst carrier comprising silica-dispersed alumina in which silica particles are dispersed in alumina particles, wherein the silica-dispersed alumina has a Si content represented by 100 × Si / (Si + Al). When the average pore diameter is 4.0 nm or more in the range of 1.0 to 10.0 mol%, the Si content is S (mol%), and the average pore diameter is MD (nm) , S × (MD / 2) 4 has a value of 340 or more, and the area occupancy ratio of Si particles at an area of 90,000 nm 2 calculated by image analysis of an electron micrograph at a magnification of 200,000 times is 70% or more. The catalyst carrier for exhaust gas purification characterized by the above is provided.
本発明の排ガス浄化用触媒担体は、
（１） 細孔容積が０．２５〜０．７５ｃｍ３／ｇであるという性質を有している。
The exhaust gas purifying catalyst carrier of the present invention comprises:
(1) It has the property that the pore volume is 0.25 to 0.75 cm 3 / g.
本発明によれば、また、上記触媒担体に白金族金属を担持してなる排ガス浄化用触媒が提供される。 According to the present invention, there is also provided an exhaust gas purifying catalyst comprising a platinum group metal supported on the catalyst carrier.
本発明の排ガス浄化用触媒担体は、例えば排ガス浄化用触媒として好適に機能する白金族金属触媒を効率よく担持させることができる。即ち、この触媒担体は、シリカ分散アルミナからなるものであり、アルミナを主成分（マトリックス）とし、特に少量のシリカ粒子のほとんどが、粒径が１０ｎｍ以下の微細なシリカの形態で分散しており、このため、１００×Ｓｉ／（Ｓｉ＋Ａｌ）で表されるＳｉ含有量が１．０〜１０．０ｍｏｌ％の範囲内にあり、平均細孔直径（窒素吸着法により測定）が４．０ｎｍ以上（特に、５．０〜１０．０ｎｍ）と大きく、電子顕微鏡により観察して、Ｓｉ粒子の面積占有率が７０％以上である。また、細孔容積が０．２５〜０．７５ｃｍ３／ｇと大きい。
このような触媒担体では、白金等の白金族触媒を安定に担持することができ、しかも、この触媒担体は、高価な界面活性剤などを使用することなく、極めて安価に製造することができる。
The exhaust gas purifying catalyst carrier of the present invention can efficiently support, for example, a platinum group metal catalyst that functions suitably as an exhaust gas purifying catalyst. That is, this catalyst carrier is made of silica-dispersed alumina, and alumina is the main component (matrix), and most of the small amount of silica particles are dispersed in the form of fine silica having a particle size of 10 nm or less. Therefore, the Si content represented by 100 × Si / (Si + Al) is in the range of 1.0 to 10.0 mol%, and the average pore diameter (measured by the nitrogen adsorption method) is 4.0 nm or more ( In particular, the area occupancy of Si particles is 70% or more as observed with an electron microscope. Further, the pore volume is as large as 0.25 to 0.75 cm 3 / g.
With such a catalyst carrier, a platinum group catalyst such as platinum can be stably supported, and this catalyst carrier can be produced at an extremely low cost without using an expensive surfactant or the like.
また、本発明の触媒担体を構成するシリカ分散アルミナは、Ｓｉ含有量の点では、本発明者等が特開２０１３−１８８７０３で提案したシリカ分散アルミナと同じであるが、Ｓｉ含有量の増大に伴う細孔の小径化が抑制されており、前記Ｓｉ含有量をＳ（ｍｏｌ％）、前記平均細孔直径をＭＤ（ｎｍ）としたとき、関係式Ｓ×（ＭＤ／２）４の値が３２５より大きいものとなっている。即ち、本発明者等が特開２０１３−１８８７０３で提案したシリカ分散アルミナでは、前記関係式（Ｓ×（ＭＤ／２）４）は、上記範囲よりも小さいものとなっている。この結果、後述する実施例で示されるように、これに貴金属触媒を担持させた排ガス浄化用触媒では、炭化水素（ＨＣ）や窒素酸化物（ＮＯｘ）に対する浄化作用がさらに向上している。 Further, the silica-dispersed alumina constituting the catalyst carrier of the present invention is the same as the silica-dispersed alumina proposed by the present inventors in JP2013-188703 in terms of Si content. The accompanying pore size reduction is suppressed, and when the Si content is S (mol%) and the average pore diameter is MD (nm), the value of the relational expression S × (MD / 2) 4 is It is larger than 325. That is, in the silica-dispersed alumina proposed by the present inventors in JP2013-188703, the relational expression (S × (MD / 2) 4 ) is smaller than the above range. As a result, as shown in the examples described later, in the exhaust gas purification catalyst in which the noble metal catalyst is supported, the purification action against hydrocarbons (HC) and nitrogen oxides (NOx) is further improved.
さらに、上記の触媒担体に白金族金属を担持した本発明の排ガス浄化用触媒は、耐熱耐久性に優れており、例えば３５０℃でのＮＯ酸化率が高いばかりか、７５０℃のエージングを行った後においてもＮＯ酸化率はほとんど低下せず、さらに、９００℃でエージングを行った場合にもＮＯ酸化率の低下が抑制される。このことから理解されるように、本発明の排ガス浄化用触媒は、耐熱耐久性にも優れており、長期間にわたって、触媒活性が安定に維持されている。 Furthermore, the exhaust gas purifying catalyst of the present invention in which a platinum group metal is supported on the above catalyst carrier is excellent in heat resistance durability, for example, not only has a high NO oxidation rate at 350 ° C. but also aged at 750 ° C. Even later, the NO oxidation rate hardly decreases. Further, even when aging is performed at 900 ° C., the reduction of the NO oxidation rate is suppressed. As understood from this, the exhaust gas purifying catalyst of the present invention is excellent in heat resistance and durability, and its catalytic activity is stably maintained over a long period of time.
＜シリカ分散アルミナ＞
排ガス浄化用触媒として使用されるシリカ分散アルミナは、アルミナ中に微量の微細なシリカが分散された構造を有しており、１００×Ｓｉ／（Ｓｉ＋Ａｌ）で表されるＳｉ含有量が１．０〜１０．０ｍｏｌ％、特に１．５〜８．０ｍｏｌ％の範囲内にあると同時に、図１の電子顕微鏡写真から理解されるように、例えば倍率２００，０００倍の電子顕微鏡写真の画像解析で算出される面積９０，０００ｎｍ２でのシリカ粒子の面積占有率（Ｓｉ粒子の面積占有率という）は、常に７０％以上であり、このことから、シリカ粒子が偏在しておらず、均一に分散されていることが判る。
<Silica-dispersed alumina>
Silica-dispersed alumina used as an exhaust gas purification catalyst has a structure in which a minute amount of fine silica is dispersed in alumina, and the Si content represented by 100 × Si / (Si + Al) is 1.0. As shown in the electron micrograph of FIG. 1, at the same time as being in the range of ˜10.0 mol%, particularly 1.5 to 8.0 mol%, for example, in the image analysis of an electron micrograph at a magnification of 200,000 times The area occupancy of the silica particles in the calculated area of 90,000 nm 2 (referred to as the area occupancy of the Si particles) is always 70% or more. Therefore, the silica particles are not unevenly distributed and are uniformly dispersed. It can be seen that
即ち、上記のようなシリカ分散アルミナに白金族触媒を担持させて排ガス浄化用触媒として使用するときには、その触媒活性の耐熱耐久性が極めて高く、７５０℃でエージング処理を行った場合においても、エージング処理前と同等の触媒活性を示し、例えば優れたＮＯ酸化活性がエージング処理によって失われることはない。 That is, when a platinum group catalyst is supported on the silica-dispersed alumina as described above and used as an exhaust gas purification catalyst, the heat resistance and durability of the catalyst activity is extremely high, and even when aging is performed at 750 ° C. The catalyst activity is the same as that before the treatment, and for example, excellent NO oxidation activity is not lost by the aging treatment.
本発明において、上記のような優れた耐熱耐久性が得られることは、実験的に確認されてはいるが、その理由については明確に解明されていない。しかるに、本発明者等は次のように推定している。
即ち、極めて微細なシリカが微量分散されているシリカ分散アルミナでは、基本的にアルミナの細孔にＰｔ等の触媒が担持されるが、これを高温に加熱したとき、アルミナの骨格内や粒子間隙に存在する微細なシリカが細孔の熱収縮を抑制するように作用し、この結果として、細孔内に触媒が安定に保持され、高温での熱処理によっても触媒活性が損なわれず、安定に維持されるものと考えられるのである。
In the present invention, it has been experimentally confirmed that excellent heat resistance as described above can be obtained, but the reason has not been clearly clarified. However, the present inventors estimate as follows.
That is, in silica-dispersed alumina in which a very small amount of fine silica is dispersed, a catalyst such as Pt is basically supported in the pores of the alumina. The fine silica present in the pores acts to suppress thermal contraction of the pores. As a result, the catalyst is stably held in the pores, and the catalytic activity is not impaired even by heat treatment at high temperature, and it is maintained stably. It is considered to be done.
例えば、Ｓｉ含有量（ｍｏｌ％）が前述した範囲よりも大きい場合には、分散されているシリカ量が多く、この結果、細孔内への触媒担持に支障を来たし、触媒活性そのものが低下してしまう。また、Ｓｉ含有量（ｍｏｌ％）が前述した範囲よりも小さいときには、分散されているシリカ量が少ないため、アルミナ細孔の熱収縮を十分に抑制することができず、触媒活性の耐熱耐久性が不満足なものとなってしまう。 For example, when the Si content (mol%) is larger than the above-mentioned range, the amount of dispersed silica is large, resulting in hindering catalyst loading in the pores and reducing the catalytic activity itself. End up. Further, when the Si content (mol%) is smaller than the above-mentioned range, the amount of silica dispersed is small, so that the heat shrinkage of the alumina pores cannot be sufficiently suppressed, and the heat resistance and durability of the catalytic activity. Becomes unsatisfactory.
さらに、Ｓｉ粒子の面積占有率が前述した範囲より低い場合には、細孔の熱収縮の抑制に寄与する微細シリカ粒子の量が少なくなるばかりか、粗大な粒子の存在により、微細シリカ粒子が偏在するようになり、結局、粒径の大きな粒子が多く存在することとなり、アルミナ細孔の熱収縮を十分に抑制することができず、触媒活性の耐熱耐久性が不満足なものとなってしまう。 Furthermore, when the area occupancy of the Si particles is lower than the above-described range, not only the amount of fine silica particles contributing to the suppression of thermal contraction of the pores is reduced, but also the presence of coarse particles causes the fine silica particles to be reduced. As a result, there will be a large number of particles having a large particle size, and the thermal contraction of the alumina pores cannot be sufficiently suppressed, and the heat resistance and durability of the catalytic activity will be unsatisfactory. .
尚、シリカ分散アルミナ中のアルミナは、特に制限されるものではないが、γ、θ、δ、η、κ等の結晶構造を有するもの、特にγ−アルミナが好適である。 The alumina in the silica-dispersed alumina is not particularly limited, but those having a crystal structure such as γ, θ, δ, η, and κ, particularly γ-alumina are suitable.
さらに、本発明におけるシリカ分散アルミナにおいては、Ｓｉ含有量が前述した範囲にあることに関連して、その平均細孔直径が４．０ｎｍ以上、特に５．０〜１０．０ｎｍと大きな値を示す。これに加えて細孔容積も０．２５〜０．７５ｃｍ３／ｇと大きな値を示す。
即ち、シリカ分散アルミナでは、一般に、Ｓｉ含有量の増大と共に細孔が小径化される傾向にある。これはシリカ分散アルミナを製造する際の熱履歴に伴い、シリカ粒子の熱収縮が大きく反映されていくためであると思われる。しかるに、本発明におけるシリカ分散アルミナでは、Ｓｉ含有量の増大に伴う細孔の小径化が抑制されており、このため、上記のような大きな平均細孔直径を有しているわけである。また、細孔の小径化が抑制されていることは、後述する実施例にも示されているように、前記Ｓｉ含有量をＳ（ｍｏｌ％）、前記平均細孔直径をＭＤ（ｎｍ）としたとき、このシリカ分散アルミナにおける両者関係式Ｓ×（ＭＤ／２）４が３２５より大きく、最も好ましくは５９３より大きな値を示すことに現れている。例えば、Ｓｉ含有量の増大と共に細孔が小径化されている先願のシリカ分散アルミナ（表１の比較例１）では、その値は、本発明に比して、小さい値を示している。
Further, in the silica-dispersed alumina in the present invention, the average pore diameter is 4.0 nm or more, particularly a large value of 5.0 to 10.0 nm in relation to the Si content being in the above-mentioned range. . In addition to this, the pore volume also shows a large value of 0.25 to 0.75 cm 3 / g.
That is, in silica-dispersed alumina, in general, pores tend to be reduced in size as the Si content increases. This seems to be because the thermal shrinkage of the silica particles is largely reflected along with the thermal history when producing the silica-dispersed alumina. However, in the silica-dispersed alumina in the present invention, the reduction in the pore size due to the increase in the Si content is suppressed, and thus the large average pore diameter is as described above. In addition, the fact that the pore size reduction is suppressed, as shown in Examples described later, the Si content is S (mol%) and the average pore diameter is MD (nm). In this case, the relational expression S × (MD / 2) 4 in the silica-dispersed alumina is larger than 325, most preferably larger than 593. For example, in the silica-dispersed alumina (Comparative Example 1 in Table 1) of the prior application in which the pores are reduced in size as the Si content is increased, the value is smaller than that of the present invention.
このため、本発明で排ガス浄化用触媒の担体として用いるシリカ分散アルミナは、Ｓｉ含有量が従来公知のシリカ分散アルミナと同じであったとしても、その平均細孔直径は大きい。即ち、このような大きな平均細孔直径を有する細孔が多く形成されていることに関連して、かかるシリカ分散アルミナを触媒担体として使用し、この触媒担体に貴金属触媒を担持させた排ガス浄化用触媒は、炭化水素（ＨＣ）や窒素酸化物（ＮＯｘ）に対する浄化作用は、一層高められている。
このことから、本発明におけるシリカ分散アルミナは、炭化水素（ＨＣ）や窒素酸化物（ＮＯｘ）の浄化にマッチしたサイズの細孔を多く含んでいるものと認識される。
For this reason, the silica-dispersed alumina used as the carrier for the exhaust gas purifying catalyst in the present invention has a large average pore diameter even if the Si content is the same as that of conventionally known silica-dispersed alumina. That is, in connection with the fact that many pores having such a large average pore diameter are formed, such silica-dispersed alumina is used as a catalyst carrier, and this catalyst carrier is used for exhaust gas purification in which a noble metal catalyst is supported. The catalyst has a further enhanced purification effect on hydrocarbons (HC) and nitrogen oxides (NOx).
From this, it is recognized that the silica-dispersed alumina in the present invention contains many pores having a size matching the purification of hydrocarbons (HC) and nitrogen oxides (NOx).
＜シリカ分散アルミナの製造＞
本発明のシリカ分散アルミナは、前述したように、極めて微細であり且つ微量のシリカ粒子が偏在することなく均一に分散しているという分散構造を有していると同時に、Ｓｉ含有量の増大に伴う細孔の小径化が抑制されているという特有の性質を有しており、従って、単に微量の微細シリカをアルミナに混合するという手段によって得ることはできず、アルミナヒドロゲルからアルミナを製造する過程で微細シリカ（シリカゾル）を介在させておくと同時に、乾燥や焼成の熱処理を水分の存在下で行うという手段を採用することが必要である。
<Manufacture of silica-dispersed alumina>
As described above, the silica-dispersed alumina of the present invention is extremely fine and has a dispersion structure in which a minute amount of silica particles are uniformly dispersed without being unevenly distributed, while at the same time increasing the Si content. The process of producing alumina from an alumina hydrogel is not possible by simply mixing a minute amount of fine silica with alumina. In addition, it is necessary to adopt a means in which fine silica (silica sol) is interposed, and at the same time, heat treatment for drying and baking is performed in the presence of moisture.
具体的には、アルミナ源として硫酸アルミニウム溶液、シリカ源としてケイ酸の酸性ゾルを使用し、両者の混合液を原料とする。ゲル化、水洗、乾燥及び焼成の工程を経て、シリカ分散アルミナを製造するのであるが、特に乾燥や焼成の何れか、好ましくは焼成、最も好ましくは、乾燥及び焼成を水分の存在下で行うことが必要である。 Specifically, an aluminum sulfate solution is used as the alumina source, an acidic sol of silicic acid is used as the silica source, and a mixture of the two is used as a raw material. Silica-dispersed alumina is produced through steps of gelation, washing with water, drying and firing, and in particular, either drying or firing, preferably firing, most preferably drying and firing is performed in the presence of moisture. is necessary.
上記の方法で用いるケイ酸の酸性ゾルの調整には、工業製品としてＪＩＳに規格されている水ガラスのケイ酸ソーダやケイ酸カリが使用される。 For adjusting the acidic sol of silicic acid used in the above method, water glass sodium silicate or potassium silicate standardized by JIS as an industrial product is used.
また、この酸性ゾルは、酸性白土等の粘土質原料より回収した易反応性のシリカにアルカリ金属の水酸化物溶液を反応させてケイ酸アルカリを調製し、このケイ酸アルカリに塩酸や硫酸等の鉱酸を添加することによって製造することもできる。
例えば、ＳｉＯ２分を２１〜２３質量％含むケイ酸ソーダ水溶液と、４２〜４５質量％の濃度の硫酸水溶液を、容積比で約４：１になる量で連続的に高速混合してｐＨが１．６〜２．２の範囲になるように調整することにより、本発明で用いる酸性ゾルを得ることができる。
In addition, this acidic sol is prepared by reacting an alkali metal hydroxide solution with easily reactive silica recovered from clayey raw materials such as acidic clay, and preparing alkali silicate. It can also be produced by adding a mineral acid.
For example, a sodium silicate aqueous solution containing 21 to 23% by mass of SiO 2 and a sulfuric acid aqueous solution having a concentration of 42 to 45% by mass are continuously mixed at a high speed so as to have a volume ratio of about 4: 1. By adjusting so that it may become the range of 1.6-2.2, the acidic sol used by this invention can be obtained.
上記のケイ酸の酸性ゾルをアルミナ源の硫酸アルミニウム溶液に加えて原料液を調製するが、ケイ酸の酸性ゾルは、Ｓｉ含有量、即ち、１００×Ｓｉ／（Ｓｉ＋Ａｌ）のｍｏｌ比が前述した範囲（１．０〜１０．０ｍｏｌ％、特に１．５〜８．０ｍｏｌ％）の範囲内となるような量で使用される。 Preparing a raw material liquid acidic sol of the silicate in addition to aluminum sulfate solution of an alumina source, but acidic sol silicate, Si content, namely, mol ratio of 100 × Si / (Si + Al ) is above It is used in such an amount that it falls within the range (1.0 to 10.0 mol%, particularly 1.5 to 8.0 mol%).
上記の原料液を用いてのゲル化は、該液を４５．０〜８０．０℃の温度に加熱したアルカリ溶液（例えば苛性ソーダや水酸化アンモニウムなど）に混合することにより行われ、ゲル形成後、水洗を行い、これにより、シリカ粒子が分散固定されたアルミナヒドロゲルが得られる。 The gelation using the above raw material liquid is performed by mixing the liquid with an alkaline solution (for example, caustic soda or ammonium hydroxide) heated to a temperature of 45.0 to 80.0 ° C. After the gel is formed. By washing with water, an alumina hydrogel in which silica particles are dispersed and fixed is obtained.
上記で得られたアルミナヒドロゲルを乾燥し、得られた空隙の多いキセロゲルを焼成することにより、シリカ分散アルミナが得られるが、先に述べたように、本発明では、乾燥及び焼成の何れかを水分の存在下で行うことが必要である。即ち、理論的に解明されているわけではないが、熱履歴に際しては水分を介在させることにより、粒子、特にシリカ粒子の熱収縮が抑制され、Ｓｉ含有量の増大に伴う細孔の小径化が抑制されるものと思われる。 Silica-dispersed alumina is obtained by drying the alumina hydrogel obtained above and firing the resulting xerogel with many voids. As described above, in the present invention, either drying or firing is performed. It is necessary to carry out in the presence of moisture. That is, although not theoretically clarified, the thermal contraction of particles, particularly silica particles, is suppressed by interposing moisture in the thermal history, and the pore diameter is reduced as the Si content increases. It seems to be suppressed.
従って、乾燥は、所謂スチーム乾燥により行う。例えば６０℃以上、特に１００〜２００℃の蒸気を吹き付けることや乾燥機内の排気を抑えヒドロゲルからの水分を長時間滞留させながら乾燥を行う。 Therefore, drying is performed by so-called steam drying. For example, drying is performed while spraying steam at 60 ° C. or higher, particularly 100 to 200 ° C., or suppressing exhaust in the dryer and retaining moisture from the hydrogel for a long time.
また、焼成は、スチーム焼成により行う。このスチーム焼成は、キセロゲル自体から発生する水分を長時間滞留させながら焼成することができる容器で所定の焼成温度に加熱することにより行われる。
焼成温度は、一般に６００〜６４０℃程度である。この温度がα−アルミナ化するような高温だと、細孔収縮が大きく、触媒の担持に不適当となるおそれがある。また、温度が低すぎると、γ―アルミナ化しないおそれがある。
Moreover, baking is performed by steam baking. This steam firing is performed by heating to a predetermined firing temperature in a container that can be fired while retaining moisture generated from the xerogel itself for a long time.
The firing temperature is generally about 600 to 640 ° C. When this temperature is high enough to cause α-alumina, the pore shrinkage is large, which may be inappropriate for supporting the catalyst. If the temperature is too low, γ-alumina may not be formed.
尚、本発明においては、乾燥及び焼成の何れかを、上記のような水分存在下で行うことにより、目的とするシリカ分散アルミナを得ることができるが、好ましくは焼成をスチーム焼成とすることが好ましく、最も好ましくはスチーム乾燥とスチーム焼成との両方を行うのがよい。即ち、このような手段を採用することにより、より有効に粒子（特にシリカ粒子）の収縮が抑制され、Ｓｉ含有量の増大に伴う細孔の小径化が確実に回避され、例えば前述したＳ×（ＭＤ／２）４の値をより大きな値とすることができる。 In the present invention, the desired silica-dispersed alumina can be obtained by performing either drying or firing in the presence of moisture as described above, but preferably the firing is steam firing. Preferably, most preferably, both steam drying and steam baking are performed. That is, by adopting such means, the shrinkage of the particles (particularly silica particles) is more effectively suppressed, and the reduction in the diameter of the pores accompanying the increase in the Si content is surely avoided. (MD / 2) The value of 4 can be set to a larger value.
このようにして得られたシリカ分散アルミナは多孔質であり、内部に微量の微細シリカ粒子が均一に分散した構造を有しており、これにより、高温での熱処理による細孔の収縮が抑制され、さらにはＳｉ含有量の増大に伴う細孔の小径化も有効に抑制されており、触媒担体として優れた特性を示すことになる。 The silica-dispersed alumina thus obtained is porous and has a structure in which a minute amount of fine silica particles are uniformly dispersed therein, thereby suppressing pore shrinkage due to heat treatment at high temperature. In addition, the reduction of the pore diameter due to the increase in the Si content is effectively suppressed, and excellent characteristics as a catalyst carrier are exhibited.
かかるシリカ分散アルミナゲルは、キセロゲルの焼成により得られるものであることに関連して比較的大きな比表面積を有しており、一般に、ＢＥＴ比表面積が１５０〜４５０ｍ２／ｇ、好ましくは２００〜４００ｍ２／ｇの範囲にある。 Such a silica-dispersed alumina gel has a relatively large specific surface area in relation to being obtained by baking xerogel, and generally has a BET specific surface area of 150 to 450 m 2 / g, preferably 200 to 400 m. It is in the range of 2 / g.
＜触媒＞
上記のような特性を有するシリカ分散シリカゲルは、極めて安価であり、例えば押出成形、造粒成形等の公知の方法によって、円筒状、粒状、錠剤等の種々の形態に成形し、これに触媒を担持させて触媒としての使用に供される。特に触媒活性の耐熱耐久性に優れていることから、白金族金属を担持させた排ガス浄化用触媒として極めて好適であり、炭化水素の分解、ＮＯｘ及びカーボンの酸化等を促進させ、自動車等の排ガスをクリーンに浄化することができる。
<Catalyst>
Silica-dispersed silica gel having the above characteristics is extremely inexpensive, and is formed into various shapes such as cylindrical, granular, and tablet by a known method such as extrusion molding and granulation molding, and a catalyst is applied to this. The catalyst is used for use as a catalyst. In particular, since it has excellent heat resistance and durability of catalytic activity, it is extremely suitable as an exhaust gas purification catalyst carrying a platinum group metal, promotes decomposition of hydrocarbons, oxidation of NOx and carbon, etc., and exhaust gas from automobiles, etc. Can be purified cleanly.
排ガス浄化用触媒として使用される白金族金属としては、白金、パラジウム、ロジウム、イリジウム、ルテニウムが代表的であるが、何れも極めて高価な貴金属である。このため、触媒活性を長期間にわたって維持させることができる本発明の排ガス浄化用触媒は、大幅なコストダウンを図ることができる。
また、上述した触媒担体として使用されるシリカ分散アルミナは、特に高価な白金族触媒以外にも、水素化精製触媒、水素化脱硫触媒、水素化脱窒素触媒等の触媒としての機能を有する他の金属、例えば、クロム、モリブデン、タングステン、鉄、コバルト、ニッケル、オスミウム、モリブデン−コバルト、モリブデン−ニッケル、タングステン−ニッケル、モリブデン−コバルト−ニッケル、タングステン−コバルト−ニッケルまたはモリブデン−タングステン−コバルト−ニッケル等を、必要に応じて担持させ、各種の触媒として使用することもできる。
Typical platinum group metals used as exhaust gas purifying catalysts are platinum, palladium, rhodium, iridium and ruthenium, all of which are extremely expensive noble metals. For this reason, the exhaust gas purifying catalyst of the present invention capable of maintaining the catalytic activity for a long period of time can greatly reduce the cost.
Further, the silica-dispersed alumina used as the above-described catalyst carrier is not limited to a particularly expensive platinum group catalyst, but has other functions as a catalyst such as a hydrorefining catalyst, hydrodesulfurization catalyst, hydrodenitrogenation catalyst. Metals such as chromium, molybdenum, tungsten, iron, cobalt, nickel, osmium, molybdenum-cobalt, molybdenum-nickel, tungsten-nickel, molybdenum-cobalt-nickel, tungsten-cobalt-nickel or molybdenum-tungsten-cobalt-nickel Can be supported as required and used as various catalysts.
金属触媒の担持方法としては、上述したシリカ分散アルミナの成形体（担体）を触媒金属の可溶性塩の溶液に浸漬し、該金属成分を担体中に導入する含浸法、或いは担体の製造の際、金属成分を同時に沈殿させる共沈法等、公知の方法を採用することができるが、操作上容易であり、触媒特性の安定化維持に好都合な含浸法によることが好ましい。例えば、担体を常温または常温以上で含浸溶液に浸漬して所望成分が十分担体中に含浸する条件下で保持するのがよい。含浸溶液の量および温度は、所望量の触媒金属成分が担持されるように適宜調整することができる。また、触媒金属成分の所望担持量により含浸溶液に浸漬する担体の量を決定することができる。 As a method for supporting the metal catalyst, the above-mentioned silica-dispersed alumina molded body (support) is immersed in a solution of a soluble salt of the catalyst metal, and the impregnation method in which the metal component is introduced into the support; Known methods such as a coprecipitation method for simultaneously precipitating metal components can be employed, but it is preferable to use an impregnation method that is easy in operation and convenient for maintaining the stabilization of catalyst characteristics. For example, the support may be immersed in an impregnation solution at room temperature or above and kept under conditions where the desired component is sufficiently impregnated in the support. The amount and temperature of the impregnating solution can be appropriately adjusted so that a desired amount of the catalytic metal component is supported. Further, the amount of the carrier immersed in the impregnation solution can be determined by the desired loading amount of the catalytic metal component.
尚、二種以上の触媒金属成分を担持するには、二種以上の触媒金属成分をあらかじめ混合し、その混合溶液から同時に含浸する一液含浸法を採用することができるし、また、二種以上の金属成分の溶液を別々に調製し、逐次含浸していく二液含浸法を採用することもできる。 In order to support two or more types of catalytic metal components, a one-component impregnation method in which two or more types of catalytic metal components are mixed in advance and simultaneously impregnated from the mixed solution can be adopted. A two-component impregnation method in which the above metal component solutions are separately prepared and sequentially impregnated can also be employed.
本発明を、次の実験例により詳細に説明する。
尚、以下の実験に用いた各種の測定方法は次の通りである。
The present invention will be described in detail by the following experimental examples.
Various measurement methods used in the following experiments are as follows.
（１）化学分析；
Ｓｉ、Ａｌの測定はＪＩＳ．Ｍ．８８５３に準拠して測定した。
(1) Chemical analysis;
Si and Al are measured according to JIS. M.M. Measured according to 8853.
（２）ＢＥＴ比表面積、細孔容積および細孔分布；
Ｍｉｃｒｏｍｅｒｉｔｉｃｓ社製ＴｒｉＳｔａｒＩＩ ３０２０を用いて窒素吸着法にて測定を行った。細孔容積は、脱離側窒素吸着等温線からＢＪＨ法で求めた細孔分布において細孔直径２．０ｎｍ〜５０ｎｍまでの細孔容積を積算して求めた。比表面積は比圧が０．０５から０．２０の吸着側窒素吸着等温線からＢＥＴ法で解析した。細孔直径はＰ／Ｐ０＝０．９７５未満のＮ２吸着量をＶとし、比表面積をＡとして４Ｖ／Ａより計算して求めた。
(2) BET specific surface area, pore volume and pore distribution;
Measurement was performed by a nitrogen adsorption method using TriStarII 3020 manufactured by Micromeritics. The pore volume was determined by integrating the pore volumes from 2.0 nm to 50 nm in pore diameter in the pore distribution determined by the BJH method from the desorption side nitrogen adsorption isotherm. The specific surface area was analyzed by the BET method from the adsorption side nitrogen adsorption isotherm having a specific pressure of 0.05 to 0.20. The pore diameter was determined by calculating from 4 V / A, where V is the N 2 adsorption amount of less than P / P 0 = 0.975, and A is the specific surface area.
（３）電子顕微鏡観察（ＴＥＭ−ＥＤＸ）および画像解析；
透過型電子顕微鏡で２００，０００倍の倍率で観察したＴＥＭ像を用いて、ＥＤＸ分析を行ってＳｉをマッピングし、これを画像解析ソフト「ＩｍａｇｅＪ」を用いて解析し９０，０００ｎｍ２中のＳｉ粒子占有率を求めた。
(3) Electron microscope observation (TEM-EDX) and image analysis;
Using a TEM image observed with a transmission electron microscope at a magnification of 200,000, EDX analysis was performed to map Si, and this was analyzed using image analysis software “ImageJ”, and Si in 90,000 nm 2 The particle occupancy was determined.
（４）触媒調製（エージング）；
シリカ分散アルミナに対して０．７５ｗｔ％Ｐｔ＋０．２５ｗｔ％Ｐｄとなるように白金およびパラジウムのジニトロジアンミン硝酸溶液を含浸担持し、水素中４００℃で還元し空気中５００℃で処理したものをエージング前試料とし、これを空気中７５０℃でエージング処理を行ったものをエージング後試料とした。
(4) Catalyst preparation (aging);
Before aging, impregnated and supported with a dinitrodiammine nitric acid solution of platinum and palladium to 0.75 wt% Pt + 0.25 wt% Pd with respect to silica-dispersed alumina, reduced at 400 ° C in hydrogen and treated at 500 ° C in air A sample which was aged at 750 ° C. in air was used as a sample after aging.
（５）ＨＣ、ＮＯ酸化活性評価；
常圧固定床流通反応法により行った。試料４０ｍｇに模擬排ガスとしてのＮＯ２００ｐｐｍ＋Ｃ１０Ｈ２２（デカン）１８０ｐｐｍ＋Ｃ１１Ｈ１０（α−メチルナフタレン）１８ｐｐｍ＋１０％Ｈ２Ｏ＋５％Ｏ２（Ｎ２希釈）を４００ｍＬ・ｍｉｎ−１流通させ、５００℃から階段状に降温し、ＨＣが５０％転化する温度、及び３５０℃におけるＮＯからＮＯ２への転化率を求めた。
(5) HC, NO oxidation activity evaluation;
It was carried out by a normal pressure fixed bed flow reaction method. A sample exhaust gas of NO200 ppm + C 10 H 22 (decane) 180 ppm + C 11 H 10 (α-methylnaphthalene) 18 ppm + 10% H 2 O + 5% O 2 (N 2 diluted) as 400 m · min −1 was passed through 400 mg · min −1 and stepped from 500 ° C. The temperature at which the HC was converted to 50% and the conversion rate from NO to NO 2 at 350 ° C. were determined.
（実施例１）
アルミナ源の原料として硫酸アルミニウム水溶液（Ａｌ２Ｏ３ １１．３％、ＳＯ３ １４．５％、ＳＧ １．２５）を使用した。シリカ源の原料として、ケイ酸ソーダ水溶液（ＳｉＯ２ ２２．５％、Ｎａ２Ｏ ７．２％、ＳＧ １．３０）と４５％濃度の硫酸を用い、両者が瞬時接触可能な装置を用いてケイ酸ソーダ水溶液７．５Ｌ／ｍｉｎ、硫酸２．０Ｌ／ｍｉｎを該装置に供給し、この溶液に等倍の水を加えて酸性シリカゾルを調製した。硫酸アルミニウム水溶液１５００ｇに対し、酸性シリカゾルを所定量（表１参照）注加し攪拌混合したものを、水３０００ｍＬと４９％苛性ソーダ３１４ｇを混ぜ６０℃に加熱した容器に注加し、６０℃に加温したイオン交換水で、洗浄液が１μＳ／ｃｍ以下になるまで洗浄してシリカ分散アルミナヒドロゲル４種類を得た。このゲルを３００ｍＬビーカーにそれぞれ１５０ｍＬずつ二等分して一方はそのまま１５０℃で２４時間乾燥し、もう一方はアルミ箔で上部を覆うことで水熱雰囲気とし１５０℃で２４時間乾燥しキセロゲル８種を得た。得られたキセロゲルのうちアルミ箔を使用せずに乾燥したものを３６ｍＬの坩堝に１５．６ｇ分取して蓋をして６２０℃で２時間焼成し、アルミ箔を使用したものについては３６ｍＬの坩堝に１５．６ｇずつ分取して片方はそのまま６２０℃で２時間焼成し、もう一方は蓋をして６２０℃で２時間焼成してシリカ分散アルミナ計１２種類（表１参照）を得た。得られたシリカ分散アルミナについて物性を測定し結果を表１に、この内、平均細孔直径が６．３〜６．７ｎｍのシリカ分散アルミナについてのＨＣ、ＮＯ酸化活性結果を図２に記した。
Example 1
An aluminum sulfate aqueous solution (Al 2 O 3 11.3%, SO 3 14.5%, SG 1.25) was used as a raw material for the alumina source. Using a silica silicate aqueous solution (SiO 2 22.5%, Na 2 O 7.2%, SG 1.30) and 45% sulfuric acid as raw materials for the silica source, both of which can be contacted instantaneously A sodium silicate aqueous solution ( 7.5 L / min) and sulfuric acid (2.0 L / min) were supplied to the apparatus, and an equal amount of water was added to the solution to prepare an acidic silica sol. A predetermined amount (see Table 1) of acidic silica sol was added to 1500 g of an aluminum sulfate aqueous solution and stirred and mixed. Washing was performed with warm ion-exchanged water until the cleaning liquid became 1 μS / cm or less, and four types of silica-dispersed alumina hydrogels were obtained. Divide this gel into two 150ml portions in a 300mL beaker, one is dried as it is at 150 ° C for 24 hours, and the other is covered with aluminum foil for 24 hours at 150 ° C in a hydrothermal atmosphere. Got. Of the obtained xerogel, the one dried without using aluminum foil was placed in a 36 mL crucible, covered and baked at 620 ° C. for 2 hours, and the one using aluminum foil was 36 mL. 15.6 g each was taken into a crucible, and one was baked as it was at 620 ° C. for 2 hours, and the other was covered and baked at 620 ° C. for 2 hours to obtain a total of 12 types of silica-dispersed alumina (see Table 1). . The physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 1. Of these, the results of HC and NO oxidation activity for silica-dispersed alumina having an average pore diameter of 6.3 to 6.7 nm are shown in FIG. .
（比較例１）
酸性シリカゾルを１５０ｇ使用し、乾燥にアルミ箔を使用せず、焼成に蓋を使用しないこと以外は実施例１と同様の操作でシリカ分散アルミナを得た。物性測定の結果を表１に示す。
(Comparative Example 1)
A silica-dispersed alumina was obtained in the same manner as in Example 1 except that 150 g of acidic silica sol was used, no aluminum foil was used for drying, and no lid was used for firing. The results of physical property measurement are shown in Table 1.
（比較例２）
乾燥にアルミ箔を使用せず、焼成に蓋を使用しないこと以外は実施例１と同様の操作でシリカ分散アルミナ４種を得た。物性測定の結果を表１に、この内、平均細孔直径が６．３〜６．７ｎｍのシリカ分散アルミナについてのＨＣ、ＮＯ酸化活性結果を図２に示す。
(Comparative Example 2)
Four types of silica-dispersed alumina were obtained in the same manner as in Example 1 except that no aluminum foil was used for drying and no lid was used for firing. The physical property measurement results are shown in Table 1, and among these, the HC and NO oxidation activity results for silica-dispersed alumina having an average pore diameter of 6.3 to 6.7 nm are shown in FIG.
（比較例３）
酸性シリカゾルを１９ｇ使用したこと以外は実施例１と同様の操作でキセロゲル２種を得た。得られたキセロゲルを１種につき３６ｍＬの坩堝２個にそれぞれ１５．６ｇずつ分取して、一方は蓋をし、もう一方はそのままで６２０℃で２時間焼成してシリカ分散アルミナ４種を得た。得られたシリカ分散アルミナについて物性測定の結果を表１に、この内、平均細孔直径が６．３〜６．７ｎｍのシリカ分散アルミナについてのＨＣ、ＮＯ酸化活性結果を図２に示す。
(Comparative Example 3)
Two types of xerogel were obtained by the same operation as in Example 1 except that 19 g of acidic silica sol was used. 15.6g each of the obtained xerogel was dispensed into two 36mL crucibles of one type, one was capped, and the other was baked at 620 ° C for 2 hours to obtain four types of silica-dispersed alumina. It was. Table 1 shows the results of measuring physical properties of the obtained silica-dispersed alumina, and FIG. 2 shows the results of HC and NO oxidation activity for silica-dispersed alumina having an average pore diameter of 6.3 to 6.7 nm.
（比較例４）
酸性シリカゾルではなくコロイダルシリカ「スノーテックス２０Ｌ」を３４．５ｇ使い、乾燥にアルミ箔を使用せず、焼成に蓋を使用しないこと以外は実施例１と同様の操作を行い試料を得た。物性測定結果を表１に示す。
(Comparative Example 4)
A sample was obtained in the same manner as in Example 1 except that 34.5 g of colloidal silica “Snowtex 20L” was used instead of acidic silica sol, no aluminum foil was used for drying, and no lid was used for firing. The physical property measurement results are shown in Table 1.
表１より、本発明のシリカ分散アルミナ（実施例１−３、６、９、１２）は乾燥、焼成をスチーム下で行うことで熱処理による細孔の収縮が抑制され、さらにはＳｉ含有量の増大に伴う細孔の小径化も有効に抑制されており、比較例１と比較して高いＨＣ、ＮＯ酸化活性を示す。更に、実施例１は微細なシリカが均一分散することにより、エージング後でも失活せず、比較例４と比較して高い活性を示すことが特徴である。 From Table 1, the silica-dispersed alumina of the present invention (Examples 1-3, 6, 9, and 12) is dried and fired under steam to suppress pore shrinkage due to heat treatment. The reduction in the diameter of the pores accompanying the increase is also effectively suppressed, and shows higher HC and NO oxidation activity than Comparative Example 1. Further, Example 1 is characterized in that fine silica is uniformly dispersed, so that it does not deactivate even after aging, and exhibits higher activity than Comparative Example 4.
（実施例２）
酸性シリカゾルを１５０ｇ使ったこと以外は実施例１と同様の操作でアルミナヒドロゲルを得た。このゲルを３００ｍＬビーカー３つに１００ｍＬずつ分取した。乾燥条件は１５０℃２４時間とし、一つはアルミ箔で蓋をして２４時間乾燥し、もう一つは１２時間乾燥後アルミ箔を剥がして引き続き１２時間乾燥し、残る一つは蓋をしないで乾燥して３種のキセロゲルを得た。これらのキセロゲルを容積が３６ｍＬの坩堝に１０ｇずつ分取し、蓋をすることで水熱雰囲気とし６２０℃で２時間焼成してシリカ分散アルミナ３種類（表２参照）を得た。得られたシリカ分散アルミナについて物性を測定し、結果を表２および図３に示す。
(Example 2)
An alumina hydrogel was obtained in the same manner as in Example 1 except that 150 g of acidic silica sol was used. 100 mL of this gel was dispensed into three 300 mL beakers. Drying conditions are 150 ° C. for 24 hours, one is covered with aluminum foil and dried for 24 hours, the other is dried for 12 hours, then the aluminum foil is peeled off and then dried for 12 hours, and the other is not covered. And dried to obtain three types of xerogel. 10 g of each of these xerogels was taken into a crucible having a volume of 36 mL and capped to form a hydrothermal atmosphere and fired at 620 ° C. for 2 hours to obtain three types of silica-dispersed alumina (see Table 2). Physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 2 and FIG.
（実施例３）
アルミナヒドロゲルを３００ｍＬビーカー３つに２００ｍＬずつ分取した以外は実施例２と同様の操作を行い３種のシリカ分散アルミナ（表２参照）を得た。得られたシリカ分散アルミナについて物性を測定し、結果を表２および図３に示す。
(Example 3)
Three types of silica-dispersed alumina (see Table 2) were obtained in the same manner as in Example 2 except that 200 mL each of the alumina hydrogel was dispensed into three 300 mL beakers. Physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 2 and FIG.
（実施例４）
アルミナヒドロゲルを３００ｍＬビーカー３つに３００ｍＬずつ分取した以外は実施例２と同様の操作を行い３種のシリカ分散アルミナ（表２参照）を得た。得られたシリカ分散アルミナについて物性を測定し、結果を表２および図３に示す。
Example 4
Three types of silica-dispersed alumina (see Table 2) were obtained in the same manner as in Example 2 except that 300 mL each of the alumina hydrogel was dispensed into three 300 mL beakers. Physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 2 and FIG.
表２より、本発明のシリカ分散アルミナ（実施例２、３、４）は仕込み量にかかわらずスチーム条件での乾燥時間が長いほど細孔の収縮が抑制される。 From Table 2, the silica-dispersed alumina of the present invention (Examples 2, 3, and 4) suppresses the shrinkage of the pores as the drying time under the steam condition is longer regardless of the charged amount.
（実施例５）
酸性シリカゾルを１５０ｇ使ったこと以外は実施例１と同様の操作でアルミナヒドロゲルを得た。このゲルを３００ｍＬビーカーに３００ｍＬ分取しアルミ箔で蓋をしないで１５０℃で２４時間乾燥してキセロゲルを得た。得られたキセロゲルを３６ｍＬの坩堝にそれぞれ所定量（表３参照）分取して蓋をした。これらのキセロゲルを６２０℃で２時間の焼成処理を行う課程で一定時間毎に蓋を外すことで水熱処理時間の異なるシリカ分散アルミナ１２種類を得た。得られたシリカ分散アルミナについて物性を測定し、結果を表３および図４に示す。
(Example 5)
An alumina hydrogel was obtained in the same manner as in Example 1 except that 150 g of acidic silica sol was used. 300 mL of this gel was dispensed into a 300 mL beaker and dried at 150 ° C. for 24 hours without covering with aluminum foil to obtain a xerogel. The obtained xerogel was dispensed into a 36 mL crucible in predetermined amounts (see Table 3) and covered. Twelve types of silica-dispersed alumina with different hydrothermal treatment times were obtained by removing the lids at regular intervals in the course of firing these xerogels at 620 ° C. for 2 hours. Physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 3 and FIG.
（比較例５）
３６ｍＬの坩堝に蓋をしないで６２０℃で２時間焼成したこと以外は実施例５と同様の操作で３種類のシリカ分散アルミナを得た。得られたシリカ分散アルミナについて物性を測定し、結果を表３および図４に示す。
(Comparative Example 5)
Three types of silica-dispersed alumina were obtained in the same manner as in Example 5 except that the 36 mL crucible was baked at 620 ° C. for 2 hours without a lid. Physical properties of the obtained silica-dispersed alumina were measured, and the results are shown in Table 3 and FIG.
表３より、本発明のシリカ分散アルミナ（実施例５）は焼成をスチーム下で行うことで熱処理による細孔の収縮が比較例５よりも抑制され、特に６２０℃で１２０分間焼成する過程の始めの３０分を水熱処理することが細孔径を大きくする効果が高いことがわかる。また、焼成を行う際の試料充填量が坩堝容積を占める割合が多いほど（実施例５−１、４、７、１０）その効果が高いことがわかる。 From Table 3, the silica-dispersed alumina of the present invention (Example 5) is fired under steam so that pore shrinkage due to heat treatment is suppressed as compared with Comparative Example 5, and in particular, the beginning of the process of firing at 620 ° C. for 120 minutes. It can be seen that hydrothermal treatment for 30 minutes is highly effective in increasing the pore size. Moreover, it turns out that the effect is so high that the sample filling amount at the time of baking occupies the ratio of a crucible volume (Examples 5-1, 4, 7, 10).
（実施例６）
実施例５−２で得られたシリカ分散アルミナを、前記測定方法（４）触媒調製の条件に従ってエージング前及びエージング後の試料を得た。エージング後の試料の一部を更に９００℃焼成して触媒調製温度の異なる排ガス浄化用触媒三種類を得た。得られた排ガス浄化用触媒について物性を測定し、結果を表４に示す。
(Example 6)
The silica-dispersed alumina obtained in Example 5-2 was obtained before and after aging in accordance with the measurement method (4) catalyst preparation conditions. A part of the sample after aging was further calcined at 900 ° C. to obtain three types of exhaust gas purifying catalysts having different catalyst preparation temperatures. The physical properties of the obtained exhaust gas purification catalyst were measured, and the results are shown in Table 4.
（比較例６）
酸性シリカゾルを使用しなかったこと以外は比較例２と同様の操作でアルミナを得た。これを実施例６の触媒調製条件と同様の操作を行い、触媒調製温度の異なる排ガス浄化用触媒三種類を得た。得られた排ガス浄化用触媒について物性を測定し、結果を表４に示す。
(Comparative Example 6)
Alumina was obtained in the same manner as in Comparative Example 2 except that no acidic silica sol was used. This was performed in the same manner as the catalyst preparation conditions of Example 6 to obtain three types of exhaust gas purifying catalysts having different catalyst preparation temperatures. The physical properties of the obtained exhaust gas purification catalyst were measured, and the results are shown in Table 4.
表４より、本発明のシリカ分散アルミナを用いた排ガス浄化用触媒（実施例６）は比較例６と比較して、９００℃で焼成したにも関わらず高いＨＣ、ＮＯ酸化活性を示すことがわかる。 From Table 4, it can be seen that the exhaust gas purifying catalyst (Example 6) using the silica-dispersed alumina of the present invention exhibits higher HC and NO oxidation activity compared with Comparative Example 6 despite being calcined at 900 ° C. Recognize.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013266289A JP6245695B2 (en) | 2012-12-26 | 2013-12-25 | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012282407 | 2012-12-26 | ||
| JP2012282407 | 2012-12-26 | ||
| JP2013266289A JP6245695B2 (en) | 2012-12-26 | 2013-12-25 | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014140839A JP2014140839A (en) | 2014-08-07 |
| JP6245695B2 true JP6245695B2 (en) | 2017-12-13 |
Family
ID=51422638
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013266289A Active JP6245695B2 (en) | 2012-12-26 | 2013-12-25 | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6245695B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6347443B2 (en) * | 2014-08-29 | 2018-06-27 | 国立研究開発法人産業技術総合研究所 | Alumina particles |
| JP7061299B2 (en) * | 2017-09-21 | 2022-04-28 | 水澤化学工業株式会社 | Exhaust gas purification catalyst carrier made of two-metal dispersed Al oxide |
| CN115007125A (en) * | 2022-07-08 | 2022-09-06 | 湘潭大学 | Sepiolite-loaded manganese-cerium composite catalyst and preparation method and application thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0829931B2 (en) * | 1988-08-17 | 1996-03-27 | 東燃株式会社 | Heat-resistant inorganic porous composition and catalyst carrier comprising the same |
| JPH0275341A (en) * | 1988-09-12 | 1990-03-15 | Tonen Corp | Heat-resistant catalyst carrier molding and catalyst prepared therefrom |
| JPH02237640A (en) * | 1988-11-30 | 1990-09-20 | Tonen Corp | Heat resistant catalyst carrier and catalyst for combustion |
| JP2000070730A (en) * | 1998-08-27 | 2000-03-07 | Sumitomo Metal Mining Co Ltd | Production of spherical carrier for carrying catalyst |
| JP5828478B2 (en) * | 2012-03-14 | 2015-12-09 | 国立研究開発法人産業技術総合研究所 | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst |
-
2013
- 2013-12-25 JP JP2013266289A patent/JP6245695B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014140839A (en) | 2014-08-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4791445B2 (en) | Compositions based on oxides of zirconium, praseodymium, lanthanum or neodymium, their preparation and use in catalyst systems | |
| JP5148268B2 (en) | Zirconium and yttrium based compositions, processes for their preparation and their use in catalyst systems | |
| US20090098032A1 (en) | Methods of making aluminosilicate coated alumina | |
| CA2781794C (en) | Complex oxide, method for producing same and exhaust gas purifying catalyst | |
| JP4459170B2 (en) | Compositions based on cerium oxide and zirconium oxide and having a specific surface area that is stable at 900 ° C. to 1000 ° C., their production method and their use as catalysts | |
| JP5564109B2 (en) | Composition comprising cerium oxide and zirconium oxide with specific porosity, its preparation method and its use in catalysis | |
| JP5350249B2 (en) | Method for treating diesel engine exhaust gas, method for producing a structure of alumina particles useful as a support component for noble metal catalyst for controlling harmful emissions of diesel engine, and catalyst composition for treating diesel engine exhaust gas | |
| JP5801411B2 (en) | Composition based on zirconium oxide and at least one oxide of rare earth elements other than cerium, having a unique porosity, its production process and its use in catalysis | |
| EP1832345A1 (en) | Catalyst for exhaust gas purification | |
| JP5952293B2 (en) | Sulfur resistant alumina catalyst support | |
| WO2001072417A1 (en) | Desulfurizing agent for hydrocarbon derived from petroleum, method for producing hydrogen for use in fuel cell and method for producing nickel-based desulfurizing agent | |
| JP5335505B2 (en) | Noble metal support and method for producing carboxylic acid ester using the same as catalyst | |
| JP2001170500A (en) | Porous body, method of producing the same and exhaust gas purification catalyst using the porous body | |
| JP6245695B2 (en) | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst | |
| JP2012040550A (en) | Catalyst precursor dispersion, catalyst, and cleaning method of exhaust gas | |
| JP6236647B2 (en) | Alumina particles | |
| KR102608017B1 (en) | Hydrocarbon oil catalyst, production method, and hydrogenation method thereof | |
| RU2660430C2 (en) | Hydrogenation catalyst carrier, its production method, hydrogenation catalyst and the hydrogenation catalyst production method | |
| JP5828478B2 (en) | Exhaust gas purification catalyst carrier and exhaust gas purification catalyst | |
| JP6347443B2 (en) | Alumina particles | |
| JP5116377B2 (en) | Exhaust NOx purification method | |
| JP2009056456A (en) | Method for manufacturing catalytic carrier | |
| JP2007069095A (en) | Carrier of catalyst for nox purification | |
| JP2008215253A (en) | NOx EMISSION CONTROL METHOD AND NOx EMISSION CONTROL DEVICE | |
| JP7061299B2 (en) | Exhaust gas purification catalyst carrier made of two-metal dispersed Al oxide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20160808 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20160805 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20170410 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20170418 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20170612 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20170801 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20170929 |
|
| 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: 20171031 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20171110 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6245695 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |