JP5119508B2 - PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same - Google Patents
PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same Download PDFInfo
- Publication number
- JP5119508B2 JP5119508B2 JP2006067915A JP2006067915A JP5119508B2 JP 5119508 B2 JP5119508 B2 JP 5119508B2 JP 2006067915 A JP2006067915 A JP 2006067915A JP 2006067915 A JP2006067915 A JP 2006067915A JP 5119508 B2 JP5119508 B2 JP 5119508B2
- Authority
- JP
- Japan
- Prior art keywords
- combustion
- composite oxide
- exhaust gas
- oxidation catalyst
- catalyst
- 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.)
- Expired - Fee Related
Links
- 238000002485 combustion reaction Methods 0.000 title claims description 52
- 239000003054 catalyst Substances 0.000 title claims description 46
- 238000000034 method Methods 0.000 title claims description 25
- 230000003647 oxidation Effects 0.000 title claims description 14
- 238000007254 oxidation reaction Methods 0.000 title claims description 14
- 238000000746 purification Methods 0.000 title claims description 14
- 239000002131 composite material Substances 0.000 claims description 43
- 229910052684 Cerium Inorganic materials 0.000 claims description 30
- 229910052742 iron Inorganic materials 0.000 claims description 21
- 239000006104 solid solution Substances 0.000 claims description 12
- 229910052783 alkali metal Inorganic materials 0.000 claims description 10
- 150000001340 alkali metals Chemical class 0.000 claims description 10
- 229910052701 rubidium Inorganic materials 0.000 claims description 5
- 229910052792 caesium Inorganic materials 0.000 claims description 4
- 229910052700 potassium Inorganic materials 0.000 claims description 4
- 239000011572 manganese Substances 0.000 description 54
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 39
- 239000002245 particle Substances 0.000 description 32
- 229910052748 manganese Inorganic materials 0.000 description 21
- 229910052723 transition metal Inorganic materials 0.000 description 21
- 150000003624 transition metals Chemical class 0.000 description 21
- 239000000203 mixture Substances 0.000 description 20
- 230000000052 comparative effect Effects 0.000 description 19
- 239000007789 gas Substances 0.000 description 19
- 230000000694 effects Effects 0.000 description 12
- 238000002441 X-ray diffraction Methods 0.000 description 9
- 239000000843 powder Substances 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 8
- 238000004458 analytical method Methods 0.000 description 7
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 7
- 239000006229 carbon black Substances 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 229910052802 copper Inorganic materials 0.000 description 5
- 239000010949 copper Substances 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- FJDQFPXHSGXQBY-UHFFFAOYSA-L caesium carbonate Chemical compound [Cs+].[Cs+].[O-]C([O-])=O FJDQFPXHSGXQBY-UHFFFAOYSA-L 0.000 description 4
- 229910000024 caesium carbonate Inorganic materials 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 229910052759 nickel Inorganic materials 0.000 description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- WPFGFHJALYCVMO-UHFFFAOYSA-L rubidium carbonate Chemical compound [Rb+].[Rb+].[O-]C([O-])=O WPFGFHJALYCVMO-UHFFFAOYSA-L 0.000 description 4
- 229910000026 rubidium carbonate Inorganic materials 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000002411 thermogravimetry Methods 0.000 description 3
- 229910052720 vanadium Inorganic materials 0.000 description 3
- 229910052725 zinc Inorganic materials 0.000 description 3
- 239000011701 zinc Substances 0.000 description 3
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 2
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 description 2
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910000027 potassium carbonate Inorganic materials 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 229910052706 scandium Inorganic materials 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- IBMCQJYLPXUOKM-UHFFFAOYSA-N 1,2,2,6,6-pentamethyl-3h-pyridine Chemical compound CN1C(C)(C)CC=CC1(C)C IBMCQJYLPXUOKM-UHFFFAOYSA-N 0.000 description 1
- JIPBPJZISZCBJQ-UHFFFAOYSA-N 1-[(2-methylpropan-2-yl)oxycarbonyl]-3-(pyridin-4-ylmethyl)piperidine-3-carboxylic acid Chemical compound C1N(C(=O)OC(C)(C)C)CCCC1(C(O)=O)CC1=CC=NC=C1 JIPBPJZISZCBJQ-UHFFFAOYSA-N 0.000 description 1
- YPFNIPKMNMDDDB-UHFFFAOYSA-K 2-[2-[bis(carboxylatomethyl)amino]ethyl-(2-hydroxyethyl)amino]acetate;iron(3+) Chemical compound [Fe+3].OCCN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O YPFNIPKMNMDDDB-UHFFFAOYSA-K 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
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910018378 Mn(NO3)2-6H2O Inorganic materials 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004455 differential thermal analysis 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
- 238000011156 evaluation Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 150000004687 hexahydrates Chemical class 0.000 description 1
- QZRHHEURPZONJU-UHFFFAOYSA-N iron(2+) dinitrate nonahydrate Chemical compound O.O.O.O.O.O.O.O.O.[Fe+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O QZRHHEURPZONJU-UHFFFAOYSA-N 0.000 description 1
- 229910052747 lanthanoid Inorganic materials 0.000 description 1
- 150000002602 lanthanoids Chemical class 0.000 description 1
- FUJCRWPEOMXPAD-UHFFFAOYSA-N lithium oxide Chemical compound [Li+].[Li+].[O-2] FUJCRWPEOMXPAD-UHFFFAOYSA-N 0.000 description 1
- 229910001947 lithium oxide Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 239000013618 particulate matter Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000000634 powder X-ray diffraction Methods 0.000 description 1
- FGLXSQPIVUPIKK-UHFFFAOYSA-N praseodymium(3+) trinitrate tetrahydrate Chemical compound O.O.O.O.[N+](=O)([O-])[O-].[Pr+3].[N+](=O)([O-])[O-].[N+](=O)([O-])[O-] FGLXSQPIVUPIKK-UHFFFAOYSA-N 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 description 1
- 229910052815 sulfur oxide Inorganic materials 0.000 description 1
- 229910001936 tantalum oxide Inorganic materials 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- 150000003755 zirconium compounds Chemical class 0.000 description 1
Images
Landscapes
- Processes For Solid Components From Exhaust (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Description
本発明は、自動車用をはじめとしたディーゼル機関等からの排ガス中に含有され、炭素質の煤等からなる粒子状物質（ＰＭという。）の燃焼温度を低減させる触媒、並びにこれを用いたディーゼル機関排ガスの浄化方法、フィルター及び浄化装置に関するものである。 The present invention relates to a catalyst for reducing the combustion temperature of particulate matter (referred to as PM), which is contained in exhaust gas from automobiles and other diesel engines, etc., and is composed of carbonaceous soot, etc., and diesel using the same The present invention relates to an engine exhaust gas purification method, a filter, and a purification device.
近年、ディーゼル車から排出されるＮＯX、ＰＭは環境汚染や人体への影響が懸念されることから、より一層の低減が求められるようになっており、年々その規制は強化される傾向にある。ガソリン機関では三元触媒など排ガス処理技術の進歩はめざましいものがあるが、ディーゼル機関では、排ガス中の酸素量が多いこと、ＰＭや硫黄酸化物を多く含むため、これらガソリン機関で利用されているこれらの技術を応用できないことは広く知られたところである。 In recent years, there is NO X emitted from diesel vehicles, PM from the fact that the impact on the environment pollution and the human body is concerned, more has become so that further reduction is required, tend the regulations to be strengthened year by year . Gasoline engines, such as three-way catalysts, have made remarkable progress in exhaust gas treatment technology, but diesel engines are used in these gasoline engines because they contain a large amount of oxygen in the exhaust gas and contain a large amount of PM and sulfur oxides. It is widely known that these techniques cannot be applied.
このため、ディーゼル機関ではガソリン機関とは異なった排ガスの浄化方法を検討、導入することによって、排ガス浄化技術を確立してきた。例えば、排ガスの処理部分に対して、コーディライトや炭化ケイ素(ＳｉＣ)を用いたフィルター(ＤＰＦ)を配置してＰＭの除去を行う方法や、ディーゼル機関内の燃焼効率の向上技術の開発といったことが主として挙げられる。 For this reason, exhaust gas purification technology has been established by investigating and introducing exhaust gas purification methods different from those for gasoline engines in diesel engines. For example, a method of removing PM by placing a filter (DPF) using cordierite or silicon carbide (SiC) on the exhaust gas treatment part, or development of technology for improving combustion efficiency in diesel engines Is mainly mentioned.
ところで、上記技術の中で排ガス中のＰＭを除去する際には、排ガスから「濾しとった」あとのＰＭの処理が重要となる。主として利用されている方法は、周期的にフィルターそのものを加熱することによって、フィルター内に滞留しているＰＭ成分を燃焼除去することが挙げられる。概説すると、フィルターの外部から電熱ヒータ等を使用し、強制的にフィルターの温度を上げてＰＭ成分を燃焼する機構を供えた装置であり、ＰＭの焼却燃焼といった観点では優れた機構といえる。 By the way, when removing the PM in the exhaust gas in the above technique, it is important to treat the PM after being “filtered” from the exhaust gas. As a method mainly used, it is mentioned that the PM component staying in the filter is burned and removed by periodically heating the filter itself. In summary, this is an apparatus provided with a mechanism for burning the PM component by forcibly raising the temperature of the filter by using an electric heater or the like from the outside of the filter, and can be said to be an excellent mechanism from the viewpoint of incineration combustion of PM.
この機構において、フィルターを含むディーゼル機関排ガス浄化装置の耐熱仕様度低減によるコストの削減、フィルター加熱コストの削減などを図るべく、燃焼用の触媒をフィルター中に担持することによってディーゼル機関排ガス中のＰＭの主成分であるカーボンの燃焼開始温度を低減させることが検討されている。 In this mechanism, in order to reduce the cost by reducing the heat resistance specification of the diesel engine exhaust gas purification device including the filter and reduce the filter heating cost, the PM in the exhaust gas of the diesel engine is supported by supporting the combustion catalyst in the filter. It has been studied to reduce the combustion start temperature of carbon, which is the main component of carbon.
例えば、検討・開示されている内容について列挙すると、触媒に白金族およびアルカリ土類金属を表面に形成させることで燃焼開始温度を低下させること(特許文献１)、触媒成分として貴金属と酸素保存成分を含むものを使用すること(特許文献２)、低温において二酸化窒素を捕捉する効果を持った触媒を担持させること(特許文献３)、酸化スズや酸化タンタルに白金族を担持すること(特許文献４)、排気中の一酸化窒素と酸素を選択的に反応させた後にそこで生成した二酸化窒素を用いてＰＭ成分を燃焼させる仕組みを用いること(特許文献５)などが挙げられる。 For example, the contents that have been studied and disclosed are listed. The catalyst is formed with platinum group and alkaline earth metal on the surface to lower the combustion start temperature (Patent Document 1). (Patent document 2), supporting a catalyst having an effect of capturing nitrogen dioxide at a low temperature (patent document 3), supporting a platinum group on tin oxide or tantalum oxide (patent document 2) 4) Use of a mechanism in which nitrogen monoxide and oxygen in the exhaust gas are selectively reacted and then the PM component is combusted using the nitrogen dioxide generated there (Patent Document 5).
また、ＰＭ燃焼を助けるような効果を有する触媒としては、酸化リチウムなどの触媒活性物質上を通過させるもの(特許文献６)、ＶやＷの酸化物とパラジウムを触媒成分として使用するもの(特許文献７)、酸化触媒にペロブスカイト複合酸化物を使用するもの(特許文献８)等がある。 Catalysts that have an effect of assisting PM combustion include those that pass over catalytically active substances such as lithium oxide (Patent Document 6), and those that use V and W oxides and palladium as catalyst components (patents). Document 7) and those using a perovskite complex oxide as an oxidation catalyst (Patent Document 8).
さらに、ＭｎやＣｅを使用するような触媒に関しては、セリウムもしくはジルコニウム化合物の担体に触媒成分としてＭｎ等を担持することで酸化触媒として使用する方法(特許文献９)、金、銀、銅、鉄、亜鉛、マンガン、セリウムおよび白金族元素といった数多くの成分からの一種もしくは二種以上の組み合わせによって酸化触媒を構成させるもの(特許文献１０)、および耐火性担体に対してＭｎを担持することによってＰＭを燃焼させる方法(特許文献１１)がある。
ところが、ほとんどの従来技術は白金をはじめとした白金族元素や貴金属を併用して使用しており、コスト面での改善が問題となっている。これに加えて、排ガス中のＰＭの燃焼開始温度がまだ高いという問題もある。
そこで、本発明の解決すべき技術的課題としては、より安価で提供でき、かつさらに低温でＰＭを燃焼させ得る触媒、及びそれを用いた浄化装置並びにそれを用いた排ガス浄化方法の提供とする。
However, most conventional techniques use platinum group elements such as platinum and noble metals in combination, and there is a problem of cost improvement. In addition, there is a problem that the combustion start temperature of PM in the exhaust gas is still high.
Therefore, the technical problem to be solved by the present invention is to provide a catalyst that can be provided at a lower cost and that can burn PM at a lower temperature, a purification device using the catalyst, and an exhaust gas purification method using the catalyst. .
上記課題を解決する手段として、従来技術において必須であった白金族元素や貴金属の使用を一切要せず且つＰＭの燃焼開始温度を従来技術よりも大幅に低下せしめる触媒を提供すべく取り組んだ結果、本発明者らが到達した発明は、
（１）ＰＭ燃焼用酸化触媒として遷移金属とＣｅとの複合酸化物を使用すること
（２）さらにその効果を高めるため、アルカリ金属を含有させること
（３）上記遷移金属がＳｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎの少なくとも一種であること、好ましくはＭｎまたはＦｅであること
（４）Ｃｅ／（Ｃｅ＋遷移金属）のモル比を１.０未満、遷移金属としてＭｎを選択した場合には０.１より大で１.０未満、好ましくは０.２以上０.９未満、Ｆｅを選択した場合には０.５より大で１.０未満とすること
（５）上記遷移金属とＣｅとが固溶体を形成していること
（６）アルカリ金属が好ましくはＫ、Ｒｂ、Ｃｓの少なくとも一種であること
（７）上記複合酸化物において前記アルカリ金属／（遷移金属＋Ｃｅ）のモル比が１未満、好ましくは０.０５以上０.８未満であること
（８）上記の組成物を使用することによってＰＭ酸化開始温度を低減させるディーゼル機関排ガスの浄化方法
（９）上記の組成物を用いたことを特徴とするディーゼル機関排ガスのフィルター及びそれを用いた浄化装置
が挙げられる。
Results of efforts to provide a catalyst that does not require the use of platinum group elements and noble metals that were essential in the prior art as a means to solve the above problems, and that can significantly lower the combustion start temperature of PM than in the prior art The invention reached by the inventors
(1) Use a composite oxide of transition metal and Ce as an oxidation catalyst for PM combustion (2) Add an alkali metal to further enhance the effect (3) The transition metal is Sc, Ti, V , Cr, Mn, Fe, Co, Ni, Cu, Zn, preferably Mn or Fe (4) Ce / (Ce + transition metal) molar ratio less than 1.0, transition metal When Mn is selected, it is greater than 0.1 and less than 1.0, preferably 0.2 or more and less than 0.9, and when Fe is selected, it should be greater than 0.5 and less than 1.0. (5) The transition metal and Ce form a solid solution. (6) The alkali metal is preferably at least one of K, Rb, and Cs. (7) In the composite oxide, the alkali metal / (transition Metal + Ce) molar ratio is less than 1 (8) Diesel engine exhaust gas purification method for reducing PM oxidation start temperature by using the above composition (9) Using the above composition A diesel engine exhaust gas filter and a purification device using the same.
本発明に係る触媒を使用することによりＰＭ燃焼開始温度の低減をはかることができ、かつ貴金属を使用することなく汎用性の高い元素で構成されているため、触媒、フィルターおよび浄化装置において低コスト化がはかれるとともに、酸化物により構成されているため経時的な触媒性能劣化の小さいことが期待される触媒を得ることができる。 By using the catalyst according to the present invention, the PM combustion start temperature can be reduced, and since it is composed of highly versatile elements without using precious metals, the catalyst, the filter and the purification device are low in cost. Thus, a catalyst that is expected to have little deterioration in catalyst performance over time can be obtained because it is composed of oxides.
以下に本発明についてさらに詳細に説明する。
はじめに本発明に係る触媒はＭｎ、Ｆｅをはじめとする遷移金属およびＣｅを含むことを特徴とする。複合酸化物中においてＣｅとＭｎ、Ｆｅをはじめとする遷移金属とは、混合したのみの混合物形態ではなく、酸化セリウムに対して遷移金属が固溶した状態にあることがより好ましい。この中に含まれる遷移金属とは周期律表の３族から１２族までの元素を表す。とりわけ４周期にある遷移元素(Ｓｃ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｚｎ)が好ましく、なかでもＭｎ、Ｆｅの元素を使用することがさらに好適である。
The present invention is described in further detail below.
First, the catalyst according to the present invention is characterized by containing transition metals such as Mn and Fe and Ce. In the composite oxide, the transition metal such as Ce, Mn, and Fe is preferably not in the form of a mixture, but in a state where the transition metal is in solid solution with respect to cerium oxide. The transition metal contained therein represents an element from group 3 to group 12 of the periodic table. In particular, transition elements (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn) in four periods are preferable, and it is more preferable to use elements of Mn and Fe.
また、遷移金属とＣｅの構成モル比としては、Ｃｅ／（遷移金属＋Ｃｅ）が１未満が好ましい。Ｃｅ／（遷移金属＋Ｃｅ）が１の場合は、ＣｅＯ2単独で存在することになり、本発明の意図とは離れてしまう。また、本発明者が同様の製法で作成したＣｅＯ2では、本発明に示すような燃焼開始温度低減効果を有する触媒粉末は得られなかった。極端にＣｅ／（遷移金属＋Ｃｅ）が０に近い場合には、複合酸化物中において遷移金属とＣｅが完全な固溶体を形成できず、燃焼開始温度低減効果が小さくなるため好ましくない。また、Ｍｎ、Ｆｅに関して発明者が独自に検討した方法によれば、元素により上記モル比の好ましい範囲は異なり、Ｍｎの場合では０.１より大で１.０未満、好ましくは０.２以上０.９未満の範囲、Ｆｅを選択する場合においては０.５より大で１.０未満の範囲が好ましいことがわかった。 Further, as the constituent molar ratio of the transition metal and Ce, Ce / (transition metal + Ce) is preferably less than 1. When Ce / (transition metal + Ce) is 1, CeO 2 exists alone, which is not the intention of the present invention. In addition, CeO 2 produced by the same production method by the inventor did not provide a catalyst powder having an effect of reducing the combustion start temperature as shown in the present invention. When Ce / (transition metal + Ce) is extremely close to 0, the transition metal and Ce cannot form a complete solid solution in the composite oxide, and the effect of reducing the combustion start temperature is reduced. Further, according to the method independently examined by the inventors regarding Mn and Fe, the preferred range of the molar ratio varies depending on the element. In the case of Mn, it is greater than 0.1 and less than 1.0, preferably 0.2 or more. It has been found that a range of less than 0.9 and a range of greater than 0.5 and less than 1.0 are preferable when Fe is selected.
また、複合酸化物はその組成中にアルカリ金属を含んだ方がカーボン（模擬ＰＭ）の燃焼開始温度がより低くなる傾向があり好ましい。このときに添加するアルカリ金属元素の量としては、モル比でアルカリ金属／（遷移金属＋Ｃｅ）が１未満の範囲が好ましく、より好ましくは０.８未満の範囲である。下限値に関しては０.０５である。特にアルカリ金属の中でも、Ｋ、Ｒｂ、Ｃｓ等の少なくとも一種を添加することにより、より燃焼開始温度低減の効果が得られるため好適である。 In addition, it is preferable that the composite oxide contains an alkali metal in its composition because the combustion start temperature of carbon (simulated PM) tends to be lower. The amount of the alkali metal element added at this time is preferably such that the alkali metal / (transition metal + Ce) is less than 1 in terms of molar ratio, more preferably less than 0.8. The lower limit is 0.05. In particular, among alkali metals, it is preferable to add at least one of K, Rb, Cs and the like because the effect of reducing the combustion start temperature can be obtained.
［遷移金属−Ｃｅ系触媒粉末の作成］
ここでは、複合酸化物中においてＣｅと遷移金属の主としてＭｎ又はＦｅとの固溶体を形成させた場合について記載するが、本発明の技術的範囲はこれらの特定の記載に限定されないことはもちろんである。
[Preparation of transition metal-Ce catalyst powder]
Here, a case where a solid solution of Ce and a transition metal mainly Mn or Fe is formed in the composite oxide will be described, but it is a matter of course that the technical scope of the present invention is not limited to these specific descriptions. .
［参考例1］
硝酸マンガン(II)６水和物 Ｍｎ（ＮＯ3）2６Ｈ2Ｏ（純度９９.９％、株式会社高純度化学研究所製）０.０１ｙｍｏｌと硝酸セリウム(III)６水和物Ｃｅ(ＮＯ3)3６Ｈ2Ｏ（純度９９.９％、株式会社高純度化学研究所製）０.０１(１−ｙ)ｍｏｌ(このときのｙはＭｎ／（Ｍｎ＋Ｃｅ）のモル比を表す。参考例１においてはｙ＝０.２５とした。)を水１５ｍＬに溶解させる。激しく撹拌しながら、２８％アンモニア水を滴下(１５ｍＬ)し共沈させる。
得られた物質を蒸発乾固し、９０℃の乾燥器で一晩乾燥させる。そうして得られた乾燥品粉末を空気中４５０℃(昇温速度３００℃／ｈ)で５時間焼成し、ＭｎとＣｅを主成分とする複合酸化物の触媒粉末を作成した。
[ Reference Example 1 ]
Manganese (II) nitrate hexahydrate Mn (NO 3 ) 2 6H 2 O (purity 99.9%, manufactured by Kojundo Chemical Laboratory Co., Ltd.) 0.01 ymol and cerium (III) nitrate hexahydrate Ce (NO 3 ) 3 6H 2 O (purity 99.9%, manufactured by Kojundo Chemical Laboratory Co., Ltd.) 0.01 (1-y) mol (where y is the molar ratio of Mn / (Mn + Ce). Reference Example 1 is set to y = 0.25) is dissolved in 15 mL of water. With vigorous stirring, 28% aqueous ammonia is added dropwise (15 mL) and coprecipitated.
The resulting material is evaporated to dryness and dried in a 90 ° C. oven overnight. The dried product powder thus obtained was calcined in air at 450 ° C. (
［本発明における評価方法］
（１）燃焼開始温度の測定
ＴＧ−ＤＴＡ装置を使用して、模擬ＰＭ粒子としてカーボンブラックの燃焼開始温度の測定を行った。なおここで、ＴＧはThermogravimetry（熱重量）、ＤＴＡはDifferential Thermal Analysis（示差熱）を指す。以下の全ての参考例、実施例及び比較例（ただし比較例１を除く）において混合割合は、複合酸化物触媒（比較例においては単独酸化物の場合を含む。）と模擬ＰＭ（カーボンブラック）の質量比が４：１になるように調整した。このときＴＧ測定装置としてはリガク製ＴＧ−ＤＴＡ装置Thermoplus TG８１２０を使用して測定した。装置内に流通させるガスの流量は、２０vol.％Ｏ2と残部をＮ2とした混合ガス中で、昇温速度は１０℃／分となるように調整後、測定を実施した。なお、燃焼開始温度は、ＴＧ曲線において、重量減少が始まる前の接線と重量減少率（角度）が最大となる点での接線との交点を燃焼開始温度として算出する。算出の方法を図５に示した。
（２）模擬ＰＭ（カーボンブラック）
三菱化学製カーボンブラック（平均粒径２.０９μｍ）を模擬ＰＭとして使用した。
[Evaluation method in the present invention]
(1) Measurement of combustion start temperature The combustion start temperature of carbon black was measured as simulated PM particles using a TG-DTA apparatus. Here, TG indicates Thermogravimetry (thermogravimetry) and DTA indicates Differential Thermal Analysis (differential heat). In all the following Reference Examples, Examples and Comparative Examples (except for Comparative Example 1), the mixing ratio is the composite oxide catalyst (including the case of a single oxide in the Comparative Example) and simulated PM (carbon black). The mass ratio was adjusted to 4: 1. At this time, it measured using TG-DTA apparatus Thermoplus TG8120 made from Rigaku as a TG measuring apparatus. The flow rate of the gas to be circulated in the apparatus was measured in a mixed gas in which 20 vol.% O 2 and the balance N 2 were adjusted so that the temperature rising rate was 10 ° C./min. The combustion start temperature is calculated as the combustion start temperature at the intersection of the tangent before the weight reduction starts and the tangent at the point where the weight reduction rate (angle) becomes maximum in the TG curve. The calculation method is shown in FIG.
(2) Simulated PM (carbon black)
Carbon black (average particle size: 2.09 μm) manufactured by Mitsubishi Chemical was used as a simulated PM.
（３）組成の分析
組成分析は堀場製作所製蛍光Ｘ線分析装置 MESA-５００Wを使用して行った。
（４）ＸＲＤ測定
結晶性の解析は粉末Ｘ線回折法を使用した。その際に使用した装置は島津製作所製のＸ線回折装置XD-D１を使用し、Cu-Kα線を使用して、管電圧３０ｋＶ、管電流３０ｍＡにて２θ＝１０〜７０°の角度をスキャンスピード２°／分の速度でスキャンすることにより回折を行った。
（５）比表面積の測定
比表面積の測定はＢＥＴ法を用いて行い、日本ベル株式会社製のBelsorpMINIを使用して測定した。
(3) Composition analysis The composition analysis was performed using a fluorescent X-ray analyzer MESA-500W manufactured by Horiba.
(4) XRD measurement The crystallinity was analyzed using a powder X-ray diffraction method. The X-ray diffractometer XD-D1 manufactured by Shimadzu Corporation was used as the equipment used at that time, and Cu-Kα rays were used to scan an angle of 2θ = 10 to 70 ° at a tube voltage of 30 kV and a tube current of 30 mA. Diffraction was performed by scanning at a speed of 2 ° / min.
(5) Measurement of specific surface area The specific surface area was measured using the BET method and measured using BelsorpMINI manufactured by Bell Japan Co., Ltd.
得られた触媒粉末は組成分析の結果、モル比Ｃｅ／（Ｍｎ＋Ｃｅ）＝０.７５の粒子になっており、図１に示すＸ線回折パターンを有するものだった。これをJCPDS（Joint Committee on Powder Diffraction Standards）パターンに当てはめるとＭｎ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、複合酸化物においてＭｎはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。
また得られた粒子のＢＥＴ値は８０.１ｍ2／ｇであり、ＴＧ（熱重量、Thermogravimetry）による燃焼開始温度は表１に示すように３３４℃と算出された。得られたＴＧ曲線を図３に示す。
As a result of the compositional analysis, the obtained catalyst powder was particles having a molar ratio Ce / (Mn + Ce) = 0.75, and had an X-ray diffraction pattern shown in FIG. When this was applied to a JCPDS (Joint Committee on Powder Diffraction Standards) pattern, no peak derived from Mn oxide was confirmed, and only the peak of Ce oxide occupying the majority was observed. It is presumed that it is in the form of a so-called solid solution that is taken in.
The BET value of the obtained particles was 80.1 m 2 / g, and the combustion start temperature by TG (Thermogravimetry) was calculated as 334 ° C. as shown in Table 1. The obtained TG curve is shown in FIG.
［参考例２〜５］
複合酸化物中のＣｅ／（Ｍｎ＋Ｃｅ）のモル比を表１（表１及び後述の表２中において遷移金属をＭで示す。）に記載のとおり変化させた以外は参考例１と同様に行った。その結果を表１に示す。
[ Reference Examples 2 to 5 ]
The same procedure as in Reference Example 1 was carried out except that the molar ratio of Ce / (Mn + Ce) in the composite oxide was changed as described in Table 1 (the transition metal is indicated by M in Table 1 and Table 2 described later). It was. The results are shown in Table 1.
［参考例６〜１１］
硝酸マンガン(II)６水和物を硝酸鉄９水和物に変更し、ＦｅとＣｅの割合を種々変化させた以外は参考例１と同様にして、ＦｅとＣｅからなる複合酸化物粉末を作成した。その結果を表１に示す。
また、参考例６で得られた複合酸化物のＸ線回折パターンを図２に示す。これを前記JCPDSパターンに当てはめると、Ｆｅ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、複合酸化物においてＦｅはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。参考例６のカーボンブラックの燃焼挙動を示すＴＧ曲線を図４に示す。
[ Reference Examples 6 to 11 ]
A composite oxide powder composed of Fe and Ce was prepared in the same manner as in Reference Example 1 except that manganese nitrate (II) hexahydrate was changed to iron nitrate nonahydrate and the ratio of Fe and Ce was variously changed. Created. The results are shown in Table 1.
Further, the X-ray diffraction pattern of the composite oxide obtained in Reference Example 6 is shown in FIG. When this was applied to the JCPDS pattern, the peak derived from Fe oxide was not confirmed, and only the peak of Ce oxide occupying the majority was observed, so that Fe was taken into Ce in the composite oxide. It is presumed that it is in the form of a so-called solid solution. A TG curve showing the combustion behavior of the carbon black of Reference Example 6 is shown in FIG.
［参考例１２〜１４］
参考例１において、Ｍｎに代えてＣｏ、Ｎｉ、Ｃｕを使用した以外は同様にして、Ｃｏ、Ｎｉ、ＣｕのそれぞれとＣｅとからなる複合酸化物を作成した。その結果を表１に示す。
[ Reference Examples 12 to 14 ]
A composite oxide composed of Co, Ni, Cu and Ce was prepared in the same manner as in Reference Example 1 , except that Co, Ni, and Cu were used instead of Mn. The results are shown in Table 1.
［参考例１５］
炭酸カリウム（Ｋ2ＣＯ3）を溶液濃度が０.６０ｍｏｌ／Ｌになるよう水に溶解させ調製した。こうして得た溶液を参考例１の方法で作成しておいたＭｎとＣｅの複合酸化物（モル比：Ｃｅ／（Ｍｎ＋Ｃｅ）＝０.７５）をるつぼに入れて９０℃に加熱しながら、調製した前記０.６０ｍｏｌ／Ｌの炭酸カリウム水溶液を撹拌させてＫ量でモル比：Ｋ／（Ｍｎ＋Ｃｅ）＝０.２５となる液量を徐々に滴下した。滴下終了後、よく混合し、９０℃に設定した乾燥器で一晩乾燥させた。そうして得られたＫ被着のＭｎ−Ｃｅ複合酸化物の乾燥品を空気中４５０℃（昇温速度３００℃／時間）で５時間焼成することによって、Ｋを含有するＭｎとＣｅの複合酸化物を得た。
得られた触媒粉末は組成分析の結果、モル比でＣｅ／（Ｍｎ＋Ｃｅ）＝０.７５、Ｋ／（Ｍｎ＋Ｃｅ）＝０.２５の粒子であった。ＴＧによる燃焼開始温度は３３７℃であった。
[ Reference Example 15 ]
Potassium carbonate (K 2 CO 3 ) was prepared by dissolving in water so that the solution concentration was 0.60 mol / L. The solution obtained in this way was prepared by putting the composite oxide of Mn and Ce (molar ratio: Ce / (Mn + Ce) = 0.75) prepared by the method of Reference Example 1 into a crucible and heating to 90 ° C. The 0.66 mol / L potassium carbonate aqueous solution was stirred and a liquid amount of K / (Mn + Ce) = 0.25 was gradually added dropwise. After completion of dropping, the mixture was mixed well and dried overnight in a drier set at 90 ° C. The thus obtained dried K-coated Mn—Ce composite oxide is fired in air at 450 ° C. (temperature increase rate: 300 ° C./hour) for 5 hours, thereby containing a composite of Mn and Ce containing K. An oxide was obtained.
As a result of composition analysis, the obtained catalyst powder was particles having a molar ratio of Ce / (Mn + Ce) = 0.75 and K / (Mn + Ce) = 0.25. The combustion start temperature by TG was 337 ° C.
［参考例１６〜２０］
滴下する炭酸カリウム水溶液量を変化させた以外は参考例１５と同様の操作を行なって、触媒粒子を合成した。その際の粒子の組成、燃焼特性について表１に示す。
[ Reference Examples 16 to 20 ]
Catalyst particles were synthesized in the same manner as in Reference Example 15 except that the amount of potassium carbonate aqueous solution dropped was changed. Table 1 shows the composition and combustion characteristics of the particles.
［参考例２１］
０.６０ｍｏｌ／Ｌになるよう調製した炭酸ルビジウム(Ｒｂ2ＣＯ3)(和光純薬工業株式会社製)を準備し、参考例１の方法にて作成しておいたＭｎとＣｅの複合酸化物(モル比:Ｃｅ／（Ｍｎ＋Ｃｅ）＝０.７５)におけるＭｎとＣｅの合計に対してＲｂがモル比でＲｂ／（Ｍｎ＋Ｃｅ）＝０.１５になるように添加する液量を調整した。その後、参考例１の方法にて作成しておいたＭｎ−Ｃｅの複合酸化物をるつぼに入れ、９０℃で加熱しながら、調製した炭酸ルビジウム溶液を徐々に滴下した。全て滴下した後、よく混合し９０℃の乾燥器で一晩乾燥させた。空気中４５０℃(昇温速度３００℃／時間)で５時間焼成することによって、Ｒｂを含有するＭｎとＣｅの複合酸化物を得た。
[ Reference Example 21 ]
A composite oxide of Mn and Ce prepared by the method of Reference Example 1 by preparing rubidium carbonate (Rb 2 CO 3 ) (manufactured by Wako Pure Chemical Industries, Ltd.) prepared to be 0.60 mol / L. The amount of liquid added was adjusted such that Rb was in a molar ratio of Rb / (Mn + Ce) = 0.15 with respect to the sum of Mn and Ce in (molar ratio: Ce / (Mn + Ce) = 0.75). Thereafter, the Mn—Ce composite oxide prepared by the method of Reference Example 1 was placed in a crucible, and the prepared rubidium carbonate solution was gradually added dropwise while heating at 90 ° C. After all was added dropwise, the mixture was mixed well and dried overnight in a 90 ° C. drier. The composite oxide of Mn and Ce containing Rb was obtained by firing for 5 hours at 450 ° C. (
得られた触媒粉末は組成分析の結果、モル比でＣｅ／（Ｍｎ＋Ｃｅ）＝０.７５、Ｒｂ／（Ｍｎ＋Ｃｅ）＝０.１５の粒子であった。ＢＥＴ値は１５.１７ｍ2／ｇであり、ＴＧによる燃焼開始温度は３０２℃であった。得られた粒子のＸ線回折パターンは図１に示すとおりであり、これをＪＣＰＤＳパターンに当てはめるとＭｎ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、ＭｎはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。
また、参考例２１のＴＧ曲線を図３に示す。
As a result of composition analysis, the obtained catalyst powder was particles having a molar ratio of Ce / (Mn + Ce) = 0.75 and Rb / (Mn + Ce) = 0.15. The BET value was 15.17 m 2 / g, and the combustion start temperature by TG was 302 ° C. The X-ray diffraction pattern of the obtained particles is as shown in FIG. 1. When this is applied to the JCPDS pattern, no peak derived from Mn oxide is confirmed, and only the peak of Ce oxide occupying the majority is observed. Therefore, it is presumed that Mn is in the form of a so-called solid solution incorporated in Ce.
The TG curve of Reference Example 21 is shown in FIG.
［参考例２２〜２６］
Ｍｎ−Ｃｅの複合酸化物に滴下するＲｂ水溶液量をそれぞれ表１に示した物量になるように変化させた以外は参考例２１と同様の操作を行なって触媒粒子を合成させた。その際の粒子の組成、燃焼特性について表１に示す。
[ Reference Examples 22 to 26 ]
Catalyst particles were synthesized in the same manner as in Reference Example 21 , except that the amount of the Rb aqueous solution dropped onto the Mn—Ce composite oxide was changed to the amount shown in Table 1, respectively. Table 1 shows the composition and combustion characteristics of the particles.
［参考例２７］
０.６０ｍｏｌ／Ｌになるよう調製した炭酸セシウムを準備し、参考例１の方法にて作成しておいたＭｎとＣｅの複合酸化物(モル比: Ｃｅ／（Ｍｎ＋Ｃｅ）＝０.７５)におけるＭｎとＣｅの合計に対してＣｓがモル比でＣｓ／（Ｍｎ＋Ｃｅ）＝０.３８になるよう添加する液量を調整した。その後、参考例１の方法にて作成しておいたＭｎとＣｅの複合酸化物をるつぼに入れ、９０℃で加熱・撹拌させながら、調製した炭酸セシウム溶液を徐々に滴下した。滴下終了後、よく混合し９０℃の乾燥器で一晩乾燥させた。空気中４５０℃(昇温速度３００℃／時間)で５時間焼成することによって、Ｃｓを含有するＭｎとＣｅとの複合酸化物を得た。
[ Reference Example 27 ]
Cesium carbonate prepared to 0.66 mol / L was prepared, and the composite oxide of Mn and Ce (molar ratio: Ce / (Mn + Ce) = 0.75) prepared by the method of Reference Example 1 was used. The amount of liquid added was adjusted so that Cs was in a molar ratio of Cs / (Mn + Ce) = 0.38 with respect to the total of Mn and Ce. Thereafter, the composite oxide of Mn and Ce prepared by the method of Reference Example 1 was put in a crucible, and the prepared cesium carbonate solution was gradually added dropwise while heating and stirring at 90 ° C. After completion of dropping, the mixture was mixed well and dried overnight in a 90 ° C. drier. The composite oxide of Mn and Ce containing Cs was obtained by firing in air at 450 ° C. (
得られた複合酸化物は組成分析の結果、モル比でＣｅ／（Ｍｎ＋Ｃｅ）＝０.７５、Ｃｓ／（Ｍｎ＋Ｃｅ）＝０.３８の粒子であった。ＴＧによる燃焼開始温度は２９６℃であった。得られた粒子のＸ線回折パターンは図１に示すとおりであり、これをＪＣＰＤＳパターンに当てはめるとＭｎ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、複合酸化物においてＭｎはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。
また、参考例２７のＴＧ曲線を図３に示す。
As a result of composition analysis, the obtained composite oxide was particles having a molar ratio of Ce / (Mn + Ce) = 0.75 and Cs / (Mn + Ce) = 0.38. The combustion start temperature by TG was 296 ° C. The X-ray diffraction pattern of the obtained particles is as shown in FIG. 1. When this is applied to the JCPDS pattern, no peak derived from Mn oxide is confirmed, and only the peak of Ce oxide occupying the majority is observed. Therefore, it is presumed that in the composite oxide, Mn is in the form of a so-called solid solution taken into Ce.
The TG curve of Reference Example 27 is shown in FIG.
［参考例２８〜２９］
Ｍｎ−Ｃｅの複合酸化物に滴下するＣｓ水溶液量をそれぞれ表１に示した物量になるように変化させた以外は参考例２７と同様の操作を行なって触媒粒子を合成させた。その際の粒子の組成、燃焼特性について表１に示す。
[ Reference Examples 28 to 29 ]
Catalyst particles were synthesized in the same manner as in Reference Example 27 except that the amount of the Cs aqueous solution dropped onto the composite oxide of Mn—Ce was changed to the amount shown in Table 1, respectively. Table 1 shows the composition and combustion characteristics of the particles.
［実施例１〜２］
０.６０ｍｏｌ／Ｌになるよう調製した炭酸ルビジウムを準備し、参考例６の方法にて作成しておいたＦｅとＣｅの複合酸化物(モル比: Ｃｅ／（Ｆｅ＋Ｃｅ）＝０.９５)におけるＦｅとＣｅの合計に対してＲｂがモル比でＲｂ／（Ｆｅ＋Ｃｅ）＝０.１７、０.３４になるよう添加する液量を調整した。その後、参考例６の方法にて作成しておいたＦｅとＣｅの複合酸化物をるつぼに入れ、９０℃で加熱・撹拌させながら、調製した炭酸ルビジウム溶液を徐々に滴下した。滴下終了後、よく混合し９０℃の乾燥器で一晩乾燥させた。空気中４５０℃(昇温速度３００℃／時間)で５時間焼成することによって、Ｒｂを含有するＦｅとＣｅとの複合酸化物を得た。
実施例２で得られたＲｂ／（Ｆｅ＋Ｃｅ）＝０.３４の粒子は、図２に示すＸ線回折パターンを有しており、これをＪＣＰＤＳパターンに当てはめるとＦｅ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、複合酸化物においてＦｅはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。実施例２で得られた物質の燃焼状態を示すＴＧ曲線を図４に示した。
[ Examples 1-2 ]
In the composite oxide of Fe and Ce (molar ratio: Ce / (Fe + Ce) = 0.95) prepared by the method of Reference Example 6 , rubidium carbonate prepared to 0.66 mol / L was prepared. The amount of liquid added was adjusted so that Rb was in a molar ratio of Rb / (Fe + Ce) = 0.17, 0.34 with respect to the total of Fe and Ce. Thereafter, the composite oxide of Fe and Ce prepared by the method of Reference Example 6 was placed in a crucible, and the prepared rubidium carbonate solution was gradually added dropwise while heating and stirring at 90 ° C. After completion of dropping, the mixture was mixed well and dried overnight in a 90 ° C. drier. The composite oxide of Fe and Ce containing Rb was obtained by firing for 5 hours at 450 ° C. (temperature increase rate: 300 ° C./hour) in the air.
The particles of Rb / (Fe + Ce) = 0.34 obtained in Example 2 have the X-ray diffraction pattern shown in FIG. 2, and when this is applied to the JCPDS pattern, a peak derived from Fe oxide is confirmed. However, since only the peak of Ce oxide occupying the majority was observed, it is presumed that in the composite oxide, Fe is in the form of a so-called solid solution taken into Ce. A TG curve showing the combustion state of the substance obtained in Example 2 is shown in FIG.
［実施例３］
０.６０ｍｏｌ／Ｌになるよう調製した炭酸セシウムを準備し、参考例６の方法にて作成しておいたＦｅとＣｅの複合酸化物(モル比: Ｃｅ／（Ｆｅ＋Ｃｅ）＝０.９５)におけるＦｅとＣｅの合計に対してＣｓがモル比でＣｓ／（Ｆｅ＋Ｃｅ）＝０.３３になるよう添加する液量を調整した。その後、参考例６の方法にて作成しておいたＦｅとＣｅの複合酸化物をるつぼに入れ、９０℃で加熱・撹拌させながら、調製した炭酸セシウム溶液を徐々に滴下した。滴下終了後、よく混合し９０℃の乾燥器で一晩乾燥させた。空気中４５０℃(昇温速度３００℃／時間)で５時間焼成することによって、Ｃｓを含有するＦｅとＣｅとの複合酸化物を得た。その際の粒子の組成、燃焼特性について表１に示す。
[ Example 3 ]
Cesium carbonate prepared to 0.66 mol / L was prepared, and the composite oxide of Fe and Ce (molar ratio: Ce / (Fe + Ce) = 0.95) prepared by the method of Reference Example 6 was used. The amount of liquid added was adjusted so that Cs was in a molar ratio of Cs / (Fe + Ce) = 0.33 with respect to the total of Fe and Ce. Thereafter, the composite oxide of Fe and Ce prepared by the method of Reference Example 6 was put in a crucible, and the prepared cesium carbonate solution was gradually added dropwise while heating and stirring at 90 ° C. After completion of dropping, the mixture was mixed well and dried overnight in a 90 ° C. drier. The composite oxide of Fe and Ce containing Cs was obtained by firing in air at 450 ° C. (
［実施例４］
Ｆｅ−Ｃｅの複合酸化物に滴下するＣｓ水溶液量を表１に示した物量になるように変化させた以外は実施例３と同様の操作を行なって触媒粒子を合成させた。その際の粒子の組成、燃焼特性について表１に示す。
[ Example 4 ]
Catalyst particles were synthesized in the same manner as in Example 3 except that the amount of the Cs aqueous solution dropped onto the composite oxide of Fe—Ce was changed to the amount shown in Table 1. Table 1 shows the composition and combustion characteristics of the particles.
得られた複合酸化物は組成分析の結果、モル比でＣｅ／（Ｆｅ＋Ｃｅ）＝０.９５、Ｃｓ／（Ｆｅ＋Ｃｅ）＝０.４９の粒子であった。ＴＧによる燃焼開始温度は３２３℃であった。得られた粒子のＸ線回折パターンは図２に示すとおりであり、これをＪＣＰＤＳパターンに当てはめるとＦｅ酸化物に由来するピークは確認されず、大部分を占めるＣｅ酸化物のピークのみが観察されたので、複合酸化物においてＦｅはＣｅの中に取り込まれた、いわゆる固溶体の形態をしているものと推測される。
また、実施例４のＴＧ曲線を図４に示す。
As a result of the composition analysis, the obtained composite oxide was particles having a molar ratio of Ce / (Fe + Ce) = 0.95 and Cs / (Fe + Ce) = 0.49. The combustion start temperature by TG was 323 ° C. The X-ray diffraction pattern of the obtained particles is as shown in FIG. 2, and when this is applied to the JCPDS pattern, the peak derived from Fe oxide is not confirmed, and only the peak of Ce oxide occupying the majority is observed. Therefore, it is presumed that in the composite oxide, Fe is in the form of a so-called solid solution taken into Ce.
Moreover, the TG curve of Example 4 is shown in FIG.
［比較例１］
カーボンブラックのみの燃焼開始温度測定を行うと、表２に示すように６２４℃であった。
[Comparative Example 1]
When the combustion start temperature of only carbon black was measured, it was 624 ° C. as shown in Table 2.
［比較例２〜４］
触媒粒子として、それぞれＭｎ2Ｏ3、ＣｅＯ2、Ｆｅ2Ｏ3を使用して（これら酸化物の作成方法は、相対する元素を添加しなかった以外は参考例１、参考例６と同様である。）、燃焼開始温度測定を行った。燃焼開始温度はＭｎ2Ｏ3の場合（比較例２）が４２６℃、ＣｅＯ2の場合（比較例３）が４４４℃、Ｆｅ2Ｏ3の場合（比較例４）が４６９℃であった。比較例２と比較例３の両比較例のＴＧ曲線を図３に示し、比較例２（破線）と比較例４（実線）の両比較例のＴＧ曲線
を図４に示す。
[Comparative Examples 2 to 4]
As catalyst particles, Mn 2 O 3 , CeO 2 , and Fe 2 O 3 were used, respectively. (The preparation method of these oxides was the same as in Reference Example 1 and Reference Example 6 except that the corresponding elements were not added. There was a combustion start temperature measurement. The combustion start temperature was 426 ° C. for Mn 2 O 3 (Comparative Example 2), 444 ° C. for CeO 2 (Comparative Example 3), and 469 ° C. for Fe 2 O 3 (Comparative Example 4). FIG. 3 shows the TG curves of both Comparative Examples 2 and 3, and FIG. 4 shows the TG curves of both Comparative Examples 2 (broken line) and Comparative Example 4 (solid line).
［比較例５］
複合酸化物においてＣｅ／（Ｍｎ＋Ｃｅ）＝０.１０に変化させた以外は参考例１と同様にして、触媒粒子を調製し、燃焼開始温度測定を行った。燃焼開始温度は４１２℃であった。
[Comparative Example 5]
Catalyst particles were prepared in the same manner as in Reference Example 1 except that the complex oxide was changed to Ce / (Mn + Ce) = 0.10, and the combustion start temperature was measured. The combustion start temperature was 412 ° C.
［比較例６］
複合酸化物においてＣｅ／（Ｆｅ＋Ｃｅ）＝０.５０に変化させた以外は参考例６と同様にして、触媒粒子を調製し、燃焼開始温度測定を行った。燃焼開始温度は４０１℃であった。
[Comparative Example 6]
Catalyst particles were prepared in the same manner as in Reference Example 6 except that the complex oxide was changed to Ce / (Fe + Ce) = 0.50, and the combustion start temperature was measured. The combustion start temperature was 401 ° C.
［比較例７〜９］
ＭｎとＣｅの複合酸化物試料の調製と同様の手順でＭｎ−Ｐｒを調製した。すなわち参考例のＣｅ原料の代わりにＰｒ原料として硝酸プラセオジム(III)６水和物(純度９９.９％、キシダ化学株式会社製)を使用した。Ｐｒ／Ｍｎのモル比をそれぞれ表２のとおり変化させた粒子を作成してそれぞれ燃焼開始温度測定を行った。燃焼開始温度を表２に示す。
[Comparative Examples 7 to 9]
Mn-Pr was prepared by the same procedure as that for preparing a composite oxide sample of Mn and Ce. That is, praseodymium (III) nitrate hexahydrate (purity 99.9%, manufactured by Kishida Chemical Co., Ltd.) was used as the Pr raw material instead of the Ce raw material of the reference example . Particles in which the Pr / Mn molar ratio was changed as shown in Table 2 were prepared, and the combustion start temperature was measured. Table 2 shows the combustion start temperature.
参考例と比較例７〜９の比較において、遷移金属とＣｅの複合酸化物と遷移金属とＰｒの複合酸化物の比較を行ったときの触媒活性の違いがわかる。この結果より、Ｃｅと遷移金属の複合酸化物を形成させたときの方が、同様にランタノイド元素であるＰｒを使用した場合に比較してより高い触媒活性を有していることがわかる。 In the comparison between the reference example and Comparative Examples 7 to 9, the difference in catalytic activity is found when the transition metal / Ce composite oxide and the transition metal / Pr composite oxide are compared. From this result, it can be seen that when a complex oxide of Ce and a transition metal is formed, the catalyst activity is higher than that in the case of using Pr which is a lanthanoid element.
参考例１と参考例１５以降の比較によって、粒子に対する添加元素の効果がわかる。つまり、Ｋ、ＲｂまたはＣｓが存在しているとカーボン燃焼開始温度の低下効果がより一層高まる可能性が示唆される結果が得られ、特に、参考例２１以降に示したＲｂ、Ｃｓを選択することによって燃焼開始温度の低減効果がより高まることがわかる。 A comparison between Reference Example 1 and Reference Example 15 and later shows the effect of the additive element on the particles. That is, when K, Rb, or Cs is present, a result suggesting that the effect of lowering the carbon combustion start temperature may be further increased. In particular, Rb and Cs shown in Reference Example 21 and later are selected. It can be seen that the effect of reducing the combustion start temperature is further increased.
参考例１〜５あるいは参考例６〜１１と比較例２〜４の対比から、Ｍｎ、Ｃｅ、Ｆｅの各酸化物（Ｍｎ2Ｏ3、Ｆｅ2Ｏ3、ＣｅＯ2）成分は単独で存在してもどの成分も存在しない比較例１に比べて燃焼開始温度は低下するが、これら成分が複合化することによって、さらにその効果を増すことが可能であることが示される。さらには、ＸＲＤパターンにおいて、Ｍｎ2Ｏ3あるいはＦｅ2Ｏ3のピークが現れず、複合酸化物においてＣｅにＭｎが固溶した状態にあると見られる場合の方が、その効果は顕著となる可能性が高いことが示唆される。 From the comparison between Reference Examples 1 to 5 or Reference Examples 6 to 11 and Comparative Examples 2 to 4, each oxide of Mn, Ce, and Fe (Mn 2 O 3 , Fe 2 O 3 , CeO 2 ) is present alone. However, although the combustion start temperature is lower than that of Comparative Example 1 in which no component is present, it is shown that the effect can be further increased by combining these components. Further, in the XRD pattern, the Mn 2 O 3 or Fe 2 O 3 peak does not appear, and the effect is more remarkable when it is considered that Mn is in a solid solution state in Ce in the composite oxide. It is suggested that the possibility is high.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006067915A JP5119508B2 (en) | 2005-11-21 | 2006-03-13 | PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005336408 | 2005-11-21 | ||
| JP2005336408 | 2005-11-21 | ||
| JP2006067915A JP5119508B2 (en) | 2005-11-21 | 2006-03-13 | PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007160297A JP2007160297A (en) | 2007-06-28 |
| JP5119508B2 true JP5119508B2 (en) | 2013-01-16 |
Family
ID=38243795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006067915A Expired - Fee Related JP5119508B2 (en) | 2005-11-21 | 2006-03-13 | PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5119508B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4904458B2 (en) * | 2006-02-07 | 2012-03-28 | Ｄｏｗａエレクトロニクス株式会社 | Composite oxide and filter for PM combustion catalyst |
| EP1920831B1 (en) * | 2006-11-08 | 2020-06-03 | Nissan Motor Co., Ltd. | Compound oxide-based particulate matter oxidizing catalyst |
| JP5057462B2 (en) * | 2007-12-26 | 2012-10-24 | 本田技研工業株式会社 | Exhaust gas purification catalyst |
| JP5441380B2 (en) * | 2008-09-19 | 2014-03-12 | 株式会社日本触媒 | Formaldehyde oxidation catalyst and method for producing the same |
| JP2010131531A (en) * | 2008-12-05 | 2010-06-17 | Nippon Shokubai Co Ltd | Air cleaning catalyst and its manufacturing method |
| JP5287358B2 (en) * | 2009-03-03 | 2013-09-11 | 日産自動車株式会社 | Oxidation catalyst |
| JP5708767B1 (en) * | 2013-11-22 | 2015-04-30 | トヨタ自動車株式会社 | Exhaust gas purification catalyst and method for producing the same |
| JP2017144423A (en) * | 2016-02-17 | 2017-08-24 | トヨタ自動車株式会社 | Catalyst for exhaust purification and method for producing the same |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1131198A (en) * | 1979-02-01 | 1982-09-07 | Carus Corporation | Rare earth-manganese oxidation catalysts and process of producing |
| JPH067920B2 (en) * | 1987-03-31 | 1994-02-02 | 株式会社リケン | Exhaust gas purification material and exhaust gas purification method |
| JP2863571B2 (en) * | 1989-10-03 | 1999-03-03 | 株式会社リケン | Exhaust gas purifying material and exhaust gas purifying method |
| JPH0440235A (en) * | 1990-06-04 | 1992-02-10 | Riken Corp | Exhaust gas purifying material and method |
| JPH0440236A (en) * | 1990-06-04 | 1992-02-10 | Riken Corp | Exhaust gas purifying material and method |
| JPH0440237A (en) * | 1990-06-04 | 1992-02-10 | Riken Corp | Exhaust gas purifying material and method |
| JPH0531330A (en) * | 1991-07-31 | 1993-02-09 | Riken Corp | Decontamination of exhaust gas |
| JPH09271665A (en) * | 1996-04-04 | 1997-10-21 | Nippon Soken Inc | Exhaust gas purifying catalyst |
| US5977017A (en) * | 1996-04-10 | 1999-11-02 | Catalytic Solutions, Inc. | Perovskite-type metal oxide compounds |
| JPH10151348A (en) * | 1996-11-22 | 1998-06-09 | Toyota Central Res & Dev Lab Inc | Oxidation catalyst |
| JP2002186856A (en) * | 2000-12-21 | 2002-07-02 | Nippon Mitsubishi Oil Corp | Diesel exhaust gas cleaning catalyst |
| JP3940794B2 (en) * | 2002-11-08 | 2007-07-04 | 独立行政法人産業技術総合研究所 | Catalyst for burning hydrocarbons in exhaust gas and method for burning hydrocarbons in exhaust gas |
| JP4776869B2 (en) * | 2003-01-16 | 2011-09-21 | パナソニック株式会社 | Exhaust gas purification catalyst, exhaust gas purification material using the same, and method for producing the same |
| JP4679583B2 (en) * | 2004-10-14 | 2011-04-27 | 田中貴金属工業株式会社 | Platinum group metal-free catalyst for filtering particulates on diesel particulate filters |
-
2006
- 2006-03-13 JP JP2006067915A patent/JP5119508B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007160297A (en) | 2007-06-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5119508B2 (en) | PM combustion oxidation catalyst, diesel engine exhaust gas purification method, filter and purification apparatus using the same | |
| JP5698908B2 (en) | Exhaust gas purification catalyst | |
| JP5864443B2 (en) | Exhaust gas purification catalyst | |
| JP5190196B2 (en) | Composite oxide for exhaust gas purification catalyst, exhaust gas purification catalyst, and diesel exhaust gas purification filter | |
| JP2005066559A (en) | Exhaust gas treatment catalyst and exhaust gas treatment method | |
| JP5063980B2 (en) | Composite oxide and filter for exhaust gas purification catalyst | |
| JPWO2014103597A1 (en) | Exhaust gas purification catalyst composition and exhaust gas purification catalyst | |
| WO2007113981A1 (en) | Catalyst composition | |
| JP2011045840A (en) | Catalyst composition | |
| JP4904458B2 (en) | Composite oxide and filter for PM combustion catalyst | |
| CN109689205A (en) | Purposes of the vanadate as oxidation catalyst | |
| JP6145763B2 (en) | Particulate matter combustion catalyst and particulate matter combustion catalyst filter | |
| JP4768475B2 (en) | Composite oxide and filter for PM combustion catalyst | |
| JP5101346B2 (en) | Exhaust gas purification catalyst and method for producing the same | |
| JP2008284512A (en) | Oxygen absorbing-releasing material and exhaust gas purifying catalyst containing the same | |
| JP5585805B2 (en) | PM oxidation catalyst and production method thereof | |
| JP5387318B2 (en) | Particulate combustion catalyst and particulate combustion removal method using the same | |
| JP5973914B2 (en) | Method for producing catalyst composition for exhaust gas treatment | |
| WO2018055894A1 (en) | Particulate matter combustion catalyst and particulate matter combustion catalyst filter | |
| JP5541843B2 (en) | Composite oxide for exhaust gas purification catalyst and exhaust gas purification filter using the same | |
| JP2019136632A (en) | Combustion catalyst | |
| JPWO2009044736A1 (en) | Cerium-containing composite oxide and method for producing the same, PM combustion catalyst, and diesel particulate filter | |
| JP6549858B2 (en) | Exhaust gas purification three-way catalyst | |
| JP2000051698A (en) | Exhaust emission purifying catalyst and its use | |
| JP2020033246A (en) | Delaffosite oxides and production method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20090202 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20101209 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110208 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110407 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120117 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120314 |
|
| 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: 20120925 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20121003 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20121003 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20121003 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20151102 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
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 |
|
| LAPS | Cancellation because of no payment of annual fees |