JP5233026B2 - Manufacturing method of DPF - Google Patents
Manufacturing method of DPF Download PDFInfo
- Publication number
- JP5233026B2 JP5233026B2 JP2006059226A JP2006059226A JP5233026B2 JP 5233026 B2 JP5233026 B2 JP 5233026B2 JP 2006059226 A JP2006059226 A JP 2006059226A JP 2006059226 A JP2006059226 A JP 2006059226A JP 5233026 B2 JP5233026 B2 JP 5233026B2
- Authority
- JP
- Japan
- Prior art keywords
- complex oxide
- dpf
- porous body
- precursor
- exhaust gas
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 17
- 239000011148 porous material Substances 0.000 claims description 38
- 239000002243 precursor Substances 0.000 claims description 38
- 239000002002 slurry Substances 0.000 claims description 22
- 238000010304 firing Methods 0.000 claims description 15
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 8
- 229910052784 alkaline earth metal Inorganic materials 0.000 claims description 6
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 229910052788 barium Inorganic materials 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 229910052746 lanthanum Inorganic materials 0.000 claims description 4
- 150000001342 alkaline earth metals Chemical class 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 230000002194 synthesizing effect Effects 0.000 claims description 3
- 229910052723 transition metal Inorganic materials 0.000 claims description 3
- 230000007704 transition Effects 0.000 claims 1
- 239000013618 particulate matter Substances 0.000 description 53
- 239000007789 gas Substances 0.000 description 50
- 239000003054 catalyst Substances 0.000 description 34
- 238000000034 method Methods 0.000 description 34
- 238000002485 combustion reaction Methods 0.000 description 25
- 150000003839 salts Chemical class 0.000 description 18
- 229910000510 noble metal Inorganic materials 0.000 description 14
- 239000007864 aqueous solution Substances 0.000 description 13
- 230000007423 decrease Effects 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- 239000002244 precipitate Substances 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 150000004703 alkoxides Chemical class 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 9
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 9
- 239000002245 particle Substances 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 230000003197 catalytic effect Effects 0.000 description 8
- 239000003795 chemical substances by application Substances 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- 239000012298 atmosphere Substances 0.000 description 7
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- 239000002131 composite material Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000010410 layer Substances 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 238000000967 suction filtration Methods 0.000 description 6
- 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 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000000975 co-precipitation Methods 0.000 description 5
- 238000004453 electron probe microanalysis Methods 0.000 description 5
- 238000002474 experimental method Methods 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 5
- 230000001376 precipitating effect Effects 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000003472 neutralizing effect Effects 0.000 description 4
- 239000002344 surface layer Substances 0.000 description 4
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- ZMANZCXQSJIPKH-UHFFFAOYSA-N Triethylamine Chemical compound CCN(CC)CC ZMANZCXQSJIPKH-UHFFFAOYSA-N 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 239000001099 ammonium carbonate Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- -1 organic acid salts Chemical class 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052763 palladium Inorganic materials 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 235000012501 ammonium carbonate Nutrition 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- 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 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000010970 precious metal Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 description 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 229910052692 Dysprosium Inorganic materials 0.000 description 1
- 238000005033 Fourier transform infrared spectroscopy Methods 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- APLQTTYBCHJFIJ-UHFFFAOYSA-N [Ba].[N+](=O)(O)[O-] Chemical compound [Ba].[N+](=O)(O)[O-] APLQTTYBCHJFIJ-UHFFFAOYSA-N 0.000 description 1
- 150000001242 acetic acid derivatives Chemical class 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 238000007084 catalytic combustion reaction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 150000007529 inorganic bases Chemical class 0.000 description 1
- LITYQKYYGUGQLY-UHFFFAOYSA-N iron nitric acid Chemical compound [Fe].O[N+]([O-])=O LITYQKYYGUGQLY-UHFFFAOYSA-N 0.000 description 1
- XQBXQQNSKADUDV-UHFFFAOYSA-N lanthanum;nitric acid Chemical compound [La].O[N+]([O-])=O XQBXQQNSKADUDV-UHFFFAOYSA-N 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
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000001630 malic acid Substances 0.000 description 1
- 235000011090 malic acid Nutrition 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000007530 organic bases Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 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
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 239000010948 rhodium Substances 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 229910052712 strontium Inorganic materials 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229910001936 tantalum oxide Inorganic materials 0.000 description 1
- UEUXEKPTXMALOB-UHFFFAOYSA-J tetrasodium;2-[2-[bis(carboxylatomethyl)amino]ethyl-(carboxylatomethyl)amino]acetate Chemical compound [Na+].[Na+].[Na+].[Na+].[O-]C(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O UEUXEKPTXMALOB-UHFFFAOYSA-J 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
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
Description
本発明は、ディーゼルエンジンの排気ガス中に含まれるＰＭ（粒子状物質）を捕集する機能を有するとともに、捕集したＰＭを燃焼させるための触媒を備えたＤＰＦ（ディーゼル・パティキュレート・フィルター）、およびその製造法に関する。 The present invention has a function of collecting PM (particulate matter) contained in exhaust gas of a diesel engine and a DPF (diesel particulate filter) provided with a catalyst for burning the collected PM. , And its manufacturing method.
ディーゼルエンジンの排ガスに関しては、特に窒素酸化物（ＮＯX）とＰＭが問題となっている。このうちＰＭはカーボンを主体とする微粒子であり、その除去方法として排気ガス流路にＤＰＦを設置してＰＭを捕集する方法が一般化されつつある。捕集されたＰＭは間欠的または連続的に燃焼され、当該ＤＰＦは再生される。 Nitrogen oxides (NO x ) and PM are particularly problematic with regard to exhaust gas from diesel engines. Among these, PM is fine particles mainly composed of carbon, and as a method for removing the particulate matter, a method of collecting PM by installing a DPF in an exhaust gas flow path is being generalized. The collected PM is burned intermittently or continuously, and the DPF is regenerated.
このフィルター再生処理には、電気ヒーターやバーナー等を用いてＰＭを燃焼させる方法や、ＤＰＦに触媒を担持し、その触媒作用によりＰＭの燃焼開始温度を低下させ、排ガスの熱を利用して連続的または間欠的に燃焼させる方法などがある。前者はシステムが複雑化することから、後者の触媒方式が望ましいとされている。 For this filter regeneration treatment, a method of burning PM using an electric heater, a burner or the like, or a catalyst is supported on a DPF, and the catalytic combustion lowers the combustion start temperature of PM and continuously uses the heat of exhaust gas. There is a method of burning automatically or intermittently. Since the former complicates the system, the latter catalytic method is desirable.
この触媒方式に関し、従来から種々の技術が提案されている。
例えば、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も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させること（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。
Various techniques have been proposed for this catalyst system.
For example, lowering the combustion start temperature by forming a platinum group and alkaline earth metal on the surface of the catalyst (Patent Document 1), and using a catalyst component containing a noble metal and an oxygen storage component (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 4), nitrogen monoxide and oxygen in exhaust gas And a mechanism for burning the PM component using nitrogen dioxide generated there after selective reaction (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）などが挙げられる。
さらには、フィルタに触媒成分を含浸させた後に、フィルタを加熱して触媒物質を生成・担持させる技術についても提案されている（特許文献９、１０）。
Further, as a catalyst having an effect of assisting PM combustion, a catalyst that passes over a catalytically active material such as lithium oxide (Patent Document 6), and a catalyst that uses oxides of V and W and palladium as catalyst components (patent) Reference 7) and those using a perovskite complex oxide as an oxidation catalyst (Patent Document 8).
Furthermore, a technique has been proposed in which a filter material is impregnated with a catalyst component and then the filter is heated to generate and support a catalyst substance (Patent Documents 9 and 10).
特許文献１〜８の技術によって得られる触媒粒子をＤＰＦにコーティングするには、通常、「ウオッシュコート法」が採用される。この方法は、アルミナゾルなどに触媒およびその担体を混合した上で、直接塗布し、その後乾燥・焼成など行うものである。しかし、ゾルなどへの分散性などを考慮して、添加物の種類やその物性などを調整する必要もあるので、必ずしも簡便な方法であるとは言えない。また、フィルタ層と触媒担持層が二重の層構造を有しており、排ガスを通気させる際に圧力損失（圧損）が大きくなりやすい。 In order to coat the catalyst particles obtained by the techniques of Patent Documents 1 to 8 on the DPF, a “wash coat method” is usually employed. In this method, an alumina sol or the like is mixed with a catalyst and its carrier, and then directly applied, followed by drying and firing. However, it is not always a simple method because it is necessary to adjust the kind of additive and its physical properties in consideration of dispersibility in sol and the like. Further, since the filter layer and the catalyst support layer have a double layer structure, pressure loss (pressure loss) tends to increase when the exhaust gas is ventilated.
これに対し、特許文献９、１０に開示の技術は、触媒成分の水溶液をフィルタに直接含浸させ、その後焼成により貴金属を含むペロブスカイト複合酸化物をフィルタに担持させるものである。この方法だと比較的簡便に触媒物質の付着したフィルタを作製することができ、前記の二重層による圧損も軽減でき、またフィルタの内部まで十分に触媒成分が行き渡ることにより、有害成分の無害化には効果的であると考えられた。 On the other hand, the techniques disclosed in Patent Documents 9 and 10 directly impregnate a filter with an aqueous solution of a catalyst component, and then support the perovskite complex oxide containing a noble metal by firing. With this method, it is possible to produce a filter with a catalyst substance attached relatively easily, reducing the pressure loss due to the double layer, and making the harmful components harmless by sufficiently spreading the catalyst components to the inside of the filter. It was considered effective.
しかしながら、発明者らの調査によれば、このような原料液をフィルタに含浸させて得たＤＰＦでは、触媒活性が必ずしも期待通りに発揮されないことがわかった。例えば、本来、ＰＭ燃焼触媒として優れた活性を示すペロブスカイト型複合酸化物をこの手法に適用しても、ＰＭ燃焼温度があまり十分に低下しない。その原因の１つとして、ＰＭは有限の大きさを有する粒子であることから、フィルタの内部にまで行き渡る前に濾しとられてしまうことが考えられる。すなわち、多孔体フィルタの排気ガス入り側よりかなり奥深くに存在する触媒物質は、ＰＭの燃焼にあまり寄与しないのではないかと推察される。 However, according to investigations by the inventors, it has been found that DPF obtained by impregnating such a raw material liquid into a filter does not necessarily exhibit catalytic activity as expected. For example, even when a perovskite type complex oxide, which originally exhibits excellent activity as a PM combustion catalyst, is applied to this technique, the PM combustion temperature does not decrease sufficiently. One of the causes is that PM is a particle having a finite size, and is thus filtered before reaching the inside of the filter. That is, it is presumed that the catalyst substance existing considerably deeper than the exhaust gas inlet side of the porous filter may not contribute much to the combustion of PM.
そこで本発明は、圧損の低下が少なく、ＰＭ燃焼温度を安定して低減でき、かつ、簡便な方法で作製できるＤＰＦを提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a DPF that can be manufactured by a simple method that can reduce the PM combustion temperature stably with little decrease in pressure loss.
上記目的は、ＰＭを捕集する多孔体の細孔壁にペロブスカイト型複合酸化物が担持されており、ペロブスカイト型複合酸化物の存在量が、「当該多孔体の排気ガス入り側表面上」、「排気ガス入り側表面からの深さが４０〜１２０μｍ位置の細孔壁面上」、「排気ガス入り側表面からの深さが１４０μｍ以上の位置の細孔壁面上」の順に次第に減少しているＤＰＦによって達成される。 The above object is that the perovskite type composite oxide is supported on the pore walls of the porous body that collects PM, and the amount of the perovskite type composite oxide is “on the exhaust gas containing side surface of the porous body”, It gradually decreases in the order of “on the pore wall surface where the depth from the exhaust gas containing surface is 40 to 120 μm” and “on the pore wall surface where the depth from the exhaust gas containing surface is 140 μm or more”. Achieved by DPF.
ここで、上記各位置におけるペロブスカイト型複合酸化物の存在量は、多孔体の排気ガス通過方向に平行な断面について、ＥＤＳ、ＥＰＭＡなどの分析手段でペロブスカイト型複合酸化物の構成元素の検出量（ｃｐｓ）を調べることによって判断できる。被測定元素としては例えば希土類元素やアルカリ土類金属を選択することができる。 Here, the abundance of the perovskite complex oxide at each of the above positions is the detected amount of the constituent elements of the perovskite complex oxide by an analysis means such as EDS or EPMA on the cross section parallel to the exhaust gas passage direction of the porous body cps). As the element to be measured, for example, a rare earth element or an alkaline earth metal can be selected.
細孔壁面上の元素の存在量は、当該深さ位置でペロブスカイト型複合酸化物の存在が確認される箇所のうち、視野内で最も存在量が多い部分を選択して測定することができる。測定精度を上げるには複数の視野について測定して、その平均値を採用すればよい。４０〜１２０μｍの深さ位置にはペロブスカイト型複合酸化物が検出されることが必要である。この範囲の深さ位置でペロブスカイト型複合酸化物が検出できないものは、当該触媒物質が多孔体の表層付近のみに偏って存在しているものであり、好適なものとは言えない。これに対し、１４０μｍ以上の深さ位置ではペロブスカイト型複合酸化物の存在が検出される必要はなく、検出量がゼロであってもかまわない。 The abundance of the element on the pore wall surface can be measured by selecting the portion having the largest abundance in the field of view from the location where the presence of the perovskite complex oxide is confirmed at the depth position. In order to increase the measurement accuracy, it is only necessary to measure a plurality of fields of view and adopt the average value. It is necessary to detect the perovskite complex oxide at a depth of 40 to 120 μm. When the perovskite type complex oxide cannot be detected at a depth in this range, the catalyst substance is present only in the vicinity of the surface layer of the porous body, which is not preferable. On the other hand, it is not necessary to detect the presence of the perovskite complex oxide at a depth of 140 μm or more, and the detection amount may be zero.
前記ペロブスカイト型複合酸化物としては、組成式ＡＭＯ3、ただしＡサイトは１種以上の希土類元素（Ｙも希土類元素として扱う）と１種以上のアルカリ土類金属元素、Ｍサイトは１種以上の遷移金属元素、で表されるものが好適な対象となる。また、多孔体の細孔壁にはさらに貴金属元素が存在していても構わない。 The perovskite complex oxide has a composition formula AMO 3 , where the A site is one or more rare earth elements (Y is also treated as a rare earth element) and one or more alkaline earth metal elements, and the M site is one or more kinds. Those represented by transition metal elements are suitable targets. Further, a noble metal element may further exist on the pore wall of the porous body.
このようなＤＰＦの製造法として、ペロブスカイト型複合酸化物を合成するための非晶質物質である前駆体が懸濁したスラリーを、ＰＭを捕集するための多孔体の細孔中に、その排気ガス入り側表面から吸引濾過の原理で導入することにより、上記前駆体を該多孔体の細孔中に存在させ、その後、細孔中の前駆体を焼成することによりペロブスカイト型複合酸化物を多孔体の細孔壁に担持させるＤＰＦの製造法が提供される。 As a method for producing such a DPF, a slurry in which a precursor, which is an amorphous substance for synthesizing a perovskite complex oxide, is suspended in a pore of a porous body for collecting PM. By introducing the precursor from the surface containing the exhaust gas by the principle of suction filtration, the precursor is made to exist in the pores of the porous body, and then the precursor in the pores is baked to obtain the perovskite complex oxide. A method for producing a DPF supported on the pore walls of a porous body is provided.
前駆体は目的とするペロブスカイト型複合酸化物を構成する金属イオンが溶解した溶液を沈殿処理等することによって得られた中間物質であり、焼成によってペロブスカイト型複合酸化物が合成されるものである。 The precursor is an intermediate substance obtained by, for example, precipitating a solution in which metal ions constituting the target perovskite complex oxide are dissolved, and the perovskite complex oxide is synthesized by firing.
本発明によれば、予め焼成して合成された触媒物質を多孔体フィルタに塗布する従来のＤＰＦの製造に比べ、ゲルへの分散性の改善のために必要であった解砕処理や、ゲル化のための成分調整が不要となり、より簡便な工程でＤＰＦを提供することが可能になった。また、そのような従来の製造法で得られたＤＰＦのように、多孔体フィルタの表層に触媒層を設ける二重層構造をとる必要がなく、排気ガスの圧損も低減された。さらに、ＰＭが多くトラップされる多孔体の排気ガス入り側付近の細孔壁にペロブスカイト型複合酸化物触媒を高濃度に担持させ、ＰＭのトラップ量が少なくなる多孔体の内部にいくに従って当該触媒の存在量が少なくなるようにしたことにより、触媒活性がより効果的に発揮され、ＰＭ燃焼開始温度の低下が実現された。 According to the present invention, compared to the conventional production of DPF in which a catalyst material synthesized by firing in advance is applied to a porous filter, the disintegration treatment or gel required for improving dispersibility in the gel Adjustment of the component for conversion is unnecessary, and it is possible to provide the DPF by a simpler process. Further, unlike the DPF obtained by such a conventional manufacturing method, it is not necessary to adopt a double layer structure in which a catalyst layer is provided on the surface layer of the porous filter, and the pressure loss of the exhaust gas is reduced. Further, a perovskite-type composite oxide catalyst is supported at a high concentration on the pore wall near the exhaust gas entrance side of the porous body in which a large amount of PM is trapped, and the catalyst moves toward the inside of the porous body where the trap amount of PM decreases. As a result, the catalytic activity was more effectively exhibited and the PM combustion start temperature was lowered.
本発明のＤＰＦは、ＰＭを捕集する多孔体の細孔壁に直接、ペロブスカイト型複合酸化物の触媒物質を担持させたものであり、特に、その多孔体の厚さ方向において、排気ガス入り側から出側に向かってペロブスカイト型複合酸化物の存在量が少なくなっている構造に特徴を有するものである。ＰＭは排気ガスの流れに伴って多孔体フィルタの細孔に入り、トラップされるが、排気ガス中のＰＭ濃度が高い位置ほど、多孔体フィルタの細孔壁に付着する量も多くなると考えられる。すなわち、多孔体フィルタの排気ガス入り側近傍ではガス中のＰＭ濃度が高いため細孔壁に付着するＰＭは多くなる。その後、多孔体の表面から遠い位置に入っていくほどガス中のＰＭ濃度は低減してくるので、細孔壁に付着するＰＭ量も次第に減少する。本発明のＤＰＦは、このＰＭの存在濃度の変化にできるだけ整合するように多孔体フィルタの細孔壁に担持されるペロブスカイト型複合酸化物触媒の量を変化させている。それにより、効率良くＰＭの燃焼を実現することができ、結果的にＰＭ燃焼開始温度の低減が可能になるものと考えられる。 The DPF of the present invention has a perovskite-type composite oxide catalyst material directly supported on the pore walls of a porous body that collects PM. In particular, the DPF contains exhaust gas in the thickness direction of the porous body. The structure is characterized in that the abundance of the perovskite complex oxide decreases from the side toward the outlet. PM enters the pores of the porous filter along with the flow of the exhaust gas and is trapped, but the higher the PM concentration in the exhaust gas is, the more the amount attached to the pore wall of the porous filter is thought to be. . That is, PM adhering to the pore walls increases because the PM concentration in the gas is high near the exhaust gas inlet side of the porous filter. Thereafter, the PM concentration in the gas decreases as the distance from the surface of the porous body decreases, so that the amount of PM adhering to the pore walls also gradually decreases. In the DPF of the present invention, the amount of the perovskite complex oxide catalyst supported on the pore walls of the porous filter is changed so as to match the change in the existing concentration of PM as much as possible. Thereby, it is considered that PM combustion can be realized efficiently, and as a result, the PM combustion start temperature can be reduced.
発明者らの検討の結果、厚さ方向においてペロブスカイト型複合酸化物の存在量に勾配をつけた多孔体フィルタは、ペロブスカイト型複合酸化物の前駆体スラリーを多孔体の排気ガス入り側表面から導入し、その後、焼成することによって得られることが判明した。前駆体は液中に溶解しているイオンとは異なり、有限の大きさを持つ粒子であるから、そのスラリーが多孔体の排気ガス入り側の表面から導入されると、スラリーが多孔体の内部（深さ方向）に進行する過程で前駆体の粒子は多孔体の細孔壁に付着していく。このため、前駆体の粒子は多孔体の厚さ方向に一定の濃度で存在するのではなく、排気ガス入り側表面近傍の存在濃度が最も高く、厚さ中央部、さらに排気ガス出側表面近傍に進むにしたがって存在濃度が減少していく。 As a result of investigations by the inventors, a porous filter having a gradient in the amount of perovskite complex oxide in the thickness direction introduces a precursor slurry of the perovskite complex oxide from the exhaust gas containing surface of the porous body. Then, it was found that it can be obtained by firing. Unlike the ions dissolved in the liquid, the precursor is a particle having a finite size. Therefore, when the slurry is introduced from the surface of the porous body on the exhaust gas inlet side, the slurry is inside the porous body. In the process of proceeding in the depth direction, the precursor particles adhere to the pore walls of the porous body. For this reason, the precursor particles do not exist at a constant concentration in the thickness direction of the porous body, but the concentration in the vicinity of the exhaust gas inlet side surface is the highest, the thickness center, and the exhaust gas outlet side surface vicinity As the process proceeds, the existing concentration decreases.
このような、多孔体フィルタの排気ガス導入表面からの深さ位置によって前駆体濃度に勾配を付けた状態で、当該多孔体フィルタをペロブスカイト型複合酸化物の焼成温度に加熱すると、合成されたペロブスカイト型複合酸化物触媒の存在状態も、前駆体の存在状態を反映したものとなる。 When the porous filter is heated to the firing temperature of the perovskite complex oxide in a state where the precursor concentration is gradient depending on the depth position from the exhaust gas introduction surface of the porous filter, the synthesized perovskite The presence state of the type complex oxide catalyst also reflects the presence state of the precursor.
詳細な研究の結果、排気ガス入り側表面上に付着しているペロブスカイト型複合酸化物触媒の存在濃度に比べ、排気ガス入り側表面からの深さが４０〜１２０μｍの領域における細孔壁面上のペロブスカイト型複合酸化物の存在濃度が少なくなっており、かつ、排気ガス入り側表面からの深さが１４０μｍ以上の領域における細孔壁面上のペロブスカイト型複合酸化物の存在濃度がさらに少なくなっているとき、この多孔体フィルタに捕集されるＰＭの燃焼が極めて効率的に実現されることが明らかになった。具体的には、ＰＭ燃焼開始温度の低減効果として現れてくる。ただし、上記４０〜１２０μｍの深さ領域には少なくともペロブスカイト型複合酸化物の存在が検出される必要がある。この領域にペロブスカイト型複合酸化物が存在しないようでは、極表層部のみにしかペロブスカイト型複合酸化物が存在していないことになり、多孔体の深さ方向内部に捕集されたＰＭの燃焼温度低下が不十分となる。なお、排気ガス入り側表面から１４０μｍ以上の深さ領域にはペロブスカイト型複合酸化物の存在が検出されなくても構わない。 As a result of detailed research, compared to the concentration of the perovskite-type composite oxide catalyst adhering to the exhaust gas containing surface, the depth from the exhaust gas containing surface is 40 to 120 μm on the pore wall surface. The concentration of the perovskite complex oxide is reduced, and the concentration of the perovskite complex oxide on the pore wall surface in the region where the depth from the exhaust gas containing surface is 140 μm or more is further decreased. At that time, it became clear that combustion of PM trapped in the porous filter was realized extremely efficiently. Specifically, it appears as a reduction effect of the PM combustion start temperature. However, it is necessary to detect the presence of at least the perovskite complex oxide in the depth region of 40 to 120 μm. If there is no perovskite type complex oxide in this region, the perovskite type complex oxide exists only in the extreme surface layer part, and the combustion temperature of PM collected in the depth direction inside the porous body The decrease is insufficient. Note that the presence of the perovskite complex oxide may not be detected in the depth region of 140 μm or more from the exhaust gas containing surface.
貴金属元素もＰＭ燃焼を助ける触媒作用を有することが知られている。本発明では、ペロブスカイト型複合酸化物の他に、貴金属元素（Ｐｔ、Ｐｄ、Ｒｈ等）を多孔体の細孔壁に存在させることができる。貴金属元素の場合は、必ずしもペロブスカイト型複合酸化物のように、多孔体の厚さ方向に濃度勾配を生じている必要はなく、一部分に存在していても良いし、厚さ方向にほぼ均一濃度で存在していても良い。 It is known that noble metal elements also have a catalytic action that assists PM combustion. In the present invention, in addition to the perovskite complex oxide, a noble metal element (Pt, Pd, Rh, etc.) can be present on the pore walls of the porous body. In the case of a noble metal element, it is not always necessary to have a concentration gradient in the thickness direction of the porous body like perovskite type complex oxide, and it may be present in a part or almost uniform concentration in the thickness direction. May exist.
本発明で触媒として用いるペロブスカイト型複合酸化物は、組成式ＡＭＯ3、ただしＡサイトは１種以上の希土類元素（Ｙも希土類元素として扱う）と１種以上のアルカリ土類金属元素、Ｍサイトは１種以上の遷移金属元素、で表されるものが好適に採用される。例えば、ＡサイトにはＬａ、Ｙ、Ｄｙ、Ｎｄ等の１種以上と、Ｓｒ、Ｂａ、Ｍｇ等の１種以上が入り、ＭサイトにはＭｎ、Ｆｅ、Ｃｏ等の１種以上が入るものが挙げられる。具体的には、Ｌａ1-XＳｒXＦｅＯ3（Ｘ：０.１〜０.６５）、Ｌａ1-XＢａXＦｅＯ3（Ｘ：０.１〜０.６５）などが挙げられる。
これらのペロブスカイト型複合酸化物の存在濃度をＥＤＳやＥＰＭＡなどにより確認するための測定元素としては、Ｌａ等の希土類元素を選択することができる。
The perovskite complex oxide used as a catalyst in the present invention has a composition formula AMO 3 , where the A site is one or more rare earth elements (Y is also treated as a rare earth element), one or more alkaline earth metal elements, and the M site is Those represented by one or more transition metal elements are preferably employed. For example, the A site contains one or more of La, Y, Dy, Nd, etc. and one or more of Sr, Ba, Mg, etc., and the M site contains one or more of Mn, Fe, Co, etc. Is mentioned. Specifically, La 1-X Sr X FeO 3 (X: 0.1~0.65), La 1-X Ba X FeO 3 (X: 0.1~0.65) , and the like.
A rare earth element such as La can be selected as a measurement element for confirming the concentration of these perovskite complex oxides by EDS or EPMA.
本発明のＤＰＦは以下のような製造法により作成することができる。
〔前駆体の製造〕
本発明で使用するペロブスカイト型複合酸化物の前駆体は、例えば、共沈法、有機錯体法、アルコキシド法、非晶質前駆体を用いた製法などによって製造することができる。以下、各製法について説明する。
The DPF of the present invention can be prepared by the following manufacturing method.
[Precursor production]
The precursor of the perovskite complex oxide used in the present invention can be produced, for example, by a coprecipitation method, an organic complex method, an alkoxide method, a production method using an amorphous precursor, or the like. Hereinafter, each manufacturing method will be described.
《共沈法》
共沈法では、例えば、前述のＡ成分およびＭ成分の塩を、ＡＭＯ3のペロブスカイト型複合酸化物を生成するにふさわしい化学量論比で含むように原料塩水溶液を調整し、この水溶液と中和剤を混合して共沈させた後、得られた共沈物を乾燥後、熱処理する。各元素の塩としては特に限定されないが、例えば硫酸塩、硝酸塩、リン酸塩、塩化物などの無機塩、酢酸塩、シュウ酸塩などの有機酸塩などが使用できる。中でも酢酸塩、硝酸塩が好適に使用できる。原料塩水溶液は、上記の各元素の塩を目的の化学量論比となるように水に加えて、攪拌することにより調製することができる。
《Coprecipitation method》
In the coprecipitation method, for example, a raw salt aqueous solution is prepared so as to contain the above-mentioned salts of the A component and the M component in a stoichiometric ratio suitable for forming a perovskite complex oxide of AMO 3. After mixing and coprecipitation, the obtained coprecipitate is dried and heat-treated. Although it does not specifically limit as a salt of each element, For example, organic acid salts, such as inorganic salts, such as a sulfate, nitrate, phosphate, and chloride, acetate, oxalate, etc. can be used. Of these, acetates and nitrates can be preferably used. The raw salt aqueous solution can be prepared by adding the salt of each of the above elements to water so as to achieve the desired stoichiometric ratio and stirring.
そして、この原料塩水溶液と中和剤を混合し、共沈させる。中和剤としては特に限定されないが、例えばアンモニア、苛性ソーダ、苛性カリなどの無機塩基、トリエチルアミン、ピリジンなどの有機塩基が使用できる。また中和剤は、その中和剤を加えた後に生成されるスラリーのｐＨが６〜１４となるように混合する。このように混合することにより、結晶性のよい各元素の水酸化物の共沈物を得ることができる。 Then, this raw salt aqueous solution and a neutralizing agent are mixed and coprecipitated. The neutralizing agent is not particularly limited, and for example, inorganic bases such as ammonia, caustic soda and caustic potash, and organic bases such as triethylamine and pyridine can be used. Moreover, a neutralizing agent is mixed so that the pH of the slurry produced | generated after adding the neutralizing agent may be 6-14. By mixing in this way, it is possible to obtain a coprecipitate of a hydroxide of each element having good crystallinity.
《有機錯体法》
有機錯体法では、例えばクエン酸、リンゴ酸、エチレンジアミン４酢酸ナトリウムなどの有機錯体を形成する塩と、前述の各元素の塩とを目的の化学量論比となるように水に加えて、攪拌することにより調製することができる。
《Organic Complex Method》
In the organic complex method, for example, a salt that forms an organic complex such as citric acid, malic acid, sodium ethylenediaminetetraacetate, and the salt of each of the aforementioned elements is added to water so as to achieve the desired stoichiometric ratio, and stirred. Can be prepared.
Ａ成分、Ｍ成分の塩としては、共沈法の場合と同様の塩が使用でき、また原料塩水溶液は各元素の原料塩を目的の化学量論比に混合して水に溶解した後、有機錯体を形成する塩の水溶液と混合することにより、調製することができる。なお、有機錯体を形成する塩の配合比率は得られるペロブスカイト型複合酸化物１モルに対して１.２〜３モル程度であることが好ましい。
その後、この原料溶液を乾固させて、前述の有機錯体を得る。乾固は有機錯体が分解しない温度であれば特に限定されず、例えば室温〜１５０℃程度、好ましくは室温〜１１０℃で、可及的速やかに水分を除去する。これにより前述の有機錯体が得られる。
As the salt of the A component and the M component, the same salt as in the coprecipitation method can be used, and the raw salt aqueous solution is prepared by mixing the raw salt of each element in the desired stoichiometric ratio and dissolving it in water. It can be prepared by mixing with an aqueous solution of a salt that forms an organic complex. In addition, it is preferable that the compounding ratio of the salt which forms an organic complex is about 1.2-3 mol with respect to 1 mol of perovskite type complex oxides obtained.
Thereafter, this raw material solution is dried to obtain the aforementioned organic complex. Drying is not particularly limited as long as it is a temperature at which the organic complex is not decomposed. For example, water is removed as quickly as possible at room temperature to 150 ° C, preferably at room temperature to 110 ° C. Thereby, the above-mentioned organic complex is obtained.
《アルコキシド法》
アルコキシド法では、例えば各元素のアルコキシドを目的の化学量論比で含むアルコキシド原料溶液を調整し、この原料溶液に水を反応させて加水分解することにより、沈殿物を得る。
《Alkoxide method》
In the alkoxide method, for example, an alkoxide raw material solution containing an alkoxide of each element in a target stoichiometric ratio is prepared, and this raw material solution is reacted with water to be hydrolyzed to obtain a precipitate.
各元素のアルコキシドとしては各元素が均一に混合される限り特に制限されないが、例えばメトキシ、エトキシ、プロポキシ、イソプロポキシ、ブトキシなどのアルコキシとから形成されるアルコラートが使用できる。これらのアルコキシドを目的の化学量論比になるように有機溶媒に溶解し、攪拌混合することによりアルコキシド原料溶液が得られる。有機溶媒としては、各元素のアルコキシドを溶解できれば特に制限されないが、例えばベンゼン、トルエン、キシレンなどが使用できる。そして、この原料溶液に水を加えて加水分解により沈殿物を生成させる。 The alkoxide of each element is not particularly limited as long as each element is uniformly mixed. For example, an alcoholate formed from alkoxy such as methoxy, ethoxy, propoxy, isopropoxy, butoxy and the like can be used. An alkoxide raw material solution is obtained by dissolving these alkoxides in an organic solvent so as to have a desired stoichiometric ratio and stirring and mixing them. The organic solvent is not particularly limited as long as it can dissolve the alkoxide of each element, and for example, benzene, toluene, xylene and the like can be used. And water is added to this raw material solution, and a precipitate is produced | generated by hydrolysis.
《非晶質前駆体を用いた製法》
非晶質前駆体を用いると、結晶質前駆体を用いた場合よりも低温で焼成することができ、経済的である。非晶質前駆体の製法は特開２００５−１８７３１１号公報に開示したが、簡単に説明すると以下のようなものである。
<Production method using amorphous precursor>
When an amorphous precursor is used, it can be fired at a lower temperature than when a crystalline precursor is used, which is economical. The method for producing the amorphous precursor is disclosed in Japanese Patent Application Laid-Open No. 2005-187111, but a brief description is as follows.
前述の各元素の塩をＡＭＯ3のペロブスカイト型複合酸化物を生成するにふさわしい化学量論比で含む原料塩水溶液を調整し、それと炭酸アルカリまたはアンモニウムイオンを含む炭酸塩などの沈殿剤とを、反応温度６０℃以下、ｐＨ６以上で反応させて沈殿生成物を作り、その濾過物を乾燥させて得ることができる。 A raw salt aqueous solution containing a salt of each of the above elements in a stoichiometric ratio suitable for forming a perovskite complex oxide of AMO 3 is prepared, and a precipitating agent such as a carbonate containing an alkali carbonate or ammonium ion, It can be obtained by reacting at a reaction temperature of 60 ° C. or lower and a pH of 6 or higher to produce a precipitated product, and drying the filtrate.
Ａ成分、Ｍ成分のモル比は、理想的にはほぼ１：１とするのがよいが、必ずしも厳密にその通りでなくてもペロブスカイト型複合酸化物を形成できることもある。したがって、各成分のモル比が上記理想比から多少ずれても、ペロブスカイト型複合酸化物が形成できるような値であればよい。 The molar ratio of the A component and the M component is ideally about 1: 1, but a perovskite complex oxide may be formed even if it is not strictly the case. Therefore, the value may be a value that can form a perovskite complex oxide even if the molar ratio of each component deviates slightly from the ideal ratio.
沈殿を生成させる液中のイオン濃度は、用いる塩類の溶解度によって上限が決まるが、結晶性化合物が析出しない状態が望ましく、通常は、Ａ成分、Ｍ成分の合計イオン濃度が０.０１〜０.６０ｍｏｌ／Ｌ程度の範囲であるのが望ましい。 The upper limit of the ion concentration in the liquid for generating the precipitate is determined by the solubility of the salts used, but it is desirable that the crystalline compound does not precipitate. Usually, the total ion concentration of the A component and the M component is 0.01 to 0.00. A range of about 60 mol / L is desirable.
この液から非晶質の沈殿を得るには、炭酸アルカリまたはアンモニウムイオンを含む炭酸塩からなる沈殿剤を用いるのがよく、このような沈殿剤としては、炭酸ナトリウム、炭酸水素ナトリウム、炭酸アンモニウム、炭酸水素アンモニウム等を使用することができ、必要に応じて、水酸化ナトリウム、アンモニア等の塩基を加えることも可能である。また、水酸化ナトリウム、アンモニア等を用いて沈殿を形成した後、炭酸ガスを吹き込むことによっても本発明に使用するペロブスカイト型複合酸化物の前駆体物質に適した非晶質を得ることができる。非晶質の沈殿を得る際、液のｐＨを６〜１１の範囲に制御するのがよい。ｐＨが６未満の領域では、希土類元素が沈殿を形成しない場合があるので不適切である。他方、ｐＨが１１を超える領域では、沈殿剤単独の場合には生成する沈殿の非晶質化が十分に進行せずに、水酸化物などの結晶性の沈殿を形成する場合がある。また、反応温度は６０℃以下にするのがよい。６０℃を超える温度で反応を開始した場合、結晶性の化合物粒子が生成する場合があり、前駆体物質の非晶質化を妨げるので好ましくない。 In order to obtain an amorphous precipitate from this liquid, it is preferable to use a precipitating agent composed of a carbonate containing an alkali carbonate or ammonium ion. Examples of such a precipitating agent include sodium carbonate, sodium hydrogen carbonate, ammonium carbonate, Ammonium hydrogen carbonate or the like can be used, and a base such as sodium hydroxide or ammonia can be added as necessary. Moreover, after forming a precipitate using sodium hydroxide, ammonia or the like, an amorphous suitable for the precursor material of the perovskite complex oxide used in the present invention can be obtained by blowing carbon dioxide gas. When obtaining an amorphous precipitate, the pH of the liquid should be controlled in the range of 6-11. In the region where the pH is less than 6, the rare earth element may not form a precipitate, which is inappropriate. On the other hand, in the region where the pH exceeds 11, in the case of the precipitating agent alone, the generated precipitate may not be sufficiently amorphized and a crystalline precipitate such as a hydroxide may be formed. The reaction temperature is preferably 60 ° C. or lower. When the reaction is started at a temperature exceeding 60 ° C., crystalline compound particles may be formed, which is not preferable because it prevents the precursor material from becoming amorphous.
〔前駆体の多孔体細孔中への導入〕
上記のようにして得られた前駆体をスラリー状態にしてＰＭ捕集用の多孔体に、排気ガス入り側表面から導入する。前駆体生成後のスラリーをそのまま、あるいは適宜濃度調整して使用することができるが、乾燥固化した前駆体物質を使用するときはイオン交換水等の溶媒に乾燥固化品を投入してスラリー化すればよい。その際に、均一性を得るために、界面活性剤等の分散剤を投入することも出来る。分散剤は後の焼成時に悪影響を及ぼさないようにすることが必要で、直鎖アルキル基を持つものであれば、できるだけその長さが短い方が焼成時に除かれやすいので好ましい。
[Introduction of precursor into porous pores]
The precursor obtained as described above is made into a slurry state and introduced into the PM collection porous body from the exhaust gas-containing surface. The slurry after the precursor generation can be used as it is or after adjusting the concentration appropriately. However, when using the dried and solidified precursor material, the dried solidified product is charged into a solvent such as ion-exchanged water to form a slurry. That's fine. At that time, in order to obtain uniformity, a dispersant such as a surfactant may be added. It is necessary for the dispersing agent not to adversely affect the subsequent firing, and if it has a linear alkyl group, it is preferable that its length is as short as possible because it is easier to remove during firing.
多孔体はコーディエライトや炭化珪素（ＳｉＣ）を主成分とする既存のものが適用できる。通常、この多孔体はハニカム状の空洞を有するように筒体の中にセットされ、筒体の一端部でハニカムの空洞のうち半分がいわば市松状に目封止され、他端部で残りの空洞が市松状に目封止されている。そして、筒体の一端部からディーゼルエンジンの排気ガスを導入すると、ハニカムの隣り合う空洞の間にある「多孔体の壁」の内部を通ったガスが、筒体の他端部から出てくるようになっており、その際、ＰＭは「多孔体の壁」の中の細孔に捕集される仕組みになっている。 As the porous material, an existing material mainly composed of cordierite or silicon carbide (SiC) can be applied. Usually, this porous body is set in a cylinder so as to have a honeycomb-shaped cavity, and half of the honeycomb cavities are plugged in a so-called checkered pattern at one end of the cylinder, and the remaining at the other end. The cavity is plugged in a checkered pattern. When the exhaust gas of the diesel engine is introduced from one end of the cylinder, the gas passing through the “porous wall” between adjacent cavities of the honeycomb comes out from the other end of the cylinder. In this case, PM is trapped in the pores in the “porous body wall”.
この多孔体の細孔中に前駆体スラリーを導入するには、多孔体物質でできたハニカム状の部材において、端部の市松状の目封止を終えた状態のもの（以下、これを「ハニカム体」と呼ぶ）について、排気ガスを導入する方の端部からスラリーを導入することが効率的である。ハニカム体は実際に使用する筒体にセットしたのちスラリーの導入に供しても良いが、スラリーの導入時には仮の筒体に装入しておくことでも良い。スラリーの導入の方法は、ハニカム体の排気ガスが出てくる端部側からスラリーを吸引する方法で行うことが好適である。この場合、多孔体が濾材の役目をする「吸引濾過」の原理によって、多孔体の細孔壁に前駆体粒子を付着させることができる。その際、多孔体の排気ガス入り側の表面からスラリーが多孔体内部に進入して濾し取られるので、前駆体粒子は前述のように多孔体の厚さ方向に濃度勾配をもって存在することになる。この吸引濾過の操作は複数回繰り返して行っても良い。 In order to introduce the precursor slurry into the pores of the porous body, in the honeycomb-shaped member made of the porous material, the end of the checkered plugged ends (hereinafter referred to as “ It is efficient to introduce the slurry from the end where the exhaust gas is introduced. The honeycomb body may be set to a cylinder that is actually used and then used for introduction of the slurry. However, the honeycomb body may be charged into a temporary cylinder when the slurry is introduced. The method of introducing the slurry is preferably performed by a method of sucking the slurry from the end portion side from which the exhaust gas of the honeycomb body exits. In this case, the precursor particles can be attached to the pore walls of the porous body by the principle of “suction filtration” in which the porous body serves as a filter medium. At that time, since the slurry enters the porous body from the surface of the porous body on the exhaust gas entering side and is filtered, the precursor particles exist with a concentration gradient in the thickness direction of the porous body as described above. . This suction filtration operation may be repeated a plurality of times.
〔焼成〕
次に、前駆体を細孔壁に付着させたハニカム体をペロブスカイト型複合酸化物が結晶化する温度にて焼成処理する。焼成時の温度が低すぎるとペロブスカイト型複合酸化物の合成が進まない。逆に温度が高すぎるとペロブスカイトの触媒活性が失活することがあるので１０００℃以下の焼成温度に抑えることが望ましい。非晶質前駆体の場合は比較的低温でも焼成が可能であり、例えば４００〜１０００℃、好ましくは４５０〜９００℃、より好ましくは４５０〜７００℃未満で焼成すればよい。熱処理雰囲気は大気あるいは酸素雰囲気が採用できる。焼成時間は概ね０.５〜１０ｈｒの範囲で調整できる。この焼成により、ペロブスカイト型複合酸化物の触媒を、多孔体の細孔壁に直接担持させることができる。
[Baking]
Next, the honeycomb body in which the precursor is adhered to the pore walls is fired at a temperature at which the perovskite complex oxide is crystallized. If the firing temperature is too low, synthesis of the perovskite complex oxide will not proceed. On the contrary, if the temperature is too high, the catalytic activity of the perovskite may be deactivated. In the case of an amorphous precursor, it can be fired even at a relatively low temperature. For example, it may be fired at 400 to 1000 ° C., preferably 450 to 900 ° C., more preferably 450 to 700 ° C. An air or oxygen atmosphere can be adopted as the heat treatment atmosphere. The firing time can be adjusted in a range of approximately 0.5 to 10 hours. By this firing, the catalyst of the perovskite complex oxide can be directly supported on the pore walls of the porous body.
〔貴金属元素の担持〕
ハニカム中には上述のように貴金属元素を含有させることができる。ペロブスカイト型複合酸化物はディーゼル排ガス中に含まれる一酸化窒素を吸着して吸蔵し、二酸化窒素に転換する働きを有することが確かめられているが、貴金属元素は一酸化窒素を二酸化窒素へ直接変換させることができるので、ペロブスカイト型複合酸化物と貴金属元素の併用によってＰＭ燃焼触媒としての活性が一層向上すると考えられる。貴金属元素を多孔体中に担持させるには、前駆体スラリー中へ貴金属元素を含有させておくことによっても可能であるが、前駆体を多孔体の細孔壁に存在させ、乾燥固着させてから、当該ハニカム体を貴金属の水溶液中に浸漬した後に乾燥し、還元雰囲気下において、壁内で貴金属が析出する状態にしておいた方が、ガス態を壁内で二酸化窒素に変換し、壁表層部分でカーボンの燃焼を生じさせるという役割分担を効率よく実現できるため好ましい。
[Supporting precious metal elements]
The honeycomb can contain a noble metal element as described above. Perovskite complex oxide has been confirmed to have the function of adsorbing and storing nitrogen monoxide contained in diesel exhaust gas and converting it to nitrogen dioxide, but precious metal elements directly convert nitrogen monoxide to nitrogen dioxide. Therefore, it is considered that the activity as the PM combustion catalyst is further improved by the combined use of the perovskite complex oxide and the noble metal element. In order to support the noble metal element in the porous body, it is possible to contain the noble metal element in the precursor slurry, but after the precursor is present on the pore wall of the porous body and dried and fixed, If the honeycomb body is immersed in a noble metal aqueous solution and then dried and the noble metal is precipitated in the wall in a reducing atmosphere, the gas state is converted into nitrogen dioxide in the wall, and the wall surface layer This is preferable because the role sharing of causing carbon combustion in the portion can be efficiently realized.
〔実施例１〕
ランタンの硝酸水溶液とバリウムの硝酸水溶液および鉄の硝酸水溶液をそれぞれ準備して、モル比で金属成分としてＬａ：Ｂａ：Ｆｅ＝３：２：５になるように調整した。これらの水溶液をイオン交換水との総量が４０００ｍＬになるように調整し、７２０ｒｐｍで攪拌しながらイオン交換水中に投入した。このときの金属成分は、合計で０.１ｍｏｌ／Ｌになるように調整している。溶液を液温２０℃に調整した後に、攪拌を停止し、炭酸アンモニウムを２当量添加した。その後、回転数５００ｒｐｍで攪拌を再開し、その状態で１時間熟成を行い、ペロブスカイト型複合酸化物を合成するための前駆体スラリーを得た。この前駆体はＸ線回折の結果、はっきりとした回折ピークが検出されず、実質的に非晶質であることが確認された（後述実施例２、比較例１、３、４において同じ）。
[Example 1]
A lanthanum nitric acid aqueous solution, a barium nitric acid aqueous solution and an iron nitric acid aqueous solution were prepared, respectively, and adjusted so that the molar ratio was La: Ba: Fe = 3: 2: 5. These aqueous solutions were adjusted so as to have a total amount of 4000 mL with ion-exchanged water, and poured into ion-exchanged water while stirring at 720 rpm. The metal components at this time are adjusted to be 0.1 mol / L in total. After adjusting the solution temperature to 20 ° C., stirring was stopped and 2 equivalents of ammonium carbonate was added. Thereafter, stirring was resumed at a rotational speed of 500 rpm, and aging was carried out for 1 hour in this state to obtain a precursor slurry for synthesizing a perovskite complex oxide. As a result of X-ray diffraction, no clear diffraction peak was detected, and this precursor was confirmed to be substantially amorphous (the same applies to Example 2, Comparative Examples 1, 3, and 4 described later).
ＰＭを捕集するための多孔体フィルタとして、コーディエライトのハニカム体を用意した。ハニカムの隣り合う空洞は厚さ約１ｍｍの多孔体の壁で隔てられており、壁の間隔（空洞の内径）は約３ｍｍである。ハニカム体の長さは約６０ｍｍであり、両端部は互い違いに市松状の目封止がされている。このハニカム体を直径２５ｍｍのステンレス鋼板製の筒体の中に装入した。この筒体を、一方の端部を上にして吸引濾過装置にセットし、その筒体の下端部から吸引できるようにした。そして、前記スラリーの一部をハニカム体の空洞を含めた容積に対する担持量がペロブスカイト型複合酸化物換算で２５ｇ／Ｌとなるように分取し、目封止されたハニカム体の上端部から徐々に添加し、下部より吸引濾過することで、多孔体の壁によってスラリーを濾し取った。ハニカム体の下部から吸引されて出てくる液はほとんど無色透明になっていた。 A cordierite honeycomb body was prepared as a porous filter for collecting PM. The adjacent cavities of the honeycomb are separated by a wall of a porous body having a thickness of about 1 mm, and the interval between the walls (the inner diameter of the cavity) is about 3 mm. The length of the honeycomb body is about 60 mm, and both end portions are alternately checkered. This honeycomb body was placed in a cylinder made of a stainless steel plate having a diameter of 25 mm. The cylinder was set in a suction filtration device with one end facing up so that the cylinder could be sucked from the lower end. Then, a part of the slurry is fractionated so that the supported amount with respect to the volume including the cavities of the honeycomb body is 25 g / L in terms of perovskite type complex oxide, and gradually from the upper end of the plugged honeycomb body. The slurry was filtered through the wall of the porous body by suction filtration from the bottom. The liquid sucked out from the lower part of the honeycomb body was almost colorless and transparent.
その後、このハニカム体を上記ステンレス鋼製の筒から取り出して、大気中６００℃で２ｈ保持することによって焼成処理を施し、ＤＰＦを得た。
このＤＰＦと、何も担持していない状態のＤＰＦについて、以下のようにして圧損を測定し、比較した。すなわち、ハニカム体の外径に一致する内径をもつ金属製筒であって、一端が圧縮空気タンクに配管で接続され、他端が開口端になっているものを用意し、被測定用のハニカム体をその排気ガス導入側の端面が空気タンク側になるように前記筒に装入し、筒の開口端に金網の蓋を固定することによってハニカム体が開口端から出ないようにしたのち、圧縮空気タンクから２ａｔｍの一定圧力になるように弁を調整してハニカム体に空気を送り込み、そのときの配管を流れる空気の流量を測定した。この流量が大きいほどハニカム体の圧損が小さいと判定した。
Thereafter, the honeycomb body was taken out of the stainless steel tube and held in the atmosphere at 600 ° C. for 2 hours to be fired to obtain a DPF.
The pressure loss was measured and compared for this DPF and the DPF in which nothing was supported as follows. That is, a metal cylinder having an inner diameter that matches the outer diameter of the honeycomb body, one end of which is connected to a compressed air tank by a pipe and the other end is an open end, is prepared. After inserting the body into the cylinder so that the end face on the exhaust gas introduction side is on the air tank side, and fixing the lid of the wire mesh to the opening end of the cylinder, the honeycomb body does not come out from the opening end, The valve was adjusted from the compressed air tank to a constant pressure of 2 atm, air was sent to the honeycomb body, and the flow rate of air flowing through the piping at that time was measured. It was determined that the greater the flow rate, the smaller the pressure loss of the honeycomb body.
別途この条件で焼成したハニカム体を分解して集めた粉体についてＸ線回折を行ったところ、ペロブスカイト型複合酸化物が合成されたことが確認された。また、この多孔体の壁からサンプルを切り出し、厚さ方向の断面について、日本電子株式会社製のＥＰＭＡ装置を用いてＢａの存在濃度をマッピング法により調べ、「排気ガス入り側表面上」、「排気ガス入り側表面からの深さが４０〜１２０μｍ位置の細孔壁面上」、および「排気ガス入り側表面からの深さが１４０μｍ以上の位置の細孔壁面上」におけるＢａの存在量の大小関係を調べた。それぞれの深さ位置でのＢａ存在量は、異なる５視野において得られた測定値の平均値を採用した。 Separately, X-ray diffraction was performed on the powder collected by disassembling the honeycomb bodies fired under these conditions, and it was confirmed that a perovskite-type composite oxide was synthesized. In addition, a sample was cut out from the wall of the porous body, and the cross-section in the thickness direction was examined for the concentration of Ba using an EPMA apparatus manufactured by JEOL Ltd. by a mapping method. The amount of Ba present on the pore wall surface at a depth of 40 to 120 μm from the exhaust gas containing surface and “on the pore wall surface at a depth of 140 μm or more from the exhaust gas containing surface” I investigated the relationship. As the Ba abundance at each depth position, an average value of measured values obtained in five different visual fields was adopted.
図１には実施例１における多孔体壁断面のＥＰＭＡ測定におけるＬａ、Ｂａ、Ｆｅの濃度分布を示す。左側のＳＥＭ像で黒く見える島上の部分が細孔である。楕円の破線のうち、最も左が排気ガス入り側表面付近であり、白の矢印方向が深さ方向である。この視野においては楕円の破線の位置におけるＢａの検出量を、上記３箇所の測定値とした。なお、オリジナル画像ではＬａ、Ｂａ、Ｆｅの検出量はカラー表示されており、最も検出量の多い部分が赤で表示されている。 FIG. 1 shows the concentration distribution of La, Ba, and Fe in EPMA measurement of the cross section of the porous body wall in Example 1. The portion of the island that appears black in the left SEM image is a pore. Among the elliptical broken lines, the leftmost is the vicinity of the exhaust gas containing surface, and the white arrow direction is the depth direction. In this field of view, the detected amount of Ba at the position of the elliptical broken line was the measured value at the above three locations. In the original image, the detected amounts of La, Ba, and Fe are displayed in color, and the portion with the largest detected amount is displayed in red.
このＤＰＦに模擬ＰＭを捕集させ、以下のようにしてＰＭ燃焼開始温度を測定した。
模擬ＰＭとして三菱化学製カーボンブラック（平均粒径２.０９μｍ）を使用し、これををＤＰＦ１００質量部あたり２質量％の割合で多孔体フィルタに投入させた。このとき、先にスラリーを導入した方のＤＰＦの端部から、模擬ＰＭをエアーに乗せて吹き込むことにより吹き込むことにより投入させている。その後、大気、またはディーゼルエンジン模擬排ガス（ＮＯ：５００ｐｐｍ、Ｏ2：１０％、残部Ｎ2）を先にスラリーを導入した方の端部からＤＰＦの内部に０.２５ｍＬ／ｍｉｎで吹き込みながら昇温速度１０℃／ｍｉｎの条件にて昇温し、出口側にて出てくる処理後のガスを分取して、ガス中成分の分析が可能なＦＴ−ＩＲ装置（Ｎｉｃｏｌｅｔ社製）にて排ガス成分のＣＯ、ＣＯ2、ＮＯおよびＮＯ2の定量値をモニターした。そして、排出されるＣＯ2の積算量がＣＯ2の総排出量の１０体積％に相当する時点での温度をＰＭ燃焼開始温度として求めた。
The simulated PM was collected by this DPF, and the PM combustion start temperature was measured as follows.
Carbon black (average particle size: 2.09 μm) manufactured by Mitsubishi Chemical was used as a simulated PM, and this was put into a porous filter at a rate of 2 mass% per 100 parts by mass of DPF. At this time, from the end of the DPF into which the slurry has been introduced first, the simulated PM is put in by being blown by being blown on air. Thereafter, the temperature was raised while blowing the atmosphere or diesel engine simulated exhaust gas (NO: 500 ppm, O 2 : 10%, balance N 2 ) from the end where the slurry was first introduced into the DPF at 0.25 mL / min. The temperature is raised at a rate of 10 ° C./min, the treated gas coming out at the outlet side is collected, and exhaust gas is exhausted with an FT-IR apparatus (manufactured by Nicolet) capable of analyzing components in the gas. The quantitative values of the components CO, CO 2 , NO and NO 2 were monitored. Then, to determine the temperature at the time when the integrated amount of CO 2 to be discharged is equal to 10% by volume of the total emissions of CO 2 as the PM combustion start temperature.
ＰＭ燃焼開始温度については従来例に相当する後述比較例１（リファレンス）との差異により評価した（以下の各例において同じ）。圧損は、何も担持していないＤＰＦとの差異により評価した（以下の各例において同じ）。結果を表１に示す。 The PM combustion start temperature was evaluated based on a difference from a later-described comparative example 1 (reference) corresponding to the conventional example (the same applies to the following examples). The pressure loss was evaluated by the difference from the DPF carrying nothing (the same applies in the following examples). The results are shown in Table 1.
〔実施例２〕
ハニカム体に吸引濾過により前駆体を導入したのち、ハニカム体を１５０℃×２ｈの乾燥により固着させてから、テトラヒドラジン白金酸の１.０質量％水溶液へハニカム体を浸漬させることにより、白金を多孔体の細孔壁に被着させたこと以外、実施例１と同様の実験を行った。結果を表１に示す。
[Example 2]
After the precursor was introduced into the honeycomb body by suction filtration, the honeycomb body was fixed by drying at 150 ° C. × 2 h, and then the honeycomb body was immersed in a 1.0 mass% aqueous solution of tetrahydrazine platinic acid to thereby remove platinum. The same experiment as in Example 1 was conducted except that the porous body was deposited on the pore walls. The results are shown in Table 1.
〔比較例１〕
実施例１と同様にして得た前駆体を大気中６００℃で２ｈで焼成したのち、従来と同様のウオッシュコート法によりハニカム体の多孔体表面に塗布したこと以外、実施例１と同様の実験を行った。この例をリファレンスとして、他の例のＰＭ燃焼開始温度を評価した（表１）。
[Comparative Example 1]
The same experiment as in Example 1 except that the precursor obtained in the same manner as in Example 1 was fired in the atmosphere at 600 ° C. for 2 h, and then applied to the porous body surface of the honeycomb body by the same wash coat method. Went. Using this example as a reference, PM combustion start temperatures of other examples were evaluated (Table 1).
〔比較例２〕
特許文献１０の実施例にならって、原料の金属イオンが溶解している溶液にハニカム体を浸漬したのち、このハニカム体を加熱する方法でペロブスカイト型複合酸化物を多孔体に担持した。ただし、ここでは貴金属元素としてパラジウムの代わりに白金を使用した。得られたＤＰＦについて実施例１と同様の実験を行った。結果を表１に示す。
[Comparative Example 2]
In accordance with the example of Patent Document 10, the honeycomb body was immersed in a solution in which the raw material metal ions were dissolved, and then the perovskite complex oxide was supported on the porous body by a method of heating the honeycomb body. However, here, platinum was used as a noble metal element instead of palladium. The same experiment as in Example 1 was performed on the obtained DPF. The results are shown in Table 1.
〔比較例３〕
焼成温度を３５０℃にした以外、実施例１と同様の実験を行った。Ｘ線回折の結果、得られた焼成物質は十分に結晶化しておらず、ペロブスカイト型複合酸化物の生成が不十分であった。結果を表１に示す。
[Comparative Example 3]
The same experiment as in Example 1 was performed except that the firing temperature was 350 ° C. As a result of X-ray diffraction, the obtained fired material was not sufficiently crystallized, and the formation of perovskite complex oxide was insufficient. The results are shown in Table 1.
〔比較例４〕
焼成温度を１２００℃としたこと以外、実施例１と同様の実験を行った。Ｘ線回折の結果、得られた焼成物質は結晶化しているものの、焼成温度がペロブスカイト型複合酸化物の生成温度域を超えて高かったことにより、焼成体の触媒活性は低い結果となった。表１に結果を示す。
[Comparative Example 4]
The same experiment as in Example 1 was performed except that the firing temperature was 1200 ° C. As a result of X-ray diffraction, although the obtained calcined material was crystallized, the calcining temperature was higher than the formation temperature range of the perovskite type complex oxide, so that the catalytic activity of the calcined product was low. Table 1 shows the results.
表１からわかるように、実施例のものは圧損の低下が少なく、ＰＭ燃焼開始温度は、大気中および模擬排ガス中のいずれにおいても大きく低下した。とくに実施例２では貴金属元素の効果により模擬排ガス中でのＰＭ燃焼温度の低下が実施例１よりもさらに低下した。
これに対し、比較例１ではウオッシュコート法により多孔体の排気ガス入り側表面の上に層状のペロブスカイト型複合酸化物を設けたことにより、圧損は大きく低下した。ＰＭ燃焼開始温度は実施例１よりも高い。
比較例２ではイオンの状態で原料物質を多孔体の細孔中に厚さ方向でほぼ一様濃度に存在させたことにより、ＰＭの付着量が多い排気ガス入り側表面付近から中央部にかけての触媒量が不足し、ＰＭ燃焼開始温度の低下は実施例のものより小さかった。
比較例３および４では焼成条件が不適切であったことにより触媒活性の高いペロブスカイト型複合酸化物が十分に生成しておらず、触媒効果が不十分のためＰＭ燃焼開始温度はリファレンスよりむしろ高かった。
As can be seen from Table 1, the pressure loss of the example was small, and the PM combustion start temperature was greatly reduced both in the atmosphere and in the simulated exhaust gas. Particularly in Example 2, due to the effect of the noble metal element, the decrease in PM combustion temperature in the simulated exhaust gas was further reduced as compared with Example 1.
In contrast, in Comparative Example 1, the pressure loss was greatly reduced by providing the layered perovskite complex oxide on the exhaust gas-containing side surface of the porous body by the wash coat method. The PM combustion start temperature is higher than that in the first embodiment.
In Comparative Example 2, since the source material was present in the pores of the porous body at a substantially uniform concentration in the thickness direction in the state of ions, from the vicinity of the surface containing the exhaust gas having a large amount of PM attached to the central portion. The catalyst amount was insufficient, and the decrease in the PM combustion start temperature was smaller than that of the example.
In Comparative Examples 3 and 4, the perovskite complex oxide having high catalytic activity was not sufficiently formed due to inappropriate firing conditions, and the PM combustion start temperature was rather higher than the reference due to insufficient catalytic effect. It was.
Claims (5)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006059226A JP5233026B2 (en) | 2006-03-06 | 2006-03-06 | Manufacturing method of DPF |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2006059226A JP5233026B2 (en) | 2006-03-06 | 2006-03-06 | Manufacturing method of DPF |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007237012A JP2007237012A (en) | 2007-09-20 |
| JP5233026B2 true JP5233026B2 (en) | 2013-07-10 |
Family
ID=38583084
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2006059226A Expired - Fee Related JP5233026B2 (en) | 2006-03-06 | 2006-03-06 | Manufacturing method of DPF |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5233026B2 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008139564A1 (en) * | 2007-05-07 | 2008-11-20 | Ibiden Co., Ltd. | Honeycomb filter |
| JP4916989B2 (en) * | 2007-09-27 | 2012-04-18 | 本田技研工業株式会社 | Exhaust gas purification device and method of manufacturing the exhaust gas purification device |
| JP2009136787A (en) | 2007-12-06 | 2009-06-25 | Honda Motor Co Ltd | Method of manufacturing oxidation catalyst device for purification of exhaust gas |
| JP5330018B2 (en) * | 2008-04-22 | 2013-10-30 | 本田技研工業株式会社 | Oxidation catalyst |
| EP2269731B1 (en) | 2008-04-22 | 2012-07-11 | Honda Motor Co., Ltd. | Oxidation catalyst and oxidation catalyst device for exhaust gas purification |
| JP5330044B2 (en) * | 2008-07-15 | 2013-10-30 | 本田技研工業株式会社 | Oxidation catalyst equipment for exhaust gas purification |
| JP4987794B2 (en) * | 2008-04-25 | 2012-07-25 | 本田技研工業株式会社 | Manufacturing method of oxidation catalyst device for exhaust gas purification |
| EP2113303B1 (en) | 2008-04-25 | 2013-10-16 | Honda Motor Co., Ltd. | Production method of oxidation catalyst device for exhaust gas purification |
| JP5052401B2 (en) * | 2008-04-28 | 2012-10-17 | 本田技研工業株式会社 | Manufacturing method of oxidation catalyst device for exhaust gas purification |
| JP2009262102A (en) * | 2008-04-28 | 2009-11-12 | Honda Motor Co Ltd | Oxidation catalyst device for purification of exhaust gas |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62277150A (en) * | 1986-05-26 | 1987-12-02 | Toyota Motor Corp | Catalyst for purifying exhaust gas |
| JP2577757B2 (en) * | 1987-10-22 | 1997-02-05 | 株式会社日本触媒 | Diesel exhaust gas purification catalyst |
| JPH0629542B2 (en) * | 1987-11-30 | 1994-04-20 | トヨタ自動車株式会社 | Diesel particulate collection filter |
| JPH0217911A (en) * | 1988-07-06 | 1990-01-22 | Toyota Motor Corp | Combustible waste removing apparatus of internal combustion engine |
| JPH0372916A (en) * | 1989-08-11 | 1991-03-28 | Sakai Chem Ind Co Ltd | Treatment of exhaust gas |
| JPH07136518A (en) * | 1993-11-22 | 1995-05-30 | Nissan Motor Co Ltd | Exhaust gas purifying catalyst |
| JPH07150927A (en) * | 1993-11-29 | 1995-06-13 | Isuzu Ceramics Kenkyusho:Kk | Diesel particulate filter and manufacture thereof |
| JP3674554B2 (en) * | 2001-08-17 | 2005-07-20 | 日産自動車株式会社 | Catalyst coating method for exhaust particulate filter |
| JP4112933B2 (en) * | 2001-09-28 | 2008-07-02 | 株式会社日本触媒 | Exhaust gas treatment catalyst and exhaust gas treatment method |
| JP3874270B2 (en) * | 2002-09-13 | 2007-01-31 | トヨタ自動車株式会社 | Exhaust gas purification filter catalyst and method for producing the same |
| JP4765094B2 (en) * | 2003-03-28 | 2011-09-07 | Ｄｏｗａエレクトロニクス株式会社 | Method for producing perovskite complex oxide |
| JP4508597B2 (en) * | 2003-10-17 | 2010-07-21 | 三菱重工業株式会社 | Exhaust gas treatment catalyst capable of SO3 reduction treatment, method for producing the same, and exhaust gas treatment method using the exhaust gas treatment catalyst |
-
2006
- 2006-03-06 JP JP2006059226A patent/JP5233026B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007237012A (en) | 2007-09-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5233026B2 (en) | Manufacturing method of DPF | |
| EP2216087B1 (en) | Exhaust gas cleaner | |
| WO2008004687A1 (en) | Exhaust gas purifying catalyst | |
| JP5581314B2 (en) | Exhaust gas purification catalyst | |
| EP2441510B1 (en) | Oxidation catalyst device for exhaust gas purification | |
| JP5190308B2 (en) | Exhaust gas purification catalyst | |
| JP2007209913A (en) | Catalysts material, its production method, and diesel particulate filter | |
| WO2006064809A1 (en) | Heat-resistant oxide | |
| JP2005262201A (en) | Exhaust gas-cleaning catalyst and method for manufacturing the same | |
| CN105813733A (en) | Exhaust gas purifying catalyst | |
| US9006131B2 (en) | Composite oxide for exhaust gas purification catalyst, method for manufacturing the same, coating material for exhaust gas purification catalyst, and filter for diesel exhaust gas purification | |
| KR101574553B1 (en) | Composite oxide for catalyst for exhaust gas purification, process for producing the same, coating composition for catalyst for exhaust gas purification, and filter for diesel exhaust gas purification | |
| WO2007113981A1 (en) | Catalyst composition | |
| JP2009061432A (en) | Compound oxide, particulate oxidation catalyst, and diesel particulate filter | |
| WO2010110298A1 (en) | Exhaust gas purifying catalyst | |
| JP2012217931A (en) | Catalyst for cleaning exhaust gas | |
| JP6077367B2 (en) | Exhaust gas purification catalyst | |
| JPWO2015087781A1 (en) | Exhaust gas purification catalyst | |
| JP5564962B2 (en) | Exhaust gas purification filter | |
| JP6194699B2 (en) | Manufacturing method of particulate filter with catalyst | |
| JP2007260564A (en) | Exhaust gas-purifying catalyst and method for regenerating the same | |
| JP2013017992A (en) | Catalyst-carried diesel particulate filter, and method for manufacturing the same | |
| JP2011016091A (en) | Exhaust gas purifying catalyst | |
| JP2010172848A (en) | Catalyst for cleaning exhaust gas and method for manufacturing the same | |
| CN106944094A (en) | Exhaust gas purification catalyst |
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: 20101224 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110524 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110706 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120424 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120615 |
|
| 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: 20130205 |
|
| A711 | Notification of change in applicant |
Free format text: JAPANESE INTERMEDIATE CODE: A712 Effective date: 20130306 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130306 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20130306 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 Ref document number: 5233026 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20160405 Year of fee payment: 3 |
|
| 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 |