JP2004002148A - Metal oxide, its manufacturing method and catalyst - Google Patents
Metal oxide, its manufacturing method and catalyst Download PDFInfo
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- JP2004002148A JP2004002148A JP2003032611A JP2003032611A JP2004002148A JP 2004002148 A JP2004002148 A JP 2004002148A JP 2003032611 A JP2003032611 A JP 2003032611A JP 2003032611 A JP2003032611 A JP 2003032611A JP 2004002148 A JP2004002148 A JP 2004002148A
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- metal oxide
- surfactant
- pore volume
- precipitate
- catalyst
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- 239000003054 catalyst Substances 0.000 title claims abstract description 54
- 229910044991 metal oxide Inorganic materials 0.000 title claims abstract description 40
- 150000004706 metal oxides Chemical class 0.000 title claims abstract description 40
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- 239000011148 porous material Substances 0.000 claims abstract description 83
- 239000004094 surface-active agent Substances 0.000 claims abstract description 39
- 239000002244 precipitate Substances 0.000 claims abstract description 36
- 239000007864 aqueous solution Substances 0.000 claims abstract description 29
- 238000003756 stirring Methods 0.000 claims abstract description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910052751 metal Inorganic materials 0.000 claims abstract description 19
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- 239000000126 substance Substances 0.000 claims abstract description 15
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- 239000000843 powder Substances 0.000 claims description 43
- 239000006104 solid solution Substances 0.000 claims description 31
- 239000002243 precursor Substances 0.000 claims description 20
- 229910052684 Cerium Inorganic materials 0.000 claims description 13
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 11
- 238000010304 firing Methods 0.000 claims description 9
- 238000005406 washing Methods 0.000 claims description 9
- 229910000510 noble metal Inorganic materials 0.000 claims description 7
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Images
Abstract
Description
【０００１】
【発明の属する技術分野】
本発明は、自動車の排ガス浄化触媒の触媒担体として用いられる金属酸化物とその製造方法及び触媒に関する。本発明の金属酸化物は、これ以外にディーゼルパティキュレート酸化触媒用の触媒担体、固体電解質、電極材料、セラミックス分散強化粒子、紫外線遮蔽用材料などにも用いることができる。
【０００２】
【従来の技術】
セリアは酸素吸蔵放出能（ ＯＳＣ）を有するため、内燃機関からの排ガスを浄化する排ガス浄化用触媒の助触媒として広く用いられている。また、 ＯＳＣを高めるためには比表面積を大きくすることが望ましいため、セリアは粉末状態として用いられている。
【０００３】
しかしながら、排ガス浄化用触媒は高温で使用されるので、高温における浄化活性が高いことが必要である。そのためセリアには、粉末として高比表面積をもつようにして用いた場合においても、高温での使用時に比表面積の低下が生じないこと、つまり耐熱性に優れていることが要求されている。
【０００４】
そこで従来より、セリアにジルコニアやセリウムを除く希土類元素の酸化物を固溶させることが提案されている。例えば特開平０４−０５５３１５号公報には、セリウム（Ｃｅ）の水溶性塩とジルコニウム（Ｚｒ）の水溶性塩の混合水溶液からセリア前駆体とジルコニア前駆体とを共沈させ、それを熱処理する酸化セリウム微粉体の製造方法が開示されている。この製造方法によれば、共沈物を熱処理することによりＣｅＯ２とＺｒＯ２は複合酸化物となり、互いに固溶した酸化物固溶体が生成する。
【０００５】
また特開平０９−２２１３０４号公報には、ＣｅとＺｒの金属塩が溶解した水溶液から酸化物前駆体を沈殿させる際に界面活性剤を添加しておくことで、結晶子の平均径が小さく高い固溶度となり、高い ＯＳＣが発現されるセリア−ジルコニア固溶体の製造方法が開示されている。
【０００６】
このように酸化物前駆体を沈殿させる際に界面活性剤を添加しておくことにより、界面活性剤のミセルの中に複数種の沈殿粒子が均一に取り込まれる。そしてミセル中で中和、凝集及び熟成が進行することによって、複数成分が均一に含まれ濃縮された小さな空間の中で固溶体粒子の生成が進行する。さらに、界面活性剤の分散効果により沈殿微粒子の分散性が向上し、偏析が小さくなって接触度合いが高まる。これらにより固溶度が高くなるとともに、結晶子の平均径を小さくすることができる。
【０００７】
さらに特表２００１−５２４９１８号公報には、金属塩の水溶液から酸化物前駆体を沈殿させる際に界面活性剤を添加しておくことで、粒子サイズ分布、細孔容積などを最適に調整するジルコニアあるいはセリア−ジルコニア固溶体などの製造方法が開示されている。
【０００８】
【特許文献１】特開平０４−０５５３１５号
【特許文献２】特開平０９−２２１３０４号
【特許文献３】特表２００１−５２４９１８号
【０００９】
【発明が解決しようとする課題】
ところが金属塩の水溶液から酸化物前駆体を沈殿させる際に界面活性剤を添加しておく方法では、得られる酸化物粉末の二次粒子径が小さくなるとともに細孔容積も小さくなる場合があり、触媒担体として用いた場合にその特性が十分に発現されないことがあった。
【００１０】
例えばハニカム基材に触媒担体粉末からコート層を形成し、そのコート層に貴金属などの触媒成分を担持した排ガス浄化用触媒においては、コート層中の下層部分の触媒成分が有効利用できないという問題がある。これは、排ガスがコート層を通過する際に下層まで拡散しにくいためであり、細孔容積が小さいことに起因していると考えられる。
【００１１】
本発明はこのような事情に鑑みてなされたものであり、大きな細孔容積をもち、触媒担体としてきわめて有用な金属酸化物とすることを主たる目的とする。
【００１２】
【課題を解決するための手段】
上記課題を解決する本発明の金属酸化物の特徴は、細孔径が ０．１μｍ以下の細孔の細孔容積が ０．２ｃｃ／ｇ以上であることにある。細孔径が ０．１μｍ以下の細孔の細孔容積が ０．３ｃｃ／ｇ以上であることが望ましい。
【００１３】
また、細孔径が０．０１μｍ以上かつ ０．１μｍ以下の細孔の細孔容積が ０．２ｃｃ／ｇ以上であることが好ましく、さらに細孔径が０．０１μｍ以上かつ０．０５μｍ以下の細孔の細孔容積が ０．１ｃｃ／ｇ以上であること、その細孔容積が、細孔径が０．０１μｍ以上かつ ０．１μｍ以下の細孔の細孔容積の７０％以上を占めることが望ましい。
【００１４】
そして上記金属酸化物を製造できる本発明の製造方法の特徴は、酸化物となる金属元素を含む化合物が溶解した水溶液にアルカリ性物質を添加することにより酸化物前駆体の沈殿物を得る第１工程と、沈殿物を洗浄する第２工程と、洗浄後の沈殿物を界面活性剤とともに水中で撹拌する第３工程と、第３工程後の沈殿物を焼成する第４工程と、を順次行うことにある。
【００１５】
本発明の製造方法において、界面活性剤は得られる金属酸化物粉末に対して２〜４０重量％となるように添加されることが望ましい。また金属元素はＺｒ又はＣｅとＺｒであり、本発明の金属酸化物はＺｒＯ２又はＣｅＯ２−ＺｒＯ２固溶体であることが望ましい。
【００１６】
また本発明の触媒の特徴は、本発明の金属酸化物に少なくとも一種類の貴金属を担持してなることにある。
【００１７】
【発明の実施の形態】
排ガス浄化用触媒の触媒担体として用いられている Ａｌ２Ｏ３、ＺｒＯ２、ＣｅＯ２−ＺｒＯ２固溶体など従来の金属酸化物では、細孔径が ０．１μｍ以下の細孔の細孔容積が０〜 ０．２ｃｃ／ｇと比較的小さな範囲にあった。そのためコート層におけるガス拡散性が低く、コート層の下層に担持されている触媒成分を有効利用することが困難であった。なお細孔容積とは、それぞれの細孔の合計容積をいう。また二次粒子は一次粒子が凝集してなるものであり、平均二次粒子径は金属酸化物の粉末の現実の平均粒子径に相当するものである。
【００１８】
そこで本発明の金属酸化物は、細孔径が ０．１μｍ以下の細孔の細孔容積が ０．２ｃｃ／ｇ以上としている。この金属酸化物の粉末からコート層を形成することにより、ガス拡散性に優れたコート層となり、下層においても触媒成分と排ガスとの接触機会が増大する。したがって触媒成分を有効に活用することができ、浄化能が向上する。
【００１９】
本発明の金属酸化物粉末において、細孔径が ０．１μｍ以下の細孔の細孔容積が０．２ｃｃ／ｇより小さい場合には、十分なガス拡散性が得られない。また平均二次粒子径があまり大きすぎると、脆くなりコート層とした場合に使用時の剥離などの不具合が生じる場合があるので、平均二次粒子径は３０μｍ以下であることが望ましい。
【００２０】
本発明の金属酸化物は、 Ａｌ２Ｏ３，ＺｒＯ２，ＴｉＯ２，ＳｉＯ２，ＣｅＯ２，あるいはこれらから選ばれる任意の複数種からなる複合酸化物とすることができる。例えばＺｒＯ２あるいはＣｅＯ２−ＺｒＯ２固溶体とすることが特に好ましい。ＺｒＯ２の場合には、例えばＲｈを担持した触媒とすることで、ガス拡散性が高いために水蒸気改質反応活性が大きく向上し、高い生成能をもつ水素生成触媒として利用することができる。またＣｅＯ２−ＺｒＯ２固溶体の場合には、ガス拡散性が高いために高い ＯＳＣが発現され、三元触媒などとしてきわめて有用である。
【００２１】
本発明の金属酸化物粉末を確実にかつ容易に製造できる本発明の製造方法では、先ず第１工程において、酸化物となる金属元素を含む化合物が溶解した水溶液にアルカリ性物質を添加することにより酸化物前駆体の沈殿物を形成する。
【００２２】
酸化物となる金属元素を含む化合物が溶解した水溶液としては、Ａｌ，Ｚｒ，Ｔｉ，Ｓｉ，Ｃｅなどの金属を含む水溶性化合物の水溶液を用いることができ、例えば金属がＣｅ又はＺｒの場合には、硝酸セリウム（ＩＩＩ）、硝酸セリウム（ＩＶ）アンモニウム、塩化セリウム（ＩＩＩ）、硫酸セリウム（ＩＩＩ）、硫酸セリウム（ＩＶ）、オキシ硝酸ジルコニウム、オキシ塩化ジルコニウムなどの水溶液を用いることができる。
【００２３】
またアルカリ性物質としては、水溶液としてアルカリ性を示すものであれば用いることができる。加熱時に容易に分離できるアンモニアが特に望ましい。しかしアルカリ金属の水酸化物などの他のアルカリ性物質であっても、水洗によって容易に除去することができるので用いることができる。このアルカリ性物質の添加は水溶液として添加することが望ましく、徐々に滴下してもよいし一度に全量を混合することもできる。なお沈殿物の偏析を防止するために、金属元素が溶解した水溶液を撹拌しながら添加することが望ましい。
【００２４】
ＣｅＯ２−ＺｒＯ２固溶体を製造する場合には、セリウムの価数に注意する必要がある。４価のセリウムの場合には、ＣｅＯ２はＺｒＯ２と比較的容易に固溶するので問題はないが、３価のセリウムの場合には、ＣｅＯ２はＺｒＯ２と固溶しにくいので、例えば水溶液中に過酸化水素を共存させることが望ましい。このようにすれば、セリウム（ＩＩＩ）が過酸化水素と錯体を作り酸化されてセリウム（ＩＶ）となるので、ＣｅＯ２をＺｒＯ２と固溶させやすくすることができる。
【００２５】
過酸化水素の添加量は、セリウムイオンの１／４以上であることが望ましい。過酸化水素の添加量がセリウムイオンの１／４未満であるとＣｅＯ２とＺｒＯ２の固溶が不十分となる。過酸化水素の過剰の添加は特に悪影響を及ぼさないが、経済的な面で不利となるのみでメリットはなく、セリウムイオンの１／２〜２倍の範囲にあることがより望ましい。なお、過酸化水素の添加時期は特に制限されず、アルカリ性物質の添加前でもよいし、同時あるいはそれより後に添加することもできる。また過酸化水素は後処理が不要となるので特に望ましい酸化剤であるが、場合によっては酸素ガスやオゾン、過塩素酸、過マンガン酸などの過酸化物など他の酸化剤を用いることもできる。
【００２６】
さらに、酸化物となる金属元素を含む化合物が溶解した水溶液を１０３ｓｅｃ−１以上、望ましくは１０４ｓｅｃ−１以上の高せん断速度で高速撹拌しながらアルカリ性物質を添加することも好ましい。中和生成物である沈殿微粒子中の成分は、ある程度の偏析が避けられないため、強力な撹拌によりこの偏析を均一にするとともに分散性を向上させることができる。例えばセリウム塩とジルコニウム塩の水溶液から共沈させる場合、両者の沈殿するｐＨが異なるため同種の沈殿粒子が集団になりやすい。そこで高せん断速度で高速撹拌することにより、同種の沈殿微粒子の集団が破壊され、ＣｅＯ２前駆体とＺｒＯ２前駆体の接触度合いが向上するため沈殿粒子がよく混合される。したがってＣｅＯ２−ＺｒＯ２固溶体の固溶度が向上するとともに結晶子の平均径を小さくすることができる。せん断速度が１０３ｓｅｃ−１未満では、固溶促進効果が十分でない。なお、せん断速度Ｖは、Ｖ＝ｖ／Ｄで表される。ここでｖは撹拌機のロータとステータの速度差（ｍ／ｓｅｃ）であり、Ｄはロータとステータの間隙（ｍ）である。
【００２７】
従来の共沈法においては、酸化物となる金属元素を含む化合物及びアルカリ性物質と、界面活性剤とが水溶液中で共存している。そのためアルカリ性物質添加時のｐＨ変化によって界面活性剤の性質が変化し、界面活性剤の添加効果が損なわれるという不具合があった。
【００２８】
そこで本発明の製造方法では、第２工程において酸化物前駆体の沈殿物を洗浄し、第３工程において洗浄後の沈殿物を界面活性剤とともに水中で撹拌している。第２工程における洗浄によって、酸化物前駆体からアルカリ性物質及び遊離酸などが洗い流されるため、第３工程においては界面活性剤はｐＨ変化に晒されない。したがって界面活性剤の添加効果が最大に発現され、第４工程における焼成によって細孔径が ０．１μｍ以下の細孔の細孔容積が ０．２ｃｃ／ｇ以上である金属酸化物を製造することができる。
【００２９】
界面活性剤の作用は明らかではないが、以下のように推察される。つまり、アルカリ性物質で中和したばかりの状態では、酸化物となる金属元素は数ｎｍ以下の粒径の非常に微細な水酸化物又は酸化物の状態で沈殿する。そして第２工程における洗浄中などに一次粒子の凝集がある程度進行して二次粒子となる。
【００３０】
第３工程における界面活性剤の添加により、界面活性剤のミセルの中にその二次粒子が取り込まれ、ミセル中で凝集及び熟成が進行することによって、濃縮された小さな空間の中で粒子の成長が進行する。さらに、界面活性剤の分散効果により二次粒子の分散性が向上する。これらの作用により、細孔径が ０．１μｍ以下の細孔の細孔容積が ０．２ｃｃ／ｇ以上である金属酸化物粉末を製造することができると考えられる。
【００３１】
第３工程における界面活性剤の添加量は、得られる金属酸化物粉末に対して２〜４０重量％となる範囲、すなわち重量比で金属酸化物粉末：界面活性剤＝９８〜６０：２〜４０の範囲が好ましい。界面活性剤の添加量が２重量％未満では添加した効果が小さく、４０重量％を超えて添加すると界面活性剤どうしの凝集によって酸化物前駆体の分散性が低下し、また第４工程における焼成時に界面活性剤の燃焼による発熱量が大きくなるため金属酸化物の凝集が生じて比表面積が小さくなってしまう。
【００３２】
なお第３工程における水の量は、第１工程における水の量と同程度であることが好ましいが、撹拌できる範囲であれば特に制限されない。また第３工程における撹拌速度は１０００ ｓｅｃ−１以上とすることが好ましく、１０〜３０℃の温度で５分間以上撹拌することが好ましい。撹拌による剪断力が大きすぎると発熱したり装置の消耗が激しくなり、剪断力が小さすぎると界面活性剤の分散状態が十分でない場合がある。また撹拌時の温度がこの範囲より低いと撹拌時間が長時間となり、この範囲より高い温度では発熱や装置の消耗が生じるようになる。
【００３３】
界面活性剤としては、陰イオン系、陽イオン系及び非イオン系などのいずれも用いることができるが、その中でも形成するミセルが内部に狭い空間を形成しうる形状、例えば球状ミセルを形成し易い界面活性剤が望ましい。また臨界ミセル濃度（ｃｍｃ）が０．１ｍｏｌ／リットル以下のものが望ましく、０．０１ｍｏｌ／リットル以下の界面活性剤が望ましい。なお臨界ミセル濃度（ｃｍｃ）とは、ある界面活性剤がミセルを形成する最低の濃度のことである。
【００３４】
これらの界面活性剤を例示すると、陰イオン性界面活性剤である、アルキルベンゼンスルホン酸及びその塩、αオレフィンスルホン酸及びその塩、アルキル硫酸エステル塩、アルキルエーテル硫酸エステル塩、フェニルエーテル硫酸エステル塩、メチルタウリン酸塩、スルホコハク酸塩、エーテル硫酸塩、アルキル硫酸塩、エーテルスルホン酸塩、飽和脂肪酸及びその塩、オレイン酸等の不飽和脂肪酸及びその塩、その他のカルボン酸、スルホン酸、硫酸、リン酸、フェノールの誘導体等；
非イオン性界面活性剤である、ポリオキシエチレンポリプロピレンアルキルエーテル、ポリオキシエチレンアルキルエーテル、ポリキシエチレンアルキルフェニルエーテル、ポリオキシエチレンポリスチリルフェニルエーテル、ポリオキシエチレンポリオキシポリプロピレンアルキルエーテル、ポリオキシエチレンポリオキシプロピレングリコール、グリコール，グリセリン，ソルビトール，マンニトール，ペンタエリスリトール，ショ糖などの多価アルコール、多価アルコールの脂肪酸部分エステル、多価アルコールのポリオキシエチレン脂肪酸部分エステル、多価アルコールのポリオキシエチレン脂肪酸エステル、ポリオキシエチレン化ヒマシ油、ポリグリセン脂肪酸エステル、脂肪酸ジエタノールアミド、ポリオキシエチレンアルキルアミン、トリエタノールアミン脂肪酸部分エステル、トリアルキルアミンオキサイド等；
陽イオン性界面活性剤である、脂肪酸第一アミン塩、脂肪酸第二アミン塩、脂肪酸第三アミン塩、テトラアルキルアンモニウム塩，トリアルキルベンジルアンモニウム塩，アルキルピロジニウム塩，２−アルキル−１−アルキル−１−ヒドロキシエチルイミダゾリニウム塩，Ｎ，Ｎ−ジアルキルモルホリニウム塩，ポリエチレンポリアミン，脂肪酸アミド塩等の第四吸アンモニウム塩等；
両イオン性界面活性剤である、ベタイン化合物等；から選ばれる少なくとも一種を用いることができる。
【００３５】
第４工程では、第３工程後の酸化物前駆体の沈殿物を焼成することにより、沈殿物中の金属元素を酸化物とする。この焼成雰囲気は、酸化雰囲気、還元雰囲気、中性雰囲気のいずれの雰囲気でもよい。沈殿物中の金属元素が酸化物となるのは、原料として使用した水溶液の水等に含まれる酸素が関与し、焼成時に沈殿物中の金属元素を酸化させるからである。したがって、還元雰囲気で焼成しても金属酸化物が得られる。なお焼成温度は １５０〜 ８００℃とすることが好ましい。焼成温度が １５０℃より低いと焼成に長時間必要となり、 ８００℃より高くなると比表面積が低下するようになる。
【００３６】
また第３工程と第４工程の間に、さらに沈殿物の洗浄工程を行うことも好ましい。これにより界面活性剤を除去することができ、焼成時における界面活性剤の燃焼による発熱を回避することができる。
【００３７】
そして本発明の触媒は、上記した本発明の金属酸化物粉末に少なくとも貴金属を担持してなることにある。貴金属としてはＰｔ，Ｒｈ，Ｐｄ，Ｉｒなどから選ばれる少なくとも一種であり、従来と同様に吸着担持法、含浸担持法などによって担持することができ、酸化触媒，水素生成触媒，三元触媒などとして利用することができる。またアルカリ金属，アルカリ土類金属，希土類金属から選ばれる少なくとも一種のＮＯｘ吸蔵材を貴金属とともに担持してＮＯｘ吸蔵還元型触媒とすることもできる。触媒体積１リットル当たりの貴金属の担持量は ０．１〜２０ｇの範囲が好ましく、ＮＯｘ吸蔵材の担持量は０．０５モル〜２モルの範囲が好ましい。
【００３８】
なお本発明の金属酸化物粉末から排ガス浄化用触媒を製造する場合において、先ずコート層を形成してから貴金属あるいはＮＯｘ吸蔵材などの触媒成分を担持してもよいし、金属酸化物粉末に予め触媒成分を担持した触媒粉末からコート層を形成することもできる。
【００３９】
【実施例】
以下、実施例及び比較例により本発明を具体的に説明する。
【００４０】
（実施例１）
第１工程：
３リットルのビーカ中において、硝酸セリウム水溶液４４２．２９ｇ（ＣｅＯ２として２８重量％）と、オキシ硝酸ジルコニウム水溶液 ６０１．３ｇ（ＺｒＯ２として１８重量％）と、３０％過酸化水素水 １９９．５ｇと、を１２００ｇのイオン交換水と混合し、プロペラ撹拌器で撹拌しながら、２５％アンモニア水溶液 ３１９．９ｇを添加し、酸化物前駆体の沈殿物を得た。
【００４１】
第２工程：
得られた沈殿物を遠心分離器にかけて上澄み液を捨て、これにイオン交換水を捨てた上澄み液を同量加えて撹拌し再び遠心分離器にかけた。この操作をさらに２回行うことにより、沈殿物を洗浄した。
【００４２】
第３工程：
最後に上澄み液を捨てた後の沈殿物を再び３リットルのビーカに移し、イオン交換水１８００ｇを加えてプロペラ撹拌器とホモジナイザを用いて撹拌した。そこへ陽イオン性界面活性剤（「アーマック」ライオン社製）５ｇと陰イオン性界面活性剤（「アーモフロー」ライオン社製）５ｇを加え、さらに５分間撹拌した。
【００４３】
この分散液を遠心分離器にかけ、第２工程と同様にして沈殿物を洗浄した。
【００４４】
第４工程：
最後に上澄み液を捨てた後の沈殿物を、脱脂炉を用い大気中にて ４００℃で５時間焼成し、さらに大気中 ７００℃で５時間焼成してＣｅＯ２−ＺｒＯ２固溶体粉末を調製した。
【００４５】
得られたＣｅＯ２−ＺｒＯ２固溶体粉末の、細孔径が ０．１μｍ以下の細孔の細孔容積は０．３ｃｃ／ｇであり、平均二次粒子径は６μｍであった。なお細孔容積は水銀ポロシメータにより測定し、平均二次粒子径はレーザー回折／散乱式粒度分布測定装置により測定した。
【００４６】
触媒化：
得られたＣｅＯ２−ＺｒＯ２固溶体粉末に、所定濃度のＰｔ−Ｐソルト水溶液の所定量を含浸させ、蒸発・乾固後大気中にて ３００℃で３時間焼成してＰｔを担持した。Ｐｔの担持量は１重量％である。このＰｔ担持ＣｅＯ２−ＺｒＯ２固溶体粉末とバインダとしての硝酸アルミニウム及びアルミナゾルとをイオン交換水と混合してスラリーを調製し、コージェライト製３５ｃｃハニカム基材（３ミル， ４００セル）にウォッシュコートし、 ５００℃で１時間焼成してコート層を形成した。コート量はハニカム基材１リットルあたり １５０ｇであり、Ｐｔの担持量はハニカム基材１リットルあたり １．５ｇである。
【００４７】
（比較例１）
３リットルのビーカ中において、硝酸セリウム水溶液４４２．２９ｇ（ＣｅＯ２として２８重量％）と、オキシ硝酸ジルコニウム水溶液 ６０１．３ｇ（ＺｒＯ２として１８重量％）と、３０％過酸化水素水 １９９．５ｇと、界面活性剤（「レオコン」ライオン社製）１２ｇを１２００ｇのイオン交換水と混合し、プロペラ撹拌器で撹拌しながら、２５％アンモニア水溶液 ３１９．９ｇを添加し、酸化物前駆体の沈殿物を得た。
【００４８】
得られた沈殿物を、洗浄することなく、脱脂炉を用い大気中にて ４００℃で５時間焼成し、さらに大気中 ７００℃で５時間焼成してＣｅＯ２−ＺｒＯ２固溶体粉末を調製した。
【００４９】
得られたＣｅＯ２−ＺｒＯ２固溶体粉末の細孔径が ０．１μｍ以下の細孔の細孔容積は０．０５ｃｃ／ｇであり、平均二次粒子径は８μｍであった。
【００５０】
このＣｅＯ２−ＺｒＯ２固溶体粉末を用いたこと以外は実施例１と同様にして、比較例１の触媒を調製した。
【００５１】
（実施例２）
第１工程：
３リットルのビーカ中において、オキシ硝酸ジルコニウム水溶液 ２７８ｇ（ＺｒＯ２として１８重量％）を１８００ｇのイオン交換水と混合し、プロペラ撹拌器で撹拌しながら、２５％アンモニア水溶液６７ｇを添加し、酸化物前駆体の沈殿物を得た。
【００５２】
第２工程：
得られた沈殿物を遠心分離器にかけて上澄み液を捨て、これにイオン交換水を捨てた上澄み液を同量加えて撹拌し再び遠心分離器にかけた。この操作をさらに２回行うことにより、沈殿物を洗浄した。
【００５３】
第３工程：
最後に上澄み液を捨てた後の沈殿物を再び３リットルのビーカに移し、イオン交換水１８００ｇを加えてプロペラ撹拌器とホモジナイザを用いて撹拌した。そこへ陰イオン性界面活性剤（「アーモフロー」ライオン社製）５ｇを加え、さらに５分間撹拌した。
【００５４】
この分散液を遠心分離器にかけ、第２工程と同様にして沈殿物を洗浄した。
【００５５】
第４工程：
最後に上澄み液を捨てた後の沈殿物を、脱脂炉を用い大気中にて ４００℃で５時間焼成し、さらに大気中 ８００℃で５時間焼成してＺｒＯ２粉末を調製した。
【００５６】
得られたＺｒＯ２粉末の細孔分布を水銀ポロシメータにより測定し、結果を図１に示す。また実施例１と同様に測定された平均二次粒子径は７μｍであった。
【００５７】
触媒化：
得られたＺｒＯ２粉末に、所定濃度の硝酸ロジウム水溶液の所定量を含浸させ、蒸発・乾固後大気中にて ３００℃で３時間焼成してＲｈを担持した。Ｒｈの担持量は１重量％である。このＰｔ担持ＺｒＯ２粉末とバインダとしての硝酸アルミニウム及びアルミナゾルとをイオン交換水と混合してスラリーを調製し、コージェライト製３５ｃｃハニカム基材（３ミル， ４００セル）にウォッシュコートし、 ５００℃で１時間焼成してコート層を形成した。コート量はハニカム基材１リットルあたり４０ｇであり、Ｒｈの担持量はハニカム基材１リットルあたり ０．４ｇである。
【００５８】
（比較例２）
３リットルのビーカ中において、オキシ硝酸ジルコニウム水溶液 ２７８ｇ（ＺｒＯ２として１８重量％）を１８００ｇのイオン交換水と混合し、プロペラ撹拌器で撹拌しながら、２５％アンモニア水溶液６７ｇを添加し、酸化物前駆体の沈殿物を得た。
【００５９】
得られた沈殿物を、洗浄することなく、脱脂炉を用い大気中にて ４００℃で５時間焼成し、さらに大気中 ８００℃で５時間焼成してＺｒＯ２粉末を調製した。
【００６０】
得られたＺｒＯ２粉末の細孔分布を水銀ポロシメータにより測定し、結果を図１に示す。図１における縦軸のＶは細孔径を意味する。また実施例１と同様に測定されたこのＺｒＯ２粉末の平均二次粒子径は８μｍであった。
【００６１】
このＺｒＯ２粉末を用いたこと以外は実施例２と同様にして、比較例２の触媒を調製した。
【００６２】
＜試験・評価＞
実施例１及び比較例１の触媒を評価装置に配置し、表１に示すモデルガスを、リッチガス１分間及びリーンガス４分間の条件で交互に繰り返し流しながら、 ９００℃で５時間保持するリッチリーン耐久試験を行った。全流量は２０Ｌ／分である。またこれとは別に、大気中にて ９００℃で５時間保持するエアー耐久試験を行った。
【００６３】
【表１】
各耐久試験後の各触媒について、表２に示すモデルガスを、リッチガス１秒間及びリーンガス１秒間の条件で交互に繰り返し全流量２０Ｌ／分で流しながら２０℃／分の速度で昇温し、その間のＨＣ，ＣＯ及びＮＯｘの浄化率を連続的に測定した。そして各有害成分の５０％が浄化される温度（Ｔ５０）を算出し、結果を図２及び図３に示す。なお図２及び図３における棒グラフの頂点の数字は、実際のＴ５０の値である。
【００６５】
【表２】
また実施例２及び比較例２の触媒を評価装置に配置し、表１に示したモデルガスを、リッチガス１分間及びリーンガス４分間の条件で交互に繰り返し流しながら、１０００℃で５時間保持するリッチリーン耐久試験を行った。全流量は２０Ｌ／分である。またこれとは別に、大気中にて ８５０℃で５時間保持するエアー耐久試験を行った。
【００６７】
各耐久試験後の各触媒について、表２に示したモデルガスを、リッチガス１秒間及びリーンガス１秒間の条件で交互に繰り返し全流量２０Ｌ／分で流しながら２０℃／分の速度で昇温し、その間のＨＣ，ＣＯ及びＮＯｘの浄化率を連続的に測定した。そして各有害成分の５０％が浄化される温度（Ｔ５０）を算出し、結果を図４及び図５に示す。なお図４及び図５における棒グラフの頂点の数字は、実際のＴ５０の値である。
【００６８】
図２及び図３より、実施例１の触媒は比較例１の触媒に比べて各耐久試験後にも低温域から高い浄化能を示し、これはＣｅＯ２−ＺｒＯ２粉末の細孔容積及び平均二次粒子径の差に起因していると考えられる。すなわち実施例１の触媒は、コート層のガス拡散性に優れているため、コート層の下層に担持されているＰｔも有効に利用されたと考えられる。
【００６９】
また図４及び図５より、実施例２の触媒は比較例２の触媒に比べて各耐久試験後にも低温域から高い浄化能を示し、これは図１に示すように実施例２の触媒の方が細孔容積が大きく、平均二次粒子径も大きいことに起因していると考えられる。すなわち実施例２の触媒は、コート層のガス拡散性に優れているため、コート層の下層に担持されているＲｈも有効に利用されたと考えられる。
【００７０】
（実施例３）
第１工程：
３リットルのビーカ中において、硝酸セリウム水溶液５８９．７１ｇ（ＣｅＯ２として２８重量％）と、オキシ硝酸ジルコニウム水溶液 ４３７．３ｇ（ＺｒＯ２として１８重量％）と、３０％過酸化水素水 １９９．５ｇと、界面活性剤（「レオコン」ライオン社製）１２ｇと、を１２００ｇのイオン交換水と混合し、プロペラ撹拌器及びホモジナイザで撹拌しながら、２５％アンモニア水溶液 ３４０ｇを添加し、酸化物前駆体の沈殿物を得た。
【００７１】
第２工程以下は実施例１と同様にして、本実施例のＣｅＯ２−ＺｒＯ２固溶体粉末を調製した。
【００７２】
得られたＣｅＯ２−ＺｒＯ２固溶体粉末の、細孔径が ０．１μｍ以下の細孔の細孔容積は０．３ｃｃ／ｇであり、平均二次粒子径は６μｍであった。なお細孔容積は水銀ポロシメータにより測定し、平均二次粒子径はレーザー回折／散乱式粒度分布測定装置により測定した。
【００７３】
（実施例４）
第１工程：
３リットルのビーカ中において、硝酸セリウム水溶液５８９．７１ｇ（ＣｅＯ２として２８重量％）と、オキシ硝酸ジルコニウム水溶液 ４３７．３ｇ（ＺｒＯ２として１８重量％）と、３０％過酸化水素水 １９９．５ｇと、３０％過酸化水素水 １９９．５ｇと、を１２００ｇのイオン交換水と混合し、２５％アンモニア水溶液３ｇを添加して、プロペラ撹拌器で撹拌した。これを １２０℃で２時間加圧熟成した。この溶液をプロペラ撹拌器で撹拌しながら、２５％アンモニア水溶液 ３４０ｇを添加し、酸化物前駆体の沈殿物を得た。
【００７４】
第２工程以下は実施例１と同様にして、本実施例のＣｅＯ２−ＺｒＯ２固溶体粉末を調製した。
【００７５】
得られたＣｅＯ２−ＺｒＯ２固溶体粉末の、細孔径が ０．１μｍ以下の細孔の細孔容積は０．２ｃｃ／ｇであり、平均二次粒子径は６μｍであった。なお細孔容積は水銀ポロシメータにより測定し、平均二次粒子径はレーザー回折／散乱式粒度分布測定装置により測定した。
【００７６】
＜試験・評価＞
実施例３及び実施例４のＣｅＯ２−ＺｒＯ２固溶体粉末の細孔分布を水銀ポロシメータにより測定し、結果を図６に示す。
【００７７】
図６より、実施例４のＣｅＯ２−ＺｒＯ２固溶体粉末の細孔分布は、実施例３に比べて微細な範囲に集中していることがわかる。これは、詳細な理由は不明であるが、微量のアンモニア水の添加と加圧熟成により、均一な核の生成が生じたことに起因していると考えられる。
【００７８】
そして図６より、実施例４のＣｅＯ２−ＺｒＯ２固溶体粉末は、細孔径が０．０１μｍ以上かつ０．０５μｍ以下の細孔の細孔容積が ０．１ｃｃ／ｇ以上であり、かつその細孔容積が、細孔径が０．０１μｍ以上かつ ０．１μｍ以下の細孔の細孔容積の７０％以上を占めていることが明らかである。
【００７９】
【発明の効果】
すなわち本発明の金属酸化物によれば、細孔容積と平均二次粒子径が従来より大きいためガス拡散性に優れ、本発明の触媒によれば、コート層の下層に担持されている触媒成分と排ガスとの接触機会が増し浄化能が向上する。
【図面の簡単な説明】
【図１】実施例２及び比較例２のＺｒＯ２粉末の細孔分布を示すグラフである。
【図２】実施例１及び比較例１の触媒のリッチリーン耐久試験後の５０％浄化温度を示すグラフである。
【図３】実施例１及び比較例１の触媒のエアー耐久試験後の５０％浄化温度を示すグラフである。
【図４】実施例２及び比較例２の触媒のリッチリーン耐久試験後の５０％浄化温度を示すグラフである。
【図５】実施例２及び比較例２の触媒のエアー耐久試験後の５０％浄化温度を
【図６】実施例３及び実施例４のＣｅＯ２−ＺｒＯ２固溶体粉末の細孔分布を示すグラフである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a metal oxide used as a catalyst carrier for an exhaust gas purifying catalyst of an automobile, a method for producing the same, and a catalyst. In addition, the metal oxide of the present invention can also be used as a catalyst carrier for a diesel particulate oxidation catalyst, a solid electrolyte, an electrode material, ceramic dispersion strengthened particles, a material for ultraviolet shielding, and the like.
[0002]
[Prior art]
Since ceria has oxygen storage / release capability (OSC), it is widely used as a promoter of an exhaust gas purifying catalyst for purifying exhaust gas from an internal combustion engine. Further, since it is desirable to increase the specific surface area in order to increase OSC, ceria is used in a powder state.
[0003]
However, since the exhaust gas purifying catalyst is used at a high temperature, it is necessary to have a high purifying activity at a high temperature. Therefore, even when ceria is used as a powder having a high specific surface area, it is required that the specific surface area does not decrease when used at a high temperature, that is, it is required to have excellent heat resistance.
[0004]
Therefore, conventionally, it has been proposed to form a solid solution of an oxide of a rare earth element other than zirconia and cerium in ceria. For example, Japanese Patent Application Laid-Open No. 04-055315 discloses that a ceria precursor and a zirconia precursor are coprecipitated from a mixed aqueous solution of a water-soluble salt of cerium (Ce) and a water-soluble salt of zirconium (Zr), and the resultant is subjected to heat treatment. A method for producing cerium fine powder is disclosed. According to this manufacturing method, CeO is heat-treated to form CeO. 2 And ZrO 2 Becomes a composite oxide, and an oxide solid solution that forms a solid solution with each other is generated.
[0005]
Japanese Patent Application Laid-Open No. 09-221304 discloses that a surfactant is added when an oxide precursor is precipitated from an aqueous solution in which metal salts of Ce and Zr are dissolved, so that the average diameter of crystallites is small and high. There is disclosed a method for producing a ceria-zirconia solid solution in which solid solubility is obtained and high OSC is expressed.
[0006]
By adding a surfactant when precipitating the oxide precursor in this manner, a plurality of types of precipitated particles are uniformly taken into micelles of the surfactant. Then, as neutralization, aggregation and aging progress in the micelles, the formation of solid solution particles proceeds in a small space in which a plurality of components are uniformly contained and concentrated. Furthermore, the dispersing effect of the surfactant improves the dispersibility of the precipitated fine particles, reduces segregation, and increases the degree of contact. As a result, the solid solubility is increased, and the average diameter of crystallites can be reduced.
[0007]
Further, Japanese Patent Application Laid-Open No. 2001-524918 discloses a zirconia in which a surfactant is added at the time of precipitating an oxide precursor from an aqueous solution of a metal salt to thereby optimally adjust a particle size distribution, a pore volume, and the like. Alternatively, a method for producing a ceria-zirconia solid solution or the like is disclosed.
[0008]
[Patent Document 1] JP-A-04-055315
[Patent Document 2] JP-A-09-221304
[Patent Document 3] JP-T-2001-524918
[0009]
[Problems to be solved by the invention]
However, in the method of adding a surfactant when precipitating the oxide precursor from the aqueous solution of the metal salt, the resulting oxide powder may have a small secondary particle diameter and a small pore volume, When used as a catalyst carrier, its properties may not be sufficiently exhibited.
[0010]
For example, in a catalyst for purifying exhaust gas in which a coat layer is formed from a catalyst carrier powder on a honeycomb substrate and a catalyst component such as a noble metal is supported on the coat layer, there is a problem that a catalyst component in a lower layer portion in the coat layer cannot be effectively used. is there. This is because the exhaust gas hardly diffuses to the lower layer when passing through the coat layer, and is considered to be due to the small pore volume.
[0011]
The present invention has been made in view of such circumstances, and a main object of the present invention is to provide a metal oxide having a large pore volume and extremely useful as a catalyst carrier.
[0012]
[Means for Solving the Problems]
A feature of the metal oxide of the present invention that solves the above-mentioned problem is that the pore volume of pores having a pore diameter of 0.1 μm or less is 0.2 cc / g or more. The pore volume of pores having a pore diameter of 0.1 μm or less is desirably 0.3 cc / g or more.
[0013]
Further, the pore volume of pores having a pore diameter of 0.01 μm or more and 0.1 μm or less is preferably 0.2 cc / g or more, and pores having a pore diameter of 0.01 μm or more and 0.05 μm or less are preferable. Is preferably 0.1 cc / g or more, and the pore volume occupies 70% or more of the pore volume of pores having a pore diameter of 0.01 μm or more and 0.1 μm or less.
[0014]
The manufacturing method of the present invention capable of manufacturing the above metal oxide is characterized in that a first step of obtaining a precipitate of an oxide precursor by adding an alkaline substance to an aqueous solution in which a compound containing a metal element to be an oxide is dissolved. And a second step of washing the precipitate, a third step of stirring the washed precipitate together with a surfactant in water, and a fourth step of firing the precipitate after the third step. It is in.
[0015]
In the production method of the present invention, the surfactant is desirably added so as to be 2 to 40% by weight based on the obtained metal oxide powder. The metal element is Zr or Ce and Zr, and the metal oxide of the present invention is ZrO. 2 Or CeO 2 -ZrO 2 Desirably, it is a solid solution.
[0016]
A feature of the catalyst of the present invention resides in that at least one noble metal is supported on the metal oxide of the present invention.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Al used as a catalyst carrier for exhaust gas purification catalysts 2 O 3 , ZrO 2 , CeO 2 -ZrO 2 In a conventional metal oxide such as a solid solution, the pore volume of pores having a pore diameter of 0.1 μm or less was in a relatively small range of 0 to 0.2 cc / g. Therefore, gas diffusivity in the coat layer is low, and it has been difficult to effectively use the catalyst component carried in the lower layer of the coat layer. The pore volume refers to the total volume of each pore. The secondary particles are formed by aggregating the primary particles, and the average secondary particle diameter corresponds to the actual average particle diameter of the metal oxide powder.
[0018]
Therefore, in the metal oxide of the present invention, the pore volume of pores having a pore diameter of 0.1 μm or less is 0.2 cc / g or more. By forming a coat layer from this metal oxide powder, a coat layer having excellent gas diffusibility is obtained, and even in the lower layer, the chance of contact between the catalyst component and the exhaust gas increases. Therefore, the catalyst component can be effectively used, and the purification ability is improved.
[0019]
In the metal oxide powder of the present invention, if the pore volume of pores having a pore diameter of 0.1 μm or less is smaller than 0.2 cc / g, sufficient gas diffusivity cannot be obtained. Further, if the average secondary particle size is too large, the coating layer becomes brittle and problems such as peeling during use may occur when used as a coating layer. Therefore, the average secondary particle size is desirably 30 μm or less.
[0020]
The metal oxide of the present invention comprises Al 2 O 3 , ZrO 2 , TiO 2 , SiO 2 , CeO 2 Or a composite oxide composed of a plurality of arbitrary kinds selected from these. For example, ZrO 2 Or CeO 2 -ZrO 2 Particularly preferred is a solid solution. ZrO 2 In the case of, for example, a catalyst supporting Rh can be used as a hydrogen generation catalyst having high gas diffusibility, which greatly enhances steam reforming reaction activity and has high production ability. Also CeO 2 -ZrO 2 In the case of a solid solution, high OSC is exhibited due to high gas diffusivity, and it is extremely useful as a three-way catalyst or the like.
[0021]
In the production method of the present invention, which can produce the metal oxide powder of the present invention reliably and easily, in the first step, the oxidation is carried out by adding an alkaline substance to an aqueous solution in which a compound containing a metal element to be an oxide is dissolved. A precipitate of the product precursor is formed.
[0022]
As the aqueous solution in which the compound containing the metal element to be an oxide is dissolved, an aqueous solution of a water-soluble compound containing a metal such as Al, Zr, Ti, Si, or Ce can be used. For example, when the metal is Ce or Zr, An aqueous solution of cerium (III) nitrate, ammonium cerium (IV) nitrate, cerium (III) chloride, cerium (III) sulfate, cerium (IV) sulfate, zirconium oxynitrate, zirconium oxychloride, or the like can be used.
[0023]
In addition, as the alkaline substance, any substance that exhibits alkaline as an aqueous solution can be used. Ammonia, which can be easily separated on heating, is particularly desirable. However, other alkaline substances such as hydroxides of alkali metals can be used because they can be easily removed by washing with water. The addition of the alkaline substance is desirably performed as an aqueous solution, and the alkaline substance may be added gradually or may be mixed at once. In order to prevent segregation of the precipitate, it is desirable to add the aqueous solution in which the metal element is dissolved with stirring.
[0024]
CeO 2 -ZrO 2 When producing a solid solution, attention must be paid to the valence of cerium. In the case of tetravalent cerium, CeO 2 Is ZrO 2 There is no problem because it is relatively easy to form a solid solution with cerium. 2 Is ZrO 2 For example, it is desirable that hydrogen peroxide coexist in an aqueous solution. In this way, cerium (III) forms a complex with hydrogen peroxide and is oxidized to cerium (IV), so that CeO 2 To ZrO 2 And a solid solution can be easily formed.
[0025]
It is desirable that the amount of hydrogen peroxide added be 1/4 or more of the cerium ion. If the amount of hydrogen peroxide added is less than 1/4 of the cerium ion, CeO 2 And ZrO 2 Is insufficiently dissolved. Excessive addition of hydrogen peroxide does not have any particular adverse effect, but is only disadvantageous in terms of economy and has no merit, and is more preferably in the range of 1/2 to 2 times the cerium ion. The timing of adding hydrogen peroxide is not particularly limited, and the hydrogen peroxide may be added before the addition of the alkaline substance, or simultaneously or later. Hydrogen peroxide is a particularly desirable oxidizing agent since post-treatment is unnecessary, but in some cases, other oxidizing agents such as oxygen gas and peroxides such as ozone, perchloric acid, and permanganic acid can be used. .
[0026]
Further, an aqueous solution in which a compound containing a metal element to be an oxide is dissolved is dissolved in 10 3 sec -1 As described above, preferably 10 4 sec -1 It is also preferable to add the alkaline substance while stirring at high speed at the above high shear rate. Since a certain amount of segregation is inevitable for the components in the precipitated fine particles, which are the neutralization products, the segregation can be made uniform and the dispersibility can be improved by vigorous stirring. For example, when coprecipitating from an aqueous solution of a cerium salt and a zirconium salt, the precipitated particles of the same type tend to form a group because of the different pH of the two. Therefore, by high-speed stirring at a high shear rate, a group of the same type of precipitated fine particles is destroyed and CeO 2 Precursor and ZrO 2 Precipitated particles are well mixed because the degree of contact of the precursor is improved. Therefore CeO 2 -ZrO 2 The solid solubility of the solid solution is improved, and the average diameter of crystallites can be reduced. Shear rate is 10 3 sec -1 If it is less than 3, the solid solution promoting effect is not sufficient. Note that the shear rate V is represented by V = v / D. Here, v is the speed difference (m / sec) between the rotor and the stator of the stirrer, and D is the gap (m) between the rotor and the stator.
[0027]
In a conventional coprecipitation method, a compound containing a metal element to be an oxide and an alkaline substance, and a surfactant coexist in an aqueous solution. Therefore, there is a problem that the properties of the surfactant change due to the pH change at the time of adding the alkaline substance, and the effect of adding the surfactant is impaired.
[0028]
Therefore, in the production method of the present invention, the precipitate of the oxide precursor is washed in the second step, and the washed precipitate is stirred in water with the surfactant in the third step. Since the alkaline substance and the free acid are washed out of the oxide precursor by the washing in the second step, the surfactant is not exposed to a pH change in the third step. Therefore, the effect of the addition of the surfactant is maximized, and the baking in the fourth step can produce a metal oxide having a pore volume of 0.1 μm or less and a pore volume of 0.2 cc / g or more. it can.
[0029]
Although the action of the surfactant is not clear, it is presumed as follows. That is, in the state just neutralized with the alkaline substance, the metal element to be an oxide precipitates in a state of a very fine hydroxide or oxide having a particle size of several nm or less. Then, during the washing in the second step or the like, the aggregation of the primary particles progresses to some extent to become secondary particles.
[0030]
By the addition of the surfactant in the third step, the secondary particles are taken into the micelles of the surfactant, and the aggregation and ripening progress in the micelles, whereby the particles grow in the concentrated small space. Progresses. Further, the dispersibility of the secondary particles is improved by the dispersing effect of the surfactant. It is considered that by these actions, it is possible to produce a metal oxide powder in which the pore volume of pores having a pore diameter of 0.1 μm or less is 0.2 cc / g or more.
[0031]
The amount of the surfactant added in the third step is in the range of 2 to 40% by weight based on the obtained metal oxide powder, that is, metal oxide powder: surfactant = 98 to 60: 2 to 40 by weight ratio. Is preferable. If the amount of the surfactant is less than 2% by weight, the effect of the addition is small. If the amount exceeds 40% by weight, the dispersibility of the oxide precursor is reduced due to aggregation of the surfactants, and the calcination in the fourth step In some cases, the calorific value generated by the combustion of the surfactant increases, so that aggregation of the metal oxide occurs and the specific surface area decreases.
[0032]
The amount of water in the third step is preferably about the same as the amount of water in the first step, but is not particularly limited as long as it can be stirred. The stirring speed in the third step is 1000 sec. -1 It is preferable to stir at a temperature of 10 to 30 ° C. for 5 minutes or more. If the shearing force due to the stirring is too large, heat is generated or the device is greatly consumed. If the shearing force is too small, the surfactant may not be sufficiently dispersed. If the temperature at the time of stirring is lower than this range, the stirring time is long, and if the temperature is higher than this range, heat generation and device consumption occur.
[0033]
As the surfactant, any of anionic, cationic and nonionic surfactants can be used, and among them, micelles formed therein can easily form narrow spaces inside, for example, spherical micelles are easily formed. Surfactants are desirable. Further, those having a critical micelle concentration (cmc) of 0.1 mol / liter or less are desirable, and surfactants of 0.01 mol / liter or less are desirable. The critical micelle concentration (cmc) is the lowest concentration at which a certain surfactant forms micelles.
[0034]
Illustrative examples of these surfactants are anionic surfactants, alkylbenzenesulfonic acid and salts thereof, α-olefinsulfonic acid and salts thereof, alkyl sulfate salts, alkyl ether sulfate salts, phenyl ether sulfate salts, Methyl taurate, sulfosuccinate, ether sulfate, alkyl sulfate, ether sulfonate, saturated fatty acid and its salt, unsaturated fatty acid such as oleic acid and its salt, other carboxylic acid, sulfonic acid, sulfuric acid, phosphorus Derivatives of acids and phenols;
Non-ionic surfactants such as polyoxyethylene polypropylene alkyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene polystyryl phenyl ether, polyoxyethylene polyoxy polypropylene alkyl ether, and polyoxyethylene poly Polyhydric alcohols such as oxypropylene glycol, glycol, glycerin, sorbitol, mannitol, pentaerythritol, sucrose, fatty acid partial esters of polyhydric alcohols, polyoxyethylene fatty acid partial esters of polyhydric alcohols, polyoxyethylene fatty acids of polyhydric alcohols Ester, polyoxyethylated castor oil, polyglycene fatty acid ester, fatty acid diethanolamide, polyoxyethylene alkyl Min, triethanolamine fatty acid partial esters, trialkylamine oxide and the like;
Fatty acid primary amine salt, fatty acid secondary amine salt, fatty acid tertiary amine salt, tetraalkylammonium salt, trialkylbenzylammonium salt, alkylpyridinium salt, 2-alkyl-1-, which is a cationic surfactant Quaternary ammonium salts such as alkyl-1-hydroxyethylimidazolinium salts, N, N-dialkylmorpholinium salts, polyethylene polyamines and fatty acid amide salts;
At least one selected from betaine compounds and the like, which are amphoteric surfactants, can be used.
[0035]
In the fourth step, the precipitate of the oxide precursor after the third step is calcined to convert the metal element in the precipitate into an oxide. This firing atmosphere may be any of an oxidizing atmosphere, a reducing atmosphere, and a neutral atmosphere. The reason why the metal element in the precipitate becomes an oxide is that oxygen contained in water or the like of the aqueous solution used as a raw material participates and oxidizes the metal element in the precipitate during firing. Therefore, a metal oxide can be obtained even when firing in a reducing atmosphere. The firing temperature is preferably from 150 to 800 ° C. If the firing temperature is lower than 150 ° C., it takes a long time for firing, and if it is higher than 800 ° C., the specific surface area decreases.
[0036]
It is also preferable to further perform a washing step of the precipitate between the third step and the fourth step. As a result, the surfactant can be removed, and heat generation due to combustion of the surfactant during firing can be avoided.
[0037]
And the catalyst of the present invention consists in carrying at least a noble metal on the above-mentioned metal oxide powder of the present invention. The noble metal is at least one selected from Pt, Rh, Pd, Ir, and the like, and can be supported by an adsorption supporting method, an impregnating supporting method, or the like as in the related art, and can be used as an oxidation catalyst, a hydrogen generation catalyst, a three-way catalyst, or the like. Can be used. At least one type of NO selected from alkali metals, alkaline earth metals, and rare earth metals x NO by supporting occlusion material with precious metal x An occlusion reduction type catalyst can also be used. The amount of the noble metal supported per liter of catalyst volume is preferably in the range of 0.1 to 20 g. x The loading amount of the occluding material is preferably in the range of 0.05 mol to 2 mol.
[0038]
In the case of producing an exhaust gas purifying catalyst from the metal oxide powder of the present invention, first, a coat layer is formed and then a noble metal or NO x A catalyst component such as an occluding material may be supported, or a coat layer may be formed from a catalyst powder in which a catalyst component is previously supported on a metal oxide powder.
[0039]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
[0040]
(Example 1)
First step:
In a 3 liter beaker, 442.29 g of cerium nitrate aqueous solution (CeO 2 28% by weight) and 601.3 g of an aqueous zirconium oxynitrate solution (ZrO 2 189.5% by weight) and 199.5 g of 30% aqueous hydrogen peroxide were mixed with 1200 g of ion-exchanged water, and while stirring with a propeller stirrer, 319.9 g of a 25% aqueous ammonia solution was added, and oxide precursor was added. A body precipitate was obtained.
[0041]
Second step:
The obtained precipitate was centrifuged to discard the supernatant, and the same amount of the supernatant discarded with the ion-exchanged water was added thereto, followed by stirring and centrifugation again. This operation was performed twice more to wash the precipitate.
[0042]
Third step:
Finally, the precipitate after discarding the supernatant was transferred again to a 3 liter beaker, and 1800 g of ion-exchanged water was added thereto, followed by stirring using a propeller stirrer and a homogenizer. Thereto, 5 g of a cationic surfactant (manufactured by "Armac" Lion) and 5 g of an anionic surfactant (manufactured by "Armoflow" Lion) were added, and the mixture was further stirred for 5 minutes.
[0043]
This dispersion was centrifuged, and the precipitate was washed in the same manner as in the second step.
[0044]
Fourth step:
Finally, the sediment after discarding the supernatant liquid is calcined at 400 ° C. for 5 hours in the air using a degreasing furnace, and further calcined at 700 ° C. for 5 hours in the air. 2 -ZrO 2 A solid solution powder was prepared.
[0045]
CeO obtained 2 -ZrO 2 The pore volume of pores having a pore diameter of 0.1 μm or less in the solid solution powder was 0.3 cc / g, and the average secondary particle diameter was 6 μm. The pore volume was measured by a mercury porosimeter, and the average secondary particle diameter was measured by a laser diffraction / scattering particle size distribution analyzer.
[0046]
Catalysis:
CeO obtained 2 -ZrO 2 The solid solution powder was impregnated with a predetermined amount of a Pt-P salt aqueous solution having a predetermined concentration, evaporated and dried, and then fired at 300 ° C. for 3 hours in the air to carry Pt. The supported amount of Pt is 1% by weight. This Pt-supported CeO 2 -ZrO 2 A slurry is prepared by mixing the solid solution powder and aluminum nitrate and alumina sol as a binder with ion-exchanged water, wash-coated on a cordierite 35 cc honeycomb substrate (3 mil, 400 cells), and baked at 500 ° C. for 1 hour. To form a coat layer. The coating amount was 150 g per liter of the honeycomb substrate, and the amount of Pt carried was 1.5 g per liter of the honeycomb substrate.
[0047]
(Comparative Example 1)
In a 3 liter beaker, 442.29 g of cerium nitrate aqueous solution (CeO 2 28% by weight) and 601.3 g of an aqueous zirconium oxynitrate solution (ZrO 2 189.5% by weight), 199.5 g of 30% aqueous hydrogen peroxide, and 12 g of a surfactant (manufactured by "Leocon Lion") with 1200 g of ion-exchanged water, and stirring with a propeller stirrer, 25% An aqueous ammonia solution (319.9 g) was added to obtain a precipitate of an oxide precursor.
[0048]
The obtained precipitate is calcined at 400 ° C. for 5 hours in the air using a degreasing furnace without washing, and further calcined at 700 ° C. for 5 hours in the air to obtain CeO. 2 -ZrO 2 A solid solution powder was prepared.
[0049]
CeO obtained 2 -ZrO 2 The pore volume of the solid solution powder having a pore diameter of 0.1 μm or less was 0.05 cc / g, and the average secondary particle diameter was 8 μm.
[0050]
This CeO 2 -ZrO 2 A catalyst of Comparative Example 1 was prepared in the same manner as in Example 1 except that a solid solution powder was used.
[0051]
(Example 2)
First step:
In a 3 liter beaker, 278 g of an aqueous solution of zirconium oxynitrate (ZrO 2 Was mixed with 1800 g of ion-exchanged water, and 67 g of a 25% aqueous ammonia solution was added while stirring with a propeller stirrer to obtain a precipitate of an oxide precursor.
[0052]
Second step:
The obtained precipitate was centrifuged to discard the supernatant, and the same amount of the supernatant discarded with the ion-exchanged water was added thereto, followed by stirring and centrifugation again. This operation was performed twice more to wash the precipitate.
[0053]
Third step:
Finally, the precipitate after discarding the supernatant was transferred again to a 3 liter beaker, and 1800 g of ion-exchanged water was added thereto, followed by stirring using a propeller stirrer and a homogenizer. 5 g of an anionic surfactant ("Armoflow" manufactured by Lion Corporation) was added thereto, and the mixture was further stirred for 5 minutes.
[0054]
This dispersion was centrifuged, and the precipitate was washed in the same manner as in the second step.
[0055]
Fourth step:
Finally, the sediment after discarding the supernatant is calcined at 400 ° C. for 5 hours in the air using a degreasing furnace, and further calcined at 800 ° C. for 5 hours in the air. 2 A powder was prepared.
[0056]
ZrO obtained 2 The pore distribution of the powder was measured by a mercury porosimeter, and the results are shown in FIG. The average secondary particle diameter measured in the same manner as in Example 1 was 7 μm.
[0057]
Catalysis:
ZrO obtained 2 The powder was impregnated with a predetermined amount of a rhodium nitrate aqueous solution having a predetermined concentration, evaporated and dried, and then baked in the air at 300 ° C. for 3 hours to carry Rh. The supported amount of Rh is 1% by weight. This Pt-supported ZrO 2 A slurry is prepared by mixing powder and aluminum nitrate and alumina sol as a binder with ion-exchanged water, wash-coated on a cordierite 35 cc honeycomb substrate (3 mil, 400 cells), and baked at 500 ° C. for 1 hour. A coat layer was formed. The amount of coating was 40 g per liter of the honeycomb substrate, and the amount of Rh supported was 0.4 g per liter of the honeycomb substrate.
[0058]
(Comparative Example 2)
In a 3 liter beaker, 278 g of an aqueous solution of zirconium oxynitrate (ZrO 2 Was mixed with 1800 g of ion-exchanged water, and 67 g of a 25% aqueous ammonia solution was added while stirring with a propeller stirrer to obtain a precipitate of an oxide precursor.
[0059]
The obtained precipitate is calcined at 400 ° C. for 5 hours in the air using a degreasing furnace without washing, and further calcined at 800 ° C. for 5 hours in the air. 2 A powder was prepared.
[0060]
ZrO obtained 2 The pore distribution of the powder was measured by a mercury porosimeter, and the results are shown in FIG. V on the vertical axis in FIG. 1 means the pore diameter. The ZrO measured in the same manner as in Example 1 2 The average secondary particle diameter of the powder was 8 μm.
[0061]
This ZrO 2 A catalyst of Comparative Example 2 was prepared in the same manner as in Example 2 except that powder was used.
[0062]
<Test / Evaluation>
The catalysts of Example 1 and Comparative Example 1 were placed in an evaluation device, and the model gas shown in Table 1 was alternately and repeatedly flown under a condition of rich gas of 1 minute and lean gas of 4 minutes, and was held at 900 ° C. for 5 hours. The test was performed. The total flow is 20 L / min. Separately from this, an air durability test was performed in which the sample was kept at 900 ° C. for 5 hours in the atmosphere.
[0063]
[Table 1]
For each catalyst after each durability test, the temperature of the model gas shown in Table 2 was raised at a rate of 20 ° C./min while flowing at a total flow rate of 20 L / min alternately under the conditions of rich gas for 1 second and lean gas for 1 second. HC, CO and NO x Was continuously measured. Then, the temperature at which 50% of each harmful component is purified (T 50 ) Was calculated, and the results are shown in FIGS. Note that the numbers at the vertices of the bar graphs in FIGS. 50 Is the value of
[0065]
[Table 2]
In addition, the catalysts of Example 2 and Comparative Example 2 were placed in an evaluation device, and the model gas shown in Table 1 was held at 1000 ° C. for 5 hours while alternately and repeatedly flowing under the conditions of a rich gas of 1 minute and a lean gas of 4 minutes. A lean durability test was performed. The total flow is 20 L / min. Separately, an air durability test was performed in which the sample was kept at 850 ° C. for 5 hours in the atmosphere.
[0067]
For each catalyst after each endurance test, the temperature of the model gas shown in Table 2 was raised at a rate of 20 ° C./min while flowing at a total flow rate of 20 L / min alternately under the conditions of rich gas for 1 second and lean gas for 1 second. HC, CO and NO during that x Was continuously measured. Then, the temperature at which 50% of each harmful component is purified (T 50 ) Was calculated, and the results are shown in FIGS. Note that the numbers at the vertices of the bar graphs in FIGS. 50 Is the value of
[0068]
2 and 3, the catalyst of Example 1 shows higher purification ability from a low temperature range even after each endurance test than the catalyst of Comparative Example 1, 2 -ZrO 2 It is thought to be due to the difference between the pore volume of the powder and the average secondary particle size. That is, since the catalyst of Example 1 was excellent in gas diffusivity of the coat layer, it is considered that Pt carried on the lower layer of the coat layer was also effectively used.
[0069]
4 and FIG. 5, the catalyst of Example 2 shows higher purification ability from a low temperature range even after each endurance test than the catalyst of Comparative Example 2, which is the same as that of the catalyst of Example 2 as shown in FIG. This is thought to be due to the larger pore volume and the larger average secondary particle diameter. That is, since the catalyst of Example 2 was excellent in gas diffusivity of the coat layer, it is considered that Rh supported on the lower layer of the coat layer was also effectively used.
[0070]
(Example 3)
First step:
In a 3 liter beaker, 589.71 g of cerium nitrate aqueous solution (CeO 2 287.3% by weight) and 437.3 g of an aqueous solution of zirconium oxynitrate (ZrO 2 18% by weight), 199.5 g of a 30% hydrogen peroxide solution, and 12 g of a surfactant (manufactured by "Leocon Lion") were mixed with 1200 g of ion-exchanged water, and stirred with a propeller stirrer and a homogenizer. While adding 340 g of a 25% aqueous ammonia solution, a precipitate of an oxide precursor was obtained.
[0071]
The second step and subsequent steps are performed in the same manner as in the first embodiment, and the CeO of the present embodiment is used. 2 -ZrO 2 A solid solution powder was prepared.
[0072]
CeO obtained 2 -ZrO 2 The pore volume of pores having a pore diameter of 0.1 μm or less in the solid solution powder was 0.3 cc / g, and the average secondary particle diameter was 6 μm. The pore volume was measured by a mercury porosimeter, and the average secondary particle diameter was measured by a laser diffraction / scattering particle size distribution analyzer.
[0073]
(Example 4)
First step:
In a 3 liter beaker, 589.71 g of cerium nitrate aqueous solution (CeO 2 287.3% by weight) and 437.3 g of an aqueous solution of zirconium oxynitrate (ZrO 2 18% by weight), 199.5 g of a 30% aqueous hydrogen peroxide solution and 199.5 g of a 30% aqueous hydrogen peroxide solution were mixed with 1200 g of ion-exchanged water, and 3 g of a 25% aqueous ammonia solution was added thereto. Stir with a stirrer. This was press-aged at 120 ° C. for 2 hours. While stirring this solution with a propeller stirrer, 340 g of a 25% aqueous ammonia solution was added to obtain a precipitate of an oxide precursor.
[0074]
The second step and subsequent steps are performed in the same manner as in the first embodiment, and the CeO of the present embodiment is used. 2 -ZrO 2 A solid solution powder was prepared.
[0075]
CeO obtained 2 -ZrO 2 In the solid solution powder, the pore volume of pores having a pore diameter of 0.1 μm or less was 0.2 cc / g, and the average secondary particle diameter was 6 μm. The pore volume was measured by a mercury porosimeter, and the average secondary particle diameter was measured by a laser diffraction / scattering particle size distribution analyzer.
[0076]
<Test / Evaluation>
CeO of Example 3 and Example 4 2 -ZrO 2 The pore distribution of the solid solution powder was measured by a mercury porosimeter, and the results are shown in FIG.
[0077]
FIG. 6 shows that CeO of Example 4 was used. 2 -ZrO 2 It can be seen that the pore distribution of the solid solution powder is concentrated in a finer range than in Example 3. Although the detailed reason is unknown, it is considered that uniform nucleation was caused by addition of a small amount of aqueous ammonia and aging under pressure.
[0078]
From FIG. 6, the CeO of Example 4 was used. 2 -ZrO 2 In the solid solution powder, the pore volume of pores having a pore diameter of 0.01 μm or more and 0.05 μm or less is 0.1 cc / g or more, and the pore volume is 0.01 μm or more and 0.1 μm or less. It is clear that the pores of 1 μm or less occupy 70% or more of the pore volume.
[0079]
【The invention's effect】
That is, according to the metal oxide of the present invention, the pore volume and the average secondary particle diameter are larger than before, so that the gas diffusion property is excellent. According to the catalyst of the present invention, the catalyst component supported on the lower layer of the coat layer The chance of contact between the gas and the exhaust gas increases, and the purification performance improves.
[Brief description of the drawings]
FIG. 1 shows ZrO of Example 2 and Comparative Example 2. 2 3 is a graph showing a pore distribution of a powder.
FIG. 2 is a graph showing 50% purification temperatures of catalysts of Example 1 and Comparative Example 1 after a rich lean durability test.
FIG. 3 is a graph showing the 50% purification temperatures of the catalysts of Example 1 and Comparative Example 1 after an air durability test.
FIG. 4 is a graph showing 50% purification temperatures of the catalysts of Example 2 and Comparative Example 2 after a rich lean durability test.
FIG. 5 shows the 50% purification temperatures of the catalysts of Example 2 and Comparative Example 2 after an air durability test.
FIG. 6 shows CeO of Examples 3 and 4. 2 -ZrO 2 4 is a graph showing a pore distribution of a solid solution powder.
Claims (11)
該沈殿物を洗浄する第２工程と、
洗浄後の該沈殿物を界面活性剤とともに水中で撹拌する第３工程と、
該第３工程後の沈殿物を焼成する第４工程と、を順次行うことを特徴とする金属酸化物の製造方法。A first step of obtaining a precipitate of an oxide precursor by adding an alkaline substance to an aqueous solution in which a compound containing a metal element to be an oxide is dissolved,
A second step of washing the precipitate;
A third step of stirring the precipitate after washing together with a surfactant in water;
And a fourth step of firing the precipitate after the third step.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104498A (en) * | 1976-01-05 | 1977-09-01 | Exxon Research Engineering Co | Process for preparing catalyst having preedetermined particle size distribution and pore volume |
| JPS56120508A (en) * | 1980-02-19 | 1981-09-21 | Chiyoda Chem Eng & Constr Co Ltd | Manufacture of porous inorganic oxide |
| JPS63302944A (en) * | 1987-03-11 | 1988-12-09 | フイリツプス ピトローリアム カンパニー | Production of alumina-silica composition |
| JPH01135542A (en) * | 1987-11-24 | 1989-05-29 | Toyota Motor Corp | Monolithic catalyst for purifying exhaust gas |
| JPH0350121A (en) * | 1989-05-10 | 1991-03-04 | Rhone Poulenc Chim | Porous zirconia and preparation thereof |
| JPH0455315A (en) * | 1990-06-21 | 1992-02-24 | Dainichiseika Color & Chem Mfg Co Ltd | Production of cerium oxide fine powder |
| JPH08333116A (en) * | 1995-04-13 | 1996-12-17 | Toyota Central Res & Dev Lab Inc | Powder |
| JPH09506587A (en) * | 1993-12-24 | 1997-06-30 | ローヌ−プーラン シミ | Precursors and mixed cerium or zirconium oxides, and methods of making and using these |
| JPH09221304A (en) * | 1995-12-07 | 1997-08-26 | Toyota Central Res & Dev Lab Inc | Oxide solid solution particle and its production |
| JPH10182155A (en) * | 1996-10-07 | 1998-07-07 | Toyota Central Res & Dev Lab Inc | Multiple oxide, multiple oxide support and catalyst containing the multiple oxide |
| JP2001524918A (en) * | 1997-04-21 | 2001-12-04 | ローディア レアー アースズ インコーポレイティド | Cerium oxide, zirconium oxide, Ce / Zr composite oxide and Ce / Zr solid solution with improved thermal stability and oxygen storage capacity |
-
2003
- 2003-02-10 JP JP2003032611A patent/JP4218364B2/en not_active Expired - Fee Related
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52104498A (en) * | 1976-01-05 | 1977-09-01 | Exxon Research Engineering Co | Process for preparing catalyst having preedetermined particle size distribution and pore volume |
| JPS56120508A (en) * | 1980-02-19 | 1981-09-21 | Chiyoda Chem Eng & Constr Co Ltd | Manufacture of porous inorganic oxide |
| JPS63302944A (en) * | 1987-03-11 | 1988-12-09 | フイリツプス ピトローリアム カンパニー | Production of alumina-silica composition |
| JPH01135542A (en) * | 1987-11-24 | 1989-05-29 | Toyota Motor Corp | Monolithic catalyst for purifying exhaust gas |
| JPH0350121A (en) * | 1989-05-10 | 1991-03-04 | Rhone Poulenc Chim | Porous zirconia and preparation thereof |
| JPH0455315A (en) * | 1990-06-21 | 1992-02-24 | Dainichiseika Color & Chem Mfg Co Ltd | Production of cerium oxide fine powder |
| JPH09506587A (en) * | 1993-12-24 | 1997-06-30 | ローヌ−プーラン シミ | Precursors and mixed cerium or zirconium oxides, and methods of making and using these |
| JPH08333116A (en) * | 1995-04-13 | 1996-12-17 | Toyota Central Res & Dev Lab Inc | Powder |
| JPH09221304A (en) * | 1995-12-07 | 1997-08-26 | Toyota Central Res & Dev Lab Inc | Oxide solid solution particle and its production |
| JPH10182155A (en) * | 1996-10-07 | 1998-07-07 | Toyota Central Res & Dev Lab Inc | Multiple oxide, multiple oxide support and catalyst containing the multiple oxide |
| JP2001524918A (en) * | 1997-04-21 | 2001-12-04 | ローディア レアー アースズ インコーポレイティド | Cerium oxide, zirconium oxide, Ce / Zr composite oxide and Ce / Zr solid solution with improved thermal stability and oxygen storage capacity |
Cited By (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010036187A (en) * | 2003-09-04 | 2010-02-18 | Rhodia Electronics & Catalysis | Composition based on cerium oxide and zirconium oxide having high reducibility and high specific surface, method for preparation thereof and use thereof as catalyst |
| JP4928273B2 (en) * | 2004-01-23 | 2012-05-09 | ベリー スモール パーティクル コンパニー リミテッド | Method for producing porous composite oxide |
| JP2007518659A (en) * | 2004-01-23 | 2007-07-12 | ベリー スモール パーティクル コンパニー ピーティーワイ リミテッド | Method for producing metal oxide |
| JP4660135B2 (en) * | 2004-07-26 | 2011-03-30 | 第一稀元素化学工業株式会社 | Zirconia-based porous body and method for producing the same |
| JP2006036576A (en) * | 2004-07-26 | 2006-02-09 | Daiichi Kigensokagaku Kogyo Co Ltd | Zirconia-based porous body and its production method |
| JP2006062942A (en) * | 2004-07-30 | 2006-03-09 | Dowa Mining Co Ltd | Perovskite-type composite oxide having pore distribution with high catalytic activity and catalyst |
| JP2006095513A (en) * | 2004-08-30 | 2006-04-13 | Toyota Central Res & Dev Lab Inc | Method for producing porous composite metal oxide |
| JP4696767B2 (en) * | 2004-08-30 | 2011-06-08 | 株式会社豊田中央研究所 | Method for producing composite metal oxide porous body |
| JP2008513195A (en) * | 2004-09-15 | 2008-05-01 | ロディア・シミ | Method for producing catalyst fine particle filter and filter obtained thereby |
| JP2006231321A (en) * | 2005-01-28 | 2006-09-07 | Toyota Central Res & Dev Lab Inc | Catalyst carrier and its production method |
| JP4665770B2 (en) * | 2005-01-28 | 2011-04-06 | 株式会社豊田中央研究所 | Catalyst carrier and method for producing the same |
| JP2006346528A (en) * | 2005-06-13 | 2006-12-28 | Toyota Central Res & Dev Lab Inc | Catalyst carrier for exhaust gas purification, catalyst for exhaust gas purification, and manufacturing method of catalyst carrier for exhaust gas purification |
| JP2007204363A (en) * | 2006-02-02 | 2007-08-16 | Samsung Sdi Co Ltd | Compound oxide carrier, its production method, low-temperature shift reaction catalyst and its production method, carbon monoxide removal method, fuel treatment apparatus, and fuel cell system |
| JP4662955B2 (en) * | 2006-02-02 | 2011-03-30 | 三星エスディアイ株式会社 | Method for producing composite oxide support, method for producing low temperature shift reaction catalyst, method for removing carbon monoxide, fuel processing apparatus and fuel cell system |
| JP2012125767A (en) * | 2007-01-25 | 2012-07-05 | Nissan Motor Co Ltd | Exhaust gas purifying catalyst and manufacturing method thereof |
| JP2008284534A (en) * | 2007-01-25 | 2008-11-27 | Nissan Motor Co Ltd | Exhaust gas purifying catalyst and its manufacturing method |
| JP2009249275A (en) * | 2008-04-09 | 2009-10-29 | Daiichi Kigensokagaku Kogyo Co Ltd | Cerium-zirconium-based composite oxide and its manufacturing process |
| US9757711B2 (en) | 2009-12-25 | 2017-09-12 | Solvay Special Chem Japan, Ltd. | Complex oxide, method for producing same, and exhaust gas purifying catalyst |
| WO2011078315A1 (en) * | 2009-12-25 | 2011-06-30 | 阿南化成株式会社 | Complex oxide, method for producing same, and exhaust gas purifying catalyst |
| CN102770373A (en) * | 2009-12-25 | 2012-11-07 | 阿南化成株式会社 | Complex oxide, method for producing same, and exhaust gas purifying catalyst |
| JPWO2011078315A1 (en) * | 2009-12-25 | 2013-05-09 | 阿南化成株式会社 | Composite oxide, method for producing the same and exhaust gas purification catalyst |
| JP5706339B2 (en) * | 2009-12-25 | 2015-04-22 | 阿南化成株式会社 | Composite oxide, method for producing the same and exhaust gas purification catalyst |
| JP2012187457A (en) * | 2011-03-09 | 2012-10-04 | Tayca Corp | Catalyst for selective reduction of nitrogen oxide, and method for production thereof |
| WO2020195973A1 (en) * | 2019-03-28 | 2020-10-01 | 第一稀元素化学工業株式会社 | Zirconia-based porous body |
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