JP4367693B2 - Hydrogen separator and method for producing the same - Google Patents

Hydrogen separator and method for producing the same Download PDF

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JP4367693B2
JP4367693B2 JP2003181483A JP2003181483A JP4367693B2 JP 4367693 B2 JP4367693 B2 JP 4367693B2 JP 2003181483 A JP2003181483 A JP 2003181483A JP 2003181483 A JP2003181483 A JP 2003181483A JP 4367693 B2 JP4367693 B2 JP 4367693B2
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hydrogen
porous substrate
metal layer
selective permeable
substrate
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JP2005013853A (en
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哲 山崎
修 酒井
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NGK Insulators Ltd
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

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Description

【０００１】
【発明の属する技術分野】
本発明は、水素分離体及びその製造方法に関し、更に詳しくは、熱サイクルを加えても水素分離層の剥離や欠陥が発生し難く、更に金属微粉末が表面に付着しても欠陥が発生し難く、それにより気密性が低下し難い水素分離体及びその製造方法に関する。
【０００２】
【従来の技術】
従来より、水蒸気改質ガス等の水素を含有するガスから水素のみを選択的に取り出すために、セラミック多孔質基体にパラジウム等からなる水素分離層を配設した水素分離体が使用されている。水素分離体は、高温において水素のみを分離するために使用されることがあるため、高温又は昇降温が繰り返される環境において高い気密性を有することが要求される。
【０００３】
パラジウム等の水素分離層をセラミック多孔質基体に配設して水素分離体を製造するときには、例えば、メッキ等の方法によりパラジウムをセラミック多孔質基体の表面に配設している（例えば、特許文献１〜３参照）。しかし、この場合、パラジウムとセラミック多孔質基体のそれぞれの熱膨張係数が異なり、更に、パラジウムとセラミック多孔質基体との濡れ性が良くないため、昇降温が繰り返され、熱サイクルが加えられると、パラジウムがセラミック多孔質基体の表面から剥離したり、パラジウムに欠陥が発生し、気密性が低下するという問題があった。また、パラジウムをセラミック多孔質基体に配設した後に銀等をパラジウムの表面に配設し、その後に加熱することにより、パラジウムと銀との合金をセラミック多孔質基体に配設して、水素分離層とする場合には、上記合金がセラミック多孔質基体から、より剥離し易くなるという問題があった。
【０００４】
また、水素分離体を使用しているときに、上記ガスに金属微粉末が含有されている場合には、この金属微粉末と、水素分離体の表面に配設されたパラジウム等の水素分離層とが反応することにより、欠陥が発生し、気密性が低下するという問題があった。
【０００５】
【特許文献１】
特開平３−１４６１２２号公報
【特許文献２】
特許第３２１３４３０号公報
【特許文献３】
特開昭６２−２７３０３０号公報
【０００６】
【発明が解決しようとする課題】
本発明は、このような従来技術の有する問題点に鑑みてなされたものであり、その目的とするところは、熱サイクルを加えても水素分離層の剥離や欠陥が発生し難く、更に金属微粉末が表面に付着しても欠陥が発生し難く、それにより気密性が低下し難い水素分離体及びその製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、本発明によって以下の水素分離体及びその製造方法が提供される。
【０００８】
［１］ その一の表面から他の表面まで連通する多数の細孔を有する多孔質基体と、前記多孔質基体に配設された、前記一の表面側から流入する水素を含む気体のうち水素だけを選択的に透過させて前記他の表面側から流出させることが可能な水素分離層とを備える水素分離体であって、
前記水素分離層が、前記多孔質基体の前記細孔のそれぞれの内部に、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで形成された水素選択透過性金属層によって構成されてなることを特徴とする水素分離体。
【００１０】
［２］ 前記水素分離層を構成する前記水素選択透過性金属層が、１〜５μｍの厚さで形成されてなる［１］に記載の水素分離体。
【００１１】
［３］ 前記水素分離層を構成する前記水素選択透過性金属層が、パラジウム又はパラジウムを含有する合金からなる［１］又は［２］に記載の水素分離体。
【００１２】
［４］ 前記多孔質基体がセラミックを主成分としてなる［１］〜［３］のいずれかに記載の水素分離体。
【００１３】
［５］ その一の表面から他の表面まで連通する多数の細孔を有する多孔質基体と、前記多孔質基体に配設された、前記一の表面側から流入する水素を含む気体のうち水素だけを選択的に透過させて前記他の表面側から流出させることが可能な水素分離層とを備える水素分離体を製造する方法であって、前記多孔質基体の表面及び前記細孔の内壁に、活性化金属を付着させて、活性化金属付着基体を作製し、前記活性化金属付着基体に付着した前記活性化金属のうち、前記多孔質基体の表面、及び前記細孔の内壁の、前記多孔質基体の一の表面から所定の深さの部位までに付着した前記活性化金属を除去して、前記多孔質基体の一の表面から所定の深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで、前記細孔の内壁に前記活性化金属が付着した活性化処理基体を作製し、前記活性化処理基体に前記活性化金属を核として化学メッキ処理して、前記活性化金属が付着した位置に前記水素選択透過性金属層を形成することにより、前記多孔質基体の前記細孔のそれぞれの内部に、前記多孔質基体の一の表面から所定の深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで形成された水素選択透過性金属層によって構成された前記水素分離層を配設して、前記水素分離体を得ることを特徴とする水素分離体の製造方法。
【００１４】
［６］ 前記水素分離層を構成する前記水素選択透過性金属層が、パラジウム又はパラジウムを含有する合金からなる［５］に記載の水素分離体の製造方法。
【００１５】
［７］ 前記活性化金属付着基体から前記活性化金属を除去するときに、前記活性化金属付着基体を酸性溶液に浸漬して、前記活性化金属を酸性溶液に溶解させて除去する［５］又は［６］に記載の水素分離体の製造方法。
【００１６】
［８］ 前記酸性溶液が、塩酸と硝酸とを混合した混酸である［７］に記載の水素分離体の製造方法。
【００１７】
［９］ 前記多孔質基体が、セラミックを主成分としてなる［５］〜［８］のいずれかに記載の水素分離体の製造方法。
【００１８】
［１０］ 前記水素分離層を構成する前記水素選択透過性金属層を、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から形成する［５］〜［９］のいずれかに記載の水素分離体の製造方法。
【００１９】
［１１］ 前記水素分離層を構成する前記水素選択透過性金属層を、１〜５μｍの厚さで形成する［５］〜［１０］のいずれかに記載の水素分離体の製造方法。
【００２０】
［１２］ 前記水素選択透過性金属層を形成した後に、前記水素選択透過性金属層の、前記多孔質基体の一の表面側の表面に、電気メッキにより合金形成用金属層を形成し、前記水素選択透過性金属層及び前記合金形成用金属層を加熱し、水素選択透過性金属と合金形成用金属との合金から構成される合金化された水素選択透過性金属層を形成することにより、前記合金化された水素選択透過性金属層から構成される前記水素分離層を配設する［５］〜［１１］のいずれかに記載の水素分離体の製造方法。
【００２１】
［１３］ 前記水素分離層を構成する前記合金化された水素選択透過性金属層を、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から形成する［１２］に記載の水素分離体の製造方法
【００２２】
［１４］ 前記水素分離層を構成する前記合金化された水素選択透過性金属層を、１〜５μｍの厚さで形成する［１２］又は［１３］に記載の水素分離体の製造方法。
【００２３】
このように、本発明の水素分離体によれば、多孔質基体に配設される水素分離層が、多孔質基体の細孔のそれぞれの内部に、多孔質基体の一の表面から所定の深さの部位から形成された水素選択透過性金属層によって構成されてなることにより、水素分離層が多孔質基体の細孔内部に保持され、自由に膨脹・収縮することが抑制されるため、水素分離体に熱サイクルを加えても、水素分離層が多孔質基体から剥離したり、水素分離層に欠陥が生じたりすることを抑制することができる。また、水素分離層が、多孔質基体の一の表面から所定の深さの部位から形成されることにより、水素分離層が水素分離体の表面に存在しなくなるため、金属微粉末が水素分離体の表面に付着しても、水素分離層と接触することがなく、水素分離層に欠陥が生じることを抑制することができる。
【００２４】
また、本発明の水素分離体の製造方法によれば、多孔質基体に活性化金属を付着させて活性化処理基体を作製するときに、多孔質基体の一の表面から所定の深さの部位から、多孔質基体の他の表面側に向かって所定の厚さで、細孔の内壁に活性化金属を付着させ、その活性化金属を核として水素選択透過性金属層を形成したため、水素分離層が、多孔質基体の細孔のそれぞれの内部に、多孔質基体の一の表面から所定の深さの部位から多孔質基体の他の表面側に向かって所定の厚さで形成された、水素選択透過性金属層によって構成されてなる水素分離体を作製することができる。
【００２５】
【発明の実施の形態】
次に本発明の実施の形態を図面を参照しながら詳細に説明するが、本発明は以下の実施の形態に限定されるものではなく、本発明の趣旨を逸脱しない範囲で、当業者の通常の知識に基づいて、適宜設計の変更、改良等が加えられることが理解されるべきである。
【００２６】
図１は、本発明の水素分離体の一の実施の形態を模式的に示す、水素分離層に垂直な平面で切断して要部を拡大した断面図である。
【００２７】
図１に示すように、本実施の形態の水素分離体１は、その一の表面５から他の表面（図示せず）まで連通する多数の細孔４を有する多孔質基体２と、多孔質基体２に配設された、一の表面５側から流入する水素を含む気体のうち水素だけを選択的に透過させて他の表面（図示せず）側から流出させることが可能な水素分離層３とを備え、水素分離層３が、多孔質基体２の細孔４のそれぞれの内部に、多孔質基体２の一の表面５から所定の深さの部位７から、多孔質基体２の他の表面（図示せず）側に向かって所定の厚さＷで形成された水素選択透過性金属層６によって構成されてなることを特徴とする。多孔質基体２の細孔４は、水素選択透過性金属８により上記所定の厚さＷの範囲で閉塞され、上記一の表面５側と他の表面（図示せず）側との気密性が保たれている。
【００２８】
このように、水素選択透過性金属層６によって構成される水素分離層３が、多孔質基体２の一の表面５には存在せず、細孔４の内部に入り込んで存在しているため、水素分離体１に熱サイクルが加わり、多孔質基体２及び水素分離層３が膨脹、収縮を繰り返しても、水素分離層３が細孔４に保持されながら膨脹、収縮するため、多孔質基体２との剥離が生じ難く、気密性を保つことができる。また、水素分離層３が多孔質基体２の一の表面５から所定の深さの部位７から多孔質基体２の他の表面（図示せず）側に向かって形成されているため、多孔質基体２の一の表面５から、所定の深さの部位７までの細孔４には何も充填されていない状態となり、金属微粉末が水素分離体１の表面に付着しても水素分離層３に欠陥が生じることを抑制することができる。
【００２９】
水素分離層３を構成する水素選択透過性金属層６は、多孔質基体２の一の表面５から０．１〜５μｍの深さの部位から形成されることが好ましい。さらに０．３〜２μｍの深さの部位から形成されることがより好ましい。つまり、多孔質基体２の一の表面５から所定の深さの部位７における、所定の深さが、０．１〜５μｍである。この所定の深さが０．１μｍより小さいと、金属微粉末が水素分離体１の表面に付着したときに水素分離層３にも付着し、水素分離層３に欠陥が生じることがある。また、この所定の深さが５μｍより大きいと、一の表面５から、所定の深さの部位７までの細孔４に水素濃度が低下したガス（水素を含む気体）が滞留し、水素の分離効率が低下することがある。
【００３０】
水素分離層３を構成する水素選択透過性金属層６の所定の厚さＷは、１〜５μｍが好ましい。１μｍより薄いと、水素分離層３に欠陥が生じ易くなることがあり、５μｍより厚いと、水素分離層３による水素分離の分離効率が低下することがある。
【００３１】
水素選択透過性金属層６を構成する水素選択透過性金属層は、パラジウム又はパラジウムを含有する合金からなることが好ましい。
【００３２】
多孔質基体２が、セラミックを主成分とする多孔質体であることが好ましい。セラミックを主成分とすることにより、耐熱性、耐食性等に優れ、機械的強度の強い水素分離体１とすることができる。セラミックとしては特に限定されるものではなく、水素分離体として一般的に使用されるセラミックのいずれでも採用することができる。例えば、アルミナ、シリカ、シリカ−アルミナ、ムライト、コージェライト、ジルコニア等が挙げられる。セラミック以外の成分としては、不可避的に含有される成分や、通常添加されるような成分を少量含有してもよい。また、セラミック以外にも、カーボンや多孔質ガラスを用いることもできる。尚、多孔質基体２の厚さは、特に制限されない。使用環境において充分な機械強度を保持できればよい。
【００３３】
この多孔質基体２は、３次元状に連続した多数の微細な細孔４を有するものであるが、この細孔４の孔径は、０．００３〜２μｍであることが好ましく、０．１〜１μｍ以下であることが、より好ましい。孔径が０．００３μｍ未満では、ガスが通過するときの抵抗が大きくなることがある。一方、孔径が２μｍを超えると、本実施の形態の水素分離体１を製造するときに、化学メッキにより水素選択透過性金属層６を配設する場合には、水素選択透過性金属８により細孔４を閉塞し難くなるので、好ましくない。
【００３４】
また、多孔質基体２の細孔４は、孔径が揃っていることが好ましい。これにより、上記化学メッキにより水素選択透過性金属層６を配設する場合に、メッキ溶液を細孔４に漏れなく均一に侵入させ易く、水素選択透過性金属８が充填されない細孔４が生じてしまう問題を回避できる。
【００３５】
次に、本発明の水素分離体の製造方法の一の実施の形態について、図面を参照しながら詳細に説明する。
【００３６】
図２は、本実施の形態の水素分離体の製造方法において、多孔質基体に活性化金属を付着させた状態を模式的に示す、多孔質基体の一の表面付近を拡大した断面図である。図３は、本実施の形態の水素分離体の製造方法において、多孔質基体に付着させた活性化金属のうち、多孔質基体の一の表面から所定の深さの部位までに付着した活性化金属を除去した状態を模式的に示す、多孔質基体の一の表面付近を拡大した断面図である。図４は、本実施の形態の水素分離体の製造方法で製造した水素分離体を示す、多孔質基体の一の表面付近を拡大した断面図である。
【００３７】
本実施の形態の水素分離体の製造方法は、まず、図２に示すように、多孔質基体２２の一の表面２５及び細孔２４の内壁に、活性化金属２９を付着させて、活性化金属付着基体２０を作製する。
【００３８】
次に、得られた活性化金属付着基体２０に付着した活性化金属２９のうち、多孔質基体２２の一の表面２５及び細孔２４の内壁の、多孔質基体２２の一の表面２５から所定の深さの部位２７までに付着した活性化金属２９を除去して、図３に示すような、多孔質基体２２の一の表面２５から所定の深さの部位２７から、多孔質基体２２の他の表面（図示せず）側に向かって所定の厚さＷで、細孔２４の内壁に活性化金属２９が付着した活性化処理基体３０を作製する。
【００３９】
そして、得られた活性化処理基体３０に、活性化金属２９を核として化学メッキ処理して、図４に示すように、活性化金属２９（図３参照）が付着した位置に水素選択透過性金属層２６を形成することにより、多孔質基体２２の細孔２４のそれぞれの内部に、多孔質基体２２の一の表面２５から所定の深さの部位２７から、多孔質基体２２の他の表面（図示せず）側に向かって所定の厚さＷで形成された水素選択透過性金属層２６によって構成された水素分離層２３を配設して、水素分離体４０を得る。水素分離層２３を構成する水素選択透過性金属層２６は、細孔２４が水素選択透過性金属２８で充填され閉塞されており、水素以外のガスが細孔２４を通過しないように形成されている。
【００４０】
このように、活性化金属付着基体に付着した活性化金属のうち、多孔質基体の一の表面から所定の深さの部位までに付着した活性化金属を除去して、その後に、化学メッキにより水素選択透過性金属層を形成したため、水素分離層を水素分離体の内部の所望の位置に配設することができる。
【００４１】
本実施の形態の水素分離体の製造方法においては、図２に示す活性化金属２９を多孔質基体２２に付着させるときには、多孔質基体２２を活性化金属２９を含有する溶液に浸漬させ、多孔質基体２２の一の表面２５側に活性化金属２９を含有する溶液を付着させ、水洗する。このとき、多孔質基体２２の他の表面（図示せず）側を減圧し、活性化金属２９を含有する溶液を多孔質基体２２の細孔２４の内部の所望の部位まで浸透させてもよい。また、多孔質基体２２の他の表面（図示せず）側にも活性化金属２９を付着させてもよい。
【００４２】
活性化金属２９を付着させる方法としては、パラジウム２価イオンを含有する化合物を好適に用いることができる。活性化金属２９を多孔質基体２２に付着させる方法としては、水素選択透過性金属としてパラジウムを配設する場合には、多孔質基体２２を塩化パラジウムの塩酸水溶液と、塩化錫の塩酸水溶液に交互に浸漬させることが好ましい。
【００４３】
本実施の形態の水素分離体の製造方法において、図２に示す、多孔質基体２２の一の表面２５から所定の深さの部位２７までに付着した活性化金属２９を、活性化金属付着基体２０から除去する方法としては、活性化金属付着基体２０を酸性溶液に浸漬して、活性化金属２９を酸性溶液に溶解させて除去することが好ましい。酸性溶液の種類としては、塩酸と硝酸との混酸を使用することが好ましい。混酸中の塩酸（塩化水素）と硝酸との合計の濃度（酸濃度）は４０〜７５質量％が好ましい。また、塩化水素と硝酸との質量比の値（塩化水素／硝酸）は、１／６〜２／７が好ましい。
【００４４】
活性化金属付着基体２０を酸性溶液に浸漬する時間は特に限定されるものではなく、酸性溶液の組成、濃度によって適宜決定することができるが、１０〜２５秒が好ましい。
【００４５】
図３に示すような、多孔質基体２２の細孔２４の内壁に所定の厚さＷで、活性化金属２９が付着した活性化処理基体３０に、化学メッキをして、図４に示すような、活性化金属２９（図３参照）が付着した位置に水素選択透過性金属層２６を形成するために、図３に示す活性化処理基体３０を水素選択透過性金属と還元剤とを含有するメッキ溶液に浸漬させる。このとき、活性化処理基体３０は、多孔質基体２２の一の表面２５側がメッキ溶液に接触するように浸漬し、多孔質基体２２の他の表面（図示せず）側から減圧することにより、メッキ溶液が多孔質基体２２の細孔２４内の、活性化金属２９が配設されている位置より深い位置まで浸入するようにすることが好ましい。そして、メッキ溶液が細孔２４の内部まで浸入することにより、活性化金属２９を核として水素選択透過性金属が析出し、活性化金属２９が付着した位置に水素選択透過性金属層２６（図４参照）が形成される。これにより、図４に示すように、多孔質基体２２の細孔２４のそれぞれの内部に、多孔質基体２２の一の表面２５から所定の深さの部位２７から、多孔質基体２２の他の表面（図示せず）側に向かって所定の厚さＷで形成された水素選択透過性金属層２６によって構成された水素分離層２３を配設して、水素分離体４０を得ることができる。メッキ溶液の浸入する深さは、浸漬時間、メッキ溶液の温度、多孔質基体２２にかかる減圧等により生じる両面（一の表面２５と他の表面）の圧力差等を調節することにより、制御することができる。
【００４６】
図４に示す、多孔質基体２２の一の表面２５から所定の深さの部位２７と、多孔質基体２２の一の表面２５との距離は金属微粉末等が付着しなければ特に限定されるものではないが、０．１〜５μｍが好ましい。つまり、水素分離層２３を構成する水素選択透過性金属層２６を、多孔質基体２２の一の表面２５から０．１〜５μｍの深さの部位（所定の深さの部位２７）から形成することが好ましい。０．１μｍより浅いと金属微粉末等が水素選択透過性金属に付着することがあり、５μｍより深いと一の表面２５から、所定の深さの部位２７までの細孔２４に水素濃度が低下したガス（水素を含む気体）が滞留し、水素の分離効率が低下することがある。図２及び図３に示す、多孔質基体２２の一の表面２５から所定の深さ２７も同じ位置に形成される。
【００４７】
図４に示す、水素分離層２３を構成する水素選択透過性金属層２６の所定の厚さＷは、水素選択透過性金属層２６に欠陥が生じ難く、且つ水素透過性が良好であれば特に限定されるものではないが、１〜５μｍが好ましい。１μｍより薄いと、水素分離層２３に欠陥が生じ易くなることがあり、５μｍより厚いと、水素分離層２３による水素分離の分離効率が低下することがある。
【００４８】
図４に示す、多孔質基体２２が、セラミックを主成分とする多孔質体であることが好ましい。セラミックを主成分とすることにより、耐熱性、耐食性等に優れ、機械的強度の強い水素分離体４０とすることができる。セラミックとしては特に限定されるものではなく、水素分離体として一般的に使用されるセラミックのいずれでも採用することができる。例えば、アルミナ、シリカ、シリカ−アルミナ、ムライト、コージェライト、ジルコニア等が挙げられる。また、セラミック以外にも、カーボンや多孔質ガラスを用いることもできる。尚、多孔質基体２２の厚さは、特に制限されない。使用環境において充分な機械強度を保持できればよい。
【００４９】
この多孔質基体２２は、３次元状に連続した多数の微細な細孔２４を有するものであるが、この細孔２４の孔径は、０．００３〜２μｍであることが好ましく、０．１〜１μｍ以下であることが、より好ましい。孔径が０．００３μｍ未満では、ガスが通過するときの抵抗が大きくなることがある。一方、孔径が２μｍを超えると、本実施の形態の水素分離体の製造方法において、化学メッキ処理を行う場合に、水素選択透過性金属２８により細孔２４を閉塞し難くなるので、好ましくない。
【００５０】
また、多孔質基体２２の細孔２４は、孔径が揃っていることが好ましい。これにより、化学メッキにより水素選択透過性金属層２６を配設する場合に、メッキ溶液を細孔２４に漏れなく均一に侵入させ易く、水素選択透過性金属２８が充填されない細孔２４が生じてしまう問題を回避できる。
【００５１】
本実施の形態の水素分離体の製造方法においては、水素分離層を構成する水素選択透過性金属層は、パラジウム又はパラジウムを含有する合金からなることが好ましい。水素選択透過性金属層をパラジウムを含有する合金からなるようにするためには、上述した製造方法によりパラジウムを化学メッキすることにより水素選択透過性金属層を形成した後、その水素選択透過性金属層の表面に銀を更にメッキして合金形成用金属層を形成し、次いで、加熱することにより、パラジウムと銀とを相互拡散させ、水素選択透過性金属と合金形成用金属とを合金化し、合金化された水素選択透過性金属層を形成することが好ましい。水素選択透過性金属層の表面に銀をメッキするときは、水素選択透過性金属層を構成するパラジウムを電極として、電気メッキすることが好ましい。このとき、パラジウムと銀との質量比（パラジウム：銀）が９０：１０〜７０：３０であることが好ましい。パラジウムを合金化する主目的は、パラジウムの水素脆化防止と高温時の分離効率向上である。また、パラジウム以外の金属として銀を使用することにより、パラジウムの水素による脆化がより効果的に防止される。
【００５２】
水素分離層を構成する合金化された水素選択透過性金属層は、多孔質基体の一の表面から０．１〜５μｍ深さの部位から形成することが好ましい。０．１μｍより浅いと金属微粉末等が水素選択透過性金属に付着することがあり、５μｍより深いと一の表面５から、所定の深さの部位７までの細孔４に水素濃度が低下したガス（水素を含む気体）が滞留し、水素の分離効率が低下することがある。
【００５３】
水素分離層を構成する合金化された水素選択透過性金属層は、１〜５μｍの厚さで形成することが好ましい。１μｍより薄いと、水素分離層に欠陥が生じ易くなることがあり、５μｍより厚いと、水素分離層による水素の分離の分離効率が低下することがある。
【００５４】
【実施例】
以下、本発明を実施例により具体的に説明するが、本発明はこれら実施例に限定されるものではない。
【００５５】
（実施例１）
多孔質基体として、円筒状の非対称型無機多孔質材料（α−アルミナ製、ＮＧＫアドレック（株）製）を用いた。この多孔質基体は外径１０ｍｍ、内径７ｍｍ、長さ１１０ｍｍで、その細孔径は０．１μｍである。この多孔質管（多孔質基体）を水で洗浄し、次いで乾燥した。次いで、脱脂処理として奥野製薬（株）製ＯＰＣ３７０を１０体積％含む溶液を７０℃に保持し、５分間浸漬した後、水洗した。
【００５６】
次いで、多孔質基体を活性化処理した（一度目の活性化処理）。上記円筒状の多孔質基体を、奥野製薬（株）製ＯＰＣプリディップを１体積％含む溶液に２分間浸漬した。次に、奥野製薬（株）製インデューサーＡ及びインデューサーＣを各々５体積％含む溶液を５０℃に保持し、５分間浸漬した後、水洗した。次に、奥野製薬（株）製クリスターＭＵを１５体積％含む溶液に５分間浸漬した。次に、奥野製薬（株）製クリスターＭＵを３体積％含む溶液に１分間浸漬した後、水洗して、活性化金属としてパラジウム核が付着した活性化金属付着基体を得た。
【００５７】
次いで、活性化金属付着基体の表面及び細孔内部の一部のパラジウム核を酸性溶液により溶解洗浄した（酸処理）。上記活性化金属付着基体を、塩酸（３６質量％）と硝酸（６９質量％）及び水との容積比が１：４：５の酸溶液に１５秒間浸漬し、その後に水洗した。
【００５８】
次いで、再度、活性化処理（二度目の活性化処理）を行った。上記酸洗浄した活性化金属付着基体を、奥野製薬（株）製クリスターＭＵを１５体積％含む溶液に５分間浸漬した。次に、奥野製薬（株）製クリスターＭＵを３体積％含む溶液に１分間浸漬し、水洗して、活性化処理基体を得た。
【００５９】
次いで、上記活性化処理基体を化学メッキ処理することによりパラジウムを水素選択透過性金属とした水素分離層を形成した。イオンを除去した水１Ｌ（リットル）中に［Ｐｄ（ＮＨ3）4］Ｃｌ2・Ｈ2Ｏ（５．４ｇ）、２Ｎａ・ＥＤＴＡ（６７．２ｇ）、アンモニア濃度２８質量％のアンモニア水（６５１．３ｍＬ）及びＨ2ＮＮＨ2・Ｈ2Ｏ（０．６４ｍＬ）を加えた水溶液を準備した。そして上記水溶液を５０℃に温度制御し、上記活性化処理基体の外表面をその水溶液に浸漬させ、活性化処理基体の円筒形状の内側を真空ポンプで引いて減圧した。浸漬時間は１５分とし、これにより活性化処理基体の内部でパラジウム核が付着した部分にのみパラジウムからなる水素分離層が形成された多孔質基体を得た。
【００６０】
ここで、酸性溶液による洗浄を行うときに、活性化処理した多孔質基体の円筒形状の両端部の外周面に、細い（約１０ｍｍ）シールテープを巻き、酸性溶液から隔離した。これにより、活性化金属付着基体を化学メッキ処理するときに、この両端部の外周面に、多孔質基体の細孔内部に析出したパラジウムと連続する緻密な細いパラジウム膜を容易に形成することができる。そして、これを次工程の電気メッキの電極及び、水素分離体の気密シール部分とすることができる。
【００６１】
次いで、上述の多孔質基体の両端部の外周面に形成された細いパラジウム膜を電極として、銀を電気メッキし、パラジウムと銀の重量比が８０：２０となるように調節した。そして、最後に、９００℃で１時間保持して、熱処理を行い、パラジウムと銀とを相互拡散させ、パラジウムと銀とを合金化し、水素分離体（実施例１）を得た。得られた水素分離体の微構造を図５に示す。図５は、本実施例の水素分離体５０において、水素分離層５３に略垂直な平面で切断した断面を示す顕微鏡写真である。図５より、得られた水素分離体５０は、水素分離層５３が、多孔質基体５２の細孔のそれぞれの内部に、多孔質基体５２の一の表面５５から所定の深さの部位５７から、多孔質基体５２の他の表面（図示せず）側に向かって所定の厚さで形成された水素選択透過性金属層５６によって構成されてなることがわかる。蛍光Ｘ線強度の測定により、水素選択透過性金属層５６の厚さは４．２μｍであった。また、得られた顕微鏡写真（図５参照）による水素選択透過性金属層５６の厚さも同程度の値であった。
【００６２】
（実施例２）
実施例１において、活性化処理基体を化学メッキ処理するときの浸漬時間を１０分として、水素分離層が形成された多孔質基体を得たこと以外は、実施例１と同様にして水素分離体（実施例２）を得た。得られた水素選択透過性金属層は多孔質基体の表面より深さ０．５μｍの位置から多孔質基体の内部へ形成されており、水素蛍光Ｘ線強度の測定により、水素選択透過性金属層の厚さは１．９μｍであった。また、顕微鏡写真（図示せず）による水素選択透過性金属層の厚さも同程度の値であった。
【００６３】
こうして得られた水素分離体（実施例１，２）について気密試験を行った。ヘリウムガスを円筒状の水素分離体の外部に導入し、９００ｋＰａの圧力で保持し、円筒状の水素分離体の内部に漏洩するガス量（Ｈｅ漏洩量）を測定した。結果を表１におけるサイクル数０の欄に示す。また、水素分離体（実施例１，２）について以下の方法で熱サイクル試験を行った。
【００６４】
（熱サイクル試験）
水素雰囲気中にある水素分離体を室温から５００℃まで加熱し、次いで室温まで冷却した。この加熱・冷却サイクルを１サイクルとして、１００サイクル行った。１０サイクル毎に上記Ｈｅ漏洩量を測定し、１００サイクルまでの熱サイクル試験後のＨｅ漏洩量を測定した結果を表１に示す。
【００６５】
（比較例１）
実施例１において、一度目の活性化処理の後、酸処理及び二度目の活性化処理を行わず、ヒドラジン処理を行って、活性化処理基体を得た。得られた活性化処理基体を実施例１と同様にパラジウム化学メッキを行い、水素分離体（比較例１）を得た。得られた水素選択透過性金属層は多孔質基体の表面に形成され、蛍光Ｘ線強度の測定により、水素選択透過性金属層の厚さは４．３μｍであった。また、顕微鏡写真（図示せず）による水素選択透過性金属層の厚さも同程度の値であった。こうして得られた水素分離体について、上記気密試験及び、熱サイクル試験を行った。結果を表１に示す。
【００６６】
（比較例２）
比較例１において、活性化処理基体を化学メッキ処理するときの浸漬時間を１０分として、水素分離層が形成された多孔質基体を得たこと以外は、比較例１と同様にして水素分離体（比較例２）を得た。得られた水素選択透過性金属層は多孔質基体の表面に形成され、蛍光Ｘ線強度の測定により、水素選択透過性金属層の厚さは２．０μｍであった。また、顕微鏡写真（図示せず）による水素選択透過性金属層の厚さも同程度の値であった。
【００６７】
【表１】

Figure 0004367693
【００６８】
図５より、多孔質基体の活性化処理後の酸性溶液による洗浄により、多孔質基体の細孔内部にのみ水素選択透過性金属層を形成させた水素分離体が製造できることがわかる。また、表１より、多孔質基体の細孔の内部にのみ水素選択透過性金属層を形成させた本発明の水素分離体は、従来の水素分離体に比して、昇降温サイクルにおいて長期にわたり高い気密性を維持できることがわかる。本発明の水素分離体は水素選択透過性金属層がセラミック多孔質基体の細孔の内部にのみ形成されている構造を有するため、水素選択透過性金属層の膨張を抑制し、昇降温サイクルによる欠陥の発生を抑制できる。また、水素分離体の外表面がセラミックであるため、金属微粉末が水素選択透過性金属層の表面に付着、反応することを防止できる。この結果、水素分離体の耐久性が大幅に向上できる。
【００６９】
【発明の効果】
上述したように、本発明の水素分離体によれば、多孔質基体に配設される水素分離層が、多孔質基体の細孔のそれぞれの内部に、多孔質基体の一の表面から所定の深さの部位から形成された水素選択透過性金属層によって構成されてなることにより、水素分離層が多孔質基体の細孔内部に保持され、自由に膨脹・収縮することが抑制されるため、水素分離体に熱サイクルを加えても、水素分離層が多孔質基体から剥離したり、水素分離層に欠陥が生じたりすることを抑制することができる。また、水素分離層が、多孔質基体の一の表面から所定の深さの部位から形成されることにより、水素分離層が水素分離体の表面にほとんど存在しなくなるため、金属微粉末が水素分離体の表面に付着しても、水素分離層とほとんど接触することがなく、水素分離層に欠陥が生じることを抑制することができる。
【００７０】
また、本発明の水素分離体の製造方法によれば、多孔質基体に活性化金属を付着させて活性化処理基体を作製するときに、多孔質基体の一の表面から所定の深さの部位から、多孔質基体の他の表面側に向かって所定の厚さで、細孔の内壁に活性化金属を付着させ、その活性化金属を核として水素選択透過性金属層を形成したため、水素分離層が、多孔質基体の細孔のそれぞれの内部に、多孔質基体の一の表面から所定の深さの部位から多孔質基体の他の表面側に向かって所定の厚さで形成された、水素選択透過性金属層によって構成されてなる水素分離体を作製することができる。
【図面の簡単な説明】
【図１】 本発明の水素分離体その製造方法の一の実施の形態を模式的に示す、水素分離層に垂直な平面で切断して要部を拡大した断面図である。
【図２】 本発明の水素分離体の製造方法の一の実施の形態において、多孔質基体に活性化金属を付着させた状態を模式的に示す、多孔質基体の一の表面付近を拡大した断面図である。
【図３】 本発明の水素分離体の製造方法の一の実施の形態において、多孔質基体に付着させた活性化金属のうち、多孔質基体の一の表面から所定の深さの部位までに付着した活性化金属を除去した状態を模式的に示す、多孔質基体の一の表面付近を拡大した断面図である。
【図４】 本発明の水素分離体の製造方法の一の実施の形態において製造した水素分離体を示す、多孔質基体の一の表面付近を拡大した断面図である。
【図５】 本発明の水素分離体の実施例において、水素分離層に略垂直な平面で切断した断面を示す顕微鏡写真である。
【符号の説明】
１，４０，５０…水素分離体、２，２２，５２…多孔質基体、３，２３，５３…水素分離層、４，２４…細孔、５，２５，５５…一の表面、６，２６，５６…水素選択透過性金属層、７，２７，５７…所定の深さの部位、８，２８…水素選択透過性金属、２０…活性化金属付着基体、２９…活性化金属、３０…活性化処理基体、Ｗ…所定の厚さ。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydrogen separator and a method for producing the same, and more particularly, even if a thermal cycle is applied, peeling or defects of the hydrogen separation layer hardly occur, and even if metal fine powder adheres to the surface, defects occur. The present invention relates to a hydrogen separator and a method for producing the same, which are difficult to reduce hermeticity.
[0002]
[Prior art]
Conventionally, in order to selectively extract only hydrogen from a gas containing hydrogen such as steam reformed gas, a hydrogen separator in which a hydrogen separation layer made of palladium or the like is disposed on a ceramic porous substrate has been used. Since the hydrogen separator may be used to separate only hydrogen at a high temperature, the hydrogen separator is required to have high airtightness in an environment where high temperature or temperature rise and fall are repeated.
[0003]
When a hydrogen separator such as palladium is disposed on a ceramic porous substrate to produce a hydrogen separator, for example, palladium is disposed on the surface of the ceramic porous substrate by a method such as plating (for example, Patent Documents). 1-3). However, in this case, the thermal expansion coefficients of palladium and the ceramic porous substrate are different, and furthermore, the wettability between the palladium and the ceramic porous substrate is not good, so when the temperature rise and fall is repeated and a thermal cycle is applied, There has been a problem that palladium peels off from the surface of the ceramic porous substrate, or defects occur in the palladium, resulting in a decrease in airtightness. In addition, after palladium is disposed on the ceramic porous substrate, silver or the like is disposed on the surface of the palladium, and then an alloy of palladium and silver is disposed on the ceramic porous substrate by heating to separate hydrogen. In the case of forming a layer, there is a problem that the alloy is more easily separated from the ceramic porous substrate.
[0004]
In addition, when a hydrogen separator is used, if the gas contains a metal fine powder, the metal fine powder and a hydrogen separation layer such as palladium disposed on the surface of the hydrogen separator. As a result of the reaction, defects occur and the airtightness decreases.
[0005]
[Patent Document 1]
JP-A-3-146122
[Patent Document 2]
Japanese Patent No. 3213430
[Patent Document 3]
JP-A-62-273030
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of such problems of the prior art. The object of the present invention is to prevent the separation or defects of the hydrogen separation layer from occurring even when a thermal cycle is applied. It is an object of the present invention to provide a hydrogen separator and a method for producing the same, in which defects do not easily occur even if the powder adheres to the surface, and the hermeticity is not easily lowered.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides the following hydrogen separator and method for producing the same.
[0008]
[1] Hydrogen among a gas including a porous substrate having a large number of pores communicating from one surface to another surface, and hydrogen flowing from the one surface side disposed on the porous substrate. A hydrogen separator comprising a hydrogen separation layer that can selectively permeate and flow out from the other surface side,
The hydrogen separation layer is formed from one surface of the porous substrate inside each of the pores of the porous substrate. 0.1-5 μm A hydrogen separator comprising a hydrogen selective permeable metal layer formed with a predetermined thickness from a portion having a depth toward the other surface of the porous substrate.
[0010]
[ 2 The hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 μm [1] ] A hydrogen separator according to 1.
[0011]
[ 3 The hydrogen selective permeable metal layer constituting the hydrogen separation layer is made of palladium or an alloy containing palladium [1]. Or [2] A hydrogen separator according to 1.
[0012]
[ 4 [1] to [1], wherein the porous substrate is mainly composed of ceramic. 3 ] The hydrogen separator in any one of.
[0013]
[ 5 ] A porous substrate having a large number of pores communicating from one surface to another surface, and only hydrogen out of a gas including hydrogen flowing from the one surface side and disposed on the porous substrate. A hydrogen separator comprising a hydrogen separation layer that can be selectively permeated and allowed to flow out from the other surface side, and is active on the surface of the porous substrate and the inner walls of the pores. An activated metal-attached substrate is prepared by attaching an activated metal, and among the activated metals attached to the activated metal-attached substrate, the porous surface of the porous substrate and the inner wall of the pore The activated metal adhering from one surface of the substrate to a portion having a predetermined depth is removed, and the other portion of the porous substrate is removed from a portion having a predetermined depth from one surface of the porous substrate. At a predetermined thickness toward the surface side, the inner wall of the pores An activation treatment substrate with an activated metal attached is prepared, and the activation treatment substrate is subjected to a chemical plating treatment using the activated metal as a nucleus, and the hydrogen selective permeable metal layer is formed at a position where the activation metal is attached. By forming, in each of the pores of the porous substrate, a predetermined depth from one surface of the porous substrate toward the other surface side of the porous substrate is predetermined. A method for producing a hydrogen separator, characterized in that the hydrogen separator is formed by disposing the hydrogen separator composed of a hydrogen selective permeable metal layer formed in a thickness of
[0014]
[ 6 The hydrogen selective permeable metal layer constituting the hydrogen separation layer is made of palladium or an alloy containing palladium [ 5 ] The manufacturing method of the hydrogen separator of description.
[0015]
[ 7 When removing the activated metal from the activated metal adhesion substrate, the activated metal adhesion substrate is immersed in an acidic solution, and the activated metal is dissolved in the acidic solution and removed. 5 ] Or [ 6 ] The manufacturing method of the hydrogen separator of description.
[0016]
[ 8 The acidic solution is a mixed acid obtained by mixing hydrochloric acid and nitric acid. 7 ] The manufacturing method of the hydrogen separator of description.
[0017]
[ 9 The porous substrate is mainly composed of ceramic [ 5 ] ~ [ 8 ] The manufacturing method of the hydrogen separator in any one of.
[0018]
[ 10 The hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed from a portion having a depth of 0.1 to 5 μm from one surface of the porous substrate. 5 ] ~ [ 9 ] The manufacturing method of the hydrogen separator in any one of.
[0019]
[ 11 The hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 μm [ 5 ] ~ [ 10 ] The manufacturing method of the hydrogen separator in any one of.
[0020]
[ 12 After the hydrogen selective permeable metal layer is formed, an alloy-forming metal layer is formed by electroplating on the surface of the porous substrate on one surface side of the hydrogen selective permeable metal layer. The alloy is formed by heating the permeable metal layer and the alloy-forming metal layer to form an alloyed hydrogen-selective metal layer composed of an alloy of a hydrogen-selective permeable metal and an alloy-forming metal. The hydrogen separation layer composed of the hydrogen selective permeable metal layer is disposed [ 5 ] ~ [ 11 ] The manufacturing method of the hydrogen separator in any one of.
[0021]
[ 13 The alloyed hydrogen permselective metal layer constituting the hydrogen separation layer is formed from a portion having a depth of 0.1 to 5 μm from one surface of the porous substrate. 12 ] The manufacturing method of the hydrogen separator as described in
[0022]
[ 14 The alloyed hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 μm. 12 ] Or [ 13 ] The manufacturing method of the hydrogen separator of description.
[0023]
Thus, according to the hydrogen separator of the present invention, the hydrogen separation layer disposed on the porous substrate has a predetermined depth from one surface of the porous substrate inside each of the pores of the porous substrate. Since the hydrogen separation layer is formed by the hydrogen selective permeable metal layer formed from the region, the hydrogen separation layer is held inside the pores of the porous substrate, and free expansion / contraction is suppressed. Even if a thermal cycle is applied to the separator, it is possible to suppress the separation of the hydrogen separation layer from the porous substrate or the generation of defects in the hydrogen separation layer. In addition, since the hydrogen separation layer is formed from a portion having a predetermined depth from one surface of the porous substrate, the hydrogen separation layer does not exist on the surface of the hydrogen separator. Even if it adheres to the surface of the metal, it does not come into contact with the hydrogen separation layer, and defects in the hydrogen separation layer can be suppressed.
[0024]
Further, according to the method for producing a hydrogen separator of the present invention, when an activation-treated substrate is produced by attaching an activated metal to a porous substrate, a portion having a predetermined depth from one surface of the porous substrate. Since the activated metal was attached to the inner wall of the pore with a predetermined thickness toward the other surface side of the porous substrate, and the hydrogen selective permeable metal layer was formed using the activated metal as a nucleus, hydrogen separation A layer is formed in each of the pores of the porous substrate at a predetermined thickness from a portion of a predetermined depth from one surface of the porous substrate toward the other surface side of the porous substrate. A hydrogen separator composed of a hydrogen selective permeable metal layer can be produced.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and is within the scope of the present invention. Based on this knowledge, it should be understood that design changes, improvements, etc. can be made as appropriate.
[0026]
FIG. 1 is a cross-sectional view schematically showing an embodiment of the hydrogen separator of the present invention in which a main part is enlarged by cutting along a plane perpendicular to the hydrogen separation layer.
[0027]
As shown in FIG. 1, the hydrogen separator 1 of the present embodiment includes a porous substrate 2 having a large number of pores 4 communicating from one surface 5 to another surface (not shown), and a porous structure. Hydrogen separation layer disposed on the substrate 2 and capable of selectively allowing only hydrogen out of a gas containing hydrogen flowing from one surface 5 side to flow out from the other surface (not shown) side. 3, and the hydrogen separation layer 3 is disposed inside each of the pores 4 of the porous substrate 2 from a portion 7 having a predetermined depth from one surface 5 of the porous substrate 2. It is characterized by comprising a hydrogen selective permeable metal layer 6 formed with a predetermined thickness W toward the surface (not shown) of the metal. The pores 4 of the porous substrate 2 are blocked by the hydrogen selective permeable metal 8 in the range of the predetermined thickness W, and the airtightness between the one surface 5 side and the other surface (not shown) side is improved. It is kept.
[0028]
Thus, since the hydrogen separation layer 3 constituted by the hydrogen selective permeable metal layer 6 does not exist on one surface 5 of the porous substrate 2 and enters the inside of the pores 4, Even if the thermal cycle is applied to the hydrogen separator 1 and the porous substrate 2 and the hydrogen separation layer 3 repeatedly expand and contract, the hydrogen separator 3 expands and contracts while being held in the pores 4. And the airtightness can be maintained. Further, since the hydrogen separation layer 3 is formed from the surface 7 of the porous substrate 2 to the other surface (not shown) side of the porous substrate 2 from the portion 7 having a predetermined depth, the porous substrate 2 is porous. Even if the pores 4 from one surface 5 of the substrate 2 to the portion 7 having a predetermined depth are not filled, and the metal fine powder adheres to the surface of the hydrogen separator 1, the hydrogen separation layer 3 can be prevented from being defective.
[0029]
The hydrogen selective permeable metal layer 6 constituting the hydrogen separation layer 3 is preferably formed from a portion having a depth of 0.1 to 5 μm from one surface 5 of the porous substrate 2. Furthermore, it is more preferable to form from the site | part of the depth of 0.3-2 micrometers. That is, the predetermined depth in the portion 7 having a predetermined depth from one surface 5 of the porous substrate 2 is 0.1 to 5 μm. When the predetermined depth is smaller than 0.1 μm, when the metal fine powder adheres to the surface of the hydrogen separator 1, it adheres to the hydrogen separation layer 3, and a defect may occur in the hydrogen separation layer 3. Further, if the predetermined depth is larger than 5 μm, a gas having a reduced hydrogen concentration (gas containing hydrogen) stays in the pores 4 from one surface 5 to the portion 7 having the predetermined depth. Separation efficiency may decrease.
[0030]
The predetermined thickness W of the hydrogen selective permeable metal layer 6 constituting the hydrogen separation layer 3 is preferably 1 to 5 μm. If the thickness is less than 1 μm, defects may easily occur in the hydrogen separation layer 3. If the thickness is more than 5 μm, the separation efficiency of hydrogen separation by the hydrogen separation layer 3 may be reduced.
[0031]
The hydrogen selective permeable metal layer constituting the hydrogen selective permeable metal layer 6 is preferably made of palladium or an alloy containing palladium.
[0032]
The porous substrate 2 is preferably a porous body mainly composed of ceramic. By using ceramic as a main component, the hydrogen separator 1 having excellent heat resistance, corrosion resistance, and the like and high mechanical strength can be obtained. The ceramic is not particularly limited, and any ceramic generally used as a hydrogen separator can be employed. Examples thereof include alumina, silica, silica-alumina, mullite, cordierite, zirconia and the like. As components other than ceramics, a small amount of components inevitably contained or components that are usually added may be contained. In addition to ceramic, carbon or porous glass can also be used. Note that the thickness of the porous substrate 2 is not particularly limited. It is sufficient that sufficient mechanical strength can be maintained in the use environment.
[0033]
The porous substrate 2 has a large number of fine pores 4 that are three-dimensionally continuous. The pore diameter of the pores 4 is preferably 0.003 to 2 μm, It is more preferable that it is 1 micrometer or less. When the pore diameter is less than 0.003 μm, the resistance when the gas passes may increase. On the other hand, when the pore diameter exceeds 2 μm, when the hydrogen selective permeable metal layer 6 is disposed by chemical plating when the hydrogen separator 1 of the present embodiment is manufactured, the hydrogen selective permeable metal 8 makes the finer. Since it becomes difficult to block | close the hole 4, it is not preferable.
[0034]
Further, it is preferable that the pores 4 of the porous substrate 2 have the same pore diameter. As a result, when the hydrogen selective permeable metal layer 6 is disposed by the above chemical plating, the plating solution easily enters the pores 4 without leaking, and the pores 4 not filled with the hydrogen selective permeable metal 8 are generated. Can avoid problems.
[0035]
Next, an embodiment of the method for producing a hydrogen separator of the present invention will be described in detail with reference to the drawings.
[0036]
FIG. 2 is an enlarged cross-sectional view of the vicinity of one surface of the porous substrate, schematically showing a state in which the activated metal is attached to the porous substrate in the method for producing a hydrogen separator according to the present embodiment. . FIG. 3 shows an activation metal deposited from one surface of the porous substrate to a predetermined depth in the activated metal deposited on the porous substrate in the method for producing a hydrogen separator according to the present embodiment. It is sectional drawing which expanded the vicinity of one surface of the porous substrate which shows the state which removed the metal typically. FIG. 4 is an enlarged cross-sectional view of the vicinity of one surface of a porous substrate, showing a hydrogen separator manufactured by the method for manufacturing a hydrogen separator of the present embodiment.
[0037]
In the method for producing a hydrogen separator according to the present embodiment, first, as shown in FIG. 2, an activation metal 29 is attached to one surface 25 of the porous substrate 22 and the inner wall of the pore 24 to activate the hydrogen separator. The metal adhesion base 20 is produced.
[0038]
Next, among the activated metals 29 attached to the obtained activated metal-attached substrate 20, the surface 25 of the porous substrate 22 and the inner wall of the pores 24 are predetermined from the surface 25 of the porous substrate 22. The activated metal 29 adhering to the portion 27 having a depth of 5 mm is removed, and the portion of the porous substrate 22 is removed from the portion 27 having a predetermined depth from one surface 25 of the porous substrate 22 as shown in FIG. An activation treatment substrate 30 having a predetermined thickness W toward the other surface (not shown) and having an activation metal 29 attached to the inner wall of the pore 24 is produced.
[0039]
Then, the obtained activated substrate 30 is subjected to chemical plating treatment using the activated metal 29 as a nucleus, and as shown in FIG. 4, hydrogen selective permeability is provided at the position where the activated metal 29 (see FIG. 3) is attached. By forming the metal layer 26, the inside of each of the pores 24 of the porous substrate 22, from a portion 27 having a predetermined depth from one surface 25 of the porous substrate 22, to the other surface of the porous substrate 22. A hydrogen separation layer 23 composed of a hydrogen selective permeable metal layer 26 formed with a predetermined thickness W toward the side (not shown) is disposed to obtain a hydrogen separator 40. The hydrogen selective permeable metal layer 26 constituting the hydrogen separation layer 23 is formed so that the pores 24 are filled with the hydrogen selective permeable metal 28 and closed, and a gas other than hydrogen does not pass through the pores 24. Yes.
[0040]
As described above, the activated metal adhering to the activated metal adhering substrate from the surface of the porous substrate up to a predetermined depth is removed, and then the chemical plating is performed. Since the hydrogen selective permeable metal layer is formed, the hydrogen separation layer can be disposed at a desired position inside the hydrogen separator.
[0041]
In the method for producing a hydrogen separator according to the present embodiment, when the activated metal 29 shown in FIG. 2 is attached to the porous substrate 22, the porous substrate 22 is immersed in a solution containing the activated metal 29 to obtain a porous material. A solution containing the activated metal 29 is attached to one surface 25 side of the porous substrate 22 and washed with water. At this time, the other surface (not shown) side of the porous substrate 22 may be decompressed, and the solution containing the activated metal 29 may be permeated to a desired site inside the pores 24 of the porous substrate 22. . Further, the activated metal 29 may be attached to the other surface (not shown) side of the porous substrate 22.
[0042]
As a method for attaching the activated metal 29, a compound containing a palladium divalent ion can be suitably used. As a method for attaching the activated metal 29 to the porous substrate 22, when palladium is provided as a hydrogen selective permeable metal, the porous substrate 22 is alternately formed by an aqueous hydrochloric acid solution of palladium chloride and an aqueous hydrochloric acid solution of tin chloride. It is preferable to immerse in.
[0043]
In the method for producing a hydrogen separator according to the present embodiment, an activated metal 29 attached to a portion 27 having a predetermined depth from one surface 25 of the porous substrate 22 shown in FIG. As a method of removing from the substrate 20, it is preferable to remove the activated metal adhesion substrate 20 by immersing it in an acidic solution and dissolving the activated metal 29 in the acidic solution. As the kind of acidic solution, it is preferable to use a mixed acid of hydrochloric acid and nitric acid. The total concentration (acid concentration) of hydrochloric acid (hydrogen chloride) and nitric acid in the mixed acid is preferably 40 to 75% by mass. The mass ratio of hydrogen chloride to nitric acid (hydrogen chloride / nitric acid) is preferably 1/6 to 2/7.
[0044]
The time for immersing the activated metal adhering substrate 20 in the acidic solution is not particularly limited, and can be appropriately determined depending on the composition and concentration of the acidic solution, but is preferably 10 to 25 seconds.
[0045]
As shown in FIG. 4, chemical activation is applied to the activation substrate 30 having the predetermined thickness W attached to the inner wall of the pore 24 of the porous substrate 22 as shown in FIG. In order to form the hydrogen selective permeable metal layer 26 at the position where the activated metal 29 (see FIG. 3) is attached, the activation substrate 30 shown in FIG. 3 contains the hydrogen selective permeable metal and the reducing agent. Immerse in plating solution. At this time, the activation substrate 30 is immersed so that one surface 25 side of the porous substrate 22 is in contact with the plating solution, and the pressure is reduced from the other surface (not shown) side of the porous substrate 22. It is preferable that the plating solution penetrates into the pores 24 of the porous substrate 22 to a position deeper than the position where the activated metal 29 is disposed. Then, when the plating solution penetrates into the pores 24, the hydrogen selective permeable metal is deposited with the activated metal 29 as a nucleus, and the hydrogen selective permeable metal layer 26 (see FIG. 4) is formed. As a result, as shown in FIG. 4, each of the pores 24 of the porous substrate 22 has a predetermined depth from the surface 27 of one surface of the porous substrate 22 to the other portions of the porous substrate 22. The hydrogen separator 40 can be obtained by disposing the hydrogen separation layer 23 composed of the hydrogen selective permeable metal layer 26 formed with a predetermined thickness W toward the surface (not shown). The penetration depth of the plating solution is controlled by adjusting the pressure difference between both surfaces (one surface 25 and the other surface) caused by the immersion time, the temperature of the plating solution, the reduced pressure applied to the porous substrate 22, and the like. be able to.
[0046]
The distance between a portion 27 having a predetermined depth from one surface 25 of the porous substrate 22 and the one surface 25 of the porous substrate 22 shown in FIG. Although it is not a thing, 0.1-5 micrometers is preferable. That is, the hydrogen permselective metal layer 26 constituting the hydrogen separation layer 23 is formed from a portion having a depth of 0.1 to 5 μm (a portion 27 having a predetermined depth) from one surface 25 of the porous substrate 22. It is preferable. If it is shallower than 0.1 μm, fine metal powder or the like may adhere to the hydrogen selective permeable metal. If it is deeper than 5 μm, the hydrogen concentration decreases from one surface 25 to the pores 24 to a predetermined depth 27. Gas (a gas containing hydrogen) may remain, and the hydrogen separation efficiency may decrease. A predetermined depth 27 from one surface 25 of the porous substrate 22 shown in FIGS. 2 and 3 is also formed at the same position.
[0047]
The predetermined thickness W of the hydrogen selective permeable metal layer 26 constituting the hydrogen separation layer 23 shown in FIG. 4 is particularly suitable if the hydrogen selective permeable metal layer 26 is less prone to defects and has good hydrogen permeability. Although not limited, 1-5 micrometers is preferable. If it is thinner than 1 μm, defects may easily occur in the hydrogen separation layer 23, and if it is thicker than 5 μm, the separation efficiency of hydrogen separation by the hydrogen separation layer 23 may be reduced.
[0048]
The porous substrate 22 shown in FIG. 4 is preferably a porous body mainly composed of ceramic. By using ceramic as a main component, the hydrogen separator 40 having excellent heat resistance, corrosion resistance, etc. and high mechanical strength can be obtained. The ceramic is not particularly limited, and any ceramic generally used as a hydrogen separator can be employed. Examples thereof include alumina, silica, silica-alumina, mullite, cordierite, zirconia and the like. In addition to ceramic, carbon or porous glass can also be used. Note that the thickness of the porous substrate 22 is not particularly limited. It is sufficient that sufficient mechanical strength can be maintained in the use environment.
[0049]
The porous substrate 22 has a large number of fine pores 24 that are three-dimensionally continuous. The pore diameter of the pores 24 is preferably 0.003 to 2 μm, It is more preferable that it is 1 micrometer or less. When the pore diameter is less than 0.003 μm, the resistance when the gas passes may increase. On the other hand, if the pore diameter exceeds 2 μm, it is difficult to block the pores 24 by the hydrogen selective permeable metal 28 when performing chemical plating in the method for producing a hydrogen separator of the present embodiment, which is not preferable.
[0050]
Further, it is preferable that the pores 24 of the porous substrate 22 have the same pore diameter. As a result, when the hydrogen selective permeable metal layer 26 is disposed by chemical plating, the plating solution easily enters the pores 24 without leaking, and the pores 24 that are not filled with the hydrogen selective permeable metal 28 are generated. Can be avoided.
[0051]
In the method for producing a hydrogen separator of the present embodiment, the hydrogen selective permeable metal layer constituting the hydrogen separation layer is preferably made of palladium or an alloy containing palladium. In order to make the hydrogen selective permeable metal layer made of an alloy containing palladium, after forming the hydrogen selective permeable metal layer by chemical plating of palladium by the manufacturing method described above, the hydrogen selective permeable metal is formed. The surface of the layer is further plated with silver to form an alloy-forming metal layer, and then heated to cause interdiffusion of palladium and silver to alloy the hydrogen selective permeable metal and the alloy-forming metal, It is preferable to form an alloyed hydrogen permselective metal layer. When silver is plated on the surface of the hydrogen selective permeable metal layer, electroplating is preferably performed using palladium constituting the hydrogen selective permeable metal layer as an electrode. At this time, the mass ratio of palladium to silver (palladium: silver) is preferably 90:10 to 70:30. The main purpose of alloying palladium is to prevent hydrogen embrittlement of palladium and to improve separation efficiency at high temperatures. In addition, by using silver as a metal other than palladium, embrittlement of palladium by hydrogen is more effectively prevented.
[0052]
The alloyed hydrogen permselective metal layer constituting the hydrogen separation layer is preferably formed from a portion having a depth of 0.1 to 5 μm from one surface of the porous substrate. If it is shallower than 0.1 μm, metal fine powder may adhere to the hydrogen selective permeable metal. If it is deeper than 5 μm, the hydrogen concentration decreases from one surface 5 to the pores 4 to a predetermined depth 7. Gas (a gas containing hydrogen) may remain, and the hydrogen separation efficiency may decrease.
[0053]
The alloyed hydrogen selective permeable metal layer constituting the hydrogen separation layer is preferably formed with a thickness of 1 to 5 μm. If the thickness is less than 1 μm, defects may easily occur in the hydrogen separation layer. If the thickness is more than 5 μm, the separation efficiency of hydrogen separation by the hydrogen separation layer may be reduced.
[0054]
【Example】
EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
[0055]
(Example 1)
As the porous substrate, a cylindrical asymmetric inorganic porous material (manufactured by α-alumina, manufactured by NGK Adrec Co., Ltd.) was used. This porous substrate has an outer diameter of 10 mm, an inner diameter of 7 mm, a length of 110 mm, and a pore diameter of 0.1 μm. The porous tube (porous substrate) was washed with water and then dried. Next, as a degreasing treatment, a solution containing 10% by volume of OPC370 manufactured by Okuno Pharmaceutical Co., Ltd. was maintained at 70 ° C., immersed for 5 minutes, and then washed with water.
[0056]
Next, the porous substrate was activated (first activation process). The cylindrical porous substrate was immersed in a solution containing 1% by volume of OPC pre-dip manufactured by Okuno Pharmaceutical Co., Ltd. for 2 minutes. Next, a solution containing 5% by volume of each of Inducer A and Inducer C manufactured by Okuno Pharmaceutical Co., Ltd. was kept at 50 ° C., immersed for 5 minutes, and then washed with water. Next, it was immersed for 5 minutes in a solution containing 15% by volume of Crister MU manufactured by Okuno Pharmaceutical Co., Ltd. Next, after immersing in a solution containing 3% by volume of Crister MU manufactured by Okuno Pharmaceutical Co., Ltd. for 1 minute, it was washed with water to obtain an activated metal-adhered substrate having palladium nuclei attached as the activated metal.
[0057]
Next, the surface of the activated metal-adhered substrate and a part of the palladium nucleus inside the pores were dissolved and washed with an acidic solution (acid treatment). The activated metal-adhered substrate was immersed in an acid solution having a volume ratio of hydrochloric acid (36% by mass), nitric acid (69% by mass) and water for 15 seconds, and then washed with water.
[0058]
Next, an activation process (second activation process) was performed again. The acid-washed activated metal adhesion substrate was immersed in a solution containing 15% by volume of Crister MU manufactured by Okuno Pharmaceutical Co., Ltd. for 5 minutes. Next, it was immersed in a solution containing 3% by volume of Crister MU manufactured by Okuno Pharmaceutical Co., Ltd. for 1 minute and washed with water to obtain an activation-treated substrate.
[0059]
Then, a hydrogen separation layer using palladium as a hydrogen selective permeable metal was formed by chemical plating treatment of the activation treatment substrate. In 1 L (liter) of water from which ions have been removed, [Pd (NH Three ) Four ] Cl 2 ・ H 2 O (5.4 g), 2Na · EDTA (67.2 g), ammonia water having an ammonia concentration of 28 mass% (651.3 mL) and H 2 NNH 2 ・ H 2 An aqueous solution to which O (0.64 mL) was added was prepared. Then, the temperature of the aqueous solution was controlled to 50 ° C., the outer surface of the activation-treated substrate was immersed in the aqueous solution, and the inside of the cylindrical shape of the activation-treated substrate was decompressed with a vacuum pump. The immersion time was 15 minutes, thereby obtaining a porous substrate in which a hydrogen separation layer made of palladium was formed only in a portion where palladium nuclei adhered inside the activated substrate.
[0060]
Here, when washing with an acidic solution, a thin (about 10 mm) sealing tape was wound around the outer peripheral surface of both ends of the cylindrical shape of the activated porous substrate to isolate it from the acidic solution. As a result, when the activated metal-adhered substrate is subjected to chemical plating treatment, it is possible to easily form a fine thin palladium film continuous with palladium deposited inside the pores of the porous substrate on the outer peripheral surfaces of both ends. it can. Then, this can be used as an electrode for electroplating in the next step and an airtight seal portion of the hydrogen separator.
[0061]
Next, silver was electroplated using the thin palladium films formed on the outer peripheral surfaces at both ends of the porous substrate as described above as electrodes, and the weight ratio of palladium to silver was adjusted to 80:20. And finally, it hold | maintained at 900 degreeC for 1 hour, it heat-processed, palladium and silver were mutually diffused, palladium and silver were alloyed, and the hydrogen separator (Example 1) was obtained. The microstructure of the obtained hydrogen separator is shown in FIG. FIG. 5 is a photomicrograph showing a cross section of the hydrogen separator 50 of the present example cut along a plane substantially perpendicular to the hydrogen separation layer 53. As shown in FIG. 5, the obtained hydrogen separator 50 has the hydrogen separation layer 53 from the surface 55 of the porous substrate 52 to a predetermined depth 57 inside the pores of the porous substrate 52. It can be seen that the hydrogen selective permeable metal layer 56 is formed with a predetermined thickness toward the other surface (not shown) of the porous substrate 52. From the measurement of the fluorescent X-ray intensity, the thickness of the hydrogen selective permeable metal layer 56 was 4.2 μm. Further, the thickness of the hydrogen selective permeable metal layer 56 according to the obtained micrograph (see FIG. 5) was a similar value.
[0062]
(Example 2)
In Example 1, the hydrogen separator was obtained in the same manner as in Example 1 except that the porous substrate on which the hydrogen separation layer was formed was obtained by setting the immersion time when the activation treatment substrate was subjected to the chemical plating treatment to 10 minutes. (Example 2) was obtained. The obtained hydrogen selective permeable metal layer is formed in the porous substrate from a position 0.5 μm deep from the surface of the porous substrate, and the hydrogen selective permeable metal layer is measured by measuring the hydrogen fluorescence X-ray intensity. The thickness of was 1.9 μm. Moreover, the thickness of the hydrogen selective permeable metal layer by a microphotograph (not shown) was a similar value.
[0063]
The hydrogen separator (Examples 1 and 2) thus obtained was subjected to an airtight test. Helium gas was introduced to the outside of the cylindrical hydrogen separator, held at a pressure of 900 kPa, and the amount of gas leaking into the cylindrical hydrogen separator (He leakage amount) was measured. The results are shown in the column of cycle number 0 in Table 1. Moreover, the thermal cycle test was done with the following method about the hydrogen separator (Examples 1 and 2).
[0064]
(Thermal cycle test)
The hydrogen separator in the hydrogen atmosphere was heated from room temperature to 500 ° C. and then cooled to room temperature. This heating / cooling cycle was defined as one cycle, and 100 cycles were performed. Table 1 shows the results of measuring the amount of He leakage after every 10 cycles and measuring the amount of He leakage after the thermal cycle test up to 100 cycles.
[0065]
(Comparative Example 1)
In Example 1, after the first activation treatment, the hydrazine treatment was performed without performing the acid treatment and the second activation treatment to obtain an activation-treated substrate. The activated substrate thus obtained was subjected to palladium chemical plating in the same manner as in Example 1 to obtain a hydrogen separator (Comparative Example 1). The obtained hydrogen selective permeable metal layer was formed on the surface of the porous substrate, and the thickness of the hydrogen selective permeable metal layer was 4.3 μm as measured by fluorescent X-ray intensity. Moreover, the thickness of the hydrogen selective permeable metal layer by a microphotograph (not shown) was a similar value. The hydrogen separation body thus obtained was subjected to the above airtightness test and thermal cycle test. The results are shown in Table 1.
[0066]
(Comparative Example 2)
In Comparative Example 1, a hydrogen separator was obtained in the same manner as in Comparative Example 1 except that the porous substrate on which the hydrogen separation layer was formed was obtained by setting the immersion time when the activation-treated substrate was chemically plated to 10 minutes. (Comparative Example 2) was obtained. The obtained hydrogen selective permeable metal layer was formed on the surface of the porous substrate, and the thickness of the hydrogen selective permeable metal layer was 2.0 μm as measured by fluorescent X-ray intensity. Moreover, the thickness of the hydrogen selective permeable metal layer by a microphotograph (not shown) was a similar value.
[0067]
[Table 1]
Figure 0004367693
[0068]
FIG. 5 shows that a hydrogen separator in which a hydrogen selective permeable metal layer is formed only inside the pores of the porous substrate can be produced by washing with the acidic solution after the activation treatment of the porous substrate. Further, from Table 1, the hydrogen separator of the present invention in which the hydrogen selective permeable metal layer is formed only inside the pores of the porous substrate is longer in the heating / cooling cycle than the conventional hydrogen separator. It can be seen that high airtightness can be maintained. Since the hydrogen separator of the present invention has a structure in which the hydrogen selective permeable metal layer is formed only inside the pores of the ceramic porous substrate, it suppresses the expansion of the hydrogen selective permeable metal layer and depends on the temperature raising and lowering cycle. Generation of defects can be suppressed. In addition, since the outer surface of the hydrogen separator is ceramic, the metal fine powder can be prevented from adhering to and reacting with the surface of the hydrogen selective permeable metal layer. As a result, the durability of the hydrogen separator can be greatly improved.
[0069]
【The invention's effect】
As described above, according to the hydrogen separator of the present invention, the hydrogen separation layer disposed on the porous substrate has a predetermined amount from one surface of the porous substrate inside each of the pores of the porous substrate. By being constituted by the hydrogen selective permeable metal layer formed from the depth part, the hydrogen separation layer is held inside the pores of the porous substrate, and it is suppressed from freely expanding and contracting, Even when a thermal cycle is applied to the hydrogen separator, it is possible to suppress the separation of the hydrogen separation layer from the porous substrate or the generation of defects in the hydrogen separation layer. In addition, since the hydrogen separation layer is formed from a portion having a predetermined depth from one surface of the porous substrate, the hydrogen separation layer hardly exists on the surface of the hydrogen separator. Even if it adheres to the surface of the body, it hardly comes into contact with the hydrogen separation layer, and it is possible to suppress the occurrence of defects in the hydrogen separation layer.
[0070]
Further, according to the method for producing a hydrogen separator of the present invention, when an activation-treated substrate is produced by attaching an activated metal to a porous substrate, a portion having a predetermined depth from one surface of the porous substrate. Since the activated metal was attached to the inner wall of the pore with a predetermined thickness toward the other surface side of the porous substrate, and the hydrogen selective permeable metal layer was formed using the activated metal as a nucleus, hydrogen separation A layer is formed in each of the pores of the porous substrate at a predetermined thickness from a portion of a predetermined depth from one surface of the porous substrate toward the other surface side of the porous substrate. A hydrogen separator composed of a hydrogen selective permeable metal layer can be produced.
[Brief description of the drawings]
FIG. 1 is a sectional view schematically showing an embodiment of a method for producing a hydrogen separator according to the present invention by cutting along a plane perpendicular to a hydrogen separation layer and enlarging a main part thereof.
FIG. 2 is an enlarged view of the vicinity of one surface of a porous substrate schematically showing a state in which an activated metal is attached to the porous substrate in one embodiment of the method for producing a hydrogen separator of the present invention. It is sectional drawing.
FIG. 3 shows an embodiment of the method for producing a hydrogen separator according to the present invention, wherein, among activated metals attached to a porous substrate, from one surface of the porous substrate to a portion having a predetermined depth. It is sectional drawing which expanded the vicinity of one surface of the porous substrate which shows the state which removed the activated metal which adhered.
FIG. 4 is an enlarged cross-sectional view of the vicinity of one surface of a porous substrate, showing a hydrogen separator manufactured in one embodiment of a method for manufacturing a hydrogen separator of the present invention.
FIG. 5 is a photomicrograph showing a cross section cut along a plane substantially perpendicular to the hydrogen separation layer in an example of the hydrogen separator of the present invention.
[Explanation of symbols]
1, 40, 50 ... hydrogen separator, 2, 22, 52 ... porous substrate, 3, 23, 53 ... hydrogen separation layer, 4, 24 ... pore, 5, 25, 55 ... one surface, 6, 26 , 56 ... Hydrogen selective permeable metal layer, 7, 27, 57 ... Site of predetermined depth, 8, 28 ... Hydrogen selective permeable metal, 20 ... Activated metal adhesion substrate, 29 ... Activated metal, 30 ... Active Treatment substrate, W: predetermined thickness.

Claims (14)

その一の表面から他の表面まで連通する多数の細孔を有する多孔質基体と、前記多孔質基体に配設された、前記一の表面側から流入する水素を含む気体のうち水素だけを選択的に透過させて前記他の表面側から流出させることが可能な水素分離層とを備える水素分離体であって、
前記水素分離層が、前記多孔質基体の前記細孔のそれぞれの内部に、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで形成された水素選択透過性金属層によって構成されてなることを特徴とする水素分離体。A porous substrate having a large number of pores communicating from one surface to another surface, and only hydrogen is selected from the gas including hydrogen flowing from the one surface side disposed on the porous substrate. A hydrogen separator comprising a hydrogen separation layer that can be permeated and allowed to flow out from the other surface side,
The hydrogen separation layer is disposed in each of the pores of the porous substrate from a portion having a depth of 0.1 to 5 μm from one surface of the porous substrate to the other surface of the porous substrate. A hydrogen separator comprising a hydrogen selective permeable metal layer formed with a predetermined thickness toward the side. 前記水素分離層を構成する前記水素選択透過性金属層が、１〜５μｍの厚さで形成されてなる請求項１に記載の水素分離体。 The hydrogen separator according to claim 1, wherein the hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 µm . 前記水素分離層を構成する前記水素選択透過性金属層が、パラジウム又はパラジウムを含有する合金からなる請求項１又は２に記載の水素分離体。 The hydrogen separator according to claim 1, wherein the hydrogen selective permeable metal layer constituting the hydrogen separation layer is made of palladium or an alloy containing palladium . 前記多孔質基体がセラミックを主成分としてなる請求項１〜３のいずれかに記載の水素分離体。The hydrogen separator according to claim 1, wherein the porous substrate is mainly composed of ceramic . その一の表面から他の表面まで連通する多数の細孔を有する多孔質基体と、前記多孔質基体に配設された、前記一の表面側から流入する水素を含む気体のうち水素だけを選択的に透過させて前記他の表面側から流出させることが可能な水素分離層とを備える水素分離体を製造する方法であって、
前記多孔質基体の表面及び前記細孔の内壁に、活性化金属を付着させて、活性化金属付着基体を作製し、
前記活性化金属付着基体に付着した前記活性化金属のうち、前記多孔質基体の表面、及び前記細孔の内壁の、前記多孔質基体の一の表面から所定の深さの部位までに付着した前記活性化金属を除去して、前記多孔質基体の一の表面から所定の深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで、前記細孔の内壁に前記活性化金属が付着した活性化処理基体を作製し、
前記活性化処理基体に前記活性化金属を核として化学メッキ処理して、前記活性化金属が付着した位置に前記水素選択透過性金属層を形成することにより、前記多孔質基体の前記細孔のそれぞれの内部に、前記多孔質基体の一の表面から所定の深さの部位から、前記多孔質基体の前記他の表面側に向かって所定の厚さで形成された水素選択透過性金属層によって構成された前記水素分離層を配設して、前記水素分離体を得ることを特徴とする水素分離体の製造方法。A porous substrate having a large number of pores communicating from one surface to another surface, and only hydrogen is selected from the gas including hydrogen flowing from the one surface side disposed on the porous substrate. A hydrogen separator comprising a hydrogen separation layer that is allowed to permeate and flow out from the other surface side,
An activated metal is adhered to the surface of the porous substrate and the inner walls of the pores to produce an activated metal-attached substrate,
Of the activated metal adhering to the activated metal adhering substrate, adhering to the surface of the porous substrate and the inner wall of the pore from one surface of the porous substrate to a predetermined depth. The activated metal is removed so that the inner wall of the pore has a predetermined thickness from a portion having a predetermined depth from one surface of the porous substrate toward the other surface side of the porous substrate. An activation treatment substrate with the activation metal attached thereto was prepared,
The activated substrate is subjected to chemical plating using the activated metal as a nucleus, and the hydrogen selective permeable metal layer is formed at the position where the activated metal is adhered, thereby forming the pores of the porous substrate. A hydrogen selective permeable metal layer formed at a predetermined thickness from a portion having a predetermined depth from one surface of the porous substrate to the other surface side of the porous substrate in each interior. A method for producing a hydrogen separator, wherein the hydrogen separator is obtained by disposing the configured hydrogen separation layer. 前記水素分離層を構成する前記水素選択透過性金属層が、パラジウム又はパラジウムを含有する合金からなる請求項５に記載の水素分離体の製造方法。The method for producing a hydrogen separator according to claim 5 , wherein the hydrogen selectively permeable metal layer constituting the hydrogen separation layer is made of palladium or an alloy containing palladium. 前記活性化金属付着基体から前記活性化金属を除去するときに、前記活性化金属付着基体を酸性溶液に浸漬して、前記活性化金属を酸性溶液に溶解させて除去する請求項５又は６に記載の水素分離体の製造方法。When removing the activated metal from the activated metal deposition substrate, the activated metal deposition substrate was immersed in an acidic solution, to claim 5 or 6 to remove the activated metal is dissolved in an acidic solution The manufacturing method of the hydrogen separator of description. 前記酸性溶液が、塩酸と硝酸とを混合した混酸である請求項７に記載の水素分離体の製造方法。The method for producing a hydrogen separator according to claim 7 , wherein the acidic solution is a mixed acid obtained by mixing hydrochloric acid and nitric acid. 前記多孔質基体が、セラミックを主成分としてなる請求項５〜８のいずれかに記載の水素分離体の製造方法。The method for producing a hydrogen separator according to any one of claims 5 to 8 , wherein the porous substrate comprises ceramic as a main component. 前記水素分離層を構成する前記水素選択透過性金属層を、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から形成する請求項５〜９のいずれかに記載の水素分離体の製造方法。Hydrogen according to the selective hydrogen permeable metal layer forming the hydrogen separation layer, in any one of claims 5-9 to form a part of the depth of 0.1~5μm from one surface of the porous substrate A method for producing a separated body. 前記水素分離層を構成する前記水素選択透過性金属層を、１〜５μｍの厚さで形成する請求項５〜１０のいずれかに記載の水素分離体の製造方法。The method for producing a hydrogen separator according to any one of claims 5 to 10 , wherein the hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 µm. 前記水素選択透過性金属層を形成した後に、前記水素選択透過性金属層の、前記多孔質基体の一の表面側の表面に、電気メッキにより合金形成用金属層を形成し、前記水素選択透過性金属層及び前記合金形成用金属層を加熱し、水素選択透過性金属と合金形成用金属との合金から構成される合金化された水素選択透過性金属層を形成することにより、前記合金化された水素選択透過性金属層から構成される前記水素分離層を配設する請求項５〜１１のいずれかに記載の水素分離体の製造方法。After the hydrogen selective permeable metal layer is formed, an alloy forming metal layer is formed by electroplating on the surface of the porous substrate on the surface side of the porous substrate, and the hydrogen selective permeable metal layer is formed. The alloying by heating the permeable metal layer and the alloy forming metal layer to form an alloyed hydrogen permeable metal layer composed of an alloy of a hydrogen permeable metal and an alloy forming metal. The method for producing a hydrogen separator according to any one of claims 5 to 11 , wherein the hydrogen separation layer composed of the hydrogen selective permeable metal layer is disposed. 前記水素分離層を構成する前記合金化された水素選択透過性金属層を、前記多孔質基体の一の表面から０．１〜５μｍの深さの部位から形成する請求項１２に記載の水素分離体の製造方法。13. The hydrogen separation according to claim 12 , wherein the alloyed hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed from a portion having a depth of 0.1 to 5 μm from one surface of the porous substrate. Body manufacturing method. 前記水素分離層を構成する前記合金化された水素選択透過性金属層を、１〜５μｍの厚さで形成する請求項１２又は１３に記載の水素分離体の製造方法。The method for producing a hydrogen separator according to claim 12 or 13 , wherein the alloyed hydrogen selective permeable metal layer constituting the hydrogen separation layer is formed with a thickness of 1 to 5 µm.
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JP6054683B2 (en) * 2012-08-29 2016-12-27 日本特殊陶業株式会社 Method for producing hydrogen separator
JP2014184381A (en) * 2013-03-22 2014-10-02 Ngk Spark Plug Co Ltd Hydrogen separation body
JP6474953B2 (en) * 2013-07-10 2019-02-27 日本特殊陶業株式会社 Hydrogen separator and hydrogen production apparatus using hydrogen separator
JP6219625B2 (en) * 2013-07-10 2017-10-25 日本特殊陶業株式会社 Hydrogen separator and method for producing the same
JP6199657B2 (en) * 2013-08-07 2017-09-20 日本特殊陶業株式会社 Hydrogen separator and method for producing the same
JP6208067B2 (en) * 2014-03-31 2017-10-04 公益財団法人地球環境産業技術研究機構 Method for producing composite having thin metal-filled layer inside porous substrate, and composite

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