JP2009213985A - Catalytic carrier and stainless steel material for depositing catalyst - Google Patents
Catalytic carrier and stainless steel material for depositing catalyst Download PDFInfo
- Publication number
- JP2009213985A JP2009213985A JP2008058802A JP2008058802A JP2009213985A JP 2009213985 A JP2009213985 A JP 2009213985A JP 2008058802 A JP2008058802 A JP 2008058802A JP 2008058802 A JP2008058802 A JP 2008058802A JP 2009213985 A JP2009213985 A JP 2009213985A
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- stainless steel
- roughened
- supported
- roughened surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 118
- 239000000463 material Substances 0.000 title claims abstract description 57
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 54
- 239000010935 stainless steel Substances 0.000 title claims abstract description 51
- 230000003197 catalytic effect Effects 0.000 title abstract description 14
- 238000000151 deposition Methods 0.000 title description 3
- 238000000034 method Methods 0.000 claims abstract description 29
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 23
- 230000003746 surface roughness Effects 0.000 claims abstract description 15
- 239000007864 aqueous solution Substances 0.000 claims abstract description 11
- 229910021578 Iron(III) chloride Inorganic materials 0.000 claims abstract description 10
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 claims abstract description 10
- 238000001179 sorption measurement Methods 0.000 claims abstract description 7
- 229910052743 krypton Inorganic materials 0.000 claims abstract description 6
- DNNSSWSSYDEUBZ-UHFFFAOYSA-N krypton atom Chemical compound [Kr] DNNSSWSSYDEUBZ-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 16
- 239000002436 steel type Substances 0.000 claims description 15
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 238000007747 plating Methods 0.000 claims description 6
- 239000011941 photocatalyst Substances 0.000 claims description 4
- 239000000126 substance Substances 0.000 abstract description 12
- 239000000243 solution Substances 0.000 abstract description 10
- 229910000963 austenitic stainless steel Inorganic materials 0.000 abstract description 3
- 230000008021 deposition Effects 0.000 abstract 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 21
- 238000007788 roughening Methods 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 239000007789 gas Substances 0.000 description 10
- 238000012360 testing method Methods 0.000 description 9
- 229910000831 Steel Inorganic materials 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 8
- 239000010959 steel Substances 0.000 description 8
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 238000005238 degreasing Methods 0.000 description 6
- 239000008151 electrolyte solution Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000000919 ceramic Substances 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- 238000009713 electroplating Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000000746 purification Methods 0.000 description 3
- POWFTOSLLWLEBN-UHFFFAOYSA-N tetrasodium;silicate Chemical compound [Na+].[Na+].[Na+].[Na+].[O-][Si]([O-])([O-])[O-] POWFTOSLLWLEBN-UHFFFAOYSA-N 0.000 description 3
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 2
- 238000003915 air pollution Methods 0.000 description 2
- QQHSIRTYSFLSRM-UHFFFAOYSA-N alumanylidynechromium Chemical compound [Al].[Cr] QQHSIRTYSFLSRM-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000005554 pickling Methods 0.000 description 2
- 229910052761 rare earth metal Inorganic materials 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 241000080590 Niso Species 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000004887 air purification Methods 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000004811 liquid chromatography Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Abstract
Description
本発明は、電解粗面化表面を持つステンレス鋼材からなる触媒担持体、およびその表面に触媒物質を担持させた触媒担持ステンレス鋼材に関する。 The present invention relates to a catalyst carrier made of a stainless steel material having an electrolytically roughened surface, and a catalyst-carrying stainless steel material having a catalyst material supported on the surface thereof.
近年、環境保全対策として、触媒機能を利用した汚染物質の浄化が様々な分野で実施されている。たとえば、ＴｉＯ2などの光触媒を利用して大気汚染を軽減する試みが多方面でなされている。また、大気汚染の一因となっているガソリン自動車の排ガスは、Ｐｔ触媒によって浄化されている。 In recent years, as an environmental conservation measure, purification of pollutants using a catalytic function has been carried out in various fields. For example, various attempts have been made to reduce air pollution using a photocatalyst such as TiO 2 . In addition, the exhaust gas of gasoline automobiles that contributes to air pollution is purified by a Pt catalyst.
一方、環境におよぼす影響を考慮した動力源として、各種の燃料電池が開発されている。燃料電池の燃料として使用される水素を精製するために、メタンガス等をＰｔ触媒によって改質する試みがなされている。 On the other hand, various fuel cells have been developed as a power source in consideration of the influence on the environment. In order to purify hydrogen used as fuel for fuel cells, attempts have been made to reform methane gas or the like with a Pt catalyst.
使用される触媒物質の種類は、その用途によって様々であるが、Ｐｔなどの貴金属を使用したり、貴金属でなくとも微細に調整した粉末を原料としたりすることから総じて高価なものとなる。そのため、使用する触媒の性能を最大限に利用するために、担持された触媒が反応物質に対して最大限に接触できるような工夫がなされている。 The type of catalyst material used varies depending on the application, but it is generally expensive because a noble metal such as Pt is used or a finely adjusted powder is used as a raw material instead of a noble metal. Therefore, in order to make the best use of the performance of the catalyst to be used, a contrivance is made so that the supported catalyst can make maximum contact with the reactant.
一般に、触媒担持体は、セラミックス系の基体上にウオッシュコート層を形成させ、触媒粉末を担持している。たとえば５００〜６００℃位の高温で触媒機能を発揮するＰｔ触媒用担持体には、アルミナ、シリカなどのセラミックス製のウオッシュコート層が形成される。担持体の原料である粉末を焼成し触媒担持体を形成する際にマイクロポアの存在する多孔質体とすることで触媒担持量を多くして、触媒活性を増大させている。また、近年、自動車の排ガス浄化用の触媒担持体としてステンレス鋼が使用されている。ステンレス鋼など金属製の触媒担持体は、耐衝撃性がセラミックス系の担持体より優れ薄肉化も可能であることから、軽量化やコンパクト化を図る上で有利であり、特に自動車などの移動体への搭載には好適である。 In general, a catalyst carrier has a washcoat layer formed on a ceramic base and carries catalyst powder. For example, a washcoat layer made of ceramics such as alumina and silica is formed on a support for Pt catalyst that exhibits a catalytic function at a high temperature of about 500 to 600 ° C. When the powder, which is the raw material of the carrier, is fired to form a catalyst carrier, the amount of catalyst supported is increased to increase the catalyst activity by forming a porous body having micropores. In recent years, stainless steel has been used as a catalyst carrier for purifying automobile exhaust gas. The catalyst support made of metal such as stainless steel has an impact resistance superior to that of the ceramic support and can be thinned. Therefore, it is advantageous in reducing the weight and size. It is suitable for mounting on.
しかし、ステンレス鋼など金属製の触媒担持体は、触媒を担持するための表面積を、マイクロポアを有するセラミックス製の触媒担持体のように大きくすることができず、触媒活性が劣るといった問題点があった。 However, the catalyst support made of metal such as stainless steel has a problem that the surface area for supporting the catalyst cannot be increased as the catalyst support made of ceramics having micropores, and the catalytic activity is inferior. there were.
金属製の触媒担持体においては、特にステンレス鋼は、高温での耐酸化性に優れることから、ステンレス鋼の箔をコルゲート加工してハニカム状のフレームを形成し、そのフレームに触媒物質を把持するためのアルミナ（γ−Ａｌ2Ｏ3）をコーティングして、乾燥焼結した後、触媒コーティングを施すことにより、触媒物質をステンレス鋼表面に担持させ、触媒コンバータを得ている。ところが上記ステンレス鋼製のフレームはアルミナとの密着性が必ずしも十分でなく、そのため、種々の改良が試みられている。 In a metal catalyst carrier, stainless steel, in particular, has excellent oxidation resistance at high temperatures. Therefore, a stainless steel foil is corrugated to form a honeycomb-like frame, and the catalyst material is held on the frame. After coating with alumina (γ-Al 2 O 3 ) for drying and sintering, the catalyst material is supported on the stainless steel surface by applying the catalyst coating to obtain a catalytic converter. However, the stainless steel frame does not necessarily have sufficient adhesion to alumina, and various improvements have been attempted.
例えば、その一例として、Ａｌを３〜８質量％含有するＡｌ含有ステンレス鋼を用い、このステンレス鋼を焼きなまし後にコルゲート加工し、成形後、更に熱処理して鋼中のＡｌを利用してステンレス鋼表面にα−Ａｌ2Ｏ3ウイスカー（針状結晶）を生成させ、その針状結晶の上にγ−Ａｌ2Ｏ3をコーティングする方法が知られている（特許文献１）。 For example, as an example, an Al-containing stainless steel containing 3 to 8% by mass of Al is used, and this stainless steel is annealed and then corrugated, formed, and further heat-treated to utilize the Al in the steel surface. There is known a method in which α-Al 2 O 3 whiskers (needle crystals) are formed on the substrate and γ-Al 2 O 3 is coated on the needle crystals (Patent Document 1).
この他、α−Ａｌ2Ｏ3ウイスカーの生成を促進するため上記Ａｌ含有ステンレス鋼を予めＣＯ2雰囲気等で加熱処理する方法（特許文献２）、あるいはステンレス鋼の成分にＺｒ、Ｙ等を添加し、機械的強度や高温クリープ特性を改善する方法（特許文献３、４）等が知られている。 In addition, in order to promote the formation of α-Al 2 O 3 whiskers, the Al-containing stainless steel is preheated in a CO 2 atmosphere or the like (Patent Document 2), or Zr, Y, etc. are added to the stainless steel components. In addition, methods for improving mechanical strength and high temperature creep characteristics (Patent Documents 3 and 4) are known.
ところが、ステンレス鋼を用いて触媒コンバータのフレームを形成する上記従来方法は、何れも高Ａｌ含有ステンレス鋼を用い、ステンレス鋼の加熱処理により鋼中のＡｌを利用して鋼表面にα−Ａｌ2Ｏ3を生成させるものであり、製造工程が煩雑である。 However, all of the above conventional methods for forming the catalytic converter frame using stainless steel use high Al-containing stainless steel, and heat treatment of stainless steel utilizes Al in the steel to form α-Al 2 on the steel surface. O 3 is generated, and the manufacturing process is complicated.
また、特許文献５には鉄基合金箔からなるハニカムをγ−Ａｌ2Ｏ3またはγ−Ａｌ2Ｏ3とα−Ａｌ2Ｏ3をベースとするＡｌ拡散剤またはＡｌ−Ｃｒ複合拡散剤に埋没させ、７００〜９５０℃で４〜２０時間、無酸化雰囲気中で熱処理することにより、ＡｌまたはＡｌ−Ｃｒの複合拡散浸透処理と波板／平板の接合を行い、かつ多孔質なハニカム表面を得る方法が開示されている。しかし、この方法においても拡散剤に基材を埋没させて長時間加熱することが必要であり、工程が煩雑である。 In Patent Document 5, a honeycomb made of an iron-based alloy foil is used as an Al diffusing agent based on γ-Al 2 O 3 or γ-Al 2 O 3 and α-Al 2 O 3 or an Al-Cr composite diffusing agent. It is buried and heat-treated at 700 to 950 ° C. for 4 to 20 hours in a non-oxidizing atmosphere to perform Al or Al—Cr composite diffusion penetration treatment and corrugated plate / plate joining, and to form a porous honeycomb surface. A method of obtaining is disclosed. However, even in this method, it is necessary to immerse the base material in the diffusing agent and heat for a long time, and the process is complicated.
本発明はこのような現状に鑑み、煩雑な工程によらず簡単に触媒物質を担持させることができ、かつ、担持後も触媒活性を発揮させやすい多孔状の表面形態が容易に得られるようなステンレス鋼製触媒担持体を提供することを目的とする。また、この触媒担持体に触媒物質を担持させた合理的な構成の触媒担持ステンレス鋼材を提供することを目的とする。 In view of such a current situation, the present invention can easily support a catalyst material regardless of complicated steps, and can easily obtain a porous surface form that easily exhibits catalytic activity even after support. An object is to provide a stainless steel catalyst carrier. Another object of the present invention is to provide a catalyst-supported stainless steel material having a rational structure in which a catalyst substance is supported on the catalyst support.
上記目的は、クリプトンガス吸着法で測定される完全平滑面対する表面積増加率が３〜１０であり、分解能０.０１μｍの走査型レーザー顕微鏡で一辺が５０μｍ以上の矩形の表面領域を測定したときの面粗さＳＰａが０.３μｍ以上である電解粗面化表面を持つステンレス鋼材からなる触媒担持体によって達成される。前記電解粗面化表面は、電解によって生じたピットによって構成されており、例えば塩化第二鉄水溶液中での交番電解によって形成されるものである。前記ステンレス鋼材としては、ＪＩＳ Ｇ４３０５に規定される公知のオーステナイト系鋼種またはフェライト系鋼種が適用できる。 The above-mentioned purpose is when the surface area increase rate with respect to a completely smooth surface measured by the krypton gas adsorption method is 3 to 10, and when a rectangular surface region having a side of 50 μm or more is measured with a scanning laser microscope having a resolution of 0.01 μm. This is achieved by a catalyst carrier made of a stainless steel material having an electrolytically roughened surface with a surface roughness SPa of 0.3 μm or more. The electrolytic roughened surface is composed of pits generated by electrolysis, and is formed by, for example, alternating electrolysis in a ferric chloride aqueous solution. As the stainless steel material, a well-known austenitic steel type or ferritic steel type specified in JIS G4305 can be applied.
ここで、「完全平滑面に対する表面積増加率」とは、粗面化表面の一定の測定領域についてクリプトンガス吸着法によって測定される表面積Ｓと、その測定領域の面積Ｓ0の比の値、Ｓ／Ｓ0を意味する。「面粗さＳＰａ」は、ＪＩＳ Ｂ０６０１−２００１に規定される断面曲線の算術平均高さＰａを一定面積の表面領域について測定し、その平均値をとったものである。具体的には、ＳＰａは走査型レーザー顕微鏡により測定される三次元表面プロファイルのデータを解析することにより求まる面粗さパラメータの１つであり、断面曲面の平均面に対する断面曲面の標高の絶対値の平均値を意味する。三次元表面プロファイルを測定する表面領域は、一辺が５０μｍ以上の矩形の表面領域とする。すなわち５０μｍ×５０μｍ以上の測定面積を確保する。 Here, the “surface area increase rate with respect to a completely smooth surface” is a ratio value of the surface area S measured by the krypton gas adsorption method for a certain measurement region of the roughened surface and the area S 0 of the measurement region, S / S 0 is meant. “Surface roughness SPa” is obtained by measuring the arithmetic average height Pa of the cross-sectional curve defined in JIS B0601-2001 for a surface area of a certain area and taking the average value. Specifically, SPa is one of surface roughness parameters obtained by analyzing data of a three-dimensional surface profile measured by a scanning laser microscope, and the absolute value of the elevation of the cross-sectional curved surface with respect to the average surface of the cross-sectional curved surface Mean value of The surface region for measuring the three-dimensional surface profile is a rectangular surface region having a side of 50 μm or more. That is, a measurement area of 50 μm × 50 μm or more is ensured.
また本発明では、上記の触媒担持体の粗面化表面を構成しているピット壁に、触媒物質を付着させることにより、触媒物質を担持させた状態の粗面化表面を形成した触媒担持ステンレス鋼材が提供される。具体的には、
（i）Ｐｔめっきを施すことにより、Ｐｔ触媒を担持させた状態の粗面化表面を形成した触媒担持ステンレス鋼材、
（ii）ＴｉＯ2をコーティングすることにより、ＴｉＯ2光触媒を担持させた状態の粗面化表面を形成した触媒担持ステンレス鋼材、
を挙げることができる。
In the present invention, the catalyst-carrying stainless steel having a roughened surface in which the catalyst material is supported is formed by adhering the catalyst material to the pit walls constituting the roughened surface of the catalyst carrier. Steel is provided. In particular,
(I) a catalyst-carrying stainless steel material having a roughened surface with a Pt catalyst carried thereon by applying Pt plating;
(Ii) by coating the TiO 2, the catalyst-carrying stainless steel forming the roughened surface state obtained by carrying TiO 2 photocatalyst,
Can be mentioned.
「ピット壁」は、粗面化表面を構成している個々のピットの表面であり、開口部が隣接するピットの間に形成される「稜」の部分もピット壁の一部とみなされる。 The “pit wall” is the surface of individual pits constituting the roughened surface, and the “ridge” portion formed between adjacent pits is also considered as a part of the pit wall.
本発明によれば、触媒物質の担持を容易な工程で行うことができるステンレス鋼製の触媒担持体が提供された。この触媒担持体は、従来のステンレス鋼製触媒担持体と比べ、担持面積が格段に増大しているため、担持後の触媒性能が大幅に向上する。また、ステンレス鋼材を基材とするものであるから、セラミックス製のものに比べ振動や衝撃に対する耐久性が高い。さらにコスト面でも、従来のステンレス鋼製ハニカム担持体やセラミックス担持体に対して有利であると考えられる。 According to the present invention, a catalyst carrier made of stainless steel capable of carrying a catalyst material in an easy process is provided. Since this catalyst support has a significantly increased support area compared to a conventional stainless steel catalyst support, the catalyst performance after support is greatly improved. Moreover, since it uses a stainless steel material as a base material, its durability against vibration and impact is higher than that of a ceramic material. Further, in terms of cost, it is considered to be advantageous over conventional stainless steel honeycomb supports and ceramic supports.
触媒活性を大きくするためには、反応に供する物質と接触する触媒の面積を大きくすることが必要である。一方で触媒物質を有効に利用するためには、触媒担持体の表面全面に薄く均一に担持する必要がある。触媒のコーティング面積を大きくするためには、触媒担持体の実表面積を大きくすることが重要である。 In order to increase the catalytic activity, it is necessary to increase the area of the catalyst in contact with the substance to be subjected to the reaction. On the other hand, in order to effectively use the catalyst substance, it is necessary to carry it thinly and uniformly on the entire surface of the catalyst carrier. In order to increase the coating area of the catalyst, it is important to increase the actual surface area of the catalyst support.
金属製の触媒担持体の場合は、表面を粗面化することによって実表面積を増大させることができる。ただし、微細なピットを高密度で形成したものでなければ、実表面積を増大させるメリットに乏しい。 In the case of a metal catalyst carrier, the actual surface area can be increased by roughening the surface. However, unless fine pits are formed at high density, the merit of increasing the actual surface area is poor.
種々検討の結果、ステンレス鋼を基材として、その表面を塩化第二鉄水溶液中での交番電解により粗面化した場合に、触媒担持体として極めて有効な実表面積の増大効果が得られることが確認された。 As a result of various studies, when the surface is roughened by alternating electrolysis in a ferric chloride aqueous solution using stainless steel as a base material, it is possible to obtain an extremely effective increase in actual surface area as a catalyst carrier. confirmed.
〔ステンレス鋼〕
本願において「ステンレス鋼」は、Ｃｒ含有量が１０.５質量％以上の鋼をいう（ＪＩＳ Ｇ０２０３の番号４２０１）。触媒担持体としては、用途に応じて既存鋼種の中から適切な耐食性レベルの鋼種を選択することができる。例えばＪＩＳ Ｇ４３０５に規定されるオーステナイト系鋼種またはフェライト系鋼種に相当するものを選択することができる。具体的にはオーステナイト系鋼種としてはＳＵＳ３０４系の汎用鋼種の他、ＳＵＳ３１０系、ＳＵＳ３１５系、ＳＵＳ３１６系、ＳＵＳ３１７系等の鋼種が挙げられる。フェライト系鋼種としてはＳＵＳ４３０系の汎用鋼種の他、ＳＵＳ４３６系、ＳＵＳ４４４、ＳＵＳ４４５系等の鋼種が挙げられる。
〔Stainless steel〕
In the present application, “stainless steel” refers to steel having a Cr content of 10.5 mass% or more (number 4201 of JIS G0203). As the catalyst support, a steel type having an appropriate corrosion resistance level can be selected from existing steel types according to the application. For example, a material corresponding to an austenitic steel type or a ferritic steel type specified in JIS G4305 can be selected. Specifically, examples of the austenitic steel types include steel types such as SUS310 series, SUS315 series, SUS316 series, and SUS317 series in addition to SUS304 series general-purpose steel grades. Examples of the ferritic steel types include SUS430-based, SUS444, and SUS445-based steel types in addition to SUS430 general-purpose steel types.
また、ＪＩＳ Ｇ４３０５に規定されるオーステナイト系鋼種またはフェライト系鋼種をベースとして、用途に応じて、Ａｌ：５質量％以下、Ｔｉ：１質量％以下、Ｎｂ：１質量％以下、Ｖ：１質量％以下、Ｂ：１質量％以下、Ｃａ：０.１質量％以下、Ｍｇ：０.１質量％以下、Ｙ：０.１質量％以下、ＲＥＭ（希土類元素）：０.１質量％以下の１種以上を含有させた組成のステンレス鋼を採用することができる。 Further, based on the austenitic steel type or ferritic steel type specified in JIS G4305, Al: 5% by mass or less, Ti: 1% by mass or less, Nb: 1% by mass or less, V: 1% by mass, depending on the application. Hereinafter, B: 1% by mass or less, Ca: 0.1% by mass or less, Mg: 0.1% by mass or less, Y: 0.1% by mass or less, REM (rare earth element): 0.1% by mass or less Stainless steel having a composition containing at least seeds can be employed.
〔粗面化表面〕
本発明の触媒担持体においては、粗面化表面の第１の要件として、クリプトンガス吸着法で測定される完全平滑面に対する表面積増加率が３〜１０であることが要求される。この規定は、粗面化形態を表面積の観点から捉えたものである。触媒担持体では反応に供する物質と接触する触媒物質の面積が、反応の促進に大きく影響するからである。発明者らの検討の結果、上記の完全平滑面に対する表面積増加率（以下、単に「表面積増加率」ということがある）が３未満の場合は、触媒性能を向上させるのに不十分であり、また粗面化処理に要する工程やコストを考慮するとメリットに乏しい。一方、電解処理によって表面積増加率が１０を超えるような粗面化表面を得るには困難を伴うことが多い。また、そのような非常に高い表面積増加率の電解粗面化表面では開口径の小さい極めて微細なピットが高密度に形成されている状態となる。この場合、触媒物質の担持によって占領されるピット内部の体積割合が増大するので、ピット内部に残される空隙の割合が減少することになり、却って反応に供する物質と触媒物質との接触が阻害される傾向が大きくなることも懸念される。
(Roughened surface)
In the catalyst carrier of the present invention, the first requirement for the roughened surface is that the surface area increase rate with respect to the completely smooth surface measured by the krypton gas adsorption method is 3 to 10. This rule captures the roughened form from the viewpoint of surface area. This is because in the catalyst carrier, the area of the catalyst substance that comes into contact with the substance to be subjected to the reaction greatly affects the promotion of the reaction. As a result of the study by the inventors, when the surface area increase rate with respect to the completely smooth surface (hereinafter sometimes simply referred to as “surface area increase rate”) is less than 3, it is insufficient to improve the catalyst performance, Further, considering the process and cost required for the roughening treatment, the merit is poor. On the other hand, it is often difficult to obtain a roughened surface whose surface area increase rate exceeds 10 by electrolytic treatment. In addition, on such an electrolytically roughened surface having a very high surface area increase rate, extremely fine pits having a small opening diameter are formed at a high density. In this case, since the volume ratio inside the pit occupied by the loading of the catalyst substance increases, the ratio of the voids left inside the pit decreases, and the contact between the substance used for the reaction and the catalyst substance is hindered. There is also a concern that this tendency will increase.
粗面化表面の第２の要件として、分解能０.０１μｍの走査型レーザー顕微鏡で一辺が５０μｍ以上の矩形の表面領域を測定したときの面粗さＳＰａが０.３μｍ以上であることが要求される。面粗さＳＰａはピットの深さ方向の形状を大きく反映したパラメータである。概念的にはＳＰａが大きいほど、深いピットが数多く形成されていることになる。発明者らは種々検討の結果、上述の表面積増加率が前記規定範囲であるとともに、ＳＰａが０.３μｍ以上となるような形態の電解粗面化表面を形成することが、触媒担持後に優れた触媒活性を発揮せるうえで極めて有効であることを見出した。表面積増加率が上記範囲を満たす大きな値をとるにも拘わらずＳＰａが０.３μｍを下回るような場合には、比較的浅いピットによって大きな表面積が確保されていることを意味し、つまりそのときのピット形状は非常に微細な状態となっていると考えられる。このような粗面化形態では触媒物質を担持させた状態でピット内部に残される空隙の割合が減少してしまい、触媒活性を十分に発揮させることが難しくなる。なお、ＳＰａの上限は電解粗面化によって実現可能な範囲に必然的に制約されるので、特に規定する必要はないが、ＳＰａが概ね１μｍ以下の範囲で良好な結果が得られることが確認されている。 The second requirement for the roughened surface is that the surface roughness SPa when measuring a rectangular surface region with a side of 50 μm or more with a scanning laser microscope having a resolution of 0.01 μm is 0.3 μm or more. The The surface roughness SPa is a parameter that largely reflects the shape of the pit in the depth direction. Conceptually, the larger the SPa, the more deep pits are formed. As a result of various studies, the inventors found that the above-mentioned surface area increase rate is within the above specified range and that an electrolytically roughened surface having an SPa of 0.3 μm or more was formed after supporting the catalyst. It was found to be extremely effective in exhibiting catalytic activity. When SPa is less than 0.3 μm even though the surface area increase rate is a large value satisfying the above range, it means that a large surface area is secured by relatively shallow pits. The pit shape is considered to be very fine. In such a roughened form, the ratio of the voids left inside the pit in a state where the catalyst substance is supported is reduced, and it becomes difficult to sufficiently exhibit the catalytic activity. The upper limit of SPa is inevitably limited to the range that can be realized by electrolytic surface roughening, and thus it is not necessary to specify in particular, but it has been confirmed that good results can be obtained when SPa is approximately 1 μm or less. ing.
〔電解粗面化〕
電解粗面化に供するステンレス鋼材としては、一般的な酸洗仕上げ材や調質圧延仕上げ材などが適用可能である。電解粗面化処理に供する際には、前処理として通常の電解脱脂を行うことが好ましく、あるいは更に必要に応じて塩酸酸洗を実施することができる。
[Electrolytic roughening]
As the stainless steel material used for the electrolytic surface roughening, a general pickling finish material or a temper rolled finish material can be applied. When subjecting to an electrolytic surface roughening treatment, it is preferable to carry out a normal electrolytic degreasing as a pretreatment, or a hydrochloric acid pickling can be carried out if necessary.
上記のような粗面化形態を得るためには、塩化第二鉄水溶液中での交番電解処理が好適に適用できる。その粗面化メカニズムを簡単に説明する。電解液中でステンレス鋼板を交番電解するとまず、アノード電解によりピットが形成され、次のカソード電解でＨ2が発生する。このとき電解液中に、Ｆｅ3+が含まれていると、まだピットが形成されていないフラットな表面部に比べてピット内部では、一時的にＦｅ3+＋３ＯＨ-→Ｆｅ(ＯＨ)3の反応が起こる領域までｐＨが上昇し、この時にピット内壁は、Ｆｅ(ＯＨ)3に覆われ保護される。このため、次のアノード電解では、ピット内部よりもＨ2発生により活性化されているフラットな表面が優先的に溶解され、この繰り返しによって、比較的短時間に微細なピットがステンレス鋼表面にほぼ形成される。 In order to obtain the roughened form as described above, an alternating electrolytic treatment in a ferric chloride aqueous solution can be suitably applied. The roughening mechanism will be briefly described. When the stainless steel plate is alternately electrolyzed in the electrolytic solution, first, pits are formed by anode electrolysis, and H 2 is generated in the next cathode electrolysis. At this time, if Fe 3+ is contained in the electrolytic solution, Fe 3+ + 3OH − → Fe (OH) 3 is temporarily inside the pit as compared with the flat surface portion where the pit is not yet formed. The pH rises to the region where the reaction takes place, and at this time, the inner wall of the pit is covered and protected by Fe (OH) 3 . For this reason, in the next anode electrolysis, the flat surface activated by the generation of H 2 is preferentially dissolved over the inside of the pit, and by repeating this, fine pits are almost completely formed on the stainless steel surface in a relatively short time. It is formed.
電解液のエッチング力が弱いと浅めのピットが形成されやすく、エッチング力が増すにつれて半球状あるいは、鍵穴状といったピット開口部の割には深さのあるピットが形成されるようになる。これはエッチング力を強めるとステンレス鋼板の不動態化作用が低下し、深さ方向へのピット成長が促進されるためと考えられる。 When the etching force of the electrolytic solution is weak, shallow pits are likely to be formed, and as the etching force increases, pits having a depth are formed in relation to the pit openings such as a hemispherical shape or a keyhole shape. This is thought to be because, when the etching force is increased, the passivating action of the stainless steel plate is lowered and the pit growth in the depth direction is promoted.
Ｆｅ3+を含まない塩化第一鉄、硝酸、塩酸、硫酸などの電解液中では、上記メカニズムを利用した電解粗面化が行われない。さらに本発明では、ステンレス鋼を対象とするので、電解液中にはステンレス鋼の酸化作用を促進するＮＯ3―、ＳＯ4 2-といったイオンが含まれていないことも、孔食、すなわちピットの形成を容易にさせ、粗面化処理時間を短時化するために重要となる。このような観点から、電解液としては、Ｆｅ3+を含む塩化第二鉄溶液を使用するのが好ましい。 In an electrolytic solution such as ferrous chloride not containing Fe 3+ , nitric acid, hydrochloric acid, and sulfuric acid, electrolytic surface roughening using the above mechanism is not performed. Furthermore, in the present invention, since stainless steel is targeted, it is possible that the electrolyte does not contain ions such as NO 3− and SO 4 2− that promote the oxidation action of stainless steel. This is important for facilitating the formation and shortening the roughening treatment time. From such a viewpoint, it is preferable to use a ferric chloride solution containing Fe 3+ as the electrolytic solution.
電解液の濃度や電解条件は、ステンレス鋼種に応じて上述の粗面化形態が得られる適正範囲に設定する必要がある。例えば、フェライト系ステンレス鋼の場合、Ｆｅ3+濃度５〜５０ｇ／Ｌの塩化第二鉄水溶液中で、アノード電解時の電流密度１.０〜１０.０ｋＡ／ｍ2、カソード電解時の電流密度０.１〜２.０ｋＡ／ｍ2とした０.５〜５Ｈｚの交番電解を１０〜１２０秒間施す条件範囲において、最適条件を定めるとよい。一方、オーステナイト系ステンレス鋼の場合は、Ｆｅ3+濃度４０〜１２０ｇ／Ｌの塩化第二鉄溶液中で、アノード電解時の電流密度１.０〜１０.０ｋＡ／ｍ2、カソード電解時の電流密度０.３〜２.０ｋＡ／ｍ2とした０.５〜５Ｈｚの交番電解を１０〜１２０秒間施す条件範囲において、最適条件を定めるとよい。 It is necessary to set the concentration of the electrolytic solution and the electrolysis conditions in an appropriate range in which the above roughened form can be obtained according to the stainless steel type. For example, in the case of ferritic stainless steel, the current density at the time of anode electrolysis is 1.0 to 10.0 kA / m 2 and the current density at the time of cathode electrolysis in a ferric chloride aqueous solution having an Fe 3+ concentration of 5 to 50 g / L. Optimum conditions may be determined in a condition range in which alternating electrolysis of 0.5 to 5 Hz, which is 0.1 to 2.0 kA / m 2, is performed for 10 to 120 seconds. On the other hand, in the case of austenitic stainless steel, the current density during anode electrolysis is 1.0 to 10.0 kA / m 2 and the current during cathode electrolysis in a ferric chloride solution having an Fe 3+ concentration of 40 to 120 g / L. Optimum conditions may be determined in a condition range in which alternating electrolysis of 0.5 to 5 Hz with a density of 0.3 to 2.0 kA / m 2 is performed for 10 to 120 seconds.
〔触媒物質の担持〕
本発明の触媒担持体の粗面化表面を構成しているピット壁に、触媒物質を付着させることにより、触媒物質を担持させた状態の粗面化表面を形成した触媒担持ステンレス鋼材を得ることができる。触媒担持方法としては、触媒を分散させた水溶液中に担持体を浸漬し引上げる方法、触媒を分散させた水溶液に混合して、スプレーで触媒担持体に塗布後、乾燥固化する方法、触媒を電気めっき液中に混合し、電気めっき法で触媒担持体に触媒を析出させる方法、気相法により触媒金属または化合物を触媒担持体に蒸着する方法等がある。
[Supporting catalyst material]
Obtaining a catalyst-carrying stainless steel material having a roughened surface in a state in which the catalyst material is supported by attaching the catalyst material to the pit wall constituting the roughened surface of the catalyst support of the present invention Can do. The catalyst support method includes a method of immersing and lifting the support in an aqueous solution in which the catalyst is dispersed, a method in which the catalyst is mixed with the aqueous solution in which the catalyst is dispersed, applied to the catalyst support by spraying, and then dried and solidified. There are a method of mixing in an electroplating solution and depositing a catalyst on the catalyst support by an electroplating method, a method of depositing a catalyst metal or a compound on the catalyst support by a vapor phase method, and the like.
上記いずれの方法においても触媒物質は、極薄くコーティングすることが好ましい。コーティング量が過剰に多くなると、余剰の触媒は効力を発揮せず無駄となるばかりでなく、電解粗面化処理によって形成した凹凸が緩和され、かえって触媒反応効率が低下する。したがって、触媒担持体の粗面化表面を構成しているピット壁に必要最小限の触媒物質を薄く付着させ、付着後にもピット形状が残存して、反応に供する物質との接触面積が十分に確保されるようにすることが理想的である。 In any of the above methods, the catalyst material is preferably coated very thinly. When the coating amount is excessively large, the excess catalyst is not used effectively and is wasted, and the unevenness formed by the electrolytic surface roughening treatment is alleviated, and the catalytic reaction efficiency is lowered. Therefore, the minimum necessary amount of catalytic material is thinly attached to the pit wall constituting the roughened surface of the catalyst carrier, and the pit shape remains even after the attachment, so that the contact area with the material to be used for the reaction is sufficient. Ideally, it should be ensured.
自動車排ガスの浄化触媒をはじめ、種々の用途に適用される代表的な触媒物質として、Ｐｔ（白金）が挙げられる。本発明の触媒担持体は金属であるから、電気めっき法によりその粗面化表面に効率良くＰｔ触媒をコーティングすることが可能である。 Pt (platinum) is mentioned as a typical catalyst material applied to various uses including a purification catalyst for automobile exhaust gas. Since the catalyst carrier of the present invention is a metal, it is possible to efficiently coat the roughened surface with a Pt catalyst by electroplating.
大気浄化、脱臭、抗菌、浄水等の目的で使用される代表的な触媒物質として、光触媒であるＴｉＯ2（酸化チタン）が挙げられる。この場合は、ＴｉＯ2粒子を分散させた水溶液中に触媒担持体を浸漬し引上げる方法などによって、比較的容易に粗面化表面にＴｉＯ2触媒をコーティングすることが可能である。 As a typical catalyst substance used for the purpose of air purification, deodorization, antibacterial, water purification, etc., there is TiO 2 (titanium oxide) which is a photocatalyst. In this case, it is possible to coat the TiO 2 catalyst on the roughened surface relatively easily by a method of immersing and lifting the catalyst support in an aqueous solution in which TiO 2 particles are dispersed.
市販のＳＵＳ４３０（１８Ｃｒ）フェライト系ステンレス鋼板、板厚０.２５ｍｍ、２Ｄ仕上げ材を用意した。この鋼板から切り出したサンプルについて、前処理として、濃度５質量％、液温６０℃のオルソケイ酸ナトリウム溶液に上記サンプルを浸漬し、電流密度０.５ｋＡ／ｍ2で１０秒間アノード電解する方法で電解脱脂を行った。 A commercially available SUS430 (18Cr) ferritic stainless steel plate having a thickness of 0.25 mm and a 2D finish was prepared. As a pretreatment, the sample cut out from this steel sheet was immersed in a sodium orthosilicate solution having a concentration of 5% by mass and a liquid temperature of 60 ° C., and electrolyzed by an anodic electrolysis at a current density of 0.5 kA / m 2 for 10 seconds. Degreasing was performed.
電解脱脂後のサンプルについて、塩化第二鉄水溶液中での交番電解による粗面化処理を種々の条件で施した。電解条件は表１中に示してある。比較材として電解粗面化処理を施していないもの（電解脱脂ままの表面肌のもの）も用意した。これらの電解粗面化処理材および電解処理を施していない比較材（以下、これらを「供試材」と呼ぶ）について、以下に示す方法で表面積増加率、および面粗さＳＰａを求めた。また、供試材を触媒担持体として用いて以下に示す方法でＰｔ触媒を担持させ、触媒性能を調べた。 About the sample after electrolytic degreasing, the roughening process by alternating electrolysis in ferric chloride aqueous solution was given on various conditions. The electrolysis conditions are shown in Table 1. As a comparative material, a material not subjected to electrolytic surface roughening (surface skin as electrolytically degreased) was also prepared. For these electrolytic surface-roughened materials and comparative materials not subjected to electrolytic treatment (hereinafter referred to as “test materials”), the surface area increase rate and the surface roughness SPa were determined by the methods described below. Further, using the test material as a catalyst support, a Pt catalyst was supported by the method described below, and the catalyst performance was examined.
図１に、本発明例の触媒担持体における電解粗面化表面のＳＥＭ写真を例示する。これは表１のＮｏ.１の例である。 In FIG. 1, the SEM photograph of the electrolytic roughening surface in the catalyst carrier of the example of this invention is illustrated. This is an example of No. 1 in Table 1.
（表面積増加率の測定）
全自動ガス吸着量測定装置（オートソーブ−１−Ｃ／ＶＰ／ＴＣＤ／ＭＳ（ユアサアイオニクス製）を用いて、クリプトンガス吸着法による定容法にて供試材の粗面化表面の表面積Ｓを測定した。これを測定領域の面積Ｓ0で除することにより完全平滑面に対する表面積増加率を求めた。表面積Ｓの測定は１２０℃真空下で６０分間脱気後に行った。結果を表１中に示す。
(Measurement of surface area increase rate)
Surface area S of the roughened surface of the test material by a constant volume method by krypton gas adsorption method using a fully automatic gas adsorption amount measuring device (Autosorb-1-C / VP / TCD / MS (manufactured by Yuasa Ionics)) By dividing this by the area S 0 of the measurement region, the surface area increase rate with respect to the completely smooth surface was determined, and the measurement of the surface area S was performed after deaeration for 60 minutes under vacuum at 120 ° C. The results are shown in Table 1. Shown in.
（面粗さＳＰａの測定）
走査型レーザー顕微鏡（オリンパス株式会社製；ＯＬＳ１２００）を用いて、供試材の粗面化表面における５１μｍ×５１μｍの表面領域について、分解能０.０１μｍにて面粗さＳＰａを測定した。具体的には、対物レンズ１００倍（深さ方向分解能：０.０１μｍ）、ズーム２.５倍の倍率に設定し、５１μｍ×５１μｍ視野の粗面化表面の画像を取り込んだ後、ピークノイズ除去および画像輝度平均化の画像処理を行うことによって三次元表面プロファイルを求め、そのデータに基づいて算出される面粗さＳＰａを求めた。結果を表１中に示す。
(Measurement of surface roughness SPa)
Using a scanning laser microscope (manufactured by Olympus Corporation; OLS1200), the surface roughness SPa was measured at a resolution of 0.01 μm for a 51 μm × 51 μm surface area on the roughened surface of the test material. Specifically, the objective lens is set to 100 × (depth resolution: 0.01 μm) and the zoom is set to 2.5 × magnification, and after removing the rough surface of the 51 μm × 51 μm field of view, peak noise is removed. Then, a three-dimensional surface profile was obtained by performing image processing for image luminance averaging, and a surface roughness SPa calculated based on the data was obtained. The results are shown in Table 1.
（Ｐｔ触媒の担持）
供試材の粗面化ステンレス鋼板を、濃度５質量％、液温６０℃のオルソケイ酸ナトリウム溶液に上記鋼板を浸漬し、電流密度０.５ｋＡ／ｍ2でアノード電解する方法で電解脱脂を行った。次いで、下地処理として、ＮｉＳＯ4・６Ｈ2Ｏ：４００ｇ／Ｌ、Ｎａ2ＳＯ4：１００ｇ／Ｌを含む液温５５℃、ｐＨ＝１.５のＮｉめっき浴を用い、電流密度０.５ｋＡ／ｍ2で１２秒間電気めっきを行う方法にて、粗面化表面上にＮｉ下地めっきを施した。その後、Ｐｔ濃度６ｇ／Ｌ、液温４５℃のＰｔめっき液を用い、電流密度０.１ｋＡ／ｍ2でＰｔめっきを施した。
(Support of Pt catalyst)
Electrolytic degreasing was performed by immersing the roughened stainless steel plate as a test material in a sodium orthosilicate solution having a concentration of 5% by mass and a liquid temperature of 60 ° C., followed by anodic electrolysis at a current density of 0.5 kA / m 2. It was. Next, as a base treatment, a Ni plating bath containing NiSO 4 .6H 2 O: 400 g / L, Na 2 SO 4 : 100 g / L and having a liquid temperature of 55 ° C. and pH = 1.5 is used, and the current density is 0.5 kA / Ni base plating was performed on the roughened surface by a method of electroplating at m 2 for 12 seconds. Thereafter, Pt plating was performed at a current density of 0.1 kA / m 2 using a Pt plating solution having a Pt concentration of 6 g / L and a solution temperature of 45 ° C.
図２に、本発明例におけるＰｔ触媒を担持させた状態の粗面化表面のＳＥＭ写真を例示する。これは図１に示したＮｏ.１の電解粗面化表面にＰｔ触媒を担持させたものである。他の発明例、比較例についても同様のＳＥＭ観察を行っている。観察の結果、本発明例のＰｔ触媒を担持させた状態の粗面化表面には、全域においてほぼ均一に、ピット壁にＰｔがコーティングされていることが確認された。 FIG. 2 illustrates an SEM photograph of the roughened surface in a state in which the Pt catalyst in the example of the present invention is supported. This is a Pt catalyst supported on the electrolytically roughened surface of No. 1 shown in FIG. Similar SEM observations are performed for other invention examples and comparative examples. As a result of the observation, it was confirmed that the roughened surface in which the Pt catalyst of the example of the present invention was supported was coated with Pt on the pit wall almost uniformly throughout the entire area.
（触媒性能）
上記のようにしてＰｔ触媒を担持させた触媒担持粗面化ステンレス鋼材を３００℃に加熱し、この状態で触媒を担持させた表面に２０ｍｏｌのシクロヘキサンを噴霧した後、揮発成分を捕捉し、冷却により液化させて回収し、液体クロマトグラフィーによりシクロヘキサンからベンゼンに変換された転化率を求めた。転化率が高いほど触媒性能に優れる。結果を表１に示す。
(Catalyst performance)
The catalyst-supported roughened stainless steel material supporting the Pt catalyst as described above is heated to 300 ° C., and 20 mol of cyclohexane is sprayed on the surface supporting the catalyst in this state, and then volatile components are captured and cooled. The amount of conversion from cyclohexane to benzene was determined by liquid chromatography. The higher the conversion rate, the better the catalyst performance. The results are shown in Table 1.
表１からわかるように、表面積増加率および面粗さＳＰａが適正範囲にある触媒担持体を用いた本発明例のものは、比較例のものに比べ、顕著に高い触媒性能が発揮された。 As can be seen from Table 1, the catalyst according to the present invention using the catalyst carrier having the surface area increase rate and the surface roughness SPa within the appropriate ranges exhibited significantly higher catalyst performance than that of the comparative example.
市販のＳＵＳ３０４（１８Ｃｒ−８Ｎｉ）オーステナイト系ステンレス鋼板、板厚０.２５ｍｍ、２Ｄ仕上げ材を用意した。この鋼板から切り出したサンプルについて、前処理として、濃度５質量％、液温６０℃のオルソケイ酸ナトリウム溶液に上記サンプルを浸漬し、電流密度０.５ｋＡ／ｍ2で１０秒間アノード電解する方法で電解脱脂を行った。 A commercially available SUS304 (18Cr-8Ni) austenitic stainless steel plate having a thickness of 0.25 mm and a 2D finish was prepared. As a pretreatment, the sample cut out from this steel sheet was immersed in a sodium orthosilicate solution having a concentration of 5% by mass and a liquid temperature of 60 ° C., and electrolyzed by an anodic electrolysis at a current density of 0.5 kA / m 2 for 10 seconds. Degreasing was performed.
電解脱脂後のサンプルについて、塩化第二鉄水溶液中での交番電解による粗面化処理を種々の条件で施した。電解条件は表２中に示してある。比較材として電解粗面化処理を施していないもの（電解脱脂ままの表面肌のもの）も用意した。これらの電解粗面化処理材および電解処理を施していない比較材（以下、これらを「供試材」と呼ぶ）について、実施例１と同様の方法で表面積増加率、および面粗さＳＰａを求めた。また、供試材を触媒担持体として用いて以下に示す方法でＴｉＯ2触媒を担持させ、触媒性能を調べた。 About the sample after electrolytic degreasing, the roughening process by alternating electrolysis in ferric chloride aqueous solution was given on various conditions. The electrolysis conditions are shown in Table 2. As a comparative material, a material not subjected to electrolytic surface roughening (surface skin as electrolytically degreased) was also prepared. About these electrolytic surface-roughened materials and comparative materials that have not been subjected to electrolytic treatment (hereinafter referred to as “test materials”), the surface area increase rate and the surface roughness SPa were determined in the same manner as in Example 1. Asked. Further, using the test material as a catalyst carrier, a TiO 2 catalyst was supported by the method described below, and the catalyst performance was examined.
（ＴｉＯ2触媒の担持）
供試材の粗面化ステンレス鋼板を、ディップコーター装置にセットし、ＴｉＯ2粒子を混合した溶液に浸せきした後、引上げ速度２ｍｍ／ｓｅｃで引上げた。その後、乾燥固化させた。
(Support of TiO 2 catalyst)
A roughened stainless steel plate as a test material was set in a dip coater, immersed in a solution mixed with TiO 2 particles, and then pulled up at a pulling rate of 2 mm / sec. Thereafter, it was dried and solidified.
図３に、本発明例におけるＴｉＯ2触媒を担持させた状態の粗面化表面のＳＥＭ写真を例示する。これは表２のＮｏ.１の例である。他の発明例、比較例についても同様のＳＥＭ観察を行っている。観察の結果、本発明例のＴｉＯ2触媒を担持させた状態の粗面化表面には、全域においてほぼ均一に、ピット壁にＴｉＯ2触媒がコーティングされていることが確認された。 FIG. 3 illustrates an SEM photograph of the roughened surface in a state where the TiO 2 catalyst in the example of the present invention is supported. This is an example of No. 1 in Table 2. Similar SEM observations are performed for other invention examples and comparative examples. As a result of the observation, it was confirmed that the pit wall was coated with the TiO 2 catalyst almost uniformly throughout the entire surface of the roughened surface in which the TiO 2 catalyst of the present invention was supported.
（触媒性能）
上記のようにしてＴｉＯ2触媒を担持させた触媒担持粗面化ステンレス鋼材を内容積約５０Ｌのチャンバーに入れて、ＮＯｘガスを濃度が約５００ｐｐｍになるまで注入した。そして、試験片に紫外線をブラックライトで３時間照射して、照射後のＮＯｘ濃度を測定し、ＮＯｘ分解率を算出した。分解率が高いほど触媒性能に優れる。結果を表２に示す。
(Catalyst performance)
The catalyst-supported roughened stainless steel material supporting the TiO 2 catalyst as described above was placed in a chamber having an internal volume of about 50 L, and NOx gas was injected until the concentration reached about 500 ppm. And the ultraviolet-ray was irradiated to the test piece with the black light for 3 hours, the NOx density | concentration after irradiation was measured, and the NOx decomposition rate was computed. The higher the decomposition rate, the better the catalyst performance. The results are shown in Table 2.
表２からわかるように、表面積増加率および面粗さＳＰａが適正範囲にある触媒担持体を用いた本発明例のものは、比較例のものに比べ、顕著に高い触媒性能が発揮された。 As can be seen from Table 2, the catalyst according to the present invention using the catalyst carrier having the surface area increasing rate and the surface roughness SPa within the appropriate ranges exhibited significantly higher catalyst performance than the comparative example.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008058802A JP2009213985A (en) | 2008-03-07 | 2008-03-07 | Catalytic carrier and stainless steel material for depositing catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008058802A JP2009213985A (en) | 2008-03-07 | 2008-03-07 | Catalytic carrier and stainless steel material for depositing catalyst |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2009213985A true JP2009213985A (en) | 2009-09-24 |
Family
ID=41186438
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008058802A Withdrawn JP2009213985A (en) | 2008-03-07 | 2008-03-07 | Catalytic carrier and stainless steel material for depositing catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2009213985A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017164192A1 (en) * | 2016-03-22 | 2017-09-28 | イムラ・ジャパン株式会社 | Photoelectrode, photoelectrochemical system for water decomposition, and method for producing photoelectrode |
-
2008
- 2008-03-07 JP JP2008058802A patent/JP2009213985A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017164192A1 (en) * | 2016-03-22 | 2017-09-28 | イムラ・ジャパン株式会社 | Photoelectrode, photoelectrochemical system for water decomposition, and method for producing photoelectrode |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5584923B2 (en) | Rutile type titanium dioxide photocatalyst | |
| JP4861168B2 (en) | Fuel cell separator based on austenitic stainless steel | |
| JP5568865B2 (en) | Gas decomposition element | |
| JP4554542B2 (en) | Electrode for electrolysis | |
| JP2009052069A (en) | Electrode for electrolysis | |
| Kaseem et al. | Advantage of an in-situ reactive incorporation over direct particles incorporation of V2O5 for a competitive plasma electrolysis coating | |
| JP2022051582A (en) | Titanium base material, method for manufacturing the same, electrode for water electrolysis and water electrolysis apparatus | |
| JP2007237090A (en) | Catalytic body using anodized aluminum film | |
| JP2011120998A (en) | Visible light responsive rutile type titanium dioxide photocatalyst | |
| JP5768195B1 (en) | Visible light responsive photocatalyst and method for producing the same | |
| JP2008126151A (en) | Catalytic body using anodic aluminum oxide film | |
| Girginov et al. | Characterization of porous anodic alumina with AC-incorporated silver | |
| Samadi et al. | Plasma electrolytic oxidation layers as alternative supports for metallic catalysts used in oxidation reaction for environmental application | |
| JP2009213985A (en) | Catalytic carrier and stainless steel material for depositing catalyst | |
| JP4986240B2 (en) | Catalytic reactor and catalytic reaction apparatus using the same | |
| JP4719919B2 (en) | Method for producing functional coating on aluminum-based material and aluminum-based material having the functional coating | |
| WO2019181681A1 (en) | Production method for structured catalyst and hydrogen production method using structured catalyst | |
| Brudzisz et al. | Pom-pom-like nanowire clusters prepared by potentiostatic oxidation of copper in NH4HCO3 solution | |
| WO2010008104A1 (en) | A formation ventilation gas purification coating structure using inorganic membrane, and method for manufacturing thereof | |
| EP1323471A1 (en) | Process for the preparation of articles in titanium coated with a thick layer of anatase, articles so obtainable and use thereof as photocatalysts | |
| JP3868513B2 (en) | Electrode for seawater electrolysis and method for producing the same | |
| JP2003522623A (en) | Manufacturing method of catalytic converter | |
| JP3989228B2 (en) | Method for producing alumina carrier with excellent heat resistance | |
| WO2018150823A1 (en) | Method for producing structured catalyst and method for producing hydrogen using structured catalyst | |
| JP2010158648A (en) | NOx DECOMPOSITION ELEMENT |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Application deemed to be withdrawn because no request for examination was validly filed |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20110510 |