JP4087621B2 - Catalyst for removing carbon monoxide in hydrogen gas - Google Patents
Catalyst for removing carbon monoxide in hydrogen gas Download PDFInfo
- Publication number
- JP4087621B2 JP4087621B2 JP2002059224A JP2002059224A JP4087621B2 JP 4087621 B2 JP4087621 B2 JP 4087621B2 JP 2002059224 A JP2002059224 A JP 2002059224A JP 2002059224 A JP2002059224 A JP 2002059224A JP 4087621 B2 JP4087621 B2 JP 4087621B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- platinum
- rhenium
- titania
- oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Classifications
-
- 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
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Description
【０００１】
【発明の属する技術分野】
本発明は、改質ガス等の水素リッチなガス中に含まれるＣＯを、水性ガスシフト反応によってＣＯ2に転化させて除去する際に用いるＣＯ除去用触媒に関するものである。
【０００２】
【従来の技術】
近年、固体高分子型燃料電池の改良が注目されている。固体高分子型燃料電池は、アノード側に水素（燃料）を供給し、カソード側に酸素または空気（酸化剤）を供給して、固体電解質膜（プロトン伝導膜）を介して反応させ、電流を得るものである。電極触媒としては、アノード、カソード共に白金黒、カーボンに白金あるいは白金合金を担持した触媒等が用いられているが、この電極触媒は水素（燃料）中にＣＯが含まれていると、少量でも被毒され電池性能の低下が著しいことが知られている。
【０００３】
水素ガス中のＣＯを除去する方法としては触媒の存在下、反応系内に酸素を導入し、ＣＯを選択的にＣＯ2に酸化し除去する方法（下記式(1)）、および反応系内に水（Ｈ2Ｏ）を添加し、触媒共存下水性ガスシフト反応を起こさせる方法（下記式(2)）が公知である。
［ＣＯ酸化反応］
ＣＯ＋1/2Ｏ2 → ＣＯ2 （1）
［水性ガスシフト反応］
ＣＯ＋Ｈ2Ｏ ⇔ ＣＯ2＋Ｈ2 （2）（ΔＨ＝−41 ｋJ/mol）
【０００４】
前者の方法では、反応系内の水素濃度が高い場合には、下記式(3)で示すように系内に導入した酸素が系内に多量に存在する水素と反応してしまうので、選択性の高い触媒が必要である。
Ｈ2＋1/2Ｏ2 → Ｈ2Ｏ （3）
【０００５】
一方、反応系内に水を添加する水性ガスシフト反応は、水素を製造する方法等として広く知られている（特開2000-302405号公報参照）。この方法の特徴としては、一般に２つの反応温度でのプロセスを組み合わせて行われることである。つまり、反応温度により高温シフト反応および低温シフト反応と呼ばれており、前記高温シフト反応は400℃前後で、また、前記低温シフト反応は250℃前後で行われる。水性ガスシフト反応は上記式（2）に示したように発熱反応であることから、低温で反応を行った方が平衡論的に水素生成に対しては有利であるが、反応速度が遅くなるという問題がある。そこで、高温では平衡的には不利であるが反応速度が速いことから、先ず高温で多量のＣＯをＣＯ2に転化し、次に低温で残ったＣＯをさらに低濃度になるように処理するという通常２段階プロセスで行われている。この高温シフト反応に用いられる触媒としては鉄-クロム-コバルト系の触媒が、低温シフト反応に用いられる触媒としては銅-亜鉛系の触媒が、従来より知られている（特公昭59-46883号公報、特開昭53-141191公報参照）。
【０００６】
また、最近では低温シフト反応用触媒としてジルコニア担体に白金、白金-レニウム等を担持させた触媒が、従来の銅-亜鉛系触媒よりも高活性を示すことが知られている（特許第3215680号公報参照）。しかし、前記触媒を用いて高温域（350℃前後）で水生ガスシフト反応を行った場合、下記式(4)に示すＣＯのメターネーション反応によりメタンを生成するという副反応を抑制することが不十分であり、水素生成効率を低下させるという問題がある。
［メタネーション反応］
ＣＯ+３Ｈ2 → ＣＨ4＋Ｈ2Ｏ (4)
この副反応は、水性ガスシフト反応によりＣＯを含まない水素を高収率で得ようとする場合、極めて好ましくない。
このようなことから、水生ガスシフト反応用触媒として、メタネーション反応を抑制し、かつ高活性なＣＯ除去用触媒が望まれていた。
【０００７】
【発明が解決しようとする課題】
本発明の課題は、上記水性ガスシフト反応において、高活性で、かつメタネーション反応を抑制し、水素ガス中のＣＯ濃度を効率的に低減させることができる触媒を提供することである。
【０００８】
【課題を解決するための手段】
本発明は、上記課題を解決するため、
チタニアまたはチタニアを含有する金属酸化物からなる担体に、白金および／または白金酸化物、並びに、レニウムおよび／またはレニウム酸化物を担持してなることを特徴とする水素ガス中の一酸化炭素除去用触媒を提供する。
【０００９】
【発明の実施の形態】
本発明の一酸化炭素除去用触媒について、以下に詳述する。
［担体］
本発明において用いられる担体は、チタニアまたはチタニアを添加した金属酸化物であり、いずれの場合も、通常、粒径２〜４mmφ程度の大きさの粒状、ペレット状等で多孔質のものが用いられる。
【００１０】
担体として、チタニアを添加した金属酸化物を用いる場合、前記金属酸化物としては、例えば、ジルコニア、アルミナ、シリカ、シリカ・アルミナ、ゼオライト、セリア等を挙げることができ、中でも、触媒調製が比較的容易であることなどの点から、ジルコニアまたはアルミナを用いることが好ましい。
【００１１】
上記金属酸化物にチタニアを添加する方法としては、粒状の金属酸化物に、例えば、しゅう酸チタンカリウム二水和物、塩化チタン、硫酸チタン等のチタン化合物の水溶液またはチタニアゾルを金属酸化物に滴下し、前記チタン化合物を前記粒状金属酸化物に含浸させたのち、乾燥し、次いで、通常、200〜700℃、好ましくは300〜600℃の温度で、10分〜３時間程度焼成することにより、チタニアを含有する金属酸化物を得ることができる。
【００１２】
こうして得られた粒状のチタニア含有金属酸化物に含有されるチタニアの量は、通常、0.1〜50.0重量％、好ましくは0.1〜20.0重量％、特に好ましくは0.1〜10.0重量％とする。チタニア含有量が少なすぎると、水性ガスシフト反応活性向上の効果が十分でなく、かつ、メタネーション反応の抑制が不十分となり、逆に多すぎると、前記効果の更なる向上が期待できないばかりか、経済性の利点に欠ける。
【００１３】
［触媒活性成分の担持］
上記担体に触媒活性成分である白金および／または白金酸化物、並びに、レニウムおよび／またはレニウム酸化物を担持させて、本発明のＣＯ除去用触媒を得ることができる。
上記触媒中の白金および／または白金酸化物、並びに、レニウムおよび／またはレニウム酸化物の担持量としては、触媒重量に対して、白金および／または白金酸化物が、通常、0.01〜20.0重量％、好ましくは0.01〜10.0重量％、特に好ましくは0.1〜5.0重量％であり、また、レニウムおよび／またはレニウム酸化物が、通常、0.01〜20.0重量％、好ましくは0.01〜10.0重量％、特に好ましくは0.1〜5.0重量％である。白金および／または白金酸化物、並びに、レニウムおよび／またはレニウム酸化物の含有量が少なすぎると、水性ガスシフト反応によって水素ガス中のＣＯをＣＯ2に転化させて除去する際の触媒活性を十分に得ることが困難であり、逆に多すぎても触媒活性の更なる向上が期待できないばかりか、貴金属を用いることから経済性の点で不利となる。
【００１４】
触媒として用いる、白金および／または白金酸化物と、レニウムおよび／またはレニウム酸化物との割合としては、金属原子重量比で、通常、Ｐｔ/Ｒｅ＝４/１〜１/４、好ましくは３/１〜１/３、特に好ましくは２/１〜１/２である。
【００１５】
上記担体に、白金および／または白金酸化物、並びに、レニウムおよび／またはレニウム酸化物を担持させる方法としては、特に制限はなく、公知の方法が採用される。
例えば、ジニトロジアンミン白金［Pt(NO2)2(NH3)2］の硝酸溶液または塩化白金酸六水和物等の水溶液を、上記担体に滴下・含浸したのち、乾燥させる。
次いで、例えば、過レニウム酸アンモニウム、過レニウム酸、酸化レニウム、塩化レニウム等のレニウム化合物の水溶液等を、同様に滴下・含浸したのち、乾燥させる。
なお、レニウム化合物溶液による処理を先に行い、その後に、白金化合物溶液による処理を行ってもよい。
次に、300〜700℃、好ましくは400〜600℃の温度で、30分〜２時間程度焼成することにより、担体に担持された金属としての白金および／または白金酸化物、並びに、金属としてのレニウムおよび／またはレニウム酸化物を存在せしめる。
【００１６】
［本発明触媒の特徴］
上記のようにして得られた本発明の触媒は、担体としてチタニアまたはチタニアを添加した金属酸化物を採用したことにより、白金およびレニウムの水性ガスシフト反応によるＣＯのＣＯ2への転化・除去の触媒活性を向上させ、かつ、メタネーション反応を抑制することができるものである。
【００１７】
【実施例】
実施例−１
ジルコニア粒状担体（第一稀元素化学工業(株)製：RSC-HP）100ｇを容器に入れ、しゅう酸チタンカリウム水溶液（濃度：40重量％）27 mLを滴下・含浸させ、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。更に、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、２重量％のチタニアを含むジルコニア粒状担体を調製した。
【００１８】
上記で得られた粒状担体の97ｇを容器に取り、ジニトロジアンミン白金硝酸溶液（濃度：7.4重量％、白金金属換算：2.0ｇ）27 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
乾燥後のものを、容器に入れ、過レニウム酸アンモニウム水溶液（濃度：3.7重量％、レニウム金属換算：1.0ｇ）27 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
【００１９】
続いて、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、ジルコニア粒状担体（チタニア２重量％含有）に白金（２重量％）およびレニウム（１重量％）が担持されたＣＯ除去用触媒100ｇを調製した。
【００２０】
比較例-１
ジルコニアにチタニアを担持させないこと以外は、実施例-１と同様にして、ジルコニア粒状担体に白金（２重量％）およびレニウム（１重量％）が担持されたＣＯ除去用触媒（比較用）100ｇを調製した。
【００２１】
実施例-２
アルミナ粒状担体（住友化学(株)製：KHA-24）100gを容器に入れ、しゅう酸チタンカリウム水溶液（濃度：40重量％）50 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。更に、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、４重量％のチタニアを含むアルミナ粒状担体を調製した。
【００２２】
上記で得られた粒状担体の97ｇを容器に取り、ジニトロジアンミン白金硝酸溶液（濃度：5.3重量％、白金金属換算：2.0ｇ）38 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
乾燥後のものを、容器に入れ、過レニウム酸アンモニウム水溶液（濃度：2.7重量％、レニウム金属換算：1.0ｇ）38 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
【００２３】
続いて、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、アルミナ粒状担体（チタニア４重量％含有）に白金（２重量％）およびレニウム（１重量％）が担持されたＣＯ除去用触媒100ｇを調製した。
【００２４】
比較例-２
アルミナにチタニアを担持させないこと以外は、実施例-２と同様にして、ジルコニア粒状担体に白金（２重量％）およびレニウム（１重量％）が担持されたＣＯ除去用触媒（比較用）100ｇを調製した。
【００２５】
参考例 - １
チタニア粒状担体（堺化学工業(株)製：CS-300S-24）97gを容器に入れ、ジニトロジアンミン白金硝酸溶液（濃度：10重量％、白金金属換算：2.0ｇ）20 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
乾燥後のものを、容器に入れ、過レニウム酸アンモニウム水溶液（濃度：5.0重量％、レニウム金属換算：1.0ｇ）20 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
【００２６】
続いて、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、チタニア粒状担体に白金（２重量％）およびレニウム（１重量％）が担持されたＣＯ除去用触媒100ｇを調製した。
【００２７】
比較例-３
チタニア粒状担体（堺化学工業(株)製：CS-300S-24）98gを容器に入れ、ジニトロジアンミン白金硝酸溶液（濃度：10重量％、白金金属換算：2.0ｇ）20 mLを滴下・含浸し、滴下終了後１時間放置した。その後、乾燥器を用い、空気中で110℃×２時間乾燥した。
続いて、焼成炉内において室温から500℃まで１時間で昇温し、500℃×１時間の焼成処理（空気中）を行ない、チタニア粒状担体に白金（２重量％）が担持されたＣＯ除去用触媒（比較用）100ｇを調製した。
【００２８】
上記実施例-１〜２、参考例 - １および比較例-１〜３の触媒組成を、表１にまとめて示す。
【００２９】
【表１】
［評価］
上記の実施例-１〜-２、参考例 - １および比較例-１〜-３の触媒について、ＣＯ除去性能等について評価した。
［評価方法］
容積15.0 mLの反応管に上記触媒を充填し、Ｈ2(20容量％)およびＮ2(80容量％)の混合ガスを流しながら、室温から300℃まで30分で昇温させた後、１時間同温度を保持して還元処理を行なった。
【００３１】
次に、混合ガスをＮ2ガスに切替え、加熱を止め100℃以下になるまで降温させた。温度が100℃以下に下がったら、Ｎ2ガスの供給を止めて、次に、Ｈ2(80容量％)、ＣＯ2(12容量％)およびＣＯ(８容量％)の混合ガスをＳＶ(空筒速度)が10,000(h-1)の条件で供給した。この混合ガスに、Ｈ2Ｏ（水蒸気）をＨ2Ｏ／ＣＯ＝4.2（容量比）となる条件を満足するように加え、触媒温度を200℃まで昇温し、200℃の温度で保持した定常状態で、反応管出口のＣＯ濃度（容量％)を、Ｈ2Ｏを除いた測定条件下で、非分散型赤外線法を測定原理としたガス分析計（(株)ベスト測器製：Bex-2201E）を用いて測定した。
【００３２】
同様にして、触媒温度が250℃、300℃および350℃の場合についても、測定を行った。
また、触媒温度が350℃の場合については、反応管出口のＣＨ4含有量（ppm）を、同様の手法および同一の測定機器を用いて測定した。
【００３３】
［測定結果および分析］
実施例、参考例および比較例の触媒についての上記測定結果を、図１〜図４に示す。
図１および図２から、チタニアを添加したジルコニアまたはアルミナ粒状担体を用いた触媒の場合の実施例-１および実施例-２について、チタニアを添加したことによるＣＯ濃度低減化効果が確認された。
図３から、レニウムを担持したチタニア粒状担体触媒の場合の参考例 - １について、白金とともにレニウムを併用したことによるＣＯ濃度低減化効果が確認された。
【００３４】
また、副反応としてメタネーション反応が生じていることを示すＣＨ４濃度について、図４に示した測定結果から、チタニアを添加したジルコニアまたはアルミナ粒状担体を用いた触媒の場合の実施例-１および実施例-２について、メタネーション反応が低く抑制されていることが確認された。レニウムを担持したチタニア粒状担体触媒の場合の参考例 - １の場合も、チタニアを添加したジルコニアまたはアルミナ粒状担体を用いた触媒の場合の実施例-１および実施例-２の場合よりも若干ＣＨ4濃度は高いが、チタニアを添加していないジルコニアまたはアルミナ粒状担体を用いた触媒の場合の比較例-１および比較例-２よりも、メタネーション反応が顕著に低く抑制されていることが分かる。
【００３５】
従って、本発明に係るＣＯ除去用触媒は、水生ガスシフト反応において、高温域（350℃）でメタネーション反応を抑制し、かつ、シフト反応の活性を高く維持できるものである。
【００３６】
【発明の効果】
本発明のＣＯ除去用触媒は、改質ガス等の水素リッチなガスに含まれるＣＯを水生ガスシフト反応によってＣＯ2に転化させて除去する際の触媒活性を高く維持することができる。更に、高温域でＣＯがＣＨ4に転化されるというメタネーション反応を抑制する効果をも奏するものである。この本発明のＣＯ除去用触媒は、例えば、燃料電池の燃料用の水素ガス製造用等に有用である。
【図面の簡単な説明】
【図１】 図１は、実施例-１および比較例-１で得た触媒の各触媒温度におけるＣＯ除去性能を示す図である。
【図２】 図２は、実施例-２および比較例-２で得た触媒の各触媒温度におけるＣＯ除去性能を示す図である。
【図３】 図３は、参考例 - １および比較例-３で得た触媒の各触媒温度におけるＣＯ除去性能を示す図である。
【図４】 図４は、実施例-１〜２、参考例 - １および比較例-１〜比較例-３で得た触媒の触媒温度350℃におけるメタネーション反応抑制性能を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a CO removal catalyst used when CO contained in a hydrogen-rich gas such as a reformed gas is removed by being converted to CO 2 by a water gas shift reaction.
[0002]
[Prior art]
In recent years, improvement of solid polymer fuel cells has attracted attention. A polymer electrolyte fuel cell supplies hydrogen (fuel) to the anode side, supplies oxygen or air (oxidant) to the cathode side, causes a reaction through a solid electrolyte membrane (proton conductive membrane), and generates a current. To get. As the electrode catalyst, platinum black is used for both the anode and the cathode, a catalyst in which platinum or a platinum alloy is supported on carbon, and this electrode catalyst can be used in a small amount when CO is contained in hydrogen (fuel). It is known that the battery performance is significantly deteriorated due to poisoning.
[0003]
As a method for removing CO in hydrogen gas, oxygen is introduced into the reaction system in the presence of a catalyst to selectively oxidize and remove CO to CO 2 (the following formula (1)), and in the reaction system. A method of adding water (H 2 O) to water to cause a water gas shift reaction in the presence of a catalyst (the following formula (2)) is known.
[CO oxidation reaction]
CO + 1/2 O 2 → CO 2 (1)
[Water gas shift reaction]
CO + H 2 O⇔CO 2 + H 2 (2) (ΔH = −41 kJ / mol)
[0004]
In the former method, when the hydrogen concentration in the reaction system is high, oxygen introduced into the system reacts with a large amount of hydrogen present in the system as shown in the following formula (3). High catalyst is required.
H 2 + 1 / 2O 2 → H 2 O (3)
[0005]
On the other hand, the water gas shift reaction in which water is added to the reaction system is widely known as a method for producing hydrogen (see JP 2000-302405 A). A feature of this method is that it is generally performed by combining processes at two reaction temperatures. That is, it is called a high temperature shift reaction and a low temperature shift reaction depending on the reaction temperature. The high temperature shift reaction is performed at about 400 ° C., and the low temperature shift reaction is performed at about 250 ° C. Since the water gas shift reaction is an exothermic reaction as shown in the above formula (2), it is better to perform the reaction at a low temperature in terms of equilibrium for hydrogen generation, but the reaction rate is slow. There's a problem. Therefore, it is disadvantageous in equilibrium at high temperatures, but the reaction rate is fast, so a large amount of CO is first converted to CO 2 at high temperatures, and then the remaining CO at low temperatures is processed to a lower concentration. Usually done in a two-step process. Conventionally, an iron-chromium-cobalt catalyst is known as a catalyst used in this high temperature shift reaction, and a copper-zinc catalyst is known as a catalyst used in a low temperature shift reaction (Japanese Patent Publication No. 59-46883). Gazette, JP-A-53-141191).
[0006]
Recently, a catalyst in which platinum, platinum-rhenium, etc. are supported on a zirconia support as a catalyst for low temperature shift reaction is known to exhibit higher activity than a conventional copper-zinc catalyst (Japanese Patent No. 3215680). See the official gazette). However, when the aquatic gas shift reaction is performed in the high temperature range (around 350 ° C) using the catalyst, it is insufficient to suppress the side reaction of generating methane by the CO methanation reaction represented by the following formula (4) There is a problem that the hydrogen generation efficiency is lowered.
[Methanation reaction]
CO + 3H 2 → CH 4 + H 2 O (4)
This side reaction is extremely undesirable when trying to obtain CO-free hydrogen in a high yield by the water gas shift reaction.
For this reason, a highly active CO removal catalyst that suppresses the methanation reaction and is highly active has been desired as an aquatic gas shift reaction catalyst.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a catalyst that is highly active in the water gas shift reaction, can suppress the methanation reaction, and can efficiently reduce the CO concentration in hydrogen gas.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention
For removing carbon monoxide in hydrogen gas, characterized in that platinum and / or platinum oxide and rhenium and / or rhenium oxide are supported on a carrier made of titania or a metal oxide containing titania. A catalyst is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The carbon monoxide removal catalyst of the present invention will be described in detail below.
[Carrier]
The carrier used in the present invention is titania or a metal oxide to which titania is added, and in any case, a porous material having a particle size of about 2 to 4 mmφ, a pellet shape, or the like is usually used. .
[0010]
When a metal oxide to which titania is added is used as the carrier, examples of the metal oxide include zirconia, alumina, silica, silica / alumina, zeolite, and ceria. From the standpoint of ease, it is preferable to use zirconia or alumina.
[0011]
As a method of adding titania to the metal oxide, for example, an aqueous solution of a titanium compound such as titanium potassium oxalate dihydrate, titanium chloride, titanium sulfate, or titania sol is dropped onto the metal oxide. Then, after impregnating the titanium compound with the granular metal oxide, drying, and then firing usually at a temperature of 200 to 700 ° C., preferably 300 to 600 ° C. for about 10 minutes to 3 hours, A metal oxide containing titania can be obtained.
[0012]
The amount of titania contained in the granular titania-containing metal oxide thus obtained is usually 0.1 to 50.0% by weight, preferably 0.1 to 20.0% by weight, particularly preferably 0.1 to 10.0% by weight. If the titania content is too small, the effect of improving the water gas shift reaction activity is not sufficient, and the suppression of the methanation reaction is insufficient. Lack of economic advantages.
[0013]
[Supporting catalytically active components]
The catalyst for removing CO of the present invention can be obtained by supporting platinum and / or platinum oxide and rhenium and / or rhenium oxide as catalytically active components on the carrier.
The supported amount of platinum and / or platinum oxide and rhenium and / or rhenium oxide in the catalyst is usually 0.01 to 20.0% by weight of platinum and / or platinum oxide with respect to the catalyst weight. Preferably 0.01 to 10.0% by weight, particularly preferably 0.1 to 5.0% by weight, and rhenium and / or rhenium oxide is usually 0.01 to 20.0% by weight, preferably 0.01 to 10.0% by weight, particularly preferably 0.1%. -5.0 wt%. If the content of platinum and / or platinum oxide and rhenium and / or rhenium oxide is too small, sufficient catalytic activity is obtained when CO in hydrogen gas is converted to CO 2 and removed by water gas shift reaction. It is difficult to obtain, and conversely, if it is too much, not only a further improvement in the catalyst activity can not be expected, but the use of precious metals is disadvantageous in terms of economy.
[0014]
The ratio of platinum and / or platinum oxide and rhenium and / or rhenium oxide used as a catalyst is usually Pt / Re = 4/1 to 1/4, preferably 3 / 1 to 1/3, particularly preferably 2/1 to 1/2.
[0015]
The method for supporting platinum and / or platinum oxide and rhenium and / or rhenium oxide on the carrier is not particularly limited, and a known method is employed.
For example, a nitric acid solution of dinitrodiammine platinum [Pt (NO 2 ) 2 (NH 3 ) 2 ] or an aqueous solution such as chloroplatinic acid hexahydrate is added dropwise to the carrier and then dried.
Next, for example, an aqueous solution of a rhenium compound such as ammonium perrhenate, perrhenic acid, rhenium oxide, or rhenium chloride is dropped and impregnated in the same manner, and then dried.
Note that the treatment with the rhenium compound solution may be performed first, and then the treatment with the platinum compound solution may be performed.
Next, it is calcined at a temperature of 300 to 700 ° C., preferably 400 to 600 ° C. for about 30 minutes to 2 hours, so that platinum and / or platinum oxide as a metal supported on the carrier and Rhenium and / or rhenium oxide is present.
[0016]
[Characteristics of the catalyst of the present invention]
The catalyst of the present invention obtained as described above employs titania or a metal oxide to which titania is added as a carrier, and thereby converts and removes CO to CO 2 by water gas shift reaction of platinum and rhenium. The activity can be improved and the methanation reaction can be suppressed.
[0017]
【Example】
Example-1
Place 100 g of zirconia granular carrier (Daiichi Rare Element Chemical Co., Ltd .: RSC-HP) in a container, drop and impregnate 27 mL of aqueous potassium potassium oxalate solution (concentration: 40% by weight), 1 hour after completion of dropping I left it alone. Then, it dried at 110 degreeC * 2 hours in the air using the dryer. Furthermore, the temperature was raised from room temperature to 500 ° C. in a baking furnace in 1 hour, and a baking treatment (in air) was performed at 500 ° C. for 1 hour to prepare a zirconia granular carrier containing 2% by weight of titania.
[0018]
97 g of the granular carrier obtained above was put in a container, and 27 mL of dinitrodiammine platinum nitric acid solution (concentration: 7.4 wt%, platinum metal conversion: 2.0 g) was dropped and impregnated, and allowed to stand for 1 hour after completion of dropping. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
The dried product was placed in a container and dropped and impregnated with 27 mL of an aqueous ammonium perrhenate solution (concentration: 3.7% by weight, rhenium metal equivalent: 1.0 g), and allowed to stand for 1 hour after completion of the addition. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
[0019]
Subsequently, the temperature was raised from room temperature to 500 ° C. in a baking furnace in one hour, and a baking treatment (in air) of 500 ° C. × 1 hour was performed. Platinum (2% by weight) was added to a zirconia granular carrier (containing 2% by weight of titania). ) And rhenium (1 wt%) supported 100 g of a CO removal catalyst was prepared.
[0020]
Comparative Example-1
Except for not allowing titania to be supported on zirconia, 100 g of a CO removal catalyst (for comparison) in which platinum (2 wt%) and rhenium (1 wt%) were supported on a zirconia granular support in the same manner as in Example-1. Prepared.
[0021]
Example-2
100 g of alumina granular carrier (Sumitomo Chemical Co., Ltd .: KHA-24) was put in a container, 50 mL of titanium potassium oxalate aqueous solution (concentration: 40% by weight) was dropped and impregnated, and allowed to stand for 1 hour after completion of dropping. Then, it dried at 110 degreeC * 2 hours in the air using the dryer. Furthermore, the temperature was raised from room temperature to 500 ° C. in a baking furnace in 1 hour, and a baking treatment (in air) was performed at 500 ° C. for 1 hour to prepare an alumina granular carrier containing 4% by weight of titania.
[0022]
97 g of the granular carrier obtained above was put in a container, 38 mL of dinitrodiammine platinum nitric acid solution (concentration: 5.3 wt%, platinum metal conversion: 2.0 g) was dropped and impregnated, and left for 1 hour after the end of dropping. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
The dried product was placed in a container, and 38 mL of an aqueous ammonium perrhenate solution (concentration: 2.7% by weight, rhenium metal equivalent: 1.0 g) was added dropwise and impregnated, and left for 1 hour after completion of the addition. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
[0023]
Subsequently, the temperature was raised from room temperature to 500 ° C. in a firing furnace in 1 hour, and the firing treatment (in air) was performed at 500 ° C. for 1 hour, and platinum (2% by weight) was added to an alumina granular carrier (containing 4% by weight of titania). ) And rhenium (1 wt%) supported 100 g of a CO removal catalyst was prepared.
[0024]
Comparative Example-2
Except that titania is not supported on alumina, 100 g of a CO removal catalyst (for comparison) in which platinum (2% by weight) and rhenium (1% by weight) are supported on a zirconia granular carrier in the same manner as in Example-2. Prepared.
[0025]
Reference example - 1
Put 97g of titania granular carrier (Sakai Chemical Industry Co., Ltd .: CS-300S-24) in a container and drop and impregnate 20mL of dinitrodiammine platinum nitrate solution (concentration: 10wt%, platinum metal equivalent: 2.0g). The mixture was allowed to stand for 1 hour after completion of the dropping. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
The dried product was placed in a container, and 20 mL of an aqueous ammonium perrhenate solution (concentration: 5.0% by weight, rhenium metal equivalent: 1.0 g) was added dropwise and impregnated. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
[0026]
Subsequently, the temperature was raised from room temperature to 500 ° C. in a baking furnace in 1 hour, and a baking treatment (in air) was performed at 500 ° C. for 1 hour, and platinum (2% by weight) and rhenium (1% by weight) were formed on the titania granular carrier. 100 g of a CO removal catalyst on which was supported).
[0027]
Comparative Example-3
98 g of titania granular carrier (Sakai Chemical Industry Co., Ltd .: CS-300S-24) is put in a container, and 20 mL of dinitrodiammine platinum nitrate solution (concentration: 10% by weight, platinum metal equivalent: 2.0 g) is dropped and impregnated. The mixture was allowed to stand for 1 hour after completion of the dropping. Then, it dried at 110 degreeC * 2 hours in the air using the dryer.
Subsequently, the temperature is raised from room temperature to 500 ° C. in a baking furnace in one hour, and a baking treatment (in air) is performed at 500 ° C. for one hour, and CO removal in which platinum (2 wt%) is supported on a titania granular carrier is performed. 100 g of a catalyst for comparison (for comparison) was prepared.
[0028]
The catalyst compositions of Examples 1-2 and Reference Example - 1 and Comparative Examples-1 to 1-3 are summarized in Table 1.
[0029]
[Table 1]
[Evaluation]
With respect to the catalysts of Examples- 1 and -2 , Reference Example - 1 and Comparative Examples- 1 to -3, the CO removal performance and the like were evaluated.
[Evaluation methods]
The above catalyst was filled in a 15.0 mL reaction tube, and the temperature was raised from room temperature to 300 ° C. in 30 minutes while flowing a mixed gas of H 2 (20% by volume) and N 2 (80% by volume). The reduction treatment was carried out while maintaining the same temperature for a time.
[0031]
Next, the mixed gas was switched to N 2 gas, the heating was stopped, and the temperature was lowered to 100 ° C. or lower. When the temperature falls below 100 ° C., the supply of N 2 gas is stopped, and then a mixed gas of H 2 (80% by volume), CO 2 (12% by volume) and CO (8% by volume) is supplied to SV (empty). The cylinder speed was supplied under the condition of 10,000 (h -1 ). To this mixed gas, H 2 O (water vapor) was added so as to satisfy the condition of H 2 O / CO = 4.2 (volume ratio), the catalyst temperature was raised to 200 ° C., and the temperature was maintained at 200 ° C. In a steady state, the CO concentration (volume%) at the outlet of the reaction tube was measured under a measurement condition excluding H 2 O, and a gas analyzer based on the non-dispersive infrared method (manufactured by Best Instrument Co., Ltd .: Bex) -2201E).
[0032]
In the same manner, the measurement was performed for catalyst temperatures of 250 ° C., 300 ° C., and 350 ° C.
When the catalyst temperature was 350 ° C., the CH 4 content (ppm) at the outlet of the reaction tube was measured using the same method and the same measuring equipment.
[0033]
[Measurement results and analysis]
The said measurement result about the catalyst of an Example , a reference example, and a comparative example is shown in FIGS.
From FIGS. 1 and 2, the effects of reducing CO concentration by adding titania were confirmed for Example-1 and Example-2 in the case of a catalyst using zirconia or alumina granular support to which titania was added.
From FIG. 3, it was confirmed that in Reference Example - 1 in the case of a titania granular support catalyst supporting rhenium, the effect of reducing CO concentration by using rhenium together with platinum was confirmed.
[0034]
Further, with respect to the CH 4 concentration indicating that a methanation reaction occurs as a side reaction, from the measurement results shown in FIG. 4, Example-1 in the case of a catalyst using titania-added zirconia or an alumina granular carrier and Regarding Example-2, it was confirmed that the methanation reaction was suppressed to a low level. Reference Example for titania particulate support catalyst carrying rhenium -
[0035]
Therefore, the catalyst for removing CO according to the present invention can suppress the methanation reaction at a high temperature (350 ° C.) and maintain the activity of the shift reaction at a high level in the aquatic gas shift reaction.
[0036]
【The invention's effect】
The catalyst for removing CO of the present invention can maintain high catalytic activity when CO contained in hydrogen-rich gas such as reformed gas is converted to CO 2 by aquatic gas shift reaction and removed. Furthermore, the effect of suppressing the methanation reaction in which CO is converted to CH 4 at high temperatures is also achieved. This CO removal catalyst of the present invention is useful, for example, for producing hydrogen gas for fuel of a fuel cell.
[Brief description of the drawings]
FIG. 1 is a graph showing CO removal performance at various catalyst temperatures of the catalysts obtained in Example-1 and Comparative Example-1.
FIG. 2 is a graph showing CO removal performance at various catalyst temperatures of the catalysts obtained in Example-2 and Comparative Example-2.
FIG. 3 is a graph showing CO removal performance at various catalyst temperatures of the catalysts obtained in Reference Example - 1 and Comparative Example-3.
FIG. 4 is a graph showing methanation reaction suppression performance of the catalysts obtained in Examples- 1 and 2, Reference Example - 1 and Comparative Examples- 1 to Comparative Example-3 at a catalyst temperature of 350 ° C.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002059224A JP4087621B2 (en) | 2002-03-05 | 2002-03-05 | Catalyst for removing carbon monoxide in hydrogen gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002059224A JP4087621B2 (en) | 2002-03-05 | 2002-03-05 | Catalyst for removing carbon monoxide in hydrogen gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003251181A JP2003251181A (en) | 2003-09-09 |
| JP4087621B2 true JP4087621B2 (en) | 2008-05-21 |
Family
ID=28668970
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002059224A Expired - Fee Related JP4087621B2 (en) | 2002-03-05 | 2002-03-05 | Catalyst for removing carbon monoxide in hydrogen gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4087621B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6932848B2 (en) * | 2003-03-28 | 2005-08-23 | Utc Fuel Cells, Llc | High performance fuel processing system for fuel cell power plant |
| US20050119119A1 (en) * | 2003-12-02 | 2005-06-02 | Rogers David B. | Water gas shift catalyst on a lanthanum-doped anatase titanium dioxide support for fuel cells application |
| JP4569408B2 (en) * | 2005-07-25 | 2010-10-27 | 堺化学工業株式会社 | Water gas shift reaction catalyst and method for removing carbon monoxide gas from hydrogen gas using the same |
| US7357911B2 (en) * | 2005-12-16 | 2008-04-15 | Basf Catalysts Llc | Process conditions for Pt-Re bimetallic water gas shift catalysts |
| KR100862272B1 (en) * | 2006-08-09 | 2008-10-09 | 주식회사 코캣 | Catalyst for Removal of Carbon Monoxide and Preparation Method Thereof |
| US8119558B2 (en) | 2008-03-14 | 2012-02-21 | Süd-Chemie Inc. | Ultra high temperature shift catalyst with low methanation |
-
2002
- 2002-03-05 JP JP2002059224A patent/JP4087621B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003251181A (en) | 2003-09-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2000054879A1 (en) | Catalyst for water gas shift reaction, method for removing carbon monoxide in hydrogen gas and electric power-generating system of fuel cell | |
| US7354882B2 (en) | Carbon monoxide removing catalyst and production process for the same as well as carbon monoxide removing apparatus | |
| JP2007252988A (en) | Catalyst for carbon monoxide methanation and methanation method of carbon monoxide using the catalyst | |
| KR101109394B1 (en) | Catalyst for Removal of Carbon Monoxide from Hydrogen Gas | |
| JP4087621B2 (en) | Catalyst for removing carbon monoxide in hydrogen gas | |
| KR20130089348A (en) | Incorporation of reducing metal oxide onto silica or zirconia for improving the selective reduction of no and durability thereof | |
| JP2003144925A (en) | Method for manufacturing catalyst for shift reaction of carbon monoxide | |
| JP4824332B2 (en) | Carbon monoxide removal catalyst | |
| CN108367276A (en) | The steam reforming catalyst of hydrocarbon | |
| JP5105709B2 (en) | Water gas shift reaction catalyst | |
| JP2008161742A (en) | Catalyst for removing carbon monoxide in hydrogen gas | |
| JP4250971B2 (en) | Inorganic material and shift catalyst using the same | |
| JP4120862B2 (en) | Catalyst for CO shift reaction | |
| JP2001149781A (en) | Catalyst for selectively oxidizing gaseous carbon monoxide in hydrogen-rich gas and method for removing carbon monoxide using the same | |
| JP4304385B2 (en) | Catalyst for oxidation removal of methane in exhaust gas and method for oxidation removal of methane in exhaust gas | |
| JP2000246102A (en) | Production of catalyst | |
| JP3939998B2 (en) | Shift catalyst and method for producing the same | |
| JP2001252564A (en) | Co selective oxidation catalyst and method for cutting co concentration in methanol-modified gas | |
| JP3975803B2 (en) | Method for producing CO selective oxidation catalyst | |
| JP2004097859A (en) | Catalyst and method for eliminating carbon monoxide | |
| JP3953302B2 (en) | Shift catalyst | |
| WO2018070381A1 (en) | Iron-based composite oxide catalyst for exhaust gas purification and method for producing same | |
| JP2007029811A (en) | Shift reaction catalyst for water gas, and method for removing carbon monoxide gas in hydrogen gas by using the same | |
| JP2006142239A (en) | Co-removing catalyst and its manufacturing method | |
| JP2006043608A (en) | Shift catalyst and method for producing it |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050210 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20071107 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20071113 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080111 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080219 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080221 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110228 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4087621 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120229 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120229 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130228 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140228 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |