JPH0113900B2 - - Google Patents
Info
- Publication number
- JPH0113900B2 JPH0113900B2 JP53101367A JP10136778A JPH0113900B2 JP H0113900 B2 JPH0113900 B2 JP H0113900B2 JP 53101367 A JP53101367 A JP 53101367A JP 10136778 A JP10136778 A JP 10136778A JP H0113900 B2 JPH0113900 B2 JP H0113900B2
- Authority
- JP
- Japan
- Prior art keywords
- iridium
- carrier
- catalyst
- salt
- metal component
- 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
Links
- 239000003054 catalyst Substances 0.000 claims description 76
- 229910052751 metal Inorganic materials 0.000 claims description 54
- 239000002184 metal Substances 0.000 claims description 54
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims description 49
- 239000000243 solution Substances 0.000 claims description 45
- 229910052741 iridium Inorganic materials 0.000 claims description 41
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 41
- 230000003197 catalytic effect Effects 0.000 claims description 27
- 238000000354 decomposition reaction Methods 0.000 claims description 26
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 24
- 150000002429 hydrazines Chemical class 0.000 claims description 24
- 239000011148 porous material Substances 0.000 claims description 22
- 150000003839 salts Chemical class 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 14
- 239000001257 hydrogen Substances 0.000 claims description 12
- 229910052739 hydrogen Inorganic materials 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 11
- 229910052707 ruthenium Inorganic materials 0.000 claims description 11
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 10
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 238000007598 dipping method Methods 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 8
- 239000002245 particle Substances 0.000 claims description 8
- 239000012266 salt solution Substances 0.000 claims description 8
- 150000002739 metals Chemical class 0.000 claims description 7
- 150000002503 iridium Chemical class 0.000 claims description 6
- 238000002791 soaking Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 4
- 238000002156 mixing Methods 0.000 claims 1
- 238000007654 immersion Methods 0.000 description 12
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 9
- 229910021638 Iridium(III) chloride Inorganic materials 0.000 description 8
- DANYXEHCMQHDNX-UHFFFAOYSA-K trichloroiridium Chemical compound Cl[Ir](Cl)Cl DANYXEHCMQHDNX-UHFFFAOYSA-K 0.000 description 8
- 125000004429 atom Chemical group 0.000 description 6
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 5
- 235000011114 ammonium hydroxide Nutrition 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002923 metal particle Substances 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- 230000009467 reduction Effects 0.000 description 5
- 238000011282 treatment Methods 0.000 description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910021645 metal ion Inorganic materials 0.000 description 4
- 230000002269 spontaneous effect Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000032683 aging Effects 0.000 description 3
- 235000019270 ammonium chloride Nutrition 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 3
- 230000008021 deposition Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical group N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 235000015842 Hesperis Nutrition 0.000 description 2
- 235000012633 Iberis amara Nutrition 0.000 description 2
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 230000001476 alcoholic effect Effects 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- -1 hexachloroiridate Chemical compound 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- YOLNUNVVUJULQZ-UHFFFAOYSA-J iridium;tetrachloride Chemical compound [Cl-].[Cl-].[Cl-].[Cl-].[Ir] YOLNUNVVUJULQZ-UHFFFAOYSA-J 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- RHUYHJGZWVXEHW-UHFFFAOYSA-N 1,1-Dimethyhydrazine Chemical compound CN(C)N RHUYHJGZWVXEHW-UHFFFAOYSA-N 0.000 description 1
- DJOYTAUERRJRAT-UHFFFAOYSA-N 2-(n-methyl-4-nitroanilino)acetonitrile Chemical compound N#CCN(C)C1=CC=C([N+]([O-])=O)C=C1 DJOYTAUERRJRAT-UHFFFAOYSA-N 0.000 description 1
- NGNBDVOYPDDBFK-UHFFFAOYSA-N 2-[2,4-di(pentan-2-yl)phenoxy]acetyl chloride Chemical class CCCC(C)C1=CC=C(OCC(Cl)=O)C(C(C)CCC)=C1 NGNBDVOYPDDBFK-UHFFFAOYSA-N 0.000 description 1
- 229910052580 B4C Inorganic materials 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910021639 Iridium tetrachloride Inorganic materials 0.000 description 1
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 229910026551 ZrC Inorganic materials 0.000 description 1
- OTCHGXYCWNXDOA-UHFFFAOYSA-N [C].[Zr] Chemical compound [C].[Zr] OTCHGXYCWNXDOA-UHFFFAOYSA-N 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000010420 art technique Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910001593 boehmite Inorganic materials 0.000 description 1
- INAHAJYZKVIDIZ-UHFFFAOYSA-N boron carbide Chemical compound B12B3B4C32B41 INAHAJYZKVIDIZ-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000007809 chemical reaction catalyst Substances 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- RCJVRSBWZCNNQT-UHFFFAOYSA-N dichloridooxygen Chemical compound ClOCl RCJVRSBWZCNNQT-UHFFFAOYSA-N 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 239000012456 homogeneous solution Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 description 1
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- HDZGCSFEDULWCS-UHFFFAOYSA-N monomethylhydrazine Chemical compound CNN HDZGCSFEDULWCS-UHFFFAOYSA-N 0.000 description 1
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000003380 propellant Substances 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 150000003303 ruthenium Chemical class 0.000 description 1
- YBCAZPLXEGKKFM-UHFFFAOYSA-K ruthenium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Ru+3] YBCAZPLXEGKKFM-UHFFFAOYSA-K 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- CALMYRPSSNRCFD-UHFFFAOYSA-J tetrachloroiridium Chemical compound Cl[Ir](Cl)(Cl)Cl CALMYRPSSNRCFD-UHFFFAOYSA-J 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
- ZVWKZXLXHLZXLS-UHFFFAOYSA-N zirconium nitride Chemical compound [Zr]#N ZVWKZXLXHLZXLS-UHFFFAOYSA-N 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Classifications
-
- B01J35/60—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
- B01J23/40—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals of the platinum group metals
- B01J23/46—Ruthenium, rhodium, osmium or iridium
- B01J23/468—Iridium
-
- B01J35/615—
-
- B01J35/633—
-
- 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
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Description
本発明はヒドラジン分解用触媒、更に詳しくは
ヒドラジンおよびアルキル置換ヒドラジンの分解
を有利に行わせるための新規触媒およびその製法
に関する。
ヒドラジンおよび低級アルキル置換ヒドラジン
（以下、合わせてヒドラジン類という。）はロケツ
トおよび他の推力装置に用いる単一推進燃料とし
て有用である。ヒドラジン類は分解に際し熱およ
びエネルギーの発生を伴い、ロケツト、宇宙船な
どの姿勢制御用ジエツトの作動に用いる他に、タ
ービン運転用のガスの発生に用いることができ
る。これまでヒドラジン類の分解用として提供さ
れた触媒は重大な欠点を有していた。たとえば白
金族金属の触媒が知られている（米国特許第
3081595号および第3086945号など参照）。しかし
これら触媒は推力装置およびガス発生装置に使用
する場合の全ての厳しい要件には適合しない。こ
れらの要件には比較的低温（たとえば液体ヒドラ
ジンが約1.7℃（約3.5〓）で触媒温度が約−17.8
℃（約０〓）でヒドラジンの分解を開始せしめる
性能が含まれる。更に、低温でのスタートから点
火遅れが100ミリ秒以下であり、スタート時に感
知しうる程の過圧もなく１分間に少くとも10回燃
焼させる性能を有していなければならない。加え
て、ヒドラジンの分解ではしばしば生じる1093.3
℃（200〓）程度の高温に耐えなければならない。
ロケツトに応用した場合に受ける取扱いに耐える
適当な物理的強度を有する必要があり、宇宙空間
に約１年間置かれた後にも触媒作用を発揮しなけ
ればならない。これらの本質的な要件を従来の先
行技術で製造されたヒドラジン分解用触媒は満し
ていない。
本発明の重要な目的はヒドラジン類の分解にお
けるこれらの要件を満足する触媒を提供すること
にある。ヒドラジンは排気口のない貯蔵槽で長期
間貯蔵できる比較的安定な化学薬品であるのでロ
ケツトエンジンで採用される高流速で自発的に点
火させるには活性の非常に高い触媒が必要とされ
る。加えて、ヒドラジンの分解では温度は普通の
触媒反応に比べ高温に達するから、何度も再点火
する性能を持たせようとするならば触媒は非常に
安定でなければならない。本発明の新規触媒はこ
れらの要件を満足し、かつヒドラジン類分解用の
自発触媒としての有効期間が長い。ここで自発触
媒とはヒドラジン類がロケツトエンジンおよびガ
ス発生室中で触媒に対し高速で噴射された時、分
解を開始させて分解を持続させる触媒をいう。さ
らに本発明の他の利点は以下に述べる説明から明
らかになる。
発明者らは、特別の方法で臨界的な高濃度から
特別な形状の支持体に付着させた特別な型のイリ
ジウム金属触媒が独特の性質の組合せを有し、ヒ
ドラジン類の分解用触媒として要求される高い活
性および良好な安定性という前述の厳しい要件を
満足することを見い出した。新規触媒は必須の構
成要素として次の条件を満す担体を有している。
その条件とは、担体が次式：
SS195（CP＋0.013＋0.736VP）
〔式中、SSは比表面積（m2／ｇ）、CPは約25℃で
の比熱容量（cal／ｇ・deg）、VPは孔容積（cm3／
ｇ）を表わす。〕
で示される関係を満す比表面積SSを有することで
ある。ここでVPは0.1より小さくてはならない。
かかる式は実験的または理論的に導かれたもの
で、代表的には実験によつて得られるものであ
る。この種の担体にはヒドラジン類と触媒金属の
触媒を妨げる程度に孔が塞がれることなく新規触
媒に必須である触媒金属の必要量を保持する孔容
積が存在するばかりでなく、分解開始時に液体ヒ
ドラジンで孔を満した場合、多孔質触媒を湿潤し
て生じる熱により少くとも20℃の望ましい平均温
度上昇が起る。この種の担体を用いた新規触媒を
使用すれば、不利な開始条件下でもヒドラジン類
のなめらかな自発的分解が起る。特に好ましく
は、該担体は約100〜300m2／ｇの比表面積、約
0.3〜0.5cm3／ｇの孔容積および約44.5〜133.4N（約
10〜30bs）の破砕強さを有するアルミナ担体で
ある。
イリジウムは新規触媒の触媒金属として単独で
使用した場合のみならず、ルテニウムと特に効果
的に組み合わせて使用した場合にも顕著な有利性
を有する。この組合せにおいては、ルテニウムと
の混合物中にイリジウムが約30〜80原子％の割合
となるように用いるのが望ましい。触媒がヒドラ
ジン類の自発的分解に必要な所望の高活性を有す
るには、イリジウムまたはイリジウムおよびルテ
ニウムの混合物が触媒の最終製品中に約20〜40重
量％の割合で存在することが必要である。新規触
媒に多数回の連続的なスタートを失敗なく起すこ
とができる安定性を持たせるには触媒金属を担体
表面に適当に分布させなければならない。触媒金
属各粒子がヒドラジン類の分解で発生する高温で
一緒に溶融または焼結することがない様に金属は
相互に充分距離を保つた独立した粒子として付着
させなければならない。最も好ましくは、直径約
10〜100Åの金属粒子が相互に平均約20〜200Å離
れて担体表面上に均一に分散される。金属粒子直
径が約20Åであり、相互間距離が約50Åである場
合が最も有利である。ここで相互間距離は担体表
面にそつて測つた理想化された距離を意味し、孔
壁内部を通つた最短距離ではないものとする。
触媒金属を必要通り分布させることは従来の触
媒製造法では不可能である。従来技術を用いた場
合、触媒金属により担体は多少とも均一連続に被
覆されるが、これを避けるには特別の方法が必要
である。所望量の触媒金属またはその混合物を選
択された担体の孔中に深く拡散し、内部から表面
に向つて金属の濃度を次第に濃くして担体の表面
部分、特に担体粒子の約0.5mmの周辺表皮部分で
は特に高濃度になる様に製造する必要がある。担
体の形状は球または円筒状の小片が有利であるが
他の形状も用いられる。担体は表皮部分が触媒金
属で過剰に付着され、分解すべきヒドラジン類の
浸透を過度に妨げる様になつてはならない。ヒド
ラジンの分解の大部分は担体の表面部分、すなわ
ち0.1〜0.5mmの厚さの所で起つていると推測され
る。浸透した金属（または混合物）は恐らく次の
２つの効果を有している。すなわち(1)担体全体に
熱を分散させ、絶縁支持への急激な熱衝撃を緩和
する。(2)外表面部に高濃度に付着された触媒金属
が連続燃焼により徐々に腐食された後、反応触媒
として働く。
本発明の新規触媒の製法の中で特に有利な方法
は、担体を、ルテニウム塩を含有しまたは含有し
ないイリジウム塩の希薄溶液に繰り返し浸漬する
方法である。浸漬毎に金属イオンが担体表面に吸
着される。濃厚溶液を用いれば、金属イオンが高
濃度で密集し、分解および還元して形成された金
属粒子は大きくなりすぎあるいは相互に接近しす
ぎる。希薄溶液に浸漬した後、単に乾燥するだけ
では種結晶が残り次の付着が同じ部位に生じて濃
厚溶液を使用した場合と同様の問題が生じる。そ
こで、次に希薄溶液に浸漬する前に金属イオンを
変換する処理を行うことが必要となる。更に、こ
の処理は次の浸漬中に前回付着した塩が再溶解す
るのを防ぎ、担体表面上のすでに被覆されていな
い部位への付着を促進するような効果を有してい
なければならない。多数回浸漬処理において、最
良の触媒性能を得るには、初期の数回の浸漬の間
に脱気して担体のガス抜きを行い、塩溶液の浸透
をより良く行わせるのが有利である。
金属を良好に分布させる方法は使用する金属の
種類、存在するイオン種およびそれらの分布状態
により異なる。すなわち、溶液の性質、PH、塩濃
度および使用前に塩溶液が熟成された期間に影響
されるのである。溶液の状態は、多数回浸漬の開
始時に担体の深部に溶液が浸透し、初期の段階で
発明の目的を妨げるような表面部への厚い被覆が
形成されない様に調整することが重要である。
この多数回浸漬法では、浸漬に約450℃を越え
ない温度での加熱で分解することができる金属塩
の溶液を用い、毎回浸漬した後、付着した塩を加
熱により分解するのが有利である。この様にして
用いるイリジウムおよびルテニウムの好ましい塩
を例示すれば、H2IrCl6、H3IrCl6、HIrCl2
（OH）2、IrCl3・H2O、（NH4）3IrCl6、（NH4）2Ir
Cl5（H2O）、〔Ir（NH3）4Cl2〕Cl、〔Ir（NH3）5
（H2O）〕Cl3、RuCl3、H3RuCl6、（NH4）3RuCl6、
〔Ru（NH3）4Cl2〕Clが挙げられる。塩化物を用い
れば特に有利な結果が得られる。好ましいイリジ
ウム触媒を製造するのに特に有用なのはヘキサク
ロロイリジウム酸塩、IrCl3・3HClまたはH3IrCl6
のような三塩化イリジウムの強酸溶液および三塩
化イリジウム水和物である。これらのイリジウム
塩溶液と三塩化ルテニウムの混合物はこれら二種
の金属を含有する触媒の製造に用いる浸漬液とし
て特に有利である。
選ばれた塩または塩類の水溶液または含水もし
くは無水のアルコール溶液（たとえば、水と混合
するメタノール、エタノール、イソプロパノー
ル、ｔ−ブタノールなど）は多数回浸漬に有用で
ある。一般に溶液には１当り約0.02〜１グラム
原子、有利には約0.1〜0.6グラム原子の金属また
は金属類が供給される様に塩を溶解させる。
アルコール溶液または水溶液を担体の浸漬前に
熟成させて用いれば、全体により満足すべき性能
を有したヒドラジン類分解用のイリジウム含有触
媒が得られることを見い出した。溶液を熟成させ
れば溶液がより均質になり、それゆえ触媒金属が
担体上に均一に分布されるばかりでなく、熟成溶
液を用いれば金属はより弱く吸着され、担体によ
りゆつくりと浸透し担体全体の内部表面により均
一に付着させることができる。この事実はイリジ
ウムを約0.02ｇ／mlおよび加えた塩酸に対し
0.15Mの割合で含有する三塩化イリジウムの水溶
液をアルミナ担体に吸着させる試験により示され
た。一夜放置して均質溶液を調製する。アルミナ
担体（表面積156m2／ｇ、孔容積0.343cm3／ｇ、比
熱容量0.18cal／ｇ・deg（20℃）および粒度100〜
200メツシユ）を内径１mmのカラムに充填して深
さ20.3〜22.9cm（８〜９インチ）のベツドを形成
し、その上に塩化イリジウム溶液を注ぐ。熟成溶
液を通過させた後、アルミナカラムの2.7cm（１
インチ1/16）は淡青緑色、次の7.0cm（２インチ
３／４）は青から淡緑色および次の0.6cm（1/4イン
チ）は薄黄色に着色される。この着色はやや弱い
吸着があることを示し、この種の塩溶液が急速に
担体へ浸透したことを立証している。これより濃
い酸溶液では着色帯はさらに広がり（尾を引き）、
より薄い溶液では広がらない。触媒反応的には三
塩化イリジウムを単独で用いる場合、希薄な酸溶
液で最良の結果が得られる。ヘキサクロロイリジ
ウム酸塩のイソプロパノール溶液から同一の担体
に吸着させて同様の結果を得た。新鮮な溶液では
非常に強い吸着が起こり、イリジウムはカラム頭
部に事実上補集され1.27cm（1/2インチ）の黒色
帯を形成する。熟成溶液を用いれば黒色部分はカ
ラム頭部に痕跡程度存在するのみであり、淡緑色
の帯が広く存在する。この様に熟成したそれ程強
く吸着しないイオンはアルミナにより深く浸透さ
せることができる。触媒の製造においてはこの事
は金属を内部の孔により均一に付着させることに
なる。
熟成した溶液を用いてより有利な触媒が製造で
きる機構は完全には解明されていない。アルコー
ル溶液の場合、触媒金属イオンが還元されてたと
えばIr3+が生じているかあるいは錯イオンが徐々
に形成されているらしい。改良の理由が何であ
れ、一般に浸漬に用いる溶液は選択された担体に
使用する前に少くとも24時間熟成するのが望まし
い。新鮮な溶液は強く付着して担体の周辺表面に
厚い被覆を形成し、連続して浸漬しても所望の深
部への浸透を達成することができない。
すでに指摘したように、溶液のPHは金属または
金属類の担体表面への付着に影響を与える。イリ
ジウム塩（たとえば三塩化イリジウム水和物、ヘ
キサクロロイリジウム酸塩、四塩化イリジウムな
ど）を用いる場合、PHは約0.5〜４の酸性が好ま
しく、PH約２〜３がより有利である。アルミナを
浸漬した後、水溶液のPHは少し増加する。これは
イリジウムを含有したイオン種と共に水素イオン
がアルミナに吸着されまたはアルミナと反応する
ためである。水素イオン濃度の減少により、多分
平衡はイリジウムの重合種の側に移動している。
浸漬を繰り返せば溶液は逐次濃縮される。この事
は連続浸漬の初期の段階において担体の深部に浸
透させることが重要である理由でもある。
しかし、金属のアミン錯化合物を用いた場合は
アルカリ溶液を使用することができる。多数回浸
漬にクロロペントアミンイリジウムの溶液を用い
ても有利であり、この場合、PH約８〜10のアンモ
ニア溶液が適している。
多数回浸漬を行う好ましい方法の一つは次の様
である。すなわち、選択された触媒担体を約10〜
60分間触媒金属の塩の溶液に浸して担体の孔に適
量の溶液を浸透させる。過剰の溶液は約１〜20分
で流出させ、担体を温風、好ましくは約120〜150
℃で乾燥する。部分的に乾燥した担体粒子をゆつ
くりと約250〜450℃に加熱して完全に乾燥させて
金属塩を部分的に分解する。通常、この操作は約
10〜60分で十分に完了する。この後、担体を冷却
し、この一連の処理を繰り返して必要量の触媒金
属の塩を付着させる。次いで前に示唆した様に還
元して必要な割合の触媒金属を得る。通常、少く
とも７回の浸漬操作が必要であり、一般に単一バ
ツチの浸漬溶液で処理するのがより経済的であ
り、担体で完全に補集されるまで繰り返し使用す
る。しかし、担体に使用している溶液に新鮮な触
媒金属の塩の溶液を連続的または断続的に加える
こともでき、あるいは他の方法で前述の所望量の
触媒金属を付着させることもできる。
出発物質としての金属塩又は塩類の付着された
分解生成物を最後に還元するために約250〜600℃
の気体水素を用いることができる。より一般的に
は還元は約300℃の窒素で希釈された水素で開始
するのが好ましく、温度を上昇し気体中の水素濃
度を増し、最後には約550℃で希釈しない水素を
用いて約30分間加熱して還元を完結させる。
次に実施例を挙げて本発明の触媒の製法を更に
詳しく説明する。
実施例 １
イリジウム／アルミナ触媒の製造（三塩化イリ
ジウムのアンモニア溶液を使用）：−
イリジウムを54.6％含有した三塩化イリジウム
25.0ｇを水85mlに50℃で加熱しながら溶解し、冷
却した後、3NNH4OH60mlを加えてイリジウム
のアンモニア溶液（イリジウム9.2ｇ／100ml）を
調製する。アルミナ担体は表面積156m2／ｇ、孔
容積0.34cm3／ｇおよび比熱容量0.19cal／ｇ・deg
（25℃）を有し、直径0.3cm（1/8インチ）の円筒
形である。平面間で測定した個々の破粋強さは平
均75.6N（17ポンド）である。この担体55ｇを上
記の溶液に10分間浸し、液を５分間流出させ、温
風で２〜５分間予備乾燥した後、15.2cm（６イン
チ）のペトリー皿に一層に並べホツトプレート上
で高温にして15分間乾燥する。更に、20ampの温
風器を用い25.4cm（10インチ）の距離から触媒に
温風を当てる。触媒温度は約380℃に上昇し、酸
および塩化アンモニウムの蒸気は放出される。物
質を冷却し秤量する。
前述の手順を６回繰り返して全溶液を消費す
る。その後、担体小片を乾燥窒素中で300℃に加
熱し、水素−窒素（約１：10）の混合物を300℃
で0.5時間触媒に通じて還元する。この間大部分
の塩化水素は発散する。触媒を窒素中で冷却した
後、空気中で酸化する。この後、各水100mlで３
回洗浄する。少量の塩化アルミニウム（恐らくオ
キシ塩化物）を除去する。しかし塩化アンモニウ
ムは検出されなかつた。洗浄過程は必要でないか
も知れないが、本例では未分解の塩化アンモニウ
ム（検出されず）を除去する為に行つた。
次いでホツトプレート上で乾燥する。
前述の方法で新しく調製した三塩化イリジウム
のアンモニア溶液を用いて触媒を２巡目の処理に
付す。この処理においても全溶液を吸着させるの
に６回の浸漬処理を要する。前述の手順で還元お
よび洗浄を行つた後、再び窒素中で300℃に加熱
し、続いて窒素−水素（１：10）中、300℃で0.5
時間および水素中、550℃で0.5時間加熱して触媒
の最終製品を得る。
この触媒はイリジウムを32重量％の割合で含有
する。22.2N（５ポンド）推力反応装置（内径2.6
cm（1.04インチ）、長さ8.9cm（3.5インチ）の円
筒）を用い、供給温度３〜５℃、供給速度13.6
ｇ／秒でヒドラジンの分解試験を行つた結果、良
好な燃焼が認められた。２〜４℃の反応装置で10
回スタートさせ、初期の点火遅れは25ミリ秒以下
であり、最後には90ミリ秒に増加した。定常圧は
1.26×10〜1.31×10atm（185〜192psig）が記録さ
れ、スタート時の過圧はなかつた。アンモニアの
分解は57〜62％であり、最終の触媒損失は燃焼１
分当り約１％であつた。
実施例 ２
実施例１の型のアルミナを分けてヘキサクロロ
イリジウム酸塩（H2IrCl6）の酸性水溶液に１時
間浸し触媒を調製する。触媒を脱液し、温風で乾
燥した後、380℃の熱風で約１時間分解する。イ
リジウム濃度が22ｇ／100mlの溶液を用いて上記
の手順を５回繰り返して触媒Ａを調製し、濃度６
ｇ／100mlの溶液を用いて上記手順を20回繰り返
して触媒Ｂを調製する。最後の浸漬および分解を
行つた後、500〜550℃で水素気体を流して還元す
る。結果を表１に示す。ヒドラジン分解試験は実
施例１と同様に行つた。
The present invention relates to a catalyst for decomposing hydrazine, and more particularly to a novel catalyst for advantageously decomposing hydrazine and alkyl-substituted hydrazine, and a method for producing the same. Hydrazine and lower alkyl-substituted hydrazines (hereinafter collectively referred to as hydrazines) are useful as single propellants for rockets and other thrust devices. Hydrazines generate heat and energy when decomposed, and can be used not only to operate jets for attitude control in rockets and spacecraft, but also to generate gas for operating turbines. Catalysts provided hitherto for the decomposition of hydrazines have had serious drawbacks. For example, platinum group metal catalysts are known (U.S. Patent No.
3081595 and 3086945). However, these catalysts do not meet all the stringent requirements for use in thrust devices and gas generators. These requirements include relatively low temperatures (e.g., liquid hydrazine is about 1.7°C (about 3.5°C) and catalyst temperature is about -17.8°C).
Includes the ability to initiate the decomposition of hydrazine at ℃ (approximately 0〓). Additionally, it must have an ignition delay of less than 100 milliseconds from a cold start and be capable of firing at least 10 times per minute without appreciable overpressure at start. In addition, 1093.3 often occurs in the decomposition of hydrazine.
Must be able to withstand high temperatures of around ℃ (200〓).
It must have adequate physical strength to withstand the handling it will receive when used in rocket applications, and it must still exhibit catalytic activity after being placed in space for about a year. Catalysts for decomposing hydrazine produced in the prior art do not meet these essential requirements. An important object of the present invention is to provide a catalyst that satisfies these requirements in the decomposition of hydrazines. Because hydrazine is a relatively stable chemical that can be stored for long periods in open-vent storage tanks, a highly active catalyst is required for spontaneous ignition at the high flow rates employed in rocket engines. In addition, the decomposition of hydrazine requires higher temperatures than normal catalytic reactions, so the catalyst must be very stable if it is to have the ability to reignite many times. The novel catalyst of the present invention satisfies these requirements and has a long shelf life as a spontaneous catalyst for decomposing hydrazines. Here, the autocatalyst refers to a catalyst that starts decomposition and sustains decomposition when hydrazines are injected into the catalyst at high speed in a rocket engine or gas generation chamber. Further advantages of the invention will become apparent from the description provided below. The inventors have discovered that a special type of iridium metal catalyst, deposited in a special manner at critical high concentrations on a specially shaped support, has a unique combination of properties that makes it desirable as a catalyst for the decomposition of hydrazines. It has been found that the aforementioned stringent requirements of high activity and good stability are met. The new catalyst has as an essential component a support that satisfies the following conditions.
The conditions are that the carrier has the following formula: S S 195 (C P +0.013 + 0.736V P ) [where S S is the specific surface area (m 2 /g), and C P is the specific heat capacity at about 25°C ( cal/g・deg), V P is the pore volume (cm 3 /
g). ] It is to have a specific surface area S S that satisfies the relationship shown below. Here V P must not be less than 0.1.
Such formulas are derived experimentally or theoretically, and are typically obtained through experiments. This type of support not only has a pore volume that is sufficient to retain the required amount of catalytic metal, which is essential for the new catalyst, without blocking the pores to the extent that it interferes with the catalysis of the hydrazines and catalytic metal, but also When the pores are filled with liquid hydrazine, the heat generated by wetting the porous catalyst results in a desirable average temperature increase of at least 20°C. Using new catalysts with this type of support, a smooth spontaneous decomposition of hydrazines occurs even under unfavorable starting conditions. Particularly preferably, the support has a specific surface area of about 100 to 300 m 2 /g, about
Pore volume of 0.3-0.5 cm 3 /g and approximately 44.5-133.4 N (approximately
It is an alumina carrier with a crushing strength of 10~30bs). Iridium has significant advantages not only when used alone as catalytic metal in the new catalyst, but also when used in particularly effective combination with ruthenium. In this combination, it is desirable to use iridium in a proportion of about 30 to 80 atomic percent in the mixture with ruthenium. In order for the catalyst to have the desired high activity necessary for the spontaneous decomposition of hydrazines, it is necessary that iridium or a mixture of iridium and ruthenium be present in the final product of the catalyst in a proportion of about 20-40% by weight. . In order for the new catalyst to be stable enough to undergo many consecutive starts without failure, the catalytic metal must be properly distributed on the surface of the support. The metals must be deposited as independent particles at sufficient distance from each other so that the catalytic metal particles do not melt or sinter together at the high temperatures generated by the decomposition of hydrazines. Most preferably a diameter of approx.
Metal particles of 10-100 Å are uniformly distributed on the support surface with an average distance of about 20-200 Å from each other. Most advantageously, the metal particles have a diameter of about 20 Å and a mutual distance of about 50 Å. The mutual distance here means an idealized distance measured along the carrier surface, and not the shortest distance through the inside of the pore wall. The desired distribution of catalytic metals is not possible with conventional catalyst manufacturing methods. Using the prior art techniques, the carrier is more or less uniformly and continuously coated with the catalytic metal, but special methods are required to avoid this. A desired amount of catalytic metal or mixture thereof is diffused deeply into the pores of the selected support, increasing the concentration of metal from the interior towards the surface to the surface portion of the support, particularly the peripheral skin of about 0.5 mm of the support particles. Parts need to be manufactured to a particularly high concentration. The shape of the carrier is advantageously a spherical or cylindrical piece, but other shapes can also be used. The surface of the carrier must not be excessively coated with the catalytic metal, which may unduly impede the penetration of the hydrazines to be decomposed. It is assumed that most of the decomposition of hydrazine occurs at the surface of the carrier, ie, at a thickness of 0.1 to 0.5 mm. The infiltrated metal (or mixture) likely has two effects: Namely, (1) heat is dispersed throughout the carrier to alleviate sudden thermal shock to the insulating support. (2) After the catalytic metal deposited in high concentration on the outer surface is gradually corroded by continuous combustion, it acts as a reaction catalyst. A particularly advantageous method for preparing the novel catalysts of the invention is the method in which the support is repeatedly immersed in dilute solutions of iridium salts with or without ruthenium salts. With each immersion, metal ions are adsorbed onto the carrier surface. When a concentrated solution is used, the metal ions are packed together in high concentrations, and the metal particles formed by decomposition and reduction are either too large or too close to each other. Simply drying after immersing in a dilute solution will leave seed crystals behind and the next deposit will occur at the same location, causing the same problem as when using a concentrated solution. Therefore, it is necessary to carry out a process to convert the metal ions before immersing it in a dilute solution. Furthermore, this treatment must have the effect of preventing the previously deposited salt from redissolving during the next immersion and promoting its deposition on the previously uncoated areas on the carrier surface. In multi-dip processes, to obtain the best catalytic performance, it is advantageous to degas the support during the first few dips to allow better penetration of the salt solution. The method for achieving good metal distribution varies depending on the type of metal used, the ionic species present, and their distribution state. It is influenced by the nature of the solution, the pH, the salt concentration and the length of time the salt solution was aged before use. It is important to adjust the condition of the solution so that the solution does not penetrate deep into the carrier at the beginning of multiple immersions and form a thick coating on the surface at an early stage that would impede the purpose of the invention. In this multiple dipping method, it is advantageous to use a solution of metal salts for dipping, which can be decomposed by heating at temperatures not exceeding about 450° C., and to decompose the adhering salts by heating after each dipping. . Examples of preferred salts of iridium and ruthenium used in this manner include H 2 I r Cl 6 , H 3 I r Cl 6 , HI r Cl 2
(OH) 2 , I r Cl 3・H 2 O, (NH 4 ) 3 I r Cl 6 , (NH 4 ) 2 I r
Cl 5 (H 2 O), [Ir(NH 3 ) 4 Cl 2 ]Cl, [Ir(NH 3 ) 5
(H 2 O)] Cl 3 , RuCl 3 , H 3 RuCl 6 , (NH 4 ) 3 RuCl 6 ,
Examples include [Ru(NH 3 ) 4 Cl 2 ]Cl. Particularly advantageous results are obtained with chlorides. Particularly useful in preparing the preferred iridium catalysts are the hexachloroiridates, IrCl3.3HCl or H3IrCl6
strong acid solutions of iridium trichloride such as iridium trichloride and iridium trichloride hydrate. Mixtures of these iridium salt solutions and ruthenium trichloride are particularly advantageous as dip liquids for the preparation of catalysts containing these two metals. Aqueous or hydrous or anhydrous alcoholic solutions (eg, methanol, ethanol, isopropanol, t-butanol, etc., mixed with water) of the selected salt or salts are useful for multiple dips. Generally, the salt is dissolved so that the solution provides about 0.02 to 1 gram atom of metal or metals per gram atom, preferably about 0.1 to 0.6 gram atom. It has been found that an iridium-containing catalyst for decomposing hydrazines having more satisfactory overall performance can be obtained by aging an alcoholic or aqueous solution before dipping the carrier. Aging the solution not only makes the solution more homogeneous and therefore the catalytic metal is evenly distributed on the support, but also the aged solution allows the metal to be more weakly adsorbed and penetrate more slowly into the support. A more uniform deposition can be achieved over the entire internal surface. This fact is based on approximately 0.02g/ml of iridium and hydrochloric acid added.
This was demonstrated by a test in which an aqueous solution of iridium trichloride containing a proportion of 0.15M was adsorbed onto an alumina support. Prepare a homogeneous solution by standing overnight. Alumina carrier (surface area 156 m 2 /g, pore volume 0.343 cm 3 /g, specific heat capacity 0.18 cal/g・deg (20℃) and particle size 100~
200 mesh) is packed into a column with an inner diameter of 1 mm to form a bed 20.3 to 22.9 cm (8 to 9 inches) deep, and the iridium chloride solution is poured onto it. After passing through the aging solution, 2.7 cm (1
1/16 inch) is colored pale blue-green, the next 7.0 cm (2 3/4 inch) is colored blue to light green, and the next 0.6 cm (1/4 inch) is colored light yellow. This coloration indicates a rather weak adsorption and proves that this type of salt solution rapidly penetrated into the support. If the acid solution is more concentrated than this, the colored band will spread further (it will have a tail).
It does not spread in dilute solutions. In terms of catalysis, when using iridium trichloride alone, the best results are obtained with a dilute acid solution. Similar results were obtained by adsorbing hexachloroiridate from an isopropanol solution onto the same support. In fresh solution, adsorption is so strong that the iridium is virtually trapped at the head of the column, forming a 1/2 inch black band. If a ripening solution is used, only traces of the black part will be present at the head of the column, and a wide pale green band will be present. Ions that are aged in this way and are not as strongly adsorbed can penetrate deeper into the alumina. In catalyst production, this results in a more uniform deposition of the metal into the internal pores. The mechanism by which more advantageous catalysts can be produced using aged solutions is not completely understood. In the case of alcohol solutions, it seems that the catalytic metal ions are reduced to produce, for example, Ir 3+ , or that complex ions are gradually formed. Whatever the reason for the improvement, it is generally desirable to age the solution used for steeping for at least 24 hours before use on the selected carrier. The fresh solution adheres strongly and forms a thick coating on the peripheral surface of the carrier, making it impossible to achieve the desired deep penetration even with successive immersions. As already pointed out, the pH of the solution affects the adhesion of the metal or metals to the support surface. When using an iridium salt (for example, iridium trichloride hydrate, hexachloroiridate, iridium tetrachloride, etc.), the acidic pH is preferably about 0.5 to 4, more preferably about 2 to 3. After soaking the alumina, the PH of the aqueous solution will increase a little. This is because hydrogen ions are adsorbed to or react with alumina along with ionic species containing iridium. The decrease in hydrogen ion concentration probably shifts the equilibrium toward the polymerized species of iridium.
If the dipping is repeated, the solution will be concentrated successively. This is also the reason why it is important to penetrate deep into the carrier in the early stages of continuous immersion. However, when a metal amine complex compound is used, an alkaline solution can be used. It is also advantageous to use solutions of chloropentamine iridium for multiple immersions, in which case ammonia solutions with a pH of about 8 to 10 are suitable. One preferred method for performing multiple immersions is as follows. That is, the selected catalyst support is about 10~
The support is immersed in the catalytic metal salt solution for 60 minutes to infiltrate the pores of the support with an appropriate amount of the solution. Excess solution is allowed to flow out in about 1-20 minutes, and the carrier is heated with hot air, preferably about 120-150
Dry at °C. The partially dried carrier particles are slowly heated to about 250-450°C to completely dry and partially decompose the metal salt. Typically this operation is about
It takes 10 to 60 minutes to complete. Thereafter, the carrier is cooled and this series of treatments is repeated to deposit the required amount of catalytic metal salt. It is then reduced as previously suggested to obtain the required proportions of catalytic metal. Typically, at least seven dipping operations are required, and it is generally more economical to treat with a single batch of dipping solution, which is used repeatedly until complete coverage of the carrier is achieved. However, fresh catalytic metal salt solution can also be added continuously or intermittently to the solution used for the support, or the desired amount of catalytic metal can be deposited in other ways. approximately 250-600°C for the final reduction of the attached decomposition products of the metal salt or salts as starting materials.
of gaseous hydrogen can be used. More generally, the reduction is preferably started with hydrogen diluted with nitrogen at about 300°C, increasing the temperature to increase the hydrogen concentration in the gas, and finally reducing with undiluted hydrogen at about 550°C. Heat for 30 minutes to complete reduction. Next, the method for producing the catalyst of the present invention will be explained in more detail with reference to Examples. Example 1 Preparation of an iridium/alumina catalyst (using an ammonia solution of iridium trichloride): - Iridium trichloride containing 54.6% iridium
25.0 g is dissolved in 85 ml of water while heating at 50°C, and after cooling, 60 ml of 3NNH 4 OH is added to prepare an ammonia solution of iridium (9.2 g of iridium/100 ml). The alumina support has a surface area of 156 m 2 /g, a pore volume of 0.34 cm 3 /g and a specific heat capacity of 0.19 cal/g・deg.
(25°C) and has a cylindrical shape with a diameter of 0.3 cm (1/8 inch). Individual fracture strength measured between planes averages 75.6N (17 lbs). 55 g of this carrier was soaked in the above solution for 10 minutes, the liquid was allowed to flow out for 5 minutes, and after pre-drying with warm air for 2-5 minutes, it was placed in a single layer in a 15.2 cm (6 inch) Petri dish and heated to high temperature on a hot plate. and dry for 15 minutes. Furthermore, hot air is applied to the catalyst from a distance of 25.4 cm (10 inches) using a 20 amp hot air fan. The catalyst temperature rises to about 380°C and acid and ammonium chloride vapors are released. Cool and weigh the substance. Repeat the above procedure 6 times to consume the entire solution. The support piece was then heated to 300°C in dry nitrogen and a hydrogen-nitrogen (approximately 1:10) mixture was heated to 300°C.
Pass through the catalyst for 0.5 h to reduce. During this time, most of the hydrogen chloride is released. After cooling the catalyst in nitrogen, it is oxidized in air. After this, 3 times with 100ml of water each.
Wash twice. Remove small amounts of aluminum chloride (possibly oxychloride). However, ammonium chloride was not detected. Although a washing step may not be necessary, it was performed in this example to remove undecomposed ammonium chloride (not detected). It is then dried on a hot plate. The catalyst is subjected to a second treatment using an ammonia solution of iridium trichloride freshly prepared as described above. In this treatment as well, six immersion treatments are required to adsorb the entire solution. After reduction and washing as described above, heating to 300 °C again in nitrogen followed by 0.5 °C at 300 °C in nitrogen-hydrogen (1:10)
Heating at 550 °C for 0.5 h in hydrogen and hydrogen yields the final product of the catalyst. This catalyst contains iridium in a proportion of 32% by weight. 22.2N (5 lb) thrust reactor (inner diameter 2.6
cm (1.04 inch), length 8.9 cm (3.5 inch) cylinder), feed temperature 3-5℃, feed rate 13.6
As a result of a hydrazine decomposition test conducted at g/sec, good combustion was observed. 10 in a reactor at 2-4℃
The initial ignition delay was less than 25 milliseconds and increased to 90 milliseconds at the end. The steady pressure is
1.26 x 10 to 1.31 x 10 atm (185 to 192 psig) was recorded, with no overpressure at start. The decomposition of ammonia is 57-62% and the final catalyst loss is combustion 1
It was about 1% per minute. Example 2 A catalyst is prepared by separating alumina of the type of Example 1 and soaking it in an acidic aqueous solution of hexachloroiridate (H 2 I r Cl 6 ) for 1 hour. After the catalyst is deliquified and dried with hot air, it is decomposed with hot air at 380°C for about 1 hour. Catalyst A was prepared by repeating the above procedure 5 times using a solution with an iridium concentration of 22 g/100 ml.
Catalyst B is prepared by repeating the above procedure 20 times using a solution of g/100 ml. After the final soaking and decomposition, it is reduced by flowing hydrogen gas at 500-550°C. The results are shown in Table 1. The hydrazine decomposition test was conducted in the same manner as in Example 1.
【表】
水素化学吸着量の大きい差は付着した金属の微
細状態に著しい差があることを示している。付着
金属の粒子が小さい程、水素化学吸着に用いられ
る面積さらにはヒドラジン類の分解に活性を有す
る触媒面積が大きくなる。全イリジウム含有量が
ほぼ等しいにもかかわらず、５回浸漬で製造した
触媒のイリジウム表面積は20回浸漬で製造した触
媒の表面積の約４分の１にすぎない。20回浸漬で
製造した触媒の金属の平均粒子径は約17Åであ
り、顕著なヒドラジン分解能を示す。
本例の二触媒の比較から触媒製造に際し浸漬回
数は少くとも７回以上必要なことが示される。
実施例 ３
一夜熟成したヘキサクロロイリジウム酸塩水溶
液および実施例１と同様のアルミナを用いて触媒
を製造する。アルミナはマツフル炉を用い700℃
で１時間加熱して用いる。浸漬用溶液はイリジウ
ムを0.29グラム原子／の割合で含有し、塩酸の
添加で約0.3Nにする。浸漬および分解を連続し
て20回繰り返す。浸漬時間を５〜10分間から６時
間まで変化させて担体中に所望の金属塩を浸透さ
せる。
実施例１の22.2N（５ポンド）推力反応装置を
用い、２〜４℃で10回スタートさせた結果、点火
遅れは初期には40ミリ秒以下、最後には80ミリ秒
であつた。1.26×10〜1.29×10atm（185〜
189psig）の定常圧が記録され、スタート時の過
圧は認められなかつた。触媒損失は0.5％／分で
あつた。
実施例 ４
イリジウムを0.29グラム原子／の割合で含有
する種々の塩溶液および同様のアルミナ担体を用
い、実施例２および３の手順を繰り返して触媒を
製造する。浸漬回数は17〜20回とし、付着した塩
は各浸漬後に加熱して分解する。触媒は0.3cm
（1/8インチ）の担体にイリジウムを30〜35重量％
割合で含有し、45cm3のベツドでヒドラジン分解に
用いる。ヒドラジン供給速度は13.6ｇ／秒であ
る。スタート温度を供給ヒドラジンおよび触媒共
に２〜４℃とし、各燃焼時間は60秒間とした。結
果を表２に示す。[Table] A large difference in the amount of chemically adsorbed hydrogen indicates a significant difference in the fine state of the deposited metal. The smaller the particles of the attached metal, the larger the area used for chemical adsorption of hydrogen and the larger the area of the catalyst active in decomposing hydrazines. Although the total iridium content is approximately equal, the iridium surface area of the catalyst prepared with 5 dips is only about one-fourth that of the catalyst prepared with 20 dips. The average metal particle size of the catalyst produced by immersion 20 times was approximately 17 Å, indicating remarkable hydrazine decomposition ability. A comparison of the two catalysts of this example shows that the number of immersions is required to be at least seven times during catalyst production. Example 3 A catalyst is prepared using a hexachloroiridate aqueous solution aged overnight and the same alumina as in Example 1. Alumina is produced at 700℃ using a Matsufuru furnace.
Heat for 1 hour before use. The dipping solution contains iridium in a proportion of 0.29 g atom/atom and is brought to approximately 0.3N by addition of hydrochloric acid. Repeat soaking and disassembly 20 times in succession. The soaking time is varied from 5-10 minutes to 6 hours to infiltrate the desired metal salt into the carrier. Using the 22.2 N (5 lb) thrust reactor of Example 1 and starting 10 times at 2-4°C, the ignition delay was less than 40 milliseconds initially and 80 milliseconds at the end. 1.26×10~1.29×10atm (185~
A steady pressure of 189 psig) was recorded, with no overpressure observed at start. Catalyst loss was 0.5%/min. Example 4 Catalysts are prepared by repeating the procedure of Examples 2 and 3 using various salt solutions containing iridium at a rate of 0.29 gram atom/a and similar alumina supports. The number of immersions is 17 to 20 times, and the attached salt is decomposed by heating after each immersion. Catalyst is 0.3cm
30-35 wt% iridium on (1/8 inch) support
It is used for hydrazine decomposition in a bed of 45cm3 . The hydrazine feed rate is 13.6 g/sec. The starting temperature was 2 to 4°C for both the supplied hydrazine and the catalyst, and each combustion time was 60 seconds. The results are shown in Table 2.
【表】【table】
【表】
実施例 ５
イリジウムおよびルテニウムの混合物ならびに
実施例１のアルミナ担体を用い、実施例２および
３の手順を繰り返して触媒を製造し、実施例１と
同様にヒドラジン分解試験を行つた。結果を表３
に示す。いずれの触媒もイリジウムおよびルテニ
ウムを合して25〜32重量％の割合で含有してお
り、製造に際しては10回以上浸漬を行つた。[Table] Example 5 A catalyst was prepared by repeating the procedures of Examples 2 and 3 using a mixture of iridium and ruthenium and the alumina support of Example 1, and a hydrazine decomposition test was conducted in the same manner as in Example 1. Table 3 shows the results.
Shown below. All catalysts contained iridium and ruthenium in a combined proportion of 25 to 32% by weight, and were immersed 10 times or more during production.
【表】
実施例 ６
姿勢制御や補助用バーニヤ推力に必要な低推力
（約１ポンドまたはそれ以下）を発生する制御用
小型モータでは小量のヒドラジンを断続的に分解
しなければならない。その為に次の方法で製造し
た触媒が特に用いられる。すなわち、実施例１の
アルミナと同じ性質の16〜28メツシユの粒状アル
ミナ担体を同様の三塩化イリジウムのアンモニア
溶液に平均15分間で７回浸漬してイリジウムを31
重量％の割合で含有する触媒を製造する。
この触媒2.3cm3を小型反応装置に用い非常に良
好な燃焼性能を有することを確かめた。約３℃で
各８mlのヒドラジンを９秒間ずつ少くとも６回連
続的に燃焼させた。触媒を反応装置中に６週間放
置した後に繰り返し再燃焼させても同様に良好な
結果が得られた。
以上の実施例では担体としてアルミナを用いた
が、これはアルミナが特に活性の高い安定な触媒
を製造するのに優れているためであり、担体はア
ルミナに限られるものではない。本発明の新規な
ヒドラジン類分解用触媒は前述の関係式を満足す
る比表面積および適当な孔容積を有する他の担体
を用いて製造することができる。担体には、たと
えば酸化ジルコニウム、炭化硼素、窒化チタン、
窒化ジルコニウム、窒化硼素、炭化ジルコニウ
ム、炭素、硼化ジルコニウム、ジルコニウム酸カ
ルシウムおよび類似の高耐火性担体が包含され
る。アルミナの中でもゲル（たとえばゼラチン状
ベーム石）から得た高安定型のものが特に好まし
く用いられる。
本発明の触媒はヒドラジンの分解だけではなく
置換ヒドラジン（たとえばモノメチルヒドラジ
ン、非対称ジメチルヒドラジンなど）の分解にも
用いることができる。[Table] Example 6 Small amounts of hydrazine must be decomposed intermittently in small control motors that generate the low thrust (about 1 pound or less) required for attitude control and auxiliary vernier thrust. For this purpose, catalysts prepared in the following manner are particularly used. That is, a granular alumina support of 16 to 28 meshes having the same properties as the alumina of Example 1 was immersed in a similar ammonia solution of iridium trichloride seven times for an average of 15 minutes to add 31 iridium.
A catalyst containing % by weight is prepared. We used 2.3 cm 3 of this catalyst in a small reactor and confirmed that it had very good combustion performance. At least six consecutive 8 ml hydrazine burns of 9 seconds each were carried out at about 3°C. Similar results were obtained when the catalyst was left in the reactor for 6 weeks and then repeatedly reburned. In the above examples, alumina was used as the carrier, but this is because alumina is particularly excellent for producing a stable catalyst with high activity, and the carrier is not limited to alumina. The novel catalyst for decomposing hydrazines of the present invention can be manufactured using other carriers having a specific surface area and an appropriate pore volume that satisfy the above-mentioned relationship. Examples of carriers include zirconium oxide, boron carbide, titanium nitride,
Included are zirconium nitride, boron nitride, zirconium carbide, carbon, zirconium boride, calcium zirconate and similar highly refractory supports. Among aluminas, highly stable aluminas obtained from gels (eg, gelatinous boehmite) are particularly preferably used. The catalyst of the present invention can be used not only for decomposing hydrazine but also for decomposing substituted hydrazines (eg, monomethylhydrazine, asymmetric dimethylhydrazine, etc.).
Claims (1)
るヒドラジン類分解用触媒であつて、 該担体が約0.3〜0.5cm3／ｇの孔容積および約
100〜300m2／ｇの比表面積を有するアルミナであ
り、 該金属成分が、前記担体に触媒重量の約20〜40
重量％の割合で付着したイリジウムまたはイリジ
ウムとルテニウムの混合物であり、かつ該金属成
分の粒子がヒドラジン分解温度で一緒に焼結また
は溶融することのないよう相互に充分な間隔をお
いて前記担体の孔の中に分布されているヒドラジ
ン類分解用触媒。 ２ 担体が、約44.5〜133.4N（約10〜30lbs）の破
砕強さを有するアルミナである特許請求の範囲第
１項記載の触媒。 ３ 触媒金属成分がイリジウムのみである特許請
求の範囲第２項記載の触媒。 ４ 触媒金属成分がイリジウムおよびルテニウム
の混合物である特許請求の範囲第２項記載の触
媒。 ５ イリジウムの混合割合が30〜80原子％である
特許請求の範囲第４項記載の触媒。 ６ 担体および該担体に付着した金属成分からな
るヒドラジン類分解用触媒を製造するにあたり、 担体の孔にイリジウムを必須成分とする触媒金
属の塩を含有する溶液を浸透させ、該溶液を含有
した担体を乾燥させて前記の塩を担体の孔に付着
させ、次いで該担体を加熱して前記の塩を分解
し、更に担体の溶液への浸漬、乾燥および塩の分
解から成る上記の操作を少くとも７回繰り返した
後、水素気流中約200〜500℃に加熱することによ
り、前記の塩の分解物を触媒活性を有する金属に
変換することを特徴とする、 該担体が約0.3〜0.5cm3／ｇの孔容積および約
100〜300m2／ｇの比表面積を有するアルミナであ
り、 該金属成分が、前記担体に触媒重量の約20〜40
重量％の割合で付着したイリジウムまたはイリジ
ウムとルテニウムの混合物であり、かつ該金属成
分の粒子がヒドラジン分解温度で一緒に焼結また
は溶融することのないよう相互に充分な間隔をお
いて前記担体の孔の中に分布されているヒドラジ
ン類分解用触媒の製法。 ７ 触媒金属の塩は450℃を越えない温度で分解
されるものであり、塩の溶液は金属を約0.02〜
0.6グラム原子／の割合で含有し、そのPHが約
0.5〜４である特許請求の範囲第６項記載の製法。 ８ 触媒金属がイリジウムのみである特許請求の
範囲第６項記載の製法。 ９ 触媒金属がイリジウムおよびルテニウムの混
合物である特許請求の範囲第６項記載の製法。 １０ 担体の浸漬を使用前に少くとも24時間熟成
した金属塩の溶液を用いて行うものである特許請
求の範囲第７項記載の製法。 １１ 担体および該担体に付着した金属成分から
なるヒドラジン類分解用触媒を製造するにあた
り、 担体を、450℃を越えない温度で分解されるイ
リジウム塩をイリジウムが約0.02〜0.6グラム原
子／の割合で含有する様に溶解したアルカリ性
アンモニア溶液に浸し、生成した溶液を含有する
アルミナを乾燥してイリジウム塩を担体の孔に付
着させた後、アルミナを加熱して塩を分解させ、
更に浸漬、乾燥および分解の手順を全体で少くと
も７回繰り返してイリジウムを約20〜40重量％含
有させた後、約200〜500℃の水素で加熱してイリ
ジウム塩を分解し触媒活性を有する金属に変換す
ることを特徴とする、 該担体が約0.3〜0.5cm3／ｇの孔容積および約
100〜300m2／ｇの比表面積を有するアルミナであ
り、 該金属成分が、前記担体に触媒重量の約20〜40
重量％の割合で付着したイリジウムまたはイリジ
ウムとルテニウムの混合物であり、かつ該金属成
分の粒子がヒドラジン分解温度で一緒に焼結また
は溶融することのないよう相互に充分な間隔をお
いて前記担体の孔の中に分布されているヒドラジ
ン類分解用触媒の製法。[Scope of Claims] 1. A catalyst for decomposing hydrazines comprising a carrier and a metal component attached to the carrier, wherein the carrier has a pore volume of about 0.3 to 0.5 cm 3 /g and a pore volume of about 0.3 to 0.5 cm 3 /g and
alumina having a specific surface area of 100 to 300 m 2 /g, and the metal component is applied to the carrier in an amount of about 20 to 40
% by weight of iridium or a mixture of iridium and ruthenium, and the particles of said metal component are spaced sufficiently apart from each other so that they do not sinter or melt together at the hydrazine decomposition temperature. Catalyst for decomposing hydrazines distributed in the pores. 2. The catalyst of claim 1, wherein the support is alumina having a crush strength of about 10-30 lbs. 3. The catalyst according to claim 2, wherein the catalytic metal component is only iridium. 4. The catalyst according to claim 2, wherein the catalytic metal component is a mixture of iridium and ruthenium. 5. The catalyst according to claim 4, wherein the mixing ratio of iridium is 30 to 80 atomic %. 6. In producing a catalyst for decomposing hydrazines consisting of a carrier and a metal component attached to the carrier, a solution containing a salt of a catalytic metal having iridium as an essential component is permeated into the pores of the carrier, and a carrier containing the solution is prepared. to deposit said salt in the pores of the carrier, then heating said carrier to decompose said salt, and at least the above operation consisting of dipping the carrier in a solution, drying and decomposing the salt. After repeating seven times, the decomposition product of the salt is converted into a metal having catalytic activity by heating to about 200-500°C in a hydrogen stream, wherein the support is about 0.3-0.5 cm 3 /g pore volume and approx.
alumina having a specific surface area of 100 to 300 m 2 /g, and the metal component is applied to the carrier in an amount of about 20 to 40
% by weight of iridium or a mixture of iridium and ruthenium, and the particles of said metal component are spaced sufficiently apart from each other so that they do not sinter or melt together at the hydrazine decomposition temperature. A method for producing a catalyst for decomposing hydrazines distributed in pores. 7 Salts of catalytic metals are decomposed at temperatures not exceeding 450°C, and salt solutions decompose metals at approximately 0.02 to
Contains at a rate of 0.6 g atom/, and its pH is approximately
The manufacturing method according to claim 6, wherein the molecular weight is 0.5 to 4. 8. The manufacturing method according to claim 6, wherein the catalytic metal is only iridium. 9. The method according to claim 6, wherein the catalytic metal is a mixture of iridium and ruthenium. 10. The method according to claim 7, wherein the carrier is immersed in a solution of the metal salt that has been aged for at least 24 hours before use. 11 In producing a catalyst for decomposing hydrazines consisting of a carrier and a metal component attached to the carrier, the carrier is mixed with an iridium salt that is decomposed at a temperature not exceeding 450°C at a ratio of about 0.02 to 0.6 gram atom of iridium. The alumina containing the resulting solution is dried to adhere the iridium salt to the pores of the carrier, and then the alumina is heated to decompose the salt.
Further, the steps of soaking, drying and decomposition are repeated at least seven times in total to obtain an iridium content of about 20 to 40% by weight, and then heated with hydrogen at about 200 to 500°C to decompose the iridium salt and have catalytic activity. characterized in that the support has a pore volume of about 0.3 to 0.5 cm 3 /g and a
alumina having a specific surface area of 100 to 300 m 2 /g, and the metal component is applied to the carrier in an amount of about 20 to 40
% by weight of iridium or a mixture of iridium and ruthenium, and the particles of said metal component are spaced sufficiently apart from each other so that they do not sinter or melt together at the hydrazine decomposition temperature. A method for producing a catalyst for decomposing hydrazines distributed in pores.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7832668A GB2027357B (en) | 1978-08-08 | 1978-08-08 | Catalyst for hydrazine decomposition and method for preparing such catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5528719A JPS5528719A (en) | 1980-02-29 |
| JPH0113900B2 true JPH0113900B2 (en) | 1989-03-08 |
Family
ID=10498934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10136778A Granted JPS5528719A (en) | 1978-08-08 | 1978-08-18 | Catalyst for decomposing hydrazines and its preparation |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5528719A (en) |
| GB (1) | GB2027357B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2630535B1 (en) * | 1988-04-20 | 1990-11-02 | Air Liquide | POROUS MASS FOR A HEAT EXCHANGER AND ITS APPLICATION TO A JOULE-THOMSON COOLER |
| JP3245605B2 (en) * | 1991-02-15 | 2002-01-15 | 独立行政法人産業技術総合研究所 | Method for producing catalyst for hydrazine decomposition |
| JP3752529B2 (en) * | 2001-03-14 | 2006-03-08 | 独立行政法人産業技術総合研究所 | Iridium support material, iridium support method, and iridium support catalyst |
| CN114229792B (en) * | 2021-11-16 | 2023-07-25 | 西安航天动力试验技术研究所 | Method and device for preparing hydrogen by catalyzing hydrazine decomposition by nickel-iridium-based supported catalyst |
| CN115770569A (en) * | 2022-11-21 | 2023-03-10 | 西安航天动力研究所 | Preparation method of ruthenium catalyst |
| CN115739079A (en) * | 2022-11-21 | 2023-03-07 | 西安航天动力研究所 | Method for synthesizing iridium catalyst in one step |
| CN117724555B (en) * | 2024-02-07 | 2024-04-26 | 昆明然涛金属材料有限公司 | Temperature control system and control method for iridium-based metal safety production |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3086945A (en) * | 1959-07-16 | 1963-04-23 | Engelhard Ind Inc | Catalytic decomposition of 1, 1-dimethylhydrazine |
| JPS5194491A (en) * | 1973-04-19 | 1976-08-19 |
-
1978
- 1978-08-08 GB GB7832668A patent/GB2027357B/en not_active Expired
- 1978-08-18 JP JP10136778A patent/JPS5528719A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3086945A (en) * | 1959-07-16 | 1963-04-23 | Engelhard Ind Inc | Catalytic decomposition of 1, 1-dimethylhydrazine |
| JPS5194491A (en) * | 1973-04-19 | 1976-08-19 |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2027357B (en) | 1982-10-27 |
| GB2027357A (en) | 1980-02-20 |
| JPS5528719A (en) | 1980-02-29 |
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