JPH0550340B2 - - Google Patents
Info
- Publication number
- JPH0550340B2 JPH0550340B2 JP61155036A JP15503686A JPH0550340B2 JP H0550340 B2 JPH0550340 B2 JP H0550340B2 JP 61155036 A JP61155036 A JP 61155036A JP 15503686 A JP15503686 A JP 15503686A JP H0550340 B2 JPH0550340 B2 JP H0550340B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- palladium
- rhodium
- ozone
- cerium
- 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 - Lifetime
Links
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 50
- 239000003054 catalyst Substances 0.000 claims description 45
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 31
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims description 30
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 26
- 229910052763 palladium Inorganic materials 0.000 claims description 24
- 239000010948 rhodium Substances 0.000 claims description 23
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 23
- 229910052703 rhodium Inorganic materials 0.000 claims description 20
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 16
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 16
- 229910052697 platinum Inorganic materials 0.000 claims description 15
- 238000000354 decomposition reaction Methods 0.000 claims description 14
- 239000000919 ceramic Substances 0.000 claims description 3
- 229910003450 rhodium oxide Inorganic materials 0.000 claims description 3
- 239000013543 active substance Substances 0.000 claims 2
- 229910003445 palladium oxide Inorganic materials 0.000 claims 1
- 239000002002 slurry Substances 0.000 description 14
- 238000000034 method Methods 0.000 description 13
- 239000000843 powder Substances 0.000 description 13
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 10
- 229910052684 Cerium Inorganic materials 0.000 description 9
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 8
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- FGHSTPNOXKDLKU-UHFFFAOYSA-N nitric acid;hydrate Chemical compound O.O[N+]([O-])=O FGHSTPNOXKDLKU-UHFFFAOYSA-N 0.000 description 4
- 239000007858 starting material Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229910052878 cordierite Inorganic materials 0.000 description 3
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 3
- 230000009970 fire resistant effect Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- VXNYVYJABGOSBX-UHFFFAOYSA-N rhodium(3+);trinitrate Chemical compound [Rh+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VXNYVYJABGOSBX-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- -1 spodiume Chemical compound 0.000 description 3
- 239000002699 waste material Substances 0.000 description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- SONJTKJMTWTJCT-UHFFFAOYSA-K rhodium(iii) chloride Chemical compound [Cl-].[Cl-].[Cl-].[Rh+3] SONJTKJMTWTJCT-UHFFFAOYSA-K 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005979 thermal decomposition reaction Methods 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- 229910000505 Al2TiO5 Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229910002060 Fe-Cr-Al alloy Inorganic materials 0.000 description 1
- OKIZCWYLBDKLSU-UHFFFAOYSA-M N,N,N-Trimethylmethanaminium chloride Chemical compound [Cl-].C[N+](C)(C)C OKIZCWYLBDKLSU-UHFFFAOYSA-M 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910000323 aluminium silicate Inorganic materials 0.000 description 1
- HEHRHMRHPUNLIR-UHFFFAOYSA-N aluminum;hydroxy-[hydroxy(oxo)silyl]oxy-oxosilane;lithium Chemical compound [Li].[Al].O[Si](=O)O[Si](O)=O.O[Si](=O)O[Si](O)=O HEHRHMRHPUNLIR-UHFFFAOYSA-N 0.000 description 1
- IXSUHTFXKKBBJP-UHFFFAOYSA-L azanide;platinum(2+);dinitrite Chemical compound [NH2-].[NH2-].[Pt+2].[O-]N=O.[O-]N=O IXSUHTFXKKBBJP-UHFFFAOYSA-L 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000003421 catalytic decomposition reaction Methods 0.000 description 1
- 150000001785 cerium compounds Chemical class 0.000 description 1
- VGBWDOLBWVJTRZ-UHFFFAOYSA-K cerium(3+);triacetate Chemical compound [Ce+3].CC([O-])=O.CC([O-])=O.CC([O-])=O VGBWDOLBWVJTRZ-UHFFFAOYSA-K 0.000 description 1
- GHLITDDQOMIBFS-UHFFFAOYSA-H cerium(3+);tricarbonate Chemical compound [Ce+3].[Ce+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O GHLITDDQOMIBFS-UHFFFAOYSA-H 0.000 description 1
- UNJPQTDTZAKTFK-UHFFFAOYSA-K cerium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Ce+3] UNJPQTDTZAKTFK-UHFFFAOYSA-K 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000007794 irritation Effects 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 1
- 239000000391 magnesium silicate Substances 0.000 description 1
- 229910052919 magnesium silicate Inorganic materials 0.000 description 1
- 235000019792 magnesium silicate Nutrition 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000006262 metallic foam Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- QEFYFXOXNSNQGX-UHFFFAOYSA-N neodymium atom Chemical compound [Nd] QEFYFXOXNSNQGX-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- PIBWKRNGBLPSSY-UHFFFAOYSA-L palladium(II) chloride Chemical compound Cl[Pd]Cl PIBWKRNGBLPSSY-UHFFFAOYSA-L 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 229910052670 petalite Inorganic materials 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- AABBHSMFGKYLKE-SNAWJCMRSA-N propan-2-yl (e)-but-2-enoate Chemical compound C\C=C\C(=O)OC(C)C AABBHSMFGKYLKE-SNAWJCMRSA-N 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 210000002345 respiratory system Anatomy 0.000 description 1
- YWFDDXXMOPZFFM-UHFFFAOYSA-H rhodium(3+);trisulfate Chemical compound [Rh+3].[Rh+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O YWFDDXXMOPZFFM-UHFFFAOYSA-H 0.000 description 1
- PJRGNVSDUQPLCM-UHFFFAOYSA-H rhodium(3+);trisulfite Chemical compound [Rh+3].[Rh+3].[O-]S([O-])=O.[O-]S([O-])=O.[O-]S([O-])=O PJRGNVSDUQPLCM-UHFFFAOYSA-H 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 239000005437 stratosphere Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- JUWGUJSXVOBPHP-UHFFFAOYSA-B titanium(4+);tetraphosphate Chemical compound [Ti+4].[Ti+4].[Ti+4].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O JUWGUJSXVOBPHP-UHFFFAOYSA-B 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Landscapes
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Description
＜産業上の利用分野＞
本発明はオゾン分解触媒、特にガス中に含有さ
れるオゾンを接触的に分解する触媒およびその製
造方法に関する。
＜従来の技術とその問題点＞
オゾンは強い酸化能を有し、分解すると無害な
酸素になるために脱臭、殺菌、漂白または排水中
のCOD減少等の目的でさまざまな分野において
幅広く利用されている。しかし処理に利用された
オゾンは一部未反応のまま大気中に放出されるた
めに光化学スモツグ等の二次公害を発生させる恐
れがある。また、航空機が成層圏を飛行する場合
機内にオゾンを含む空気が導入されるため乗客や
搭乗員に悪影響を及ぼす危険性がある。
さらに、最近、各種の高電圧発生装置を組み込
んだ機器、例えば乾式の複写機等からのオゾン発
生が問題になつており、これ等の機器は主に室内
に置かれるためにオゾンの発生は微量であつても
室内が汚染される。
オゾンの臭いは1ppm以下の濃度で感知でき、
2ppm以上の濃度では呼吸器系に刺激を引き起こ
し、人体に有害となるために各種の発生源から排
出されるオゾンを除去し、無害化する必要があ
る。
従来、用いられてきた廃オゾン処理技術として
は活性炭法、薬液洗浄法および熱分解法がある。
活性炭法は低濃度オゾンの処理に利用されている
が、オゾン分解の進行に伴つて、活性炭が消耗す
るために補充する必要があり、また高濃度のオゾ
ンを処理する場合は反応熱により活性炭自身が発
火、燃焼する危険性があるので取り扱い上問題が
ある。
薬液洗浄法は還元性物質の水溶液で廃オゾンを
洗浄するために処理コストが高く、排水処理の問
題も生じる。
熱分解法は分解効率を上げるためには300℃以
上の加熱が必要であり、多量の排ガスを処理する
ためには加熱費用がかかり、処理コストが高くな
るなどの欠点がある。
一方、近年廃オゾン処理方法として触媒分解法
が研究されており、この方法は発火、爆発の危険
性がなく、排水処理も不要であり、低コストでオ
ゾンを分解除去できるために有利な方法とされて
いる。
オゾン分解触媒にはニツケル、マンガン、コバ
ルト等の酸化物を用いた触媒（例えば特開昭59−
66347号、特開昭60−97049号等）や、貴金属系の
触媒（例えば特開昭56−70823号、特開昭57−
122942号等）が知られているが、それぞれ室温か
ら100℃での低温度領域での活性が低く、また実
用触媒としての分解効率が低く、耐久性にも問題
があるので、低温度領域で高活性高耐久性を示す
触媒の提供が要望されている。
＜発明の目的＞
本発明の目的は、ガス中に含まれるオゾンを酸
素へ接触的に分解するにあたり、低温活性に優
れ、耐久性の高いオゾン分解触媒を提供すること
にある。
＜問題点を解決するための手段＞
本発明者らは、上記目的に沿つて問題点を検討
した結果、耐火性三次元構造体に白金、パラジウ
ムおよびロジウムからなる群から選択される少な
くとも１種の元素と酸化セリウムとからなる触媒
活性物質および活性アルミナとが担持せしめられ
てなるオゾン分解触媒が100℃以下、特に20〜30
℃の低温でも優れたオゾン分解性能を示し、且つ
耐久性にも優れることを見出し、本発明を完成す
るに至つた。すなわち、従来の貴金属系触媒が
鉄、コバルト、ニツケル等の第族非貴金属酸化
物を併用して使用するのに対して、本発明の触媒
の特徴は酸化セリウムを白金、パラジウムおよび
ロジウムからなる群から選択される少なくとも１
種の元素と共に用い、かつ通気性に優れた一体構
造を有する耐火性三次元構造体に担持せしめたこ
とにある。一般に酸化セリウムは酸素の吸脱着に
優れた酸化物であることは、特に自動車の排ガス
中の一酸化炭素、炭化水素および窒素酸化物の同
時除去用触媒に添加されることからよく知られて
いることである。このような特性を有する酸化セ
リウムはオゾンの吸着あるいは分解にも優れ白
金、パラジウムおよびロジウムからなる群から選
択される少なくとも１種の元素とさらに活性アル
ミナと共に触媒組成物とした触媒が優れたオゾン
分解性能を有することを知見したのである。
本発明に使用される活性アルミナは、粉末状で
使うことが好ましく、比表面積50〜180m2／ｇの
活性アルミナが好ましい。その結晶形としては、
ガンマー、デルタ、シーター、カイ、カツパ、イ
ータの形をとるものが使用可能である。また必要
に応じてこの活性アルミナを安定化するためにラ
ンタン、ネオジウム、プラセオジウム等の希土類
元素またはカルシウム、バリウム等のアルカリ土
類元素の少なくとも１種を0.1〜３重量％担持さ
れた活性アルミナも使用可能である。
本発明に使用される白金の出発原料としては、
塩化白金酸、ジニトロジアンミン白金等が使用さ
れ、パラジウムの出発原料としては、硝酸パラジ
ウム、塩化パラジウム、パラジウムスルフイト錯
塩、及びパラジウムテトラミンクロライド等が好
ましい。またロジウムの出発原料としては、硝酸
ロジウム、塩化ロジウム、硫酸ロジウム、ロジウ
ムスルフイト錯塩、及びロジウムアンミン錯塩等
が好ましい。白金、パラジウムおよびロジウムか
らなる群から選択される少なくとも１種の元素の
担持量は、触媒１当り合計で0.2〜５ｇ、好ま
しくは0.4〜３ｇの範囲である。特に好ましくは
パラジウムおよびロジウムを上記の量担持せしめ
たものである。
本発明で使用されるセリウムの出発原料として
は、水溶性の化合物が好ましく、硝酸セリウム、
酢酸セリウムが好ましく用いられる。その他に酸
化セリウム、炭酸セリウム、水酸化セリウム等の
水不溶性のセリウム化合物も活性アルミナと混合
して使用される。セリウムの使用量は酸化セリウ
ムとして触媒１当り１〜20ｇ、好ましくは３〜
10ｇの範囲で使用される。これら活性アルミナと
白金、パラジウムおよびロジウムからなる群から
選択される少なくとも１種の元素と酸化セリウム
との合計の使用量は触媒１当り30〜300ｇ、好
ましくは60〜170ｇの範囲で使用される。
本発明において使用される耐火性三次元構造体
は、通常セラミツクハニカム担体と称されるもの
が好ましく、特にコージエライト、ムライト、α
−アルミナ、ジルコニア、チタニア、リン酸チタ
ン、アルミニウムチタネート、ペタライト、スポ
ジユメン、アルミノシリケート、珪酸マグネシウ
ムなどを材料とするハニカム担体が好ましく、中
でもコージエライト質のものが好ましい。その
他、ステンレスまたはFe−Cr−Al合金などの如
き酸化抵抗性を持つ耐熱性金属を用いて一体構造
体としたものも使用される。そのガス通過口（セ
ル型状）の形は、６角形、４角形、３角形または
コルゲーシヨン型のいずれであつても良く、セル
密度（セル数／単位断面積）は100〜600セル／平
方インチであれば十分に使用可能で好結果を与え
る。
その他本発明において使用される耐火性三次元
構造体としては、アルミナ、アルミナ−シリカ、
シリカ、チタニア等の無機質繊維状担体もしくは
セラミツクフオームまたは金属発泡体等を挙げる
ことができる。
本発明による触媒は例えば次の方法によつて製
造することができる。
(1) 白金、パラジウムおよびロジウムよりなる群
から選択される少なくとも１種の元素の水溶性
塩およびセリウムの水溶性の塩の水溶液を混合
し、活性アルミナ粉末に含浸担持し、乾燥し、
空気中300〜800℃で焼成し、アルミナ上に白
金、パラジウムおよび／またはロジウムとセリ
ウムとを水不溶性の形で固定化する。次いでこ
の触媒組成物に希硝酸水を添加して、ボールミ
ル等を用いて湿式粉砕することにより、スラリ
ーを調製する。該スラリーを一体構造を有する
耐火性三次元構造体に担持することにより完成
触媒とする。
(2) 白金、パラシウムおよびロジウムよりなる群
から選択される少なくとも１種の元素の水溶性
塩の水溶液を活性アルミナに含浸担持し、乾燥
し、空気中300〜800℃で焼成し、アルミナ上に
白金、パラジウムおよび／またはロジウムを水
不溶性の形で固定する。次いでこれに所定量の
水不溶性セリウム源を加え、希硝酸水を添加し
てボールミル等を用いて湿式粉砕することによ
りスラリーを調製する。該スラリーを一体構造
を有する耐火性三次元構造体に担持することに
より完成触媒とする。
＜実施例＞
以下実施例にて本発明を更に詳細に説明する
が、本発明はこれら実施例のみに限定されるもの
ではない。
実施例 １
比表面積150m2／ｇの活性アルミナ1352ｇに、
16.7ｇのパラジウムを含む硝酸パラジウム、1.9
ｇのロジウムを含む硝酸ロジウムおよび106ｇの
セリウムを含む硝酸セリウムを混合した水溶液
1285c.c.を浸漬し、30分間充分混合し、150℃で３
時間乾燥したのち、空気中600℃で２時間焼成し
て、パラジウム、ロジウムおよびセリウム含有ア
ルミナ粉体を調製した。この粉体を希硝酸水と共
にボールミルで20時間湿式粉砕し、スラリーを調
製した。このスラリーを市販コージエライト質ハ
ニカム担体（日本碍子株式会社製）で、横断面が
１平方インチ当り300個のガス流通セルを有する
外径93mmφ、長さ102mmの円柱状の担体に約１分
間浸漬し、その後スラリーより取り出し、セル内
の過剰スラリーを圧縮空気でブローして、全セル
内の目詰りを除去し、次いで130℃で３時間乾燥
して完成触媒を得た。この触媒は、１当りアル
ミナ73ｇ、酸化セリウム７ｇ、パラジウム0.9ｇ、
ロジウム0.1ｇが担持されていた。
実施例 ２
実施例１と同様にして塩化白金酸、硝酸パラジ
ウムおよび硝酸セリウムを使用して、白金、パラ
ジウムおよびセリウム含有アルミナ粉体を調製し
た。次いでこの粉体をスラリーにして１当り82
ｇ、酸化セリウム８ｇ、白金0.15ｇおよびパラジ
ウム0.85ｇが担持された完成触媒を得た。
実施例 ３
実施例１と同様にして塩化白金酸、硝酸ロジウ
ムおよび硝酸セリウムを使用して、白金、ロジウ
ムおよびセリウム含有アルミナ粉体を調製した。
次いでこの粉体をスラリーにして１当り90ｇ、
酸化セリウム10ｇ、白金0.4ｇおよびロジウム
0.04ｇが担持された完成触媒を得た。
実施例 ４
比表面積120m2／ｇの活性アルミナ1712ｇに、
16.2ｇのパラジウムを含む硝酸パラジウムと1.8
ｇのロジウムを含む塩化ロジウムを混合した水溶
液1626c.c.を浸漬し、30分間充分混合し、150℃で
３時間乾燥したのち、空気中650℃で２時間焼成
して、パラジウムおよびロジウム含有アルミナ粉
体を調製した。この粉体に270ｇの酸化セリウム
を加え、希硝酸水と共にボールミルで湿式粉砕
し、スラリーを調製した。このスラリーを以下実
施例１と同様に同じハニカム担体に担持して完成
触媒を得た。この触媒は、１当りアルミナ95
ｇ、酸化セリウム15ｇ、パラジウム0.9ｇ、ロジ
ウム0.1ｇが担持されていた。
実施例 ５
実施例４と同様にして硝酸パラジウムを使用し
てパラジウム含有アルミナ粉体を調製した。次い
でこの粉体と酸化セリウムを加えてスラリーにし
て１当りアルミナ88ｇ、酸化セリウム12ｇ、お
よびパラジウム1.0ｇが担持された完成触媒を得
た。
比較例 １
実施例１と同様の方法で、硝酸セリウムのみを
除いて触媒を調製した。この触媒は１当りアル
ミナ80ｇ、パラジウム0.9ｇ、ロジウム0.1ｇが担
持されていた。
比較例 ２
実施例１と同様の方法で、塩化白金酸のみを用
いて、白金−アルミナ触媒を調製した。この触媒
は１当りアルミナ80ｇ、白金1.0ｇが担持され
ていた。
実施例 ６
実施例１〜５、比較例１〜２で得られた各触媒
について、次の様な方法でオゾンの分解率を求め
た。即ち、各触媒を各々長さ50mmになるように切
断し、ステンレス製反応管に充填し、オゾンを
200ppm含有する空気を線速0.8ｍ／secの流速
（空間速度 約57000hr-1）で触媒層に導入し、入
口温度20〜100℃におけるオゾン分解率を求めた。
得られた結果を表−１に示す。表−１より本発明
による触媒は、低温活性能およびオゾンの分解率
に優れていることがわかる。
<Industrial Application Field> The present invention relates to an ozone decomposition catalyst, particularly a catalyst for catalytically decomposing ozone contained in gas, and a method for producing the same. <Conventional technology and its problems> Ozone has strong oxidizing ability and becomes harmless oxygen when decomposed, so it is widely used in various fields for purposes such as deodorization, sterilization, bleaching, and reducing COD in wastewater. There is. However, some of the ozone used in the treatment is released into the atmosphere unreacted, which may cause secondary pollution such as photochemical smog. Furthermore, when an aircraft flies in the stratosphere, air containing ozone is introduced into the cabin, which poses a risk of adversely affecting passengers and crew. Furthermore, recently, ozone generation from devices that incorporate various high-voltage generators, such as dry-type copying machines, has become a problem.Since these devices are mainly placed indoors, the amount of ozone generated is small. Even if it is, the room will be contaminated. Ozone odor can be detected at concentrations below 1 ppm.
Concentrations of 2 ppm or higher cause irritation to the respiratory system and are harmful to the human body, so it is necessary to remove ozone emitted from various sources and render it harmless. Conventionally used waste ozone treatment techniques include an activated carbon method, a chemical cleaning method, and a thermal decomposition method.
The activated carbon method is used to treat low-concentration ozone, but as ozone decomposition progresses, the activated carbon is consumed and needs to be replenished, and when treating high-concentration ozone, the activated carbon itself is destroyed by the heat of reaction. There is a danger of ignition and combustion, which poses a problem in handling. The chemical cleaning method involves cleaning waste ozone with an aqueous solution of a reducing substance, resulting in high processing costs and problems in wastewater treatment. The thermal decomposition method requires heating to 300°C or higher in order to increase decomposition efficiency, and has drawbacks such as heating costs required to process a large amount of exhaust gas, which increases processing costs. On the other hand, in recent years, research has been conducted on the catalytic decomposition method as a waste ozone treatment method.This method is advantageous because it has no risk of ignition or explosion, does not require wastewater treatment, and can decompose and remove ozone at a low cost. has been done. Catalysts using oxides such as nickel, manganese, and cobalt are used as ozone decomposition catalysts (e.g.,
66347, JP-A No. 60-97049, etc.) and precious metal catalysts (e.g., JP-A-56-70823, JP-A-57-
122942, etc.), but each has low activity in the low temperature range from room temperature to 100°C, and has low decomposition efficiency as a practical catalyst and has durability problems, so it is difficult to use it in the low temperature range. There is a need to provide a catalyst that exhibits high activity and high durability. <Objective of the Invention> An object of the present invention is to provide an ozone decomposition catalyst that has excellent low-temperature activity and high durability when catalytically decomposing ozone contained in gas into oxygen. <Means for Solving the Problems> As a result of studying the problems in accordance with the above objectives, the present inventors found that at least one member selected from the group consisting of platinum, palladium, and rhodium is used in the fire-resistant three-dimensional structure. An ozone decomposition catalyst supported with a catalytically active material consisting of the elements of
The present inventors have discovered that it exhibits excellent ozone decomposition performance even at low temperatures of 0.degree. C., and is also excellent in durability, leading to the completion of the present invention. That is, while conventional noble metal catalysts use group non-noble metal oxides such as iron, cobalt, and nickel in combination, the catalyst of the present invention is characterized by using cerium oxide in combination with group non-noble metal oxides such as iron, cobalt, and nickel. at least one selected from
The reason is that it is used together with a seed element and is supported on a fire-resistant three-dimensional structure having an integral structure with excellent air permeability. In general, it is well known that cerium oxide is an oxide that is excellent at adsorbing and desorbing oxygen, especially since it is added to catalysts for the simultaneous removal of carbon monoxide, hydrocarbons, and nitrogen oxides from automobile exhaust gas. That's true. Cerium oxide, which has such characteristics, is excellent in adsorbing and decomposing ozone, and a catalyst containing at least one element selected from the group consisting of platinum, palladium, and rhodium and activated alumina is excellent in ozone decomposition. They discovered that it has excellent performance. The activated alumina used in the present invention is preferably used in powder form, and preferably has a specific surface area of 50 to 180 m 2 /g. Its crystal form is
Available forms are gamma, delta, theta, chi, katsupa, and eta. If necessary, activated alumina supported with 0.1 to 3% by weight of at least one of rare earth elements such as lanthanum, neodymium, and praseodymium or alkaline earth elements such as calcium and barium is also used to stabilize the activated alumina. It is possible. The starting materials for platinum used in the present invention include:
Chloroplatinic acid, dinitrodiammine platinum, etc. are used, and as the starting material for palladium, palladium nitrate, palladium chloride, palladium sulfite complex salt, palladium tetramine chloride, etc. are preferable. Preferred starting materials for rhodium include rhodium nitrate, rhodium chloride, rhodium sulfate, rhodium sulfite complex salts, and rhodium ammine complex salts. The total amount of at least one element selected from the group consisting of platinum, palladium and rhodium supported is in the range of 0.2 to 5 g, preferably 0.4 to 3 g per catalyst. Particularly preferred are those carrying palladium and rhodium in the above amounts. The starting material for cerium used in the present invention is preferably a water-soluble compound, such as cerium nitrate,
Cerium acetate is preferably used. In addition, water-insoluble cerium compounds such as cerium oxide, cerium carbonate, and cerium hydroxide are also used in combination with activated alumina. The amount of cerium used is 1 to 20 g as cerium oxide per catalyst, preferably 3 to 20 g per catalyst.
Used in the 10g range. The total amount of activated alumina, at least one element selected from the group consisting of platinum, palladium and rhodium, and cerium oxide is 30 to 300 g, preferably 60 to 170 g per catalyst. The refractory three-dimensional structure used in the present invention is preferably what is usually called a ceramic honeycomb carrier, particularly cordierite, mullite, α
- Honeycomb carriers made of alumina, zirconia, titania, titanium phosphate, aluminum titanate, petalite, spodiume, aluminosilicate, magnesium silicate, etc. are preferred, and cordierite is especially preferred. In addition, a unitary structure made of a heat-resistant metal with oxidation resistance, such as stainless steel or a Fe-Cr-Al alloy, is also used. The shape of the gas passage port (cell shape) may be hexagonal, quadrangular, triangular, or corrugated, and the cell density (number of cells/unit cross-sectional area) is 100 to 600 cells/square inch. If so, it is fully usable and gives good results. Other fire-resistant three-dimensional structures used in the present invention include alumina, alumina-silica,
Examples include inorganic fibrous carriers such as silica and titania, ceramic foams, and metal foams. The catalyst according to the present invention can be produced, for example, by the following method. (1) Mixing an aqueous solution of a water-soluble salt of at least one element selected from the group consisting of platinum, palladium, and rhodium and a water-soluble salt of cerium, impregnating and supporting activated alumina powder, and drying;
Calcination is performed in air at 300 to 800°C to immobilize platinum, palladium and/or rhodium and cerium on alumina in a water-insoluble form. Next, a slurry is prepared by adding dilute nitric acid water to this catalyst composition and wet-pulverizing it using a ball mill or the like. A finished catalyst is prepared by supporting the slurry on a refractory three-dimensional structure having an integral structure. (2) An aqueous solution of a water-soluble salt of at least one element selected from the group consisting of platinum, palladium, and rhodium is impregnated and supported on activated alumina, dried, and calcined in air at 300 to 800°C, and then deposited on the alumina. Fixing platinum, palladium and/or rhodium in water-insoluble form. Next, a predetermined amount of a water-insoluble cerium source is added thereto, dilute nitric acid water is added thereto, and the mixture is wet-pulverized using a ball mill or the like to prepare a slurry. A finished catalyst is prepared by supporting the slurry on a refractory three-dimensional structure having an integral structure. <Examples> The present invention will be explained in more detail below using Examples, but the present invention is not limited to these Examples. Example 1 1352 g of activated alumina with a specific surface area of 150 m 2 /g,
Palladium nitrate containing 16.7g palladium, 1.9
An aqueous solution of rhodium nitrate containing g of rhodium and cerium nitrate containing 106 g of cerium.
Soak 1285c.c., mix well for 30 minutes, and heat at 150℃ for 30 minutes.
After drying for an hour, it was calcined in air at 600°C for 2 hours to prepare alumina powder containing palladium, rhodium, and cerium. This powder was wet-milled with dilute nitric acid water in a ball mill for 20 hours to prepare a slurry. This slurry was immersed in a commercially available cordierite honeycomb carrier (manufactured by Nippon Insulators Co., Ltd.) for about 1 minute in a cylindrical carrier having an outer diameter of 93 mmφ and a length of 102 mm and having a cross section of 300 gas flow cells per square inch. Thereafter, the slurry was taken out, excess slurry in the cells was blown away with compressed air to remove clogging in all cells, and then dried at 130° C. for 3 hours to obtain a finished catalyst. This catalyst contains 73g of alumina, 7g of cerium oxide, 0.9g of palladium,
0.1g of rhodium was supported. Example 2 Platinum-, palladium-, and cerium-containing alumina powder was prepared in the same manner as in Example 1 using chloroplatinic acid, palladium nitrate, and cerium nitrate. Next, this powder is made into a slurry at a rate of 82
A finished catalyst was obtained in which 8 g of cerium oxide, 0.15 g of platinum and 0.85 g of palladium were supported. Example 3 Alumina powder containing platinum, rhodium, and cerium was prepared in the same manner as in Example 1 using chloroplatinic acid, rhodium nitrate, and cerium nitrate.
Next, this powder was made into a slurry, 90g per portion,
10g cerium oxide, 0.4g platinum and rhodium
A finished catalyst with 0.04 g supported was obtained. Example 4 1712 g of activated alumina with a specific surface area of 120 m 2 /g,
Palladium nitrate containing 16.2g palladium and 1.8
immersed in an aqueous solution of 1626 c.c. containing rhodium chloride containing g of rhodium, thoroughly mixed for 30 minutes, dried at 150°C for 3 hours, and then calcined in air at 650°C for 2 hours to produce palladium and rhodium-containing alumina. A powder was prepared. 270 g of cerium oxide was added to this powder, and the powder was wet-milled with dilute nitric acid water in a ball mill to prepare a slurry. This slurry was then supported on the same honeycomb carrier as in Example 1 to obtain a finished catalyst. This catalyst has 95 alumina per unit.
g, 15 g of cerium oxide, 0.9 g of palladium, and 0.1 g of rhodium were supported. Example 5 Palladium-containing alumina powder was prepared in the same manner as in Example 4 using palladium nitrate. Next, this powder and cerium oxide were added to form a slurry to obtain a finished catalyst in which 88 g of alumina, 12 g of cerium oxide, and 1.0 g of palladium were supported on each slurry. Comparative Example 1 A catalyst was prepared in the same manner as in Example 1 except for cerium nitrate. Each catalyst supported 80 g of alumina, 0.9 g of palladium, and 0.1 g of rhodium. Comparative Example 2 A platinum-alumina catalyst was prepared in the same manner as in Example 1 using only chloroplatinic acid. Each catalyst supported 80 g of alumina and 1.0 g of platinum. Example 6 For each catalyst obtained in Examples 1 to 5 and Comparative Examples 1 to 2, the ozone decomposition rate was determined by the following method. That is, each catalyst was cut to a length of 50 mm, filled in a stainless steel reaction tube, and ozone was added.
Air containing 200 ppm was introduced into the catalyst layer at a linear velocity of 0.8 m/sec (space velocity approximately 57000 hr -1 ), and the ozone decomposition rate at an inlet temperature of 20 to 100°C was determined.
The results obtained are shown in Table-1. Table 1 shows that the catalyst according to the present invention has excellent low-temperature activity and ozone decomposition rate.
【表】
実施例 ７
実施例１、２および４で得られた触媒につき、
次の100時間の耐久試験を行つた。即ち、実施例
６で使用した触媒に対しオゾンを100ppm含有す
る空気を線速0.5ｍ／secの流速（空間速度 約
35000hr-1）で、入口温度50℃で反応させた。得
られた結果を表−２に示す。表−２より本発明に
よる触媒は、100時間の耐久実験経過後もオゾン
分解率は反応初期と同じであり、耐久性の点でも
優れていることがわかる。[Table] Example 7 Regarding the catalysts obtained in Examples 1, 2 and 4,
The next 100 hour durability test was conducted. That is, air containing 100 ppm of ozone was applied to the catalyst used in Example 6 at a linear velocity of 0.5 m/sec (space velocity approx.
35000 hr -1 ) and an inlet temperature of 50°C. The results obtained are shown in Table-2. From Table 2, it can be seen that the catalyst according to the present invention has the same ozone decomposition rate as at the beginning of the reaction even after 100 hours of durability experiment, and is also excellent in terms of durability.
Claims (1)
よびロジウムからなる群から選択される少なくと
も１種の元素と酸化セリウムとからなる触媒活性
物質および活性アルミナとが担持せしめられてな
ることを特徴とするオゾン分解触媒。 ２ 白金、パラジウムおよびロジウムからなる群
から選択される少なくとも１種の元素の担持量が
触媒１当り0.2〜５ｇであり、酸化セリウムの
担持量が触媒１当り１〜20ｇであることを特徴
とする特許請求の範囲第１項記載の触媒。 ３ 触媒活性物質がパラジウム、ロジウムおよび
酸化セリウムであることを特徴とする特許請求の
範囲第１項記載の触媒。 ４ 耐火性三次元構造体がセラミツクハニカムで
あることを特徴とする特許請求の範囲第１項記載
の触媒。[Claims] 1. A catalytically active substance consisting of at least one element selected from the group consisting of platinum, palladium, and rhodium and cerium oxide and activated alumina are supported on a refractory three-dimensional structure. An ozone decomposition catalyst characterized by: 2. The supported amount of at least one element selected from the group consisting of platinum, palladium, and rhodium is 0.2 to 5 g per catalyst, and the supported amount of cerium oxide is 1 to 20 g per catalyst. A catalyst according to claim 1. 3. The catalyst according to claim 1, wherein the catalytically active substances are palladium, rhodium and cerium oxide. 4. The catalyst according to claim 1, wherein the refractory three-dimensional structure is a ceramic honeycomb.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61155036A JPS6312347A (en) | 1986-07-03 | 1986-07-03 | Ozone decomposing catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61155036A JPS6312347A (en) | 1986-07-03 | 1986-07-03 | Ozone decomposing catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6312347A JPS6312347A (en) | 1988-01-19 |
| JPH0550340B2 true JPH0550340B2 (en) | 1993-07-28 |
Family
ID=15597270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61155036A Granted JPS6312347A (en) | 1986-07-03 | 1986-07-03 | Ozone decomposing catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6312347A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013148693A (en) * | 2012-01-19 | 2013-08-01 | Ricoh Co Ltd | Corona charger and image forming apparatus |
-
1986
- 1986-07-03 JP JP61155036A patent/JPS6312347A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6312347A (en) | 1988-01-19 |
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