JP4498881B2 - Particulate combustion catalyst - Google Patents
Particulate combustion catalyst Download PDFInfo
- Publication number
- JP4498881B2 JP4498881B2 JP2004302016A JP2004302016A JP4498881B2 JP 4498881 B2 JP4498881 B2 JP 4498881B2 JP 2004302016 A JP2004302016 A JP 2004302016A JP 2004302016 A JP2004302016 A JP 2004302016A JP 4498881 B2 JP4498881 B2 JP 4498881B2
- Authority
- JP
- Japan
- Prior art keywords
- combustion catalyst
- catalyst
- palladium
- oxide
- combustion
- 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
- 239000003054 catalyst Substances 0.000 title claims description 76
- 238000002485 combustion reaction Methods 0.000 title claims description 60
- 229910003445 palladium oxide Inorganic materials 0.000 claims description 29
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 28
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 20
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 17
- 239000002245 particle Substances 0.000 claims description 16
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 14
- 229910000420 cerium oxide Inorganic materials 0.000 claims description 12
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 9
- 239000010936 titanium Substances 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- JQPTYAILLJKUCY-UHFFFAOYSA-N palladium(ii) oxide Chemical compound [O-2].[Pd+2] JQPTYAILLJKUCY-UHFFFAOYSA-N 0.000 claims 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 36
- HBEQXAKJSGXAIQ-UHFFFAOYSA-N oxopalladium Chemical compound [Pd]=O HBEQXAKJSGXAIQ-UHFFFAOYSA-N 0.000 description 29
- 230000003197 catalytic effect Effects 0.000 description 18
- 230000000694 effects Effects 0.000 description 15
- 238000007254 oxidation reaction Methods 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 238000002441 X-ray diffraction Methods 0.000 description 9
- 229910052763 palladium Inorganic materials 0.000 description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000007789 gas Substances 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 229920005992 thermoplastic resin Polymers 0.000 description 7
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 6
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 229930195733 hydrocarbon Natural products 0.000 description 5
- 150000002430 hydrocarbons Chemical class 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- PASHVRUKOFIRIK-UHFFFAOYSA-L calcium sulfate dihydrate Chemical compound O.O.[Ca+2].[O-]S([O-])(=O)=O PASHVRUKOFIRIK-UHFFFAOYSA-L 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 239000000446 fuel Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 241001391944 Commicarpus scandens Species 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 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 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- GPNDARIEYHPYAY-UHFFFAOYSA-N palladium(ii) nitrate Chemical compound [Pd+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O GPNDARIEYHPYAY-UHFFFAOYSA-N 0.000 description 2
- 239000013618 particulate matter Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 description 1
- ODPUKHWKHYKMRK-UHFFFAOYSA-N cerium;nitric acid Chemical compound [Ce].O[N+]([O-])=O ODPUKHWKHYKMRK-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 150000002013 dioxins Chemical class 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 239000011342 resin composition Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Images
Description
本発明は、低温で優れた触媒活性を発揮する燃焼触媒に関するものである。 The present invention relates to a combustion catalyst that exhibits excellent catalytic activity at low temperatures.
パラジウムや白金等の白金族元素を無機担体に担持した貴金属触媒は、白金族元素が酸化反応に優れた触媒活性を有していることを利用して、天然ガス等の燃料を効率的に燃焼させて発電を行うガスタービンやボイラ等の燃焼触媒として、或いは未燃の炭化水素や一酸化炭素を燃焼させる自動車等の排ガス浄化用触媒として利用されている（特許文献１−３等参照）。 Precious metal catalysts that carry platinum group elements such as palladium and platinum on an inorganic carrier efficiently burns fuel such as natural gas by utilizing the catalytic activity of platinum group elements with excellent oxidation reaction. It is used as a combustion catalyst for gas turbines and boilers that generate electric power, or as an exhaust gas purification catalyst for automobiles that burn unburned hydrocarbons or carbon monoxide (see Patent Documents 1-3).
一方、最近、パラジウム等の白金族元素を無機質担体に特定量担持させた微粒子状の燃焼促進剤を白金族元素の濃度が特定濃度になるように熱可塑性樹脂に配合することによって、色彩を害することがなく、しかも燃焼、焼却時に完全燃焼して、有害物の発生が抑制された熱可塑性樹脂組成物及びその成形体が提案されている（特許文献４−６参照）。 On the other hand, recently, by blending a particulate combustion accelerator in which a specific amount of a platinum group element such as palladium is supported on an inorganic carrier with a thermoplastic resin so that the concentration of the platinum group element becomes a specific concentration, the color is harmed. In addition, there has been proposed a thermoplastic resin composition that is completely burned during combustion and incineration, and suppresses the generation of harmful substances, and a molded product thereof (see Patent Documents 4-6).
そして、特に自動車の排ガス浄化触媒として使用する場合や、熱可塑性樹脂に配合して完全燃焼させる目的で使用する場合には、触媒活性が高いことはもとより、低温ででも高い触媒活性を発揮することが特に要求されている。例えば、ディーゼルエンジンから排出される微粒子状物質（ＰＭ）を除去する目的で使用する場合は、低速で市街地を走行する、すなわち排ガス温度が低い場合であっても燃焼触媒として十分な効果を発揮することが要求されているところであり、また、熱可塑性樹脂に配合して使用する場合には、焼却炉で通常の運転温度（比較的高温でする。）で焼却する場合よりはむしろ運転開始時のように炉内の温度が低い場合に燃焼触媒としての効果を発揮する燃焼触媒を提供することが望まれていた。 And especially when used as an exhaust gas purification catalyst for automobiles or when it is used for the purpose of complete combustion by blending with a thermoplastic resin, it should exhibit high catalytic activity at low temperatures as well as high catalytic activity. Is particularly required. For example, when it is used for the purpose of removing particulate matter (PM) discharged from a diesel engine, it travels in an urban area at a low speed, that is, exhibits a sufficient effect as a combustion catalyst even when the exhaust gas temperature is low. In addition, when blended with a thermoplastic resin, it is necessary to incinerate at the normal operating temperature (relatively high temperature) in an incinerator rather than at the start of operation. Thus, it has been desired to provide a combustion catalyst that exhibits an effect as a combustion catalyst when the temperature in the furnace is low.
本発明は、特に低温における燃焼触媒活性に優れた酸化パラジウムからなる活性成分をアルミナ粒子に担持させた燃焼触媒を提供することを目的とする。 An object of the present invention is to provide a combustion catalyst in which an active component made of palladium oxide having excellent combustion catalyst activity at a low temperature is supported on alumina particles.
本発明者等は鋭意検討した結果、酸化パラジウムと酸化セリウムに、さらに酸化チタンを触媒活性成分として使用した場合に上記目的を達成しうることを見いだし本発明に到った。 As a result of intensive studies, the present inventors have found that the above object can be achieved when palladium oxide and cerium oxide are used as a catalyst active component, and the present invention has been achieved.
すなわち、本発明は、
（１）χ−アルミナ粒子からなる担体に酸化パラジウム、酸化セリウム及び酸化チタンが担持されていることを特徴とする燃焼触媒。
（２）酸化パラジウムが金属パラジウム換算で０．０５〜１０ｗｔ％担持されていることを特徴とする（１）記載の燃焼触媒。
（３）酸化チタンが、アルミナ粒子に対して金属チタン換算で０．０１〜２０ｗｔ％担持されていることを特徴とする（１）又は（２）に記載の燃焼触媒を要旨とするものである。
That is, the present invention
(1) A combustion catalyst characterized in that palladium oxide, cerium oxide and titanium oxide are supported on a carrier composed of χ- alumina particles.
( 2 ) The combustion catalyst according to (1) , wherein 0.05 to 10 wt% of palladium oxide is supported in terms of metallic palladium.
( 3 ) The gist of the combustion catalyst according to (1) or (2) , wherein titanium oxide is supported on alumina particles in an amount of 0.01 to 20 wt% in terms of metallic titanium. .
本発明の燃焼触媒においては酸化チタン（ＴｉＯ２）を添加することによって酸化パラジウム（ＰｄＯ）の電子状態が低エネルギー側にシフトしＰｄ−Ｏの結合を切断しやすい状態にするという効果を発揮する。したがって、メタンが酸化パラジウム中の格子酸素と反応して金属パラジウム（Ｐｄ）が生成するメタン酸化反応が、アルミナ粒子に酸化パラジウムと酸化セリウムのみを担持させた燃焼触媒に比べて、酸化チタンを加えることでより低温で起こるようになるという効果を有している。 In the combustion catalyst of the present invention, by adding titanium oxide (TiO 2 ), the electronic state of palladium oxide (PdO) is shifted to a lower energy side, and the effect of making the bond of Pd—O easy to break is exhibited. . Therefore, the methane oxidation reaction in which methane reacts with lattice oxygen in palladium oxide to produce metallic palladium (Pd) adds titanium oxide as compared to a combustion catalyst in which only palladium oxide and cerium oxide are supported on alumina particles. This has the effect that it occurs at a lower temperature.
以下に、本発明を詳細に説明する。
本発明の燃焼触媒は、アルミナ粒子からなる担体に酸化パラジウム、酸化セリウム及び酸化チタンを担持させたものである。
アルミナ粒子としては従来から触媒担体として使用されているα−アルミナ、γ−アルミナ等が特に制限なく使用できるが、特に、極めて細かい水酸化アルミニウム（ギプサイト）を３００℃以上、約８００℃以下の温度で加熱することにより生成するχ−アルミナを使用するのが好ましい。一方、この際の加熱温度が８００℃を超えるとκ−アルミナを経て安定なα−アルミナとなる。また、χ−アルミナを生成するためには水酸化アルミニウムの粒子径が極めて細かいことが必要であり、具体的には平均粒子径が５０μｍ以下、好ましくは２０μｍ以下、特に粒子径が０．２〜１０．０μｍ程度のものを使用するのが最も好ましい。
The present invention is described in detail below.
The combustion catalyst of the present invention is obtained by supporting palladium oxide, cerium oxide and titanium oxide on a carrier made of alumina particles.
As the alumina particles, α-alumina, γ-alumina and the like conventionally used as a catalyst carrier can be used without any particular limitation. In particular, extremely fine aluminum hydroxide (gypsite) is used at a temperature of 300 ° C. or more and about 800 ° C. or less. It is preferred to use χ-alumina produced by heating at On the other hand, when the heating temperature at this time exceeds 800 ° C., it becomes stable α-alumina via κ-alumina. In order to produce χ-alumina, it is necessary that the particle size of aluminum hydroxide is extremely fine. Specifically, the average particle size is 50 μm or less, preferably 20 μm or less, and particularly the particle size is 0.2 to It is most preferable to use a material having a size of about 10.0 μm.
次いで、本発明においては上記アルミナ粒子には酸化パラジウム（ＰｄＯ）、酸化セリウム（ＣｅＯ２）及び酸化チタン（ＴｉＯ２）を担持させる。
酸化パラジウムは従来から燃焼触媒の活性成分としてよく知られており、触媒表面に酸素が解離吸着したＰｄ−Ｏの酸化状態で炭化水素類を酸化し、酸化パラジウム自身は還元されて金属（Ｐｄ）となり、金属（Ｐｄ）は再び酸化されてＰｄ−Ｏの酸化物状態を生成し、これを繰り返して炭化水素類を酸化する機構であるとされている。
Next, in the present invention, the alumina particles carry palladium oxide (PdO), cerium oxide (CeO 2 ), and titanium oxide (TiO 2 ).
Palladium oxide has been well known as an active component of combustion catalysts, and it oxidizes hydrocarbons in the oxidized state of Pd-O in which oxygen is dissociated and adsorbed on the catalyst surface, and the palladium oxide itself is reduced to metal (Pd). Thus, the metal (Pd) is oxidized again to generate an oxide state of Pd—O, and this is repeated to oxidize hydrocarbons.
更に、本発明においては燃焼触媒としての触媒活性を向上させる目的で酸化セリウム（ＣｅＯ２）を使用するのが好ましい。酸化セリウムを酸化パラジウム触媒に添加することにより、酸化パラジウムの格子中に積層欠陥が生じ、酸化パラジウムの格子酸素が脱離しやすい状態になり、低温における触媒活性が高くなるという効果を有している。また、アルミナ担体上に担持した酸化パラジウム触媒に酸化セリウムを共存させると、担体であるアルミナの焼結を防ぐ効果も有している（非特許文献１）ので、担体の焼結による比表面積の減少を抑制し、触媒活性が燃焼時に低下することを防止することができる。 Furthermore, in the present invention, it is preferable to use cerium oxide (CeO 2 ) for the purpose of improving the catalytic activity as a combustion catalyst. By adding cerium oxide to the palladium oxide catalyst, stacking faults are generated in the palladium oxide lattice, and the lattice oxygen of the palladium oxide is easily released, and the catalytic activity at low temperatures is increased. . Further, coexistence of cerium oxide in the palladium oxide catalyst supported on the alumina carrier also has an effect of preventing sintering of alumina as a carrier (Non-patent Document 1). Reduction can be suppressed and catalyst activity can be prevented from decreasing during combustion.
また、酸化チタン（ＴｉＯ２）はｎ型半導体であるため、マイナスの電荷を持った電子がパラジウムを引き付け、酸化パラジウム中のパラジウムと酸素の結合を、切断しやすい状態にする作用を有しているのでより低温で燃焼触媒としての効果を発揮させるという機能を有している。 In addition, since titanium oxide (TiO 2 ) is an n-type semiconductor, it has the function of attracting palladium by negatively charged electrons and making the bond between palladium and oxygen in palladium oxide easy to break. Therefore, it has a function of exhibiting the effect as a combustion catalyst at a lower temperature.
本発明は、アルミナ粒子からなる担体に上述した酸化パラジウム、酸化セリウム及び酸化チタンを担持するのであるが、その際、酸化パラジウムの担持量が触媒担体に対する金属パラジウム換算で０．０５〜１０ｗｔ％となるようにするのが好ましい。また、酸化セリウムの好ましい担持量は金属セリウム換算で０．０１〜３０ｗｔ％である。更にまた、酸化チタンの担持量はアルミナ粒子に対して金属チタン換算で０．０１〜２０ｗｔ％とするのが好ましい。特に、酸化チタンの担持量が０．０１〜２．０ｗｔ％にした場合は、触媒活性発現温度（常圧固定床流通式反応装置を使用したメタン酸化反応において転化率が２０％となる温度）はさほど低下しないものの、燃焼触媒としての有効使用温度（同メタン酸化反応において転化率が５０％となる温度）を低下させることが可能となる。一方、酸化チタンの担持量が２ｗｔ％を超えると徐々に触媒活性発現温度が低下して、例えば、２５０℃の低温ででも２０％程度の転化率を示すようになる。 In the present invention, the above-described palladium oxide, cerium oxide, and titanium oxide are supported on a support made of alumina particles. At this time, the supported amount of palladium oxide is 0.05 to 10 wt% in terms of metal palladium with respect to the catalyst support. It is preferable to do so. Moreover, the preferable load of cerium oxide is 0.01-30 wt% in conversion of metal cerium. Furthermore, the supported amount of titanium oxide is preferably 0.01 to 20 wt% in terms of titanium metal with respect to the alumina particles. In particular, when the supported amount of titanium oxide is 0.01 to 2.0 wt%, the catalyst activity expression temperature (the temperature at which the conversion rate becomes 20% in the methane oxidation reaction using an atmospheric pressure fixed bed flow type reactor) Although not so much reduced, it is possible to reduce the effective use temperature as a combustion catalyst (temperature at which the conversion rate becomes 50% in the methane oxidation reaction). On the other hand, when the supported amount of titanium oxide exceeds 2 wt%, the catalyst activity expression temperature gradually decreases, and for example, a conversion rate of about 20% is exhibited even at a low temperature of 250 ° C.
本発明の燃焼触媒の製造方法としては、例えば、メタノール中にチタンテトライソプロポキサイド（Ｔｉ（ｉ−ＯＣ３Ｈ７）４）を溶解して水酸化アルミニウム（ギプサイト）粉末を加えて攪拌し、しかる後に１２０℃で一晩乾燥させた。次いで、脱イオン水に先に乾燥させた乾燥物及び硝酸セリウム（Ｃｅ（ＮＯ３）３）を加え攪拌した後に硝酸パラジウム（Ｐｄ（ＮＯ３）２を加え攪拌した後、１２０℃で一晩乾燥させ、５００℃で焼成することにより本発明の燃焼触媒を調製することができる。 As a method for producing the combustion catalyst of the present invention, for example, titanium tetraisopropoxide (Ti (i-OC 3 H 7 ) 4 ) is dissolved in methanol, and aluminum hydroxide (gypsite) powder is added and stirred. Thereafter, it was dried at 120 ° C. overnight. Next, the dried product previously dried in deionized water and cerium nitrate (Ce (NO 3 ) 3 ) were added and stirred, then palladium nitrate (Pd (NO 3 ) 2 was added and stirred, and then dried at 120 ° C. overnight. The combustion catalyst of the present invention can be prepared by calcining at 500 ° C.
また、本発明の燃焼触媒の粒径は、平均粒子径が５０μｍ以下、好ましくは０．１〜２０μｍ、特に好ましくは０．２〜１０μｍである。また、本発明の燃焼触媒の比表面積は１００ｍ２／ｇ以上、好ましくは１５０ｍ２／ｇ以上である。比表面積は燃焼触媒としての触媒活性を左右する要素であり、比表面積が１００ｍ２／ｇ未満では十分な触媒活性がなく、結果的に多量の触媒を必要とするので好ましくない。 The particle diameter of the combustion catalyst of the present invention is 50 μm or less, preferably 0.1 to 20 μm, particularly preferably 0.2 to 10 μm. The specific surface area of the combustion catalyst of the present invention is 100 m 2 / g or more, preferably 150 m 2 / g or more. The specific surface area is an element that influences the catalytic activity as a combustion catalyst. If the specific surface area is less than 100 m 2 / g, there is no sufficient catalytic activity, and as a result, a large amount of catalyst is required, which is not preferable.
以下に、本発明を実施例に基づいて具体的に説明する。
なお、燃焼触媒の触媒活性は、常圧固定床流通式反応装置を用いたメタン酸化に対する活性試験を行って測定した。測定方法は、燃焼触媒０．５ｇを内径８．５ｍｍの石英製反応器に入れ、メタン（ＣＨ４）と酸素の分圧がそれぞれ３．４ｋＰａ及び２０．３ｋＰａと酸素過剰になるようヘリウム（Ｈｅ）で希釈した混合気を反応気体として流して所定温度条件下で生成する二酸化炭素及び水をオンライン式ガスクロマトグラフ（島津製作所製ＧＣ−８ＡＰＴ、積分器Ｃ−６ＴＡ）によってＴＣＤで検出して測定した。
また、触媒活性を表すメタン転化率（ＣＭ（％））は下記式にしたがって計算した。
ＣＭ＝１００ＣＯ２（Ｐ）／［ＣＨ４（Ｐ）＋ＣＯ２（Ｐ）］
ここでＣＨ４（Ｐ）及びＣＯ２（Ｐ）はそれぞれ反応容器出口で測定したメタン及び二酸化炭素のモル数である。
The present invention will be specifically described below based on examples.
The catalytic activity of the combustion catalyst was measured by conducting an activity test for methane oxidation using an atmospheric pressure fixed bed flow reactor. In the measurement method, 0.5 g of the combustion catalyst was put into a quartz reactor having an inner diameter of 8.5 mm, and helium (He was added so that the partial pressures of methane (CH 4 ) and oxygen were 3.4 kPa and 20.3 kPa, respectively, so that the oxygen was excessive. Carbon dioxide and water produced under a predetermined temperature condition by flowing the air-fuel mixture diluted in (1) as a reaction gas, and detected by TCD using an on-line gas chromatograph (Shimadzu GC-8APT, integrator C-6TA). .
Moreover, the methane conversion rate (C M (%)) representing the catalytic activity was calculated according to the following formula.
C M = 100 CO 2 (P) / [CH 4 (P) + CO 2 (P)]
Here, CH 4 (P) and CO 2 (P) are the number of moles of methane and carbon dioxide measured at the outlet of the reaction vessel, respectively.
本発明の燃焼触媒の低温における触媒活性の評価は、上記方法で測定した転化率が２０％となる温度（触媒活性発現温度）と転化率が５０％となる温度（有効使用温度）で行った。すなわち、触媒活性発現温度は触媒効果を発揮し始める温度を概略意味していて、この温度が低ければ低いほど低温でも燃焼触媒としての機能を発揮する。一方、有効使用温度は、当該燃焼触媒を使用して転化率が５０％となる温度、すなわち実用上十分な触媒活性を発揮する温度を意味している。 Evaluation of the catalytic activity of the combustion catalyst of the present invention at a low temperature was carried out at a temperature at which the conversion rate measured by the above method was 20% (catalytic activity expression temperature) and a temperature at which the conversion rate was 50% (effective use temperature). . That is, the catalyst activity expression temperature generally means the temperature at which the catalytic effect starts to be exhibited, and the lower this temperature, the more the function as a combustion catalyst is exhibited even at a lower temperature. On the other hand, the effective use temperature means a temperature at which the conversion rate becomes 50% using the combustion catalyst, that is, a temperature at which practically sufficient catalytic activity is exhibited.
更に、本発明の燃焼触媒中のパラジウムからなる活性成分が上記試験に供した際に触媒として作用したことをＸ線回折によってＰｄ−Ｏ（酸化パラジウム）の状態からＰｄ（金属パラジウム）の状態に変わることで観察した。 Further, the fact that the active component comprising palladium in the combustion catalyst of the present invention acted as a catalyst when subjected to the above test was changed from a Pd—O (palladium oxide) state to a Pd (metal palladium) state by X-ray diffraction. Observed by changing.
実施例１〜５
所定量のチタンテトライソプロポキサイド（Ｔｉ（ｉ−ＯＣ３Ｈ７）４）を溶解したメタノール中に平均粒径１．０μｍの水酸化アルミニウム（ギプサイト）を所定量添加して１時間攪拌した後、１２０℃で一晩乾燥した。次いで、脱イオン水中に前記乾燥物と硝酸セリウムを所定量加えて３０分間攪拌した後、硝酸パラジウムを所定量加えて更に１時間攪拌し、しかる後に１２０℃で一晩乾燥させ、５００℃で１時間焼成して表１に示す燃焼触媒（Ａ〜Ｅ）を得た。なお、Ｘ線回折を測定した結果、燃焼触媒の担体はχ−アルミナであることが確認された。
上記実施例１〜５の燃焼触媒（Ａ〜Ｅ）についてメタン酸化反応による触媒活性を測定した。結果を同じく表１に示す。
Examples 1-5
After adding a predetermined amount of aluminum hydroxide (gypsite) having an average particle diameter of 1.0 μm in methanol in which a predetermined amount of titanium tetraisopropoxide (Ti (i-OC 3 H 7 ) 4 ) is dissolved, the mixture is stirred for 1 hour. And dried at 120 ° C. overnight. Next, after adding a predetermined amount of the dried product and cerium nitrate in deionized water and stirring for 30 minutes, a predetermined amount of palladium nitrate was added and further stirred for 1 hour, and then dried at 120 ° C. overnight, followed by 1 at 500 ° C. The combustion catalyst (AE) shown in Table 1 was obtained by calcining for hours. As a result of measuring X-ray diffraction, it was confirmed that the carrier of the combustion catalyst was χ-alumina.
About the combustion catalyst (AE) of the said Examples 1-5, the catalyst activity by a methane oxidation reaction was measured. The results are also shown in Table 1.
比較例１〜３
また、比較のために酸化チタンを使用しない以外は実施例１と同様にした比較例１（Ｆ）、同じく酸化チタンを使用しない以外は実施例３と同様にした比較例２（Ｇ）、及び酸化セリウムを使用しない以外は実施例１と同様にした比較例３（Ｈ）を得た。結果を同じく表１に示す。
また、比較例１〜３についても同様にメタン酸化反応による触媒活性を測定した。結果を同じく表１に示す。
Comparative Examples 1-3
For comparison, Comparative Example 1 (F) which is the same as Example 1 except that no titanium oxide is used, Comparative Example 2 (G) which is the same as Example 3 except that no titanium oxide is used, and Comparative Example 3 (H) was obtained in the same manner as in Example 1 except that cerium oxide was not used. The results are also shown in Table 1.
Moreover, the catalyst activity by methane oxidation reaction was similarly measured about Comparative Examples 1-3. The results are also shown in Table 1.
表１
表１からも明らかなように本発明の実施例１〜５にかかる燃焼触媒（Ａ〜Ｅ）は比較例にかかる燃焼触媒（Ｆ〜Ｇ）に比べて触媒活性発現温度が１４℃〜１２０℃も低く、本発明の燃焼触媒が極めて低温度から触媒機能を発現することがわかる。また、有効使用温度も概ね比較例の燃焼触媒に比べて低く、特に実施例１（Ａ）、４（Ｄ）の燃焼触媒は比較例の燃焼触媒に比べて２０℃以上低温ででも十分な触媒活性を発揮することがわかった。 As is clear from Table 1, the combustion catalyst (AE) according to Examples 1 to 5 of the present invention has a catalyst activity expression temperature of 14 ° C. to 120 ° C. as compared with the combustion catalyst (F to G) according to the comparative example. It can be seen that the combustion catalyst of the present invention exhibits a catalytic function from an extremely low temperature. Further, the effective use temperature is generally lower than that of the combustion catalyst of the comparative example, and in particular, the combustion catalysts of Examples 1 (A) and 4 (D) are sufficient even at a temperature of 20 ° C. or more lower than the combustion catalyst of the comparative example. It was found to be active.
更にまた、実施例１（Ａ）、実施例２（Ｂ）、比較例１（Ｆ）、比較例２（Ｇ）の燃焼触媒について使用前（フレッシュ時）のＸ線回折図を図１に、２００℃にてメタン酸化反応を行った後のＸ線回折図を図２に、同じく３００℃にてメタン酸化反応を行った後のＸ線回折図を図３に示す。
図１からも明らかなように使用前の燃焼触媒Ａ、Ｂ、Ｆ、ＧにはＰｄＯ（酸化パラジウム）の（１０１面及び１１０面）に基づくピークがみられるとともに、燃焼触媒Ｂについては酸化チタンの１０１面に基づくピークも観察される。これは、燃焼触媒Ｂが他の燃焼触媒に比べて多量の酸化チタンを添加していることによるものと考えられる。
また、２００℃におけるメタン酸化反応では図２のＸ線回折図からも明らかなように、あまり反応は進行していない、すなわち、燃焼触媒の変化も起こっていないことがわかる。
Furthermore, FIG. 1 shows an X-ray diffraction diagram of the combustion catalysts of Example 1 (A), Example 2 (B), Comparative Example 1 (F), and Comparative Example 2 (G) before use (when fresh). FIG. 2 shows the X-ray diffraction diagram after the methane oxidation reaction at 200 ° C., and FIG. 3 shows the X-ray diffraction diagram after the methane oxidation reaction at 300 ° C.
As is clear from FIG. 1, the combustion catalysts A, B, F, and G before use have peaks based on PdO (palladium oxide) (101 plane and 110 plane), and the combustion catalyst B has titanium oxide. A peak based on the 101 plane is also observed. This is considered to be due to the fact that the combustion catalyst B adds a larger amount of titanium oxide than the other combustion catalysts.
Further, as is apparent from the X-ray diffraction diagram of FIG. 2, in the methane oxidation reaction at 200 ° C., it can be seen that the reaction does not proceed so much, that is, the combustion catalyst does not change.
一方、３００℃でメタン酸化反応を行った場合は、図３からも明らかなように、ＰｄＯ（酸化パラジウム）に基づくピークが消失してＰａ（パラジウム金属）の（１１１面及び２００面）に基づくピークが出現している。このことから、本発明の燃焼触媒が触媒表面に酸素が解離吸着したＰｄ−Ｏの酸化状態で炭化水素類を酸化し、酸化パラジウム自身は還元されて金属（Ｐｄ）ことで触媒活性を発揮することがわかる。更に、図３からも明らかなように燃焼触媒Ｆに比べて本発明の燃焼触媒Ａ、Ｂは結晶性が低く触媒活性が高いことがわかる。 On the other hand, when the methane oxidation reaction is performed at 300 ° C., as is clear from FIG. 3, the peak based on PdO (palladium oxide) disappears and is based on (111 plane and 200 plane) of Pa (palladium metal). A peak appears. From this, the combustion catalyst of the present invention oxidizes hydrocarbons in the oxidized state of Pd-O in which oxygen is dissociated and adsorbed on the catalyst surface, and palladium oxide itself is reduced and exhibits catalytic activity by being metal (Pd). I understand that. Further, as apparent from FIG. 3, it can be seen that the combustion catalysts A and B of the present invention have lower crystallinity and higher catalytic activity than the combustion catalyst F.
本発明の燃焼触媒は、従来公知のパラジウム系燃焼触媒に比べると極めて低温度からでも触媒活性を発揮するので天然ガス等の燃料を効率的に燃焼させて発電を行うガスタービンやボイラ等の燃焼触媒や、或いは未燃の炭化水素や一酸化炭素を燃焼させる自動車等の排ガス浄化用触媒として極めて有効である。更に、本発明の燃焼触媒を熱可塑性樹脂中に極微量（金属パラジウム換算で０．１〜１００ｐｐｍ、好ましくは０．３〜５０ｐｐｍ、より好ましくは０．５〜２０ｐｐｍ）配合することで熱可塑性樹脂組成物、或いはそれを成形して得られるフィルム、シート或いは各種成形品などの成形体を燃焼、焼却する際に、完全燃焼させることができ、また、一酸化炭素やダイオキシン類等の有害物の発生を抑制することができる。 The combustion catalyst of the present invention exhibits catalytic activity even at a very low temperature as compared with conventionally known palladium-based combustion catalysts, so that combustion such as gas turbines and boilers that generate electricity by efficiently burning fuel such as natural gas, etc. It is extremely effective as a catalyst or an exhaust gas purifying catalyst for automobiles that burn unburned hydrocarbons and carbon monoxide. Furthermore, the thermoplastic resin is blended in the thermoplastic resin in a trace amount (0.1 to 100 ppm, preferably 0.3 to 50 ppm, more preferably 0.5 to 20 ppm in terms of metallic palladium) in the thermoplastic resin. When combusting or incinerating a composition, or a molded product such as a film, sheet or various molded products obtained by molding the composition, it can be completely burned, and harmful substances such as carbon monoxide and dioxins Occurrence can be suppressed.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004302016A JP4498881B2 (en) | 2004-10-15 | 2004-10-15 | Particulate combustion catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004302016A JP4498881B2 (en) | 2004-10-15 | 2004-10-15 | Particulate combustion catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2006110497A JP2006110497A (en) | 2006-04-27 |
| JP4498881B2 true JP4498881B2 (en) | 2010-07-07 |
Family
ID=36379449
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004302016A Expired - Fee Related JP4498881B2 (en) | 2004-10-15 | 2004-10-15 | Particulate combustion catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4498881B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5228144B2 (en) * | 2011-01-17 | 2013-07-03 | 綾子 佐藤 | Low temperature combustion analysis and measurement system using metal catalyst effect |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55134641A (en) * | 1979-04-09 | 1980-10-20 | Mitsubishi Heavy Ind Ltd | Oxidation catalyst |
| JPS5830338A (en) * | 1981-08-18 | 1983-02-22 | Toyota Motor Corp | Waste gas purifying catalyst |
| JPS59160536A (en) * | 1983-03-04 | 1984-09-11 | Hitachi Ltd | Combustion-catalyst and its manufacture |
| JPS61230737A (en) * | 1985-04-05 | 1986-10-15 | Matsushita Electric Ind Co Ltd | Noble metal supported catalyst for purifying exhaust gas |
| JPH03169342A (en) * | 1989-11-22 | 1991-07-23 | Ford Motor Co | Three-way catalyst for automotive exhaust substance control |
| JPH08206506A (en) * | 1994-11-15 | 1996-08-13 | Inst Fr Petrole | Combusting catalyst and combusting method using the catalyst |
| JP2003253142A (en) * | 2002-03-04 | 2003-09-10 | Okura Ind Co Ltd | Thermoplastic resin composition and its molded product |
-
2004
- 2004-10-15 JP JP2004302016A patent/JP4498881B2/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55134641A (en) * | 1979-04-09 | 1980-10-20 | Mitsubishi Heavy Ind Ltd | Oxidation catalyst |
| JPS5830338A (en) * | 1981-08-18 | 1983-02-22 | Toyota Motor Corp | Waste gas purifying catalyst |
| JPS59160536A (en) * | 1983-03-04 | 1984-09-11 | Hitachi Ltd | Combustion-catalyst and its manufacture |
| JPS61230737A (en) * | 1985-04-05 | 1986-10-15 | Matsushita Electric Ind Co Ltd | Noble metal supported catalyst for purifying exhaust gas |
| JPH03169342A (en) * | 1989-11-22 | 1991-07-23 | Ford Motor Co | Three-way catalyst for automotive exhaust substance control |
| JPH08206506A (en) * | 1994-11-15 | 1996-08-13 | Inst Fr Petrole | Combusting catalyst and combusting method using the catalyst |
| JP2003253142A (en) * | 2002-03-04 | 2003-09-10 | Okura Ind Co Ltd | Thermoplastic resin composition and its molded product |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006110497A (en) | 2006-04-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5414786B2 (en) | Catalytic treatment with hydrogen for control of NOx emissions | |
| US7976784B2 (en) | Methods and systems including CO oxidation catalyst with low NO to NO2 conversion | |
| JP6005251B2 (en) | Method for producing CO shift catalyst and method for purifying gasification gas | |
| KR20110033045A (en) | Process and catalyst system for scr of nox | |
| KR100370903B1 (en) | Method for Treating by Combustion Carbon-Containing Particles in an Internal Combustion Engine Exhaust Circuit | |
| JP2007014873A (en) | Apparatus for removing particle substance | |
| KR20150021055A (en) | Catalyst composition | |
| JP2021514837A (en) | Gasoline engine exhaust gas aftertreatment catalyst | |
| JP4498881B2 (en) | Particulate combustion catalyst | |
| Herbst et al. | Challenges in applied oxidation catalysis | |
| JPH06506871A (en) | Combustion catalyst containing binary oxide and method of use as described above | |
| US8236261B2 (en) | Exhaust system having a gold-platinum group metal catalyst | |
| JP2007239616A (en) | Exhaust emission control device, exhaust emission control method, and purification catalyst | |
| JP2006226218A (en) | Exhaust emission control device and exhaust emission control method | |
| JP2010184202A (en) | Catalyst for generating hydrogen and method for producing the catalyst | |
| JP2015054261A (en) | Catalyst for co oxidation and method for co oxidation | |
| JP2009279579A (en) | Oxidation catalyst | |
| JP5585805B2 (en) | PM oxidation catalyst and production method thereof | |
| JP2009138591A (en) | Exhaust emission control device, exhaust emission control method, and nox emission control catalyst of thermal engine | |
| EP0555936A1 (en) | Process for the reduction of nitrogen oxides to nitrogen | |
| JPWO2014103076A1 (en) | CO shift catalyst, CO shift reaction apparatus, and purification method of gasification gas | |
| WO2014115573A1 (en) | Catalyst for oxidation of nitrogen oxides, and method for oxidation of nitrogen oxides | |
| JPH06126173A (en) | Catalyst device for cleaning exhaust gas from natural gas engine | |
| JP2005218976A (en) | Emission gas purification catalyst and its producing method | |
| JP2017080678A (en) | Removal method of unburned component in exhaust gas, and removal method of nitrogen oxide in exhaust gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070921 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100125 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100208 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100215 |
|
| 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: 20100329 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100414 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130423 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130423 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140423 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |