JP6444289B2 - Catalyst that can be activated by electric field application, and steam reforming method using the catalyst - Google Patents
Catalyst that can be activated by electric field application, and steam reforming method using the catalyst Download PDFInfo
- Publication number
- JP6444289B2 JP6444289B2 JP2015215720A JP2015215720A JP6444289B2 JP 6444289 B2 JP6444289 B2 JP 6444289B2 JP 2015215720 A JP2015215720 A JP 2015215720A JP 2015215720 A JP2015215720 A JP 2015215720A JP 6444289 B2 JP6444289 B2 JP 6444289B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst
- steam reforming
- electric field
- reaction
- particles
- 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.)
- Active
Links
- 239000003054 catalyst Substances 0.000 title claims description 244
- 230000005684 electric field Effects 0.000 title claims description 46
- 238000000629 steam reforming Methods 0.000 title claims description 25
- 238000000034 method Methods 0.000 title claims description 14
- 239000002245 particle Substances 0.000 claims description 85
- 238000006243 chemical reaction Methods 0.000 claims description 38
- 229910052751 metal Inorganic materials 0.000 claims description 35
- 239000002184 metal Substances 0.000 claims description 35
- 239000000919 ceramic Substances 0.000 claims description 29
- 150000002500 ions Chemical class 0.000 claims description 20
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims description 13
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims description 13
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 10
- 238000005245 sintering Methods 0.000 claims description 10
- 239000010948 rhodium Substances 0.000 claims description 8
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Substances [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 6
- 229910052697 platinum Inorganic materials 0.000 claims description 6
- 239000004215 Carbon black (E152) Substances 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 5
- 229930195733 hydrocarbon Natural products 0.000 claims description 5
- 150000002430 hydrocarbons Chemical class 0.000 claims description 5
- 239000001257 hydrogen Substances 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- 229910052703 rhodium Inorganic materials 0.000 claims description 5
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 4
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 3
- 239000007789 gas Substances 0.000 claims description 3
- 229910052763 palladium Inorganic materials 0.000 claims description 3
- 229910052707 ruthenium Inorganic materials 0.000 claims description 3
- 229910000416 bismuth oxide Inorganic materials 0.000 claims description 2
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 claims description 2
- 229910052737 gold Inorganic materials 0.000 claims description 2
- 239000010931 gold Substances 0.000 claims description 2
- 239000011810 insulating material Substances 0.000 claims description 2
- 229910052741 iridium Inorganic materials 0.000 claims description 2
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 2
- 229910052742 iron Inorganic materials 0.000 claims 1
- 230000000694 effects Effects 0.000 description 20
- 238000010304 firing Methods 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 12
- 230000003197 catalytic effect Effects 0.000 description 10
- 238000001035 drying Methods 0.000 description 10
- 238000002844 melting Methods 0.000 description 10
- 230000008018 melting Effects 0.000 description 10
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 10
- 238000012360 testing method Methods 0.000 description 9
- 238000006555 catalytic reaction Methods 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000001354 calcination Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 150000002736 metal compounds Chemical class 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000003628 erosive effect Effects 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 239000000470 constituent Substances 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 238000005457 optimization Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000012495 reaction gas Substances 0.000 description 3
- 230000003213 activating effect Effects 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 229910052878 cordierite Inorganic materials 0.000 description 2
- 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 2
- 230000005611 electricity Effects 0.000 description 2
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 238000004438 BET method Methods 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- 241000196324 Embryophyta Species 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 229910052777 Praseodymium Inorganic materials 0.000 description 1
- 241000705939 Shortia uniflora Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000012876 carrier material Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000009792 diffusion process Methods 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
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000010411 electrocatalyst Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229910052809 inorganic oxide Inorganic materials 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000011533 mixed conductor Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- -1 oxygen ion Chemical class 0.000 description 1
- MMKQUGHLEMYQSG-UHFFFAOYSA-N oxygen(2-);praseodymium(3+) Chemical compound [O-2].[O-2].[O-2].[Pr+3].[Pr+3] MMKQUGHLEMYQSG-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
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 description 1
- 229910003447 praseodymium oxide Inorganic materials 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 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 1
- 239000011163 secondary particle Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 229910001928 zirconium oxide Inorganic materials 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Description
本発明は、触媒に関し、詳しくは、反応効率向上の一手段として電場を印加させて活性向上を図ることのできる電場触媒に関する。 The present invention relates to a catalyst, and more particularly, to an electric field catalyst capable of improving activity by applying an electric field as one means for improving reaction efficiency.
触媒は、化学反応を扱うあらゆる分野で使用されており、ケミカルプラントのような大型工場から、自動車等の移動体、更には、家庭用発電機等の民生機器においても使用されている。触媒の利用に際しては、外部からエネルギーを印加して触媒を活性化するのが一般的である。そして、この印加エネルギーとしては、ほとんどの場合が熱エネルギーであり、バーナー・ヒータ等による加熱や、通電による抵抗加熱等によるものが多い。 Catalysts are used in all fields dealing with chemical reactions, and are also used in large-scale factories such as chemical plants, mobile objects such as automobiles, and consumer equipment such as household generators. When using the catalyst, it is common to activate the catalyst by applying energy from the outside. In most cases, the applied energy is thermal energy, and is often due to heating by a burner / heater or resistance heating by energization.
熱エネルギー印加による触媒の活性化の際に必要となる熱量（加熱温度）は、触媒反応の種類により、３００℃程度の比較的低温で済む場合もあるが、５００〜６００℃以上の高温が要求される場合も多い。そのため、エネルギー効率の向上、高温加熱が忌避されるような環境での使用を考慮し、触媒分野では活性温度の低下の研究開発が盛んになされている。 The amount of heat (heating temperature) required for activating the catalyst by applying thermal energy may be a relatively low temperature of about 300 ° C. depending on the type of catalytic reaction, but a high temperature of 500 to 600 ° C. or more is required. There are many cases. For this reason, research and development for reducing the active temperature has been actively conducted in the catalyst field in consideration of use in an environment where improvement in energy efficiency and high-temperature heating are avoided.
ここで、近年、触媒の活性化のためのエネルギー印加の手法として、電場エネルギーを触媒に印加する技術が報告されている（以下、本発明の対象となる、電場エネルギーを印加することを前提とする触媒を「電場触媒」と称するときがある。）。例えば、特許文献１では、炭化水素と水蒸気とを反応させる反応（水蒸気改質反応）により水素製造する装置について、触媒に一定条件で電場を印加する技術が記載されている。 Here, in recent years, a technique for applying electric field energy to a catalyst has been reported as an energy application method for activating the catalyst (hereinafter, based on the premise that electric field energy is applied, which is an object of the present invention). The catalyst that does this is sometimes referred to as an “electric field catalyst”). For example, Patent Document 1 describes a technique for applying an electric field to a catalyst under a certain condition for an apparatus for producing hydrogen by a reaction (steam reforming reaction) in which a hydrocarbon and steam react.
この電場印加による作用について、上記特許文献１の炭化水素の水蒸気改質反応を例にとって説明する。水蒸気改質プロセスは、炭化水素を原料として水（水蒸気）と反応させる水蒸気改質反応（下記式）を利用するプロセスである。 The effect of this electric field application will be described taking the hydrocarbon steam reforming reaction of Patent Document 1 as an example. The steam reforming process is a process using a steam reforming reaction (the following formula) in which a hydrocarbon is used as a raw material to react with water (steam).
この反応は吸熱反応であり、従来型の触媒を使用する場合には反応系を５００℃以上に加熱しなければ実用的な水素転化率が得られない。電場触媒を使用すると、印加した電気エネルギーが上記（１）の反応機構に作用し、触媒活性が向上する。これにより、従来型触媒よりも１００℃以上低温で水素転化率が得られる。 This reaction is an endothermic reaction. When a conventional catalyst is used, a practical hydrogen conversion cannot be obtained unless the reaction system is heated to 500 ° C. or higher. When an electric field catalyst is used, the applied electric energy acts on the reaction mechanism (1), and the catalytic activity is improved. Thereby, a hydrogen conversion rate is obtained at a temperature of 100 ° C. or more lower than that of the conventional catalyst.
電場触媒は、電気エネルギーのアシストにより触媒が有するポテンシャルを有効に引き出すことができる技術といえるが、まだまだ新しい形態の触媒ともいえる。その構成についての最適化や、活性低下に対する対策等の部分で未知のところもある。そこで本発明は、電場触媒の構成に関して効果的な活性向上作用を発揮し得るものを提供することを目的とした。 The electric field catalyst can be said to be a technology that can effectively extract the potential of the catalyst with the assistance of electric energy, but it can be said to be a new type of catalyst. There is also an unknown part about the optimization of the configuration and countermeasures against the decrease in activity. Accordingly, an object of the present invention is to provide a device that can exhibit an effective activity improving action with respect to the configuration of the electric field catalyst.
上記課題を解決する本願発明は、絶縁材料からなるハニカム構造の支持体上に触媒層を形成してなり、電極を前記支持体及び／又は触媒層に接触させ電場を印加して反応促進させる触媒であって、前記触媒層は、イオン・電子混合伝導性セラミックからなる担体粒子に触媒金属を担持させてなる触媒粒子を焼結して形成されるものであり、前記電極間で測定される４５０℃における触媒間抵抗率が５０Ω・ｍ以上２７０Ω・ｍ以下である触媒である。 The present invention that solves the above problems is a catalyst in which a catalyst layer is formed on a support having a honeycomb structure made of an insulating material, and an electrode is brought into contact with the support and / or the catalyst layer and an electric field is applied to promote the reaction. The catalyst layer is formed by sintering catalyst particles obtained by supporting a catalyst metal on carrier particles made of a mixed ion / electron conductive ceramic, and is measured between the electrodes. It is a catalyst having an inter-catalyst resistivity at 50 ° C. of 50 Ω · m to 270 Ω · m.
本発明の対象となる電場触媒における特有の課題として、印加した電気エネルギーを如何に触媒反応の活性化に利用することができるかという点にあるといえる。ここで、本発明者等は触媒の電気抵抗値に着目した。触媒は電気的な抵抗体であるので、印加された電気エネルギーを熱エネルギーに変換する。この熱エネルギーへの変換が過度に大きくなる場合、即ち、電気抵抗が大きすぎる場合、触媒反応に利用される電気エネルギーが減少することとなる。 It can be said that the specific problem in the electric field catalyst which is the subject of the present invention is how the applied electric energy can be utilized for the activation of the catalytic reaction. Here, the present inventors paid attention to the electric resistance value of the catalyst. Since the catalyst is an electrical resistor, the applied electrical energy is converted into thermal energy. If this conversion to thermal energy becomes excessively large, that is, if the electrical resistance is too large, the electrical energy used for the catalytic reaction will decrease.
印加した電気エネルギーが過剰に熱エネルギーに変換することのデメリットは、利用される電気エネルギーが減少するだけではない。過剰な熱エネルギーへの変換は、触媒の溶損の要因となる。この溶損とは、触媒の構成材料が熱により溶融する現象であり、必ずしも目視できるようなものに限られず微視的・局所的な損傷もある。かかる触媒の溶損現象の発生メカニズムについては必ずしも明らかではない。本発明者等の考察では、変換した熱エネルギーそのものによる溶融の他、熱エネルギーにより触媒粒子が加熱されたことで触媒金属のシンタリング等が生じ、それにより活性が低下したところに過剰な電気エネルギーが印加されたことで溶融が発生し、これらのサイクルによって損傷領域が広がるという悪循環によって触媒の溶損は生じると考察している。 The demerit of excessively converting applied electrical energy into thermal energy is not only a reduction in the electrical energy used. The conversion to excessive heat energy causes catalyst erosion. This melting loss is a phenomenon in which the constituent material of the catalyst is melted by heat, and is not necessarily limited to what can be visually observed, and there is also microscopic / local damage. The mechanism of occurrence of such a catalyst erosion phenomenon is not always clear. In the inventors' consideration, in addition to melting by the converted thermal energy itself, catalyst particles are heated by the thermal energy, resulting in catalyst metal sintering, etc., resulting in a decrease in activity and excessive electrical energy. It is considered that the melting of the catalyst occurs due to the application of, and the catalyst melts due to the vicious cycle in which the damaged region is expanded by these cycles.
本発明は、以上のような考察を基礎になされたものであり、触媒の電気抵抗値（触媒間抵抗率）を適正範囲とし、印加した電気エネルギーについて熱エネルギーの過度の変換を抑制し、電気エネルギーを触媒反応に有効に利用しつつ、溶損を抑制しようとするものである。そのために、触媒の各構成（支持体、触媒粒子（担体、触媒金属））を好適化したものである。以下、本発明の各構成について詳細に説明する。 The present invention has been made on the basis of the above-described considerations. The electric resistance value (inter-catalyst resistivity) of the catalyst is set within an appropriate range, and excessive conversion of heat energy is suppressed for the applied electric energy. It is intended to suppress melting loss while effectively using energy for catalytic reaction. For this purpose, each component of the catalyst (support, catalyst particles (carrier, catalyst metal)) is optimized. Hereafter, each structure of this invention is demonstrated in detail.
本発明に係る触媒は、所定の支持体上に触媒層を形成してなるものである。また、この触媒層は、担体粒子に触媒金属を担持させてなる触媒粒子で構成される。電場触媒の形態については、本発明のようなハニカム構造の支持体を使用してここに電極を接触させる形態以外に、触媒粒子を成形固化した錠剤型又はペレット型の触媒に電極を接触させる形態、或いは、成形固化した触媒を粉砕して反応器に充填しそこに電極を接触させる形態等いくつかの形態の採用が考え得る。本発明者等の検討によれば、触媒粒子を成形固化する場合、触媒反応におけるガスの拡散が困難となって触媒活性の向上が望めない。また、成形した触媒を粉砕したものを充填して使用するとき、電極との接触状態に問題が生じ触媒間抵抗の観点で好適な状態にすることが困難となる（この点については、後に詳述する。）。そこで、本発明者等は、反応ガスの拡散性の確保、電場印加の際の電極との接触を考慮してハニカム構造の支持体に触媒層を形成する形態とした。 The catalyst according to the present invention is obtained by forming a catalyst layer on a predetermined support. The catalyst layer is composed of catalyst particles in which a catalyst metal is supported on carrier particles. Regarding the form of the electric field catalyst, in addition to the form in which the electrode is brought into contact with the support having a honeycomb structure as in the present invention, the form in which the electrode is brought into contact with the tablet-type or pellet-type catalyst in which the catalyst particles are molded and solidified. Alternatively, it may be possible to adopt several forms such as a form in which the molded and solidified catalyst is pulverized and charged into a reactor and an electrode is brought into contact therewith. According to the study by the present inventors, when the catalyst particles are molded and solidified, it is difficult to diffuse the gas in the catalytic reaction, and improvement in the catalytic activity cannot be expected. In addition, when the molded catalyst is used after being pulverized, there is a problem in the contact state with the electrode, and it becomes difficult to achieve a suitable state in terms of resistance between the catalysts (this point will be described in detail later). To state.) In view of this, the present inventors have taken a form in which a catalyst layer is formed on a support having a honeycomb structure in consideration of ensuring the diffusibility of the reaction gas and contact with the electrode when an electric field is applied.
そして、電場触媒においては、電場印加のための電極が支持体及び／又は触媒層に電気的に接続されて通電される。このとき支持体が導電体であると、電気が支持体にも流れるため、触媒層に十分なエネルギーが供給されない。そこで、本発明では、支持体を絶縁体で形成することとしている。支持体の構成材料としては、コージェライト、アルミナ、ムライト、等のセラミックが好ましい。尚、支持体の形状は特に限定されることはないが、ハニカム形状の支持体が好適である。 And in an electric field catalyst, the electrode for an electric field application is electrically connected to a support body and / or a catalyst layer, and it supplies with electricity. At this time, if the support is a conductor, electricity flows also to the support, so that sufficient energy is not supplied to the catalyst layer. Therefore, in the present invention, the support is formed of an insulator. The constituent material of the support is preferably a ceramic such as cordierite, alumina, mullite. The shape of the support is not particularly limited, but a honeycomb-shaped support is preferable.
本発明において、触媒層は触媒粒子を焼結して形成されるが、この触媒粒子は、イオン・電子混合伝導性セラミックからなる担体粒子に触媒金属を担持させてなる。担体であるイオン・電子混合伝導性セラミックとは、電荷（電子、ホール）伝導性とイオン伝導性の双方を具備する性質を有するセラミックである。電場触媒において、担体にイオン・電子混合伝導性を要求するのは目的とする反応条件（温度）において、印加した電場に応じて導電性を発揮させるためである。本発明ではセラミック支持体を利用しており、担体についても一般的なセラミック粒子（アルミナ等）を適用する場合、如何に電場を印加しても十分な導電性を発揮し得ない。イオン・電子混合伝導性セラミックは、加熱による熱エネルギー付与等でイオン移動現象を発生させるものであり、これにより導電性を確保することができる。即ち、電場触媒とは、常温での導電性には乏しいが、反応温度に加熱することで導電性が増大し電気エネルギーが触媒活性の向上に利用される。この加熱による導電性の増大こそ電場触媒の特色の一つであり、これを発現させるためにイオン・電子混合伝導性セラミックからなる担体が採用される。 In the present invention, the catalyst layer is formed by sintering catalyst particles. The catalyst particles are formed by supporting a catalyst metal on carrier particles made of a mixed conductive ceramic of ions and electrons. The ion / electron mixed conductive ceramic as a carrier is a ceramic having a property having both electric charge (electron, hole) conductivity and ionic conductivity. In the electric field catalyst, the support of the ion / electron mixed conductivity is required for the support in order to exhibit the electric conductivity according to the applied electric field under the target reaction condition (temperature). In the present invention, a ceramic support is used, and when general ceramic particles (alumina or the like) are applied to the carrier, sufficient electrical conductivity cannot be exhibited no matter how the electric field is applied. The ion / electron mixed conductive ceramic generates an ion transfer phenomenon by applying thermal energy by heating, and thereby can ensure conductivity. That is, the electric field catalyst is poor in electrical conductivity at room temperature, but when heated to the reaction temperature, the electrical conductivity increases and electric energy is utilized for improving the catalytic activity. This increase in conductivity by heating is one of the characteristics of the electrocatalyst, and a carrier made of a mixed ionic / electron conductive ceramic is employed to develop this.
このイオン・電子混合伝導性セラミックとしては、特に、酸素イオン伝導性を有するイオン・電子混合伝導性セラミックを使用することが好ましい。イオン・電子混合伝導性セラミックからなる担体の具体例としては、酸化セリウム（セリア）、酸化ジルコニウム（ジルコニア）、酸化ビスマスのいずれかを少なくとも１種含むものとなる。 As this ion / electron mixed conductive ceramic, it is particularly preferable to use an ion / electron mixed conductive ceramic having oxygen ion conductivity. As a specific example of the carrier made of the mixed conductive ion / electron ceramic, at least one of cerium oxide (ceria), zirconium oxide (zirconia), and bismuth oxide is included.
担体は、イオン・電子混合伝導性セラミックであるセリア、ジルコニア等が単独で構成していても良いが、それらの１種を含むものであれば良い。複数のイオン・電子混合伝導性セラミックが混合していても良い。また、セリア等に他の酸化物（アルミナ、シリカ等）との混合した混合酸化物の態様であっても良い。更に、セリア等のイオン・電子混合伝導性セラミックに他の元素を固溶させた状態のものでも良い。 The carrier may be composed of ceria, zirconia, or the like, which is an ion / electron mixed conductive ceramic, but may be one containing one of them. A plurality of ion / electron mixed conductive ceramics may be mixed. Moreover, the aspect of the mixed oxide which mixed ceria etc. with other oxides (alumina, silica, etc.) may be sufficient. Furthermore, it may be in a state where other elements are dissolved in an ion / electron mixed conductive ceramic such as ceria.
上記のようなイオン・電子混合伝導性セラミックからなる担体粒子に担持する触媒金属は、ロジウム、ルテニウム、白金、イリジウム、パラジウム、ニッケルの少なくともいずれかとなる。触媒金属は、目的とする化学反応に応じて選択できる。例えば、上記した水蒸気改質反応における電場触媒としては、触媒金属としてロジウム、ルテニウムの適用が好適である。 The catalyst metal supported on the carrier particles made of the above ionic / electron mixed conductive ceramic is at least one of rhodium, ruthenium, platinum, iridium, palladium, and nickel. The catalyst metal can be selected according to the target chemical reaction. For example, as the electric field catalyst in the steam reforming reaction described above, rhodium or ruthenium is preferably used as the catalyst metal.
上記の通り、電場触媒は加熱によるイオン移動現象により導電性を増大させるものであるが、本発明ではこのときの触媒間抵抗率（Ω・ｍ）を所定範囲に規定する。この触媒間抵抗率とは、電場印加のために触媒に接触させた一対（２極）の電極間における触媒の電気抵抗率である。その測定・算出方法としては、２極の電極で挟まれた触媒構造体に対して電気抵抗Ｒ（Ω）を測定し、電極が設置された面間の断面積Ａ（ｍ２）と電極間の距離Ｌ（ｍ）から、下記式によりその触媒固有の触媒間抵抗率（Ω・ｍ）が算出される。 As described above, the electric field catalyst increases conductivity by an ion transfer phenomenon caused by heating. In the present invention, the inter-catalyst resistivity (Ω · m) is defined within a predetermined range. This inter-catalyst resistivity is the electrical resistivity of the catalyst between a pair (two poles) of electrodes brought into contact with the catalyst for applying an electric field. As a measurement / calculation method, an electrical resistance R (Ω) is measured for a catalyst structure sandwiched between two electrodes, and a cross-sectional area A (m 2 ) between the surfaces where the electrodes are installed is measured between the electrodes. From the distance L (m), the inter-catalyst resistivity (Ω · m) specific to the catalyst is calculated by the following equation.
本発明では、触媒の温度が４５０℃である時点における触媒間抵抗率が５０Ω・ｍ以上２７０Ω・ｍ以下であることを要する。この触媒間抵抗率の規定は、本発明者等の検討に基づき、電気エネルギーの効率的利用を考慮しつつ触媒活性を確保するために得られた知見である。即ち、触媒間抵抗率が２７０Ω・ｍを超える触媒では、印加した電気エネルギーの熱エネルギーへの変換が過度に生じ、触媒の溶損が生じる可能性も生じる。一方、触媒間抵抗率が５０Ω・ｍ未満となると、電子伝導性が優位になるため触媒活性向上に電気エネルギーが利用されていない（電場印加のない）状態となり、活性の向上が期待できなくなる。 In the present invention, the inter-catalyst resistivity at the time when the temperature of the catalyst is 450 ° C. is required to be 50 Ω · m to 270 Ω · m. The regulation of the inter-catalyst resistivity is a knowledge obtained in order to ensure the catalytic activity while considering the efficient use of electric energy based on the study by the present inventors. That is, in a catalyst having an inter-catalyst resistivity exceeding 270 Ω · m, conversion of applied electric energy to thermal energy occurs excessively, and there is a possibility that the catalyst may be melted. On the other hand, when the inter-catalyst resistivity is less than 50 Ω · m, the electron conductivity becomes superior, and thus electric energy is not used for improving the catalyst activity (no electric field is applied), and the improvement in activity cannot be expected.
また、本発明では、触媒間抵抗率の数値範囲について、特定温度（４５０℃）での抵抗値を基準とする。本発明で４５０℃を基準温度とするのは、本発明に係る触媒が供される反応（例えば、水蒸気改質反応等）の多くは、反応温度が４５０〜６００℃の範囲内で設定されることから、下限値である４５０℃を基準とするのが適当だからである。尚、触媒の支持体は筒状体（円筒、角筒）が一般的であり、通常は、支持体の両端面に電極が設置される。触媒間抵抗率は両端面の任意位置に電極を設置し、それらを正極側・負極側に接続して測定することができる。 Moreover, in this invention, the resistance value in specific temperature (450 degreeC) is made into a reference | standard about the numerical range of the resistivity between catalysts. In the present invention, the reference temperature is set to 450 ° C. Most of reactions (for example, steam reforming reaction, etc.) in which the catalyst according to the present invention is provided are set within a reaction temperature range of 450 to 600 ° C. For this reason, it is appropriate to use the lower limit of 450 ° C. as a reference. The catalyst support is generally a cylindrical body (cylinder, square tube), and usually electrodes are provided on both end faces of the support. The inter-catalyst resistivity can be measured by installing electrodes at arbitrary positions on both end faces and connecting them to the positive electrode side and the negative electrode side.
以上のとおり、本発明では、イオン・電子混合伝導性セラミックに触媒金属を担持した触媒層を支持体に形成しつつ、触媒間抵抗率が所定範囲内となるようにする。ここで、触媒間抵抗率を適正範囲内にする具体的な手法としては、まず、触媒層を構成する触媒粒子の焼結状態を適正にすることが挙げられる。ここで、触媒粒子の焼結状態と触媒間抵抗率との関係について説明する。触媒層は、無数の触媒粒子が接触・焼結して形成されるものであり、触媒粒子の粒径は触媒粒子同士の接触界面の数に影響を及ぼす。図１のように、触媒粒子が粗大な場合（図１（ａ））の接触界面は１２点であるが、粒径を半分にすることで接触界面の数は５倍の６０点と一気に増加する（図１（ｂ））。ここで、触媒層の電気抵抗は、触媒粒子同士の接触界面が増加することで低減すると予測される。従って、触媒間抵抗率を低減するためには、粒子径の小さい触媒粒子を微細にして緻密な焼結状態にすることが求められると考えられる。もっとも、触媒粒子の粒径が過度に微小で緻密に焼結すると、接触界面の増加と共に抵抗は小さくなるものの、そうなると上記の通り、触媒粒子での電気エネルギーの利用が不十分となる。また、過度の微小化・過度の焼結による接触界面の増加は、触媒粒子の表面積の減少を意味することから、触媒本来の活性が低下する。 As described above, in the present invention, the inter-catalyst resistivity falls within a predetermined range while the catalyst layer in which the catalyst metal is supported on the ion / electron mixed conductive ceramic is formed on the support. Here, as a specific method for setting the inter-catalyst resistivity within an appropriate range, first, the sintering state of the catalyst particles constituting the catalyst layer is made appropriate. Here, the relationship between the sintering state of the catalyst particles and the inter-catalyst resistivity will be described. The catalyst layer is formed by contacting and sintering innumerable catalyst particles, and the particle size of the catalyst particles affects the number of contact interfaces between the catalyst particles. As shown in FIG. 1, when the catalyst particles are coarse (FIG. 1 (a)), the number of contact interfaces is 12 points, but by halving the particle size, the number of contact interfaces increases 5 times to 60 points at a stretch. (FIG. 1B). Here, the electrical resistance of the catalyst layer is predicted to decrease as the contact interface between the catalyst particles increases. Therefore, in order to reduce the inter-catalyst resistivity, it is considered that the catalyst particles having a small particle diameter are required to be finely made into a dense sintered state. However, when the particle size of the catalyst particles is excessively small and densely sintered, the resistance decreases as the contact interface increases. However, as described above, utilization of electric energy in the catalyst particles becomes insufficient. Further, an increase in the contact interface due to excessive miniaturization and excessive sintering means a decrease in the surface area of the catalyst particles, so that the original activity of the catalyst decreases.
本発明者等は、このような関係を考慮し、好適な触媒粒子の性状として、粒子径が０．３５μｍ以上６．０μｍ以下となっているものを設定している。粒子径は平均粒径の意義である。触媒粒子の各種パラメータを上記のように規定するのは、触媒粒子同士の接触状態について、触媒活性を確保しつつ触媒間抵抗率が良好で好適な接触状態を形成するためである。 In consideration of such a relationship, the present inventors set a suitable catalyst particle property having a particle diameter of 0.35 μm or more and 6.0 μm or less. The particle diameter is the meaning of the average particle diameter. The reason why the various parameters of the catalyst particles are defined as described above is to form a suitable contact state with good inter-catalyst resistivity while ensuring catalytic activity for the contact state between the catalyst particles.
また、触媒間抵抗率の適正化については、上記触媒粒子の性状を規定することの他、触媒粒子のボリュームを調整することも好ましい。この触媒粒子の好適なボリュームとしては、担体粒子の量について支持体の体積基準で１５０ｇ／Ｌ以上３５０ｇ／Ｌ以下となっているものが好ましい。 In addition, regarding the optimization of the inter-catalyst resistivity, it is also preferable to adjust the volume of the catalyst particles in addition to defining the properties of the catalyst particles. A preferable volume of the catalyst particles is preferably a volume of 150 g / L or more and 350 g / L or less based on the volume of the support with respect to the amount of the carrier particles.
以上のように、触媒粒子の性状及び／又は担体量を調整することで、好適な触媒間抵抗率を有する電場触媒を得ることができる。ここで、本発明については、更に電気エネルギーの効率的利用を図るという観点から、支持体の電極との接触面に金属膜を形成したものが好ましい。この金属膜は、電極と支持体（触媒）との接触界面の状態を調整し、電場印加の際の支持体にかかる電流拡散を促進して電気エネルギーを有効利用し、溶損の発生を抑制するためのものである。 As described above, an electric field catalyst having a suitable inter-catalyst resistivity can be obtained by adjusting the properties of the catalyst particles and / or the carrier amount. Here, in the present invention, it is preferable to form a metal film on the contact surface of the support with the electrode from the viewpoint of further efficient use of electric energy. This metal film adjusts the state of the contact interface between the electrode and the support (catalyst), promotes current diffusion to the support when an electric field is applied, effectively uses electrical energy, and suppresses the occurrence of melting damage Is to do.
この金属膜の構成金属は、Ｐｔ、Ａｕ、Ｐｄが好ましい。本発明者等によると、これら金属からなる金属膜によって、触媒活性を好適にすることができる。そして、これらの金属膜がない場合、局所的ながら触媒の溶損が生じ得る。金属膜の膜厚は、１μｍ以上３００μｍ以下が好ましい。１μｍ未満は実質的に金属膜のない状態なので溶損が生じる可能性があり、３００μｍを超えると金属膜の剥離が生じるおそれがある。また、支持体としてセラミックハニカム等の多孔質体を使用する場合、金属膜は支持体表面の孔部分に浸透しているものが好ましい。このときの深さは、５〜４００μｍとするのが好ましい。 The constituent metal of this metal film is preferably Pt, Au, or Pd. According to the present inventors, the catalytic activity can be made suitable by the metal film made of these metals. In the absence of these metal films, the catalyst can be locally melted. The thickness of the metal film is preferably 1 μm or more and 300 μm or less. If the thickness is less than 1 μm, there is a possibility that the metal film does not have a metal film, so that melting damage may occur. When a porous body such as a ceramic honeycomb is used as the support, it is preferable that the metal film penetrates into the pores on the support surface. The depth at this time is preferably 5 to 400 μm.
本発明に係る電場触媒は、各種反応に供され電場を印加することで、他のエネルギー（熱等）の入力量を低減しながら反応を進行させる。本発明が有用な化学プロセスの好例として、上記した水蒸気改質反応が挙げられる。水蒸気改質方法は、炭化水素を含むガスと水蒸気とを触媒の存在下で反応させ水蒸気改質反応により水素を製造する方法である。このとき、触媒として本発明に係る電場触媒を適用し、触媒に電場を印加して反応を進行させることができる。 The electric field catalyst according to the present invention is subjected to various reactions and applies an electric field to advance the reaction while reducing the input amount of other energy (heat or the like). A good example of a chemical process in which the present invention is useful is the steam reforming reaction described above. The steam reforming method is a method for producing hydrogen by a steam reforming reaction by reacting a gas containing hydrocarbon and steam in the presence of a catalyst. At this time, the electric field catalyst according to the present invention can be applied as a catalyst, and an electric field can be applied to the catalyst to advance the reaction.
本発明に係る触媒の使用条件について、印加する電場に制限はない。但し、本発明で使用される担体材料はイオン混合伝導体材料であり、一般的な導電材料に比べて界面抵抗が高いために高電圧を印加するのが好適である。但し、過度の高電圧を印加すると絶縁破壊が発生して触媒基材が破壊される。そのため、本発明を各種触媒反応において好適に利用するため、０．１ｋＶ以上２ｋＶ以下の印加電圧を設定するのが好ましい。尚、ここで印加する電圧は直流であり、電流値は１ｍＡ以上１００ｍＡ以下程度となる。 There is no restriction | limiting in the electric field applied about the use conditions of the catalyst which concerns on this invention. However, since the carrier material used in the present invention is an ionic mixed conductor material and has a higher interface resistance than a general conductive material, it is preferable to apply a high voltage. However, if an excessively high voltage is applied, dielectric breakdown occurs and the catalyst base material is destroyed. Therefore, in order to suitably use the present invention in various catalytic reactions, it is preferable to set an applied voltage of 0.1 kV or more and 2 kV or less. The voltage applied here is a direct current, and the current value is about 1 mA to 100 mA.
次に、本発明に係る触媒の製造方法について説明する。本発明に係る触媒は、基本的な製造工程は従来品と同様である。従来法としては、担体となるイオン・電子混合伝導性セラミックをゾル化して支持体に塗布し、ここに触媒金属の化合物溶液を接触・担持して、焼成することで触媒層を製造できる。また、まず無機酸化物担体に触媒金属を担持させ焼成して触媒粒子を先に製造し、これをゾル化して支持体に塗布して触媒層を形成しても良い。 Next, the method for producing the catalyst according to the present invention will be described. The basic production process of the catalyst according to the present invention is the same as that of the conventional product. As a conventional method, a catalyst layer can be produced by soluting an ion / electron mixed conductive ceramic serving as a carrier and applying it to a support, contacting and supporting a catalyst metal compound solution thereon, and firing. Alternatively, the catalyst metal may be first supported on an inorganic oxide carrier and calcined to produce catalyst particles in advance, and the catalyst particles may be formed into a sol and applied to a support to form a catalyst layer.
本発明に係る触媒はいずれの工程でも製造できるが、触媒間抵抗率を制御するため、触媒層の形成の際に触媒粒子の粒径等が所定範囲の状態で焼結されるようにする必要がある。また、担体粒子の担持量にも配慮する必要がある。更に、触媒の電極との接触面について、好適な状態の金属膜を形成する必要がある。以下、これらの特徴部分を考慮しつつ本発明に係る触媒の製造方法について説明する。 The catalyst according to the present invention can be produced by any process, but in order to control the inter-catalyst resistivity, it is necessary to sinter the catalyst particles in a predetermined range when the catalyst layer is formed. There is. It is also necessary to consider the amount of carrier particles supported. Furthermore, it is necessary to form a metal film in a suitable state on the contact surface of the catalyst with the electrode. Hereinafter, the manufacturing method of the catalyst according to the present invention will be described in consideration of these characteristic portions.
触媒層を構成する触媒粒子は、イオン・電子混合伝導性セラミックからなる担体に触媒金属の化合物溶液を接触させ、焼成することで製造される（上記の通り、担体は、予め支持体上に塗布されている場合もある。）。この工程において、触媒金属の化合物溶液は、硝酸塩、水酸塩、リン酸塩、塩化物、の水溶液が好ましい。ゾル化した担体或いはゾル化した触媒粒子を支持体に塗布する際、その分散溶媒は、水、有機溶媒、又はそれらの混合からなる溶媒が使用できる。尚、本発明では、担体量の調整を通して触媒間抵抗率を好適にすることができる。担体量は、触媒粒子又は担体粒子のゾルを支持体に塗布する際に、ゾルの濃度又は塗布回数で調整可能である。 The catalyst particles constituting the catalyst layer are produced by bringing a catalyst metal compound solution into contact with a carrier made of a mixed conductive ceramic of ion / electron and calcining (as described above, the carrier is previously coated on a support). In some cases.) In this step, the catalyst metal compound solution is preferably an aqueous solution of nitrate, hydrochloride, phosphate, or chloride. When the sol-form carrier or the sol-form catalyst particles are applied to the support, the dispersion solvent can be water, an organic solvent, or a solvent composed of a mixture thereof. In the present invention, the inter-catalyst resistivity can be made suitable through adjustment of the carrier amount. The amount of the carrier can be adjusted by the concentration of the sol or the number of coatings when the catalyst particles or the sol of the carrier particles is coated on the support.
そして、担体に触媒金属の化合物溶液を接触させた後、乾燥及び焼成することで触媒粒子が形成される。これら乾燥工程及び焼成工程は、触媒粒子（担体粒子）の粒径等を調整し好適な界面抵抗とするために重要な工程である。 Then, after bringing the catalyst metal compound solution into contact with the carrier, the catalyst particles are formed by drying and firing. These drying step and calcination step are important steps in order to adjust the particle size of the catalyst particles (carrier particles) to obtain a suitable interface resistance.
乾燥工程は、焼成工程に先立ち行われる工程であり、ゾルが塗布された基材から適度に水分や有機物等を加熱除去する工程である。この乾燥工程における加熱温度が高すぎると、ゾルに含まれる水分が一気に揮発して過大な細孔が形成されてしまい、粒子の焼結状態を密とすることができなくなる。また、高温での乾燥は不均一な乾燥の要因になり易く、粒子の焼結状態を不均一にする。即ち、塗布されたゾルの量が少ない部分（水分量の少ない部分）が優先的に乾燥し、そこに隣接するゾルが乾燥した部分に引き寄せられ順次乾燥を繰り返すため、結果的に担体粒子が密な部分と粗な部分が形成されてしまう。このようなことから、本発明では、乾燥工程における加熱温度を５０℃以上１５０℃以下と比較的低温に設定する。これにより、ゾル中の水分除去が全体的に緩やかとなりゾルを塗布した状態のままで粒子が残る。そして、その後の焼成工程により、密で均一な担体の焼結状態が発現することとなる。 The drying process is a process that is performed prior to the firing process, and is a process in which moisture, organic matter, and the like are appropriately removed by heating from the sol-coated substrate. If the heating temperature in this drying step is too high, the water contained in the sol volatilizes all at once and excessive pores are formed, and the sintered state of the particles cannot be made dense. Also, drying at high temperature tends to cause uneven drying, which makes the sintered state of the particles uneven. That is, a portion with a small amount of applied sol (a portion with a small amount of water) is preferentially dried, and the adjacent sol is attracted to the dried portion and repeatedly dried, resulting in dense carrier particles. A rough portion and a rough portion are formed. For this reason, in the present invention, the heating temperature in the drying step is set to a relatively low temperature of 50 ° C. or more and 150 ° C. or less. As a result, the removal of water in the sol becomes gentle as a whole, and particles remain in a state where the sol is applied. Then, a dense and uniform sintered state of the carrier is developed by the subsequent firing step.
そして、乾燥工程に続く焼成工程で、触媒粒子は好適な結晶子径まで成長させる。この焼成温度は、粒子同士の結合によるネックを形成しつつ、好適な結晶子径の維持が可能な温度範囲として、４００℃以上６００℃以下とする。６００℃を超える場合、粒子同士の焼結が過度に促進され二次粒子、三次粒子が成長し触媒粒子径が好適範囲を超え触媒間低効率の高い触媒が製造される。また、４００℃未満と焼成温度が低すぎると、粒子同士の結合が不足してネックが形成されず密着強度が低下する。尚、焼成時間は３０分以上とするのが好ましい。 Then, in the firing step subsequent to the drying step, the catalyst particles are grown to a suitable crystallite size. This firing temperature is set to 400 ° C. or more and 600 ° C. or less as a temperature range in which a suitable crystallite diameter can be maintained while forming a neck due to bonding between particles. When the temperature exceeds 600 ° C., the sintering of the particles is excessively promoted, and the secondary particles and the tertiary particles grow, so that the catalyst particle diameter exceeds the preferred range and a catalyst with high efficiency between the catalysts is produced. On the other hand, if it is less than 400 ° C. and the firing temperature is too low, the bonding between the particles is insufficient, the neck is not formed, and the adhesion strength is lowered. The firing time is preferably 30 minutes or longer.
尚、以上の焼成条件は担体粒子の粒径等の調整を考慮したものであるので、支持体に担体だけを塗布し、上記焼成条件で焼成を行った後に触媒金属を担持させても所望の触媒層を形成することができる。 In addition, since the above calcination conditions consider the adjustment of the particle size and the like of the carrier particles, it is possible to apply the catalyst metal on the support and apply the catalyst metal after calcination under the above calcination conditions. A catalyst layer can be formed.
以上の通り本発明は、電場触媒という新たな形態の触媒について、印加された電気エネルギーを触媒反応へ効果的に利用すると共に、溶損という特異な損傷を抑制するための有用な構成を提示する。本発明の構成における最適化は、電場印加によるメリッを発揮させつつ、安定的な稼動を可能とすることができる。 As described above, the present invention presents a useful configuration for effectively utilizing the applied electric energy for the catalytic reaction and suppressing specific damages such as erosion with respect to a new type of catalyst called an electric field catalyst. . The optimization in the configuration of the present invention can enable stable operation while demonstrating the merit of applying an electric field.
第１実施形態：以下、本発明の実施形態について説明する。本実施形態では、触媒層形成の際の条件を変更しつつ、触媒粒子の粒径の異なる複数の触媒を製造した。 First Embodiment Hereinafter, an embodiment of the present invention will be described. In the present embodiment, a plurality of catalysts having different catalyst particle diameters were manufactured while changing the conditions for forming the catalyst layer.
本実施形態では、支持体としてセラミック製（コージェライト製）のハニカム基材（商品名：ハニセラム（登録商標）、日本ガイシ製、セル数：６００ｃｐｓｉ、φ２０×６０ｍｍ、を使用した。 In this embodiment, a ceramic (made of cordierite) honeycomb substrate (trade name: Haniseram (registered trademark), manufactured by NGK, cells: 600 cpsi, φ20 × 60 mm) was used as the support.
本実施形態では、支持体であるセラミックハニカムの端面に金属膜を形成した。金属膜の形成は、平坦なプレート上に白金ペースト（商品名ＴＲ−７０９１、田中貴金属製、導体抵抗１５±５Ωｍ／□／１０μｍ）を刷毛にて塗布した。ペースト塗布は両端面に行った。その後、１０００℃で焼成して白金からなる金属膜を形成した。 In the present embodiment, the metal film is formed on the end face of the ceramic honeycomb that is the support. The metal film was formed by applying a platinum paste (trade name TR-7091, made by Takanaka Tanaka, conductor resistance 15 ± 5 Ωm / □ / 10 μm) on a flat plate with a brush. Paste application was performed on both end faces. Then, it baked at 1000 degreeC and the metal film which consists of platinum was formed.
次に、担体としてセリア粉末４０ｇと純水８０ｇとをボールミルにて２０分混合してゾルを作成した。本実施形態では、平均粒子径の相違するセリア粉末（Ａ、Ｂ、Ｃ）を用意しそのゾルを使用した。このゾルを支持体の全面に塗布（ウォッシュコート）して乾燥後５００℃で６０分間焼成して担体を作成した。担体の量は、支持体の容量基準で２００ｇ／Ｌとなるようにした。 Next, 40 g of ceria powder and 80 g of pure water as a carrier were mixed in a ball mill for 20 minutes to prepare a sol. In this embodiment, ceria powders (A, B, C) having different average particle diameters were prepared and the sol was used. This sol was applied to the entire surface of the support (wash coat), dried, and then fired at 500 ° C. for 60 minutes to prepare a carrier. The amount of the carrier was set to 200 g / L based on the volume of the support.
このハニカム上に形成された担体に触媒金属の化合物溶液を含浸した。本実施形態では触媒金属としてＲｈを担持することとした。硝酸ロジウム溶液をハニカム担体に含浸した後、乾燥工程及び焼成工程を経て触媒層を形成し水蒸気改質触媒を得た。尚、本実施形態では、Ｒｈ担持量を支持体の容量基準で０．５ｇ／Ｌとなるようにした。ここで、本実施形態では、乾燥工程を１２０℃で３０分加熱と共通させつつ、焼成工程の加熱温度について複数条件を設定して触媒層の触媒粒子の性状の異なる複数の触媒を製造した。 The carrier formed on the honeycomb was impregnated with a catalyst metal compound solution. In this embodiment, Rh is supported as the catalyst metal. After impregnating the honeycomb carrier with the rhodium nitrate solution, a catalyst layer was formed through a drying step and a firing step to obtain a steam reforming catalyst. In the present embodiment, the amount of Rh supported is 0.5 g / L based on the volume of the support. Here, in the present embodiment, a plurality of catalysts having different properties of catalyst particles in the catalyst layer were manufactured by setting a plurality of conditions for the heating temperature of the firing step while making the drying step common to heating at 120 ° C. for 30 minutes.
製造した触媒について、平均粒径、粒径分布を測定した。これらの測定は、触媒層の断面をＳＥＭ観察し（本実施形態における観察視野面積は０．００２４ｍｍ２×５か所とした）、観察された複数の粒子についての直径を測定・平均化したものを触媒粒子のサイズと規定した。更に、メソ孔径及び表面積を窒素吸着によるＢＥＴ法にて測定した。（測定装置：日本ベル ＢＥＬ−ＳＯＲＰ−ＭＩＮＩ） About the manufactured catalyst, the average particle diameter and the particle size distribution were measured. In these measurements, the cross section of the catalyst layer was observed with an SEM (the observation visual field area in this embodiment was 0.0024 mm 2 × 5), and the diameters of the observed particles were measured and averaged. Was defined as the size of the catalyst particles. Furthermore, the mesopore diameter and surface area were measured by the BET method using nitrogen adsorption. (Measuring device: Nippon Bell BEL-SORP-MINI)
そして、製造した触媒について触媒間抵抗率の測定及び活性評価の試験を行った。活性評価は、水蒸気改質反応についての活性評価を行った。この反応試験では、固定床式触媒反応装置の石英反応管にハニカム触媒をセットし、電極（正極、負極）をそれぞれ金属膜に接触させた。そして反応ガスを導入し、水蒸気改質反応を進行させた。また、反応試験後に溶損の有無も確認した。詳細な反応条件は下記の通りである。 And the test of the measurement of activity between catalysts and activity evaluation was done about the manufactured catalyst. In the activity evaluation, the activity of the steam reforming reaction was evaluated. In this reaction test, a honeycomb catalyst was set in a quartz reaction tube of a fixed bed type catalyst reaction apparatus, and electrodes (positive electrode and negative electrode) were brought into contact with metal films, respectively. And reaction gas was introduce | transduced and the steam reforming reaction was advanced. Moreover, the presence or absence of melting damage was also confirmed after the reaction test. Detailed reaction conditions are as follows.
・反応ガス：メタン３９３ｍＬ/ｍｉｎ＋水６３１μＬ／ｍｉｎ＋窒素７．０７Ｌ／ｍｉｎ
・空間速度（ＳＶ）：２５０００／ｈ
・Ｓ／Ｃ（スチーム／カーボン比）：２．０
・反応温度：４５０℃（常圧）
・反応時間：１時間
・電極間距離：０．０６ｍ
・電極設置部の断面積：０．０００３１４ｍ２
・印加電場： ０Ｗ 電場無し
５Ｗ （電圧５００Ｖ、電流１０ｍＡ）
１０Ｗ （電圧８００Ｖ、電流１２．５ｍＡ）
Reaction gas: methane 393 mL / min + water 631 μL / min + nitrogen 7.07 L / min
・ Space velocity (SV): 25000 / h
S / C (steam / carbon ratio): 2.0
-Reaction temperature: 450 ° C (normal pressure)
・ Reaction time: 1 hour ・ Distance between electrodes: 0.06 m
-Cross-sectional area of the electrode installation part: 0.000314 m 2
・ Applied electric field: 0W No electric field 5W (Voltage 500V, Current 10mA)
10W (Voltage 800V, Current 12.5mA)
上記条件で反応試験中、触媒に接触させた電極間の電気抵抗を測定し、触媒間抵抗率を算出した。この反応試験について、測定された触媒間抵抗率、触媒活性（メタン転化率）の結果は表１のとおりであった。 During the reaction test under the above conditions, the electrical resistance between the electrodes in contact with the catalyst was measured, and the inter-catalyst resistivity was calculated. Table 1 shows the results of the measured inter-catalyst resistivity and catalytic activity (methane conversion rate) for this reaction test.
この試験結果から、本実施形態で製造した触媒は、いずれも電場印加により活性（メタン転化率）が向上することが分かる。但し、触媒間低効率の大きい触媒（Ｎｏ．６、７）は高電圧印加の際に溶損が生じるため触媒としての機能を失う。ここで、触媒間抵抗率と触媒粒子径との関係を見ると、粒子径が０．３５μｍ以上６．０μｍ以下とすることで触媒間抵抗率が好適範囲となる（Ｎｏ．２〜５）。尚、その他の物性であるＢＥＴ表面積、メソ孔面積についても好適範囲内にある。 From this test result, it can be seen that the activity (methane conversion) of the catalyst produced in this embodiment is improved by applying an electric field. However, the catalyst (Nos. 6 and 7) having a high efficiency between the catalysts loses its function as a catalyst because melting damage occurs when a high voltage is applied. Here, looking at the relationship between the inter-catalyst resistivity and the catalyst particle diameter, the inter-catalyst resistivity falls within a suitable range when the particle diameter is 0.35 μm or more and 6.0 μm or less (No. 2 to 5). The other physical properties such as the BET surface area and mesopore area are also in the preferred range.
そして、これらの好適な触媒を製造する条件として、焼成条件が重要であることがわかる。低温では粒子径が小さく触媒間抵抗が低すぎる。また、高温焼成では触媒粒子の焼結・成長が過度となり触媒間抵抗の高い触媒となる。また、セリア粉末Ａ、Ｂ、Ｃは粒径の相違する原料であるが、触媒とするときには適切な焼成条件を設定することで、触媒粒子径を調整することが可能であり好適な触媒間抵抗率の触媒層を形成できる。 And it turns out that a calcination condition is important as conditions for manufacturing these suitable catalysts. At low temperatures, the particle size is small and the inter-catalyst resistance is too low. Further, high-temperature firing results in excessive sintering and growth of the catalyst particles, resulting in a catalyst having high inter-catalyst resistance. Ceria powders A, B, and C are raw materials having different particle diameters, but when used as a catalyst, it is possible to adjust the catalyst particle diameter by setting appropriate firing conditions, and suitable inter-catalyst resistance. Rate catalyst layer.
第２実施形態：ここでは、支持体上の担体のボリュームを変更した触媒を複数製造し、その触媒間抵抗率、触媒活性を評価した。触媒の製造は、第１実施形態と同じ支持体を用意し、担体の塗布量を１００ｇ／Ｌから４００ｇ／Ｌの間で調整した。その後、第１実施形態と同様にしてＲｈを担持し、１２０℃で３０分乾燥後に６００℃で３０分焼成処理し触媒層を形成して触媒を製造した。そして、評価試験を行った。この結果を表２に示す。 Second Embodiment : Here, a plurality of catalysts having different carrier volumes on the support were produced, and the inter-catalyst resistivity and catalytic activity were evaluated. For the production of the catalyst, the same support as in the first embodiment was prepared, and the coating amount of the carrier was adjusted between 100 g / L and 400 g / L. Thereafter, Rh was supported in the same manner as in the first embodiment, dried at 120 ° C. for 30 minutes, and then calcined at 600 ° C. for 30 minutes to form a catalyst layer to produce a catalyst. And the evaluation test was done. The results are shown in Table 2.
この結果から担体のボリュームも触媒間抵抗率に影響を及ぼし、触媒活性も変化することがわかる。具体的には、担体量は１００ｇ／Ｌだと触媒間抵抗率が高く、溶損が発見された。触媒活性も低かった。好適な担体量は、１５０ｇ／Ｌ以上であるが、４００ｇ／Ｌで触媒間抵抗率は最小となるものの転化率が低下している。 From this result, it can be seen that the volume of the carrier also affects the inter-catalyst resistivity, and the catalytic activity also changes. Specifically, when the carrier amount was 100 g / L, the inter-catalyst resistivity was high, and a melting loss was found. The catalytic activity was also low. The preferred amount of the carrier is 150 g / L or more, but the conversion ratio is lowered although the inter-catalyst resistivity is minimized at 400 g / L.
第３実施形態：ここでは、支持体に形成した金属膜の効果について確認した。第１実施形態と同様のセラミックハニカム支持体を用意し、金属膜の形成を行うことなく触媒層を形成した（担体はセリアＡ）。触媒層形成の焼成は、６００℃、８００℃とした（第１実施形態のＮｏ．２とＮｏ．６に相当する）。そして、同様に評価試験を行った。この結果を表３に示す。 Third Embodiment : Here, the effect of the metal film formed on the support was confirmed. A ceramic honeycomb support similar to that in the first embodiment was prepared, and a catalyst layer was formed without forming a metal film (the carrier was ceria A). The baking for forming the catalyst layer was 600 ° C. and 800 ° C. (corresponding to No. 2 and No. 6 of the first embodiment). And the evaluation test was done similarly. The results are shown in Table 3.
表３から、金属膜の形成は触媒間抵抗率を適正にする上で有効である。Ｎｏ．１５の触媒は、Ｎｏ．１４（第１実施形態のＮｏ．２）と同じ条件で触媒層を形成したものであるが、触媒間抵抗率が高く、高電場負荷の際に溶損が生じた。 From Table 3, the formation of the metal film is effective in making the inter-catalyst resistivity appropriate. No. The catalyst of No. 15 14 (No. 2 in the first embodiment), the catalyst layer was formed under the same conditions, but the inter-catalyst resistivity was high, and erosion occurred during high electric field loading.
第４実施形態：ここでは、担体の種類（材質）として様々な混合伝導性セラミックを使用し複数種の触媒を製造した。使用した担体は、セリア単独の他、セリア／アルミナ混合酸化物のような混合酸化物の他、セリアにプラセオジムが一部固溶したセリア／酸化プラセオジム／酸化ランタン混合酸化物等を使用した。担体の塗布量は２００ｇ／Ｌとし、ロジウム担持量は２ｇ／Ｌとした。焼成温度は５００℃とした。そして、各触媒について、触媒層の粒子径測定をした後、第１実施形態と同様の手法でメタン転化率を評価した。その結果を表４に示す。 Fourth Embodiment : Here, a plurality of types of catalysts were manufactured using various mixed conductive ceramics as the type (material) of the support. As the carrier used, in addition to ceria alone, a mixed oxide such as ceria / alumina mixed oxide, ceria / praseodymium oxide / lanthanum oxide mixed oxide in which praseodymium is partly dissolved in ceria, and the like were used. The coating amount of the carrier was 200 g / L, and the rhodium carrying amount was 2 g / L. The firing temperature was 500 ° C. And about each catalyst, after measuring the particle diameter of a catalyst layer, the methane conversion rate was evaluated by the method similar to 1st Embodiment. The results are shown in Table 4.
この試験から、担体として各種のイオン・電子混合伝導性セラミックを用いることで、電場印加による活性向上効果があることが再確認できた。本実施形態の触媒は、第１実施形態の触媒よりもロジウム量を増大させたことにより電場印加がない場合であっても比較的高活性を示すが、ここに１０Ｗ前後の電場を印加したことで更に高活性を示し６０％以上のメタン転化率を示すものであった。また、担体全体がイオン・電子混合伝導性セラミックとすることは必須ではない。アルミナのような絶縁担体を混合した担体であっても、イオン・電子混合伝導性セラミックとの混合により電場触媒として機能し得る（Ｎｏ．１７）。 From this test, it was reconfirmed that there was an activity improvement effect by applying an electric field by using various ion / electron mixed conductive ceramics as a carrier. The catalyst of this embodiment shows a relatively high activity even when no electric field is applied by increasing the amount of rhodium as compared with the catalyst of the first embodiment, but an electric field of about 10 W was applied here. And showed a higher activity and a methane conversion rate of 60% or more. In addition, it is not essential that the entire carrier is an ion / electron mixed conductive ceramic. Even a carrier in which an insulating carrier such as alumina is mixed can function as an electric field catalyst by mixing with an ion / electron mixed conductive ceramic (No. 17).
本発明は、電場触媒という電気エネルギーのアシストにより活性向上を図る新しい分野の触媒に関し、その活性向上の機構と溶損等のリスクとの関係を明らかにするものである。本発明によれば、効率的電場触媒を適用して、水蒸気改質反応等の各種反応プロセスの効率化を図ることができる。 The present invention relates to a catalyst in a new field for improving the activity by assisting electric energy, which is an electric field catalyst, and clarifies the relationship between the mechanism for improving the activity and the risk of melting damage and the like. According to the present invention, an efficient electric field catalyst can be applied to improve efficiency of various reaction processes such as a steam reforming reaction.
Claims (7)
前記触媒層は、イオン・電子混合伝導性セラミックからなる担体粒子に触媒金属を担持させてなる触媒粒子を焼結して形成されるものであり、
前記電極間で測定される４５０℃における触媒間抵抗率が５０Ω・ｍ以上２７０Ω・ｍ以下である水蒸気改質用触媒。 A catalyst for steam reforming , wherein a catalyst layer is formed on a support having a honeycomb structure made of an insulating material, an electrode is brought into contact with the support and / or the catalyst layer, and an electric field is applied to promote the reaction,
The catalyst layer is formed by sintering catalyst particles in which a catalyst metal is supported on carrier particles made of an ion / electron mixed conductive ceramic,
A steam reforming catalyst having an inter-catalyst resistivity at 450 ° C. of 50 Ω · m to 270 Ω · m measured between the electrodes.
前記触媒として、請求項１〜請求項６のいずれかに記載の水蒸気改質用触媒を使用し、前記触媒に電場を印加して反応を進行させる水蒸気改質方法。
In a steam reforming method of producing hydrogen by a steam reforming reaction by reacting a gas containing hydrocarbon and steam in the presence of a catalyst,
A steam reforming method using the steam reforming catalyst according to any one of claims 1 to 6 as the catalyst, and applying an electric field to the catalyst to advance the reaction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015215720A JP6444289B2 (en) | 2015-11-02 | 2015-11-02 | Catalyst that can be activated by electric field application, and steam reforming method using the catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015215720A JP6444289B2 (en) | 2015-11-02 | 2015-11-02 | Catalyst that can be activated by electric field application, and steam reforming method using the catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017087088A JP2017087088A (en) | 2017-05-25 |
| JP6444289B2 true JP6444289B2 (en) | 2018-12-26 |
Family
ID=58769822
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2015215720A Active JP6444289B2 (en) | 2015-11-02 | 2015-11-02 | Catalyst that can be activated by electric field application, and steam reforming method using the catalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6444289B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2019206453A (en) * | 2018-05-29 | 2019-12-05 | Ｊｆｅエンジニアリング株式会社 | Reforming device and reforming method for by-product gas of steel plant |
| WO2023085275A1 (en) * | 2021-11-09 | 2023-05-19 | 株式会社村田製作所 | Electrocatalyst and method for reforming gas using same |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013189884A (en) * | 2012-03-13 | 2013-09-26 | Nissan Motor Co Ltd | Reformed gas supply device |
| JP2015044176A (en) * | 2013-08-29 | 2015-03-12 | 株式会社デンソー | Hydrogen generation catalyst body |
-
2015
- 2015-11-02 JP JP2015215720A patent/JP6444289B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2017087088A (en) | 2017-05-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Liu et al. | An oxygen evolution catalyst on an antimony doped tin oxide nanowire structured support for proton exchange membrane liquid water electrolysis | |
| Zhou et al. | Electrochemical performance of silver-modified Ba0. 5Sr0. 5Co0. 8Fe0. 2O3− δ cathodes prepared via electroless deposition | |
| JP6001793B2 (en) | Method for producing fuel cell catalyst | |
| WO2015033989A1 (en) | Production method for electrode for electrolysis | |
| WO2013187976A1 (en) | Bi-functional catalysts for oxygen reduction and oxygen evolution | |
| JP2014062476A (en) | Composite material, electrode film and manufacturing method thereof, electrode terminal and manufacturing method thereof, base material and manufacturing method thereof, and joint material and manufacturing method of base material in which division body is joined by joint material | |
| JP3981418B2 (en) | Electrode structure for solid state electrochemical devices | |
| Bernsmeier et al. | Highly active binder-free catalytic coatings for heterogeneous catalysis and electrocatalysis: Pd on mesoporous carbon and its application in butadiene hydrogenation and hydrogen evolution | |
| CN108475791A (en) | Catalyst | |
| JP6444289B2 (en) | Catalyst that can be activated by electric field application, and steam reforming method using the catalyst | |
| JP2018098196A (en) | Electrode catalyst for fuel cell | |
| WO2014046196A1 (en) | Anode support body for solid oxide fuel cell, anode supported-type half cell, anode supported-type solid oxide fuel cell single cell, and method for producing anode supported-type half cell | |
| Price et al. | Preparation and testing of metal/Ce0. 80Gd0. 20O1. 90 (metal: Ni, Pd, Pt, Rh, Ru) Co-impregnated La0. 20Sr0. 25Ca0. 45TiO3 anode microstructures for solid oxide fuel cells | |
| Jeon et al. | Metal-oxide nanocomposite catalyst simultaneously boosts the oxygen reduction reactivity and chemical stability of solid oxide fuel cell cathode | |
| Wei et al. | A sulfite/air fuel cell with alkali and sulfuric acid byproducts: bifunctional electrocatalyst for sulfite oxidation and ORR activity | |
| Hufnagel et al. | Carbon-templated conductive oxide supports for oxygen evolution catalysis | |
| JP4759507B2 (en) | Fuel cell electrode catalyst and fuel cell using the same | |
| Keech et al. | Synthesis and performance of sol-gel prepared Ni-YSZ cermet SOFC anodes | |
| RU2713189C2 (en) | Tubular solid oxide electrochemical cell with bearing electrode | |
| JP2020517044A (en) | Anode for solid oxide fuel cell | |
| Lim et al. | Characterization of core-shell structured Ni@ GDC anode materials synthesized by ultrasonic spray pyrolysis for solid oxide fuel cells | |
| JP2004209468A (en) | Electrode catalyst for oxygen reduction, and gas diffusion electrode | |
| US8980786B2 (en) | Metal oxide-platinum compound catalyst and method for producing same | |
| Hanifi et al. | Development of redox resistant fully infiltrated tubular SOFCs | |
| CN114984864B (en) | High-energy-efficiency low-carbon-emission internal electric heating fixed bed hydrogen production reactor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20171121 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20180704 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20180823 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20181009 |
|
| 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: 20181029 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20181127 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6444289 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313117 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |