論文 - 松根 英樹
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Takenaka S., Tsukamoto T., Matsune H., Kishida M.
Catalysis Science and Technology 3 ( 10 ) 2723 - 2731 2013年10月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Catalysis Science and Technology
Carbon nanotube-supported Pd catalysts (Pd/CNT) as the cathode for polymer electrolyte fuel cells (PEFCs) were modified with various transition metals (Fe, Co, Ni and Cu) to improve their catalytic activity for the oxygen reduction reaction (ORR). Modification with these transition metals enhanced the activity of Pd/CNT for the ORR, especially the activity of Pd-Co/CNT, which was 2 times higher than that of Pd/CNT. X-ray diffraction and X-ray absorption spectroscopy indicated that the metal species in Pd-Co/CNT was mainly present as a Pd-Co alloy, which acts as catalytically active sites for the ORR. However, the Pd-Co/CNT catalysts were rapidly deactivated for the ORR in 0.1 M HClO 4 electrolyte due to the dissolution and diffusion of metal species out of the catalysts. Pd-Co/CNT was covered with silica layers with a thickness of a few nanometers, which prevented the diffusion of Co and Pd species into the HClO4 electrolyte. Thus, silica-coated Pd-Co/CNT catalysts exhibited high activity for the ORR and excellent durability under severe cathode conditions. © 2013 The Royal Society of Chemistry.
DOI： 10.1039/c3cy00446e
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Takenaka S., Iga A., Park K., Tanabe E., Matsune H., Kishida M.
Applied Catalysis A: General 450 211 - 221 2013年1月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Applied Catalysis A: General
Fishbone-typed carbon nanofibers (CNFs) that were formed by methane decomposition over silica-supported Ni catalysts were used as catalytic supports for Pt or Pt-Co alloy nanoparticles. The treatment of CNFs with concentrated HNO3 led to the formation of porous structures as well as to the introduction of oxygen-containing functional groups. Pt metal particles of a few nanometers in diameter could be stabilized on the CNFs treated with HNO 3 and showed a high tolerance to sintering at high temperatures, whereas Pt metal particles supported on the CNFs without any treatment were seriously aggregated at high temperatures. The porous structures and functional groups in the CNFs worked as anchoring sites for Pt metal nanoparticles. Thus, Pt-Co alloy particles of a few nanometers in diameter could be prepared by using the CNF support since the CNFs inhibited the sintering of the alloy particles during the treatment at high temperatures to allow for alloy formation. © 2012 Elsevier B.V.
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Takenaka S., Miyata H., Tsukamoto T., Matsune H., Kishida M.
ECS Transactions 50 ( 2 ) 1715 - 1722 2012年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：ECS Transactions
We have previously demonstrated that silica-coated Pd cathode catalysts show high durability under severe cathode conditions in polymer electrolyte fuel cells (PEFCs), while Pd catalysts without silica-coating seriously deactivate under the same conditions due to the dissolution of Pd metal. However, the activity of silica-coated Pd catalysts for the oxygen reduction reaction (ORR) was inferior to that of Pt catalysts used in state of the art PEFCs. In the present study, the ORR activity of Pd catalysts was improved by addition of Cu. Cu-added Pd catalyst prepared with a conventional impregnation method using mixed aqueous solutions of PdCl2 and Cu(NO3)2 had an ORR activity twice that of Pd catalysts. XRD and XAFS studies showed alloy formation between Pd and Cu. Thus, Pd-Cu alloys showed higher activity for the ORR compared with Pd metal. © The Electrochemical Society.
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Takenaka S., Arike T., Matsune H., Kishida M.
Applied Catalysis B: Environmental 125 358 - 366 2012年8月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Applied Catalysis B: Environmental
TiO 2 nanoparticles were deposited on carbon nanotubes (CNTs) to improve their photocatalytic activity. The outer surface of the CNTs could be uniformly covered with TiO 2 nanoparticles using the hydrolysis of titanium tetraisopropoxide (Ti(O iPr) 4) in the presence of urea or glycine amide. The urea and glycine amide acted as linker molecules between the TiO 2 nanoparticles and the CNT surfaces. The TiO 2-coated CNTs showed a higher catalytic activity for the photodegradation of organic molecules than TiO 2 alone. The addition of the CNTs to the TiO 2 photocatalytic system retarded the recombination of the electron-hole pairs generated in the photo-irradiated TiO 2. When Pt metal particles were inserted in the cavities of the CNTs in the TiO 2-coated CNT catalyst system, further improvements in the photocatalytic activity were observed. The TiO 2-coated CNTs with Pt metal particles displayed a unique catalytic performance in the photocatalytic degradation of organic impurities in water. © 2012 Elsevier B.V.
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Mardwita, Matsune H., Takenaka S., Kishida M.
Journal of Chemical Engineering of Japan 45 ( 7 ) 493 - 497 2012年7月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Chemical Engineering of Japan
We investigated the addition of chromium to alumina-supported Pt catalysts and its effect on catalytic activity in methane combustion. The Pt and Cr binary alumina-supported catalysts exhibited much higher activity than those without Cr. Alumina-supported Cr catalysts contain two chromium species, Cr 3+ and Cr 6+. From XPS analysis, it was found that more Cr 6+ species existed in the binary catalysts than in the single alumina-supported Cr catalysts. Pt species in the binary catalysts may promote Cr oxidation. Since Cr 6+ species are known to be more active than Cr3ff species in oxidation reactions, the increase in Cr 6+ in the binary catalysts may contribute to their higher activity compared with the Pt/Al 2O 3 catalyst. © 2012 The Society of Chemical Engineers, Japan.
DOI： 10.1252/jcej.12we025
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Takenaka S., Arike T., Miyazaki T., Matsune H., Kishida M.
Chemistry Letters 41 ( 6 ) 617 - 619 2012年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Chemistry Letters
TiO 2 nanoparticles were deposited on carbon nanotubes (CNTs) for improvement of their photocatalytic activity. CNTs could be uniformly covered with TiO 2 nanoparticles by the hydrolysis of titanium tetraisopropoxide in the presence of urea. Urea worked as linker molecules between the CNT surface and the TiO 2 nanoparticles. The resultant TiO 2CNT composites showed a high catalytic activity for photodegradation of organic molecules. © 2012 The Chemical Society of Japan.
DOI： 10.1246/cl.2012.617
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Takenaka S., Matsumori H., Matsune H., Kishida M.
Applied Catalysis A: General 409-410 248 - 256 2011年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Applied Catalysis A: General
Carbon black-supported Pt (Pt/CB) catalysts that have been used at the cathode in state of the art polymer electrolyte fuel cell (PEFC) were covered with silica layers to improve the durability of the Pt catalysts under PEFC cathode conditions. The durability of silica-coated Pt/CB to potential cycling between 0.6 and 0.9 V (vs. reversible hydrogen electrode (RHE)) was strongly dependent on the thickness of the silica layers, i.e., the durability of Pt/CB improved after coverage with thick silica layers. However, the coverage of the whole surface of the Pt/CB catalysts with silica layers produced electrochemically inactive Pt catalysts. Silica-coated Pt/CB catalysts with an optimal silica layer thickness showed similar activity for the oxygen reduction reaction compared to Pt/CB catalysts without a silica coating, and they had excellent durability at the cathode in a PEFC single cell. Coverage with silica layers improved the durability of the Pt/CB cathode catalysts without a decrease in the catalytic activity for the oxygen reduction reaction. © 2011 Elsevier B.V. All rights reserved.
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Takenaka S., Miyamoto H., Susuki N., Matsune H., Kishida M.
ECS Transactions 41 ( 1 ) 2305 - 2312 2011年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：ECS Transactions
Carbon nanotube-supported Pd catalyst (Pd/CNT) was covered with silica layers a few nanometers thick by successive hydrolysis of 3- aminopropyltriethoxysilane (APTES) and tetraethoxysilane (TEOS) to improve the durability of the Pd catalyst under cathode conditions of polymer electrolyte fuel cells (PEFCs). The coverage with silica layers resulted in the improvement of durability of Pd/CNT during the potential cycling between 0.05 and 1.20 V (vs. RHE) in aqueous HClO 4 electrolyte. The catalytic activity and durability of silica-coated Pd/CNT strongly depended on silica layer thickness in the catalysts. The coverage with thicker silica layers improved the durability of Pd/CNT but the catalytic activity of the catalysts for the oxygen reduction reaction became lower with silica layer thickness. The coverage of Pd/CNT with silica layers of ca. 3 nm thickness is preferable from a viewpoint of the catalytic activity and durability. © 2011 ECS - The Electrochemical Society.
DOI： 10.1149/1.3635764
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Catalytic performance of pt metal particles at the tips of carbon nanotubes 査読あり
Takenaka S., Iguchi T., Tanabe E., Matsune H., Kishida M.
Catalysis Letters 141 ( 6 ) 821 - 825 2011年6月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Catalysis Letters
The catalytic performance of Pt metal at the tips of carbon nanotubes (CNT@Pt), which was prepared by ethylene decomposition over Pt/MgO, was compared with that of Pt metal on the outer surface of CNT (Pt/CNT). CNT@Pt showed excellent catalytic performance toward the hydrogenation of α, β-unsaturated aldehydes to unsaturated alcohols, which was similar to that of Pt/CNT and resulted from a strong interaction between Pt metal and the CNT. Graphical Abstract: Pt metal particles at the tips of CNTs showed excellent activity for the selective hydrogenation of α, β-unsaturated aldehydes to unsaturated alcohols similarly to Pt metal particles supported on the outer surface of CNTs.[Figure not available: see fulltext.] © 2011 Springer Science+Business Media, LLC.
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Takenaka S., Susuki N., Miyamoto H., Tanabe E., Matsune H., Kishida M.
Journal of Catalysis 279 ( 2 ) 381 - 388 2011年4月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Catalysis
Pd metal supported on carbon nanotubes (Pd/CNT) for use as a cathode catalyst in polymer electrolyte fuel cells was covered with silica layers a few nanometers thick to improve the durability of the catalyst under severe cathode conditions. The silica-coated Pd/CNT cathode catalyst showed similar activity for the oxygen reduction to Pd/CNT despite coverage of the Pd metal with a silica insulator. In addition, the silica-coated Pd/CNT was highly durable during potential cycling between 0.05 and 1.20 V (vs. reversible hydrogen electrode) in aqueous HClO4 while Pd/CNT suffered serious deactivation under the same conditions. The silica layers in the silica-coated Pd/CNT prevent the diffusion of dissolved Pd species from the Pd metal out of the layers. Therefore, silica-coated Pd/CNT was highly durable under the cathode conditions. Furthermore, coverage of Pd/CNT with silica layers inhibited the two-electron reduction of oxygen to H2O2. © 2011 Elsevier Inc. All rights reserved.
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Takenaka S., Susuki N., Miyamoto H., Tanabe E., Matsune H., Kishida M.
Chemical Communications 46 ( 47 ) 8950 - 8952 2010年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Chemical Communications
Pd cathode catalysts for polymer electrolyte fuel cells have been covered with silica layers a few nanometres thick. The silica-coated Pd catalysts showed high activity and excellent durability for the oxygen reduction under the severe cathode conditions of PEFCs, while Pd catalysts without silica-coating were seriously deactivated under the same conditions. The coverage of Pd metal with silica prevents the diffusion of Pd species out of the silica layers. © 2010 The Royal Society of Chemistry.
DOI： 10.1039/c0cc04055j
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Takenaka S., Hirata A., Tanabe E., Matsune H., Kishida M.
Journal of Catalysis 274 ( 2 ) 228 - 238 2010年9月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Catalysis
Pt-based alloy catalysts such as carbon black-supported Pt-Co catalysts (Pt-Co/CB) are used in the oxygen reduction reaction in polymer-electrolyte fuel cells (PEFCs) and are generally treated at high temperatures to allow for alloy formation. However, treatment of these catalysts at high temperatures results in serious aggregation of alloy particles. In this study, a Pt-Co/CB catalyst was covered with silica layers to inhibit the aggregation of alloy particles during treatment of the catalyst at high temperature for alloy formation. Coverage of Pt-Co/CB with silica promoted Pt-Co alloy formation with a high alloying degree and a small particle size, whereas the alloying degree of Pt-Co alloys in Pt-Co/CB without silica-coating was low, and these alloy particles were seriously aggregated during treatment at high temperature. These silica-coated Pt-Co/CB catalysts showed high activity and excellent durability for the oxygen reduction reaction. © 2010 Elsevier Inc. All rights reserved.
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Arike T., Takenaka S., Matsune H., Kishida M.
Bulletin of the Chemical Society of Japan 83 ( 8 ) 953 - 959 2010年8月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Bulletin of the Chemical Society of Japan
Carbon nanotube-supported Ru (Ru/CNT) catalysts were covered with silica layers to inhibit the aggregation of Ru particles as well as the detachment of Ru particles from the CNTs during catalytic reactions. Coverage of the Ru/CNT with silica was performed by the successive hydrolysis of 3- aminopropyltriethoxysilane and tetraethoxysilane in the presence of CNT-supported Ru metal precursors, followed by reduction with hydrogen at 623 K. The diameter of the Ru particles in the silica-coated Ru/CNT ranged from 1 to 3 nm. The Ru particles and the CNTs in the silica-coated catalysts were uniformly covered with silica layers a few nanometers thick. The size of the Ru particles in the silica-coated catalysts did not change appreciably after treatment at 873 K, while the metal particles in the Ru/CNT were seriously aggregated after treatment at 873 K. The silica-coated Ru/CNT catalyzed the CO hydrogenation and the 1-hexene hydrogenation, despite the coverage of Ru particles with silica. In addition, the silica-coated Ru catalysts showed high durability toward Ru detachment from the CNTs during the repeated hydrogenation of 1-hexene, whereas the catalysts without silica layers were deactivated because of Ru detachment. Therefore, coverage of the Ru/CNT catalysts with silica layers prevented the deactivation of the catalysts. © 2010 The Chemical Society of Japan.
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Chemical synthesis of silver nanowires using N,N-dimethyldodecylamine oxide 査読あり
Matsune H., Kuramitsu Y., Takenaka S., Kishida M.
Chemistry Letters 39 ( 7 ) 717 - 719 2010年7月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Chemistry Letters
This paper describes a new approach for the synthesis of uniform silver nanowires (AgNWs) using zwitterionic amphiphile, N,N-dimethyldodecylamine oxide (DDAO). Heating of AgCl and DDAO in the presence of silver nanoparticles at 135°C for 3 h produces longer AgNWs. The DDAO serves as a source of both a reducing and capping agent in the process. © 2010 The Chemical Society of Japan.
DOI： 10.1246/cl.2010.717
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Takenaka S., Hirata A., Matsune H., Kishida M.
Chemistry Letters 39 ( 5 ) 458 - 459 2010年5月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Chemistry Letters
Carbon-supported Pt-Co catalyst for the oxygen reduction reaction was covered with silica layers to inhibit sintering of the metal particles. Coverage of the Pt-Co catalyst with silica layers promoted the formation of alloys with small diameters during treatment at 973 K. The silica-coated Pt-Co electrocatalyst showed a large electrochemically active surface area (ECSA) and excellent durability. © 2010 The Chemical Society of Japan.
DOI： 10.1246/cl.2010.458
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Matsumori H., Takenaka S., Matsune H., Kishida M.
Applied Catalysis A: General 373 ( 1-2 ) 176 - 185 2010年1月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Applied Catalysis A: General
Multi-walled carbon nanotube-supported Pt metal particle (Pt/CNT) catalysts were covered with silica layers with different thickness and density. In the present study, the Pt/CNT covered with silica layers (SiO2/Pt/CNT) was prepared by the successive hydrolysis of 3-aminopropyl-triethoxysilane (APTS) and tetraethoxysilane (TEOS). The thickness of silica layers in SiO2/Pt/CNT could be controlled by varying the concentration of silica sources during the preparation of SiO2/Pt/CNT. The density of silica layers in SiO2/Pt/CNT was changed by varying the treatment temperature for the catalysts as well as by adjusting the pH for the hydrolysis of silica sources during the preparation of the catalysts. The catalytic performance of these SiO2/Pt/CNT as cathode catalysts in polymer electrolyte fuel cells was examined. Pt/CNT covered with silica layers of adequate thickness (ca. 6 nm) and high density had a high electrochemically active surface area as well as excellent durability. Dense silica layers in SiO2/Pt/CNT prevented the diffusion of cationic Pt species dissolved from Pt metal particles out of the catalysts. © 2009 Elsevier B.V. All rights reserved.
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Nakagawa K., Takenaka S., Matsune H., Kishida M.
Studies in Surface Science and Catalysis 175 793 - 796 2010年
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Studies in Surface Science and Catalysis
Silica-coated Pt-Ni alloys were prepared using a water-in-oil-type microemulsion. The silica-coated Pt-Ni alloys prepared without thermal treatment decomposed ethylene to form nanocomposites of carbon nanoflbers. © 2010 Elsevier B.V. All rights reserved.
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Effect of the lateral growth rate on wood properties in fast-growing hardwood species 査読あり
Kojima M., Yamamoto H., Okumura K., Ojio Y., Yoshida M., Okuyama T., Ona T., Matsune K., Nakamura K., Ide Y., Marsoem S., Sahri M., Hadi Y.
Journal of Wood Science 55 ( 6 ) 417 - 424 2009年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Journal of Wood Science
We investigated the feasibility of using several fast-growing tropical or subtropical hardwood species for timber production by measuring key wood qualities in relationship to the high rates of lateral growth. The trees tested were sampled from even-aged plantations of Acacia mangium, A. auriculiformis, hybrid Acacia (A. mangium × A. auriculiformis), Eucalyptus grandis, E. globulus, and Paraserianthes falcataria (Solomon and Java origin) that had already reached commercial harvesting age. The released strain of the surface growth stress (RS), xylem density (XD), microfibril angle (MFA), and fiber length (FL) were measured at the outermost part of the xylem at breast height in each tree. Results were then compared to the lateral growth rate (radius/age) at breast height, which provides a relative indicator of the amount of tree growth per year. Our findings indicated that RS was constant, regardless of lateral growth rate in each species. Similar results were observed for XD, MFA, and FL, with a few exceptions, suggesting that high growth rates do not intrinsically affect the wood properties of fast-growing tropical or subtropical species that have reached harvesting age. However, special attention must be paid to patterns of xylem maturation when developing plantations of such species. © The Japan Wood Research Society 2009.
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Excellent durability of carbon-supported Pt cathode catalysts covered with silica layers 査読あり
Matsumori H., Takenaka S., Matsune H., Kishida M.
ECS Transactions 25 ( 1 PART 1 ) 689 - 696 2009年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：ECS Transactions
Multi-walled carbon nanotube-supported platinum electrocatalysts (Pt/CNT) for cathode in polymer electrolyte fuel cells were covered with silica layers (SiO2/Pt/CNT) in order to improve the durability. SiO 2/Pt/CNT had a high catalytic activity in spite of uniform coverage of Pt metal with silica which was an insulator. The catalytic activity of SiO2/Pt/CNT did not change appreciably during the durability test (repeated potential cycling between 0.05 and 1.20V vs. RHE), whereas Pt/CNT was seriously deactivated. Silica layer which enveloped Pt metal particles in SiO2/Pt/CNT prevented the agglomeration of Pt metal particles as well as the growth of Pt metal particles in size through dissolution and redeposition of Pt metal. ©The Electrochemical Society.
DOI： 10.1149/1.3210620
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Dynamic Motion of Single Cells and its Relation to Cellular Properties 査読あり
Matsune H., Sakurai D., Hirukawa A., Takenaka S., Kishida M.
Molecular Nano Dynamics: Vol. I: Spectroscopic Methods and Nanostructures / Vol. II: Active Surfaces, Single Crystals and Single Biocells 2 689 - 702 2009年11月
記述言語：日本語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Molecular Nano Dynamics: Vol. I: Spectroscopic Methods and Nanostructures / Vol. II: Active Surfaces, Single Crystals and Single Biocells