Faculty Profiles - NAGAOKA Katsutoshi

Papers - NAGAOKA Katsutoshi

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Dual Lewis Acidic/Basic Pd0.5Ru0.5-Poly(N-vinyl-2-pyrrolidone) Alloyed Nanoparticle: Outstanding Catalytic Activity and Selectivity in Suzuki-Miyaura Cross-Coupling Reaction Reviewed

Md. Shahajahan Kutubi, Katsutoshi Sato, Kenji Wada, Tomokazu Yamamoto, Syo Matsumura, Kohei Kusada, Hirokazu Kobayashi, Hiroshi Kitagawa, Katsutoshi Nagaoka

CHEMCATCHEM Vol. 7 ( 23 ) page： 3887 - 3894 2015.12

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

This article anticipates the development of dual Lewis acidic/basic alloyed nanoparticle (NP) of poly(N-vinyl-2-pyrrolidone)stabilized Pd0.5Ru0.5 solid solution, revealing equivalent Pd delta+ and Ru-delta on the NP surface. This unsupported NP disclosed excellent catalytic efficiency with high turnover frequency, 15000 h(-1) in Suzuki-Miyaura cross-coupling under notable drop of both Pd loading (0.08 mol%) and time (5 min) in air, attributed for its bifunctional acidic/basic modes. The bifunctional modes exposed the most interesting new reaction mechanism ascribed by the inductive effects of p-substituents in arylboronic acid, accelerated reactivity by electron-withdrawing group, revealing an opposite reactivity trend relative to other Pd-based catalysts. Besides, the significant drops of Pd loading and reaction time impeded the metal leaching associated with no changes in NP surface composition/structure after the 3rd cycle (>99% efficiency), revealing a line-up for this NP in the environmental sustainability.

DOI： 10.1002/cctc.201500758

Other Link： http://orcid.org/0000-0003-1774-1537

Development of Efficient Cold-start Process for Oxidative Reforming of n-Butane for Fuel Cell Applications Reviewed Open Access

Katsutoshi Nagaoka, Katsutoshi Sato

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE Vol. 58 ( 5 ) page： 274 - 284 2015.9

Language：English Publishing type：Research paper (scientific journal) Publisher：JAPAN PETROLEUM INST

Efficient cold-start process of hydrogen production by oxidative reforming (OR) of hydrocarbon was developed using Rh catalyst supported on carriers with redox properties. In this process, the heat generated by re-oxidation of reduced catalyst rapidly heats the catalyst from ambient temperature to the catalytic auto-ignition temperature of the OR. OR was triggered at ambient temperature over Rh/CeO2 after reduction at 873 K, but not over Rh catalysts supported on Pr6O11 and Tb4O7, oxides of rare earth elements with redox characters like cerium. Over the latter catalysts, reduction of the carrier occurred at lower temperatures than over CeO2, but the reduced oxides were not re-oxidized at ambient temperature. Our results emphasized that re-oxidation as well as reduction of the catalyst are the key characteristics of the carrier for triggering OR at ambient temperature. With the use of Rh/Ce0.5Zr0.5O2 with excellent redox properties at low temperature, triggering OR of hydrocarbons at ambient temperature was achieved even under non-adiabatic conditions, where heat losses occur, over the catalyst after reduction at 373 K and after in-situ reduction by hydrogen formed during the OR. This new catalytic process is expected to be useful for the development of self-sufficient reforming processes for a new generation of fuel cells.

DOI： 10.1627/jpi.58.274

Other Link： http://orcid.org/0000-0003-1774-1537

Influence of basic dopants on the activity of Ru/Pr6O11 for hydrogen production by ammonia decomposition Reviewed Open Access

Katsutoshi Nagaoka, Takaaki Eboshi, Naruhiko Abe, Shin-ichiro Miyahara, Kyoko Honda, Katsutoshi Sato

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Vol. 39 ( 35 ) page： 20731 - 20735 2014.12

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Basic oxides such as alkali metal oxides, alkaline earth metal oxides, and rare earth oxides were added to Ru/Pr6O11, and the activity of the catalysts with respect to hydrogen production by ammonia decomposition was investigated. Ru/Pr6O11 doped with alkali metal oxides, except for Li2O, achieved higher NH3 conversions than bare Ru/Pr6O11 center dot Cs2O, the most basic of the alkali metal oxides, was the most effective dopant. In contrast, other dopants with lower basicity than the alkali metal oxides achieved lower NH3 conversions than bare Ru/Pr6O11. Changing the Cs/Ru molar ratio revealed that the best Cs/Ru ratio was 0.5-2; the reaction was effectively promoted without negative effects from coverage of the Ru surface by the Cs2O. Varying the order of loading the Ru and Cs2O onto Pr6O11 revealed that loading Ru onto Cs2O/Pr6O11 was an effective way to enhance NH3 conversion, and coverage of the Ru surface was reduced. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ijhydene.2014.07.142

Other Link： http://orcid.org/0000-0003-1774-1537

Inhibition of Ammonia Poisoning by Addition of Platinum to Ru/alpha-Al2O3 for Preferential CO Oxidation in Fuel Cells Reviewed

Katsutoshi Sato, Sho Yagi, Shuhei Zaitsu, Godai Kitayama, Yuto Kayada, Kentaro Teramura, Yusaku Takita, Katsutoshi Nagaoka

CHEMSUSCHEM Vol. 7 ( 12 ) page： 3264 - 3267 2014.12

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

In polymer electrolyte fuel cell (PEFC) systems, small amounts of ammonia (NH3) present in the reformate gas deactivate the supported ruthenium catalysts used for preferential oxidation (PROX) of carbon monoxide (CO). In this study, we investigated how the addition of a small amount of platinum to a Ru/alpha-Al2O3 catalyst (Pt/Ru=1:9 w/w) affected the catalyst's PROX activity in both the absence and the presence of NH3 (130 ppm) under conditions mimicking the reformate conditions during steam reforming of natural gas. The activity of undoped Ru/alpha-Al2O3 decreased sharply upon addition of NH3, whereas Pt/Ru/alpha-Al2O3 exhibited excellent PROX activity even in the presence of NH3. Ruthenium K-edge X-ray absorption near-edge structure (XANES) spectra indicated that in the presence of NH3, some of the ruthenium in the undoped catalyst was oxidized in the presence of NH3, whereas ruthenium oxidation was not observed with Pt/Ru/alpha-Al2O3. These results suggest that ruthenium oxidation is retarded by the platinum, so that the catalyst shows high activity even in the presence of NH3.

DOI： 10.1002/cssc.201402583

Other Link： http://orcid.org/0000-0003-1774-1537

Synthesis and catalytic application of PVP-coated Ru nanoparticles embedded in a porous metal-organic framework Reviewed

Masaaki Sadakiyo, Masaru Kon-no, Katsutoshi Sato, Katsutoshi Nagaoka, Hidetaka Kasai, Kenichi Kato, Miho Yamauchi

DALTON TRANSACTIONS Vol. 43 ( 29 ) page： 11295 - 11298 2014.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

A hybrid catalyst consisting of polymer-coated Ru nanoparticles (Ru-PVP, PVP: poly(N-vinyl-2-pyrrolidone)) embedded in a porous metal-organic framework of ZIF-8 (Ru-PVP@ZIF-8) was synthesized by the crystallization of ZIF-8 in a methanol solution of Ru-PVP. The structural properties of Ru-PVP@ZIF-8 were examined by N-2 gas adsorption, infrared spectra, and X-ray powder diffraction measurements. We successfully identified the most appropriate pretreatment conditions for surface activation of the Ru nanoparticles in the catalyst. The pretreated Ru-PVP@ZIF-8 was applied for a CO oxidation reaction with H-2 gas feeds. Ru-PVP@ZIF-8 was found to exhibit higher catalytic activities and higher CO2 selectivity than those observed on a carbon-supported Ru-PVP (Ru-PVP/C), implying that the pores of the ZIF-8 provide a more suitable environment for the reaction with O-2 and CO gases.

DOI： 10.1039/c4dt00996g

Other Link： http://orcid.org/0000-0003-1774-1537

Effect of the Nature of the CeO2 Support of the Rh Catalyst on Triggering the Oxidative Reforming of n-Butane for H2 Production from Ambient Temperature Reviewed

Katsutoshi Sato, Kouhei Adachi, Yusaku Takita, Katsutoshi Nagaoka

CHEMCATCHEM Vol. 6 ( 3 ) page： 784 - 789 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Three Rh catalysts supported on CeO2 with different specific surface areas and redox properties were prepared and evaluated for their ability to trigger the oxidative reforming of n-butane from ambient temperature (approximate to 300K). The reference CeO2 catalysts supplied by the Catalyst Society of Japan (JRC-CEO-1, -3, and -4) were used as supports. Temperature-programmed reduction and O-2 titration measurements over the reduced catalysts indicated that a high number of surface CeO2 sites that were reducible below 573K were present on the Rh/CEO-3 catalyst; this catalyst had the largest specific surface area, and it generated sufficient heat by oxidizing CeO2-x [H(298K)=-368kJ; x=0.5] after H-2 reduction at 773K. Furthermore, the temperature-programmed reactions revealed that forming fine Rh particles on the high surface area of CEO-3 lowers the autoignition temperature (498K) of the oxidative reforming of n-butane because the number of exposed Rh sites initiating reactions between n-butane and O-2 is large. Thus, the Rh/CEO-3 catalyst could trigger the oxidative reforming of n-butane at ambient temperature after H-2 reduction at 773K owing to the heat generated by the spontaneous oxidation of CeO2-x. In contrast, other catalysts could not trigger the reaction after reduction at the same temperature.

DOI： 10.1002/cctc.201300826

Other Link： http://orcid.org/0000-0003-1774-1537

Solid Solution Alloy Nanoparticles of Immiscible Pd and Ru Elements Neighboring on Rh: Changeover of the Thermodynamic Behavior for Hydrogen Storage and Enhanced CO-Oxidizing Ability Reviewed

Kohei Kusada, Hirokazu Kobayashi, Ryuichi Ikeda, Yoshiki Kubota, Masaki Takata, Shoichi Toh, Tomokazu Yamamoto, Syo Matsumura, Naoya Sumi, Katsutoshi Sato, Katsutoshi Nagaoka, Hiroshi Kitagawa

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 136 ( 5 ) page： 1864 - 1871 2014.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

PdxRu1-x solid solution alloy nanoparticles were successfully synthesized over the whole composition range through a chemical reduction method, although Ru and Pd are immiscible at the atomic level in the bulk state. From the XRD measurement, it was found that the dominant structure of PdxRu1-x changes from fcc to hcp with increasing Ru content. The structures of PdxRu1-x nanoparticles in the Pd composition range of 30-70% consisted of both solid solution fcc and hcp structures, and both phases coexist in a single particle. In addition, the reaction of hydrogen with the PdxRu1-x nanoparticles changed from exothermic to endothermic as the Ru content increased. Furthermore, the prepared PdxRu1-x nanoparticles demonstrated enhanced CO-oxidizing catalytic activity; Pd0.5Ru0.5 nanoparticles exhibit the highest catalytic activity. This activity is much higher than that of the practically used CO-oxidizing catalyst Ru and that of the neighboring Rh, between Ru and Pd.

DOI： 10.1021/ja409464g

Other Link： http://orcid.org/0000-0003-1774-1537

Cr3+-Co0.054Ni0.018Mg0.93O Solid-Solution Catalysts for High-Pressure Syngas Production: Effect of Chromium on the Reduction and Catalysis Reviewed

Katsutoshi Nagaoka, Yosuke Abe, Yusaku Hashimoto, Takahiro Ishikawa, Katsutoshi Sato, Yusaku Takita, Toshiya Wakatsuki, Masahiro Kunisu, En Suda, Shin Inamoto

ACS CATALYSIS Vol. 3 ( 7 ) page： 1564 - 1572 2013.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Adding Cr to heat-tolerant Co0.054Ni0.018Mg0.93O solid-solution catalysts for CH4/CO2/H2O reforming at 2.1 M.Pa allowed us to control the key properties determining the behavior of the supported catalysts, such as the reduction degree of the metal, metal particle size, and amount of exposed zerovalent metals. A small load of Cr [Cr/(Co + Ni) = 0.11 mol %] efficiently catalyzed Co2+ and Ni2+ reduction. This catalyst, which had abundant small alloy particles on the support material, resisted coking and oxidative deactivation, even under accelerated deterioration conditions: X-ray photoelectron spectroscopy, X-ray absorption near-edge structure, extended X-ray absorption fine structure, and scanning transmission electron microscopy energy-dispersive X-ray measurements indicated that Cr existed as a trivalent cation in a CrxCo0.054Ni0.018Mg0.93O1+1.5x solid solution, leading to the formation of a divalent cation vacancy and that Cr3+ was abundant on the surface of the catalyst particles after calcination at 1373 K. The Cr3+ destabilized Co2+ and Ni2+ in the solid solution, especially on the surface of the catalyst particles and, thus, promoted Co2+ and Ni2+ reduction. However, excess Cr3+ induced sintering of the catalyst particles, resulting in aggregation of alloy particles and, thus, in an increased risk of coking.

DOI： 10.1021/cs400199b

Other Link： http://orcid.org/0000-0003-1774-1537

Discovery of Face-Centered-Cubic Ruthenium Nanoparticles: Facile Size-Controlled Synthesis Using the Chemical Reduction Method Reviewed

Kohei Kusada, Hirokazu Kobayashi, Tomokazu Yamamoto, Syo Matsumura, Sumi Naoya, Katsutoshi Sato, Katsutoshi Nagaoka, Yoshiki Kubota, Hiroshi Kitagawa

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 135 ( 15 ) page： 5493 - 5496 2013.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

We report the first discovery of pure face-centered-cubic (fcc) Ru nanoparticles. Although the fcc structure does not exist in the bulk Ru phase diagram, fcc Ru was obtained at room temperature because of the nanosize effect. We succeeded in separately synthesizing uniformly sized nanoparticles of both fcc and hcp Ru having diameters of 2-5.5 nm by simple chemical reduction methods with different metal precursors. The prepared fcc and hcp nanoparticles were both supported on gamma-Al2O3, and their catalytic activities in CO oxidation were investigated and found to depend on their structure and size.

DOI： 10.1021/ja311261s

Other Link： http://orcid.org/0000-0003-1774-1537

Monoatomically dispersed Pd/TiO2 catalyst effective for epoxidation of propylene at ambient temperature in the presence of H-2 and O-2 Reviewed

Susumu Hikazudani, Tatsuya Mochida, Naofumi Matsuo, Katsutoshi Nagaoka, Tatsumi Ishihara, Hisayoshi Kobayashi, Yusaku Takita

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL Vol. 358 page： 89 - 98 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The catalytic activity of monoatomically dispersed Pd supported on TiO2 toward propylene epoxidation in the presence of H-2 and O-2 was studied at ambient temperature, and both propylene oxide (PO) and propane were obtained. Short-chain alkanes also reacted but epoxide formation was not observed in those reactions except in the case of isobutane, which formed isobutylene oxide at a low rate. The optimum surface concentration of Pd on TiO2 was 0.005-0.01 atom/nm(2); because the supported amount of Pd is extremely small relative to the surface area of the support, the supported Pd is thought to be monoatomically dispersed. Pd/TiO2 catalysts prepared from a tetraphenylporphyrin-Pd chloride complex showed almost the same product distribution for propylene epoxidation as did catalysts prepared from Pd(NO3)(2). Isotope exchange between H-2 and D-2 proceeded over Pd/TiO2 with a low surface concentration (0.0001 atom-Pd/nm(2)), and chemical potential calculations suggested that H-2 molecules could dissociatively adsorb onto the monoatomically dispersed Pd/TiO2. A PO formation mechanism over the catalyst is proposed on the basis of these results. The results presented here may provide the first clear evidence of catalysis by monoatomically dispersed noble metals. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.molcata.2012.03.001

Other Link： http://orcid.org/0000-0003-1774-1537

Effect of the nature of rhodium catalyst supports on initiation of H-2 production during n-butane oxidative reforming at room temperature Reviewed

Katsutoshi Nagaoka, Katsutoshi Sato, Yusaku Takita

JOURNAL OF CATALYSIS Vol. 287 page： 86 - 92 2012.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

Three rhodium catalysts supported on rare earth oxides with redox properties, Rh/CeO2, Rh/Pr6O11, and Rh/Tb4O7, were tested for their ability to trigger oxidative reforming of n-butane at room temperature. Only Rh/CeO2 triggered the oxidative reforming, owing to the heat generated by the spontaneous oxidation of the CeO2-x species produced by prior reduction of the supported catalyst with H-2. Although the three rare earth oxides were reduced to CeO1.91. Pr2O3, and Tb2O3, respectively, by H-2 at >= 873 K. CeO1.91 was the only reduced oxide that was oxidized upon exposure to O-2 at room temperature. These results indicate that the ability of the reduced oxide support to undergo oxidation at room temperature was crucial for triggering oxidative reforming of n-butane at room temperature. (C) 2011 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcat.2011.12.007

Other Link： http://orcid.org/0000-0003-1774-1537

Mono-atomically dispersed Pd on TiO2 as a catalyst for epoxidation of light olefins at low temperatures in the presence of H-2 and O-2 Reviewed

Susumu Hikazudani, Tatsuya Mochida, Kenshiro Yano, Katsutoshi Nagaoka, Tatsumi Ishihara, Yusaku Takita

CATALYSIS COMMUNICATIONS Vol. 12 ( 15 ) page： 1396 - 1400 2011.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Palladium supported at extremely low loading on TiO2 catalyzed epoxidation of light olefins (except ethylene) in the presence of O-2 and H-2 at ambient temperature. Propylene oxide (PO) was obtained from propylene (1-2% yield; 30-60% selectivity) together with propane. Simple oxidation of H-2 to water was slow, and the ratio of H-2 used for PO formation in the reacted H-2 was 10-25%. A Pd concentration of 0.005-0.01 atom-Pd/nm(2)-TiO2 was optimum for epoxidation, and the major product at 0.02 atom-Pd/nm(2) was acetone. That the distributions for a Pd/TiO2 catalysts prepared from Pd nitrate and from a Pd-tetraphenylporphyrin complex at the same Pd loading were similar suggests that Pd was supported mono-atomically on TiO2. We propose that PO formed via reaction between propylene adsorbed on Pd and an active species derived from reaction of H-2 and O-2 on TiO2 (perhaps center dot OOH). (C) 2011 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.catcom.2011.05.020

Other Link： http://orcid.org/0000-0003-1774-1537

Oxidative Steam Reforming of Ethanol over Supported Ni Catalysts at Relatively Low Temperature Reviewed

Sato Katsutoshi, Ito Akiko, Kawano Kosuke, Takita Yusaku, Nagaoka Katsutohi

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE Vol. 54 ( 5 ) page： 331 - 337 2011.9

Highly Active Cs2O/Ru/Pr6O11 as a Catalyst for Ammonia Decomposition Reviewed

Katsutoshi Nagaoka, Kyoko Honda, Megumi Ibuki, Katsutoshi Sato, Yusaku Takita

CHEMISTRY LETTERS Vol. 39 ( 9 ) page： 918 - 919 2010.9

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

The use of a new catalyst, namely, Cs2O/5 wt % Ru/Pr6O11 (mole ratio of Cs to Ru: 1), in which Ru is supported on strong basic Pr6O11 and the strong basic promoter Cs2O is added, resulted in almost complete NH3 consumption at 673 K and an NH3 conversion of 14% even at temperatures as low as 523 K.

DOI： 10.1246/cl.2010.918

Other Link： http://orcid.org/0000-0003-1774-1537

Preparation and characterization of active Ni/MgO in oxidative steam reforming of n-C(4)H(10) Reviewed

Katsutoshi Sato, Fumiaki Sago, Katsutoshi Nagaoka, Yusaku Takita

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Vol. 35 ( 11 ) page： 5393 - 5399 2010.6

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Oxidative steam reforming of n-C(4)H(10) over MgO-supported Ni catalysts is described. The Ni/MgO catalysts were prepared by the impregnation method from aqueous Ni(NO(3))(2) precursor solutions at two pH values. Ni/MgO prepared at pH 7 exhibited considerably higher activity than Ni/MgO prepared from a conventional acidic aqueous precursor solution (pH 3.5). The H(2) formation rate for the modified Ni/MgO was up to 2.3 times that for conventional Ni/MgO under a high space velocity of 1660 L(h g)(-1). Furthermore, after reduction at high temperature (1273 K), the modified Ni/MgO showed a higher H(2) formation rate than did Rh/MgO. The superior performance of the modified Ni/MgO was ascribed to stronger resistance to oxidation of Ni(o) due to the formation of relatively large Ni(o) particles. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ijhydene.2010.03.028

Other Link： http://orcid.org/0000-0003-1774-1537

Hydrogen Production from Bioethanol: Oxidative Steam Reforming of Aqueous Ethanol Triggered by Oxidation of Ni/Ce0.5Zr0.5O2-x at Low Temperature Reviewed

Katsutoshi Sato, Kosuke Kawano, Akiko Ito, Yusaku Takita, Katsutoshi Nagaoka

CHEMSUSCHEM Vol. 3 ( 12 ) page： 1364 - 1366 2010

Metal phosphate and fluoride catalysts active for hydrolysis of NF3 Reviewed

Takeshi Takubo, Yutaka Hirose, Daishin Kashiwagi, Takanori Inoue, Hisatoshi Yamada, Katsutoshi Nagaoka, Yusaku Takita

CATALYSIS COMMUNICATIONS Vol. 11 ( 3 ) page： 147 - 150 2009.11

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

NF3 was decomposed over various ortho, pyrophosphates and some fluorides at 450-600 K. Mn2P2O7 and CePO4 were the most active. The catalytic activity of Co2P2O7, Co-3(PO4)(2), CrPO4, Cu2P2O7, and Cr-4(P2O7)(3) followed in this order. Zn-3(PO4)(2) and AlPO4 were less active. Activity of pyrophosphate was comparable to that of ortho-phosphate. Products were NO2 and a very small amount of N2O except for HE An essential reaction was 2NF(3) + 3H(2)O -> 6HF + NO + NO2. Catalytic activity of phosphates was proportional to not the amount but the concentration of surface hydroxyls, suggesting that the reaction proceeds via a bidentate surface intermediate. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.catcom.2009.09.005

Other Link： http://orcid.org/0000-0003-1774-1537

Mechanism of Promotion Effects of Ce added to AlPO4 Effective for CFC Decomposition Reviewed

Takubo Takeshi, Sato Daigo, Inao Yasutaka, Nishiguchi Hiroyasu, Nagaoka Katsutoshi, Takita Yusaku

KAGAKU KOGAKU RONBUNSHU Vol. 35 ( 6 ) page： 623 - 632 2009.11

Catalytic behavior of Ni/ZrxTi1-xO2 and the effect of SiO2 doping in oxidative steam reforming of n-butane Reviewed

Fumiaki Sago, Sho Fukuda, Katsutoshi Sato, Katsutoshi Nagaoka, Hiroyasu Nishiguchi, Yusaku Takita

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY Vol. 34 ( 19 ) page： 8046 - 8052 2009.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Catalytic behaviors of TiO2-, Zr0.5Ti0.5O2-, and ZrO2-supported Ni catalysts were investigated for oxidative steam reforming of n-C4H10 at 723 K. The composite oxide support, Zr0.5Ti0.5O2, shows high specific surface area (136 m(2)/g), leading to fine Ni particles. Thus, the Ni/Zr0.5Ti0.5O2 catalyst exhibits higher and more stable activity than that exhibited by other catalysts. However, relatively large amounts of coke are deposited on the catalyst during reaction. Thus, to retard carbon deposition, the influence of SiO2 additive was studied. Large amounts of SiO2 additive (5 or 10 mol%) decrease initial activity; at 10 mol%, degradation is also induced by oxidation of Ni-o. However, small amounts of SiO2 additive (1.5 mol%) effectively retard coking without lowering initial activity. The resultant Ni/Zr0.5Ti0.5O2-SiO2 (1.5 mol%) catalyst exhibits high and stable activity without coking. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.ijhydene.2009.08.005

Other Link： http://orcid.org/0000-0003-1774-1537

Initiation of Oxidative Reforming of Butane over Praseodymium Oxide Supported Ni Catalysts at Ambient Temperature Reviewed Open Access

Sato Katsutoshi, Nagaoka Katsutoshi, Nishiguchi Hiroyasu, Takita Yusaku

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE Vol. 52 ( 5 ) page： 295 - 296 2009.9

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