研究者詳細 - 永岡　勝俊

Efficient metallic Ni as a bifunctional electrocatalyst for integrating continuous PET plastic upcycling with hydrogen production 査読有り国際共著

Li X., Sun J., Ma H., Long X., Li T., Shimoyama Y., Naito T., Sato K., Yamada H., Nagaoka K., Zhao Y., Qian X.

Applied Catalysis B: Environmental 371 巻 2025年8月

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Catalysis B: Environmental

Electrocatalytic upcycling of polyethylene terephthalate (PET) plastic wastes into value-added chemicals is promising to alleviate the environmental and energy crisis. However, the cost effectiveness and long-term stability are still facing great challenges for up-scaling applications. Herein, we developed an efficient and stable metallic Ni bifunctional electrocatalyst for the electrocatalytic upcycling of PET plastic wastes coupled with hydrogen production. The metallic Ni deposited on nickel foam exhibited a current density of 100 mA cm−2 at 1.4 VRHE, and an optimal Faradaic efficiency to formic acid (FEFA) of 90 % at 1.5 VRHE for the anodic ethylene glycol oxidation reaction (EGOR), while presenting an overpotential of 250 mV at 100 mA cm−2 and Faradaic efficiency to hydrogen (FEH2) close to 100 % for the cathodic hydrogen evolution reaction (HER). Mechanistic studies demonstrated the structural reconstruction of metallic Ni into amorphous nickel (oxy)hydroxides as the reactive sites for the EGOR process. A flow cell reactor was assembled by utilizing the bifunctional electrocatalyst as both anode and cathode. A long-term stability was achieved at a constant current density of 100 mA cm−2 for 720 h. The superior catalytic performance, long-term stability and economic efficiency of the bifunctional metallic Ni electrocatalyst provide great potential for future scaling up.

DOI： 10.1016/j.apcatb.2025.125211

Atomic behaviors in PdRu solid-solution nanoparticles on CeO2-ZrO2 support for the three-way catalytic reaction 査読有り Open Access

Seo O., Tayal A., Kim J., Kusada K., Yamamoto T., Tang J., Hiroi S., Song C., Sato K., Nagaoka K., Haneda M., Kato K., Matsumura S., Kitagawa H., Sakata O.

Materials Today Catalysis 7 巻頁： 100078 - 100078 2024年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Materials Today Catalysis

Understanding the behavior of noble-metal catalysts is a key point of catalysis research aimed at reducing the environmental and economic costs associated with the increased use of automobiles. In this study, the atomic-behaviors of Ru and Pd atoms in PdRu solid-solution nanoparticles (NPs) supported on CeO2-ZrO2 (CZ) as a Rh-free three-way catalyst in a modeled three-way catalytic reaction (TWCR) were elucidated using a gas conversion analysis, transmission electron microscopy, and in-situ X-ray absorption fine structure spectroscopy. We found that the PdRu NPs enlarged by the annealing effect separated a smaller grain size with the Pd-rich and Ru-rich phase under TWCR. Most of the oxidation and reduction reactions under the modeled TWCR occurred on the Ru. However, the Pd metals acted as a major role of the reduction of NO gas and oxidation of CO and C3H6 gas. Ru atoms just is a minor role during the modeled TWCR. This study demonstrates the potential of PdRu NPs as a three-way catalyst and reveals the atomic-behavior and catalytic role under the modeled TWCR.

DOI： 10.1016/j.mtcata.2024.100078

Open Access

Significant low-temperature activity of tetragonal type ZrO2-supported Ru catalysts for CO2 methanation 査読有り

Sato, K; Higuchi, H; Nagaoka, K

CHEMISTRY LETTERS 53 巻 ( 10 ) 2024年10月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry Letters

Conversion of CO2 with H2 to CH4 is a potential route for the utilization of CO2. Because CO2 methanation is an exothermic reaction, the equilibrium yield decreases with increasing temperature. A catalyst that exhibits high activity at low temperatures is thus highly desirable. We report here that a tetragonal-type ZrO2-supported Ru catalyst prepared by low-temperature calcination showed significant low-temperature activity for CO2 methanation. We surmise that an intermediate formate species formed over the tetragonal-type ZrO2 and enhanced the catalytic activity.

DOI： 10.1093/chemle/upae178

Rapid start-up of carbon-free H2 production by ammonia oxidative decomposition over Co/Ce0.5 Zr0.5 O2 with microwave irradiation 査読有り Open Access

Matsunaga, T; Hayashi, S; Yamada, H; Sato, K; Nagaoka, K

ISCIENCE 27 巻 ( 8 ) 頁： 110452 - 110452 2024年8月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：iScience

Hydrogen is a promising combustion improver for use with ammonia fuels, but a cost-effective method for easily producing hydrogen from ammonia at a high rate has yet to be developed. Here, we show that microwave irradiation instantly triggers oxidative decomposition of ammonia over a Co/Ce0.5Zr0.5O2 catalyst to produce hydrogen at a high rate. The microwave irradiation rapidly heats the inside of the catalyst from room temperature to the catalytic auto-ignition temperature of ammonia, thus initiating exothermic oxidative decomposition of ammonia to produce hydrogen. This method provides a highly efficient means of producing hydrogen for potential use in a carbon-free, ammonia-fueled power generation process.

DOI： 10.1016/j.isci.2024.110452

Barium-doped iron nanoparticles supported on MgO as an efficient catalyst for ammonia synthesis under mild reaction conditions 査読有り Open Access

Era K., Sato K., Miyahara S.I., Naito T., De Silva K., Akrami S., Yamada H., Toriyama T., Tamaoka T., Yamamoto T., Murakami Y., Inazu K., Nagaoka K.

Sustainable Energy and Fuels 8 巻 ( 12 ) 頁： 2593 - 2600 2024年5月

担当区分：最終著者,　責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Sustainable Energy and Fuels

To realize a carbon-neutral society, developing highly active and inexpensive catalysts for ammonia (NH3) production working under moderate conditions (<400 °C, <10 MPa) using hydrogen fabricated from the electrolysis of water is demanded. Current industrial fused iron (Fe) catalysts show deficient activity under such conditions. Although Ru-based catalysts have been introduced as highly efficient catalysts working under desired conditions, they are scarce and consequently expensive. This work introduces Fe/Ba/MgO (reduced at 700 °C) as an active catalyst with a high ammonia production rate working at mild temperature and pressure (350 °C, 1.0 MPa). Ba doping to Fe nanoparticles supported on MgO and pre-reduction at high temperatures dramatically ameliorated the NH3 production rate. Due to the absence of hydrogen poisoning, the catalytic activity of the Fe/Ba/MgO increased gradually by raising the pressure from 0.1 to 3.0 MPa. The activity of this catalyst at 3.0 MPa was higher than that of two benchmark Ru catalysts. After pre-reduction at high temperature, electrons are donated from the BaO encapsulating the Fe0 nanoparticles to the N2 molecule, which promotes the rate-determining step of ammonia synthesis. We anticipate that these findings will contribute to developing inexpensive Fe catalysts for decarbonizing the ammonia synthesis process to achieve a carbon-neutral society.

DOI： 10.1039/d4se00411f

Open Access

Effects of the Topological Structure of Different Cu-Zeolites on the Relationship between Soot and NOx Removal on NH3–SCRF 査読有り

Zhimu Ye, Pengcheng Zhao, Xincheng Tang, Takeshi Hagio, Katsutoshi Sato, Katsutoshi Nagaoka, Xinling Li

Energy & Fuels 38 巻頁： 2212 - 2223 2024年1月

Catalytic Behavior of K-doped Fe/MgO Catalysts for Ammonia Synthesis Under Mild Reaction Conditions 査読有り Open Access

Era K., Sato K., Miyahara S.i., Naito T., De Silva K., Akrami S., Yamada H., Toriyama T., Yamamoto T., Murakami Y., Aika K.i., Inazu K., Nagaoka K.

ChemSusChem 16 巻 ( 22 ) 頁： e202300942 2023年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ChemSusChem

An important part of realizing a carbon-neutral society using ammonia will be the development of an inexpensive yet efficient catalyst for ammonia synthesis under mild reaction conditions (<400 °C, <10 MPa). Here, we report Fe/K(3)/MgO, fabricated via an impregnation method, as a highly active catalyst for ammonia synthesis under mild reaction conditions (350 °C, 1.0 MPa). At the mentioned conditions, the activity of Fe/K(3)/MgO (17.5 mmol h−1 gcat−1) was greater than that of a commercial fused iron catalyst (8.6 mmol h−1 gcat−1) currently used in the Haber-Bosch process. K doping was found to increase the ratio of Fe0 on the surface and turnover frequency of Fe in our Fe/K(3)/MgO catalyst. In addition, increasing the pressure to 3.0 MPa at the same temperature led to a significant improvement of the ammonia synthesis rate to 29.6 mmol h−1 gcat−1, which was higher than that of two more expensive, benchmark Ru-based catalysts, which are also potential alternative catalysts. A kinetics analysis revealed that the addition of K enhanced the ammonia synthesis activity at ≥300 °C by changing the main adsorbed species from NH to N which can accelerate dissociative adsorption of nitrogen as the rate limiting step in ammonia synthesis.

DOI： 10.1002/cssc.202300942

The Effect of Ru Precursor and Support on the Hydrogenation of Aromatic Aldehydes/Ketones to Alcohols 査読有り Open Access

Chaudhari, C; Sato, K; Miyahara, S; Yamamoto, T; Toriyama, T; Matsumura, S; Kusuda, K; Kitagawa, H; Nagaoka, K

CHEMCATCHEM 14 巻 ( 16 ) 2022年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ChemCatChem

Supported Ru catalysts were prepared by using different Ru precursors and examined for the hydrogenation of benzaldehyde to CHM. The catalyst prepared from Ru3(CO)12 precursor and HT support exhibited high yield of CHM. Moderate acidic and basic nature of HT was favourable to control the selectivity for CHM. The physicochemical properties analysis revealed that highly dispersed Ru nanoparticles were effective for the hydrogenation of benzaldehyde. RuCO/HT catalyst was tolerant to different functional groups and was stable until 7th cycle of recycle study.

DOI： 10.1002/cctc.202200241

Co Nanoparticle Catalysts Encapsulated by BaO-La2O3 Nanofractions for Efficient Ammonia Synthesis Under Mild Reaction Conditions 査読有り Open Access

Miyahara, SI; Sato, K; Tsujimaru, K; Wada, Y; Ogura, Y; Toriyama, T; Yamamoto, T; Matsumura, S; Inazu, K; Nagaoka, K

ACS OMEGA 7 巻 ( 28 ) 頁： 24452 - 24460 2022年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Omega

Ruthenium catalysts may allow for realization of renewable energy-based ammonia synthesis processes using mild reaction conditions (<400 °C, <10 MPa). However, ruthenium is relatively rare and therefore expensive. Here, we report a Co nanoparticle catalyst loaded on a basic Ba/La2O3support and prereduced at 700 °C (Co/Ba/La2O3_700red) that showed higher ammonia synthesis activity at 350 °C and 1.0-3.0 MPa than two benchmark Ru catalysts, Cs+/Ru/MgO and Ru/CeO2. The synthesis rate of the catalyst at 350 °C and 1.0 MPa (19.3 mmol h-1g-1) was 8.0 times that of Co/Ba/La2O3_500red and 6.9 times that of Co/La2O3_700red. The catalyst showed ammonia synthesis activity at temperatures down to 200 °C. Reduction at the high temperature induced the formation of BaO-La2O3nanofractions around the Co nanoparticles by decomposition of BaCO3, which increased turnover frequency, inhibited the sintering of Co nanoparticles, and suppressed ammonia poisoning. These strategies may also be applicable to other non-noble metal catalysts, such as nickel.

DOI： 10.1021/acsomega.2c01973

Operando Spectroscopic Study of the Dynamics of Ru Catalyst during Preferential Oxidation of CO and the Prevention of Ammonia Poisoning by Pt 査読有り Open Access

Sato, K; Zaitsu, S; Kitayama, G; Yagi, S; Kayada, Y; Nishida, Y; Wada, Y; Nagaoka, K

JACS AU 2 巻 ( 7 ) 頁： 1627 - 1637 2022年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：JACS Au

Hydrogen is a promising clean energy source. In domestic polymer electrolyte fuel cell systems, hydrogen is produced by reforming of natural gas; however, the reformate contains carbon monoxide (CO) as a major impurity. This CO is removed from the reformate by a combination of the water-gas shift reaction and preferential oxidation of CO (PROX). Currently, Ru-based catalysts are the most common type of PROX catalyst; however, their durability against ammonia (NH3) as an impurity produced in situ from trace amounts of nitrogen also contained in the reformate is an important issue. Previously, we found that addition of Pt to an Ru catalyst inhibited deactivation by NH3. Here, we conducted operando XAFS and FT-IR spectroscopic analyses with simultaneous gas analysis to investigate the cause of the deactivation of an Ru-based PROX catalyst (Ru/α-Al2O3) by NH3and the mechanism of suppression of the deactivation by adding Pt (Pt/Ru/α-Al2O3). We found that nitric oxide (NO) produced by oxidation of NH3induces oxidation of the Ru nanoparticle surface, which deactivates the catalyst via a three-step process: First, NO directly adsorbs on Ru0to form NO-Ruδ+, which then induces the formation of O-Run+by oxidation of the surrounding Ru0. Then, O-Rum+is formed by oxidation of Ru0starting from the O-Run+nuclei and spreading across the surface of the nanoparticle. Pt inhibits this process by alloying with Ru and inducing the decomposition of adsorbed NO, which keeps the Ru in a metallic state.

DOI： 10.1021/jacsau.2c00195

Direct high-purity hydrogen production from ammonia by using a membrane reactor combining V-10mol%Fe hydrogen permeable alloy membrane with Ru/Cs<inf>2</inf>O/Pr<inf>6</inf>O<inf>11</inf> ammonia decomposition catalyst 査読有り Open Access

Omata K., Sato K., Nagaoka K., Yukawa H., Matsumoto Y., Nambu T.

International Journal of Hydrogen Energy 47 巻 ( 13 ) 頁： 8372 - 8381 2022年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Hydrogen Energy

The hydrogen production capabilities of the membrane reactor combining V-10 mol%Fe hydrogen permeable alloy membrane with Ru/Cs2O/Pr6O11 ammonia decomposition catalyst are studied. The ammonia conversion is improved by 1.7 times compared to the Ru/Cs2O/Pr6O11 catalyst alone by removing the produced hydrogen through the V-10mol%Fe alloy membrane during the ammonia decomposition. 79% of the hydrogen atoms contained in the ammonia gas are extracted directly as high-purity hydrogen gas. Both the Ru/Cs2O/Pr6O11 catalyst and the V-10 mol% Fe alloy membrane are highly durable, and the initial performance of the hydrogen separation rate lasts for more than 3000 h. The produced hydrogen gas conforms to ISO 14687–2:2019 Grade D for fuel cell vehicles because the ammonia and nitrogen concentrations are less than 0.1 ppm and 100 ppm, respectively.

DOI： 10.1016/j.ijhydene.2021.12.191

Rh-PVP Catalyzed Reductive Amination of Phenols by Ammonia or Amines to Cyclohexylamines under Solvent-free Conditions 査読有り Open Access

Chaudhari C., Sato K., Rumi S., Nishida Y., Shiraishi M., Nagaoka K.

Chemistry Letters 51 巻 ( 1 ) 頁： 81 - 84 2022年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry Letters

Colloidal metal nanoparticles were examined for reductive amination of phenol by ammonia under mild reaction conditions. The results showed that Rh-PVP was the most active catalyst for reductive amination reaction. Linear, cyclic, and amino alcohols were used as nucleophiles and converted to primary/secondary/tertiary amines. Using this strategy, the synthesis of an industrially important chemical, N-cyclohexyl- 2-pyrrolidone was explored.

DOI： 10.1246/cl.210574

Nitrile hydrogenation to secondary amines under ambient conditions over palladium-platinum random alloy nanoparticles 査読有り Open Access

Nishida Y., Sato K., Chaudhari C., Yamada H., Toriyama T., Yamamoto T., Matsumura S., Aspera S.M., Nakanishi H., Haneda M., Nagaoka K.

Catalysis Science and Technology 12 巻 ( 13 ) 頁： 4128 - 4137 2022年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Catalysis Science and Technology

Catalytic hydrogenation of nitriles is a cost-effective and green method for synthesizing amines and imines, which have many industrial applications. However, this reaction generally requires harsh reaction conditions and produces a mixture of amine and imine products due to its chemodiversity. Therefore, it is a challenge to selectively hydrogenate nitriles to a single product under ambient conditions (1 bar of H2 at 25 °C). Here, we report an effective method for selective hydrogenation of nitriles that does not require heat, pressurization, or long reaction times. We achieved this by means of bimetalization between palladium (Pd) and platinum (Pt) nanoparticles, which resulted in a catalyst that showed high yield of secondary amines. Although Pd and Pt are thermodynamically immiscible, we have successfully alloyed the two metals by means of rapid chemical reduction assisted by microwave heating. X-ray absorption spectroscopy suggested the formation of heteroatomic Pdδ+Ptδ− sites via charge transfer between neighboring Pd and Pt atoms in the alloy structure. Moreover, Fourier transform IR spectroscopy and scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy indicated that decreasing the size of the PdPt (50 : 50) nanoparticles improved the degree of alloying and facilitated the formation of electron-enriched Ptδ− species. On the basis of kinetics studies and density functional theory calculations, we concluded that cyano group activation, which was the rate-determining step over monometallic Pd and Pt catalysts, was accelerated over the heteroatomic Pdδ+Ptδ− sites because of strong back-donation from electron-enriched Ptδ− species to the carbon atom of the cyano groups. The PdPt random alloy nanoparticles catalyzed the reactions of various aromatic and heterocyclic nitriles, and the corresponding secondary amines were selectively obtained in just a few hours.

DOI： 10.1039/d1cy02302k

Open Access

Co/Ba/La2O3 catalyst for ammonia synthesis under mild reaction conditions 査読有り

Katsutoshi Nagaoka, Shin-ichiro Miyahara, Katsutoshi Sato, Yuta Ogura, Kotoko Tsujimaru, Yuichiro Wada, Takaaki Toriyama, Tomokazu Yamamoto, Syo Matsumura, Koji Inazu

2021年12月

Barium oxide encapsulating cobalt nanoparticles supported on magnesium oxide: Active non-noble metal catalysts for ammonia synthesis under mild reaction conditions 査読有り Open Access

Sato K., Nagaoka K., Miyahara S.I., Tsujimaru K., Wada Y., Toriyama T., Yamamoto T., Matsumura S., Inazu K., Mohri H., Iwasa T., Taketsugu T.

ACS Catalysis 11 巻 ( 21 ) 頁： 13050 - 13061 2021年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Catalysis

To realize a carbon-free society, catalysts are needed for the synthesis of ammonia under mild reaction conditions (<400 °C, <10 MPa) that use hydrogen produced from renewable energy. Ru-based catalysts are currently the most promising candidates; however, Ru is expensive and of low abundance. Here, we discovered that the encapsulation of Co nanoparticles with BaO enhanced the ammonia synthesis activity of Co and that a simple Ba-doped Co/MgO catalyst prereduced at an unusually high temperature of 700 °C (Co@BaO/MgO-700red) showed outstanding ammonia synthesis activity. The ammonia synthesis rate (24.6 mmol gcat−1 h−1) and turnover frequency (0.246 s−1) of the catalyst at 350 °C and 1.0 MPa were about 80 and 250 times higher, respectively, than those of the nondoped parent catalyst. At the same temperature but higher pressure (3.0 MPa), the ammonia synthesis rate was increased to 48.4 mmol gcat−1 h−1, which is higher than that of active Ru-based catalysts. In addition, at 1.0 MPa, our catalyst produced ammonia even at temperatures as low as 150 °C. Scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy investigations revealed that after reduction at 700 °C, the Co nanoparticles had become encapsulated by a nanofraction of BaO. The mechanism underlying the formation of this unique structure was considered to comprise reduction of oxidic Co to metallic Co, decomposition of BaCO3 to BaO, and migration of BaO and Co nanoparticles. Spectroscopic and density functional theory investigations revealed that adsorption of N2 on the Co atoms at the catalyst surface weakened the N2 triple bond to the strength of a double bond due to electron donation from Ba2+ of BaO via adjacent Co atoms; this weakening accelerated the cleavage of the triple bond, which is the rate-determining step for ammonia synthesis.

DOI： 10.1021/acscatal.1c02887

Ammonia synthesis over lanthanoid oxide–supported ruthenium catalysts 査読有り Open Access

Miyahara S.i., Sato K., Kawano Y., Imamura K., Ogura Y., Tsujimaru K., Nagaoka K.

Catalysis Today 376 巻頁： 36 - 40 2021年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Catalysis Today

Ammonia synthesis catalysts with high activity under mild reaction conditions for use in synthetic chemical processes powered by renewable energy are needed. Here, we investigated the physicochemical properties and ammonia synthesis activity of lanthanoid oxide–supported Ru catalysts. The basicity of the Ru/lanthanoid oxide catalysts, as estimated by CO2 temperature-programmed desorption, was higher than that of Ru/MgO, a representative catalyst with high ammonia synthesis activity, and a positive relationship was observed between basicity and turnover frequency. The turnover frequency of Ru/Pr2O3 and Ru/La2O3 (both 0.24 s−1) was eight times that of Ru/MgO (0.03 s−1). A kinetic analysis revealed that hydrogen poisoning, which is a typical drawback of oxide-supported Ru catalysts, was markedly retarded in the Ru/lanthanoid oxide catalysts. As a result, the ammonia synthesis rate of the Ru/Pr2O3 catalyst increased with increasing reaction pressure, reaching 49 mmol g−1 h−1 at 400 °C and 1.0 MPa, which was 12 times that of Ru/MgO under the same conditions.

DOI： 10.1016/j.cattod.2020.08.031

One-pot synthesis of cyclohexylamine and N-aryl pyrroles via hydrogenation of nitroarenes over the Pd0.5Ru0.5-PVP catalyst 査読有り

Chaudhari, C; Sato, K; Ikeda, Y; Terada, K; Abe, N; Nagaoka, K

NEW JOURNAL OF CHEMISTRY 45 巻 ( 22 ) 頁： 9743 - 9746 2021年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：New Journal of Chemistry

The direct synthesis of cyclohexylamine via the hydrogenation of nitrobenzene over monometallic (Pd, Ru or Rh) and bimetallic (PdxRu1-x) catalysts was studied. The Pd0.5Ru0.5-PVP catalyst was the most effective catalyst for this reaction. The catalyst can be reused and applied for the synthesis of N-aryl pyrroles and quinoxalines from nitrobenzenes.

DOI： 10.1039/d1nj00922b

Highly Stable and Active Solid-Solution-Alloy Three-Way Catalyst by Utilizing Configurational-Entropy Effect 査読有り

Kusada K., Wu D., Nanba Y., Koyama M., Yamamoto T., Tran X.Q., Toriyama T., Matsumura S., Ito A., Sato K., Nagaoka K., Seo O., Song C., Chen Y., Palina N., Kumara L.S.R., Hiroi S., Sakata O., Kawaguchi S., Kubota Y., Kitagawa H.

Advanced Materials 33 巻 ( 16 ) 頁： e2005206 2021年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Advanced Materials

Since 1970, people have been making every endeavor to reduce toxic emissions from automobiles. After the development of a three-way catalyst (TWC) that concurrently converts three harmful gases, carbon monoxide (CO), hydrocarbons (HCs), and nitrogen oxides (NOx), Rh became an essential element in automobile technology because only Rh works efficiently for catalytic NOx reduction. However, due to the sharp price spike in 2007, numerous efforts have been made to replace Rh in TWCs. Nevertheless, Rh remains irreplaceable, and now, the price of Rh is increasing significantly again. Here, it is demonstrated that PdRuM ternary solid-solution alloy nanoparticles (NPs) exhibit highly durable and active TWC performance, which will result in a significant reduction in catalyst cost compared to Rh. This work provides insights into the design of highly durable and efficient functional alloy NPs, guiding how to best take advantage of the configurational entropy in addition to the mixing enthalpy.

DOI： 10.1002/adma.202005206

PubMed

Boosting Ammonia Synthesis under Mild Reaction Conditions by Precise Control of the Basic Oxide–Ru Interface

Sato Katsutoshi, Nagaoka Katsutoshi

Chemistry Letters 50 巻 ( 4 ) 頁： 687 - 696 2021年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：公益社団法人日本化学会

Strong basic oxide–supported Ru catalysts are easily prepared and handled, and they have been used as effective catalysts for ammonia synthesis under mild reaction conditions since the 1970s. Recent research has revealed that precise control of the boundary states between the basic oxide (i.e., rare-earth oxide, alkali earth oxide), oxygen defect sites, and Ru nanoparticles can be used to enhance ammonia synthesis under mild reaction conditions and inhibit hydrogen poisoning, which is a typical drawback of strong basic oxide–supported Ru catalysts.

DOI： 10.1246/CL.200855

DOI： 10.1246/cl.200855

Nonequilibrium Flow-Synthesis of Solid-Solution Alloy Nanoparticles: From Immiscible Binary to High-Entropy Alloys 査読有り

Kusada, K; Yamamoto, T; Toriyama, T; Matsumura, S; Sato, K; Nagaoka, K; Terada, K; Ikeda, Y; Hirai, Y; Kitagawa, H

JOURNAL OF PHYSICAL CHEMISTRY C 125 巻 ( 1 ) 頁： 458 - 463 2021年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Physical Chemistry C

Solid-solution alloy nanoparticles (NPs), where the constituents mix at the atomic level, show a variety of attractive properties due to their tunable electronic structures. However, it is still difficult to stably synthesize them, particularly nonequilibrium alloys that consist of combinations immiscible in the bulk. Here, we first report the successful syntheses of solid-solution alloy NPs including PdRu and PdRuIr, which are immiscible in the bulk, and of IrPdPtRhRu high-entropy alloy NPs through a continuous-flow reactor providing a high productivity with high reproducibility. The designed solvothermal flow reactor enabled us to use a lower alcohol as a reductant that cannot be applied in a batch synthesis for these NPs.

DOI： 10.1021/acs.jpcc.0c08871

Chemoselective hydrogenation of heteroarenes and arenes by Pd-Ru-PVP under mild conditions 査読有り Open Access

Chaudhari, C; Sato, K; Nishida, Y; Yamamoto, T; Toriyama, T; Matsumura, S; Ikeda, Y; Terada, K; Abe, N; Kusuda, K; Kitagawa, H; Nagaoka, K

RSC ADVANCES 10 巻 ( 72 ) 頁： 44191 - 44195 2020年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：RSC Advances

Monometallic (Pd, Ru or Rh) and bimetallic (Pd0.5-Ru0.5) alloy NPs catalysts were examined for the hydrogenation of quinoline. Pd-Ru alloy catalyst showed superior catalytic activity to the traditional Rh catalyst. The characterization of Pd0.5-Ru0.5 catalysts, HAADF-EDX mapping and XPS analysis suggested that the alloy state of PdRu catalysts remained unchanged in the recovered catalyst. Furthermore, the catalyst was highly selective for the hydrogenation of different arenes. This journal is

DOI： 10.1039/d0ra09981c

One-pot synthesis of pyrrolidones from levulinic acid and amines/nitroarenes/nitriles over the Ir-PVP catalyst 査読有り

Chaudhari, C; Shiraishi, M; Nishida, Y; Sato, K; Nagaoka, K

GREEN CHEMISTRY 22 巻 ( 22 ) 頁： 7760 - 7764 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Green Chemistry

The synthesis of pyrrolidones via reductive amination of levulinic acid with aniline was examined over polypyrrolidone-stabilized metal nanoparticle catalysts. Among them, Ir metal was the most effective and applicable for the reductive amination of levulinic acid with nitroarenes/nitriles. Importantly, this catalyst was used for the one-pot synthesis of the anti-inflammatory drug indoprofen from 2-formylbenzoic acid and 2-(4-nitrophenyl)propanoic acid.

DOI： 10.1039/d0gc01725f

Oxidation of Ru/Ce0.5Zr0.5O2-x at Ambient Temperature as a Trigger for Carbon-Free H2 Production by Ammonia Oxidative Decomposition 査読有り

Coreduction methodology for immiscible alloys of CuRu solid-solution nanoparticles with high thermal stability and versatile exhaust purification ability 査読有り Open Access

Huang, B; Kobayashi, H; Yamamoto, T; Matsumura, S; Nishida, Y; Sato, K; Nagaoka, K; Haneda, M; Kawaguchi, S; Kubotak, Y; Kitagawa, H

CHEMICAL SCIENCE 11 巻 ( 42 ) 頁： 11413 - 11418 2020年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Science

This study provides a coreduction methodology for solid solution formation in immiscible systems, with an example of a whole-region immiscible Cu-Ru system. Although the binary Cu-Ru alloy system is very unstable in the bulk state, the atomic-level well-mixed CuRu solid solution nanoparticles were found to have high thermal stability up to at least 773 K in a vacuum. The exhaust purification activity of the CuRu solid solution was comparable to that of face-centred cubic Ru nanoparticles. According to in situ infrared measurements, stronger NO adsorption and higher intrinsic reactivity of the Ru site on the CuRu surface than that of a pure Ru surface were found, affected by atomic-level Cu substitution. Furthermore, CuRu solid solution was a versatile catalyst for purification of all exhaust gases at a stoichiometric oxygen concentration. This journal is

DOI： 10.1039/d0sc03373a

Matsunaga, T; Matsumoto, S; Tasaki, R; Ogura, Y; Eboshi, T; Takeishi, Y; Honda, K; Sato, K; Nagaoka, K

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 8 巻 ( 35 ) 頁： 13369 - 13376 2020年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Sustainable Chemistry and Engineering

Ammonia has received attention as a hydrogen carrier for energy use, and although ammonia decomposition can produce hydrogen at a high rate, there is currently no simple process for decomposing ammonia that is easily and rapidly initiated at any time without an input of external energy. Here, we report the discovery of a process for initiating and sustaining the production of hydrogen from ammonia without heating the catalyst externally. The oxidative decomposition of ammonia to produce hydrogen at a high rate was repeatedly triggered at ambient temperature (∼25 °C) immediately after NH3 and O2 were supplied to a Ru/Ce0.5Zr0.5O2 catalyst that had been previously reduced at ambient temperature. For this catalyst, active hydrogen atoms formed on Ru0 nanoparticles reduced Ce0.5Zr0.5O2 even at ambient temperature, and the very exothermic oxidation of Ce0.5Zr0.5O2-x as well as Ru0 heated the catalyst bed to the catalytic auto-ignition temperature for ammonia combustion, which was lowered by the contribution of mobile (active) oxygen over the Ce0.5Zr0.5O2. Oxidative ammonia decomposition was thereby triggered.

DOI： 10.1021/acssuschemeng.0c04126

Effect of Calcination and Reduction Temperatures on the Catalytic Activity of Ru/La0.5Ce0.5O1.75 for Ammonia Synthesis under Mild Conditions 査読有り Open Access

Ogura, Y; Asai, T; Sato, K; Miyahara, S; Toriyama, T; Yamamoto, T; Matsumura, S; Nagaoka, K

ENERGY TECHNOLOGY 8 巻 ( 6 ) 頁： 2000264 2020年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy Technology

Ammonia is a potential carrier of hydrogen as a zero-emission fuel. Herein, the effects of calcination and reduction temperatures on the ammonia-synthesis activity of Ru/La0.5Ce0.5O1.75 are investigated under mild synthesis conditions (≤400 °C, ≤3 MPa), which are the preferred conditions for the storage of hydrogen as an energy source. The highest catalytic activity is obtained after calcination of the support at 700 °C and reduction of the catalyst at 650 °C. Calcination using a higher temperature than that used for reduction results in the induction of a strong metal–support interaction (SMSI) effect. This high-temperature calcination also provides heat resistance to the support, which prevents sintering of the primary support particles during reduction. Thus, calcination and reduction at temperatures higher than those normally used for the preparation of Ru catalysts provide a novel approach for obtaining supported highly dispersed Ru catalysts exhibiting the SMSI effect and high catalytic activities.

DOI： 10.1002/ente.202000264

Surface Dynamics for Creating Highly Active Ru Sites for Ammonia Synthesis: Accumulation of a Low-Crystalline, Oxygen-Deficient Nanofraction 査読有り

Pr2O3 Supported Nano-layered Ruthenium Catalyzed Acceptorless Dehydrogenative Synthesis of 2-Substituted Quinolines and 1,8-Naphthyridines from 2-Aminoaryl Alcohols and Ketones 査読有り Open Access

Chaudhari, C; Sato, K; Ogura, Y; Miayahara, SI; Nagaoka, K

CHEMCATCHEM 12 巻 ( 8 ) 頁： 2198 - 2202 2020年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ChemCatChem

Pr2O3 supported Ru nanolayers and Ru nanoparticles catalysts were examined for the synthesis of quinolines. The Ru nanolayer was most active catalyst and showed a broad substrate scope. Structure-activity relationship demonstrated that the metallic state and morphology of Ru as well as the basic site of Pr2O3 were indispensable factors of this catalytic system.

DOI： 10.1002/cctc.201902311

Sato, K; Miyahara, SI; Ogura, Y; Tsujimaru, K; Wada, Y; Toriyama, T; Yamamoto, T; Matsumura, S; Nagaoka, K

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 8 巻 ( 7 ) 頁： 2726 - 2734 2020年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Sustainable Chemistry and Engineering

To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity per weight of catalyst of Ru/Ba/LaCeOx, prereduced at 700 °C, is the highest among reported oxide-supported Ru catalysts, 52.3 mmol h-1 gcat-1 at 350 °C, 1.0 MPa. The turnover frequency of Ru/Ba/LaCeOx at 350 °C was more than 8 times that of Cs+/Ru/MgO, which is a well-known active catalyst used as a benchmark; furthermore, hydrogen poisoning, a typical drawback for oxide-supported Ru catalysts, was effectively suppressed. Scanning transmission electron microscopy observations with energy dispersive X-ray spectrometry and electron energy loss spectroscopy analysis revealed that a low-crystalline, oxygen-deficient nanofraction including Ba2+, Ce3+, and La3+ had accumulated on the Ru particles. This unique structure was obtained by exploiting the surface dynamics of alkaline earth compounds and thermostable rare earth oxides that contain redox-active atoms during the reduction at an unusually high temperature. The nanofraction showed strong electron-donating ability because of the strong basicity of the included cations, removal of carbonate, and formation of oxygen defect sites that eliminated electron-withdrawing O2- anions from the interface between the nanofraction and Ru atom. Electrons were therefore effectively donated to antibonding π -orbitals of the N2 molecules via Ru in contact with the nanofraction, and NN triple bond cleavage, which is the rate-determining step for ammonia synthesis, was promoted.

DOI： 10.1021/acssuschemeng.9b06299

Kinetics of ammonia synthesis over Ru/Pr2O3 査読有り

Imamura, K; Miyahara, S; Kawano, Y; Sato, K; Nakasaka, Y; Nagaoka, K

JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS 105 巻頁： 50 - 56 2019年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

We investigated the kinetics of NH3 synthesis over a catalyst consisting of low-crystalline Ru nano-layers supported on Pr2O3. We determined the reaction orders with respect to N2, H2, and NH3 at various temperatures and pressures over Ru/Pr2O3, as well as Ru/CeO2 and Ru/MgO. The reaction orders with respect to N2 were always almost unity for all the catalysts under all the reaction conditions, indicating that the rate-determining step was NN bond cleavage. In contrast, the reaction orders with respect to H2 differed among the catalysts and decreased with increasing pressure and increased with increasing temperature. Under all conditions, the reaction order with respect to H2 was largest over Ru/Pr2O3 and smallest over Ru/MgO, indicating that hydrogen poisoning of the Ru surface was retarded to a greater extent over Ru/Pr2O3 than over Ru/MgO. In agreement with the trends of the H2 reaction orders, the NH3 synthesis rates over Ru/Pr2O3 at 400 °C rose drastically (64 mmol h−1 g−1) as the pressure was increased from 0.1 to 3.0 MPa. Furthermore, decreasing the feed gas H2/N2 ratio at 3.0 MPa effectively increased the NH3 synthesis rate over Ru/Pr2O3, which reached 45 mmol h−1 g−1 at 350 °C at a H2/N2 ratio of 1/0.5.

DOI： 10.1016/j.jtice.2019.10.006

Recyclable Rh-PVP nanoparticles catalyzed hydrogenation of benzoic acid derivatives and quinolines under solvent-free conditions 査読有り

Chaudhari, C; Imatome, H; Nishida, Y; Sato, K; Nagaoka, K

CATALYSIS COMMUNICATIONS 126 巻頁： 55 - 60 2019年6月

Pt-Co Alloy Nanoparticles on a γ-Al2O3 Support: Synergistic Effect between Isolated Electron-Rich Pt and Co for Automotive Exhaust Purification 査読有り

Sato, K; Ito, A; Tomonaga, H; Kanematsu, H; Wada, Y; Asakura, H; Hosokawa, S; Tanaka, T; Toriyama, T; Yamamoto, T; Matsumura, S; Nagaoka, K

CHEMPLUSCHEM 84 巻 ( 5 ) 頁： 447 - 456 2019年5月

Rh/Ce0.25Zr0.75O2 Catalyst for Steam Reforming of Propane at Low Temperature 査読有り

Yu, L; Sato, K; Nagaoka, K

CHEMCATCHEM 11 巻 ( 5 ) 頁： 1472 - 1479 2019年3月

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions 査読有り

Katsutoshi Sato, Shin-ichiro Miyahara, Yuta Ogura, Kotoko Tsujimaru, Yuichiro Wada, Takaaki Toriyama, Tomokazu Yamamoto, Syo Matsumura, Katsutoshi Nagaoka

2019年2月

A CO Adsorption Site Change Induced by Copper Substitution in a Ruthenium Catalyst for Enhanced CO Oxidation Activity 査読有り国際誌

Huang, B; Kobayashi, H; Yamamoto, T; Toriyama, T; Matsumura, S; Nishida, Y; Sato, K; Nagaoka, K; Haneda, M; Xie, W; Nanba, Y; Koyama, M; Wang, FL; Kawaguchi, S; Kubota, Y; Kitagawa, H

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 58 巻 ( 8 ) 頁： 2230 - 2235 2019年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Angewandte Chemie - International Edition

Ru is an important catalyst in many types of reactions. Specifically, Ru is well known as the best monometallic catalyst for oxidation of carbon monoxide (CO) and has been practically used in residential fuel cell systems. However, Ru is a minor metal, and the supply risk often causes violent fluctuations in the price of Ru. Performance-improved and cost-reduced solid-solution alloy nanoparticles of the Cu-Ru system for CO oxidation are now presented. Over the whole composition range, all of the Cu x Ru 1−x nanoparticles exhibit significantly enhanced CO oxidation activities, even at 70 at % of inexpensive Cu, compared to Ru nanoparticles. Only 5 at % replacement of Ru with Cu provided much better CO oxidation activity, and the maximum activity was achieved by 20 at % replacement of Ru by Cu. The origin of the high catalytic performance was found as CO site change by Cu substitution, which was investigated using in situ Fourier transform infrared spectra and theoretical calculations.

DOI： 10.1002/anie.201812325

Preparation of Noble-metal Nanoparticles by Microwave-assisted Chemical Reduction and Evaluation as Catalysts for Nitrile Hydrogenation under Ambient Conditions

Nishida Yoshihide, Wada Yuichiro, Chaudhari Chandan, Sato Katsutoshi, Nagaoka Katsutoshi

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 62 巻 ( 5 ) 頁： 220 - 227 2019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：Journal of the Japan Petroleum Institute

Herein, we report a protocol for rapid preparation of uniformly sized Ru, Rh, Pd, Ir, and Pt nanoparticles stabilized by poly(N-vinyl-2-pyrrolidone) via microwave-assisted chemical reduction with ethanol. Although the boiling point of ethanol, which has high reduction ability, is much lower than the temperature required for metal cation reduction, this solvent could be used as a reductant because the preparation was carried out in a sealed vessel. All metal nanoparticles showed similar sizes and amounts of poly(N-vinyl-2-pyrrolidone). The crystallite size of the Pd and Pt nanoparticles could be controlled by changing the ethanol concentration. The catalytic performance of the prepared metal nanoparticles was evaluated for the hydrogenation of benzonitrile under ambient conditions (25 °C, 1 bar H2). Rh nanoparticles showed the highest benzonitrile conversion and highest selectivity for secondary imine product. Interestingly, the particle-size dependence of the catalytic activity of the Rh nanoparticles showed volcano-type behavior; that is, the second smallest Rh nanoparticles (3.3 nm) showed the highest activity, which was attributed to high metal surface area and high turnover frequency. Notably, this is the first report of nitrile hydrogenation to afford a secondary imine under ambient conditions.

DOI： 10.1627/jpi.62.220

マイクロ波液相還元法によって調製した Rh ナノ粒子の局所的な配位構造の解析査読有り

西田吉秀, 和田雄一郎, 佐藤勝俊, 永岡勝俊

日本電磁波エネルギー応用学会論文誌 3 巻 ( 0 ) 頁： 1 - 5 2019年

Ru/La0.5Pr0.5O1.75 Catalyst for Low-Temperature Ammonia Synthesis 査読有り

Ogura Yuta, Tsujimaru Kotoko, Sato Katsutoshi, Miyahara Shin-ichiro, Toriyama Takaaki, Yamamoto Tomokazu, Matsumura Syo, Nagaoka Katsutoshi

ACS SUSTAINABLE CHEMISTRY & ENGINEERING 6 巻 ( 12 ) 頁： 17258 - 17266 2018年12月

Combined theoretical and experimental studies of CO oxidation on PdRu nanoalloys 査読有り

Zulkifli Nor Diana Bt., Ishimoto Takayoshi, Sato Katsutoshi, Eboshi Takaaki, Nagaoka Katsutoshi, Koyama Michihisa

APPLIED CATALYSIS A-GENERAL 568 巻頁： 176 - 182 2018年11月

Photocatalytic chemoselective cleavage of C-O bonds under hydrogen gas- and acid-free conditions

Imamura Kazuya, Kato Hiroko, Wada Yuichiro, Makabe Kazuhiro, Onda Ayumu, Tanaka Atsuhiro, Kominami Hiroshi, Sato Katsutoshi, Nagaoka Katsutoshi

CHEMICAL COMMUNICATIONS 54 巻 ( 53 ) 頁： 7298 - 7301 2018年7月

Selective Hydrogenation of Nitriles to Secondary Imines over Rh-PVP Catalyst under Mild Conditions

Nishida Yoshihide, Chaudhari Chandan, Imatome Hirotaka, Sato Katsutoshi, Nagaoka Katsutoshi

CHEMISTRY LETTERS 47 巻 ( 7 ) 頁： 938 - 940 2018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：公益社団法人日本化学会

© 2018 The Chemical Society of Japan. Various metal nanoparticle catalysts (Ru, Rh, Pd, Ir, and Pt) were prepared via liquid-phase reduction and their activity was studied for selective hydrogenation of benzonitrile to corresponding secondary imine under mild conditions (3bar H2and 30°C). The Rh catalyst with particle size of 2.7 nm exhibited excellent activity for the hydrogenation of benzonitrile to secondary imine. The catalyst was reused and applied to transform various nitriles to corresponding secondary imines.

DOI： 10.1246/cl.180349

Efficient ammonia synthesis over a Ru/La0.5Ce0.5O1.75 catalyst pre-reduced at high temperature

Influence of the Crystal Structure of Titanium Oxide on the Catalytic Activity of Rh/TiO2 in Steam Reforming of Propane at Low Temperature 査読有り

Yu Lin, Sato Katsutoshi, Toriyama Takaaki, Yamamoto Tomokazu, Matsumura Syo, Nagaoka Katsutoshi

CHEMISTRY-A EUROPEAN JOURNAL 24 巻 ( 35 ) 頁： 8742-8746 2018年6月

Ogura Yuta, Sato Katsutoshi, Miyahara Shin-ichiro, Kawano Yukiko, Toriyama Takaaki, Yamamoto Tomokazu, Matsumura Syo, Hosokawa Saburo, Nagaoka Katsutoshi

CHEMICAL SCIENCE 9 巻 ( 8 ) 頁： 2230 - 2237 2018年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）

© 2018 The Royal Society of Chemistry. Ammonia is an important feedstock for producing fertiliser and is also a potential energy carrier. However, the process currently used for ammonia synthesis, the Haber-Bosch process, consumes a huge amount of energy; therefore the development of new catalysts for synthesising ammonia at a high rate under mild conditions (low temperature and low pressure) is necessary. Here, we show that Ru/La0.5Ce0.5O1.75pre-reduced at an unusually high temperature (650 °C) catalysed ammonia synthesis at extremely high rates under mild conditions; specifically, at a reaction temperature of 350 °C, the rates were 13.4, 31.3, and 44.4 mmol g-1h-1at 0.1, 1.0, and 3.0 MPa, respectively. Kinetic analysis revealed that this catalyst is free of hydrogen poisoning under the conditions tested. Electron energy loss spectroscopy combined with O2absorption capacity measurements revealed that the reduced catalyst consisted of fine Ru particles (mean diameter < 2.0 nm) that were partially covered with partially reduced La0.5Ce0.5O1.75and were dispersed on a thermostable support. Furthermore, Fourier transform infrared spectra measured after N2addition to the catalyst revealed that N2adsorption on Ru atoms that interacted directly with the reduced La0.5Ce0.5O1.75weakened the NN bond and thus promoted its cleavage, which is the rate-determining step for ammonia synthesis. Our results indicate that high-temperature pre-reduction of this catalyst, which consists of Ru supported on a thermostable composite oxide with a cubic fluorite structure and containing reducible cerium, resulted in the formation of many sites that were highly active for N2reduction by hydrogen.

DOI： 10.1039/c7sc05343f

Facile Synthesis of Size-controlled Rh Nanoparticles via Microwave-assisted Alcohol Reduction and Their Catalysis of CO Oxidation

Nishida Yoshihide, Sato Katsutoshi, Yamamoto Tomokazu, Wu Dongshuang, Kusada Kohei, Kobayashi Hirokazu, Matsumura Syo, Kitagawa Hiroshi, Nagaoka Katsutoshi

CHEMISTRY LETTERS 46 巻 ( 8 ) 頁： 1254 - 1257 2017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：公益社団法人日本化学会

Size-controlled Rh nanoparticles stabilized by poly(vinylpyrrolidone) were quickly synthesized via alcohol reduction. Microwave-assisted synthesis in closed vessels allowed alcohols with low-to-high boiling points to be used as reductants under the same preparation conditions. Pure ethanol has not been used previously because its boiling point is lower than the temperature required for Rh3+ reduction. Alcohols with relatively strong reduction ability were found to lead to smaller Rh nanoparticles. The ability to oxidize CO was enhanced as the Rh particle size decreased.

DOI： 10.1246/cl.170440

Supported Ni catalysts prepared from hydrotalcite-like compounds for the production of hydrogen by ammonia decomposition 査読有り

Solid-Solution Alloying of Immiscible Ru and Cu with Enhanced CO Oxidation Activity 査読有り

Huang Bo, Kobayashi Hirokazu, Yamamoto Tomokazu, Matsumura Syo, Nishida Yoshihide, Sato Katsutoshi, Nagaoka Katsutoshi, Kawaguchi Shogo, Kubota Yoshiki, Kitagawa Hiroshi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 139 巻 ( 13 ) 頁： 4643 - 4646 2017年4月

Carbon-free H-2 production from ammonia triggered at room temperature with an acidic RuO2/gamma-Al2O3 catalyst 査読有り

Nagaoka Katsutoshi, Eboshi Takaaki, Takeishi Yuma, Tasaki Ryo, Honda Kyoko, Imamura Kazuya, Sato Katsutoshi

SCIENCE ADVANCES 3 巻 ( 4 ) 頁： e1602747 2017年4月

Sato Katsutoshi, Abe Naruhiko, Kawagoe Takafumi, Miyahara Shin-ichiro, Honda Kyoko, Nagaoka Katsutoshi

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 42 巻 ( 10 ) 頁： 6610 - 6617 2017年3月

Electronic Structure Evolution with Composition Alteration of RhxCuy Alloy Nanoparticles

Palina Natalia, Sakata Osami, Kumara L. S. R., Song Chulho, Sato Katsutoshi, Nagaoka Katsutoshi, Komatsu Tokutaro, Kobayashi Hirokazu, Kusada Kohei, Kitagawa Hiroshi

SCIENTIFIC REPORTS 7 巻 ( 7 ) 頁： 41264 2017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：Springer Nature

組成が違っても触媒活性が同等な新規Rh-Cuナノ粒子の電子状態の観測 : 合金の複合的な電子状態が寄与することを示唆. 京都大学プレスリリース. 2017-01-30.

DOI： 10.1038/srep41264

A low-crystalline ruthenium nano-layer supported on praseodymium oxide as an active catalyst for ammonia synthesis 査読有り

Sato Katsutoshi, Imamura Kazuya, Kawano Yukiko, Miyahara Shin-ichiro, Yamamoto Tomokazu, Matsumura Syo, Nagaoka Katsutoshi

CHEMICAL SCIENCE 8 巻 ( 1 ) 頁： 674 - 679 2017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：Royal Society of Chemistry (RSC)

Ammonia is a crucial chemical feedstock for fertilizer production and is a potential energy carrier. However, the current method of synthesizing ammonia, the Haber–Bosch process, consumes a great deal of energy. To reduce energy consumption, a process and a substance that can catalyze ammonia synthesis under mild conditions (low temperature and low pressure) are strongly needed. Here we show that Ru/Pr2O3 without any dopant catalyzes ammonia synthesis under mild conditions at 1.8 times the rates reported with other highly active catalysts. Scanning transmission electron micrograph observations and energy dispersive X-ray analyses revealed the formation of low-crystalline nano-layers of ruthenium on the surface of Pr2O3. Furthermore, CO2 temperature-programmed desorption revealed that the catalyst was strongly basic. These unique structural and electronic characteristics are considered to synergistically accelerate the rate-determining step of NH3 synthesis, cleavage of the N[triple bond, length as m-dash]N bond. We expect that the use of this catalyst will be a starting point for achieving efficient ammonia synthesis.

DOI： 10.1039/c6sc02382g

その他リンク： http://orcid.org/0000-0003-1774-1537

First-Principles Calculation, Synthesis, and Catalytic Properties of Rh-Cu Alloy Nanoparticles 査読有り

Komatsu Tokutaro, Kobayashi Hirokazu, Kusada Kohei, Kubota Yoshiki, Takata Masaki, Yamamoto Tomokazu, Matsumura Syo, Sato Katsutoshi, Nagaoka Katsutoshi, Kitagawa Hiroshi

CHEMISTRY-A EUROPEAN JOURNAL 23 巻 ( 1 ) 頁： 57 - 60 2017年1月

Catalyst using Pd-Ru solid solution alloy fine particles 査読有り

Kitagawa Hiroshi, Kusada Kohei, Nagaoka Katsutoshi, Sato Katsutoshi, Kutubi M, Shahajahan

2016年9月

A Synthetic Pseudo-Rh: NOx Reduction Activity and Electronic Structure of Pd-Ru Solid-solution Alloy Nanoparticles 査読有り

Sato Katsutoshi, Tomonaga Hiroyuki, Yamamoto Tomokazu, Matsumura Syo, Zulkifli Nor Diana Binti, Ishimoto Takayoshi, Koyama Michihisa, Kusada Kohei, Kobayashi Hirokazu, Kitagawa Hiroshi, Nagaoka Katsutoshi

SCIENTIFIC REPORTS 6 巻 ( 6 ) 頁： 28265 2016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：Nature Publishing Group

ロジウムを凌駕する排ガス浄化触媒活性を有する新規合金ナノ粒子－元素間融合により電子状態を改変、優れたNOx還元活性の発現－. 京都大学プレスリリース. 2016-06-27.

DOI： 10.1038/srep28265

その他リンク： http://orcid.org/0000-0003-1774-1537

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 査読有り

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

CHEMCATCHEM 7 巻 ( 23 ) 頁： 3887 - 3894 2015年12月

Development of Efficient Cold-start Process for Oxidative Reforming of n-Butane for Fuel Cell Applications 査読有り

Nagaoka Katsutoshi, Sato Katsutoshi

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 58 巻 ( 5 ) 頁： 274 - 284 2015年9月

Influence of basic dopants on the activity of Ru/Pr6O11 for hydrogen production by ammonia decomposition 査読有り

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

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 39 巻 ( 35 ) 頁： 20731 - 20735 2014年12月

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

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

CHEMSUSCHEM 7 巻 ( 12 ) 頁： 3264 - 3267 2014年12月

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

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

DALTON TRANSACTIONS 43 巻 ( 29 ) 頁： 11295 - 11298 2014年8月

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 査読有り

Sato Katsutoshi, Adachi Kouhei, Takita Yusaku, Nagaoka Katsutoshi

CHEMCATCHEM 6 巻 ( 3 ) 頁： 784 - 789 2014年3月

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 査読有り

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

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 136 巻 ( 5 ) 頁： 1864 - 1871 2014年2月

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

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

ACS CATALYSIS 3 巻 ( 7 ) 頁： 1564 - 1572 2013年7月

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

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

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 135 巻 ( 15 ) 頁： 5493 - 5496 2013年4月

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

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

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 358 巻頁： 89 - 98 2012年6月

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

Nagaoka Katsutoshi, Sato Katsutoshi, Takita Yusaku

JOURNAL OF CATALYSIS 287 巻頁： 86 - 92 2012年3月

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 査読有り

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

CATALYSIS COMMUNICATIONS 12 巻 ( 15 ) 頁： 1396 - 1400 2011年9月

Oxidative Steam Reforming of Ethanol over Supported Ni Catalysts at Relatively Low Temperature 査読有り

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

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 54 巻 ( 5 ) 頁： 331 - 337 2011年9月

Highly Active Cs2O/Ru/Pr6O11 as a Catalyst for Ammonia Decomposition 査読有り

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

CHEMISTRY LETTERS 39 巻 ( 9 ) 頁： 918 - 919 2010年9月

Preparation and characterization of active Ni/MgO in oxidative steam reforming of n-C4H10 査読有り

Sato Katsutoshi, Sago Fumiaki, Nagaoka Katsutoshi, Takita Yusaku

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 35 巻 ( 11 ) 頁： 5393 - 5399 2010年6月

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

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

CHEMSUSCHEM 3 巻 ( 12 ) 頁： 1364 - 1366 2010年

Metal phosphate and fluoride catalysts active for hydrolysis of NF3 査読有り

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

CATALYSIS COMMUNICATIONS 11 巻 ( 3 ) 頁： 147 - 150 2009年11月

Mechanism of Promotion Effects of Ce added to AlPO4 Effective for CFC Decomposition 査読有り

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

KAGAKU KOGAKU RONBUNSHU 35 巻 ( 6 ) 頁： 623 - 632 2009年11月

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

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

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 34 巻 ( 19 ) 頁： 8046 - 8052 2009年10月

Initiation of Oxidative Reforming of Butane over Praseodymium Oxide Supported Ni Catalysts at Ambient Temperature 査読有り

Sato Katsutoshi, Nagaoka Katsutoshi, Nishiguchi Hiroyasu, Takita Yusaku

JOURNAL OF THE JAPAN PETROLEUM INSTITUTE 52 巻 ( 5 ) 頁： 295 - 296 2009年9月

Oxidative reforming of n-C4H10 triggered at ambient temperature over reduced Ni/CeO2 査読有り

Sato Katsutoshi, Adachi Kouhei, Nagaoka Katsutoshi, Nishiguchi Hiroyasu, Takita Yusaku

CATALYSIS COMMUNICATIONS 10 巻 ( 11 ) 頁： 1478 - 1481 2009年6月

Catalytic activity of rare earth phosphates for SF6 decomposition and promotion effects of rare earths added into AlPO4 査読有り

Kashiwagi Daishin, Takai Asami, Takubo Takeshi, Yamada Hisatoshi, Inoue Takanori, Nagaoka Katsutoshi, Takita Yusaku

JOURNAL OF COLLOID AND INTERFACE SCIENCE 332 巻 ( 1 ) 頁： 136 - 144 2009年4月

A novel nanotube of composite of calcium carbonate and calcium sulfate 査読有り

Sugihara Hisao, Inoue Kotaro, Nakayama Maiko, Inoue Takanori, Nagaoka Katsutoshi, Takita Yusaku

MATERIALS LETTERS 63 巻 ( 2 ) 頁： 322 - 324 2009年1月

Metal Phosphate Catalysts Effective for Degradation of Sulfur Hexafluoride 査読有り

Kashiwagi Daishin, Takai Asami, Takubo Takeshi, Nagaoka Katsutoshi, Inoue Takanori, Takita Yusaku

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH 48 巻 ( 2 ) 頁： 632 - 640 2009年1月

n-C4H10 autothermal reforming over MgO-supported base metal catalysts 査読有り

Sato Katsutoshi, Nagaoka Katsutoshi, Nishiguchi Hiroyasu, Takita Yusaku

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 34 巻 ( 1 ) 頁： 333 - 342 2009年1月

Oxidation of Rh/Ce0.5Zr0.5O2 Reduced under Mild Conditions as an Initiator of n-Butane Oxidative Reforming at Ambient Temperature 査読有り

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

CHEMSUSCHEM 2 巻 ( 11 ) 頁： 1032 - 1035 2009年

高温還元したRh/CeO2の自発的酸化によるn-ブタンの酸化的改質反応の常温駆動

佐藤勝俊, 福田渉, 中鋪勝太, 永岡勝俊, 西口宏泰, 瀧田祐作

水素エネルギーシステム 33 巻頁： 44 - 48 2008年12月

Addition of Al2O3 or Cr2O3 Promotes Metal Reduction in a CoO-NiO-MgO Solid Solution Catalyst for CH4/H2O Reforming 査読有り

Nagaoka Katsutoshi, Hashimoto Yusaku, Sato Katsutoshi, Wakatsuki Toshiya, Nishiguchi Hiroyasu, Takita Yusaku

CHEMISTRY LETTERS 37 巻 ( 9 ) 頁： 982 - 983 2008年9月

Anaerobic oxidation of isobutane I. Catalysis by Cu-V complex oxides 査読有り

Hikazudani Susumu, Kikutani Kayo, Nagaoka Katsutoshi, Inoue Takanori, Takita Yusaku

APPLIED CATALYSIS A-GENERAL 345 巻 ( 1 ) 頁： 65 - 72 2008年7月

Oxidative reforming of n-butane triggered by spontaneous oxidation of CeO2-x at ambient temperature 査読有り

Nagaoka Katsutoshi, Sato Katsutoshi, Fukuda Sho, Nakashiki Shota, Nishiguchi Hiroyasu, Lercher Johannes A., Takita Yusaku

CHEMISTRY OF MATERIALS 20 巻 ( 13 ) 頁： 4176 - 4178 2008年7月

Anaerobic oxidation of isobutane: Catalytic properties of MgV2O6 and Mg2V2O7 prepared by the molten method 査読有り

Takita Yusaku, Hikazudani Susumu, Soda Kazuya, Nagaoka Katsutoshi

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 280 巻 ( 1-2 ) 頁： 164 - 172 2008年2月

Synthesis of mesoporous, nanocrystalline lanthanum phosphate in the presence of citric acid and stearic acid 査読有り

Ho Li-Ngee, Nishiguchi Hiroyasu, Nagaoka Katsutoshi, Takita Yusaku

JOURNAL OF RARE EARTHS 25 巻 ( 6 ) 頁： 684 - 691 2007年12月

Highly active Ni/MgO in oxidative steam pre-reforming of n-butane for fuel cell application 査読有り

Nagaoka Katsutoshi, Sato Katsutoshi, Nishiguchl Hiroyasu, Takita Yusaku

CATALYSIS COMMUNICATIONS 8 巻 ( 11 ) 頁： 1807 - 1810 2007年11月

The Pr promotion effect on oxygen storage capacity of Ce-Pr oxides studied using a TAP reactor 査読有り

Song Zhaoxia, Liu Wei, Nishiguchi Hiroyasu, Takami Akihide, Nagaoka Katsutoshi, Takita Yusaku

APPLIED CATALYSIS A-GENERAL 329 巻頁： 86 - 92 2007年10月

Influence of support on catalytic behavior of nickel catalysts in oxidative steam prereforming of n-butane for fuel cell applications 査読有り

Nagaoka Katsutoshi, Sato Katsutoshi, Nishiguchi Hiroyasu, Takita Yusaku

APPLIED CATALYSIS A-GENERAL 327 巻 ( 2 ) 頁： 139 - 146 2007年8月

Promotion mechanism of co-existing NaCl in the synthesis of CaCO3 査読有り

Takita Yusaku, Eto Mayumi, Sugihara Hisao, Nagaoka Katsutoshi

MATERIALS LETTERS 61 巻 ( 14-15 ) 頁： 3083 - 3085 2007年6月

Synthesis of Ni3C nano-whisker from NiSO4 and sucrose by means of spray pyrolysis 査読有り

Kashiwagi Takeshi, Suzuki Naohisa, Niina Masashi, Nishiguchi Hiroyasu, Nagaoka Katsutoshi, Takita Yusaku

CHEMISTRY LETTERS 36 巻 ( 4 ) 頁： 512 - 513 2007年4月

Influence of calcination procedure on the catalytic property of sulfated zirconia 査読有り

Li Xuebing, Nagaoka Katsutoshi, Simon Laurent J., Olindo Roberta, Lercher Johannes A.

CATALYSIS LETTERS 113 巻 ( 1-2 ) 頁： 34 - 40 2007年1月

Redox properties of CeO2 and Pt-Rh/CeO2 studied by TAP method 査読有り

Song Zhaoxia, Nishiguchi Hiroyasu, Liu Wei, Yamada Hiroshi, Takami Akihide, Kudo Kumiko, Nagaoka Katsutoshi, Takita Yusaku

CATALYSIS LETTERS 111 巻 ( 3-4 ) 頁： 169 - 171 2006年11月

Synthesis and characterization of a series of mesoporous nanocrystalline lanthanides phosphate 査読有り

Ho Li-Ngee, Nishiguchi Hiroyasu, Nagaoka Katsutoshi, Takita Yusaku

JOURNAL OF POROUS MATERIALS 13 巻 ( 3-4 ) 頁： 237 - 244 2006年10月

Synthesis and characterization of molybdenum incorporated mesoporous aluminophosphate 査読有り

Ho Li-Ngee, Ikegawa Tasuku, Nishiguchi Hiroyasu, Nagaoka Katsutoshi, Takita Yusaku

APPLIED SURFACE SCIENCE 252 巻 ( 18 ) 頁： 6260 - 6268 2006年7月

Ni/(rare earth phosphate) as a new effective catalyst for autothermal reforming of methane 査読有り

Nagaoka Katsutoshi, Eiraku Toshikazu, Nishiguchi Hiroyasu, Takita Yusaku

CHEMISTRY LETTERS 35 巻 ( 6 ) 頁： 580 - 581 2006年6月

Anaerobic oxidation of isobutane II. Catalysis by Mg-V complex oxides 査読有り

Takita Y, Xia Q, Kikutani K, Soda K, Takami H, Nishiguchi H, Nagaoka K

JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL 248 巻 ( 1-2 ) 頁： 61 - 69 2006年4月

Synthesis of highly active sulfated zirconia by sulfation with SO3 査読有り

Li XB, Nagaoka K, Olindo R, Lercher JA

JOURNAL OF CATALYSIS 238 巻 ( 1 ) 頁： 39 - 45 2006年2月

Decomposition of chlorobenzene over phosphate and sulfate catalysts properties 査読有り

Takita Y, Sadatomi Y, Nishiguchi H, Nagaoka K

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 79 巻 ( 1 ) 頁： 145 - 148 2006年1月

Oxidative dehydrogenation of isobutane to isobutene III reaction mechanism over CePO4 catalyst 査読有り

Takita Y, Qing X, Takami A, Nishiguchi H, Nagaoka K

APPLIED CATALYSIS A-GENERAL 296 巻 ( 1 ) 頁： 63 - 69 2005年11月

Oxidative activation of n-butane on sulfated zirconia 査読有り

Li XB, Nagaoka K, Simon LJ, Olindo R, Lercher JA, Hofmann A, Sauer J

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 127 巻 ( 46 ) 頁： 16159 - 16166 2005年11月

Synthesis of a thermally stable mesoporous aluminophosphate by using sodium aluminate as precursor 査読有り

Ho LN, Yukushima S, Morikawa R, Asaka N, Nishiguchi H, Nagaoka K, Takita Y

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS 268 巻 ( 1-3 ) 頁： 40 - 44 2005年10月

Improved resistance against coke deposition of titania supported cobalt and nickel bimetallic catalysts for carbon dioxide reforming of methane 査読有り

Takanabe K, Nagaoka K, Aika K

CATALYSIS LETTERS 102 巻 ( 3-4 ) 頁： 153 - 157 2005年8月

Mechanism of butane skeletal isomerization on sulfated zirconia 査読有り

Li XB, Nagaoka K, Simon LJ, Olindo R, Lercher JA

JOURNAL OF CATALYSIS 232 巻 ( 2 ) 頁： 456 - 466 2005年6月

Titania-supported cobalt and nickel bimetallic catalysts for carbon dioxide reforming of methane 査読有り

Takanabe K, Nagaoka K, Nariai K, Aika K

JOURNAL OF CATALYSIS 232 巻 ( 2 ) 頁： 268 - 275 2005年6月

Novel tough catalyst supports for reactions involving HF 査読有り

Takita Y, Ohkuma T, Nishiguchi H, Nagaoka K, Nakajo T

APPLIED CATALYSIS A-GENERAL 283 巻 ( 1-2 ) 頁： 47 - 52 2005年4月

Oxidation of isobutane over complex oxides containing V, Nb, Ta, and Mo under aerobic and anaerobic reaction conditions 査読有り

Takita Y, Kikutani K, Xia C, Takami H, Nagaoka K

APPLIED CATALYSIS A-GENERAL 283 巻 ( 1-2 ) 頁： 209 - 216 2005年4月

Influence of reduction temperature on the catalytic behavior of Co/TiO2 catalysts for CH4/CO2 reforming and its relation with titania bulk crystal structure 査読有り

Takanabe K, Nagaoka K, Nariai K, Aika K

JOURNAL OF CATALYSIS 230 巻 ( 1 ) 頁： 75 - 85 2005年2月

Interaction between sulfated zirconia and alkanes: prerequisites for active sites - formation and stability of reaction intermediates 査読有り

Li XB, Nagaoka K, Simon LJ, Lercher JA, Wrabetz S, Jentoft FC, Breitkopf C, Matysik S, Papp H

JOURNAL OF CATALYSIS 230 巻 ( 1 ) 頁： 214 - 225 2005年2月

Methane autothermal reforming with and without ethane over mono- and bimetal catalysts prepared from hydrotalcite precursors 査読有り

Nagaoka K, Jentys A, Lercher JA

JOURNAL OF CATALYSIS 229 巻 ( 1 ) 頁： 185 - 196 2005年1月

Improvement of Pt/ZrO2 by CeO2 for high pressure CH4/CO2 reforming 査読有り

Nagaoka K, Seshan K, Takanabe K, Aika K

CATALYSIS LETTERS 99 巻 ( 1-2 ) 頁： 97 - 100 2005年1月

Labile sulfates as key components in active sulfated zirconia for n-butane isomerization at low temperatures 査読有り

Li XB, Nagaoka K, Lercher JA

JOURNAL OF CATALYSIS 227 巻 ( 1 ) 頁： 130 - 137 2004年10月

Modification of Co/TiO2 for dry reforming of methane at 2 MPa by Pt, Ru or Ni 査読有り

Nagaoka K, Takanabe K, Aika K

APPLIED CATALYSIS A-GENERAL 268 巻 ( 1-2 ) 頁： 151 - 158 2004年8月

Co/TiO<inf>2</inf>catalyst for high pressure dry reforming of methane and its modification by other metals 査読有り

Katsutoshi Nagaoka, Kazuhiro Takanabe, Ken Ichi Aika, Ken Ichi Aika

Studies in Surface Science and Catalysis 147 巻頁： 187-192 2004年1月

記述言語：英語掲載種別：研究論文（学術雑誌）

Catalytic behaviour of 0.5wt%Co/TiO2, prepared from TiO2containing only anatase phase, in CH4/CO2reforming at 2 MPa was strongly affected by reduction temperature. Co/TiO2reduced at relatively lower temperatures (<1123 K) lost all of its activity at the beginning of the reaction, whereas the catalyst reduced at higher temperatures (1123 K) showed relatively stable activity with only a slight amount of deposited coke. However, the latter catalyst lost all of activities at a higher space velocity after the reaction for 20 h, mainly due to oxidation of metallic Co. The addition of trace amounts of noble metals (Pt or Ru) improved the catalytic stability drastically by retarding the oxidation. It was confirmed that the strong resistant nature of Co/TiO2to coke deposition was retained after the addition of the noble metals.