研究者詳細 - 永岡　勝俊

論文 - 永岡　勝俊

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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 招待有り査読有り

Kohei Era, Katsutoshi Sato, Shin-ichiro Miyahara, Takahiro Naito, Kanishka De Silva, Saeid Akrami, Hiroshi Yamada, Takaaki Toriyama, Tomokazu Yamamoto, Yasukazu Murakami, Ken-ichi Aika, Koji Inazu, Katsutoshi Nagaoka

ChemSusChem 16 巻 ( 22 ) 頁： e202300942 2023年10月

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

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

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

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

Chandan Chaudhari, Katsutoshi Sato, Shin-ichiro Miyahara, Tomokazu Yamamoto, Takaaki Toriyama, Syo Matsumura, Kohei Kusuda, Hiroshi Kitagawa, Katsutoshi Nagaoka

CHEMCATCHEM 2022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：WILEY-V C H VERLAG GMBH

Supported Ru catalysts were prepared by using different Ru precursors and examined for the hydrogenation of benzaldehyde to CHM. The catalyst prepared from Ru-3(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. Ru-CO/HT catalyst was tolerant to different functional groups and was stable until 7(th) cycle of recycle study.

DOI： 10.1002/cctc.202200241

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

Sato Katsutoshi, Zaitsu Shuhei, Kitayama Godai, Yagi Sho, Kayada Yuto, Nishida Yoshihide, Wada Yuichiro, Nagaoka Katsutoshi

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 2 巻 ( 7 ) 頁： 1627 - 1637 2022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：Journal of the American Chemical Society

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 NH3 and the mechanism of suppression of the deactivation by adding Pt (Pt/Ru/α-Al2O3). We found that nitric oxide (NO) produced by oxidation of NH3 induces oxidation of the Ru nanoparticle surface, which deactivates the catalyst via a three-step process: First, NO directly adsorbs on Ru0 to 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 Ru0 starting 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

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：日本語掲載種別：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

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：日本語掲載種別：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

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：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

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

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

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

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：日本語掲載種別：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 Chandan, Sato Katsutoshi, Ikeda Yasuyuki, Terada Kenji, Abe Naoya, Nagaoka Katsutoshi

NEW JOURNAL OF CHEMISTRY 45 巻 ( 22 ) 頁： 9743 - 9746 2021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：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：日本語掲載種別：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

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

<p>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.</p>

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 Kohei, Yamamoto Tomokazu, Toriyama Takaaki, Matsumura Syo, Sato Katsutoshi, Nagaoka Katsutoshi, Terada Kenji, Ikeda Yasuyuki, Hirai Yoshinari, Kitagawa Hiroshi

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

Chaudhari Chandan, Sato Katsutoshi, Nishida Yoshihide, Yamamoto Tomokazu, Toriyama Takaaki, Matsumura Syo, Ikeda Yasuyuki, Terada Kenji, Abe Naoya, Kusuda Kohei, Kitagawa Hiroshi, Nagaoka Katsutoshi

RSC ADVANCES 10 巻 ( 72 ) 頁： 44191 - 44195 2020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：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 Chandan, Shiraishi Masaya, Nishida Yoshihide, Sato Katsutoshi, Nagaoka Katsutoshi

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

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

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

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

Oxidation of Ru/Ce0.5Zr0.5O2-x at Ambient Temperature as a Trigger for Carbon-Free H-2 Production by Ammonia Oxidative Decomposition 査読有り

Matsunaga Takahiro, Matsumoto Suguru, Tasaki Ryo, Ogura Yuta, Eboshi Takaaki, Takeishi Yuma, Honda Kyoko, Sato Katsutoshi, Nagaoka Katsutoshi

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

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

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

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

Chaudhari Chandan, Sato Katsutoshi, Ogura Yuta, Miayahara Shin-Ichiro, Nagaoka Katsutoshi

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

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