Updated on 2024/06/10


Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Research Associate


  • Young Researcher Support for attending ICC2024

    2024.04   the International Association of Catalysis Societies  

  • 優秀ポスター賞

    2022.08   Post Symposium of TOCAT9  

  • Oral Presentation Award

    2022.08   The 12th International Conference on Environmental Catalysis (ICEC2022)  

  • 優秀ポスター発表賞

    2021.12   第11 回CSJ 化学フェスタ 2021  

  • 優秀ポスター発表賞

    2021.08   触媒学会第41回夏の研修会  



  • Electric field-assisted NSR process for lean NOx reduction at low temperatures

    Ayaka Shigemoto, Yuki Inoda, Chihiro Ukai, Takuma Higo, Kohei Oka, Yasushi Sekine

    Chemical Communications    2024


  • Elucidation of catalytic NO<inf>x</inf> reduction mechanism in an electric field at low temperatures

    Ayaka Shigemoto, Takuma Higo, Yuki Narita, Seiji Yamazoe, Toru Uenishi, Yasushi Sekine

    Catalysis Science and Technology   12 ( 14 ) 4450 - 4455  2022.03

     View Summary

    As automobiles increasingly become electrically driven and as more engines and motors are used together, the exhaust temperatures of internal combustion engines are decreasing. Further improvement of exhaust gas purification catalyst performance is necessary. To purify nitrogen oxides, unburned hydrocarbons, and carbon monoxide simultaneously at low temperatures, electrothermal heating and plasma catalysis have been proposed, but these methods require high power consumption. Results of this study indicate that a direct current electric field applied to a Pd-supported catalyst shows high purification rates even at temperatures lower than 473 K under TWC conditions (NO-CO-C3H6-O2-H2O). For clarifying the reaction mechanism in this process, the adsorption of reactants was evaluated using in situ DRIFTS measurements in an electric field. Factors that improve the activity at low temperatures in the electric field were clarified.



  • Electrical promotion-assisted automotive exhaust catalyst: highly active and selective NO reduction to N<inf>2</inf>at low-temperatures

    Yuki Omori, Ayaka Shigemoto, Kohei Sugihara, Takuma Higo, Toru Uenishi, Yasushi Sekine

    Catalysis Science and Technology   11 ( 12 ) 4008 - 4011  2021.06

     View Summary

    A Pd catalyst (Pd/Ce0.7Zr0.3O2) in an electric field exhibits extremely high three-way catalytic activity (TWC: NO-C3H6-CO-O2-H2O). By applying an electric field to the semiconductor catalyst, low-temperature operation of TWC can be achieved even at 473 K by virtue of the activated surface-lattice oxygen.



  • Three-Way Catalytic Reaction in an Electric Field for Exhaust Emission Control Application

    Toru Uenishi, Ayaka Shigemoto, Yuki Omori, Takuma Higo, Shuhei Ogo, Yasushi Sekine

    SAE Technical Papers   ( 2021 )  2021

     View Summary

    To prevent global warming, further reductions in carbon dioxide are required. It is therefore important to promote the spread of electric vehicles powered by internal combustion engines and electric vehicles without internal combustion engines. As a result, emissions from hybrid electric vehicles equipped with internal combustion engines should be further reduced. Interest in catalytic reactions in an electric field with a higher catalytic activity compared to conventional catalysts has increased because this technology consumes less energy than other electrical heating devices. This study was therefore undertaken to apply a catalytic reaction in an electric field to an exhaust emission control. First, the original experimental equipment was built with a high voltage system used to conduct catalytic activity tests. Second, experiments with palladium cerium-zirconium oxide support catalysts showed that a three-way catalytic activity in an electric field could be found. at lower exhaust temperatures than conventional catalysts. Then it became clear that catalytic compositions that include semiconductor properties are a key for researching and developing this technology. In addition, applied electrical current control has been shown to be another focus of research and development. Finally, experimental results with several reducing species demonstrate that the electron-promoted surface proton and lattice oxygen greatly contributed to catalytic activity in an electric field.



  • Promotive effect of H<inf>2</inf>O on low-temperature NO reduction by CO over Pd/La<inf>0.9</inf>Ba<inf>0.1</inf>AlO<inf>3-</inf><inf>δ</inf>

    Takuma Higo, Yuki Omori, Ayaka Shigemoto, Kohei Ueno, Shuhei Ogo, Yasushi Sekine

    Catalysis Today   352   192 - 197  2020.08

     View Summary

    For future removal of NOx by catalysts, low-temperature NO reduction is desired. Results confirmed that a drastic improvement of catalytic activity by H2O on NO–CO–O2 reaction over Pd/La0.9Ba0.1AlO3-δ catalyst at the low temperature of 473 K or below. In a humidified condition, NO reaction with CO on Pd/La0.9Ba0.1AlO3-δ proceeded without being affected by competitive adsorption of NO and CO, whereas that on Pd/Al2O3 was inhibited by strong adsorption of CO on a Pd surface. From in-situ DRIFTS measurements, results showed that nitrite species on the support react with CO adsorbed onto Pd at the periphery of Pd particles and that carbonate species accumulated on Pd/La0.9Ba0.1AlO3-δ are removed rapidly in a humidified condition. Although NO reduction proceeds dominantly on the Pd surface in a dry condition, supplied steam promotes desorption of the surface carbonate to advance the reaction of nitrite with CO for de-NOx in a humidified condition. This mechanism occurs specifically on Pd/La0.9Ba0.1AlO3-δ by virtue of the lattice oxygen and oxygen vacancy on La0.9Ba0.1AlO3-δ.




Research Projects

  • 電場アシスト触媒による低温での亜酸化窒素直接分解プロセス

    日本学術振興会  科学研究費助成事業

    Project Year :


    重本 彩香


  • 直流電場を印加させた三元触媒の低温域におけるNOx還元反応のメカニズム解明

    成田優希, 重本彩香, 比護拓馬, 植西徹, 関根泰

    触媒討論会討論会A予稿集(CD-ROM)   130th  2022


  • Research on Post Treatment System with a Catalytic Activity in an Electric Field

    Uenishi Toru, Shigemoto Ayaka, Omori Yuki, Higo Takuma, Ogo Shuhei, Sekine Yasushi

    Transactions of Society of Automotive Engineers of Japan   52 ( 2 ) 251 - 256  2021

     View Summary

    A catalytic activity in an electric field was researched for further lower cost and more compact exhaust gas control system of plug-in hybrid electric vehicle than electrically heated catalyst system. Firstly, an experimental equipment and test protocol for an electric field was constructed. Secondly, it was confirmed that the catalytic activity in an electric field with palladium-ceria-zirconia complex oxide catalyst was occurred in the low temperature range where the conventional catalytic reaction was inactive. Finally, it was found that the catalytic activity in an electric field could be optimized by the catalyst specifications and the electric current.

    DOI CiNii

  • Research on aftertreatment system with electric field assisted catalyst

    植西徹, 重本彩香, 大森裕貴, 比護拓馬, 小河脩平, 関根泰

    自動車技術会大会学術講演会講演予稿集(Web)   2020  2020


  • 電場印加反応場における低温での三元触媒反応

    重本彩香, 大森裕貴, 比護拓馬, 小河脩平, 植西徹, 関根泰

    触媒討論会討論会A予稿集(CD-ROM)   126th  2020


  • 水蒸気共存下におけるNOx還元反応の低温化

    重本彩香, 大森裕貴, 比護拓馬, 小河脩平, 関根泰

    石油・石油化学討論会講演要旨   49th (Web)  2019