東京大学・天文学教育研究センターでは2003年4月から談話会を開いています。
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ML: semiadm _at_ ioa.s.u-tokyo.ac.jp
please replace _at_ with @
Language: English
Abstract: Can industrial-style heterogeneous catalysis operate in the interstellar medium? Transition metals (TMs) are key players in terrestrial catalysis: their ability to coordinate a variety of ligands and activate otherwise inert molecules underpins processes such as Fischer–Tropsch (H₂ + CO) and Haber–Bosch (H₂ + N₂). In these systems, metallic surfaces act as heterogeneous catalysts that adsorb and transform reactant molecules. In astrochemistry, icy mantles on dust grains are often invoked as catalytic media, but their ability to open multiple, low-barrier reaction channels is limited compared to TM sites. Here we show that interstellar dust grains incorporating transition metals such as iron (Fe) and nickel (Ni) can display catalytic properties closely resembling terrestrial heterogeneous catalysts. Using density functional theory (DFT) simulations combined with kinetic modelling, we investigate Fischer–Tropsch-type chemistry on Fe-based catalytic sites under interstellar conditions. We consider supported single atoms and nanoclusters on silica (SiO₂) and silicon carbide (SiC), as well as mineral grains such as troilite (FeS). We find that the conversion of CO and H₂ into alcohols (e.g. methanol and ethanol), ketene, methane, and short hydrocarbon chains (ethene, ethane) is feasible within realistic temperature ranges, and that adsorption energies at TM sites are sufficient to retain key reactants. These results establish heterogeneous astrocatalysis by transition metals as a viable pathway for complex molecule formation, opening new synthetic routes for chemical and potentially prebiotic evolution in space.
| # | Date | Speaker | Title | Chair |
| 435 | 2025年12月4日(木) 15:30-16:30 | Gerard Pareras (Universitat Autònoma de Barcelona/University of Tokyo) | Transition-metal-driven heterogeneous astrocatalysis in the interstellar medium | 天文教室談話会と合同 (I. Sakon) |
| 436 | 2025年12月18日(木) 15:30-16:30 | Devendra Ojha (TIFR) | Accretion Outburst: A window to the innermost region of protoplanetary discs | I. Sakon |
| 437 | 2026年1月22日(木) 15:30-16:30 | Amit Pathak (Banaras Hindu University) | TBD | I. Sakon |
詳細はこちら: 令和7(2025)年度談話会
| # | Date | Speaker | Title | Chair |
| 434 | 2025年11月18日(火) 16:15-17:15 | Masahiro Machida (Kyushu University) | Star Formation Simulations from a Prestellar Core to the Class II Disk Stage | 天文教室談話会と共催 |
| 433 | 2025年10月31日(金) 15:30-16:30 | Joaquin Vieira (The University of Illinois at Urbana-Champaign) | The Terahertz Intensity Mapper | K. Kohno |
| 432 | 2025年10月6日(月) 15:30-16:30 | Patricio Rojo (Universidad de Chile) | Astronomy and Planetary Sciences at Universidad de Chile | K. Kohno |
| 431 | 2025年8月26日(火) 13:00-14:00 | Gaspar Bakos (Princeton) | Observing the Entire Visible Sky at High Precision with the HATPI Project | 国立天文台談話会と共同開催 |
| 430 | 2025年7月24日(木) 15:30-16:30 | Keiichi Ohnaka (Universidad Andrés Bello) | Milliarcsecond-resolution near-infrared interferometric imaging of the rapidly changing red supergiant WOH G64 in the Large Magellanic Cloud | I.Sakon |
| 429 | 2025年4月17日(木) 15:30-16:30 | Eduardo Ibar (Universidad de Valparaíso) | The properties of emitting line galaxies discovered by the JWST Emission Line Survey (JELS) | I.Sakon |