Comprehensive atomistic simulations of Fischer-Tropsch in outer space : astrocatalysis by Fe13-supported nanoclusters on SiO2
Pareras Niell, Gerard (Universitat Autònoma de Barcelona. Departament de Química)
Cabedo Soto, Victoria (Heriot-Watt University. School of Engineering and Physical Sciences)
McCoustra, Martin (Heriot-Watt University. School of Engineering and Physical Sciences)
Rimola Gibert, Albert (Universitat Autònoma de Barcelona. Departament de Química)

Data:	2025
Resum:	Catalytic processes are fundamental not only to terrestrial chemistry (e. g. , in the synthesis of fuels, chemicals, and pharmaceuticals) but also to extraterrestrial chemistry, contributing to chemical reactions occurring in various astrophysical environments. In space, gas-phase reactions are limited due to sparse energy sources and the absence of a medium for energy dissipation, making heterogeneous catalysis on cosmic dust grains essential for driving chemical transformations. Iron nanoclusters (FeNCs) embedded on these grains present intriguing catalytic properties, especially for Fischer-Tropsch-type (FTT) reactions that synthesize interstellar organic compounds. This study investigates the formation of short-chain alcohols (CHOH and CHCHOH) and hydrocarbons (CH, CHCH and CHCH) through a FTT mechanism using as astrocatalyst a realistic model of an Fe nanocluster supported on a silica (SiO) surface (Fe@SiO) by characterizing the potential energy surfaces (PESs) and performing kinetics calculations. Comprehensive PESs grounded on density functional theory (DFT) reveal that direct CO dissociation on Fe@SiO (required to form CHCHOH and CH) is energetically unfavorable, but subsequent H addition facilitates CO bond cleavage, thus competing with the formation of CHOH. Moreover, kinetic analysis indicates that C-O dissociation is more favorable than CHOH synthesis, enabling chain-growing-based processes. Kinetics also predicts that the temperatures at which the FTT reactions can operate (i. e. , above 100 K) are those available in protostellar regions and in evolved stages during a Solar-type planetary system formation (e. g. , protoplanetary disks and primitive planetary environments). These findings offer a new proof on the feasibility of Astrocatalysis (namely, true chemical catalysis in astrophysical environments), in this case exerted by FeNCs, which partly alleviate stringent conditions required for FT on Earth, this way proposing a potential FTT-supported catalysis under milder conditions in astrochemical contexts.
Ajuts:	European Commission 101105235 European Commission 865657 Agencia Estatal de Investigación CNS2023-144902 Agencia Estatal de Investigación PID2021-126427NB-I00
Nota:	Altres ajuts: acords transformatius de la UAB
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Atomistic simulations ; Catalytic process ; CH 4 ; Condition ; Energy source ; Fischer Tropsch ; Gas-phase reactions ; Outer space ; Potential-energy surfaces ; SiO 2
Publicat a:	Journal of physical chemistry. C, Vol. 129, issue 22 (June 2025) , p. 10069-10082, ISSN 1932-7455

DOI: 10.1021/acs.jpcc.5c01472
PMID: 40497144

14 p, 7.0 MB

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