Comprehensive Atomistic Simulations of Fischer–Tropsch in Outer Space: Astrocatalysis by Fe13–Supported Nanoclusters on SiO2
Year: 2025
Type: article
Abstract: 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 (CH 3 OH and CH 3 CH 2 OH) and hydrocarbons (CH 4, CH 2 CH 2 and CH 3 CH 3 ) through a FTT mechanism using as astrocatalyst a realistic model of an Fe 13 nanocluster supported on a silica (SiO 2 ) surface (Fe 13 @SiO 2 ) 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 13 @SiO 2 (required to form CH 3 CH 2 OH and CH 4 ) is energetically unfavorable, but subsequent H 2 addition facilitates CO bond cleavage, thus competing with the formation of CH 3 OH. Moreover, kinetic analysis indicates that C–O dissociation is more favorable than CH 3 OH 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.
Institutions: Universitat Autònoma de Barcelona, Heriot-Watt University
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4410528757