In-situ probing of the Fischer-Tropsch reaction on Co single crystal surfaces up to 1 bar.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39856064.
- Also identified by DOI 10.1038/s41467-025-56082-8 and PMC identifier 11761050.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The surface chemistry of the Fischer-Tropsch catalytic reaction over Co has still several unknows. Here, we report an in-situ X-ray photoelectron spectroscopy study of Co <math xmlns="http://www.w3.org/1998/Math/MathML"> <mfenced><mrow><mn>0001</mn></mrow> </mfenced> </math> and Co( <math xmlns="http://www.w3.org/1998/Math/MathML"><mn>10</mn> <mover><mrow><mn>1</mn></mrow> <mo>¯</mo></mover> <mn>4</mn></math> ), and in-situ high energy surface X-ray diffraction of Co <math xmlns="http://www.w3.org/1998/Math/MathML"> <mfenced><mrow><mn>0001</mn></mrow> </mfenced> <mo>,</mo></math> during the Fischer-Tropsch reaction at 0.15 bar - 1 bar and 406 K - 548 K in a H<sub>2</sub>/CO gas mixture. We find that these Co surfaces remain metallic under all conditions and that the coverage of chemisorbed species ranges from 0.4-1.7 monolayers depending on pressure and temperature. The adsorbates include CO on-top, C/-C<sub>x</sub>H<sub>y</sub> and various longer hydrocarbon molecules, indicating a rate-limiting direct CO dissociation pathway and that only hydrocarbon species participate in the chain growth. The accumulation of hydrocarbon species points to the termination step being rate-limiting also. Furthermore, we demonstrate that the intermediate surface species are highly dynamic, appearing and disappearing with time delays after rapid changes in the reactants' composition.