Dynamics of Reaction‐Induced Changes of Model‐Type Iron Oxide Phases in the CO2‐Fischer‐Tropsch‐Synthesis
Year: 2022
Type: article
Abstract: Iron‐based catalysts are employed in CO2‐FTS due to their ability to convert CO2 into CO in a first step and their selectivity towards higher hydrocarbons in a second CO hydrogenation step. According to the literature, iron carbides represent the active phase for hydrocarbon formation and are claimed to emerge in the presence of CO. We propose nanostructured FeOx films as model systems to assess information about the complex phase transformations during CO2‐FTS. Mesoporous hematite, ferrihydrite, maghemite, maghemite/magnetite films were exposed to CO2‐FTS atmospheres at 20 bar and 300 °C. Up to three distinct phases were observed depending on the time‐on‐stream (TOS): a sintered maghemite/magnetite phase, a carbidic core‐shell structure, and a low‐crystalline, needle‐type oxide phase. Our findings indicate that the formation of an intermediary maghemite/magnetite phase, predominant after short TOS (30 h), precedes the evolution of the carbide phase. Yet, even after prolonged TOS (185 h), no full conversion into a bulk carbide is observed.
Source: ChemCatChem
Language: English
Subfield: Catalysis
Field: Chemical Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
Estimated APC paid: $4,000
Awards: Febasierte Katalysatoren für die Umwandlung von CO2 zu höheren Kohlenwasserstoffen unter dynamischen Bedingungen, Verbundvorhaben ATO-KAT: Atomar dünn beschichtete poröse Elektroden als neuartige Katalysatoren für die Wasser-Elektrolyse: - leitfähige Träger und Elektrochemie -, G7112107, G755626601
OpenAlex ID: W4280648757