Elucidating the Nature of Fe Species during Pyrolysis of the Fe-BTC MOF into Highly Active and Stable Fischer–Tropsch Catalysts
| Autor: | Freek Kapteijn, Ard C. J. Koeken, Gopinathan Sankar, Matthijs Ruitenbeek, Quirinus S. E. Warringa, Husn-Ubayda Islam, Adam Chojecki, Michiel Makkee, Maxim A. Nasalevich, A. Iulian Dugulan, Garry R. Meima, Vera P. Santos, Jorge Gascon, Tim A. Wezendonk |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Chemistry
Inorganic chemistry Nanoparticle Fischer–Tropsch process 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences Carbide chemistry.chemical_compound Metal-organic framework Trimesic acid 0210 nano-technology Pyrolysis Syngas |
| Zdroj: | ACS Catalysis. 6:3236-3247 |
| ISSN: | 2155-5435 |
| Popis: | In this combined in situ XAFS, DRIFTS, and Mossbauer study, we elucidate the changes in structural, electronic, and local environments of Fe during pyrolysis of the metal organic framework Fe-BTC toward highly active and stable Fischer–Tropsch synthesis (FTS) catalysts (Fe@C). Fe-BTC framework decomposition is characterized by decarboxylation of its trimesic acid linker, generating a carbon matrix around Fe nanoparticles. Pyrolysis of Fe-BTC at 400 °C (Fe@C-400) favors the formation of highly dispersed epsilon carbides (e′-Fe2.2C, dp = 2.5 nm), while at temperatures of 600 °C (Fe@C-600), mainly Hagg carbides are formed (χ-Fe5C2, dp = 6.0 nm). Extensive carburization and sintering occur above these temperatures, as at 900 °C the predominant phase is cementite (θ-Fe3C, dp = 28.4 nm). Thus, the loading, average particle size, and degree of carburization of Fe@C catalysts can be tuned by varying the pyrolysis temperature. Performance testing in high-temperature FTS (HT-FTS) showed that the initial turnover fr... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|