Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis

Handle URI:
http://hdl.handle.net/10754/627586
Title:
Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis
Authors:
Wezendonk, Tim A.; Sun, Xiaohui; Dugulan, A. Iulian; van Hoof, Arno J.F.; Hensen, Emiel J.M.; Kapteijn, Freek; Gascon, Jorge ( 0000-0001-7558-7123 )
Abstract:
Iron carbides are unmistakably associated with the active phase for Fischer-Tropsch synthesis (FTS). The formation of these carbides is highly dependent on the catalyst formulation, the activation method and the operational conditions. Because of this highly dynamic behavior, studies on active phase performance often lack the direct correlation between catalyst performance and iron carbide phase. For the above reasons, an extensive in situ Mössbauer spectroscopy study on highly dispersed Fe on carbon catalysts (Fe@C) produced through pyrolysis of a Metal Organic Framework was coupled to their FTS performance testing. The preparation of Fe@C catalysts via this MOF mediated synthesis allows control over the active phase formation and therefore provides an ideal model system to study the performance of different iron carbides. Reduction of fresh Fe@C followed by low-temperature Fischer-Tropsch (LTFT) conditions resulted in the formation of the ε′-Fe2.2C, whereas carburization of the fresh catalysts under high-temperature Fischer-Tropsch (HTFT) resulted in the formation of χ-Fe5C2. Furthermore, the different activation methods did not alter other important catalyst properties, as pre- and post-reaction transmission electron microscopy (TEM) characterization confirmed that the iron nanoparticle dispersion was preserved. The weight normalized activities (FTY) of χ-Fe5C2 and ε′-Fe2.2C are virtually identical, whilst it is found that ε′-Fe2.2C is a better hydrogenation catalyst than χ-Fe5C2. The absence of differences under subsequent HTFT experiments, where χ-Fe5C2 is the dominating phase, is a strong indication that the iron carbide phase is responsible for the differences in selectivity.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Chemical and Biological Engineering Program; KAUST Catalysis Center (KCC)
Citation:
Wezendonk TA, Sun X, Dugulan AI, van Hoof AJF, Hensen EJM, et al. (2018) Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis. Journal of Catalysis 362: 106–117. Available: http://dx.doi.org/10.1016/j.jcat.2018.03.034.
Publisher:
Elsevier BV
Journal:
Journal of Catalysis
Issue Date:
19-Apr-2018
DOI:
10.1016/j.jcat.2018.03.034
Type:
Article
ISSN:
0021-9517
Sponsors:
TAW wishes to thank the TU Delft central library staff in their quest for locating the antique literature cited in this paper.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0021951718301350
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical and Biological Engineering Program; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorWezendonk, Tim A.en
dc.contributor.authorSun, Xiaohuien
dc.contributor.authorDugulan, A. Iulianen
dc.contributor.authorvan Hoof, Arno J.F.en
dc.contributor.authorHensen, Emiel J.M.en
dc.contributor.authorKapteijn, Freeken
dc.contributor.authorGascon, Jorgeen
dc.date.accessioned2018-04-23T12:31:06Z-
dc.date.available2018-04-23T12:31:06Z-
dc.date.issued2018-04-19en
dc.identifier.citationWezendonk TA, Sun X, Dugulan AI, van Hoof AJF, Hensen EJM, et al. (2018) Controlled formation of iron carbides and their performance in Fischer-Tropsch synthesis. Journal of Catalysis 362: 106–117. Available: http://dx.doi.org/10.1016/j.jcat.2018.03.034.en
dc.identifier.issn0021-9517en
dc.identifier.doi10.1016/j.jcat.2018.03.034en
dc.identifier.urihttp://hdl.handle.net/10754/627586-
dc.description.abstractIron carbides are unmistakably associated with the active phase for Fischer-Tropsch synthesis (FTS). The formation of these carbides is highly dependent on the catalyst formulation, the activation method and the operational conditions. Because of this highly dynamic behavior, studies on active phase performance often lack the direct correlation between catalyst performance and iron carbide phase. For the above reasons, an extensive in situ Mössbauer spectroscopy study on highly dispersed Fe on carbon catalysts (Fe@C) produced through pyrolysis of a Metal Organic Framework was coupled to their FTS performance testing. The preparation of Fe@C catalysts via this MOF mediated synthesis allows control over the active phase formation and therefore provides an ideal model system to study the performance of different iron carbides. Reduction of fresh Fe@C followed by low-temperature Fischer-Tropsch (LTFT) conditions resulted in the formation of the ε′-Fe2.2C, whereas carburization of the fresh catalysts under high-temperature Fischer-Tropsch (HTFT) resulted in the formation of χ-Fe5C2. Furthermore, the different activation methods did not alter other important catalyst properties, as pre- and post-reaction transmission electron microscopy (TEM) characterization confirmed that the iron nanoparticle dispersion was preserved. The weight normalized activities (FTY) of χ-Fe5C2 and ε′-Fe2.2C are virtually identical, whilst it is found that ε′-Fe2.2C is a better hydrogenation catalyst than χ-Fe5C2. The absence of differences under subsequent HTFT experiments, where χ-Fe5C2 is the dominating phase, is a strong indication that the iron carbide phase is responsible for the differences in selectivity.en
dc.description.sponsorshipTAW wishes to thank the TU Delft central library staff in their quest for locating the antique literature cited in this paper.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0021951718301350en
dc.rightsNOTICE: this is the author’s version of a work that was accepted for publication in Journal of Catalysis. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Catalysis, [, , (2018-04-19)] DOI: 10.1016/j.jcat.2018.03.034 . © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/en
dc.subjectFischer Tropsch Synthesisen
dc.subjectFe catalysisen
dc.subjectMetal organic frameworken
dc.subjectMOF mediated synthesisen
dc.titleControlled formation of iron carbides and their performance in Fischer-Tropsch synthesisen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical and Biological Engineering Programen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.identifier.journalJournal of Catalysisen
dc.eprint.versionPost-printen
dc.contributor.institutionChemical Engineering, Catalysis Engineering Section, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlandsen
dc.contributor.institutionFundamental Aspects of Materials and Energy, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlandsen
dc.contributor.institutionEindhoven University of Technology, Inorganic Materials Chemistry, Helix 14, STW 4.33, Groene Loper 5, 5612 AE Eindhoven, The Netherlandsen
kaust.authorWezendonk, Tim A.en
kaust.authorGascon, Jorgeen
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