Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts

Muthu Kumaran Gnanamani; Gary Jacobs; Uschi M. Graham; Mauro C. Ribeiro; Fabio B. Noronha; Wilson D. Shafer; Burtron H. Davis

doi:10.1016/j.cattod.2015.08.047

Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts

Muthu Kumaran Gnanamani, Gary Jacobs, Uschi M. Graham, Mauro C. Ribeiro, Fabio B. Noronha, Wilson D. Shafer, Burtron H. Davis

Center for Applied Energy Research (CAER)

Research output: Contribution to journal › Article › peer-review

40 Scopus citations

Abstract

Fischer-Tropsch (FT) synthesis was performed over 15%Co/CeSi and 15Co/CeMnSi catalysts using a 1 L CSTR at 230 °C, 1.89 MPa and a H₂/CO ratio of 1.86. The oxygenate selectivity for both catalysts increased with increasing time-on-stream during FT synthesis. X-ray diffraction, EXAFS and HR-TEM analyses of fresh catalysts and those withdrawn during FT synthesis indicate that increases in the selectivity for oxygenates with time are related to structural changes in the catalyst, most likely associated with a transition from a metallic cobalt surface to one containing surface cobalt carbide. Moreover, a significant effect of carburization on increasing the selectivity for oxygenates was observed for FTS using the 15Co/CeMnSi catalyst. The reactivity of CO was inhibited by the presence of carbon on the surface of cobalt which promoted oxygenate formation through a CO insertion mechanism.

Original language	English
Pages (from-to)	40-47
Number of pages	8
Journal	Catalysis Today
Volume	261
DOIs	https://doi.org/10.1016/j.cattod.2015.08.047
State	Published - Mar 1 2016

Bibliographical note

Funding Information:
Support for this study was from the Commonwealth of Kentucky . M.C.R. thanks The Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the scholarship granted over the time this study was made.

Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.

Funding

Support for this study was from the Commonwealth of Kentucky . M.C.R. thanks The Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the scholarship granted over the time this study was made.

Funders	Funder number
Conselho Nacional de Desenvolvimento Científico e Tecnológico

Keywords

CeO support
CO insertion mechanism
Cobalt carbide
EXAFS-XANES
Fischer-Tropsch synthesis
HR-TEM
Oxygenates selectivity

ASJC Scopus subject areas

Catalysis
General Chemistry

Access to Document

10.1016/j.cattod.2015.08.047

Cite this

@article{4847850dec064aca85ce0abb841822d7,

title = "Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts",

abstract = "Fischer-Tropsch (FT) synthesis was performed over 15%Co/CeSi and 15Co/CeMnSi catalysts using a 1 L CSTR at 230 °C, 1.89 MPa and a H2/CO ratio of 1.86. The oxygenate selectivity for both catalysts increased with increasing time-on-stream during FT synthesis. X-ray diffraction, EXAFS and HR-TEM analyses of fresh catalysts and those withdrawn during FT synthesis indicate that increases in the selectivity for oxygenates with time are related to structural changes in the catalyst, most likely associated with a transition from a metallic cobalt surface to one containing surface cobalt carbide. Moreover, a significant effect of carburization on increasing the selectivity for oxygenates was observed for FTS using the 15Co/CeMnSi catalyst. The reactivity of CO was inhibited by the presence of carbon on the surface of cobalt which promoted oxygenate formation through a CO insertion mechanism.",

keywords = "CeO support, CO insertion mechanism, Cobalt carbide, EXAFS-XANES, Fischer-Tropsch synthesis, HR-TEM, Oxygenates selectivity",

author = "Gnanamani, {Muthu Kumaran} and Gary Jacobs and Graham, {Uschi M.} and Ribeiro, {Mauro C.} and Noronha, {Fabio B.} and Shafer, {Wilson D.} and Davis, {Burtron H.}",

note = "Funding Information: Support for this study was from the Commonwealth of Kentucky . M.C.R. thanks The Conselho Nacional de Desenvolvimento Cient{\'i}fico e Tecnol{\'o}gico (CNPq) for the scholarship granted over the time this study was made. Publisher Copyright: {\textcopyright} 2015 Elsevier B.V. All rights reserved.",

year = "2016",

month = mar,

day = "1",

doi = "10.1016/j.cattod.2015.08.047",

language = "English",

volume = "261",

pages = "40--47",

}

TY - JOUR

T1 - Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts

AU - Gnanamani, Muthu Kumaran

AU - Jacobs, Gary

AU - Graham, Uschi M.

AU - Ribeiro, Mauro C.

AU - Noronha, Fabio B.

AU - Shafer, Wilson D.

AU - Davis, Burtron H.

N1 - Funding Information: Support for this study was from the Commonwealth of Kentucky . M.C.R. thanks The Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for the scholarship granted over the time this study was made. Publisher Copyright: © 2015 Elsevier B.V. All rights reserved.

PY - 2016/3/1

Y1 - 2016/3/1

N2 - Fischer-Tropsch (FT) synthesis was performed over 15%Co/CeSi and 15Co/CeMnSi catalysts using a 1 L CSTR at 230 °C, 1.89 MPa and a H2/CO ratio of 1.86. The oxygenate selectivity for both catalysts increased with increasing time-on-stream during FT synthesis. X-ray diffraction, EXAFS and HR-TEM analyses of fresh catalysts and those withdrawn during FT synthesis indicate that increases in the selectivity for oxygenates with time are related to structural changes in the catalyst, most likely associated with a transition from a metallic cobalt surface to one containing surface cobalt carbide. Moreover, a significant effect of carburization on increasing the selectivity for oxygenates was observed for FTS using the 15Co/CeMnSi catalyst. The reactivity of CO was inhibited by the presence of carbon on the surface of cobalt which promoted oxygenate formation through a CO insertion mechanism.

AB - Fischer-Tropsch (FT) synthesis was performed over 15%Co/CeSi and 15Co/CeMnSi catalysts using a 1 L CSTR at 230 °C, 1.89 MPa and a H2/CO ratio of 1.86. The oxygenate selectivity for both catalysts increased with increasing time-on-stream during FT synthesis. X-ray diffraction, EXAFS and HR-TEM analyses of fresh catalysts and those withdrawn during FT synthesis indicate that increases in the selectivity for oxygenates with time are related to structural changes in the catalyst, most likely associated with a transition from a metallic cobalt surface to one containing surface cobalt carbide. Moreover, a significant effect of carburization on increasing the selectivity for oxygenates was observed for FTS using the 15Co/CeMnSi catalyst. The reactivity of CO was inhibited by the presence of carbon on the surface of cobalt which promoted oxygenate formation through a CO insertion mechanism.

KW - CeO support

KW - CO insertion mechanism

KW - Cobalt carbide

KW - EXAFS-XANES

KW - Fischer-Tropsch synthesis

KW - HR-TEM

KW - Oxygenates selectivity

UR - http://www.scopus.com/inward/record.url?scp=84948178272&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84948178272&partnerID=8YFLogxK

U2 - 10.1016/j.cattod.2015.08.047

DO - 10.1016/j.cattod.2015.08.047

M3 - Article

AN - SCOPUS:84948178272

SN - 0920-5861

VL - 261

SP - 40

EP - 47

JO - Catalysis Today

JF - Catalysis Today

ER -

Influence of carbide formation on oxygenates selectivity during Fischer-Tropsch synthesis over Ce-containing Co catalysts

Abstract

Bibliographical note

Funding

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this