Fischer-Tropsch synthesis: Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts

Muthu Kumaran Gnanamani; Gary Jacobs; Venkat Ramana Rao Pendyala; Uschi M. Graham; Shelley D. Hopps; Gerald A. Thomas; Wilson D. Shafer; Dennis E. Sparks; Qunfeng Xiao; Yongfeng Hu; Burtron H. Davis

doi:10.1016/j.apcata.2016.05.024

Fischer-Tropsch synthesis: Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts

Muthu Kumaran Gnanamani, Gary Jacobs, Venkat Ramana Rao Pendyala, Uschi M. Graham, Shelley D. Hopps, Gerald A. Thomas, Wilson D. Shafer, Dennis E. Sparks, Qunfeng Xiao, Yongfeng Hu, Burtron H. Davis

Center for Applied Energy Research (CAER)

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

20 Scopus citations

Abstract

The effect of phosphorus addition on silica-supported cobalt catalyst was investigated for Fischer-Tropsch synthesis (FTS). As shown by STEM images and chemisorption, the addition of phosphorus to cobalt of up to 1 wt% increased the dispersion of cobalt. Further addition of phosphorus (e.g., 3 and 5 wt.%), as demonstrated by TPR, pulse reoxidation, and XANES, significantly hindered the reduction of cobalt oxides. The cobalt FTS catalysts containing 0.5 and 1.0 wt% P exhibited greater stability in comparison with undoped and 3.0 wt% P containing cobalt catalysts. Analysis of XANES spectra at the P and Co K-edges, along with DRIFTS results of H₂-activated cobalt catalysts, suggest that cobalt particles interact with PO₄³⁻ ions, indicating a role played by P in anchoring Co particles to the support, thus hindering the cobalt sintering rate. The initial selectivity to methane was slightly higher for 0.5%P-20%Co/SiO₂ and 1.0%P-20%Co/SiO₂ catalysts compared to the undoped catalyst, but at longer times differences were small. At higher loadings of P (3 wt.%), FT activity and selectivity were adversely and irreversibly affected.

Original language	English
Pages (from-to)	146-158
Number of pages	13
Journal	Applied Catalysis A: General
Volume	523
DOIs	https://doi.org/10.1016/j.apcata.2016.05.024
State	Published - Aug 5 2016

Bibliographical note

Funding Information:
This work carried out at the CAER was supported by the Commonwealth of Kentucky. Research described in this paper was performed in part at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.

Publisher Copyright:
© 2016 Elsevier B.V.

Funding

This work carried out at the CAER was supported by the Commonwealth of Kentucky. Research described in this paper was performed in part at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan.

Funders	Funder number
Government of Saskatchewan
University of Saskatchewan
Canadian Institutes of Health Research
Natural Sciences and Engineering Research Council of Canada
Western Economic Diversification Canada
National Research Council Canada (NRCC)
Canada Foundation for Innovation

Keywords

Cobalt
EXAFS/XANES
Fischer-Tropsch synthesis
Phosphorus
Promoter
Silica

ASJC Scopus subject areas

Catalysis
Process Chemistry and Technology

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10.1016/j.apcata.2016.05.024

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@article{d372819822e147f692245246e52fad9a,

title = "Fischer-Tropsch synthesis: Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts",

abstract = "The effect of phosphorus addition on silica-supported cobalt catalyst was investigated for Fischer-Tropsch synthesis (FTS). As shown by STEM images and chemisorption, the addition of phosphorus to cobalt of up to 1 wt% increased the dispersion of cobalt. Further addition of phosphorus (e.g., 3 and 5 wt.%), as demonstrated by TPR, pulse reoxidation, and XANES, significantly hindered the reduction of cobalt oxides. The cobalt FTS catalysts containing 0.5 and 1.0 wt% P exhibited greater stability in comparison with undoped and 3.0 wt% P containing cobalt catalysts. Analysis of XANES spectra at the P and Co K-edges, along with DRIFTS results of H2-activated cobalt catalysts, suggest that cobalt particles interact with PO43− ions, indicating a role played by P in anchoring Co particles to the support, thus hindering the cobalt sintering rate. The initial selectivity to methane was slightly higher for 0.5%P-20%Co/SiO2 and 1.0%P-20%Co/SiO2 catalysts compared to the undoped catalyst, but at longer times differences were small. At higher loadings of P (3 wt.%), FT activity and selectivity were adversely and irreversibly affected.",

keywords = "Cobalt, EXAFS/XANES, Fischer-Tropsch synthesis, Phosphorus, Promoter, Silica",

author = "Gnanamani, {Muthu Kumaran} and Gary Jacobs and Pendyala, {Venkat Ramana Rao} and Graham, {Uschi M.} and Hopps, {Shelley D.} and Thomas, {Gerald A.} and Shafer, {Wilson D.} and Sparks, {Dennis E.} and Qunfeng Xiao and Yongfeng Hu and Davis, {Burtron H.}",

note = "Funding Information: This work carried out at the CAER was supported by the Commonwealth of Kentucky. Research described in this paper was performed in part at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Publisher Copyright: {\textcopyright} 2016 Elsevier B.V.",

year = "2016",

month = aug,

day = "5",

doi = "10.1016/j.apcata.2016.05.024",

language = "English",

volume = "523",

pages = "146--158",

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TY - JOUR

T1 - Fischer-Tropsch synthesis

T2 - Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts

AU - Gnanamani, Muthu Kumaran

AU - Jacobs, Gary

AU - Pendyala, Venkat Ramana Rao

AU - Graham, Uschi M.

AU - Hopps, Shelley D.

AU - Thomas, Gerald A.

AU - Shafer, Wilson D.

AU - Sparks, Dennis E.

AU - Xiao, Qunfeng

AU - Hu, Yongfeng

AU - Davis, Burtron H.

N1 - Funding Information: This work carried out at the CAER was supported by the Commonwealth of Kentucky. Research described in this paper was performed in part at the Canadian Light Source, which is funded by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada, the National Research Council Canada, the Canadian Institutes of Health Research, the Government of Saskatchewan, Western Economic Diversification Canada, and the University of Saskatchewan. Publisher Copyright: © 2016 Elsevier B.V.

PY - 2016/8/5

Y1 - 2016/8/5

N2 - The effect of phosphorus addition on silica-supported cobalt catalyst was investigated for Fischer-Tropsch synthesis (FTS). As shown by STEM images and chemisorption, the addition of phosphorus to cobalt of up to 1 wt% increased the dispersion of cobalt. Further addition of phosphorus (e.g., 3 and 5 wt.%), as demonstrated by TPR, pulse reoxidation, and XANES, significantly hindered the reduction of cobalt oxides. The cobalt FTS catalysts containing 0.5 and 1.0 wt% P exhibited greater stability in comparison with undoped and 3.0 wt% P containing cobalt catalysts. Analysis of XANES spectra at the P and Co K-edges, along with DRIFTS results of H2-activated cobalt catalysts, suggest that cobalt particles interact with PO43− ions, indicating a role played by P in anchoring Co particles to the support, thus hindering the cobalt sintering rate. The initial selectivity to methane was slightly higher for 0.5%P-20%Co/SiO2 and 1.0%P-20%Co/SiO2 catalysts compared to the undoped catalyst, but at longer times differences were small. At higher loadings of P (3 wt.%), FT activity and selectivity were adversely and irreversibly affected.

AB - The effect of phosphorus addition on silica-supported cobalt catalyst was investigated for Fischer-Tropsch synthesis (FTS). As shown by STEM images and chemisorption, the addition of phosphorus to cobalt of up to 1 wt% increased the dispersion of cobalt. Further addition of phosphorus (e.g., 3 and 5 wt.%), as demonstrated by TPR, pulse reoxidation, and XANES, significantly hindered the reduction of cobalt oxides. The cobalt FTS catalysts containing 0.5 and 1.0 wt% P exhibited greater stability in comparison with undoped and 3.0 wt% P containing cobalt catalysts. Analysis of XANES spectra at the P and Co K-edges, along with DRIFTS results of H2-activated cobalt catalysts, suggest that cobalt particles interact with PO43− ions, indicating a role played by P in anchoring Co particles to the support, thus hindering the cobalt sintering rate. The initial selectivity to methane was slightly higher for 0.5%P-20%Co/SiO2 and 1.0%P-20%Co/SiO2 catalysts compared to the undoped catalyst, but at longer times differences were small. At higher loadings of P (3 wt.%), FT activity and selectivity were adversely and irreversibly affected.

KW - Cobalt

KW - EXAFS/XANES

KW - Fischer-Tropsch synthesis

KW - Phosphorus

KW - Promoter

KW - Silica

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DO - 10.1016/j.apcata.2016.05.024

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AN - SCOPUS:84975124877

SN - 0926-860X

VL - 523

SP - 146

EP - 158

JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

ER -

Fischer-Tropsch synthesis: Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts

Abstract

Bibliographical note

Funding

Keywords

ASJC Scopus subject areas

Access to Document

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