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

Research output: Contribution to journalArticlepeer-review

19 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 languageEnglish
Pages (from-to)146-158
Number of pages13
JournalApplied Catalysis A: General
Volume523
DOIs
StatePublished - 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.

Keywords

  • Cobalt
  • EXAFS/XANES
  • Fischer-Tropsch synthesis
  • Phosphorus
  • Promoter
  • Silica

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Fingerprint

Dive into the research topics of 'Fischer-Tropsch synthesis: Anchoring of cobalt particles in phosphorus modified cobalt/silica catalysts'. Together they form a unique fingerprint.

Cite this