Effect of support surface treatment on the synthesis, structure, and performance of Co/CNT Fischer-Tropsch catalysts

Thomas O. Eschemann; Wouter S. Lamme; Rene L. Manchester; Tanja E. Parmentier; Andrea Cognigni; Magnus Ronning; Krijn P. de Jong

doi:10.1016/j.jcat.2014.12.010

Effect of support surface treatment on the synthesis, structure, and performance of Co/CNT Fischer-Tropsch catalysts

Thomas O. Eschemann, Wouter S. Lamme, Rene L. Manchester, Tanja E. Parmentier, Andrea Cognigni, Magnus Ronning^*, Krijn P. de Jong

^*Corresponding author for this work

Sub Inorganic Chemistry and Catalysis

Norwegian University of Science and Technology

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

Abstract

We report the preparation of supported cobalt catalysts (9 wt% Co) on untreated (CNT) and surface-oxidized (CNT-ox) carbon nanotube materials by incipient wetness impregnation with solutions of cobalt nitrate in water, ethanol, or 1-propanol. The results show that by a judicious selection of solvent and drying method, similar cobalt oxide particle sizes in the range of 4-5 nm on CNT and CNT-ox materials were obtained for the fresh catalysts. Cobalt particles supported on unfunctionalized CNT showed higher initial activities and C5+-selectivities than catalysts on functionalized CNT; however, the former catalysts were more prone to cobalt particle growth due to the lack of anchoring sites. The activities and cobalt particle sizes of catalysts after 60 h on stream revealed for particles larger than 6 nm a turnover frequencies (TOF) of 0.07 s(-1) for Co/CNT and 0.03 s(-1) for Co/CNT-ox. In situ XAS/XRPD studies showed a similar degree of reduction for the catalysts on untreated and oxidized CNT and the formation of hcp cobalt metal on untreated CNT which rationalizes the higher activity and TOF of the Co/CNT catalysts. (C) 2014 Elsevier Inc. All rights reserved.

Original language	English
Pages (from-to)	130-138
Number of pages	9
Journal	Journal of Catalysis
Volume	328
DOIs	https://doi.org/10.1016/j.jcat.2014.12.010
Publication status	Published - Aug 2015

Funding

We gratefully acknowledge Shell Global Solutions for financial support. We also thank Jesper Sattler for carrying out Raman spectroscopy, Daniel Stellwagen for help with interpreting Raman spectra, and Rien van Zwienen for technical assistance on high-pressure catalytic testing. The Research Council of Norway is acknowledged for financial support through the SYNKNOYT program, and the personnel of the Swiss-Norwegian Beamlines (SNBL) at ESRF are highly acknowledged for experimental assistance.

Keywords

Fischer-Tropsch
Carbon nanotubes (CNT)
Cobalt
Impregnation
Solvent effects
Surface functionalization
Gas-phase oxidation
COBALT PARTICLE-SIZE
HIGH-RESOLUTION XPS
CARBON NANOTUBES
HYDROCARBON SELECTIVITY
PRODUCT DISTRIBUTION
NOBLE-METALS
CO CATALYST
FIXED-BED
NANOFIBERS
OXYGEN

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10.1016/j.jcat.2014.12.010

1-s2.0-S0021951714003455-mainFinal published version, 1.33 MBLicence: Taverne

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@article{5d1788ac58584ad092a959aad432abbf,

title = "Effect of support surface treatment on the synthesis, structure, and performance of Co/CNT Fischer-Tropsch catalysts",

abstract = "We report the preparation of supported cobalt catalysts (9 wt% Co) on untreated (CNT) and surface-oxidized (CNT-ox) carbon nanotube materials by incipient wetness impregnation with solutions of cobalt nitrate in water, ethanol, or 1-propanol. The results show that by a judicious selection of solvent and drying method, similar cobalt oxide particle sizes in the range of 4-5 nm on CNT and CNT-ox materials were obtained for the fresh catalysts. Cobalt particles supported on unfunctionalized CNT showed higher initial activities and C5+-selectivities than catalysts on functionalized CNT; however, the former catalysts were more prone to cobalt particle growth due to the lack of anchoring sites. The activities and cobalt particle sizes of catalysts after 60 h on stream revealed for particles larger than 6 nm a turnover frequencies (TOF) of 0.07 s(-1) for Co/CNT and 0.03 s(-1) for Co/CNT-ox. In situ XAS/XRPD studies showed a similar degree of reduction for the catalysts on untreated and oxidized CNT and the formation of hcp cobalt metal on untreated CNT which rationalizes the higher activity and TOF of the Co/CNT catalysts. (C) 2014 Elsevier Inc. All rights reserved.",

keywords = "Fischer-Tropsch, Carbon nanotubes (CNT), Cobalt, Impregnation, Solvent effects, Surface functionalization, Gas-phase oxidation, COBALT PARTICLE-SIZE, HIGH-RESOLUTION XPS, CARBON NANOTUBES, HYDROCARBON SELECTIVITY, PRODUCT DISTRIBUTION, NOBLE-METALS, CO CATALYST, FIXED-BED, NANOFIBERS, OXYGEN",

author = "Eschemann, {Thomas O.} and Lamme, {Wouter S.} and Manchester, {Rene L.} and Parmentier, {Tanja E.} and Andrea Cognigni and Magnus Ronning and {de Jong}, {Krijn P.}",

year = "2015",

month = aug,

doi = "10.1016/j.jcat.2014.12.010",

language = "English",

volume = "328",

pages = "130--138",

journal = "Journal of Catalysis",

issn = "0021-9517",

publisher = "Academic Press Inc.",

}

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T1 - Effect of support surface treatment on the synthesis, structure, and performance of Co/CNT Fischer-Tropsch catalysts

AU - Eschemann, Thomas O.

AU - Lamme, Wouter S.

AU - Manchester, Rene L.

AU - Parmentier, Tanja E.

AU - Cognigni, Andrea

AU - Ronning, Magnus

AU - de Jong, Krijn P.

PY - 2015/8

Y1 - 2015/8

N2 - We report the preparation of supported cobalt catalysts (9 wt% Co) on untreated (CNT) and surface-oxidized (CNT-ox) carbon nanotube materials by incipient wetness impregnation with solutions of cobalt nitrate in water, ethanol, or 1-propanol. The results show that by a judicious selection of solvent and drying method, similar cobalt oxide particle sizes in the range of 4-5 nm on CNT and CNT-ox materials were obtained for the fresh catalysts. Cobalt particles supported on unfunctionalized CNT showed higher initial activities and C5+-selectivities than catalysts on functionalized CNT; however, the former catalysts were more prone to cobalt particle growth due to the lack of anchoring sites. The activities and cobalt particle sizes of catalysts after 60 h on stream revealed for particles larger than 6 nm a turnover frequencies (TOF) of 0.07 s(-1) for Co/CNT and 0.03 s(-1) for Co/CNT-ox. In situ XAS/XRPD studies showed a similar degree of reduction for the catalysts on untreated and oxidized CNT and the formation of hcp cobalt metal on untreated CNT which rationalizes the higher activity and TOF of the Co/CNT catalysts. (C) 2014 Elsevier Inc. All rights reserved.

AB - We report the preparation of supported cobalt catalysts (9 wt% Co) on untreated (CNT) and surface-oxidized (CNT-ox) carbon nanotube materials by incipient wetness impregnation with solutions of cobalt nitrate in water, ethanol, or 1-propanol. The results show that by a judicious selection of solvent and drying method, similar cobalt oxide particle sizes in the range of 4-5 nm on CNT and CNT-ox materials were obtained for the fresh catalysts. Cobalt particles supported on unfunctionalized CNT showed higher initial activities and C5+-selectivities than catalysts on functionalized CNT; however, the former catalysts were more prone to cobalt particle growth due to the lack of anchoring sites. The activities and cobalt particle sizes of catalysts after 60 h on stream revealed for particles larger than 6 nm a turnover frequencies (TOF) of 0.07 s(-1) for Co/CNT and 0.03 s(-1) for Co/CNT-ox. In situ XAS/XRPD studies showed a similar degree of reduction for the catalysts on untreated and oxidized CNT and the formation of hcp cobalt metal on untreated CNT which rationalizes the higher activity and TOF of the Co/CNT catalysts. (C) 2014 Elsevier Inc. All rights reserved.

KW - Fischer-Tropsch

KW - Carbon nanotubes (CNT)

KW - Cobalt

KW - Impregnation

KW - Solvent effects

KW - Surface functionalization

KW - Gas-phase oxidation

KW - COBALT PARTICLE-SIZE

KW - HIGH-RESOLUTION XPS

KW - CARBON NANOTUBES

KW - HYDROCARBON SELECTIVITY

KW - PRODUCT DISTRIBUTION

KW - NOBLE-METALS

KW - CO CATALYST

KW - FIXED-BED

KW - NANOFIBERS

KW - OXYGEN

U2 - 10.1016/j.jcat.2014.12.010

DO - 10.1016/j.jcat.2014.12.010

M3 - Article

SN - 0021-9517

VL - 328

SP - 130

EP - 138

JO - Journal of Catalysis

JF - Journal of Catalysis

ER -

Effect of support surface treatment on the synthesis, structure, and performance of Co/CNT Fischer-Tropsch catalysts

Abstract

Funding

Keywords

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