Effect of K, Mn and Cr on the Fischer–Tropsch Activity of Fe:Co/TiO2 Catalysts

Duvenhage, D.J.; Coville, Neil J.

doi:10.1007/s10562-005-7941-0

Cited by 23 publications

(13 citation statements)

References 32 publications

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“…Duvenhage et al. also reported that Mn led to lower reducibility of bimetallic Co/Fe catalysts and decreased their catalytic activity …”

Section: Introductionmentioning

confidence: 99%

“…[6] Duvenhage et al also reported that Mn led to lower reducibility of bimetallic Co/Fe catalysts and decreased their catalytic activity. [7] To solve the abovementioned problem, a full in situ characterization of the oxidation state and the local order around the active species of these materials at operational conditions is required. [8] X-ray absorption fine spectroscopy (XAFS) is mainly used to investigate the extended X-ray absorption fine structure (EXAFS) region, which reflects the local geometry of the compound, and the X-ray absorption nearedge structure (XANES) region, from which the chemical state of the metal atom can be obtained.…”

Section: Introductionmentioning

confidence: 99%

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Microstructure Evolution of a Co/MnO Catalyst for Fischer‐Tropsch Synthesis Revealed by In Situ XAFS Studies

Sun

Jin

et al. 2019

ChemCatChem

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Co−Mn catalysts have long been considered as a promising catalyst for Fischer‐Tropsch synthesis (FTS). However, the promotional role of Mn and its interaction with Co remain unclear and controversial. In situ characterization of the structural change of FTS catalysts is a powerful way to reveal the reaction mechanisms. Nevertheless, there are significant difficulties because of the harsh reaction conditions. Here, the microstructure evolution of Co/MnO catalysts during FTS is monitored by in situ X‐ray absorption fine structure (XAFS) spectroscopy under real FTS atmosphere up to 6 bar for the first time. Combined with in situ X‐ray diffraction (XRD), ex situ high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) and H2 chemisorption characterizations, we reveal that the metallic Co liberated from Mn1−xCoxO during FTS leads to activity enhancement. The presence of Mn improves the Co dispersion. However, an initial association of Mn with the Co phase hampers the cobalt reducibility. We also find that increasing the reaction pressure enhances the oxygen dissociation on the Mn surface, which leads to an increased number of exposed Co sites and consequent FTS activity improvement.

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“…Duvenhage et al. also reported that Mn led to lower reducibility of bimetallic Co/Fe catalysts and decreased their catalytic activity …”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Microstructure Evolution of a Co/MnO Catalyst for Fischer‐Tropsch Synthesis Revealed by In Situ XAFS Studies

Sun

Jin

et al. 2019

ChemCatChem

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“…Examples of the effectiveness of this oxide in increasing the C 5? -selectivity in the cobalt catalyzed FT reaction have been reported [11][12][13][14][15][16][17][18][19][20][21][22][23]. As an example, a study from Bezemer et al [21] showed an increase in C 5?…”

Section: Introductionmentioning

confidence: 99%

A Highly Active and Selective Manganese Oxide Promoted Cobalt-on-Silica Fischer–Tropsch Catalyst

et al. 2011

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A highly active and selective manganese oxidepromoted silica-supported cobalt catalyst for the FischerTropsch reaction is reported. Co/MnO/SiO 2 catalysts were prepared via impregnation of a cobalt nitrate and manganese nitrate precursor, followed by drying and calcination in an NO/He flow. The catalysts were studied with STEM-EELS, infrared spectroscopy measurements of adsorbed CO and Steady-State Isotopic Transient Kinetic Analysis experiments. Based on those experiments, a relation between C 5? -selectivity and surface-coverages of CH xintermediates on cobalt was found.

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“…In order to avoid residual alkali-metals, which have been reported to be detrimental to the FT activity of Co-catalysts [21,22], a co-precipitated 30 wt% Cu/30 wt% ZnO/Al 2 O 3 catalyst was prepared according to Ref. [23].…”

Section: Catalyst Preparationmentioning

confidence: 99%

Investigation of Mixtures of a Co-Based Catalyst and a Cu-Based Catalyst for the Fischer–Tropsch Synthesis with Bio-Syngas: The Importance of Indigenous Water

et al. 2011

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A series of different mechanical mixtures of a narrow-pore Co/c-Al 2 O 3 catalyst and a Cu-based WGScatalyst has been investigated in the low-temperature Fischer-Tropsch synthesis (483 K, 20 bar) with a model bio-syngas (H 2 /CO = 1.0) in a fixed-bed reactor. The higher the fraction of WGS-catalyst in the mixture, the lower is the Co-catalyst-time yield to hydrocarbons. This is ascribed to a strong positive kinetic effect of water on the Fischer-Tropsch rate of the Co-catalyst, showing the importance of the indigenously produced water, especially in fixed-bed reactors where the partial pressure of water is zero at the reactor inlet. A preliminary kinetic modeling suggests that the reaction order in P H 2 O is 0.3 for the Co/ c-Al 2 O 3 catalyst in the range of the studied reactor-average partial pressures of water (i.e., 0.04-1.2 bar).

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Effect of K, Mn and Cr on the Fischer–Tropsch Activity of Fe:Co/TiO2 Catalysts

Cited by 23 publications

References 32 publications

Microstructure Evolution of a Co/MnO Catalyst for Fischer‐Tropsch Synthesis Revealed by In Situ XAFS Studies

Microstructure Evolution of a Co/MnO Catalyst for Fischer‐Tropsch Synthesis Revealed by In Situ XAFS Studies

A Highly Active and Selective Manganese Oxide Promoted Cobalt-on-Silica Fischer–Tropsch Catalyst

Investigation of Mixtures of a Co-Based Catalyst and a Cu-Based Catalyst for the Fischer–Tropsch Synthesis with Bio-Syngas: The Importance of Indigenous Water

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