Fischer-Tropsch synthesis on cobalt and ruthenium. Metal dispersion and support effects on reaction rate and selectivity

Iglesia, Enrique; Soled, S.; Fiato, Rocco A.

doi:10.1016/0021-9517(92)90150-g

Cited by 511 publications

(125 citation statements)

References 34 publications

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“…In addition, the catalytic activity normalized to the level of dispersion was almost constant among all the Ru-modified catalysts. This result indicates that the site-time yields over the Co catalysts were independent of the metal dispersion, and that the nature of the active sites on the catalysts is likely unchanged, which is also consistent with the findings of Iglesia et al [6]. Our previous work [17] suggested that, during the coimpregnation catalyst preparation process, the interaction between Co and Mn species enhances Co dispersion and therefore FT synthesis activity.…”

Section: Effect Of Noble Metal Addition and Impregnation Ordersupporting

confidence: 79%

“…Co-based catalysts are the most widely applied for this reaction since they exhibit higher activity and selectivity and thus are more economical [3,4]. It is generally accepted that the activity of Co catalysts for FT synthesis depends OPEN ACCESS on the presence of surface-exposed Co metal atoms [5,6], and therefore Co species should be both highly dispersed and reduced on the catalyst surface. For this reason, Co is generally deposited on high surface area supports such as SiO2 [7][8][9][10][11], Al2O3 [12,13] and TiO2 [14,15], in order to increase the quantity of active Co metal species.…”

Section: Introductionmentioning

confidence: 99%

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Ruthenium Modification on Mn and Zr-Modified Co/SiO2 Catalysts for Slurry-Phase Fischer-Tropsch Synthesis

Miyazawa¹,

Hanaoka²,

Shimura³

et al. 2015

Catalysts

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Abstract:The addition of Ru to Mn and Zr-modified Co/SiO2 catalysts, while applying different preparation orders and loading amounts, was investigated as a means of enhancing the Fischer-Tropsch synthesis reaction. The coimpregnation of Zr/SiO2 with Co, Mn and Ru gave the most attractive catalytic properties. This can be attributed to the higher dispersion of Co metal resulting from the coimpregnation of Co and Mn as well as enhanced reducibility due to the presence of Ru. The addition of a moderate amount of Ru together with the appropriate order of addition affected both the Co reducibility and the catalytic activity, primarily because of increased reducibility. The addition of even 0.1 wt.% Ru resulted in an obvious enhancement of Fischer-Tropsch synthesis activity.

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Section: Effect Of Noble Metal Addition and Impregnation Ordersupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Ruthenium Modification on Mn and Zr-Modified Co/SiO2 Catalysts for Slurry-Phase Fischer-Tropsch Synthesis

Miyazawa¹,

Hanaoka²,

Shimura³

et al. 2015

Catalysts

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“…Regarding active metal, the production of commercial fuels from syngas is mostly based on supported Co catalysts. Iglesia et al established that neither the nature of the support nor the dispersion of Co particles influenced turnover frequency (TOF) of these catalysts, but it was proportional to the concentration of active sites on the surface [4][5][6]. Johnson et al [7] agree with the fact that TOF was not affected by dispersion, although CO conversion seemed to be strongly dependent on Co reducibility.…”

Section: Introductionsupporting

confidence: 63%

Influence of Cobalt Precursor on Efficient Production of Commercial Fuels over FTS Co/SiC Catalyst

et al. 2016

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β-SiC-supported cobalt catalysts have been prepared from nitrate, acetate, chloride and citrate salts to study the dependence of Fischer-Tropsch synthesis (FTS) on the type of precursor. Com/SiC catalysts were synthetized by vacuum-assisted impregnation while N 2 adsorption/desorption, XRD, TEM, TPR, O 2 pulses and acid/base titrations were used as characterization techniques. FTS catalytic performance was carried out at 220˝C and 250˝C while keeping constant the pressure (20 bar), space velocity (6000 Ncm 3 /g¨h) and syngas composition (H 2 /CO:2). The nature of cobalt precursor was found to influence basic behavior, extent of reduction and metallic particle size. For β-SiC-supported catalysts, the use of cobalt nitrate resulted in big Co crystallites, an enhanced degree of reduction and higher basicity compared to acetate, chloride and citrate-based catalysts. Consequently, cobalt nitrate provided a better activity and selectivity to C 5 + (less than 10% methane was formed), which was centered in kerosene-diesel fraction (α = 0.90).On the contrary, catalyst from cobalt citrate, characterized by the highest viscosity and acidity values, presented a highly dispersed distribution of Co nanoparticles leading to a lower reducibility. Therefore, a lower FTS activity was obtained and chain growth probability was shortened as observed from methane and gasoline-kerosene (α = 0.76) production when using cobalt citrate.

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“…Numerous studies have been devoted to gain an understanding of the effect of the support and Co structure on the catalytic performance. [2][3][4][5][6][7][8][9][10][11][12][13][14][15] The precise influence of the catalyst variables remains unclear.T he effect of the Co particles ize on the activity and selectivity is still under debate.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the Influence of the Microstructure of Alumina‐Supported Cobalt Catalysts on their Activity and Selectivity in Fischer–Tropsch Synthesis by using Steady‐State and Transient Kinetics

et al. 2017

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Five alumina‐supported Co catalysts with different particle sizes and structures were synthesized. The catalysts showed different activities during long‐term Fischer–Tropsch experiments. Steady‐state isotopic transient kinetic analysis (SSITKA) 12CO/H2→13CO/H2 experiments were performed during these long‐term runs. The number of active sites for CO adsorption and activation was estimated through the summation of all surface intermediates derived from the SSITKA results. Rather than comparing turnover frequencies, a kinetic analysis was performed. A simple kinetic rate equation based on the in situ number of active sites described the steady‐state CO conversion over the five catalysts adequately. Thus the difference in the catalytic performance could not be attributed to a difference in particle size, phase orientation (face‐centered cubic or hexagonal close packed), or Pt‐promotion effect but instead was only because of the number of reduced Co atoms exposed during the reaction. Similarly, the selectivity depended on the CO conversion level and temperature and not on the catalyst structure.

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Fischer-Tropsch synthesis on cobalt and ruthenium. Metal dispersion and support effects on reaction rate and selectivity

Cited by 511 publications

References 34 publications

Ruthenium Modification on Mn and Zr-Modified Co/SiO2 Catalysts for Slurry-Phase Fischer-Tropsch Synthesis

Ruthenium Modification on Mn and Zr-Modified Co/SiO2 Catalysts for Slurry-Phase Fischer-Tropsch Synthesis

Influence of Cobalt Precursor on Efficient Production of Commercial Fuels over FTS Co/SiC Catalyst

Measurement of the Influence of the Microstructure of Alumina‐Supported Cobalt Catalysts on their Activity and Selectivity in Fischer–Tropsch Synthesis by using Steady‐State and Transient Kinetics

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