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Sellmer, C.; Decker, Sébastien; Kruse, Norbert

doi:10.1023/a:1019004427482

Cited by 13 publications

(3 citation statements)

References 20 publications

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“…The first sharp hydrogen consumption peak, which occurs at 185−240 °C on the 15:85 Co/AC and at 205−240 °C on the three K-, Ce-, and Zr-promoted Co/AC catalysts, are attributed to reductive decomposition of Co(NO 3 ) 2 . This phenomenon was also observed between 220 and 300 °C on Co(NO 3 ) 2 /Al 2 O 3 and 130−300 °C on Co(NO 3 ) 2 /SiO 2 catalysts. , The second small hydrogen consumption peaks for the four catalysts occur between 240 and 285 °C, and are followed by the larger peaks between 285 and 370 °C. These procedures are assumed to represent the two-step reduction of decomposed Co(NO 3 ) 2 , Co 3 O 4 → CoO → Co, which is consistent with TPR results obtained on Al 2 O 3 - and SiO 2 -supported Co catalysts. ,,,, The fourth broad hydrogen consumption zone, which exists within the same temperature region of 400−620 °C in the four TPR profiles, was assigned to the interaction of H 2 with the surface active carbons or surface oxygen-containing groups on the AC surface …”

Section: Resultssupporting

confidence: 54%

“…This phenomenon was also observed between 220 and 300 °C on Co-(NO 3 ) 2 /Al 2 O 3 and 130-300 °C on Co(NO 3 ) 2 /SiO 2 catalysts. 47,48 The second small hydrogen consumption peaks for the four catalysts occur between 240 and 285 °C, and are followed by the larger peaks between 285 and 370 °C. These procedures are assumed to represent the two-step reduction of decomposed Co(NO 3 ) 2 , Co 3 O 4 f CoO f Co, which is consistent with TPR results obtained on Al 2 O 3 -and SiO 2 -supported Co catalysts.…”

Section: Effect Of K Ce and Zr Promotersmentioning

confidence: 97%

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Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Ding

Lin

2004

Ind. Eng. Chem. Res.

107

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The effects of Co loading and K, Ce, and Zr promoters on initial activities and selectivities of activated-carbon-supported cobalt (Co/AC) Fischer-Tropsch synthesis (FTS) catalysts, were studied under conditions of 240 °C, 2.4 MPa, 650 h -1 , and H 2 /CO ) 2:1 in a fixed-bed reactor. The reduction and metal dispersion properties of the catalysts were investigated through temperature-programmed reduction (TPR) and CO chemisorption. Detectable hydrocarbons up to C 20 were formed on the Co/AC catalysts. Co loading affected initial syngas conversion and CH 4 selectivity in the following order: 20%Co > 15%Co > 10%Co > 7%Co, whereas it had an opposite effect on content of C 12 -C 20 in the liquid organic product. K, Ce, and Zr promoters remarkably changed the initial catalytic performance of the Co/AC catalysts. Addition of K to the Co/AC catalyst significantly decreased the FTS activity and CH 4 selectivity, but increased the water gas shift (WGS) activity. Addition of Ce improved the Co/AC catalyst activity, accompanied by high CH 4 selectivity. Neither CO 2 nor CH 4 selectivity changed greatly on the Zr-promoted Co/AC catalyst even though the Zr promoter increased the FTS activity. The TPR and CO adsorption studies showed that K, Ce, and Zr promoters improved Co dispersion and interaction between Co oxide and the AC surface, which might be the reasons for the subsequent catalyst performance, especially for the Ce-and Zr-promoted catalysts. The TPR study also showed that the reduction steps of the reductively decomposed Co/AC catalysts by pure H 2 are Co 3 O 4 f CoO f Co.

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Section: Resultssupporting

confidence: 54%

Section: Effect Of K Ce and Zr Promotersmentioning

confidence: 97%

Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Ding

Lin

2004

Ind. Eng. Chem. Res.

107

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“…The FT synthesis still continues to attract considerable research attention due to the efficient utilization of syngas derived from abundant resources such as natural gas, coal, and/or biomass. − However, the FT products composed mainly of normal alkanes and alkenes with a wide carbon chain length are nonselective to any specific hydrocarbons due to the limitation of Anderson−Schulz−Flory (ASF) polymerization kinetics. Therefore, the key for improving the efficiency of FT synthesis is to break the ASF law such that desired products, e.g., high-quality gasoline or diesel, can be selectively produced.…”

Section: Introductionmentioning

confidence: 99%

Insights into a Multifunctional Hybrid Catalyst Composed of Co/SiO₂ and Pd/Beta for Isoparaffin Production from Syngas

Liu

Asami

et al. 2005

Ind. Eng. Chem. Res.

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The direct production of gasoline-range isoparaffins from synthesis gas (CO + H 2 , syngas) via the Fischer-Tropsch (FT) route was investigated over a hybrid catalyst composed of Co/SiO 2 and Pd/β under the conditions of P ) 1.0 MPa, W/F ) 7.9 g‚h‚mol -1 and reaction temperatures of 503-513 K. Results indicate that the contact state between the Co/SiO 2 and the Pd/β particles in the hybrid catalyst (powdery mixture and granular mixture) had a clear effect on both the activity toward CO hydrogenation and the product distribution. Interestingly, the granular hybrid catalyst showed much higher performance in the case of isoparaffin selectivity than the powdery hybrid catalyst at the initial stage of the reaction. Furthermore, irrespective of the reaction conditions applied, the powdery hybrid catalyst gave apparently lower CO conversion and obviously higher CH 4 selectivity than the granular hybrid catalyst. Irrespective of the catalyst used, the total selectivity of isoparaffins (I/C 4 +) noticeably decreased with TOS due to the increase of selectivity of normal paraffins, the decrease of selectivity of isoparaffins, and less cracking of long-chain FT hydrocarbons. In the case of the powdery hybrid catalyst, a synergistic effect of the FT reaction over Co/SiO 2 and the hydroconversion reaction over Pd/β was suggested from the reaction results. A mechanistic model based on the migration of hydrogen species at the interfaces of the different particles was developed, and the reaction results were extensively discussed based on the proposed model.

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Low Energy Ion Scattering and Secondary Ion Mass Spectrometry

Kruse

Chenakin

2012

Characterization of Solid Materials and Heterogeneous Catalysts

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Cited by 13 publications

References 20 publications

Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Insights into a Multifunctional Hybrid Catalyst Composed of Co/SiO₂ and Pd/Beta for Isoparaffin Production from Syngas

Low Energy Ion Scattering and Secondary Ion Mass Spectrometry

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Untitled

Cited by 13 publications

References 20 publications

Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Fischer−Tropsch Synthesis over Activated-Carbon-Supported Cobalt Catalysts: Effect of Co Loading and Promoters on Catalyst Performance

Insights into a Multifunctional Hybrid Catalyst Composed of Co/SiO2 and Pd/Beta for Isoparaffin Production from Syngas

Low Energy Ion Scattering and Secondary Ion Mass Spectrometry

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Product

Resources

About

Insights into a Multifunctional Hybrid Catalyst Composed of Co/SiO₂ and Pd/Beta for Isoparaffin Production from Syngas