CO dissociation on Ru and Co surfaces: The initial step in the Fischer–Tropsch synthesis

Shetty, SG Sharankumar; Santen, Rutger A. van

doi:10.1016/j.cattod.2011.04.006

Cited by 125 publications

(125 citation statements)

References 36 publications

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“…However, it is demonstrated recently by van Santen and coworkers that the hydrogen-assisted pathway is unfavorable for the Co (10-10) surface since the overall barrier of the hydrogen-assisted pathway via HCO is 0.38 eV higher than the direct dissociation and COH is thermodynamically unstable [28]. Based on this, they proposed that the carbide mechanism is more favorable [27]. Recently, Li and coworkers employed firstprinciples kinetic studies to identify the structure-sensitivity of the CO dissociation in FTS [113].…”

Section: Co Activationmentioning

confidence: 99%

“…More importantly, it can distinguish between those possibilities that were left open, such as various reaction pathways. Since the mechanism of FTS is inconclusive and controversial, more and more DFT calculations have been devoted to tackle these issues [18,19], especially for the mechanism of CO activation [27][28][29][30][31], methane formation [32][33][34][35], and chain growth [36][37][38]. Despite the successful implementations of DFT in catalysis process, it still holds some drawbacks such as failure in the calculation of weak interactions (such as Van der Waals interaction) [25].…”

Section: Introductionmentioning

confidence: 99%

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Recent Progresses in Understanding of Co-Based Fischer–Tropsch Catalysis by Means of Transient Kinetic Studies and Theoretical Analysis

Yang

Chen

et al. 2014

Catal Lett

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During the last years it has been an increasing focus on fundamental studies of the Fischer-Tropsch synthesis (FTS). Steady-state isotopic transient kinetic analysis and first principles investigation have proven to be important methods in studying the reaction mechanism of FTS. The present contribution deals with recent progresses in understanding of the F-T mechanism on Co catalysts based on combined DFT calculations, in situ characterization, steady-state isotopic transient kinetic analysis and microkinetics. A brief outlook into future perspectives of the FTS for converting synthesis gas from different carbon sources to fuels and chemicals is also provided.

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Section: Co Activationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Recent Progresses in Understanding of Co-Based Fischer–Tropsch Catalysis by Means of Transient Kinetic Studies and Theoretical Analysis

Yang

Chen

et al. 2014

Catal Lett

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“…3 Theoretical and experimental works to date suggest that a hydrogen-assisted pathway should be more favorable on close-packed surfaces, whereas the carbide mechanism is preferred on stepped and corrugated surfaces. 1,[4][5][6][7][8] Theoretical studies have provided support for dissociation via H x CO intermediates on Ru(0001) (Ref. 5) and Co(0001).…”

Section: Introductionmentioning

confidence: 99%

“…1,2 Two basic mechanisms have been proposed for the dissociation of CO on metal surfaces: direct dissociation of CO (carbide formation) and dissociation via a hydrogenated intermediate. In the latter case, there is increasing interest in the possible role of formyl as an intermediate species.…”

Section: Introductionmentioning

confidence: 99%

Evidence of stable high-temperature Dx-CO intermediates on the Ru(0001) surface

Ueta

Groot

Juurlink

et al. 2012

The Journal of Chemical Physics

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We demonstrate the formation of complexes involving attractive interactions between D and CO on Ru(0001) that are stable at significantly higher temperatures than have previously been reported for such intermediate species on this surface. These complexes are evident by the appearance of new desorption features upon heating of the sample. They decompose in stages as the sample temperature is increased, with the most stable component desorbing at >500 K. The D:CO ratio remaining on the surface during the final stages of desorption tends towards 1:1. The new features are populated during normally incident molecular beam dosing of D 2 on to CO pre-covered Ru(0001) surfaces (180 K) when the CO coverage exceeds 50% of the saturation value. The amount of complex formed decreases somewhat with increasing CO pre-coverage. It is almost absent in the case of dosing on to the fully saturated surface. The results are interpreted in terms of both local and long-range rearrangements of the overlayer that give rise to the observed CO coverage dependence and limit the amount of complex that can be formed.

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“…Carballo et al 36 investigated the size effect of Ru particles supported on γ-Al 2 O 3 and found that the FT synthesis with Ru/γ-Al 2 O 3 catalysts is a strongly structure-sensitive reaction when the size of Ru particles was smaller than 10 nm. Theoretical understanding of the origin of the effect of metal particle size on reaction rates of a given reaction has been tackled by Van Santen et al 23,37 They stated that the CO activation in the FT reaction needs a reaction center with a particular configuration of several metal atoms and step-edge sites, which geometrically may not be present below a particle size of 2 nm. As the support material may mask the metal particle size effects, research focused on intrinsic ruthenium particle size effects may be advantageously performed using an inert support material, such as graphitic carbon.…”

Section: Introductionmentioning

confidence: 99%

Ruthenium particle size and cesium promotion effects in Fischer–Tropsch synthesis over high-surface-area graphite supported catalysts

Eslava

Gascón

Kapteijn

et al. 2017

Catal. Sci. Technol.

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. Ruthenium particle size and cesium promotion effects in Fischer-Tropsch synthesis over high-surface-area graphite supported catalysts. Catalysis Science & Technology, 7(5), 1235-1244. DOI: 10.1039/c6cy02535h Important noteTo cite this publication, please use the final published version (if applicable). Please check the document version above. CopyrightOther than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policyPlease contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim. The effect of ruthenium particle size on Fischer-Tropsch synthesis (FTS) has been studied at 513 K, H2/CO = 2 and 15 bar. Supported Ru catalysts with particle sizes ranging from 1.7 to 12 nm were prepared by using different Ru loadings and two different high surface area graphite (HSAG) supports to minimize the metal-support interaction. In addition, the effect of promotion with Cs is also evaluated. Microcalorimetric characterization during CO adsorption and XPS reveal a clear interaction between Ru and Cs. The FTS with Ru-based catalysts is, independent of the presence of promoter, highly structure-sensitive when the Ru particle size is under 7 nm. In this range the turnover frequency (TOF) for CO conversion increases with particle size, reaching a near constant value for Ru particles larger than 7 nm. Cs promoted catalysts display lower TOF values than the corresponding unpromoted samples. This somewhat reduced activity is attributed to the stronger CO adsorption on Cs promoted catalysts, as demonstrated by CO adsorption microcalorimetry. Product selectivity depends also on Ru particle size. Selectivity to C5+ hydrocarbons increases with increasing Ru particle size. For Cs-promoted catalysts, the olefin to paraffin ratio in the C2-C4 hydrocarbons range is independent of the Ru particle size, whereas it decreases for the unpromoted catalysts, showing the prevailing influence of the promoter.

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CO dissociation on Ru and Co surfaces: The initial step in the Fischer–Tropsch synthesis

Cited by 125 publications

References 36 publications

Recent Progresses in Understanding of Co-Based Fischer–Tropsch Catalysis by Means of Transient Kinetic Studies and Theoretical Analysis

Recent Progresses in Understanding of Co-Based Fischer–Tropsch Catalysis by Means of Transient Kinetic Studies and Theoretical Analysis

Evidence of stable high-temperature Dx-CO intermediates on the Ru(0001) surface

Ruthenium particle size and cesium promotion effects in Fischer–Tropsch synthesis over high-surface-area graphite supported catalysts

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