ε-Iron carbide as a low-temperature Fischer–Tropsch synthesis catalyst

Xu, Ke; Sun, Bo; Lin, Jun; Wen, Wen; Pei, Yan; Yan, Shaomin; Qiao, Minghua; Zhang, Xiao‐Xin; Zong, Baoning

doi:10.1038/ncomms6783

Cited by 230 publications

(168 citation statements)

References 56 publications

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“…This is indicated by the fact that the carbon from the active site was found to be incorporated into the final products . In the iron catalyzed Fischer‐Tropsch synthesis, iron carbide initiates the hydrocarbon chain growth, and a similar mechanism can be envisaged for MDA. Both DFT studies and experimental work suggest that CH 2 fragments can easily be formed by reaction of the carbon from the active site with gas phase hydrogen …”

Section: C−h Bond Activationmentioning

confidence: 99%

Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

et al. 2018

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To secure future supply of aromatics, methane is a commercially interesting alternative feedstock. Direct conversion of methane into aromatics combines the challenge of activating one of the strongest C−H bonds in all hydrocarbons with the selective aromatization over zeolites. To address these challenges, smart catalyst and process design are a must. And for that, understanding the most important factors leading to successful methane C−H bond activation and selective aromatization is needed. In this review, we summarize mechanistic insight that has been gained so far not only for this reaction, but also for other similar processes involving aromatization reactions over zeolites. With that, we highlight what can be learnt from similar processes. In addition, we provide an overview of characterization tools and strategies, which are useful to gain structural information about this particular metal‐zeolite system at reaction conditions. Here we also aim to inspire future characterization work, by giving an outlook on characterization strategies that have not yet been applied for the methane dehydroaromatization catalyst, but are promising for this system.

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Section: C−h Bond Activationmentioning

confidence: 99%

Progress in Developing a Structure‐Activity Relationship for the Direct Aromatization of Methane

et al. 2018

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“…According to the refinement results summarized in Table 3, the Fe metal content is reduced at the expense of Fe3C formation. Carburization of Fe is not unexpected as the reaction conditions for CO hydrogenation are very similar to Fischer-Tropsch synthesis (FTS) where Fe carbides are formed regardless of the initial phase of the catalyst [27,29,30]. Fe3C is generally accepted as a spectator or deactivation phase, and therefore, its contribution in the CO conversion and product distribution is not expected to be substantial [30,34,35].…”

Section: Catalyst Structure Under Reaction Conditions: In Situ Xrd Anmentioning

confidence: 99%

“…The analysis was completed by fitting the sample diffraction to an appropriate model where the lattice constants, scale factor, peak profile functions, and atomic potentials were varied to produce a simulated diffraction pattern nearly identical to the experimental XRD data. The models were chosen based upon knowledge of synthesis, reaction conditions, and phases previously identified in similar studies, that is, Rh metal, Fe metal, Fe-Rh alloys (FeRh and Fe0.7Rh0.3), FeO, Fe2O3, Fe3C, Fe2C, Fe5C2, anatase TiO2, and rutile TiO2 [20][21][22][23][24][25][26][27][28][29][30][31][32]. A complete refinement provides information about phase quantification, lattice constants, and particle size.…”

Section: In Situ Structure Determinationsmentioning

confidence: 99%

The effect of Fe–Rh alloying on CO hydrogenation to C2+ oxygenates

Palomino

Magee

Llorca³

et al. 2015

Journal of Catalysis

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a b s t r a c t A combination of reactivity and structural studies using X-ray diffraction (XRD), pair distribution function (PDF), and transmission electron microscopy (TEM) was used to identify the active phases of Fe-modified Rh/TiO2 catalysts for the synthesis of ethanol and other C2+ oxygenates from CO hydrogenation. XRD and TEM confirm the existence of Fe-Rh alloys for catalyst with 1-7 wt% Fe and '""2 wt% Rh. Rietveld refinements show that FeRh alloy content increases with Fe loading up to '""4 wt%, beyond which segregation to metallic Fe becomes favored over alloy formation. Catalysts that contain Fe metal after reduction exhibit some carburization as evidenced by the formation of small amounts of Fe3C during CO hydrogenation. Analysis of the total Fe content of the catalysts also suggests the presence of FeOx also increased under reaction conditions. Reactivity studies show that enhancement of ethanol selectivity with Fe loading is accompanied by a significant drop in CO conversion. Comparison of the XRD phase analyses with selectivity suggests that higher ethanol selectivity is correlated with the presence of Fe-Rh alloy phases. Overall, the interface between Fe and Rh serves to enhance the selectivity of ethanol, but suppresses the activity of the catalyst which is attributed to the blocking or modifying of Rh active sites.

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“…106,107 Carbon is a promising support for the FTS catalysts because of its relatively weak interaction with the active metals which is conducive to a high reduction degree of the metals. 106,107 Carbon is a promising support for the FTS catalysts because of its relatively weak interaction with the active metals which is conducive to a high reduction degree of the metals.…”

Section: Fischer-tropsch Synthesismentioning

confidence: 99%