Comparison of Synthesis Techniques for Supported Iron Nanocatalysts

Tasfy, Sara Faiz Hanna; Zabidi, Noor Asmawati Mohd; Subbarao, Duvvuri

doi:10.3923/jas.2011.1150.1156

Cited by 7 publications

(5 citation statements)

References 13 publications

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“…The synthesis method affects the morphology, catalyst particle size and surface area of the final catalyst to a large extent. Tasfy et al [84] indicated that, compared to precipitation method, the average particle size of the Fe particles supported on SiO 2 was smaller when the catalyst was prepared by the impregnation. In another work, Sarkari et al [85] indicated the effects of the preparation method on the catalytic activity of bimetallic Fe-Ni catalyst supported on alumina.…”

Section: Catalyst Preparationmentioning

confidence: 99%

Kinetics and Selectivity Study of Fischer–Tropsch Synthesis to C5+ Hydrocarbons: A Review

2021

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Fischer-Tropsch synthesis (FTS) is considered as one of the non-oil-based alternatives for liquid fuel production. This gas-to-liquid (GTL) technology converts syngas to a wide range of hydrocarbons using metal (Fe and Co) unsupported and supported catalysts. Effective design of the catalyst plays a significant role in enhancing syngas conversion, selectivity towards C5+ hydrocarbons, and decreasing selectivity towards methane. This work presents a review on catalyst design and the most employed support materials in FTS to synthesize heavier hydrocarbons. Furthermore, in this report, the recent achievements on mechanisms of this reaction will be discussed. Catalyst deactivation is one of the most important challenges during FTS, which will be covered in this work. The selectivity of FTS can be tuned by operational conditions, nature of the catalyst, support, and reactor configuration. The effects of all these parameters will be analyzed within this report. Moreover, zeolites can be employed as a support material of an FTS-based catalyst to direct synthesis of liquid fuels, and the specific character of zeolites will be elaborated further. Furthermore, this paper also includes a review of some of the most employed characterization techniques for Fe- and Co-based FTS catalysts. Kinetic study plays an important role in optimization and simulation of this industrial process. In this review, the recent developed reaction rate models are critically discussed.

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Section: Catalyst Preparationmentioning

confidence: 99%

Kinetics and Selectivity Study of Fischer–Tropsch Synthesis to C5+ Hydrocarbons: A Review

2021

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“…Given the strongly reducing conditions for catalysis, the resultant dark color during catalysis, and our kinetic observations, we asked the question, ‘Could the active species be a heterogeneous catalyst?’. The Fischer–Tropsch process , and the Haber–Bosch synthesis are the two most common examples of the use of iron in heterogeneous catalysis; however a limited number of other examples do exist as olefin hydrogenation catalysts. − Iron nanoparticles are also catalysts for the formation of carbon nanotubes, − the reduction of peroxides and CO 2 , and the hydrolytic dehydrogenation of ammonia boranes . Iron oxides have been used as nanoparticle supports for heterogeneous catalysis with other metals as the active sites, − but the use of zerovalent iron as an active site for asymmetric catalysis has not been reported.…”

Section: Introductionmentioning

confidence: 99%

Iron Nanoparticles Catalyzing the Asymmetric Transfer Hydrogenation of Ketones

et al. 2012

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Investigation into the mechanism of transfer hydrogenation using trans-[Fe(NCMe)CO(PPh(2)C(6)H(4)CH═NCHR-)(2)][BF(4)](2), where R = H (1) or R = Ph (2) (from R,R-dpen), has led to strong evidence that the active species in catalysis are iron(0) nanoparticles (Fe NPs) functionalized with achiral (with 1) and chiral (with 2) PNNP-type tetradentate ligands. Support for this proposition is given in terms of in operando techniques such as a kinetic investigation of the induction period during catalysis as well as poisoning experiments using substoichiometric amounts of various poisoning agents. Further support for the presence of Fe(0) NPs includes STEM microscopy imaging with EDX analysis, XPS analysis, and SQUID magnetometry analysis of catalytic solutions. Further evidence of Fe NPs acting as the active catalyst is given in terms of a polymer-supported substrate experiment whereby the NPs are too large to permeate the pores of a functionalized polymer. Final support is given in terms of a combined poisoning/STEM/EDX experiment whereby the poisoning agent is shown to be bound to the Fe NPs. This paper provides evidence of a rare example of asymmetric catalysis with nonprecious metal, zerovalent nanoparticles.

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“…This first H 2 consumption is typically related to the reduction of dispersed Fe 3+ to form Fe 2+ species. At temperatures centered near 700 °C more hydrogen is consumed which is typically related to the reduction of Fe 2+ to Fe o . Based on this TPR result, three samples were prepared by reduction with H 2 at 500, 800, and 900 °C for 2 h. Reduction at 500 °C turned the sample from brown to grey.…”

Section: Resultsmentioning

confidence: 99%

“…At temperatures centered near 700 ∘ C more hydrogen is consumed which is typically related to the reduction of Fe 2+ to Fe o . 40 Based on this TPR result, three samples were prepared by reduction with H 2 at 500, 800, and 900 ∘ C for 2 h. Reduction at 500 ∘ C turned the sample from brown to grey. The absence of apparent magnetism of the product obtained after reduction at 500 ∘ C suggests that most of the Fe 2+ was dispersed in the silica matrix or combined as Fe 2 SiO 4 .…”

Section: Resultsmentioning

confidence: 99%