Effect of reaction temperature and H2/CO ratio on deactivation behavior of precipitated iron Fischer-Tropsch synthesis catalyst

Li, Hu; Li, Weizhen; Zhuang, Zhuang; Liu, Fupeng; Li, Liangyi; Lv, Yijun; Men, Zhuowu; Liu, Zhen; Zhang, Yan

doi:10.1016/j.cattod.2022.04.025

Cited by 9 publications

(2 citation statements)

References 15 publications

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“…For one thing, the presence of Na was considered to improve the generation of the active phase of iron carbide which serves as the active site for olefin production in FTS according to the linear relationship between the amount of iron carbide and olefin yield. − For the other, the Na dopant is also regarded as an electronic promoter, which could modulate the catalytic behavior of Fe active sites. , In this case, the electron transfer from Na to Fe-based active sites is considered, which thus leads to a preferred reaction route toward olefin desorption from catalyst surfaces. Even though great progress has been achieved on the Fe-based FTS, the role of sodium has been still in suspense so far. , Owing to dynamic evolution and interplay of different active species, it is a challenge to independently examine the influence of these two factors on the intrinsic kinetics, as both of them might coexist and tangle with each other, especially under realistic redox conditions. − As such, it is quite urgent to disentangle the convolution between the apparent concentration and inherent properties change of active sites, further deciphering the intrinsic mechanism of the Na promoter effect on the enhanced F–T process.…”

Section: Introductionmentioning

confidence: 99%

Reversing the Selectivity of Alkanes and Alkenes in Iron-Based Fischer–Tropsch Synthesis: The Precise Control and Fundamental Role of Sodium Promotor

Wang,

Chen,

Shang

et al. 2024

ACS Catal.

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Alkali metals have been extensively used as an industrial promotor with a significant impact on the iron-based Fischer−Tropsch Synthesis (FTS), while their specific roles are still ambiguous due to the difficulty in discriminating the active species, especially in a dynamic evolution under reaction conditions. In this contribution, the dependent FTS performance on alkali metal content over iron-based catalysts by precise regulation of sodium (Na) doping was scrutinized. It is found that a trace addition of Na (0.5% mass fraction) dramatically switches the hydrocarbon selectivity from alkane to alkene, giving rise to total olefin selectivity from 27 to 76%. With the help of probe experiments and operando techniques, we demonstrate that the addition of Na can hardly affect the final state of iron carbide active species, but rather changes the formation rate of iron carbide, especially at the initial reaction stage. The presence of Na plays an exclusive role in regulating the electronic properties of iron carbide and adsorption behaviors of guest molecules, thus tailoring the reaction pathway by promoting the coupling of *CH 2 species while suppressing the excessive hydrogenation, which is deemed to be the intrinsic mechanism behind the high alkene selectivity. This work provides a clear-cut insight into the effect of alkali metal promotors for iron-based F−T catalytic systems as well as a theoretical basis for designing high-performance F−T catalysts.

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Section: Introductionmentioning

confidence: 99%

Reversing the Selectivity of Alkanes and Alkenes in Iron-Based Fischer–Tropsch Synthesis: The Precise Control and Fundamental Role of Sodium Promotor

Wang,

Chen,

Shang

et al. 2024

ACS Catal.

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“…F-T products are a combination of hydrocarbons and petrochemicals and, subsequently, many studies were carried out under F-T conditions in order to control the selectivity for the desired products. This control is achieved by selecting the suitable catalyst, reactor, and process conditions [1][2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of a New Perovskite Nanocatalyst in CO Hydrogenation

Sayadi Borazjani,

Pouranfard,

Razmjooei

2023

Chem Eng & Technol

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Operating conditions and selectivity of a new perovskite nanocatalyst were studied in Fischer‐Tropsch synthesis using a fixed‐bed microreactor. Selectivity equations were obtained using the experimental data collected from a hydrogenation process in a fixed‐bed microreactor. The operating conditions were obtained by defining the design‐of‐experiment scope based on response surface methodology, on 3 levels and in 15 tests. The optimum selectivity for alkenes relative to alkanes was obtained at 349.7 °C, 3.2 bar, and a H2/CO volumetric ratio of 1. Also, the optimum selectivity for alkenes relative to the overall selectivity for other products was attained at 250 °C, 2.3 bar, and a feed volumetric ratio of 2.

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Effective Prevention of Palladium Metal Particles Sintering by Histidine Stabilization on Silica Catalyst Support

Cahyanto,

Chen,

Lam

et al. 2024

Adv Funct Materials

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A robust method for enhancing the dispersion and stabilization of small metal nanoparticles in heterogeneous catalysts is developed. It involves in situ complexation of palladium(II) by histidine, in water, prior to impregnation in fumed silica. TEM images show that the histidine facilitates dispersion of the Pd(II) into finer nanoscale particles (≈2 nm) uniformly distributed on the support, rather than the large clusters (≈5 nm) seen in the absence of histidine. After hydrogen reduction, assessments using CO chemisorption and propylene hydrogenation indicate that the coordinated histidine might obscure the active sites on the Pd particles. However, as histidine decomposes between 220 and 300 °C in air, these materials are treated at 225 °C in air for 48 h. Afterwards the Pd(II) particles remain the same size, but after hydrogen reduction, there is a 2.4‐fold increase in CO gas adsorption, indicative of an expanded Pd surface area. Furthermore, superior catalyst stability (activity >200 h) is observed during propylene hydrogenation at 250 °C. This is consistent with histidine use having generated widely spaced, uniformly small, Pd nanoparticles on the silica support which is expected to help prevent agglomeration (sintering) during catalysis. This is a convenient low‐cost strategy for reducing metal content, preventing sintering and optimizing catalyst performance.

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Effect of reaction temperature and H2/CO ratio on deactivation behavior of precipitated iron Fischer-Tropsch synthesis catalyst

Cited by 9 publications

References 15 publications

Reversing the Selectivity of Alkanes and Alkenes in Iron-Based Fischer–Tropsch Synthesis: The Precise Control and Fundamental Role of Sodium Promotor

Reversing the Selectivity of Alkanes and Alkenes in Iron-Based Fischer–Tropsch Synthesis: The Precise Control and Fundamental Role of Sodium Promotor

Synthesis and Characterization of a New Perovskite Nanocatalyst in CO Hydrogenation

Effective Prevention of Palladium Metal Particles Sintering by Histidine Stabilization on Silica Catalyst Support

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