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Petr A. Chernavskii - One of the best experts on this subject based on the ideXlab platform.

  • Study the hematite reduction kinetics by the Magnetic Method
    Thermochimica Acta, 2020
    Co-Authors: Petr A. Chernavskii, Galina V. Pankina, Sergey V. Maksimov, N.v. Kim, Alla A. Novakova
    Abstract:

    Abstract This study is devoted to the reduction of Fe2O3 supported on silica gel in H2 in the temperature range of 290–600 °C. A continuous magnetization measurement Method was used to obtain the temperature programmed reduction (TPR) profile. The influence of the external Magnetic field on the dynamics of the process is investigated. It was shown that the TPR profile depends both on the magnitude of the applied field and on the particle size of hematite.

  • Formation of Co-Ru/MgO/Al2O3 catalysts for the Fischer-Tropsch synthesis: A Magnetic Method for the estimation of cobalt particle size
    Kinetics and Catalysis, 2007
    Co-Authors: Galina V. Pankina, Petr A. Chernavskii, A. Yu. Krylova, V. V. Lunin
    Abstract:

    The physicochemical properties of Co-supported catalysts were studied, and the particle size of Co in Co/MgO/Al2O3 and Co-0.2% Ru/MgO/Al2O3 catalysts for the Fischer-Tropsch synthesis (FTS) was estimated using a Magnetic Method. It was found that a considerable fraction of superparaMagnetic Co particles, which increase selectivity for C5+ hydrocarbons and decrease the yield of methane in the FTS, was present in a ruthenium-containing catalyst along with single-domain ferroMagnetic particles. In this case, the catalyst activity increased by a factor of 10.

  • Characterization of the Genesis of Cobalt Metal Particles in Silica-Supported Fischer-Tropsch Catalysts using Foner Magnetic Method
    Applied Catalysis A : General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    The genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method.

  • In situ characterization of the genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts using Foner Magnetic Method
    Applied Catalysis A: General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    International audienceThe genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method

Elodie Quinet - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the Genesis of Cobalt Metal Particles in Silica-Supported Fischer-Tropsch Catalysts using Foner Magnetic Method
    Applied Catalysis A : General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    The genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method.

  • In situ characterization of the genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts using Foner Magnetic Method
    Applied Catalysis A: General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    International audienceThe genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method

Galina V. Pankina - One of the best experts on this subject based on the ideXlab platform.

  • Study the hematite reduction kinetics by the Magnetic Method
    Thermochimica Acta, 2020
    Co-Authors: Petr A. Chernavskii, Galina V. Pankina, Sergey V. Maksimov, N.v. Kim, Alla A. Novakova
    Abstract:

    Abstract This study is devoted to the reduction of Fe2O3 supported on silica gel in H2 in the temperature range of 290–600 °C. A continuous magnetization measurement Method was used to obtain the temperature programmed reduction (TPR) profile. The influence of the external Magnetic field on the dynamics of the process is investigated. It was shown that the TPR profile depends both on the magnitude of the applied field and on the particle size of hematite.

  • Formation of Co-Ru/MgO/Al2O3 catalysts for the Fischer-Tropsch synthesis: A Magnetic Method for the estimation of cobalt particle size
    Kinetics and Catalysis, 2007
    Co-Authors: Galina V. Pankina, Petr A. Chernavskii, A. Yu. Krylova, V. V. Lunin
    Abstract:

    The physicochemical properties of Co-supported catalysts were studied, and the particle size of Co in Co/MgO/Al2O3 and Co-0.2% Ru/MgO/Al2O3 catalysts for the Fischer-Tropsch synthesis (FTS) was estimated using a Magnetic Method. It was found that a considerable fraction of superparaMagnetic Co particles, which increase selectivity for C5+ hydrocarbons and decrease the yield of methane in the FTS, was present in a ruthenium-containing catalyst along with single-domain ferroMagnetic particles. In this case, the catalyst activity increased by a factor of 10.

  • Characterization of the Genesis of Cobalt Metal Particles in Silica-Supported Fischer-Tropsch Catalysts using Foner Magnetic Method
    Applied Catalysis A : General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    The genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method.

  • In situ characterization of the genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts using Foner Magnetic Method
    Applied Catalysis A: General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    International audienceThe genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method

Jean-sébastien Girardon - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the Genesis of Cobalt Metal Particles in Silica-Supported Fischer-Tropsch Catalysts using Foner Magnetic Method
    Applied Catalysis A : General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    The genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method.

  • In situ characterization of the genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts using Foner Magnetic Method
    Applied Catalysis A: General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    International audienceThe genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method

Andrei Y Khodakov - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the Genesis of Cobalt Metal Particles in Silica-Supported Fischer-Tropsch Catalysts using Foner Magnetic Method
    Applied Catalysis A : General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    The genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method.

  • In situ characterization of the genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts using Foner Magnetic Method
    Applied Catalysis A: General, 2006
    Co-Authors: Petr A. Chernavskii, Jean-sébastien Girardon, Andrei Y Khodakov, Galina V. Pankina, Elodie Quinet
    Abstract:

    International audienceThe genesis of cobalt metal particles in silica-supported Fischer-Tropsch catalysts was studied using in situ Foner vibrating-sample Magnetic Method. The cobalt promoted and unpromoted catalysts were prepared by aqueous (co)-impregnation using cobalt nitrate or acetate, ruthenium nitrosyl nitrate or perrhenic acid followed by oxidative pre-treatment in air and reduction in hydrogen. In several catalyst preparations, sucrose was added to the impregnating solutions. The genesis of cobalt metal phases in these catalysts was monitored in situ by the Magnetic Method during the temperature-programmed reduction in pure hydrogen. A considerably higher extent of cobalt reduction was found in the catalysts prepared from cobalt nitrate than in those prepared from cobalt acetate. Promotion with ruthenium and rhenium results in a considerable decrease in the temperature of the emergence of cobalt metal phases. Small superparaMagnetic, single-domain and multi-domain ferroMagnetic cobalt metal particles were observed in the reduced catalysts by the Magnetic Method. It was found that lower temperature calcination of the cobalt catalysts prepared from cobalt nitrate and addition of sucrose to the impregnating solution lead to a decrease in the concentration of multi-domain cobalt ferroMagnetic metal particles and to an increase in the fraction of superparaMagnetic cobalt particles. SuperparaMagnetic cobalt particles smaller than 6-7 nm were detected in the reduced catalysts prepared from cobalt nitrate with sucrose addition and in the catalysts prepared from cobalt acetate. Catalyst characterization using X-ray diffraction and X-ray photoelectron spectroscopy has confirmed the results about cobalt dispersion and reducibility in the cobalt silica-supported catalysts obtained by the Foner Magnetic Method