Permeability of sintered microfibrous composites for heterogeneous catalysis and other chemical processing opportunities

Cahela, Donald R.; Tatarchuk, Bruce J.

doi:10.1016/s0920-5861(01)00352-2

Cited by 60 publications

(35 citation statements)

References 9 publications

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“…This catalyst design decreases internal diffusion limitations, reducing the amount of catalyst required. High thermal conductivity of the metal SMF provides a radial heat transfer twice that of randomly packed catalytic beds [15], leading to nearly isothermal conditions during exothermic reaction operation. Fig.…”

Section: Catalyst Characterizationmentioning

confidence: 99%

Structured fiber supports for ionic liquid-phase catalysis used in gas-phase continuous hydrogenation

Ruta

Yuranov

Dyson

et al. 2007

Journal of Catalysis

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Structured supported ionic liquid-phase (SSILP) catalysis is a new concept with the advantages of ionic liquids (ILs) used as solvents for homogeneous catalyst and the further benefits of structured heterogeneous catalysts. This is achieved by confining the IL with the transition metal complex to the surface of a structured support consisting of sintered metal fibers (SMFs). In an attempt to improve the homogeneity of the IL film, the SMFs were coated by a layer of carbon nanofibers (CNFs). The IL thin film immobilized on CNF/SMF supports presents a high interface area, ensuring efficient use of the transition metal catalyst. The regular structure of the support with high porosity (>0.8) allows a low pressure drop and even gas-flow distribution in a fixed-bed reactor. The high thermoconductivity of the CNF/SMF support suppresses the formation of hot spots during exothermic hydrogenation reactions. The selective gas-phase hydrogenation of 1,3-cyclohexadiene to cyclohexene over a homogeneous Rh catalyst immobilized in IL supported on CNF/SMF was used as a test reaction to demonstrate the feasibility of the SSILP concept. The catalyst [Rh(H) 2 Cl(PPh 3 ) 3 /IL/CNF/SMF] showed a turnover frequency of 150-250 h −1 and a selectivity of >96%. High-pressure 1 H NMR and 1 H{ 31 P} NMR spectroscopy was used to provide insights into the nature of the active catalytic species.

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Section: Catalyst Characterizationmentioning

confidence: 99%

Structured fiber supports for ionic liquid-phase catalysis used in gas-phase continuous hydrogenation

Ruta

Yuranov

Dyson

et al. 2007

Journal of Catalysis

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“…Fibers made of special alloys (stainless steel, Inconel, Fecralloy) exhibit high mechanical strength, chemical and thermal stability. The high thermal conductivity of the metal fibers matrix provides a radial heat transfer coefficient two-fold higher compared to randomly packed catalytic beds [11]. This results in nearly isothermal conditions when used as catalytic materials for highly exo/ endothermic reactions.…”

Section: Introductionmentioning

confidence: 99%

Palladium on carbon nanofibers grown on metallic filters as novel structured catalyst

Tribolet

Kiwi‐Minsker

2005

Catalysis Today

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A novel composite material based on carbon nanofibers (CNF) grown on sintered metal fibers (SMF Inconel ) filter was investigated for its favorable properties as catalytic support. The CNF were formed directly over the SMF Inconel by thermal (650 8C) chemical vapor deposition of ethane-hydrogen mixture. The CNF/SMF Inconel composite consists of metal fibers entangled by CNF network of microns thickness and strongly anchored to the metal surface. The properties of the CNF/SMF Inconel were controlled by the synthesis conditions. The CNF coating reduced the filter porosity and decreased the material permeability, but the pressure drop during the gas passage through the reactor remained low for CNF fraction <10%. Palladium was deposited on CNF previously activated by boiling in hydrogen peroxide. The activity and selectivity of Pd8/CNF/SMF Inconel catalysts were tested in the selective hydrogenation of acetylene and compared with Pd supported on activated carbon fibers (Pd8/ACF). The TOF was one order of magnitude higher for Pd8/CNF/SMF Inconel as compared to Pd8/ACF. This effect was attributed to a strong metal-support interaction of Pd8-nanoparticles with the graphitized CNF. The reaction was found to be structure sensitive leading to a decrease of TOF for the Pd8-particles <3 nm. #

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“…Fibers made of special alloys (stainless steel, Inconel, Fecralloy) exhibit high mechanical strength, chemical and thermal stability. High thermal conductivity of the metal fiber matrix provides a radial heat transfer coefficient twofold higher compared to randomly packed catalytic beds [16]. This results in nearly isothermal conditions when used as catalytic materials for highly exo/endothermic reactions.…”

Section: Introductionmentioning

confidence: 99%

Carbon nanofibers grown on metallic filters as novel catalytic materials

Tribolet

Kiwi‐Minsker

2005

Catalysis Today

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Carbon nanofibers (CNF) were synthesized on sintered metal fibers (SMF) filters of nickel and Ni-containing alloys (Inconel, stainless steel (SS)) by thermal chemical vapor deposition of ethane in the presence of hydrogen at $660 8C. The CNFs were formed directly over the SMF filters without deposition of metal particles. The catalytic active sites leading to the CNF formation were attained by oxidation-reduction of the SMF filter. The CNFs present platelet morphology as determined by X-ray diffraction and transmission electron microscopy. The CNF/ SMF composites have thin carbon layer in the microns range strongly anchored to the metal surface. The initial open structure of SMF filters is preserved. Scanning electron microscopy together with temperature programmed oxidation suggests the formation of uniform CNFs deposits on SMF Inconel with fiber's diameters in the range of 70 nm. Carbon deposits with a different nature were observed over SMF Ni and SMF ss .The CNF/SMF Inconel composites have high specific surface area due to mesopores of CNFs, high thermo-conductivity and open 3D macrostructure. This is advantageous for catalytic applications, especially during the catalysis of highly exo/endothermic reactions in reactors with structured catalytic bed. #

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Permeability of sintered microfibrous composites for heterogeneous catalysis and other chemical processing opportunities

Cited by 60 publications

References 9 publications

Structured fiber supports for ionic liquid-phase catalysis used in gas-phase continuous hydrogenation

Structured fiber supports for ionic liquid-phase catalysis used in gas-phase continuous hydrogenation

Palladium on carbon nanofibers grown on metallic filters as novel structured catalyst

Carbon nanofibers grown on metallic filters as novel catalytic materials

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