Search

The synthesis of a layer of catalytic filamentous carbon (CFC) on a Co catalyst supported by homogeneous precipitation onto the surface of aluminosilicate supports (ceramic foam and vermiculite) was studied. The effects of CFC layer synthesis conditions (the catalyst concentration on a support, the pyrolysis temperature of a propane-butane mixture, and the composition of the gas mixture) on the specific surface areas of supports, the yield of carbon (g C)/(g Co)), and the morphology of a surface CFC layer were examined. It was found that, in the case of ceramic foam, the concentration of cobalt hydroxide precipitated on the surface was lower by a factor of 15 and the yield of carbon was higher by a factor of 20–40 than those in vermiculite. The specific surface areas of supports, the yield of carbon, and the amount of synthesized carbon increased as the pyrolysis temperature of a propane-butane mixture was increased from 500 to 600°C. As found by scanning electron microscopy, the carbon content increased with pyrolysis temperature because of an increase in the length of carbon nanofibers. The properties (activity and stability) of biocatalysts prepared by the adsorption immobilization of a recombinant protein having glucose isomerase activity on CFC-Co-containing supports (ceramic foam and vermiculite) were studied. [ABSTRACT FROM AUTHOR]

The synthesis of catalytic filamentous carbon (CFC) on a Ni catalyst supported by homogeneous precipitation onto the surface of aluminosilicate ceramic supports (honeycomb monoliths, ceramic foam, glass foam, and haydite) was studied. The effects of CFC synthesis conditions (the catalyst concentration on a support, the pyrolysis temperature of a propane-butane mixture, and the composition of the gas mixture) on the specific surface areas of supports, the yield of carbon, and the morphology of a surface CFC layer were examined. As found by scanning electron microscopy, the uniformity of distribution and the size of carbon nanofibers synthesized depended on the conditions of their synthesis. The resulting CFC-containing supports were tested as adsorbents for the immobilization of enzymatically active substances (individual enzymes, cell membranes, and microorganisms) in order to prepare highly stable heterogeneous catalysts for biotechnology and biocatalysis. [ABSTRACT FROM AUTHOR]

Abstract: Physical and chemical properties of TSEFLAR™-treated gibbsite/hydrargillite (centrifugal thermal activation) CTA HG were studied with X-ray analysis, TA, EM, BET and IRS. CTA HG product obtained at the temperature range of 330–580°C and contact time ∼1s is the one with a transitional non-equilibrated layered hydroxide structure with partly lost hydroxide groups. The CTA HG structure does not correspond to the produced chemical composition Al2O3·(0.4–2)H2O and, therefore, the products reveal a higher reactivity. Such products are already readily hydrated at room temperature in water and aqueous ammonia to form eventually the stable bayerite-like hydroxide structure. [Copyright &y& Elsevier]