Preparation and characterization of supports with a synthesized layer of catalytic filamentous carbon: III. Synthesis of carbon nanofibers on nickel supported onto aluminum oxide

Abstract

The synthesis of catalytic filamentous carbon (CFC) on catalysts prepared by supporting Ni2+ compounds onto the surface of various alumina modifications (macroporous α-Al2O3 and mesoporous ϑ-Al2O3 and δ-Al2O3) using two procedures (impregnation and homogeneous precipitation) was studied. The texture characteristics (specific surface area and pore structure) of the parent supports and adsorbents with a CFC layer were compared. The effect of the supporting procedure on the surface morphology of Ni/Al2O3 catalysts and the synthesized CFC layer was studied by scanning electron microscopy. It was found that the carbon yield on a macroporous catalyst prepared by homogeneous precipitation was higher than that on a catalyst prepared by impregnation by a factor of ∼2. The CFC layer exhibited a mesoporous structure because of a chaotic interlacing of carbon nanofibers, and the synthesis of CFC on macroporous supports resulted in the formation of a bidisperse pore structure of the adsorbent. Active and stable heterogeneous biocatalysts were prepared by the adsorptive immobilization of enzymatically active substances (glucoamylase and nongrowing baker’s yeast cells) on CFC.