Carbon nanofibers grown on metallic filters as novel catalytic materials
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 not, vert, similar660 °C. 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 SMFInconel with fiber's diameters in the range of 70 nm. Carbon deposits with a different nature were observed over SMFNi and SMFss. The CNF/SMFInconel 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.