Synthesis and characterization of ruthenium supported on carbon nanofibers with different graphitic plane arrangements

Ruthenium supported on carbon nanofibers with different structures with respect to the arrangement of the graphitic planes (platelet, fishbone and tubular) have been prepared by wet impregnation method. On the other hand, the CNFs were prepared by CVD method at different temperatures using C2H4 as the carbon precursor and Ni/SiO2 as the catalyst. Different techniques have been employed to characterize both the supports and the final Ru catalysts: N2 adsorption–desorption analyses, XRD, TEM, elemental analyses, TPD, TPR, H2 chemisorption, TPO, atomic absorption spectrophotometry and titration analyses. The results show that, depending on the orientation of the graphitic plane, the amount of acidic oxygen-containing groups can change significantly when the Ru was added to the CNFs. Thus, the specific surface area of CNF tubular was increased when Ru particles were impregnated. It was due to the oxygen groups were increased in comparison with other CNF types. In turn, the Ru particle size, its dispersion and its interaction with the support were clearly influenced by these oxygen-containing groups. Therefore, it was demonstrated that the presence of more acidic groups stabilizes the Ru particles during reduction.