Jose Guadalupe Santiesteban

Carbon Nanotubes Prepared by Catalytic Decomposition of Benzene Over Silica Supported Cobalt Catalysts

Abstract Carbon nanostructures were prepared by catalytic decomposition of benzene on Co/SiO2 catalysts at 873 K. As a function of particle size and reactive mixture, carbon filaments and nanotubes were obtained and various shapes observed such as straight, curved and helically-coiled nanotubes. Particularly, it was shown that the helically-coiled nanotubes do not present an ordered atomic structure as it was predicted theoretically. However, the active catalytic particle as well as the reactive environment may play an important role in the growth of such nanostructures.

On the atomic structure of Fe/Mn promoted sulfated zirconia

Abstract The aim of the present work is to shed some light on the surface atomic structure of an Fe Mn-promoted sulfated zirconia catalyst using high-resolution transmission electron microscopy (HRTEM) imaging. The presence of Fe and Mn species, which were found to be dispersed at a molecular level, were apparent on the {{001}} and {{110}} surfaces of zirconia particles. A combination of the present results with additional detailed studies using other physicochemical characterization techniques is needed to elucidate the atomic configuration of the active sites responsible for the enhanced catalytic activity of the Fe Mn-promoted sulfated zirconia catalyst.