Catalysis Today, Vol.344, 32-40, 2020
Nitrogen-doped carbonaceous materials obtained by CVD process from mesoporous silica for sulfides oxidation
In this work, we describe the synthesis of N doped carbon nanomaterials from mesoporous silica impregnated with iron (10 wt%), using acetonitrile as carbon and nitrogen source by CVD process at 600, 650, 700 and 800 degrees C. The obtained materials showed a N/C content between 8.3-10.1% and a carbon content between 14 and 31%. Results of TEM, TG, elemental analysis, Raman spectroscopy and XRD showed that higher temperatures synthesis has led to the formation of high content and more organized carbon nanostructures, i.e., carbon nanotubes and bamboo-like structures with higher nitrogen contents in their structure. On the other hand, XPS results showed that the carbon structures obtained at 800 degrees C have preferential the presence of less reactive nitrogen species, i.e. graphitic nitrogen, while the materials obtained at 600 and 650 degrees C preferentially have the presence of more reactive nitrogen groups such as pyridine. These materials were used as catalysts for the sulfides oxidation. The type of nitrogen group present in the carbon structure influenced directly the activity of the materials. The catalysts obtained at lower temperatures showed the best kinetics of oxidation sulfides, which was related to the presence of a higher content of more reactive nitrogen groups.