Surface Chemistry, Porous Texture, and Morphology of N-Doped Carbon Xerogels

N-doped carbon xerogels were obtained from organic xerogels prepared using different N-containing organic compounds, including 3-hydroxy aniline, melamine, and 3-hydroxy pyridine. Carbonization was carried out between 500 and 900 degrees C. The surface chemistry of samples was determined by elemental analysis and X-ray photoelectron spectroscopy, their porous texture was determined by N-2 and CO2 adsorption at - 196 and 0 degrees C, respectively, and their morphology was determined by scanning electron microscopy. N-doped carbon xerogels with a wide variety of N contents and functionalities were obtained according to the ingredients and carbonization temperature used. Carbon xerogels contained, in different proportions, three/four N functionalities: pyridinic, pyrrolic and/or pyridonic, and quaternary N functionalities. They were microporous carbons with narrow micropores that had constrictions at their entrances, producing higher CO2- than N-2-determined micropore surface areas. Morphology studies showed samples to be constituted by isolated microspheres or microsphere clusters. Microsphere diameters depended on the recipe and carbonization temperature used.