CHARACTERIZATION OF OXYGEN-CONTAINING SURFACE COMPLEXES CREATED ON A MICROPOROUS CARBON BY AIR AND NITRIC-ACID TREATMENT

The nature and extent of oxygen functional groups present on the surface of a microporous carbon has been studied. The carbon was prepared by the carbonization of a porous phenol-formaldehyde resin in N2 at 1273 K. Following preparation, samples of the carbon were carefully oxidized in either air or concentrated HNO3 at various temperatures and times to form oxygen complexes. The complexes were characterized by use of both a linear temperature programmed desorption (LTPD) technique and selective neutralization. Four characteristic groups of oxygen complexes are defined on the basis of the decomposition product gases and the thermal stabilities of the complex. Detailed studies are made of the nature and structure of the acidic, CO2-evolving surface complexes.