Surface Complexes on Charcoal. Gas Evolution as a Function of Vapor Adsorption and of High-temperature Evacuation.

Abstract

A high-temperature evacuation technique was applied to the study of several factors in the activation and oxidation of a variety of charcoals or carbon surfaces. Oxygen-containing gases, CO, CO/sub 2/, and H/sub 2/O, were formed by the decomposition of the oxygen surface complex and reduction of the oxides in the ash. Large amounts of H/sub 2/ were evolved. Aging the charcoals in moist air at 50/sup 0/C and 80% relative humidity for a month increased their oxygen content appreciably, but steam activation was found to have little effect on the oxygen content. Adsorption of carbon tetrachloride, chlorobenzene, and water vapor on charcoal at room temperature seemed to have little effect on the oxygen complex as was indicated by a very small gas evolution. Molecular nitrogen did not react with charcoal, but ammonia at 750 to 900/sup 0/C formed a nitrogen complex more stable thermally than the oxygen complex. (BLM)