In situ infrared study of the surface oxidation of activated carbon dispersed in potassium bromide

Abstract

Diffuse reflectance FTIR spectroscopy has been used to study heat treatment of activated carbon dispersed in KBr in situ in oxygen at 298–853 K. Cyclic acid anhydride species were formed at moderate temperature but were decomposed at high temperatures for which the dominant products of surface oxidation were epoxides, bridging ether groups, heterocyclic rings containing COCOC groupings, C—P^–K⁺ groups and possibly peroxy groups. The high-temperature breakdown of epoxides either by C—O cleavage to give C—O^–K⁺ groups or by C—C cleavage to give bridging or cyclic ethers was partially reversed on cooling.