Dependence of oxidation reactivity on optical textures of cokes and solid carbons and oxygen functionalities on carbon surfaces

摘要

Properties of cokes and carbon materials depend on structure at three different scales,atomic(bonding),nanostracture(aggregation of crystallites),and microstructure(optical texture)1.Polarized-light microscopy(PLM)has been used to characterize the optical texture of cokes and carbons to assess the extent of their microstructural anisotropy.Oxidation reactivity can be measured as a function of temperature,using a Temperature-Programmed Oxidation analysis(TPO).TPO has been used in a range of studies from understanding the mechanisms of carbon deposition on metal surfaces in engine fuel systems to assessing the degree of graphitization in heat treated carbons.For the applications of activated carbons,surface functional groups affect the performance in adsorption processes or as catalyst supports in chemical reactions4.Temperature-Programmed Desorption(TPD)can be used to characterize surface functional groups5.This work presents findings on the relationships between optical texture and oxidation reactivity of anisotropic carbons and the effects of surface groups on the oxidation reactivity of adsorbent carbons.