A THERMODESORPTION STUDY OF FIRST STAGE GRAPHITE FECL3 INTERCALATION COMPOUNDS

With the aim of synthesizing carbonaceous materials with specific adso rbent properties obtained from the pyrolysis of mixtures of coal tar p itch (CTP) and FeCl3 graphite intercalation compounds (GIG), we presen t a study of the thermodesorption of first stage FeCl3 GIC. These GICs were synthesized in a two temperature reactor with several kinds of g raphites characterized by different granulometry and crystallinity (on e a monocrystalline graphite and the others, polycrystalline). During heating under an inert atmosphere, FeCl3 is decomposed into FeCl2 and partially sublimed. At 500 degrees C, second stage FeCl2 GIC reflectio ns are observed on X-ray diffractograms, and at 750 degrees C, all iro n and chlorine are desorbed out of the graphene layers in polycrystall ine graphite, whereas monocrystalline graphite always contains some am ount of iron and chlorine. Thermogravimetric evolution has been follow ed using a McBain balance. FeCl3 desorption mainly occurs between 350 and 550 degrees C, and is more quantitative in the case of polycrystal line materials. The graphite granulometry significantly influences the desorption level, and the higher the heating rate, the greater the Fe Cl3 desorption.