XRD Characterization of the Structure of Graphites and Carbon Materials Obtained by the Low-Temperature Graphitization of Coal Tar Pitch

Abstract

The structure of some commercial graphites and carbon materials (CMs) obtained by the low-temperature catalytic graphitization of coal tar pitch with iron salt, needle coke, foamed graphite as the catalysts has been studied. The study was performed using the X-ray diffraction technique with reflections from base plane and their decomposition into two components corresponding to the structural phases of graphite which have different XRD characteristics. Various CMs were compared with respect to the structural phase ratio, distance between polyarene layers in these phases, and sizes of the coherent scattering regions. The (004) reflection provided a better fit of some properties of graphites to the calculated XRD characteristics as compared to calculation from the (002) reflection. In the case of carbonization of coal tar pitch with investigated catalyst additions, prepared carbon materials have a higher degree of graphitization and a crystallite size greater than in the other case of carbonization of the individual pitch. The highest catalytic activity is shown by foamed graphite. It was found that the use of foamed graphite as the catalyst at 800-900 ºC produced carbon materials possessing a crystalline structure with interplanar spacing close to that in commercial graphites, while in the absence of catalyst the coal tar pitch material has an amorphous structure.

Direct Synthesis of Porous Carbon Materials Prepared from Diethyldithiocarbamate Metal Complexes and Their Electrochemical Behavior

“…These asymmetric (002) peaks are consistent with carbon structures presenting different interplanar distances, <d 002 >, associated to the in-plane graphite-like lattice parameter, <a>. 29 This peak asymmetry is also associated to the presence of another peak in its left-hand side, assigned as γ in Figures 2a-2c, related to the packing distance of saturated carbon structures as discussed elsewhere for other carbon materials. 30 These (002) interlayer spacing of graphite, <d 002 > = 3.36 Å, 30 and are consistent with carbon structures presenting low degree of graphitization.…”

Modulated Dehydration for Enhanced Anodic Performance of Bacterial Cellulose derived Carbon Nanofibers

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