Role of Carbon Order in Structural Transformations and Hydrogen Evolution Induced by Reactive Ball Milling in Cyclohexene


Demineralized Summit (DS) anthracite, DS annealed at 1673 K, and graphite are used to explore the effect of precursor order on structural transformations and H2 evolution that result during reactive ball milling. Carbon structure was assessed before and after milling with temperature-programmed oxidation, X-ray diffraction (XRD), ultraviolet Raman spectroscopy, N2 adsorption, He density, and solvent swelling. Graphite milled in cyclohexene is primarily nanocrystalline graphite, with 8 wt % amorphous content leading to low-temperature oxidation, swelling, increased surface area and mesoporosity. Milling the disordered DS leads to signs of increased sp2 clustering, increased cross-linking, a significant ultramicroporosity with pores less than 8 Å, and low-temperature H2 evolution. The carbon fraction of annealed DS behaves similarly to graphite in the mill.


Chemical and Biochemical Engineering


United States. Department of Energy
Consortium for Premium Carbon Products from Coal


This work was funded through the U.S. Department of Energy University Coal Research Program (DEFG26-06NT42675) and Consortium for Premium Carbon Products from Coal (DEFC2603NT41874, Internal Agreement No. 2875-TPSU-DOE-1874).

Keywords and Phrases

Amorphous contents; Before and after; Carbon fractions; Carbon structures; Cyclohexene; He densities; Hydrogen evolutions; Meso porosities; Nanocrystalline graphites; Reactive ball millings; Solvent swellings; Structural transformations; Surface areas; Temperature oxidations; Ultraviolet raman spectroscopies; X-ray diffractions; Adsorption; Amorphous materials; Carbon; Chemical oxygen demand; Dielectric relaxation; Graphite; Grinding (machining); Helium; Hydrogen; Milling (machining); Milling machines; Olefins; Oxidation; X ray analysis; Ball milling

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Article - Journal

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© 2008 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Oct 2008