Relating the Nonideal Diffraction from the Graphene Layer Stacking Peak to the Aliphatic Carbon Abundance in Bituminous Coals

Abstract

Using conventional powder diffractometry and monochromatic Cu Ka X-rays, five of the Argonne Premium Coals have been examined in an attempt to better understand their molecular-level structuring. The diffractograms have been separated into contributions from mineral diffraction, amorphous scattering, and nonideal diffraction, with the latter due to small and nearly planar polycyclic aromatics termed graphenes. Correlation of the diffuse graphene layer stacking peak in each diffractogram with the percentage of aliphatic carbon in the coal suggests that the aliphatic moieties in these bituminous coals cause distortions (nonuniform strains) in the stacking of the graphene units which in turn cause the diffuseness of this peak.

Direct synthesis of 3D hollow porous graphene balls from coal tar pitch for high performance supercapacitors

“…Primitive graphene layers in parent coals have been investigated at the molecular level. 20,21 The abundant polyaromatic structures with a narrow size distribution in coal tar pitch are quite similar to the graphene structure, which contains bonds between sp 2 -hybridized carbons. This property makes it possible to directly synthesize PG from coal tar pitch.…”

Interlayer Structural Models of Beulah Zap Lignite Based on Its Wide Angle X-ray Scattering

“…Fourier transform of the phase interference curve (in reciprocal space) into the 1-D structure curve (in molecular space) has been accomplished by M ( q ) and the exponential are conventional sharpening and dampening terms used for converting the distribution function from one that describes electron-pair distances to one that describes atom-pair distances. , The limits on the integral are q min = 0.5 Å -1 and q max = 2.4 Å -1 , which limits the resulting structure curve to describing the interlayer atom-pair distances in BZ coals. ,− ,, The Fourier transform terminates prior to the (111) and the (200) diffraction peaks of the aluminum sampleholder. In this calculation, Δ q = 0.1 Å -1 .…”

“…A sample of BZ was mounted onto an aluminum sampleholder and mounted into our θ−2θ diffractometer, which is equipped with a sample spinner and a θ-compensating slit. − The aluminum sampleholder is disk-shaped with a diameter of 2.5 cm and a depth of 1 mm. A wide-angle X-ray diffractogram (WAXRD) was obtained using Cu Kα Xrays as the radiation source, and a graphite crystal monochromator in the secondary X-ray beam was obtained over the angular region from 2θ = 5.00° to 2θ = 75.00° (or q = 0.36−5.00 Å -1 ) at increments of Δ2θ = 0.02° for 3‘ intervals at each angle.…”

Constitution of Illinois No. 6 Argonne Premium Coal: A Review

“…The aromatic moieties present in coal structures have been characterized using nuclear magnetic resonance (NMR), [9][10][11][12][13] X-ray diffraction (XRD), 14 high-resolution transmission electron microscopy (HRTEM), [15][16][17][18] and ruthenium ion catalyzed oxidation (RICO). 19,20 Solum et al, 9 dela Rosa et al, 11 …”