Mitra, S
1997
Investigation of the Molecular Structure of Organic Sulfur in Coal by XAFS Spectroscopy
Huffman, G.P.; Huggins, F.E.; Mitra, S.; Shah, N.; Pugmire, R.J.; Davis, B.H.; Lytle, F.W. and Greegor, R.B.
Energy & Fuels, 3, 200, 1989. Funded by US Department of Energy.
X-ray absorption fine structure (XAFS) spectroscopy has been used to investigate the molecular structure of organic sulfur in a suite of maceral separates and in several biodesulfurized and extracted coal specimens. For most samples, the X-ray absorption near-edge structure (XANES) exhibits sharp peaks just above the absorption edge that are characteristic of s Æ p transitions of compounds containing an aromatically bound sulfur atom and a broad, structured maximum at somewhat higher energies. The latter maximum is believed to arise from resonant backscattering of photoelectrons by carbon atoms 3.5-4.1 Å from the sulfur atom and possibly from s Æ p transitions of sulfur bonded to oxygen. The radial structure functions derived by Fourier analysis of the EXAFS exhibit peaks at distances that are compatible with the first three neighbor shells surrounding an aromatically bound sulfur atom.
Mitra, S
1997
Investigation of the Molecular Structure of Organic Sulfur in Coal by XAFS Spectroscopy
Huffman, G.P.; Huggins, F.E.; Mitra, S.; Shah, N.; Pugmire, R.J.; Davis, B.H.; Lytle, F.W. and Greegor, R.B.
Energy & Fuels, 3, 200, 1989. Funded by US Department of Energy.
X-ray absorption fine structure (XAFS) spectroscopy has been used to investigate the molecular structure of organic sulfur in a suite of maceral separates and in several biodesulfurized and extracted coal specimens. For most samples, the X-ray absorption near-edge structure (XANES) exhibits sharp peaks just above the absorption edge that are characteristic of s Æ p transitions of compounds containing an aromatically bound sulfur atom and a broad, structured maximum at somewhat higher energies. The latter maximum is believed to arise from resonant backscattering of photoelectrons by carbon atoms 3.5-4.1 Å from the sulfur atom and possibly from s Æ p transitions of sulfur bonded to oxygen. The radial structure functions derived by Fourier analysis of the EXAFS exhibit peaks at distances that are compatible with the first three neighbor shells surrounding an aromatically bound sulfur atom.