XPS Studies of Residues from Liquefaction of Blind Canyon Coal Mixed with an Iron-Based Catalyst

Abstract

X-ray photoelectron spectroscopy (XPS) has been used to investigate the surface and bulk characteristics of residue from liquefaction of Blind Canyon coal mixed with an iron-based catalyst. The liquefaction of Blind Canyon coal was investigated at three different processing times (17, 30, and 60 min); residues were studied by XPS. It is shown that the concentration of elements at the outermost surface layer of samples, measured by XPS, is different from the bulk. Ar+ ion sputtering followed by XPS was carried out to delineate the differences in the distribution of elements and chemical changes that occurred as the exposed surface varied from initial surface to the bulk. The elemental composition of the catalyst mixed with coal residue surface changes with time of Ar+ ion sputtering, i.e., with the depth from the initial surface of the coal residue particles. The S/Fe (catalyst element) ratio, which was initially greater than 1, decreases to less than 1 as time of Ar+ ion sputtering is increased.

Efficient Synthesis of Heteroatom (N or S)‐Doped Graphene Based on Ultrathin Graphene Oxide‐Porous Silica Sheets for Oxygen Reduction Reactions

“…The former two peaks are in agreement with the reported 2p 3/2 (S1) and 2p 1/2 (S2) positions of thiophene‐S owing to their spin‐orbit coupling 30, 31. The third peak should arise from some oxidized sulfur (S3)31, 32 in SG, whose XPS intensity significantly decreases with increasing the annealing temperature, indicating the lower stability of such species at higher temperature. Other sulfur components such as thiol (SH) at around 162.0 eV30, 33 can not be detected in the XPS spectra.…”

Facile Synthesis of Nitrogen and Sulfur Dual-doped Hierarchical Micro/mesoporous Carbon Foams as Efficient Metal-free Electrocatalysts for Oxygen Reduction Reaction

“…The former two peaks are in agreement with the reported 2p3/2 (S1) and 2p1/2 (S2) positions of thiophene-S owing to their spin-orbit coupling [42]. The third peak should arise from some oxidized sulfur (SOx, S3) in NS-MC composites [43,44], whose XPS intensity significantly increased with the increase of the annealing temperature (Table S1), indicating the higher stability of such species at higher temperature. Other sulfur components such as thiol (SH) at around 162.0 eV can not be detected in the XPS spectra [42,45].…”

Electrocatalytic Activity of Nanocomposites of Sulphur Doped Graphene Oxide and Nanosized Cobalt Phthalocyanines

“…High resolution S2p peaks were used to probe the chemical state of rSDGONS. Figure B shows effective doping of sulphur into the graphene carbon network to form thiophene moieties centred at 163,97 and 165.18 in agreement with the reported 2p 3/2 and 2p 1/2 assignment, as a result of spin orbit coupling . There is also evidence for oxidised sulphur at 166.38 and 167.56 which may be attributed to sulphite and sulphates respectively.…”