不同还原程度煤显微组分组表面结构XPS对比分析

对煤岩组分、煤级相近而还原程度不同的平朔煤与神东煤的镜质组及惰质组的表面结构特征进行了XPS分析，揭示碳、氧、氮、硫等元素在它们表面结构中的存在形态及其差异。结果表明，碳在表面结构中存在四种形态C—C或C—H、C—O、C＝O、COO，镜质组的C—C或C—H质量分数较惰质组高，而还原程度较强的平朔煤与还原程度较弱的神东煤相比，其显微组分中C—C或C—H质量分数均较同类型的显微组分高；氧、氮、硫的赋存形态在所有的煤样中差异不大，氧的赋存形态以酚羟基氧为主，神东煤显微组分吸附氧的能力明显高于平朔煤，这是因为神东煤易自燃及燃点较低；氮以吡咯型及吡啶型氮为主，而硫以噻吩型硫为主。因此，还原程度对镜质组及惰质组的表面结构均产生影响，主要表现在C—C或C—H质量分数的差异上。

XPS comparative analysis of coal macerals with different reducibility

Reducibility of coal, like rank and maceral, is one of the main factors influencing the properties of coals. The effect of coal reducibility on structural characteristics of macerals is the basic approach for understanding the difference of coal properties from the molecular viewpoint. XPS（X ray Photoelectron Spectroscopy）analysis was carried out to determine the forms and difference of carbon, oxygen, nitrogen, sulfur on the surface of vitrinite and inertinite from Pingshuo and Shendong coals with similar coal rank and petrographical compositions but different reducibility. The results show that C—C or C—H, C—O, C＝O, COO are four forms of carbon, and vitrinite has higher content of C—C or C—H than inertinite. The macerals of Pingshuo coal with stronger reducibility has higher content of C—C or C—H than those of Shendong coal with weaker reducibility. The forms of the other three elements in all samples are similar. The dominant form of oxygen is phenolic hydroxyl oxygen. Shendong coal macerals have higher capability of adsorbing oxygen than Pingshuo coal macerals, which is the reason that Shendong coal has lower ignition point and is easy spontaneously combusted. The dominant forms of nitrogen are pyridinic and pyrrolic type, while the thiophenic type is the main form of sulfur. The results indicate that the reducibility of coal influences the surface structure of vitrinite and inertinite, whose representation is the different content of C—C or C—H.