煤中氢键类型的研究煤中氢键类型的研究

TYPE OF HYDROGEN BONDS IN COAL

采用真空红外光谱技术清晰地观察到了碳含量７３～８８ｗ％（ｄａｆ）的四个煤样及其溶剂抽出物中的五种羟基的不同氢键缔合类型，并通过原位热解红外光谱技术研究了它们的热稳定性。结果表明，它们的热稳定性顺序为：ＯＨ…π＜ＯＨ…Ｎ＜ＯＨ自缔合≈环状四聚体ＯＨ＜ＯＨ…醚氧。

Hydroxyl is a main functional group in forming hydrogen bonds with various hydrogenbondingacceptors However, its type is hard to be distinguished by normal FTIR method because the hydroxyl absorption peak is broad and overlaps with that of water in coal In this work, vacuum FTIR method was employed to overcome this problem Five hydroxyl absorption peaks assigned to different type of hydrogen bonds were observed clearly in vacuum FTIR spectra Although the type of hydrogen bonds varies with coal rank, selfassociated OH groups and OH…N are two major hydrogen bonds in raw coal and extracts The thermal stability of these hydrogen bonds was investigated by insitu pyrolysis FTIR and followed the order of OH…π<OH…N<selfassociated OH groups≈cyclic OH tetramers<OH…ether O