Relation between the Infrared Spectra and the Lateral Specific Surface Areas of Gibbsite Samples
Relation between the Infrared Spectra and the Lateral Specific Surface Areas of Gibbsite Samples
复制标题
三水铝石样品的红外光谱与横向比表面积的关系
作者：
N. Phambu;and Bernard Humbert;A. Burneau
Al(OH)3晶体样品的化学行为受侧基比的控制。对于具有两种明显空间分离表面的结晶良好的三水铝石样品，红外吸收光谱中在~ 3460 cm-1处的振动成分（未显示在拉曼光谱中）随着气体吸附等温线确定的横向比面积线性增加。这种强烈而宽阔的线条与存在于边缘面上的AlOH1/2 +或AlOH1/2-的羟基拉伸模式有关。然而，将这一波段指定为这些物种中的一种或另一种模式过于简单。还应考虑结合两种物种的更复杂的结构。当抽真空的样品在短时间内进行D2O蒸汽注入时，OD光谱区域在2563 cm-1处显示出一个宽的组分，对应于OH区域的3460 cm-1波段，而不对应于大块羟基的其他模式。这一实验观察结果也与……
The chemical behavior of crystalline Al(OH)3 samples is governed by the lateral-to-basal surface ratio. For well-crystallized gibbsite samples possessing the two types of surfaces clearly spatially separated, a vibrational component at ∼3460 cm-1 in the infrared absorption spectra, not displayed in the Raman spectra, increases linearly with the lateral specific area determined by a gas adsorption isotherm. This intense and broad line is related to hydroxyl stretching modes of AlOH21/2+ or AlOH1/2- species present on the edge faces. However, it is too simplistic to assign this band to a mode of one or the other of these species. More complex structures combining both species should also be considered. When an evacuated sample is submitted during a short time to a D2O vapor injection, the OD spectral region displays essentially one broad component at 2563 cm-1, corresponding to the 3460 cm-1 band in the OH region and not to the other modes of the bulk hydroxyls. This experimental observation is also in agre...