关键词: 红外分光光度法, 杂多酸, Ｘ射线衍射分析, 热稳定性, 钨酸, 示差扫描量热法, 热重量分析, 硅酸, 钼酸, 锗酸

In this paper, the thermal stability of heteropolyacids with Keggin struc ture HnXM12O40 (X=Si, P, Ge; M=Mo, W) were studied systematically by DSC, TG-DAT, X-ray diffraction, IR spectra at various temperatures and solubility experimental methods. The new criterion of thermal decomposition for heteropoly compounds was proposed. The mechanism of thermal decomposition for heteropolyacids with Keggin structure was presented. A semi-empirical equation being used to predict the thermal decomposition temperatures was obtained. The reaction order and activation energy in every step of loss weight was calculated.

Key words: INFRARED SPECTROPHOTOMETRY, HETEROPOLYACID, X-RAY DIFFRACTION ANALYSIS, THERMAL STABILITY, TUNGSTIC ACID, DIFFERENTIAL SCANNING CALORIMETRY, THERMOGRAVIMETRY, SILICIC ACID, MOLYBDIC ACID