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首页> 外文OA文献 >Thermogravimetric analysis-mass spectrometry (TGA-MS) of hydrotalcites containing CO32-, NO3-, Cl-, SO42- or ClO4-
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Thermogravimetric analysis-mass spectrometry (TGA-MS) of hydrotalcites containing CO32-, NO3-, Cl-, SO42- or ClO4-

机译：含有CO32-，NO3-，Cl-，SO42-或ClO4-的水滑石的热重分析质谱（TGA-MS）

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Mg/Al-hydrotalcites containing NO3-, Cl-, SO42- or ClO4- were synthesised under N2 to prevent incorporation of CO32-. The presence of the anions in the hydrotalcite structure was confirmed by infrared and Raman spectroscopy. The CO3- and the NO3-hydrotalcites contained both NO3- and CO32-, while the Cl-hydrotalcite also contained some CO32-. It is known that during thermal treatment of hydrotalcites dehydroxylation and decarbonisation strongly overlap. Mass spectrometry following TGA enables one to identify both reactions. For CO3-hydrotalcite CO2 is released simultaneously with water (dehydroxylation) around 335 degrees Celsius followed by NO around 365 and 500 degrees Celsius. The stability of the NO3-hydrotalcite is different showing a major loss of CO2 and H2O (dehydroxylation) around 410 degrees Celsius with losses of NO around 345 and 450 degrees Celsius. The Cl-hydrotalcite shows a similar behaviour for the H2O loss (dehydroxylation), but Cl is lost over a range from 400 to 900 degrees Celsius and CO2 comes off in steps around 360 and 500 degrees Celsius. Completely different is the thermal behaviour of SO4- and ClO4-hydrotalcites. SO4-hydrotalcite shows a gradual weight-loss due to dehydroxylation with two minor water peaks around 260 and 375 degrees Celsius, while the sulphate remains in the structure. The sulphate is not lost until heated to 900 degrees Celsius. The ClO4-hydrotalcite shows a complex thermal behaviour with 2 steps of water loss around 375 and 440 degrees Celsius, where the second step is accompanied by the loss of O2. A possible explanation is a redox reaction between perchlorate and the cations giving metal-chlorides and O2.
机译：在N2下合成含有NO3-，Cl-，SO42-或ClO4-的Mg / Al水滑石，以防止CO32-的结合。通过红外和拉曼光谱证实了水滑石结构中阴离子的存在。 CO3-和NO3-水滑石同时包含NO3-和CO32-，而Cl-水滑石也包含一些CO32-。已知在水滑石的热处理期间，脱羟基和脱碳强烈重叠。 TGA之后的质谱使人们能够识别这两种反应。对于CO3-水滑石，在335摄氏度左右与水（脱羟基）同时释放CO2，然后在365摄氏度和500摄氏度左右释放NO。 NO3-水滑石的稳定性有所不同，在410摄氏度左右会损失大量的CO2和H2O（脱羟基），而在345摄氏度和450摄氏度左右会损失一氧化氮。 Cl水滑石对H2O的损失（脱羟基）表现出相似的行为，但Cl在400至900摄氏度的范围内损失，而CO2在360至500摄氏度的范围内散失。 SO 4和ClO 4水滑石的热行为完全不同。 SO4-水滑石由于脱羟基作用而逐渐失重，在260和375摄氏度附近有两个较小的水峰，而硫酸盐保留在结构中。直到加热到900摄氏度，硫酸盐才消失。 ClO4-水滑石显示出复杂的热行为，在375摄氏度和440摄氏度左右有两步失水，第二步伴随着O2的流失。可能的解释是高氯酸盐与阳离子之间的氧化还原反应，生成金属氯化物和O2。

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