MONITORING OF CHEMICAL-REACTIONS - IN-SITU COMBINATION OF XAFS AND DIFFERENTIAL SCANNING CALORIMETRY (DSC)

Differential scanning calorimetry (DSC) is a well-established method t o study energetic changes in solid or liquid samples with high accurac y. We combined in situ XAFS in transmission mode (QEXAFS) with DSC. Th is allows to simultaneously monitor local structural and enthalpic cha nges during the course of chemical reactions and phase transitions. Th e new technique is applicable to crystalline, non-crystalline (e.g. gl assy or amorphous) and liquid systems. We studied the decomposition of silver carbonate to silver(I)oxide. At present, a time resolution of ca. 10 s corresponding to a temperature resolution of around 0.3 K is easily achieved. Reaction extents of the above reaction are individual ly calculated from both DSC and XAFS measurements and compared to each other.