J. Phys. IV France 7 (1997) C2-323-C2-324
Monitoring of Chemical Reactions: In-Situ Combination of XAFS and Differential Scanning Calorimetry (DSC)L. Tröger1, N. Hilbrandt2 and M. Epple3
1 Hamburger Synchrotronstrahlungslabor (HASYLAB), Deutsches Elektronen-Synchrotron (DESY) Notkestr. 85, 22603 Hamburg, Germany
2 Institute of Physical Chemistry, University of Darmstadt, Petersenstr. 20, 64287 Darmstadt Germany
3 Institute of Inorganic and Applied Chemistry, University of Hamburg Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
Differential scanning calorimetry (DSC) is a well-established method to study energetic changes in solid or liquid samples with high accuracy. We combined in situ XAFS in transmission mode (QEXAFS) with DSC. This allows to simultaneously monitor local structural and enthalpjc changes during the course of chemical reactions and phase transitions. The new technique is applicable to crystalline, non-crystalline (e.g. glassy 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 individually calculated from both DSC and XAFS measurements and compared to each other.
© EDP Sciences 1997