Collect. Czech. Chem. Commun. 1987, 52, 678-685

The influence of the structure of molybdenum disulphide on its reactivity

Lidmila Bartovská and Čestmír Černý

Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


The equilibrium in the system Mo-MoS2-H2S-H2 was studied between 569.4 and 1 276.8 K. The equilibrium gaseous mixture was analyzed by an iodometric method, the solid phase was studied by X-ray powder diffraction. The structure of MoS2 changed in the course of measurements from a “poorly crystalline” form at lower temperatures to a “well crystalline” one with a small number of stacking faults at higher temperatures. The poorly crystalline form is more reactive than the well crystalline one. For the formation of the well crystalline form of MoS2 a Gibbs-energy equation, ΔG0 (J mol-1) = -390 100 + 176.7T, was derived. It is in excellent agreement with the equation derived from the data obtained by fluorine calorimetry.