Materials Transactions JIM · 2000 · 12 citations · 6 references
Natural SciencesChemistryMaterials ScienceChemical KineticsInorganic ChemistryPhysical ChemistryChemical Kinetics ModelingChemical Reaction KineticsKinetic ModelingNucleationReaction Mechanism AnalysisReaction Mechanism ModelingDisproportionation ReactionsNucleation KineticsOne-dimensional Crystal GrowthRate Constant DeterminationSolid-state Reaction Kinetics
The kinetics of hydrogen-induced disproportionation of Zr2Co was studied by the conventional constant volume method in a temperature range of 773 to 873 K. It was found that Zr2Co disproportionated as 2Zr2Co+3H2 → 3ZrH2+ZrCo2 through a two-step mechanism as 1) Zr2Co+H2 → ZrH2+ZrCo and 2) 2ZrCo+H2 → ZrH2+ZrCo2. The first step was very fast and completed within only 100 s at 773 K . The rate, however, decreased with increases in temperature. The apparent rate constant for the first step disproportionation was determined to be k=2.0×10−2exp[15.0×103(J/mol)⁄RT], where the kinetics could be explained by nucleation and one-dimensional growth model. The kinetics of the second step disproportionation could be explained by nucleation and three-dimensional growth model.
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