Journal
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
Volume 110, Issue 2, Pages 601-610Publisher
SPRINGER
DOI: 10.1007/s10973-011-2000-0
Keywords
Congruent dissociative vaporization; Gas-solid reaction mechanism; Oxide reduction kinetics; Third-law methodology
Ask authors/readers for more resources
The thermochemical approach to analysis of thermal decomposition of solids, developed earlier by L'vov, is extended here, for the first time, to interpret the kinetics and mechanism of the reduction of an oxide (NiO) by a gas (H-2). This approach is based on the mechanism of congruent dissociative vaporization of the reactant, Langmuir kinetics and determination of the Arrhenius E parameter by the third-law method. The calculated enthalpy of the reaction is in good agreement with the experimentally measured E value. Many other mechanistic and kinetic features of the reaction are explained within the framework of the given theoretical approach. These include: the formation of metal nuclei; the initial autocatalytic behavior; the formation of nanocrystalline structure of the reduced metal product; the equimolar and isobaric modes of reduction; the dependence of reduction rate on hydrogen pressure; the more than twofold decrease of the E parameter with the extent of reaction alpha, and the systematic increase of E with temperature.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available