The Thermal Decomposition and Reduction of Silver(I) Oxide

Abstract

The thermal decomposition of silver(I) oxide and its reduction with reductive gases, such as ethylene, hydrogen, and carbon monoxide, have been studied by using a fixed-bed flow reactor. Under isothermal conditions, each reaction gave a sigmoidal shape to the fractional decomposition vs. time curves, and these curves were in good agreement with Avrami’s equation. The temperature at which the reaction commenced corresponded well to the chemical affinity of the reaction, and a linear free-energy relationship holds between the apparent activation energy and the standard enthalpy change of the reaction. In the thermal decomposition, an enlargement in particle size resulting from the melting and sintering of the product silver was recognized, but in the reduction the particle size scarcely varied during the reaction. On the basis of these results, the mechanism of each reaction was discussed.