On an Ion-Exchange Property of Manganese Dioxide

When manganese dioxide is shaken with an electrolyte solution, the cation is adsorbed and hydrogen ion is released: an ion exchange reaction takes place on the surface of the manganese dioxide. A simple method based on zinc ion exchange reaction is proposed to measure the ion exchange capacity of various manganese dioxides. Results have been compared to the surface area of those samples measured by the B.E.T. method based on nitrogen gas adsorption, and a fairly good proportionality was found between them. The mechanism of the ion exchange is correlated with the structure of a surface complex.