EFFECT OF THE DOPING OF A METAL-OXIDE BY PLATINUM ON ITS OXIDIZING PROPERTIES

Oxidation is very slow on supported metals or oxides whose contact sur face between the catalytic active phase and the carbonaceous particle to burn in poor. On the contrary, some pure oxides are more active. Ox idation by oxygen proceeds by partial reduction of the oxide and the r ate-determining step of the reaction is the reoxidation of the reduced solid. Addition of a small amount of platinum catalyzes that reoxidat ion.