Abstract:
The oxidation of hydrogen on platinum has been studied using a microcalorimctric technique. The reaction takes place by two mechanisms depending on whether the surface is in an oxidised or reduced state. On the reduced surface, hydrogen is dissociativcly adsorbed and competes with adsorbed molecular oxygen for adsorption sites. The reaction rate Ls higher on the oxidised surface where hydrogen molecules are weakly adsorbed and react with strongly adsorbed oxygen.