Oxygen reduction on a platinum cluster

The reaction Pt5O2(ads)+H+(aq)+e−→Pt5–OOH is analyzed on the basis of density functional theory calculations. It is found that the electron transfer process takes place gradually as the hydronium ion gets close to the adsorbed oxygen. At a certain small Oads–H⋯Owater distance, the barrier for proton and electron transfer becomes negligible. The effect of an electric field on the reaction is studied by charging the metal/adsorbate complex, and that of a solvation shell on the proton transfer process is explored by using the H3O+(H2O)2 ion cluster to model the hydrated proton.