(718g) Universality in Oxygen Reduction On Metal Surfaces

In this presentation, we extend the activity volcano for oxygen reduction from the (111) facet to the (100) facet. We show that the recent findings of constant scaling between OOH and OH holds on the (100) metal facet as well. Using this fact, we show the existence of a universal activity volcano to describe oxygen reduction electrocatalysis with a minimum overpotential η_min = 0.37 ± 0.1 V. Specifically, we find that the (100) facet of Pt is found to bind oxygen intermediates too strongly and is not as active for ORR. In contrast, Au(100) facet is predicted to be much more active than Au(111) and comparable in activity to Pt-alloys. Using this ac- tivity volcano, we further predict that Au alloys that bind OH stronger could display improved ORR activity on the (100) facet. We carry out a computational search over candidate alloys and suggest that alloying Au with early transition metals could lead to materials that exhibit enhanced ORR activity. We also prescribe a simple principle in the choice of nanoparticle catalysts where the chosen catalyst should have its dense facet on the weak binding leg of the volcano so that its more open facets, defects could also be active.