Platinum Monolayer Electrocatalysts for the Oxygen Reduction Reaction: Improvements Induced by Surface and Subsurface Modifications of Cores
Figure 2
(a) Polarization curves for O2 reduction on platinum monolayers (PtML) on Ru(0001), Ir(111), Rh(111), Au(111), and Pd(111) in a 0.1 M HClO4 solution on a disk electrode. The curve for Pt(111) is taken from [19, 20] and included for comparison. The rotation rate is 1600 rpm, and the sweep rate is 20 mVs−1 (50 mVs−1 for Pt(111)); = current density, RHE = reverible hydrogen electrode [6]. (b) Kinetic currents (, square symbols) at 0.8 V for O2 reduction on the platinum monolayers supported on different single-crystal surfaces in a 0.1 M HClO4 solution and calculated binding energies of atomic oxygen (BEo, filled circles) as functions of calculated d-band center (); relative to the Fermi level) of the respective clean platinum monolayers. The current data for Pt(111) is taken from [19, 20] and included for comparison. Labels: (1) PtML/Ru(0001), (2) PtML/Ir(111), (3) PtML/Rh(111), (4) PtML/Au(111), (5) Pt(111), and (6) PtML/Pd(111) [6].
