An Interfacially Alloyed Pt∧Ag Cathode Catalyst for the Electrochemical Reduction of Oxygen

An interfacially alloyed Pt-on-Ag natiostructure ((Pt0.5Ag)-Ag-boolean AND-B/C) was loaded on Vulcan XC-72 carbon to make a cathode (Pt0.5Ag)-Ag-boolean AND-B/C catalyst for the oxygen reduction reaction (ORR). The electrocatalytic performance Of this (Pt0.5Ag)-Ag-boolean AND-B/C catalyst was measured by reference to its unalloyed counterpart (Pt0.5Ag)-Ag-boolean AND-A/C and E-TEK Pt/C catalysts. The intrinsic activity of Pt in the (Pt0.5Ag)-Ag-boolean AND-B/C catalyst was identified to be twice that in the E-TEK Pt/C catalyst although the half-wave potentials (E-1/2) of the ORR curves over both catalysts were the same. Compared with the unalloyed (Pt0.5Ag)-Ag-boolean AND-A/C catalyst, the alloying at the Pt/Ag interface in the (Pt0.5Ag)-Ag-boolean AND-B/C catalyst gave a more positive E-1/2 and also a significantly higher mass-specific activity of Pt for ORR.