Additional methodologies for activity, selectivity, and density functional theory (DFT) calculations are provided in the SI. Prior to activity and selectivity measurements, TM foils were cleaned by etching in a 1:4 ratio of hydrochloric acid to water for 30 seconds, followed by rinsing in water and drying under dinitrogen flow. While this etching step is intended to provide a reproducible surface composition for monometallic TM foils, it may induce compositional variability in the Ni0.68Cu0.32 alloy used in this study (see note in Figure ).