We investigate the catalytic property of the intermetallic compound Pt 3Ti by studying the interaction of its (111) surface with hydrogen. Based on density functional theory, we obtain the 2-D PES to estimate the barrier for H2 dissociation, and the binding energy of H atom at different sites of the substrate. The observed energetics can be explained in terms of the role played by the Ti atoms in the compound. Our results show that the Ti atoms function as inactive components that dilute the concentration of the active Pt components thus making the compound less active than Pt towards hydrogen
