H2 dissociative adsorption on Pt3Ti (111)-a density functional theory investigation

The catalytic property of the intermetallic compound Pt3Ti is investigated by studying the interaction of its (111) surface with hydrogen. The study is aimed to provide atomic scale understanding on the behavior of the compound towards hydrogen where previous experimental works showed conflicting observations. Result of this work will have implication to applications such as hydrogenation reactions where hydrogen molecules need to be split in order for the succeeding reaction to occur. Computational technique based on density functional theory is used to obtain the two-dimensional potential energy surface (2-D PES) which describes the energy variation of the system with H-H bond length, r, and distance from the substrate, z, i.e. U = U(r, z). The barrier to H2 dissociation and the binding energy of H atom at the different sites of the substrate are estimated, and the results are compared to that for pure Pt. Charge density distribution is used to explain how Ti atoms modify the surface of the compound relative to the surface of pure Pt. ii