Hydrogen Adsorption on Platinum-Gold Bimetallic Nanoparticles: A Density Functional Theory Study

Using ab initio density functional theory, we investigate how hydrogen interacts with Pt-Au bimetallic nanoparticles (NPs) of various compositions. Several Au, Pt, and Pt Au NPs of 85 atoms are considered. The results indicate that both the adsorption energy and the geometry of the most favorable adsorption sites are dependent on the local distribution of metal atoms. On some adsorption sites, our results suggest that the hydrogen adsorption on Pt Au NPs can be more favorable than that on monometallic Pt NPs of similar size. The results are interpreted with the aid of a number of electronic structure details, including d-band structure, density of states, electronic population, and charge density differences.