Multiple Roles of Alkanethiolate‐Ligands in Direct Formation of H(2)O(2) over Pd Nanoparticles

Coadsorbed organic species including thiolates can promote direct synthesis of hydrogen peroxide from H(2) and O(2) over Pd particles. Here, density functional theory based kinetic modeling, augmented with activity measurements and vibrational spectroscopy are used to provide atomistic understanding of direct H(2)O(2) formation over alkylthiolate(RS) Pd. We find that the RS species are oxidized during reaction conditions yielding RSO(2) as the effective ligand. The RSO(2) ligand shows superior ability for proton transfer to the intermediate surface species OOH, which accelerates the formation of H(2)O(2). The ligands promote the selectivity also by blocking sites for unselective water formation and by modifying the electronic structure of Pd. The work rationalizes observations of enhanced selectivity of direct H(2)O(2) formation over ligand‐funtionalized Pd nanoparticles and shows that engineering of organic surface modifiers can be used to promote desired hydrogen transfer routes.