Oxide Relay: An Efficient Mechanism for Catalytic Water Oxidation at Hydrophobic Electrode Surfaces

In order to combine the advantages of molecular catalysts with the stability of solid-state catalysts, hybrid systems with catalysts immobilized on carbon nanotubes are prominent candidates. Here we explore our recent mechanistic proposal for Ru(tda)(py)₂, the oxide relay mechanism, in a hybrid system from an experimental study. It reacts with the same efficiency but with increased stability compared to the homogeneous molecular catalyst. We used the empirical valence bond method and molecular dynamics with enhanced sampling approaches to investigate the two key steps in the mechanism: the intramolecular O-O bond formation and the OH^- nucleophilic attack. The results on these calculations show that the oxide relay mechanism remains unaltered in the new environment. We believe that the principles should apply to other oxide containing dangling groups and to other metal centers, opening new possibilities of future developments on hybrid molecular catalyst-based water splitting devices.