First-principles simulations of hydrogen peroxide formation catalyzed by small neutral gold clusters

Energetics and dynamical pathways for hydrogen peroxide formation from H-2 and O-2 bound to neutral gold dimers and tetramers have been investigated by applying several strategies: T = 0 K geometry optimizations, constrained Car-Parrinello molecular dynamics simulations at T = 300 K and metadynamics at T = 300 K. The competing reaction channels for water and hydrogen peroxide formation have been found and characterized. In each case, the reaction barriers for Au cluster catalyzed proton transfer are less than 1 eV. Water formation is a competitive reaction channel, and the relative weight of H2O and H2O2 products may depend on the chosen Au cluster size. Dynamic simulations demonstrate the significance of the geometric fluxionality of small catalytic Au clusters. These results indicate that neutral Au clusters could work as catalysts in aerobic H2O2 formation in ambient conditions.