Insights into dynamic evolution of surface oxidized Pd clusters for efficient hydrogen peroxide production

The direct synthesis of H2O2 from H-2 and O-2 involves the structural evolution of nano-sized catalyst during highly exothermic process, ultimately resulting in catalyst deactivation. The mechanism of catalyst structural evolution and its impact on the catalytic performance were elucidated by combining theoretical calculations with experimental characterizations. Through theoretical calculations, the dynamic evolution of surface-oxidized Pd-12 clusters loaded on graphene (Pd-12@G) during the reaction process was demonstrated. Different oxygen concentrations and reactants can lead to the evolution of the catalyst and consequently to the changes in catalytic activity. The relaxed Pd-12@G with a doped O atom exhibits an ultra-low reaction energy of similar to 0.20 eV for H2O2 production. The experimental findings also confirm the dynamic variation of the palladium oxide catalyst during the reaction. This work provides a microscopic understanding of the complex catalyst-reactant interaction, and casts helpful insights into the catalyst deactivation during the synthesis of hydrogen peroxide.