Hydrogen spillover at sub-2 nm Pt nanoparticles by electrochemical hydrogen loading

Hydrogen generation and storage is an essential component in the increasingly important field of energy storage. Electrochemical generation of hydrogen atoms at the surface of Pt like metals at select potentials is a widely accepted phenomenon. However, moving these adsorbed hydrogen atoms to high surface area support systems for storage is an issue. We show spillover of these adsorbed hydrogen atoms to the supporting structure for sub-2 nm Pt nanoparticles sputtered on Fluorine Doped Tin Oxide (FTO) and on few layer graphene (FLG) supports. Evidence of size-dependent hydrogen spillover was observed for Pt nanoparticles deposited using tilted target sputtering and a correlation between nanoparticle size, crystallinity, support characteristics, and hydrogen spillover is also reported. Evidence of C-H bonds formed on the FLG surface due to H spillover from 0.9 nm Pt nanoparticles was also confirmed through XPS analysis.