Nanoelectrochemical approaches were used to investigate adsorption/desorption of hydrogen on Pt electrodes. These processes, which have been extensively studied over the last century, remain of current interest because of their applications in energy storage systems. The effective surface area of a nanoelectrode was found to be much larger than its geometric surface area due to surface diffusion of adsorbed redox species at the Pt/glass interface. An additional peak of hydrogen desorption was observed and attributed to the spillover of hydrogen from the Pt surface into glass. The results were compared to those obtained for underpotential deposition of copper on Pt nanoelectrodes