Silver nanoparticles deposited on glassy carbon. Electrocatalytic activity for reduction of benzyl chloride.

A potentiostatic single-pulse technique was employed to prepare silver nanoclusters deposited on glassy carbon (GC) from CH3CN+0.1M LiCO4 plating solutions containing 1–2mM AgClO4. The morphology of the particles, obtained at a constant voltage pulse of variable duration, was examined by scanning electron microscopy. Clusters with particle diameter of 100–400nm, which are uniformly distributed over the GC surface, can be prepared on a time-scale of 30–90s. The Ag clusters exhibit remarkable electrocatalytic activity for the reduction of benzyl chloride. The supported Ag nanoclusters and bulk Ag metal have comparable electrocatalytic activities, both anticipating the reduction potential of PhCH2Cl by ca. 0.5V with respect to bare GC. The Ag-modified electrode was used in preparative scale electrocatalytic reduction of benzyl chloride in different experimental conditions. Good yields of toluene or phenylacetic acid were obtained, depending on experimental conditions, whereas no loss of catalytic activity could be observed, even when the electrode was repeatedly used over a period of several days.