Hydrogen Evolution Reaction on Platinum Catalyzed by Palladium and Rhodium Nanoislands

• Pd and Rh nanoislands are deposited spontaneously on Pt(poly).
• Pd/Pt(poly) and Rh/Pt(poly) surfaces are characterized by height and phase AFM.
• Saturation coverage of Pd and Rh nanoislands was 53% and 75%, respectively.
• Both bimetallic surfaces catalyzed HER in alkaline media with respect to bare Pt.
• Enhanced catalysis for HER is ascribed to the synergistic electronic effect.

Pd/Pt(poly) and Rh/Pt(poly) bimetallic electrodes prepared by spontaneous deposition of Pd and Rh nanoislands on Pt(poly) at submonolayer coverage were explored as catalysts for hydrogen evolution reaction (HER) in alkaline media. Characterization of bimetallic surfaces was performed ex situ by height and phase AFM imaging and in situ by cyclic voltammetry. HER was investigated by linear sweep voltammetry in 0.1 M NaOH. Both Pd/Pt(poly) and Rh/Pt(poly) surfaces exhibited an enhanced catalysis for HER with respect to bare Pt(poly), which is explained by a strong synergistic electronic effect of platinum substrate on the deposited Pd or Rh nanoislands. This electronic effect leads to the lowering of a binding energy of adsorbed hydrogen intermediate and consequently to the lowering of the overpotential for HER.

Figure optionsDownload as PowerPoint slide