ACTIVE SURFACE-AREA DETERMINATION OF PD-SI ALLOYS BY H-ADSORPTION

The active surface area of a Pd-Si alloy (80-20 at.%) was determined b y means of the anodic charge associated to the desorption peaks of und erpotential deposited hydrogen atoms. The value found was very close t o that expected for a complete monolayer of Pd-H, considering the perc entage of Pd on the surface. The results are comparable to those obtai ned by the classical cyclic voltammetric method of reduction of oxides grown at different inversion potentials. The agreement suggests that one full monolayer of adsorbed hydrogen is formed on the Pd portion of the alloy surface. Copyright (C) 1996 Elsevier Science Ltd