PARTICLE-SIZE EFFECTS FOR OXYGEN REDUCTION ON DISPERSED SILVER PLUS CARBON ELECTRODES IN ALKALINE-SOLUTION

Ag + C electrocatalysts with different Ag particle-size distributions were prepared by functional ion preadsorption method. The effects of the preadsorption of different halogen ions on carbon on Ag particle size and crystal structure were studied by transmission electron microscopy and a selected area diffraction method, The adsorption characteristics of Ag+ on activated carbon were measured by an argentimetry method. The catalytic behaviour of Ag + C catalysts with different Ag particle size distributions for oxygen reduction in KOH solution was investigated using a soft-embedded microelectrode and a soft-embedded rotating disc electrode with a platinum ring electrode. The results showed that oxygen reduction was a structure-sensitive reaction on silver particles. Decreased Ag particle size has a complicated effect on the four-electron reduction, but a favourable effect on two-electron reduction.