Structural effects in electrocatalysis: Oxygen and hydrogen peroxide reduction on single crystal gold electrodes and the effects of lead ad-atoms

Structural effects in electrocatalysis have been clearly and definitely demonstrated for example in the oxidation of HCOOH, CH3OH and CH2O on platinum single crystal electrodes. In this note, we report considerable structural effects on the kinetics of the 02 and HO2 reduction on gold single crystal electrodes with (111), (110) and (100) orientations

Synergy of Cobalt and Silver Microparticles Electrodeposited on Glassy Carbon for the Electrocatalysis of the Oxygen Reduction Reaction: An Electrochemical Investigation

The combination of two different metals, each of them acting on different steps of the oxygen reduction reaction (ORR), yields synergic catalytic effects. In this respect, the electrocatalytic effect of silver is enhanced by the addition of cobalt, which is able to break the O–O bond of molecular oxygen, thus accelerating the first step of the reduction mechanism. At the same time, research is to further reduce the catalyst’s cost, reducing the amount of Ag, which, even though being much less expensive than Pt, is still a noble metal. From this point of view, using a small amount of Ag together with an inexpensive material, such as graphite, represents a good compromise. The aim of this work was to verify if the synergic effects are still operating when very small amounts of cobalt (2–10 μg·cm−2) are added to the microparticles of silver electrodeposited on glassy carbon, described in a preceding paper from us. To better stress the different behaviour observed when cobalt and silver are contemporarily present in the deposit, the catalytic properties of cobalt alone were investigated. The analysis was completed by the Levich plots to evaluate the number of electrons involved and by Tafel plots to show the effects on the reaction mechanism