Recent developments on the rapid screening of electrocatalysts by scanning electrochemical microscopy

Scanning Electrochemical Microscopy is a scanning probe technique which is becoming a leading electrochemical technique. The possibility of using a movable microelectrode which can be scanned over a surface is one of the most attractive features. In turn, the substrate can assume different natures, from biological systems to electrocatalytic surface, from photoactive materials to nanostructured textures, thus making the technique extremely flexible. In the most recent years, SECM is being applied to study libraries of materials useful as electrocatalysts or photoelectrocatalysts in energy conversion devices 1-3 . In this work, recent results on the rapid screening of electrochemical activity of material libraries toward the oxygen evolution/reduction reactions are shown and discussed. The effectiveness of these methods is proved by digital simulations. Both methods were applied on model mixtures based on the Ir-O system, considered as promising materials for the preparation of operative devices. Experimental results obtained by SECM are confirmed by voltamperometric and physico-chemical techniques. 1. Férnandez J.L.,. Walsh D. A, Bard A.J., J. Am. Chem. Soc. 2005, 127, 357-365 2. Minguzzi, A.; Apulche-Aviles, M. A.; Rodriguez Lopez, J.; Rondinini, S.; Bard, A.J. Anal. Chem. 2008, 80, 4055. 3 Lee J., Ye H., Pan S., Bard A. J., Anal. Chem. 2008, 80, 7445