Journal of the Serbian Chemical Society (Nov 1999)
Oxygen reduction on single crystal platinum electrodes in phosphoric acid solutions
Abstract
Oxygen reduction reaction has been studied on Pt low index planes in 0.1 M and 85% H3PO4 using hanging meniscus rotating disc electrode technique. The first-order kinetics of O2 reduction reaction was found for all three surfaces in a four-electron process with the first electron transfer rate determining in both 0.1 M and 85% H2PO4 solutions. Catalytic activity for O2 reduction follows the sequence Pt (110)>>Pt (100)>>Pt (111). Structural dependence is predominantly determined by the adsorption of phosphoric acid anions, which is strongly structure-dependent on Pt surfaces.