THE ELECTROCHEMICAL REDUCTION OF OXYGEN ON POLYCRYSTALLINE COPPER IN BORAX BUFFER

Oxygen reduction proceeds on copper electrodes in boric + borate buffe r by the four electron pathway. Difference reflectance spectroscopy sh ows that surface oxide species are formed during oxygen reduction on p re-reduced copper. The redox couple Cu2O/CuO plays an important role i n the reduction sequence and a CE mechanism is proposed, although dire ct electron transfer to the oxygen molecule from oxide-free surfaces a ppears possible. In this case, the behaviour of copper is similar to t hat of the isoelectronic metal gold.