Electrocatalytic nitrate reduction on palladium based catalysts activated with germanium

The electrocatalytic reduction of nitrate has been studied with electrochem ical methods on palladium and palladium-platinum electrodes activated with germanium. The formation of a palladium-germanium alloy that occurs at germ anium coverage above 0.2 has a strong enhancing effect on the rate of nitra te reduction, whereas the reaction rate is low for germanium coverage below 0.2. Palladium electrodes covered with a submonolayer platinum are effecti vely activated by a low germanium coverage. Cyclic voltammetry of adsorbed NO shows that the higher reactivity of palladium-platinum electrodes in the nitrate reduction is related to the higher reactivity of platinum towards NO reduction as compared to palladium. (C) 1999 Elsevier Science B.V. All r ights reserved.