Nitrate is a micronutrient and a potential carcinogen. Its removal from drinking water is essential to safe guard the public and ecological health. Previous studies have demonstrated that nitrate reduction in acidic solution is fast and easy toward the formation of ammonium final product. However, nitrate reduction to environmentallybenign molecular nitrogen is necessary in order to control water quality in totality. This presentation will discuss our strategy on electrode preparation as to manipulate nitrate reactivity and nitrogen selectivity in electrochemical nitrate reduction. The preparation of tin-palladium electrodes was attempted using electrode deposition approach on stainless steel support. Different electrodeposition programs, such as charging processes and composition of metal solution affected the crystal structure and surface morphology of bimetallic electrodes, thereby impacted nitrate reduction capability. Based on XRD and analysis of reaction products, nitrate reduction over the synthesized Sn-Pd bimetallic electrodes was surface-structure sensitive; the fraction of (420) crystal facet of the Sn₃Pd alloy exhibited critical effect on the reactivity and selectivity of nitrate reduction. Of the most significance, electrode prepared with one batch of solution containing both SnCl₂ and PdCl₂ at molar ratio of 1 to 4 exhibited the best performance in nearly 100% nitrate conversion and 81% nitrogen yield.
