Ruthenium doping: An effective strategy for boosting nitrite electroreduction to ammonia over titanium dioxide nanoribbon array

Electrochemical reduction of nitrite (NO 2 – ) not only removes NO 2 – contaminant but also produces high-added value ammonia (NH 3 ). This process, however, needs efficient and selective catalysts for NO 2 − -to-NH 3 conversion. In this study, Ruthenium doped titanium dioxide nanoribbon array supported on Ti plate (Ru–TiO 2 /TP) is proposed as an efficient electrocatalyst for the reduction of NO 2 − to NH 3 . When operated in 0.1 M NaOH containing NO 2 – , such Ru–TiO 2 /TP achieves an ultra-large NH 3 yield of 1.56 mmol h −1 cm −2 and a super-high Faradaic efficiency of 98.9%, superior to its TiO 2 /TP counterpart (0.46 mmol h −1 cm −2 , 74.1%). Furthermore, the reaction mechanism is studied by theoretical calculation.