Ruthenium/titanium oxide interface promoted electrochemical nitrogen reduction reaction

Abstract

The electrochemical nitrogen reduction reaction (eNRR) offers a promising strategy to synthesize ammonia at ambient conditions. However, the selectivity and yield of ammonia are greatly impeded by the slow kinetics of the eNRR and the competing hydrogen evolution reaction (HER). Herein, we find that by growing Ru nanoparticles on rutile TiO2, the intimate electronic coupling between Ru nanoparticles and TiO2 support is able to greatly promote the first protonation of N2 via an associative mechanism in the eNRR while suppressing the HER, resulting in a greatly improved ammonia Faradaic efficiency of 40.7% and yield of 10.4 μgNH3 h−1 cm−2geometric area at −0.15 V versus the reversible hydrogen electrode (RHE) in 0.5 M K2SO4 aqueous solution at room temperature and ambient pressure. Our work provides a general approach to achieve selective electrochemical reaction by controlling the binding strength of reactive intermediates via interface engineering.