Engineering local environment of ruthenium by defect-tuned SnO2 over carbon cloth for neutral-media N2 electroreduction

Electrocatalytic N 2 reduction reaction (NRR) is of great potential as a sustainable and alternative technique to the energy-intensive Haber-Bosch process for NH 3 production. However, its practical applications are impeded by the low NH 3 yield and Faradaic efficiency (FE) mainly due to the inert N≡N triple bond and the competing hydrogen evolution reaction (HER). Herein, ruthenium-doped defect-rich SnO 2 nanoparticles on carbon cloth (Ru–SnO 2 /CC) are synthesized for efficient electrocatalytic NRR under ambient conditions. The catalysts exhibit an NH 3 yield of 4.83 μg h −1 cm − 2 with a FE of 17.01% at −0.2 V vs. reversible hydrogen electrode in 0.1 M Na 2 SO 4 . The integration of Ru species, SnO 2 and oxygen vacancies leads a synergistic catalytic system, in which the semiconducting SnO 2 particles not only stabilize the Ru active centers but also suppress the HER, while the oxygen vacancies in SnO 2 lattice help to promote the N 2 adsorption and enhance the activity of the Ru active centers. Overall, this synergy result in a unique local environment around the Ru active sites that favors the NRR process, which is further reinforced by the binder-free and facile electron transfer nature of CC, leading to the outstanding NRR catalytic activity and durability. These results outperform majority of the noble-metals-based electrocatalysts under similar conditions. This metal-doping tuned local environment manipulation may open up a promising avenue to the design and fabrication of efficient catalysts for N 2 electroreduction. A self-supporting electrocatalyst, Ru–SnO 2 /CC, exhibits excellent performance in neutral electrolyte towards N 2 electroreduction due to the synergistic effect provided by Ru active centers, SnO 2 , oxygen vacancies and carbon cloth. • Ru doped defect-rich SnO 2 nanoparticles decorated on carbon cloth are successfully fabricated. • Ru–SnO 2 /CC exhibits outstanding activity and selectivity towards N 2 electroreduction. • The crucial roles of engineering local environment are systematically investigated.